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Park Y, Kim W, Cha Y, Kim M, Park W. Alleviation of H 2O 2 toxicity by extracellular catalases in the phycosphere of Microcystis aeruginosa. HARMFUL ALGAE 2024; 137:102680. [PMID: 39003030 DOI: 10.1016/j.hal.2024.102680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 05/20/2024] [Accepted: 06/16/2024] [Indexed: 07/15/2024]
Abstract
High levels of environmental H2O2 represent a threat to many freshwater bacterial species, including toxic-bloom-forming Microcystis aeruginosa, particularly under high-intensity light conditions. The highest extracellular catalase activity-possessing Pseudoduganella aquatica HC52 was chosen among 36 culturable symbiotic isolates from the phycosphere in freshly collected M. aeruginosa cells. A zymogram for catalase activity revealed the presence of only one extracellular catalase despite the four putative catalase genes (katA1, katA2, katE, and srpA) identified in the newly sequenced genome (∼6.8 Mb) of P. aquatica HC52. Analysis of secreted catalase using liquid chromatography-tandem mass spectrometry was identified as KatA1, which lacks a typical signal peptide, although the underlying mechanism for its secretion is unknown. The expression of secreted KatA1 appeared to be induced in the presence of H2O2. Proteomic analysis also confirmed the presence of KatA1 inside the outer membrane vesicles secreted by P. aquatica HC52 following exposure to H2O2. High light intensities (> 100 µmol m-2 s-1) are known to kill catalase-less axenic M. aeruginosa cells, but the present study found that the presence of P. aquatica cells supported the growth of M. aeruginosa, while the extracellular catalases in supernatant or purified form also sustained the growth of M. aeruginosa under the same conditions. Our results suggest that the extracellular catalase secreted by P. aquatica HC52 enhances the tolerance of M. aeruginosa to H2O2, thus promoting the formation of M. aeruginosa blooms under high light intensities.
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Affiliation(s)
- Yerim Park
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, Republic of Korea
| | - Wonjae Kim
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, Republic of Korea
| | - Yeji Cha
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, Republic of Korea
| | - Minkyung Kim
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, Republic of Korea
| | - Woojun Park
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, Republic of Korea.
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2
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Gupta S, Biswas P, Das B, Mondal S, Gupta P, Das D, Mallick AI. Selective depletion of Campylobacter jejuni via T6SS dependent functionality: an approach for improving chickens gut health. Gut Pathog 2024; 16:38. [PMID: 38997758 PMCID: PMC11245787 DOI: 10.1186/s13099-024-00628-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Accepted: 06/28/2024] [Indexed: 07/14/2024] Open
Abstract
The targeted depletion of potential gut pathogens is often challenging because of their intrinsic ability to thrive in harsh gut environments. Earlier, we showed that Campylobacter jejuni (C. jejuni) exclusively uses the Type-VI Secretion System (T6SS) to target its prey such as Escherichia coli (E. coli), and phenotypic differences between T6SS-negative and T6SS-positive C. jejuni isolates toward bile salt sensitivity. However, it remains unclear how the target-driven T6SS functionality prevails in a polymicrobial gut environment. Here, we investigated the fate of microbial competition in an altered gut environment via bacterial T6SS using a T6SS-negative and -positive C. jejuni or its isogenic mutant of the hemolysin-coregulated protein (hcp). We showed that in the presence of bile salt and prey bacteria (E. coli), T6SS-positive C. jejuni experiences enhanced intracellular stress leading to cell death. Intracellular tracking of fluorophore-conjugated bile salts confirmed that T6SS-mediated bile salt influx into C. jejuni can enhance intracellular oxidative stress, affecting C. jejuni viability. We further investigated whether the T6SS activity in the presence of prey (E. coli) perturbs the in vivo colonization of C. jejuni. Using chickens as primary hosts of C. jejuni and non-pathogenic E. coli as prey, we showed a marked reduction of C. jejuni load in chickens cecum when bile salt solution was administered orally. Analysis of local antibody responses and pro-inflammatory gene expression showed a reduced risk of tissue damage, indicating that T6SS activity in the complex gut environment can be exploited as a possible measure to clear the persistent colonization of C. jejuni in chickens.
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Affiliation(s)
- Subhadeep Gupta
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia, West Bengal, 741246, India
| | - Prakash Biswas
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia, West Bengal, 741246, India
| | - Bishnu Das
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia, West Bengal, 741246, India
| | - Samiran Mondal
- Department of Veterinary Pathology, West Bengal University of Animal and Fishery Sciences, Kolkata, West Bengal, 700037, India
| | - Parna Gupta
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia, West Bengal, 741246, India
| | - Dipjyoti Das
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia, West Bengal, 741246, India.
| | - Amirul Islam Mallick
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia, West Bengal, 741246, India.
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Lu W, Lu H, Huo X, Wang C, Zhang Z, Zong B, Wang G, Dong W, Li X, Li Y, Chen H, Tan C. EvfG is a multi-function protein located in the Type VI secretion system for ExPEC. Microbiol Res 2024; 283:127647. [PMID: 38452551 DOI: 10.1016/j.micres.2024.127647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 01/22/2024] [Accepted: 02/10/2024] [Indexed: 03/09/2024]
Abstract
The Type VI secretion system (T6SS) functions as a protein transport nanoweapon in several stages of bacterial life. Even though bacterial competition is the primary function of T6SS, different bacteria exhibit significant variations. Particularly in Extraintestinal pathogenic Escherichia coli (ExPEC), research into T6SS remains relatively limited. This study identified the uncharacterized gene evfG within the T6SS cluster of ExPEC RS218. Through our experiments, we showed that evfG is involved in T6SS expression in ExPEC RS218. We also found evfG can modulate T6SS activity by competitively binding to c-di-GMP, leading to a reduction in the inhibitory effect. Furthermore, we found that evfG can recruit sodA to alleviate oxidative stress. The research shown evfG controls an array of traits, both directly and indirectly, through transcriptome and additional tests. These traits include cell adhesion, invasion, motility, drug resistance, and pathogenicity of microorganisms. Overall, we contend that evfG serves as a multi-functional regulator for the T6SS and several crucial activities. This forms the basis for the advancement of T6SS function research, as well as new opportunities for vaccine and medication development.
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Affiliation(s)
- Wenjia Lu
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China; Hubei Hongshan Laboratory, Wuhan, China; Key Laboratory of Preventive Veterinary Medicine in Hubei Province, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, China
| | - Hao Lu
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, China
| | - Xinyu Huo
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, China
| | - Chenchen Wang
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, China
| | - Zhaoran Zhang
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, China
| | - Bingbing Zong
- School of animal science and nutrition engineering, Wuhan Polytechnic University, Wuhan 430023, China
| | - Gaoyan Wang
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, China
| | - Wenqi Dong
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, China
| | - Xiaodan Li
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, China
| | - Yuying Li
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, China
| | - Huanchun Chen
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China; Hubei Hongshan Laboratory, Wuhan, China; Key Laboratory of Preventive Veterinary Medicine in Hubei Province, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, China
| | - Chen Tan
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China; Hubei Hongshan Laboratory, Wuhan, China; Key Laboratory of Preventive Veterinary Medicine in Hubei Province, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, China.
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Dessartine MM, Kosta A, Doan T, Cascales É, Côté JP. Type 1 fimbriae-mediated collective protection against type 6 secretion system attacks. mBio 2024; 15:e0255323. [PMID: 38497656 PMCID: PMC11005336 DOI: 10.1128/mbio.02553-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 01/25/2024] [Indexed: 03/19/2024] Open
Abstract
Bacterial competition may rely on secretion systems such as the type 6 secretion system (T6SS), which punctures and releases toxic molecules into neighboring cells. To subsist, bacterial targets must counteract the threats posed by T6SS-positive competitors. In this study, we used a comprehensive genome-wide high-throughput screening approach to investigate the dynamics of interbacterial competition. Our primary goal was to identify deletion mutants within the well-characterized E. coli K-12 single-gene deletion library, the Keio collection, that demonstrated resistance to T6SS-mediated killing by the enteropathogenic bacterium Cronobacter malonaticus. We identified 49 potential mutants conferring resistance to T6SS and focused our interest on a deletion mutant (∆fimE) exhibiting enhanced expression of type 1 fimbriae. We demonstrated that the presence of type 1 fimbriae leads to the formation of microcolonies and thus protects against T6SS-mediated assaults. Collectively, our study demonstrated that adhesive structures such as type 1 fimbriae confer collective protective behavior against T6SS attacks.IMPORTANCEType 6 secretion systems (T6SS) are molecular weapons employed by gram-negative bacteria to eliminate neighboring microbes. T6SS plays a pivotal role as a virulence factor, enabling pathogenic gram-negative bacteria to compete with the established communities to colonize hosts and induce infections. Gaining a deeper understanding of bacterial interactions will allow the development of strategies to control the action of systems such as the T6SS that can manipulate bacterial communities. In this context, we demonstrate that bacteria targeted by T6SS attacks from the enteric pathogen Cronobacter malonaticus, which poses a significant threat to infants, can develop a collective protective mechanism centered on the production of type I fimbriae. These adhesive structures promote the aggregation of bacterial preys and the formation of microcolonies, which protect the cells from T6SS attacks.
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Affiliation(s)
- Margot Marie Dessartine
- Département de biologie, Faculté des sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Artemis Kosta
- Plateforme de microscopie, Institut de Microbiologie de la Méditerranée (IMM, FR3479), Aix-Marseille Univ, CNRS, Marseille, France
| | - Thierry Doan
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM, UMR7255), Institut de Microbiologie de la Méditerranée, Aix Marseille Univ, CNRS, Marseille, France
| | - Éric Cascales
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM, UMR7255), Institut de Microbiologie de la Méditerranée, Aix Marseille Univ, CNRS, Marseille, France
| | - Jean-Philippe Côté
- Département de biologie, Faculté des sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
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Li Y, Jv M, Zhuang Y, Zhao X, Hu X. A hypervirulent Acinetobacter baumannii strain has robust anti-phagocytosis ability. BMC Microbiol 2024; 24:106. [PMID: 38561652 PMCID: PMC10983618 DOI: 10.1186/s12866-024-03264-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Accepted: 03/17/2024] [Indexed: 04/04/2024] Open
Abstract
BACKGROUND Acinetobacter baumannii (A. baumannii) is associated with both hospital-acquired infections (HAP) and community-acquired pneumonia (CAP). In this study, we present a novel CAP-associated A. baumannii (CAP-AB) strain causing severe pneumonia in an afore healthy male patient without underlying conditions. Subsequently, we investigated the pathogenicity and immunogenicity of this CAP-AB strain using a mice pneumonia model. RESULTS A 58-year-old male patient with no underlying conditions experienced worsening symptoms of a productive cough, sputum, and fever that developed acutely, in just 24 h. The diagnosis was severe community-acquired pneumonia (CAP) and type-1 respiratory failure. An A. baumannii strain was isolated from his sputum and blood cultures. To gain a deeper understanding of the rapid progression of its pathology, we utilized the CAP-associated A. baumannii strain YC128, a previously obtained hospital-acquired pneumonia A. baumannii (HAP-AB) strain YC156, and a highly virulent A. baumannii control strain LAC-4 to construct a mouse pneumonia model, and subsequently compared the mortality rate of the three groups. Following inoculation with 107 CFU of A. baumannii, the mortality rate for the YC128, LAC-4, and YC156 groups was 60% (6/10), 30% (3/10), and 0%, respectively. The bacterial burden within the pulmonary, liver, and spleen tissues of mice in the YC128 group was significantly higher than that of the YC156 group, and slightly higher than that of the LAC-4 group. Pathological analysis of lung tissue using HE-staining revealed that the inflammatory pathological changes in mice from the YC128 group were significantly more severe than those in the YC156 group. Additionally, CT scan images displayed more pronounced inflammation in the lungs of mice from the YC128 group compared to the YC156 group. Local levels of cytokines/chemokines such as IL-1β, IL-6, TNF-α, and CXCL1 were assessed via RT-qPCR in lung tissues. In comparison with the YC156 strain, the highly virulent YC128 strain induced the expression of proinflammatory cytokines more rapidly and severely. Furthermore, we examined the in vitro anti-phagocytosis ability of YC128 and YC156 strains against mice peritoneal macrophages, revealing that the highly virulent YC128 isolate displayed greater resistance to macrophage uptake in contrast to YC156. Results from Whole Genome Sequencing (WGS) indicated that YC128 harbored a complete type VI secretion system (T6SS) gene cluster, while YC156 lacked the majority of genes within the T6SS gene cluster. The other virulence-related genes exhibited minimal differences between YC128 and YC156. Drawing from previous studies, we postulated that the T6SS is linked to the hypervirulence and robust anti-phagocytic ability of YC128. CONCLUSIONS This article reports on the isolation of a novel hypervirulent CAP-AB strain, YC128, from a severe CAP patient. The results demonstrate that this CAP-AB strain, YC128, is capable of inducing fatal pneumonia and extrapulmonary dissemination in a mouse pneumonia model. Moreover, this highly virulent CAP-AB strain exhibits significantly stronger anti-phagocytic abilities compared to the HAP-AB YC156 strain. Genome sequencing comparisons reveal that the heightened hypervirulence and enhanced anti-phagocytosis abilities observed in YC128 may be attributed to the presence of the T6SS.
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Affiliation(s)
- Yan Li
- Division of Infectious Diseases, Yichun People's Hospital, Yichun, Jiangxi Province, China
| | - Mohan Jv
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China
| | - Yuan Zhuang
- Department of Infectious Diseases, People's Hospital of Rizhao, Ri Zhao, Shandong Province, China
| | - Xu Zhao
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China.
- Department of Infectious Diseases, Huashan Hospital Fujian Campus, Fudan University, Fuzhou, Fujian Province, China.
| | - Xiaoxiong Hu
- Division of Infectious Diseases, Yichun People's Hospital, Yichun, Jiangxi Province, China.
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Yin R, Cheng J, Lin J. The role of the type VI secretion system in the stress resistance of plant-associated bacteria. STRESS BIOLOGY 2024; 4:16. [PMID: 38376647 PMCID: PMC10879055 DOI: 10.1007/s44154-024-00151-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 01/26/2024] [Indexed: 02/21/2024]
Abstract
The type VI secretion system (T6SS) is a powerful bacterial molecular weapon that can inject effector proteins into prokaryotic or eukaryotic cells, thereby participating in the competition between bacteria and improving bacterial environmental adaptability. Although most current studies of the T6SS have focused on animal bacteria, this system is also significant for the adaptation of plant-associated bacteria. This paper briefly introduces the structure and biological functions of the T6SS. We summarize the role of plant-associated bacterial T6SS in adaptability to host plants and the external environment, including resistance to biotic stresses such as host defenses and competition from other bacteria. We review the role of the T6SS in response to abiotic factors such as acid stress, oxidation stress, and osmotic stress. This review provides an important reference for exploring the functions of the T6SS in plant-associated bacteria. In addition, characterizing these anti-stress functions of the T6SS may provide new pathways toward eliminating plant pathogens and controlling agricultural losses.
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Affiliation(s)
- Rui Yin
- Shaanxi Key Laboratory of Chinese Jujube, College of Life Sciences, Yan'an University, Yan'an, 716000, Shaanxi, China
| | - Juanli Cheng
- Shaanxi Key Laboratory of Chinese Jujube, College of Life Sciences, Yan'an University, Yan'an, 716000, Shaanxi, China
| | - Jinshui Lin
- Shaanxi Key Laboratory of Chinese Jujube, College of Life Sciences, Yan'an University, Yan'an, 716000, Shaanxi, China.
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Li C, Wei Z, He X, He H, Liu Y, Zuo Y, Xiao H, Wang Y, Shen X, Zhu L. OxyR-regulated T6SS functions in coordination with siderophore to resist oxidative stress. Microbiol Spectr 2024; 12:e0323123. [PMID: 38189330 PMCID: PMC10846153 DOI: 10.1128/spectrum.03231-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 12/02/2023] [Indexed: 01/09/2024] Open
Abstract
The formation of reactive oxygen species is harmful and can destroy intracellular macromolecules such as lipids, proteins, and DNA, even leading to bacterial death. To cope with this situation, microbes have evolved a variety of sophisticated mechanisms, including antioxidant enzymes, siderophores, and the type VI secretion system (T6SS). However, the mechanism of oxidative stress resistance in Cupriavidus pinatubonensis is unclear. In this study, we identified Reut_A2805 as an OxyR ortholog in C. pinatubonensis, which positively regulated the expression of T6SS1 by directly binding to its operon promoter region. The study revealed that OxyR-regulated T6SS1 combats oxidative stress by importing iron into bacterial cells. Moreover, the T6SS1-mediated outer membrane vesicles-dependent iron acquisition pathway played a crucial role in the oxidative stress resistance process. Finally, our study demonstrated that the T6SS1 and siderophore systems in C. pinatubonensis exhibit different responses in combating oxidative stress under low-iron conditions, providing a comprehensive understanding of how bacterial iron acquisition systems function in diverse conditions.IMPORTANCEThe ability to eliminate reactive oxygen species is crucial for bacterial survival. Continuous formation of hydroperoxides can damage metalloenzymes, disrupt DNA integrity, and even result in cell death. While various mechanisms have been identified in other bacterial species to combat oxidative stress, the specific mechanism of oxidative stress resistance in C. pinatubonensis remains unclear. The importance of this study is that we elucidate the mechanism that OxyR-regulated T6SS1 combats oxidative stress by importing iron with the help of bacterial outer membrane vesicle. Moreover, the study highlights the contrasting responses of T6SS1- and siderophore-mediated iron acquisition systems to oxidative stress. This study provides a comprehensive understanding of bacterial iron acquisition and its role in oxidative stress resistance in C. pinatubonensis under low-iron conditions.
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Affiliation(s)
- Changfu Li
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Zhiyan Wei
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Xinquan He
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Haiyang He
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Yuqi Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Yuxin Zuo
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - He Xiao
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Yao Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Xihui Shen
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Lingfang Zhu
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
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Leung PB, Matanza XM, Roche B, Ha KP, Cheung HC, Appleyard S, Collins T, Flanagan O, Marteyn BS, Clements A. Shigella sonnei utilises colicins during inter-bacterial competition. MICROBIOLOGY (READING, ENGLAND) 2024; 170:001434. [PMID: 38376387 PMCID: PMC10924462 DOI: 10.1099/mic.0.001434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 01/25/2024] [Indexed: 02/21/2024]
Abstract
The mammalian colon is one of the most densely populated habitats currently recognised, with 1011-1013 commensal bacteria per gram of colonic contents. Enteric pathogens must compete with the resident intestinal microbiota to cause infection. Among these enteric pathogens are Shigella species which cause approximately 125 million infections annually, of which over 90 % are caused by Shigella flexneri and Shigella sonnei. Shigella sonnei was previously reported to use a Type VI Secretion System (T6SS) to outcompete E. coli and S. flexneri in in vitro and in vivo experiments. S. sonnei strains have also been reported to harbour colicinogenic plasmids, which are an alternative anti-bacterial mechanism that could provide a competitive advantage against the intestinal microbiota. We sought to determine the contribution of both T6SS and colicins to the anti-bacterial killing activity of S. sonnei. We reveal that whilst the T6SS operon is present in S. sonnei, there is evidence of functional degradation of the system through SNPs, indels and IS within key components of the system. We created strains with synthetically inducible T6SS operons but were still unable to demonstrate anti-bacterial activity of the T6SS. We demonstrate that the anti-bacterial activity observed in our in vitro assays was due to colicin activity. We show that S. sonnei no longer displayed anti-bacterial activity against bacteria that were resistant to colicins, and removal of the colicin plasmid from S. sonnei abrogated anti-bacterial activity of S. sonnei. We propose that the anti-bacterial activity demonstrated by colicins may be sufficient for niche competition by S. sonnei within the gastrointestinal environment.
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Affiliation(s)
- P. B. Leung
- Department of Life Sciences, South Kensington Campus, Imperial College London, London, SW72AZ, UK
| | - X. M. Matanza
- Department of Life Sciences, South Kensington Campus, Imperial College London, London, SW72AZ, UK
| | - B. Roche
- Universite de Strasbourg, Institut de Biologie Moléculaire et Cellulaire, CNRS UPR9002, F-67000 Strasbourg, France
| | - K. P. Ha
- Department of Life Sciences, South Kensington Campus, Imperial College London, London, SW72AZ, UK
| | - H. C. Cheung
- Department of Life Sciences, South Kensington Campus, Imperial College London, London, SW72AZ, UK
| | - S. Appleyard
- Department of Life Sciences, South Kensington Campus, Imperial College London, London, SW72AZ, UK
| | - T. Collins
- Department of Life Sciences, South Kensington Campus, Imperial College London, London, SW72AZ, UK
| | - O. Flanagan
- Department of Life Sciences, South Kensington Campus, Imperial College London, London, SW72AZ, UK
| | - B. S. Marteyn
- Universite de Strasbourg, Institut de Biologie Moléculaire et Cellulaire, CNRS UPR9002, F-67000 Strasbourg, France
- University of Strasbourg Institute for Advanced Study (USIAS), F-67000 Strasbourg, France
- Institut Pasteur, Université de Paris, Inserm U1225, Unité de Pathogenèse des Infections Vasculaires, F-75015 Paris, France
| | - A. Clements
- Department of Life Sciences, South Kensington Campus, Imperial College London, London, SW72AZ, UK
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Jia F, Peng X, Yang X, Qiu S, Jia S, Ran T, Wang W, Xu D. PqqF inhibits T6SS secretion by decreasing the pH in Serratia marcescens FS14. FEMS Microbiol Lett 2024; 371:fnae047. [PMID: 38908910 DOI: 10.1093/femsle/fnae047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 05/21/2024] [Accepted: 06/21/2024] [Indexed: 06/24/2024] Open
Abstract
Pyrroloquinoline quinone (PQQ) is a redox cofactor with numerous important physiological functions, and the type VI secretion system (T6SS) is commonly found in Gram-negative bacteria and plays important roles in physiological metabolism of the bacteria. In this study, we found that the deletion of pqqF enhanced the secretion of Hcp-1 in Serratia marcesens FS14 in M9 medium. Transcriptional analysis showed that the deletion of pqqF almost had no effect on the expression of T6SS-1. Further study revealed that the increased secretion of Hcp-1 was altered by the pH changes of the culture medium through the reaction catalyzed by the glucose dehydrogenases in FS14. Finally, we demonstrated that decreased pH of culture medium has similar inhibition effects as PQQ induced on the secretion of T6SS-1. This regulation mode on T6SS by pH in FS14 is different from previously reported in other bacteria. Therefore, our results suggest a novel pH regulation mode of T6SS in S. marcesens FS14, and would broaden our knowledge on the regulation of T6SS secretion.
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Affiliation(s)
- Fengyu Jia
- Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, China
| | - Xuede Peng
- Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, China
| | - Xiaomei Yang
- Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, China
| | - Shenshen Qiu
- Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, China
| | - Shanshan Jia
- Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, China
| | - Tingting Ran
- Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, China
| | - Weiwu Wang
- Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, China
| | - Dongqing Xu
- Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, China
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10
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Maphosa S, Moleleki LN. A computational and secretome analysis approach reveals exclusive and shared candidate type six secretion system substrates in Pectobacterium brasiliense 1692. Microbiol Res 2024; 278:127501. [PMID: 37976736 DOI: 10.1016/j.micres.2023.127501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 08/24/2023] [Accepted: 09/13/2023] [Indexed: 11/19/2023]
Abstract
The type 6 secretion system (T6SS) of Gram-negative bacteria (GNB) has implications for bacterial competition, virulence, and survival. For the broad host range pathogen, Pectobacterium brasiliense 1692, T6SS-mediated competition occurs in a tissue-specific manner. However, no other roles have been investigated. The aim of this study was to identify T6SS-associated proteins under virulence inducing conditions. We used Bastion tools to predict 1479 Pbr1692 secreted proteins. Sixteen percent of these overlap between type 1-4 secretion systems (T1SS-T4SS) and T6SS. Using label-free quantitative mass spectrometry of Pbr1692 T6SS active and T6SS inactive strains' secretomes cultured in minimal media supplemented with host extract, 49 T6SS-associated proteins with varied gene ontology predicted functions were identified. We report 19 and 30 T6SS primary substrates and differentially secreted proteins, respectively, in T6SS mutants versus wild type strains. Of the total 49 T6SS-associated proteins presented in this study, 25 were also predicted using the BastionX platform as T6SS exclusive and shared substrates with T1SS-T4SS. This work provides a list of Pbr1692 T6SS secreted effector candidates. These include a potential antibacterial toxin HNH endonuclease and several predicted virulence proteins, including plant cell wall degrading enzymes. A preliminary basis for potential crosstalk between GNB secretion systems is also highlighted.
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Affiliation(s)
- S Maphosa
- Department of Biochemistry, Genetics, and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Hatfield, Pretoria, South Africa.
| | - L N Moleleki
- Department of Biochemistry, Genetics, and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Hatfield, Pretoria, South Africa
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11
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Anderson AJG, Morrell B, Lopez Campos G, Valvano MA. Distribution and diversity of type VI secretion system clusters in Enterobacter bugandensis and Enterobacter cloacae. Microb Genom 2023; 9:001148. [PMID: 38054968 PMCID: PMC10763514 DOI: 10.1099/mgen.0.001148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 11/16/2023] [Indexed: 12/07/2023] Open
Abstract
Gram-negative bacteria use type VI secretion systems (T6SSs) to antagonize neighbouring cells. Although primarily involved in bacterial competition, the T6SS is also implicated in pathogenesis, biofilm formation and ion scavenging. Enterobacter species belong to the ESKAPE pathogens, and while their antibiotic resistance has been well studied, less is known about their pathogenesis. Here, we investigated the distribution and diversity of T6SS components in isolates of two clinically relevant Enterobacter species, E. cloacae and E. bugandensis. T6SS clusters are grouped into four types (T6SSi-T6SSiv), of which type i can be further divided into six subtypes (i1, i2, i3, i4a, i4b, i5). Analysis of a curated dataset of 31 strains demonstrated that most of them encode T6SS clusters belonging to the T6SSi type. All T6SS-positive strains possessed a conserved i3 cluster, and many harboured one or two additional i2 clusters. These clusters were less conserved, and some strains displayed evidence of deletion. We focused on a pathogenic E. bugandensis clinical isolate for comprehensive in silico effector prediction, with comparative analyses across the 31 isolates. Several new effector candidates were identified, including an evolved VgrG with a metallopeptidase domain and a Tse6-like protein. Additional effectors included an anti-eukaryotic catalase (KatN), M23 peptidase, PAAR and VgrG proteins. Our findings highlight the diversity of Enterobacter T6SSs and reveal new putative effectors that may be important for the interaction of these species with neighbouring cells and their environment.
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Affiliation(s)
- Amy J. G. Anderson
- Wellcome-Wolfson Institute for Experimental Medicine, Queen’s University Belfast, Belfast, BT9 7BL, UK
| | - Becca Morrell
- Wellcome-Wolfson Institute for Experimental Medicine, Queen’s University Belfast, Belfast, BT9 7BL, UK
| | - Guillermo Lopez Campos
- Wellcome-Wolfson Institute for Experimental Medicine, Queen’s University Belfast, Belfast, BT9 7BL, UK
| | - Miguel A. Valvano
- Wellcome-Wolfson Institute for Experimental Medicine, Queen’s University Belfast, Belfast, BT9 7BL, UK
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12
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Smith JA, Holmes DE, Woodard TL, Li Y, Liu X, Wang LY, Meier D, Schwarz IA, Lovley DR. Detrimental impact of the Geobacter metallireducens type VI secretion system on direct interspecies electron transfer. Microbiol Spectr 2023; 11:e0094123. [PMID: 37650614 PMCID: PMC10580878 DOI: 10.1128/spectrum.00941-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 07/02/2023] [Indexed: 09/01/2023] Open
Abstract
Direct interspecies electron transfer (DIET) is important in anaerobic communities of environmental and practical significance. Other than the need for close physical contact for electrical connections, the interactions of DIET partners are poorly understood. Type VI secretion systems (T6SSs) typically kill competitive microbes. Surprisingly, Geobacter metallireducens highly expressed T6SS genes when DIET-based co-cultures were initiated with Geobacter sulfurreducens. T6SS gene expression was lower when the electron shuttle anthraquinone-2,6-disulfonate was added to alleviate the need for interspecies contact. Disruption of hcp, the G. metallireducens gene for the main T6SS needle-tube protein subunit, and the most highly upregulated gene in DIET-grown cells eliminated the long lag periods required for the initiation of DIET. The mutation did not aid DIET in the presence of granular-activated carbon (GAC), consistent with the fact that DIET partners do not make physical contact when electrically connected through conductive materials. The hcp-deficient mutant also established DIET quicker with Methanosarcina barkeri. However, the mutant also reduced Fe(III) oxide faster than the wild-type strain, a phenotype not expected from the loss of the T6SS. Quantitative PCR revealed greater gene transcript abundance for key components of extracellular electron transfer in the hcp-deficient mutant versus the wild-type strain, potentially accounting for the faster Fe(III) oxide reduction and impact on DIET. The results highlight that interspecies interactions beyond electrical connections may influence DIET effectiveness. The unexpected increase in the expression of genes for extracellular electron transport components when hcp was deleted emphasizes the complexities in evaluating the electromicrobiology of highly adaptable Geobacter species. IMPORTANCE Direct interspecies electron transfer is an alternative to the much more intensively studied process of interspecies H2 transfer as a mechanism for microbes to share electrons during the cooperative metabolism of energy sources. DIET is an important process in anaerobic soils and sediments generating methane, a significant greenhouse gas. Facilitating DIET can accelerate and stabilize the conversion of organic wastes to methane biofuel in anaerobic digesters. Therefore, a better understanding of the factors controlling how fast DIET partnerships are established is expected to lead to new strategies for promoting this bioenergy process. The finding that when co-cultured with G. sulfurreducens, G. metallireducens initially expressed a type VI secretion system, a behavior not conducive to interspecies cooperation, illustrates the complexity of establishing syntrophic relationships.
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Affiliation(s)
- Jessica A. Smith
- Department of Microbiology, University of Massachusetts Amherst, Morrill IV N Science Center, Amherst, Massachusetts, USA
- Department of Biomolecular Sciences, Central Connecticut State University, New Britain, Connecticut, USA
| | - Dawn E. Holmes
- Department of Microbiology, University of Massachusetts Amherst, Morrill IV N Science Center, Amherst, Massachusetts, USA
- Department of Physical and Biological Sciences, Western New England University, Springfield, Massachusetts, USA
| | - Trevor L. Woodard
- Department of Microbiology, University of Massachusetts Amherst, Morrill IV N Science Center, Amherst, Massachusetts, USA
| | - Yang Li
- Department of Microbiology, University of Massachusetts Amherst, Morrill IV N Science Center, Amherst, Massachusetts, USA
- School of Ocean Science and Technology, Dalian University of Technology, Panjin, Liaoning, China
| | - Xinying Liu
- Department of Microbiology, University of Massachusetts Amherst, Morrill IV N Science Center, Amherst, Massachusetts, USA
- College of Environmental Science and Engineering, Beijing Forestry University, Beijing, China
| | - Li-Ying Wang
- Department of Microbiology, University of Massachusetts Amherst, Morrill IV N Science Center, Amherst, Massachusetts, USA
| | - David Meier
- Department of Microbiology, University of Massachusetts Amherst, Morrill IV N Science Center, Amherst, Massachusetts, USA
| | - Ingrid A. Schwarz
- Department of Biomolecular Sciences, Central Connecticut State University, New Britain, Connecticut, USA
| | - Derek R. Lovley
- Department of Microbiology, University of Massachusetts Amherst, Morrill IV N Science Center, Amherst, Massachusetts, USA
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13
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Scheller D, Becker F, Wimbert A, Meggers D, Pienkoß S, Twittenhoff C, Knoke LR, Leichert LI, Narberhaus F. The oxidative stress response, in particular the katY gene, is temperature-regulated in Yersinia pseudotuberculosis. PLoS Genet 2023; 19:e1010669. [PMID: 37428814 PMCID: PMC10358904 DOI: 10.1371/journal.pgen.1010669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 06/12/2023] [Indexed: 07/12/2023] Open
Abstract
Pathogenic bacteria, such as Yersinia pseudotuberculosis encounter reactive oxygen species (ROS) as one of the first lines of defense in the mammalian host. In return, the bacteria react by mounting an oxidative stress response. Previous global RNA structure probing studies provided evidence for temperature-modulated RNA structures in the 5'-untranslated region (5'-UTR) of various oxidative stress response transcripts, suggesting that opening of these RNA thermometer (RNAT) structures at host-body temperature relieves translational repression. Here, we systematically analyzed the transcriptional and translational regulation of ROS defense genes by RNA-sequencing, qRT-PCR, translational reporter gene fusions, enzymatic RNA structure probing and toeprinting assays. Transcription of four ROS defense genes was upregulated at 37°C. The trxA gene is transcribed into two mRNA isoforms, of which the most abundant short one contains a functional RNAT. Biochemical assays validated temperature-responsive RNAT-like structures in the 5'-UTRs of sodB, sodC and katA. However, they barely conferred translational repression in Y. pseudotuberculosis at 25°C suggesting partially open structures available to the ribosome in the living cell. Around the translation initiation region of katY we discovered a novel, highly efficient RNAT that was primarily responsible for massive induction of KatY at 37°C. By phenotypic characterization of catalase mutants and through fluorometric real-time measurements of the redox-sensitive roGFP2-Orp1 reporter in these strains, we revealed KatA as the primary H2O2 scavenger. Consistent with the upregulation of katY, we observed an improved protection of Y. pseudotuberculosis at 37°C. Our findings suggest a multilayered regulation of the oxidative stress response in Yersinia and an important role of RNAT-controlled katY expression at host body temperature.
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Affiliation(s)
- Daniel Scheller
- Ruhr University Bochum, Faculty of Biology and Biotechnology, Microbial Biology, Bochum, Germany
| | - Franziska Becker
- Ruhr University Bochum, Faculty of Biology and Biotechnology, Microbial Biology, Bochum, Germany
| | - Andrea Wimbert
- Ruhr University Bochum, Faculty of Biology and Biotechnology, Microbial Biology, Bochum, Germany
| | - Dominik Meggers
- Ruhr University Bochum, Faculty of Biology and Biotechnology, Microbial Biology, Bochum, Germany
| | - Stephan Pienkoß
- Ruhr University Bochum, Faculty of Biology and Biotechnology, Microbial Biology, Bochum, Germany
| | - Christian Twittenhoff
- Ruhr University Bochum, Faculty of Biology and Biotechnology, Microbial Biology, Bochum, Germany
| | - Lisa R Knoke
- Ruhr University Bochum, Faculty of Medicine, Institute of Biochemistry and Pathobiochemistry, Microbial Biochemistry, Bochum, Germany
| | - Lars I Leichert
- Ruhr University Bochum, Faculty of Medicine, Institute of Biochemistry and Pathobiochemistry, Microbial Biochemistry, Bochum, Germany
| | - Franz Narberhaus
- Ruhr University Bochum, Faculty of Biology and Biotechnology, Microbial Biology, Bochum, Germany
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14
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Prince A, Wong Fok Lung T. Immunometabolic control by Klebsiella pneumoniae. IMMUNOMETABOLISM (COBHAM, SURREY) 2023; 5:e00028. [PMID: 37492184 PMCID: PMC10364963 DOI: 10.1097/in9.0000000000000028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Accepted: 06/27/2023] [Indexed: 07/27/2023]
Abstract
Klebsiella pneumoniae is a common Gram-negative pathogen associated with community-acquired and healthcare-associated infections. Its ability to acquire genetic elements resulted in its rapid development of resistance to virtually all antimicrobial agents. Once infection is established, K. pneumoniae is able to evade the host immune response and perhaps more importantly, undergo metabolic rewiring to optimize its ability to maintain infection. K. pneumoniae lipopolysaccharide and capsular polysaccharide are central factors in the induction and evasion of immune clearance. Less well understood is the importance of immunometabolism, the intersection between cellular metabolism and immune function, in the host response to K. pneumoniae infection. Bacterial metabolism itself is perceived as a metabolic stress to the host, altering the microenvironment at the site of infection. In this review, we will discuss the metabolic responses induced by K. pneumoniae, particularly in response to stimulation with the metabolically active bacteria versus pathogen-associated molecular patterns alone, and their implications in shaping the nature of the immune response and the infection outcome. A better understanding of the immunometabolic response to K. pneumoniae may help identify new targets for therapeutic intervention in the treatment of multidrug-resistant bacterial infections.
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Affiliation(s)
- Alice Prince
- Department of Pediatrics, Columbia University, New York, NY, USA
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15
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Song H, Yang B, Kang Y, Cong W. Critical roles of VipB protein on virulence and oxidative stress tolerance in Aeromonas veronii. JOURNAL OF FISH DISEASES 2023; 46:487-497. [PMID: 36708291 DOI: 10.1111/jfd.13760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 01/01/2023] [Accepted: 01/10/2023] [Indexed: 06/18/2023]
Abstract
Aeromonas veronii is a zoonotic pathogen capable of causing sepsis and ulceration in freshwater fish. Recently, reports of numerous cases indicate a marked increase in pathogenicity. Nonetheless, little is known about the pathogenesis of A. veronii infections. In this study, an in-frame mutant of the A. veronii vipB gene was generated to investigate its biological function. Deletion of the vipB gene resulted in a significant 204.71-fold decrease in the LD50 of A. veronii against zebrafish and a 2-fold and 4-fold reduction in the toxicity to EPC cells at 1 h and 2 h of infection, respectively. The virulence-related genes of the mutant ΔvipB all showed significantly reduced expression levels compared to the wild strain. In addition, the motility of the mutant ΔvipB decreased significantly, the adhesion ability to EPC cells was 3.25-fold lower than that of the parental strain, and the oxidative stress tolerance was 2.31-fold lower than that of TH0426 strain. In contrast, the biofilm formation amount of ΔvipB strain increased by 1.65-fold at both 12 h and 24 h. Our findings suggest that the vipB gene is associated with flagella stability, virulence, and oxidative stress tolerance and plays critical roles in the pathogenesis of A. veronii infections.
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Affiliation(s)
- Haichao Song
- Marine College, Shandong University, Weihai, China
| | - Bintong Yang
- Marine College, Shandong University, Weihai, China
| | | | - Wei Cong
- Marine College, Shandong University, Weihai, China
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16
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Singh RP, Kumari K. Bacterial type VI secretion system (T6SS): an evolved molecular weapon with diverse functionality. Biotechnol Lett 2023; 45:309-331. [PMID: 36683130 DOI: 10.1007/s10529-023-03354-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 12/14/2022] [Accepted: 01/05/2023] [Indexed: 01/24/2023]
Abstract
Bacterial secretion systems are nanomolecular complexes that release a diverse set of virulence factors/or proteins into its surrounding or translocate to their target host cells. Among these systems, type VI secretion system 'T6SS' is a recently discovered molecular secretion system which is widely distributed in Gram-negative (-ve) bacteria, and shares structural similarity with the puncturing device of bacteriophages. The presence of T6SS is an advantage to many bacteria as it delivers toxins to its neighbour pathogens for competitive survival, and also translocates protein effectors to the host cells, leading to disruption of lipid membranes, cell walls, and cytoskeletons etc. Recent studies have characterized both anti-prokaryotic and anti-eukaryotic effectors, where T6SS is involved in diverse cellular functions including favouring colonization, enhancing the survival, adhesive modifications, internalization, and evasion of the immune system. With the evolution of advanced genomics and proteomics tools, there has been an increase in the number of characterized T6SS effector arsenals and also more clear information about the adaptive significance of this complex system. The functions of T6SS are generally regulated at the transcription, post-transcription and post-translational levels through diverse mechanisms. In the present review, we aimed to provide information about the distribution of T6SS in diverse bacteria, any structural similarity/or dissimilarity, effectors proteins, functional significance, and regulatory mechanisms. We also tried to provide information about the diverse roles played by T6SS in its natural environments and hosts, and further any changes in the microbiome.
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Affiliation(s)
- Rajnish Prakash Singh
- Department of Bioengineering and Biotechnology, Birla Institute of Technology, Mesra, Ranchi, Jharkhand, 835215, India.
| | - Kiran Kumari
- Department of Bioengineering and Biotechnology, Birla Institute of Technology, Mesra, Ranchi, Jharkhand, 835215, India
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17
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Melchior K, Salgaço MK, Sivieri K, Moreira CG. QseC sensor kinase modulates the human microbiota during enterohemorrhagic Escherichia coli O157:H7 infection in the Simulator of the Human Intestinal Microbial Ecosystem (SHIME®). Braz J Microbiol 2023; 54:1-14. [PMID: 36469301 PMCID: PMC9943815 DOI: 10.1007/s42770-022-00877-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 11/08/2022] [Indexed: 12/11/2022] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) is an important gastrointestinal pathogen known for its ability to cause hemorrhagic colitis and induce hemolytic-uremic syndrome. The inner membrane QseC histidine kinase sensor has shown to be an important regulator of the locus of enterocyte effacement (LEE) island, where important EHEC key virulence genes are located. However, the QseC role during EHEC infection in human microbiota remains unknown. Herein, using the Simulator of the Human Intestinal Microbial Ecosystem (SHIME®), we investigated whether the QseC sensor has a role in human microbiota modulation by EHEC in a dynamic model. Our data demonstrated that the QseC sensor modulates human microbiota during EHEC infection, and its absence leads to an increase in Lactobacillaceae and Bifidobacterium genus predominance, although non-effect on Bacteroides genus by EHEC strains was observed. In co-culture, the Lactobacillus acidophilus has affected EHEC growth and impaired the EHEC growth under space-niche competition, although no growth difference was observed in the QseC sensor presence. Also, differences in EHEC growth were not detected in competition with Bacteroides thetaiotaomicron and EHEC strains did not affect B. thetaiotaomicron growth either. When investigating the mechanisms behind the SHIME results, we found that hcp-2 expression for the type 6 secretion system, known to be involved in bacterial competition, is under QseC sensor regulation beneath different environmental signals, such as glucose and butyrate. Our findings broaden the knowledge about the QseC sensor in modulating the human microbiota and its importance for EHEC pathogenesis.
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Affiliation(s)
- Karine Melchior
- Department of Biological Sciences, School of Pharmaceutical Sciences, São Paulo State University (UNESP), Araraquara, Brazil
| | - Mateus Kawata Salgaço
- Department of Food and Nutrition, School of Pharmaceutical Sciences, State University of São Paulo (UNESP), Araraquara, SP, Brazil
| | - Katia Sivieri
- Department of Food and Nutrition, School of Pharmaceutical Sciences, State University of São Paulo (UNESP), Araraquara, SP, Brazil
| | - Cristiano Gallina Moreira
- Department of Biological Sciences, School of Pharmaceutical Sciences, São Paulo State University (UNESP), Araraquara, Brazil.
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18
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Čapek J, Večerek B. Why is manganese so valuable to bacterial pathogens? Front Cell Infect Microbiol 2023; 13:943390. [PMID: 36816586 PMCID: PMC9936198 DOI: 10.3389/fcimb.2023.943390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 01/04/2023] [Indexed: 02/05/2023] Open
Abstract
Apart from oxygenic photosynthesis, the extent of manganese utilization in bacteria varies from species to species and also appears to depend on external conditions. This observation is in striking contrast to iron, which is similar to manganese but essential for the vast majority of bacteria. To adequately explain the role of manganese in pathogens, we first present in this review that the accumulation of molecular oxygen in the Earth's atmosphere was a key event that linked manganese utilization to iron utilization and put pressure on the use of manganese in general. We devote a large part of our contribution to explanation of how molecular oxygen interferes with iron so that it enhances oxidative stress in cells, and how bacteria have learned to control the concentration of free iron in the cytosol. The functioning of iron in the presence of molecular oxygen serves as a springboard for a fundamental understanding of why manganese is so valued by bacterial pathogens. The bulk of this review addresses how manganese can replace iron in enzymes. Redox-active enzymes must cope with the higher redox potential of manganese compared to iron. Therefore, specific manganese-dependent isoenzymes have evolved that either lower the redox potential of the bound metal or use a stronger oxidant. In contrast, redox-inactive enzymes can exchange the metal directly within the individual active site, so no isoenzymes are required. It appears that in the physiological context, only redox-inactive mononuclear or dinuclear enzymes are capable of replacing iron with manganese within the same active site. In both cases, cytosolic conditions play an important role in the selection of the metal used. In conclusion, we summarize both well-characterized and less-studied mechanisms of the tug-of-war for manganese between host and pathogen.
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Affiliation(s)
- Jan Čapek
- *Correspondence: Jan Čapek, ; Branislav Večerek,
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19
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Pseudomonas aeruginosa H3-T6SS Combats H 2O 2 Stress by Diminishing the Amount of Intracellular Unincorporated Iron in a Dps-Dependent Manner and Inhibiting the Synthesis of PQS. Int J Mol Sci 2023; 24:ijms24021614. [PMID: 36675127 PMCID: PMC9866239 DOI: 10.3390/ijms24021614] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 12/28/2022] [Accepted: 01/10/2023] [Indexed: 01/17/2023] Open
Abstract
The type VI secretion system (T6SS), a protein translocation nanomachine, is widely distributed in Gram-negative bacteria and delivers effectors directly into target cells or the extracellular environment to help the bacteria gain a competitive fitness advantage and promote bacterial survival in harmful environments. In this study, we demonstrated that the synthesis of the Pseudomonas quinolone signal (PQS) in Pseudomonas aeruginosa PAO1 was inhibited by the H3-T6SS gene cluster under iron-rich conditions, and that this inhibition was relieved under iron starvation conditions. Conversely, PQS differentially regulated the expression of the H3-T6SS structural genes and the effector protein gene tseF. The expression of tseF was inhibited by PQS, while the expressions of the H3-T6SS structural genes were positively regulated by PQS. Further studies showed that the H3-T6SS was involved in the resistance of P. aeruginosa to oxidative stress caused by hydrogen peroxide (H2O2). Interestingly, H3-T6SS expression was neither induced by H2O2 stress nor regulated by OxyR (a global anti-oxidative transcriptional regulator) but was positively regulated by RpoS (a major transcription regulator of the stress response). In addition, we found that the clpV3 (a structural gene of H3-T6SS) mutation resulted in upregulation of two proteins related to PQS synthesis and many proteins related to oxidative stress resistance, while the expression of some iron storage proteins, especially Dps, were significantly downregulated. Furthermore, the clpV3 mutation led to an increase in the intracellular free Fe2+ content of P. aeruginosa. Further studies showed that both the PQS deficient mutation and overexpression of dps effectively restored the H2O2 sensitive phenotype of the H3-T6SS mutant. Finally, we proposed the following model of H3-T6SS-mediated resistance to H2O2 stress in P. aeruginosa. H3-T6SS not only reduces the intracellular free Fe2+ level by upregulating the expression of ferritin Dps, but also inhibits the synthesis of PQS to mediate the resistance of P. aeruginosa to H2O2 stress. This study highlights the important role of H3-T6SS in the ability of P. aeruginosa to combat H2O2 stress and provides a perspective for understanding the stress response mechanism of bacteria.
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20
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Gabbert AD, Mydosh JL, Talukdar PK, Gloss LM, McDermott JE, Cooper KK, Clair GC, Konkel ME. The Missing Pieces: The Role of Secretion Systems in Campylobacter jejuni Virulence. Biomolecules 2023; 13:135. [PMID: 36671522 PMCID: PMC9856085 DOI: 10.3390/biom13010135] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 12/29/2022] [Accepted: 01/05/2023] [Indexed: 01/10/2023] Open
Abstract
Campylobacter jejuni is likely the most common bacterial cause of gastroenteritis worldwide, responsible for millions of cases of inflammatory diarrhea characterized by severe abdominal cramps and blood in the stool. Further, C. jejuni infections are associated with post-infection sequelae in developed countries and malnutrition and growth-stunting in low- and middle-income countries. Despite the increasing prevalence of the disease, campylobacteriosis, and the recognition that this pathogen is a serious health threat, our understanding of C. jejuni pathogenesis remains incomplete. In this review, we focus on the Campylobacter secretion systems proposed to contribute to host-cell interactions and survival in the host. Moreover, we have applied a genomics approach to defining the structural and mechanistic features of C. jejuni type III, IV, and VI secretion systems. Special attention is focused on the flagellar type III secretion system and the prediction of putative effectors, given that the proteins exported via this system are essential for host cell invasion and the inflammatory response. We conclude that C. jejuni does not possess a type IV secretion system and relies on the type III and type VI secretion systems to establish a niche and potentiate disease.
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Affiliation(s)
- Amber D. Gabbert
- School of Molecular Biosciences, College of Veterinary Sciences, Washington State University, Pullman, WA 99164, USA
| | - Jennifer L. Mydosh
- School of Animal and Comparative Biomedical Sciences, The University of Arizona, Tucson, AZ 85721, USA
| | - Prabhat K. Talukdar
- School of Molecular Biosciences, College of Veterinary Sciences, Washington State University, Pullman, WA 99164, USA
| | - Lisa M. Gloss
- School of Molecular Biosciences, College of Veterinary Sciences, Washington State University, Pullman, WA 99164, USA
| | - Jason E. McDermott
- Integrative Omics, Pacific Northwest National Laboratory, Richland, WA 99354, USA
| | - Kerry K. Cooper
- School of Animal and Comparative Biomedical Sciences, The University of Arizona, Tucson, AZ 85721, USA
| | - Geremy C. Clair
- Integrative Omics, Pacific Northwest National Laboratory, Richland, WA 99354, USA
| | - Michael E. Konkel
- School of Molecular Biosciences, College of Veterinary Sciences, Washington State University, Pullman, WA 99164, USA
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21
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Harishankar A, Viswanathan V. Attaching and effacing pathogens modulate host mitochondrial structure and function. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2023. [DOI: 10.1016/bs.ircmb.2023.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
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22
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Kim SK, Lee JB, Yoon JW. Characterization of transcriptional activities at a divergent promoter of the type VI secretion system in enterohemorrhagic Escherichia coli O157:H7. J Microbiol 2022; 60:928-934. [DOI: 10.1007/s12275-022-2109-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 05/16/2022] [Accepted: 05/30/2022] [Indexed: 10/15/2022]
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23
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Tantoso E, Eisenhaber B, Kirsch M, Shitov V, Zhao Z, Eisenhaber F. To kill or to be killed: pangenome analysis of Escherichia coli strains reveals a tailocin specific for pandemic ST131. BMC Biol 2022; 20:146. [PMID: 35710371 PMCID: PMC9205054 DOI: 10.1186/s12915-022-01347-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 06/08/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Escherichia coli (E. coli) has been one of the most studied model organisms in the history of life sciences. Initially thought just to be commensal bacteria, E. coli has shown wide phenotypic diversity including pathogenic isolates with great relevance to public health. Though pangenome analysis has been attempted several times, there is no systematic functional characterization of the E. coli subgroups according to the gene profile. RESULTS Systematically scanning for optimal parametrization, we have built the E. coli pangenome from 1324 complete genomes. The pangenome size is estimated to be ~25,000 gene families (GFs). Whereas the core genome diminishes as more genomes are added, the softcore genome (≥95% of strains) is stable with ~3000 GFs regardless of the total number of genomes. Apparently, the softcore genome (with a 92% or 95% generation threshold) can define the genome of a bacterial species listing the critically relevant, evolutionarily most conserved or important classes of GFs. Unsupervised clustering of common E. coli sequence types using the presence/absence GF matrix reveals distinct characteristics of E. coli phylogroups B1, B2, and E. We highlight the bi-lineage nature of B1, the variation of the secretion and of the iron acquisition systems in ST11 (E), and the incorporation of a highly conserved prophage into the genome of ST131 (B2). The tail structure of the prophage is evolutionarily related to R2-pyocin (a tailocin) from Pseudomonas aeruginosa PAO1. We hypothesize that this molecular machinery is highly likely to play an important role in protecting its own colonies; thus, contributing towards the rapid rise of pandemic E. coli ST131. CONCLUSIONS This study has explored the optimized pangenome development in E. coli. We provide complete GF lists and the pangenome matrix as supplementary data for further studies. We identified biological characteristics of different E. coli subtypes, specifically for phylogroups B1, B2, and E. We found an operon-like genome region coding for a tailocin specific for ST131 strains. The latter is a potential killer weapon providing pandemic E. coli ST131 with an advantage in inter-bacterial competition and, suggestively, explains their dominance as human pathogen among E. coli strains.
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Affiliation(s)
- Erwin Tantoso
- Genome Institute of Singapore (GIS), Agency for Science, Technology and Research (A*STAR), 60 Biopolis Street, Singapore, 138672, Republic of Singapore.,Bioinformatics Institute (BII), Agency for Science, Technology and Research (A*STAR), 30 Biopolis Street #07-01, Matrix Building, Singapore, 138671, Republic of Singapore
| | - Birgit Eisenhaber
- Genome Institute of Singapore (GIS), Agency for Science, Technology and Research (A*STAR), 60 Biopolis Street, Singapore, 138672, Republic of Singapore.,Bioinformatics Institute (BII), Agency for Science, Technology and Research (A*STAR), 30 Biopolis Street #07-01, Matrix Building, Singapore, 138671, Republic of Singapore
| | - Miles Kirsch
- Bioinformatics Institute (BII), Agency for Science, Technology and Research (A*STAR), 30 Biopolis Street #07-01, Matrix Building, Singapore, 138671, Republic of Singapore.,Present address: Northeastern University, Boston, USA
| | - Vladimir Shitov
- Bioinformatics Institute (BII), Agency for Science, Technology and Research (A*STAR), 30 Biopolis Street #07-01, Matrix Building, Singapore, 138671, Republic of Singapore
| | - Zhiya Zhao
- Bioinformatics Institute (BII), Agency for Science, Technology and Research (A*STAR), 30 Biopolis Street #07-01, Matrix Building, Singapore, 138671, Republic of Singapore.,Present address: The University of Cambridge, Cambridge, UK
| | - Frank Eisenhaber
- Genome Institute of Singapore (GIS), Agency for Science, Technology and Research (A*STAR), 60 Biopolis Street, Singapore, 138672, Republic of Singapore. .,Bioinformatics Institute (BII), Agency for Science, Technology and Research (A*STAR), 30 Biopolis Street #07-01, Matrix Building, Singapore, 138671, Republic of Singapore. .,School of Biological Sciences (SBS), Nanyang Technological University (NTU), 60 Nanyang Drive, 637551, Singapore, Republic of Singapore.
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24
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Sun Z, Zhou N, Zhang W, Xu Y, Yao YF. Dual role of CsrA in regulating the hemolytic activity of Escherichia coli O157:H7. Virulence 2022; 13:859-874. [PMID: 35609307 PMCID: PMC9132389 DOI: 10.1080/21505594.2022.2073023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Post-transcriptional global carbon storage regulator A (CsrA) is a sequence-specific RNA-binding protein involved in the regulation of multiple bacterial processes. Hemolysin is an important virulence factor in the enterohemorrhagic Escherichia coli O157:H7 (EHEC). Here, we show that CsrA plays a dual role in the regulation of hemolysis in EHEC. CsrA significantly represses plasmid-borne enterohemolysin (EhxA)-mediated hemolysis and activates chromosome-borne hemolysin E (HlyE)-mediated hemolysis through different mechanisms. RNA structure prediction revealed a well-matched stem-loop structure with two potential CsrA binding sites located on the 5' untranslated region (UTR) of ehxB, which encodes a translocator required for EhxA secretion. CsrA inhibits EhxA secretion by directly binding to the RNA leader sequence of ehxB to repress its expression in two different ways: CsrA either binds to the Shine–Dalgarno sequence of ehxB to block ribosome access or to ehxB transcript to promote its mRNA decay. The predicted CsrA-binding site 1 of ehxB is essential for its regulation. There is a single potential CsrA-binding site at the 5'-end of the hlyE transcript, and its mutation completely abolishes CsrA-dependent activation. CsrA can also stabilize hlyE mRNA by directly binding to its 5' UTR. Overall, our results indicate that CsrA acts as a hemolysis modulator to regulate pathogenicity under certain conditions.
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Affiliation(s)
- Zhibin Sun
- Laboratory of Bacterial Pathogenesis, Department of Microbiology and Immunology, Institutes of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Jiangsu Province Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Ning Zhou
- Laboratory of Bacterial Pathogenesis, Department of Microbiology and Immunology, Institutes of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Wenting Zhang
- Laboratory of Bacterial Pathogenesis, Department of Microbiology and Immunology, Institutes of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yan Xu
- Jiangsu Province Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Yu-Feng Yao
- Laboratory of Bacterial Pathogenesis, Department of Microbiology and Immunology, Institutes of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Department of Infectious Diseases, Shanghai Ruijin Hospital, Shanghai, China.,Shanghai Key Laboratory of Emergency Prevention, Diagnosis and Treatment of Respiratory Infectious Diseases, Shanghai, China
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25
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Wong Fok Lung T, Charytonowicz D, Beaumont KG, Shah SS, Sridhar SH, Gorrie CL, Mu A, Hofstaedter CE, Varisco D, McConville TH, Drikic M, Fowler B, Urso A, Shi W, Fucich D, Annavajhala MK, Khan IN, Oussenko I, Francoeur N, Smith ML, Stockwell BR, Lewis IA, Hachani A, Upadhyay Baskota S, Uhlemann AC, Ahn D, Ernst RK, Howden BP, Sebra R, Prince A. Klebsiella pneumoniae induces host metabolic stress that promotes tolerance to pulmonary infection. Cell Metab 2022; 34:761-774.e9. [PMID: 35413274 PMCID: PMC9081115 DOI: 10.1016/j.cmet.2022.03.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 01/18/2022] [Accepted: 03/22/2022] [Indexed: 12/21/2022]
Abstract
K. pneumoniae sequence type 258 (Kp ST258) is a major cause of healthcare-associated pneumonia. However, it remains unclear how it causes protracted courses of infection in spite of its expression of immunostimulatory lipopolysaccharide, which should activate a brisk inflammatory response and bacterial clearance. We predicted that the metabolic stress induced by the bacteria in the host cells shapes an immune response that tolerates infection. We combined in situ metabolic imaging and transcriptional analyses to demonstrate that Kp ST258 activates host glutaminolysis and fatty acid oxidation. This response creates an oxidant-rich microenvironment conducive to the accumulation of anti-inflammatory myeloid cells. In this setting, metabolically active Kp ST258 elicits a disease-tolerant immune response. The bacteria, in turn, adapt to airway oxidants by upregulating the type VI secretion system, which is highly conserved across ST258 strains worldwide. Thus, much of the global success of Kp ST258 in hospital settings can be explained by the metabolic activity provoked in the host that promotes disease tolerance.
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Affiliation(s)
| | - Daniel Charytonowicz
- Department of Genetics and Genomic Sciences, Mt. Sinai Icahn School of Medicine, New York, NY 10029, USA
| | - Kristin G Beaumont
- Department of Genetics and Genomic Sciences, Mt. Sinai Icahn School of Medicine, New York, NY 10029, USA
| | - Shivang S Shah
- Department of Pediatrics, Columbia University, New York, NY 10032, USA
| | - Shwetha H Sridhar
- Department of Genetics and Genomic Sciences, Mt. Sinai Icahn School of Medicine, New York, NY 10029, USA
| | - Claire L Gorrie
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia
| | - Andre Mu
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia
| | - Casey E Hofstaedter
- Department of Microbial Pathogenesis, University of Maryland, Baltimore, MD 21201, USA
| | - David Varisco
- Department of Microbial Pathogenesis, University of Maryland, Baltimore, MD 21201, USA
| | | | - Marija Drikic
- Department of Biological Sciences, University of Calgary, Calgary, T2N 1N4, Canada
| | - Brandon Fowler
- Microbiome & Pathogen Genomics Collaborative Center, Columbia University, New York, NY 10032, USA
| | - Andreacarola Urso
- Department of Pediatrics, Columbia University, New York, NY 10032, USA
| | - Wei Shi
- Department of Pediatrics, Columbia University, New York, NY 10032, USA
| | - Dario Fucich
- Department of Pediatrics, Columbia University, New York, NY 10032, USA
| | - Medini K Annavajhala
- Department of Medicine, Columbia University, New York, NY 10032, USA; Microbiome & Pathogen Genomics Collaborative Center, Columbia University, New York, NY 10032, USA
| | - Ibrahim N Khan
- Department of Pediatrics, Columbia University, New York, NY 10032, USA
| | - Irina Oussenko
- Department of Genetics and Genomic Sciences, Mt. Sinai Icahn School of Medicine, New York, NY 10029, USA
| | - Nancy Francoeur
- Department of Genetics and Genomic Sciences, Mt. Sinai Icahn School of Medicine, New York, NY 10029, USA
| | - Melissa L Smith
- Department of Genetics and Genomic Sciences, Mt. Sinai Icahn School of Medicine, New York, NY 10029, USA
| | - Brent R Stockwell
- Department of Chemistry, Columbia University, New York, NY 10027, USA; Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Ian A Lewis
- Department of Biological Sciences, University of Calgary, Calgary, T2N 1N4, Canada
| | - Abderrahman Hachani
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia
| | | | - Anne-Catrin Uhlemann
- Department of Medicine, Columbia University, New York, NY 10032, USA; Microbiome & Pathogen Genomics Collaborative Center, Columbia University, New York, NY 10032, USA
| | - Danielle Ahn
- Department of Pediatrics, Columbia University, New York, NY 10032, USA
| | - Robert K Ernst
- Department of Microbial Pathogenesis, University of Maryland, Baltimore, MD 21201, USA
| | - Benjamin P Howden
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia; Microbiological Diagnostic Unit Public Health Laboratory, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia
| | - Robert Sebra
- Department of Genetics and Genomic Sciences, Mt. Sinai Icahn School of Medicine, New York, NY 10029, USA; Sema4: A Mount Sinai Venture, Stamford, CT 06902, USA
| | - Alice Prince
- Department of Pediatrics, Columbia University, New York, NY 10032, USA.
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26
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Li K, Liao J, Wei M, Qiu S, Wu W, Zhao Y, Wang H, Liu Q, Liu F, Chang C. The Xanthomonas citri Reverse Fitness Deficiency by Activating a Novel β-Glucosidase Under Low Osmostress. Front Microbiol 2022; 13:887967. [PMID: 35586864 PMCID: PMC9108719 DOI: 10.3389/fmicb.2022.887967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 03/17/2022] [Indexed: 11/13/2022] Open
Abstract
Bacteria can withstand various types of environmental osmostress. A sudden rise in osmostress affects bacterial cell growth that is countered by activating special genes. The change of osmostress is generally a slow process under the natural environment. However, the collective response of bacteria to low osmostress remains unknown. This study revealed that the deletion of phoP (ΔphoP) from X. citri significantly compromised the growth and virulence as compared to the wild-type strain. Interestingly, low osmostress reversed physiological deficiencies of X. citri phoP mutant related to bacterial growth and virulence. The results also provided biochemical and genetic evidence that the physiological deficiency of phoP mutant can be reversed by low osmostress induced β-glucosidase (BglS) expression. Based on the data, this study proposes a novel regulatory mechanism of a novel β-glucosidase activation in X. citri through low osmostress to reverse the fitness deficiency.
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Affiliation(s)
- Kaihuai Li
- College of Plant Protection, Integrate Microbiology Research Center, South China Agricultural University, Guangzhou, China
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Jinxing Liao
- College of Plant Protection, Integrate Microbiology Research Center, South China Agricultural University, Guangzhou, China
| | - Ming Wei
- College of Plant Protection, Integrate Microbiology Research Center, South China Agricultural University, Guangzhou, China
| | - Shanxu Qiu
- College of Plant Protection, Integrate Microbiology Research Center, South China Agricultural University, Guangzhou, China
| | - Weiyin Wu
- College of Plant Protection, Integrate Microbiology Research Center, South China Agricultural University, Guangzhou, China
| | - Yancun Zhao
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Haihong Wang
- College of Life Sciences, South China Agricultural University, Guangzhou, China
| | - Qiongguang Liu
- College of Plant Protection, Integrate Microbiology Research Center, South China Agricultural University, Guangzhou, China
| | - Fengquan Liu
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
- *Correspondence: Fengquan Liu,
| | - Changqing Chang
- College of Plant Protection, Integrate Microbiology Research Center, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
- Changqing Chang,
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27
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Altayb HN, Elbadawi HS, Baothman O, Kazmi I, Alzahrani FA, Nadeem MS, Hosawi S, Chaieb K. Genomic Analysis of Multidrug-Resistant Hypervirulent (Hypermucoviscous) Klebsiella pneumoniae Strain Lacking the Hypermucoviscous Regulators (rmpA/rmpA2). Antibiotics (Basel) 2022; 11:antibiotics11050596. [PMID: 35625240 PMCID: PMC9137517 DOI: 10.3390/antibiotics11050596] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 04/23/2022] [Accepted: 04/26/2022] [Indexed: 12/28/2022] Open
Abstract
Hypervirulent K. pneumoniae (hvKP) strains possess distinct characteristics such as hypermucoviscosity, unique serotypes, and virulence factors associated with high pathogenicity. To better understand the genomic characteristics and virulence profile of the isolated hvKP strain, genomic data were compared to the genomes of the hypervirulent and typical K. pneumoniae strains. The K. pneumoniae strain was isolated from a patient with a recurrent urinary tract infection, and then the string test was used for the detection of the hypermucoviscosity phenotype. Whole-genome sequencing was conducted using Illumina, and bioinformatics analysis was performed for the prediction of the isolate resistome, virulome, and phylogenetic analysis. The isolate was identified as hypermucoviscous, type 2 (K2) capsular polysaccharide, ST14, and multidrug-resistant (MDR), showing resistance to ciprofloxacin, ceftazidime, cefotaxime, trimethoprim-sulfamethoxazole, cephalexin, and nitrofurantoin. The isolate possessed four antimicrobial resistance plasmids (pKPN3-307_type B, pECW602, pMDR, and p3K157) that carried antimicrobial resistance genes (ARGs) (blaOXA-1,blaCTX-M-15, sul2, APH(3″)-Ib, APH(6)-Id, and AAC(6′)-Ib-cr6). Moreover, two chromosomally mediated ARGs (fosA6 and SHV-28) were identified. Virulome prediction revealed the presence of 19 fimbrial proteins, one aerobactin (iutA) and two salmochelin (iroE and iroN). Four secretion systems (T6SS-I (13), T6SS-II (9), T6SS-III (12), and Sci-I T6SS (1)) were identified. Interestingly, the isolate lacked the known hypermucoviscous regulators (rmpA/rmpA2) but showed the presence of other RcsAB capsule regulators (rcsA and rcsB). This study documented the presence of a rare MDR hvKP with hypermucoviscous regulators and lacking the common capsule regulators, which needs more focus to highlight their epidemiological role.
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Affiliation(s)
- Hisham N. Altayb
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (O.B.); (I.K.); (F.A.A.); (M.S.N.); (S.H.); (K.C.)
- Centre for Artificial Intelligence in Precision Medicine, King Abdulaziz University, Jeddah 21589, Saudi Arabia
- Correspondence: ; Tel.: +0096-6549087515
| | - Hana S. Elbadawi
- Microbiology and Parasitology Department, Soba University Hospital, University of Khartoum, Khartoum 11115, Sudan;
| | - Othman Baothman
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (O.B.); (I.K.); (F.A.A.); (M.S.N.); (S.H.); (K.C.)
| | - Imran Kazmi
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (O.B.); (I.K.); (F.A.A.); (M.S.N.); (S.H.); (K.C.)
| | - Faisal A. Alzahrani
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (O.B.); (I.K.); (F.A.A.); (M.S.N.); (S.H.); (K.C.)
- Centre for Artificial Intelligence in Precision Medicine, King Abdulaziz University, Jeddah 21589, Saudi Arabia
- King Fahd Medical Research Center, Embryonic Stem Cells Unit, Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Muhammad Shahid Nadeem
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (O.B.); (I.K.); (F.A.A.); (M.S.N.); (S.H.); (K.C.)
| | - Salman Hosawi
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (O.B.); (I.K.); (F.A.A.); (M.S.N.); (S.H.); (K.C.)
- Centre for Artificial Intelligence in Precision Medicine, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Kamel Chaieb
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (O.B.); (I.K.); (F.A.A.); (M.S.N.); (S.H.); (K.C.)
- Laboratory of Analysis, Treatment and Valorization of Pollutants of the Environmental and Products, Faculty of Pharmacy, University of Monastir, Monastir 5000, Tunisia
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28
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Serapio-Palacios A, Woodward SE, Vogt SL, Deng W, Creus-Cuadros A, Huus KE, Cirstea M, Gerrie M, Barcik W, Yu H, Finlay BB. Type VI secretion systems of pathogenic and commensal bacteria mediate niche occupancy in the gut. Cell Rep 2022; 39:110731. [PMID: 35476983 DOI: 10.1016/j.celrep.2022.110731] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 02/04/2022] [Accepted: 04/01/2022] [Indexed: 12/18/2022] Open
Abstract
The type VI secretion system (T6SS) is a contractile nanomachine widely distributed among pathogenic and commensal Gram-negative bacteria. The T6SS is used for inter-bacterial competition to directly kill competing species; however, its importance during bacterial infection in vivo remains poorly understood. We report that the murine pathogen Citrobacter rodentium, used as a model for human pathogenic Escherichia coli, harbors two functional T6SSs. C. rodentium employs its T6SS-1 to colonize the murine gastrointestinal tract by targeting commensal Enterobacteriaceae. We identify VgrG1 as a C. rodentium T6SS antibacterial effector, which exhibits toxicity in E. coli. Conversely, commensal prey species E. coli Mt1B1 employs two T6SSs of its own to counter C. rodentium colonization. Collectively, these data demonstrate that the T6SS is a potent weapon during bacterial competition and is used by both invading pathogens and resident microbiota to fight for a niche in the hostile gut environment.
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Affiliation(s)
- Antonio Serapio-Palacios
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Department of Microbiology and Immunology, University of British Columbia, BC V6T 1Z3, Canada
| | - Sarah E Woodward
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Department of Microbiology and Immunology, University of British Columbia, BC V6T 1Z3, Canada
| | - Stefanie L Vogt
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Department of Microbiology and Immunology, University of British Columbia, BC V6T 1Z3, Canada
| | - Wanyin Deng
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Anna Creus-Cuadros
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Department of Microbiology and Immunology, University of British Columbia, BC V6T 1Z3, Canada
| | - Kelsey E Huus
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Department of Microbiology and Immunology, University of British Columbia, BC V6T 1Z3, Canada
| | - Mihai Cirstea
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Department of Microbiology and Immunology, University of British Columbia, BC V6T 1Z3, Canada
| | - Madeleine Gerrie
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Weronika Barcik
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Department of Microbiology and Immunology, University of British Columbia, BC V6T 1Z3, Canada
| | - Hongbing Yu
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - B Brett Finlay
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Department of Microbiology and Immunology, University of British Columbia, BC V6T 1Z3, Canada; Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
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29
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Nie H, Xiao Y, Song M, Wu N, Peng Q, Duan W, Chen W, Huang Q. Wsp system oppositely modulates antibacterial activity and biofilm formation via FleQ-FleN complex in Pseudomonas putida. Environ Microbiol 2022; 24:1543-1559. [PMID: 35178858 DOI: 10.1111/1462-2920.15905] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 01/13/2022] [Indexed: 11/29/2022]
Abstract
Type VI secretion systems (T6SS) are specific antibacterial weapons employed by diverse bacteria to protect themselves from competitors. Pseudomonas putida KT2440 possesses a functional T6SS (K1-T6SS) and exhibits antibacterial activity towards a broad range of bacteria. Here we found that the Wsp signal transduction system regulated K1-T6SS expression via synthesizing the second messenger cyclic di-GMP (c-di-GMP), thus mediating antibacterial activity in P. putida. High-level c-di-GMP produced by Wsp system repressed the transcription of K1-T6SS genes in structural operon and vgrG1 operon. Transcriptional regulator FleQ and ATPase FleN functioned as repressors in the Wsp system-modulated K1-T6SS transcription. However, FleQ and FleN functioned as activators in biofilm formation, and Wsp system promoted biofilm formation largely in a FleQ/FleN-dependent manner. Furthermore, FleQ-FleN complex bound directly to the promoter of K1-T6SS structural operon in vitro, and c-di-GMP promoted the binding. Besides, P. putida biofilm cells showed higher c-di-GMP levels and lower antibacterial activity than planktonic cells. Overall, our findings reveal a mechanism by which Wsp system oppositely modulates antibacterial activity and biofilm formation via FleQ-FleN, and demonstrate the relationship between plankton/biofilm lifestyles and antibacterial activity in P. putida.
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Affiliation(s)
- Hailing Nie
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yujie Xiao
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Miaomiao Song
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Nianqi Wu
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Qi Peng
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Wei Duan
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Wenli Chen
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Qiaoyun Huang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China.,Hubei Key Laboratory of Soil Environment and Pollution Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China
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30
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Yang X, Liu H, Zhang Y, Shen X. Roles of Type VI Secretion System in Transport of Metal Ions. Front Microbiol 2021; 12:756136. [PMID: 34803980 PMCID: PMC8602904 DOI: 10.3389/fmicb.2021.756136] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 10/12/2021] [Indexed: 11/18/2022] Open
Abstract
The type VI secretion system (T6SS) is a transmembrane protein nanomachine employed by many gram-negative bacteria to directly translocate effectors into adjacent cells or the extracellular milieu, showing multiple functions in both interbacterial competition and bacteria-host interactions. Metal ion transport is a newly discovered T6SS function. This review summarizes the identified T6SS functions and highlights the features of metal ion transport mediated by T6SS and discusses its regulation.
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Affiliation(s)
- Xiaobing Yang
- College of Applied Engineering, Henan University of Science and Technology (HAUST), Sanmenxia, China.,Medical College, Sanmenxia Vocational Technical School, Sanmenxia, China
| | - Hai Liu
- Qingyang Longfeng Sponge City Construction Management & Operation Co., Ltd, Qingyang, China
| | - Yanxiong Zhang
- Qingyang Longfeng Sponge City Construction Management & Operation Co., Ltd, Qingyang, China
| | - Xihui Shen
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Xianyang, China
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Identification of Two Variants of Acinetobacter baumannii Strain ATCC 17978 with Distinct Genotypes and Phenotypes. Infect Immun 2021; 89:e0045421. [PMID: 34460288 DOI: 10.1128/iai.00454-21] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Acinetobacter baumannii is a nosocomial pathogen that exhibits substantial genomic plasticity. Here, the identification of two variants of A. baumannii ATCC 17978 that differ based on the presence of a 44-kb accessory locus, named AbaAL44 (A. baumannii accessory locus 44 kb), is described. Analyses of existing deposited data suggest that both variants are found in published studies of A. baumannii ATCC 17978 and that American Type Culture Collection (ATCC)-derived laboratory stocks comprise a mix of these two variants. Yet, each variant exhibits distinct interactions with the host in vitro and in vivo. Infection with the variant that harbors AbaAL44 (A. baumannii 17978 UN) results in decreased bacterial burdens and increased neutrophilic lung inflammation in a mouse model of pneumonia, and affects the production of interleukin 1 beta (IL-1β) and IL-10 by infected macrophages. AbaAL44 harbors putative pathogenesis genes, including those predicted to encode a type I pilus cluster, a catalase, and a cardiolipin synthase. The accessory catalase increases A. baumannii resistance to oxidative stress and neutrophil-mediated killing in vitro. The accessory cardiolipin synthase plays a dichotomous role by promoting bacterial uptake and increasing IL-1β production by macrophages, but also by enhancing bacterial resistance to cell envelope stress. Collectively, these findings highlight the phenotypic consequences of the genomic dynamism of A. baumannii through the evolution of two variants of a common type strain with distinct infection-related attributes.
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Categorizing sequences of concern by function to better assess mechanisms of microbial pathogenesis. Infect Immun 2021; 90:e0033421. [PMID: 34780277 PMCID: PMC9119117 DOI: 10.1128/iai.00334-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
To identify sequences with a role in microbial pathogenesis, we assessed the adequacy of their annotation by existing controlled vocabularies and sequence databases. Our goal was to regularize descriptions of microbial pathogenesis for improved integration with bioinformatic applications. Here, we review the challenges of annotating sequences for pathogenic activity. We relate the categorization of more than 2,750 sequences of pathogenic microbes through a controlled vocabulary called Functions of Sequences of Concern (FunSoCs). These allow for an ease of description by both humans and machines. We provide a subset of 220 fully annotated sequences in the supplemental material as examples. The use of this compact (∼30 terms), controlled vocabulary has potential benefits for research in microbial genomics, public health, biosecurity, biosurveillance, and the characterization of new and emerging pathogens.
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Sauder AB, Kendall MM. A pathogen-specific sRNA influences enterohemorrhagic Escherichia coli fitness and virulence in part by direct interaction with the transcript encoding the ethanolamine utilization regulatory factor EutR. Nucleic Acids Res 2021; 49:10988-11004. [PMID: 34591974 PMCID: PMC8565329 DOI: 10.1093/nar/gkab863] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 09/09/2021] [Accepted: 09/14/2021] [Indexed: 01/07/2023] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) O157:H7 relies on sRNAs to coordinate expression of metabolic and virulence factors to colonize the host. Here, we focus on the sRNA, named MavR (metabolism and virulence regulator), that is conserved among pathogenic Enterobacteriaceae. MavR is constitutively expressed under in vitro conditions that promote EHEC virulence gene expression. Using MS2-affinity purification coupled with RNA sequencing, the eutR transcript was identified as a putative target of MavR. EutR is a transcription factor that promotes expression of genes required for ethanolamine metabolism as well as virulence factors important for host colonization. MavR binds to the eutR coding sequence to protect the eutR transcript from RNase E-mediated degradation. Ultimately, MavR promotes EutR expression and in turn ethanolamine utilization and ethanolamine-dependent growth. RNAseq analyses revealed that MavR also affected expression of genes important for other metabolic pathways, motility, oxidative stress and attaching and effacing lesion formation, which contribute to EHEC colonization of the gastrointestinal tract. In support of the idea that MavR-dependent gene expression affects fitness during infection, deletion of mavR resulted in significant (∼10- to 100-fold) attenuation in colonization of the mammalian intestine. Altogether, these studies reveal an important, extensive, and robust phenotype for a bacterial sRNA in host-pathogen interactions.
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Affiliation(s)
- Amber B Sauder
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Melissa M Kendall
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
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Lin J, Xu L, Yang J, Wang Z, Shen X. Beyond dueling: roles of the type VI secretion system in microbiome modulation, pathogenesis and stress resistance. STRESS BIOLOGY 2021; 1:11. [PMID: 37676535 PMCID: PMC10441901 DOI: 10.1007/s44154-021-00008-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Accepted: 08/09/2021] [Indexed: 09/08/2023]
Abstract
Bacteria inhabit diverse and dynamic environments, where nutrients may be limited and toxic chemicals can be prevalent. To adapt to these stressful conditions, bacteria have evolved specialized protein secretion systems, such as the type VI secretion system (T6SS) to facilitate their survival. As a molecular syringe, the T6SS expels various effectors into neighboring bacterial cells, eukaryotic cells, or the extracellular environment. These effectors improve the competitive fitness and environmental adaption of bacterial cells. Although primarily recognized as antibacterial weapons, recent studies have demonstrated that T6SSs have functions beyond interspecies competition. Here, we summarize recent research on the role of T6SSs in microbiome modulation, pathogenesis, and stress resistance.
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Affiliation(s)
- Jinshui Lin
- Shaanxi Key Laboratory of Chinese Jujube, College of Life Sciences, Yan'an University, Yan'an, Shaanxi, 716000, People's Republic of China
| | - Lei Xu
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, People's Republic of China
| | - Jianshe Yang
- Shaanxi Key Laboratory of Chinese Jujube, College of Life Sciences, Yan'an University, Yan'an, Shaanxi, 716000, People's Republic of China
| | - Zhuo Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, People's Republic of China
| | - Xihui Shen
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, People's Republic of China.
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Gu H, Cai X, Zhang X, Luo J, Zhang X, Hu X, Cai W, Li G. A previously uncharacterized two-component signaling system in uropathogenic Escherichia coli coordinates protection against host-derived oxidative stress with activation of hemolysin-mediated host cell pyroptosis. PLoS Pathog 2021; 17:e1010005. [PMID: 34653218 PMCID: PMC8550376 DOI: 10.1371/journal.ppat.1010005] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 10/27/2021] [Accepted: 10/04/2021] [Indexed: 12/22/2022] Open
Abstract
Uropathogenic Escherichia coli (UPEC) deploy an array of virulence factors to successfully establish urinary tract infections. Hemolysin is a pore-forming toxin, and its expression correlates with the severity of UPEC infection. Two-component signaling systems (TCSs) are a major mechanism by which bacteria sense environmental cues and respond by initiating adaptive responses. Here, we began this study by characterizing a novel TCS (C3564/C3565, herein renamed orhK/orhR for oxidative resistance and hemolysis kinase/regulator) that is encoded on a UPEC pathogenicity island, using bioinformatic and biochemical approaches. A prevalence analysis indicates that orhK/orhR is highly associated with the UPEC pathotype, and it rarely occurs in other E. coli pathotypes tested. We then demonstrated that OrhK/OrhR directly activates the expression of a putative methionine sulfoxide reductase system (C3566/C3567) and hemolysin (HlyA) in response to host-derived hydrogen peroxide (H2O2) exposure. OrhK/OrhR increases UPEC resistance to H2O2in vitro and survival in macrophages in cell culture via C3566/C3567. Additionally, OrhK/OrhR mediates hemolysin-induced renal epithelial cell and macrophage death via a pyroptosis pathway. Reducing intracellular H2O2 production by a chemical inhibitor impaired OrhK/OrhR-mediated activation of c3566-c3567 and hlyA. We also uncovered that UPEC links the two key virulence traits by cotranscribing the c3566-c3567 and hlyCABD operons. Taken together, our data suggest a paradigm in which a signal transduction system coordinates both bacterial pathogen defensive and offensive traits in the presence of host-derived signals; and this exquisite mechanism likely contributes to hemolysin-induced severe pathological outcomes. Uropathogenic Escherichia coli (UPEC) is the primary cause of urinary tract infections, and approximately half of UPEC isolates produce a pore-forming toxin, hemolysin. Clinically, hemolysin carriage is associated with severe pathology and symptoms during UPEC infections. However, overexpression of hemolysin can be detrimental to UPEC colonization. Therefore, fine-tuning of hemolysin expression in response to in vivo-relevant signals is critical for optimal UPEC fitness in the urinary tract. In this study, we describe a virulence strategy employed by UPEC, i.e., the bacteria use a two-component signaling (TCS) system to coordinate oxidative stress resistance and hemolysin-mediated pyroptosis of host cells in response to host-derived oxidative signals. The TCS achieves this coordination by cotranscribing genes encoding the oxidative stress resistance and the hemolysin. As a result, UPEC is able to link defense to offense, and this exquisite virulence mechanism likely contributes to UPEC fitness in vivo and hemolysin-induced severe pathological outcomes.
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Affiliation(s)
- Hongwei Gu
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America
- Central Laboratory, Nanjing Integrated Traditional Chinese and Western Medicine Hospital Affiliated with Nanjing University of Chinese Medicine, Nanjing, China
| | - Xuwang Cai
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Xinyang Zhang
- Key Laboratory of Veterinary Public Health of Ministry of Agriculture, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Jie Luo
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America
| | - Xiaoyang Zhang
- Central Laboratory, Nanjing Integrated Traditional Chinese and Western Medicine Hospital Affiliated with Nanjing University of Chinese Medicine, Nanjing, China
| | - Xiao Hu
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America
| | - Wentong Cai
- Key Laboratory of Veterinary Public Health of Ministry of Agriculture, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
- * E-mail: (WC); (GL)
| | - Ganwu Li
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America
- Key Laboratory of Veterinary Public Health of Ministry of Agriculture, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
- * E-mail: (WC); (GL)
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Defending against the Type Six Secretion System: beyond Immunity Genes. Cell Rep 2021; 33:108259. [PMID: 33053336 DOI: 10.1016/j.celrep.2020.108259] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 07/10/2020] [Accepted: 09/21/2020] [Indexed: 02/07/2023] Open
Abstract
The bacterial type six secretion system (T6SS) delivers toxic effector proteins into neighboring cells, but bacteria must protect themselves against their own T6SS. Immunity genes are the best-characterized defenses, protecting against specific cognate effectors. However, the prevalence of the T6SS and the coexistence of species with heterologous T6SSs suggest evolutionary pressure selecting for additional defenses against it. Here we review defenses against the T6SS beyond self-associated immunity genes, such as diverse stress responses that can recognize T6SS-inflicted damage and coordinate induction of molecular armor, repair pathways, and overall survival. Some of these stress responses are required for full survival even in the presence of immunity genes. Finally, we propose that immunity gene-independent protection is, mechanistically, bacterial innate immunity and that such defenses and the T6SS have co-evolved and continue to shape one another in polymicrobial communities.
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Gibson JF, Pidwill GR, Carnell OT, Surewaard BGJ, Shamarina D, Sutton JAF, Jeffery C, Derré-Bobillot A, Archambaud C, Siggins MK, Pollitt EJG, Johnston SA, Serror P, Sriskandan S, Renshaw SA, Foster SJ. Commensal bacteria augment Staphylococcus aureus infection by inactivation of phagocyte-derived reactive oxygen species. PLoS Pathog 2021; 17:e1009880. [PMID: 34529737 PMCID: PMC8478205 DOI: 10.1371/journal.ppat.1009880] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 09/28/2021] [Accepted: 08/09/2021] [Indexed: 12/22/2022] Open
Abstract
Staphylococcus aureus is a human commensal organism and opportunist pathogen, causing potentially fatal disease. The presence of non-pathogenic microflora or their components, at the point of infection, dramatically increases S. aureus pathogenicity, a process termed augmentation. Augmentation is associated with macrophage interaction but by a hitherto unknown mechanism. Here, we demonstrate a breadth of cross-kingdom microorganisms can augment S. aureus disease and that pathogenesis of Enterococcus faecalis can also be augmented. Co-administration of augmenting material also forms an efficacious vaccine model for S. aureus. In vitro, augmenting material protects S. aureus directly from reactive oxygen species (ROS), which correlates with in vivo studies where augmentation restores full virulence to the ROS-susceptible, attenuated mutant katA ahpC. At the cellular level, augmentation increases bacterial survival within macrophages via amelioration of ROS, leading to proliferation and escape. We have defined the molecular basis for augmentation that represents an important aspect of the initiation of infection. S. aureus is a commensal inhabitant of the human skin and nares. However, it can cause serious diseases if it is able to breach our protective barriers such as the skin, often via wounds or surgery. If infection occurs via a wound, this initial inoculum contains both the pathogen, other members of the microflora and also wider environmental microbes. We have previously described “augmentation”, whereby this other non-pathogenic material can enhance the ability of S. aureus to lead to a serious disease outcome. Here we have determined the breadth of augmenting material and elucidated the cellular and molecular basis for its activity. Augmentation occurs via shielding of S. aureus from the direct bactericidal effects of reactive oxygen species produced by macrophages. This initial protection enables the effective establishment of S. aureus infection. Understanding augmentation not only explains an important facet of the interaction of S. aureus with our innate immune system, but also provides a platform for the development of novel prophylaxis approaches.
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Affiliation(s)
- Josie F. Gibson
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom
- Florey Institute, University of Sheffield, Sheffield, United Kingdom, Sheffield, United Kingdom
- The Bateson Centre, University of Sheffield, Sheffield, United Kingdom
| | - Grace R. Pidwill
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom
- Florey Institute, University of Sheffield, Sheffield, United Kingdom, Sheffield, United Kingdom
| | - Oliver T. Carnell
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom
- Florey Institute, University of Sheffield, Sheffield, United Kingdom, Sheffield, United Kingdom
| | - Bas G. J. Surewaard
- Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Department of Microbiology, Immunology and Infectious Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Daria Shamarina
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom
- Florey Institute, University of Sheffield, Sheffield, United Kingdom, Sheffield, United Kingdom
| | - Joshua A. F. Sutton
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom
- Florey Institute, University of Sheffield, Sheffield, United Kingdom, Sheffield, United Kingdom
| | - Charlotte Jeffery
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom
| | | | - Cristel Archambaud
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Matthew K. Siggins
- Department of Infectious Disease, Imperial College London, London, United Kingdom
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Eric J. G. Pollitt
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom
- Florey Institute, University of Sheffield, Sheffield, United Kingdom, Sheffield, United Kingdom
| | - Simon A. Johnston
- Florey Institute, University of Sheffield, Sheffield, United Kingdom, Sheffield, United Kingdom
- The Bateson Centre, University of Sheffield, Sheffield, United Kingdom
- Department of Infection, Immunity and Cardiovascular disease, Medical School, University of Sheffield, Sheffield, United Kingdom
| | - Pascale Serror
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Shiranee Sriskandan
- Department of Infectious Disease, Imperial College London, London, United Kingdom
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Stephen A. Renshaw
- Florey Institute, University of Sheffield, Sheffield, United Kingdom, Sheffield, United Kingdom
- The Bateson Centre, University of Sheffield, Sheffield, United Kingdom
- Department of Infection, Immunity and Cardiovascular disease, Medical School, University of Sheffield, Sheffield, United Kingdom
- * E-mail: (SAR); (SJF)
| | - Simon J. Foster
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom
- Florey Institute, University of Sheffield, Sheffield, United Kingdom, Sheffield, United Kingdom
- * E-mail: (SAR); (SJF)
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Xie L, Zhou A, Zhao J, Tang Y, Zhao R, Zhou Y, Cao G, Zhong C, Li J. Comparative insights into multiple drug resistance determinants in Stenotrophomonas maltophilia MER1. J Glob Antimicrob Resist 2021; 27:20-25. [PMID: 34365056 DOI: 10.1016/j.jgar.2021.07.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 07/19/2021] [Accepted: 07/22/2021] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES Multidrug-resistant (MDR) Stenotrophomonas maltophilia strain MER1 was isolated from hospital wastewater in Shandong Province, China. This study aimed to determine the genetic determinants related to its striking MDR phenotype. METHODS Antimicrobial susceptibility testing of strain MER1 was performed by disk diffusion on Mueller-Hinton agar plates, and MICs were interpreted according to Clinical and Laboratory Standards Institute breakpoints. The genome of MER1 was sequenced and assembled using PacBio RS II and BGISEQ-500 platforms. Antimicrobial resistance determinants together with other transferability or adaptability determinants were identified by comparative genomics. Phylogenetic and contextual assays for these elements were conducted to assess the risk of spread of MER1. RESULTS Antimicrobial susceptibility testing revealed that strain MER1 is resistant to nine different antibiotics, including ampicillin, meropenem, amikacin, erythromycin, vancomycin, tetracycline, tigecycline, colistin and ceftazidime. Several genes were identified encoding efflux pumps and drug-inactivating agents, accounting for resistance to the above antibiotics, including meropenem, tigecycline and colistin regarded as last-line therapies for infections caused by MDR Gram-negative bacteria. MER1 co-harbours two non-mobile mcr homologues. A novel genomic region of variability was demonstrated to confer bacterial robustness and adaptability upon strain MER1. CONCLUSION Collective efforts revealed the MDR properties and potential genetic determinants of S. maltophilia MER1 isolated from hospital wastewater. Comparative genomic analysis of S. maltophilia MER1 may provide insights into the prevention and treatment of antimicrobial-resistant infections. Our findings raise concern that the MDR genes in the reservoir of S. maltophilia may further spread into various ecological niches or medically high-risk pathogens.
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Affiliation(s)
- Linlin Xie
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China; Jiangxi Key Laboratory of Natural Product and Functional Food, College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang, China
| | - Aiping Zhou
- Department of Laboratory Medicine, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Jia Zhao
- School of Municipal and Environmental Engineering, Shandong Jianzhu University, Jinan, China
| | - Yuhang Tang
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Rui Zhao
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Yingping Zhou
- School of Municipal and Environmental Engineering, Shandong Jianzhu University, Jinan, China
| | - Guangxiang Cao
- College of Biomedical Sciences, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, China
| | - Chuanqing Zhong
- School of Municipal and Environmental Engineering, Shandong Jianzhu University, Jinan, China.
| | - Jun Li
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China; Jiangxi Key Laboratory of Natural Product and Functional Food, College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang, China.
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Kalindamar S, Abdelhamed H, Kordon AO, Pinchuk LM, Karsi A. Hemolysin Co-regulated Family Proteins Hcp1 and Hcp2 Contribute to Edwardsiella ictaluri Pathogenesis. Front Vet Sci 2021; 8:681609. [PMID: 34150898 PMCID: PMC8207204 DOI: 10.3389/fvets.2021.681609] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Accepted: 05/07/2021] [Indexed: 01/22/2023] Open
Abstract
Edwardsiella ictaluri is a Gram-negative facultative intracellular pathogen causing enteric septicemia of catfish (ESC), a devastating disease resulting in significant economic losses in the U.S. catfish industry. Bacterial secretion systems are involved in many bacteria's virulence, and Type VI Secretion System (T6SS) is a critical apparatus utilized by several pathogenic Gram-negative bacteria. E. ictaluri strain 93-146 genome has a complete T6SS operon with 16 genes, but the roles of these genes are still not explored. In this research, we aimed to understand the roles of two hemolysin co-regulated family proteins, Hcp1 (EvpC) and Hcp2. To achieve this goal, single and double E. ictaluri mutants (EiΔevpC, EiΔhcp2, and EiΔevpCΔhcp2) were generated and characterized. Catfish peritoneal macrophages were able to kill EiΔhcp2 better than EiΔevpC, EiΔevpCΔhcp2, and E. ictaluri wild-type (EiWT). The attachment of EiΔhcp2 and EiΔevpCΔhcp2 to ovary cells significantly decreased compared to EiWT whereas the cell invasion rates of these mutants were the same as that of EiWT. Mutants exposed to normal catfish serum in vitro showed serum resistance. The fish challenges demonstrated that EiΔevpC and EiΔevpCΔhcp2 were attenuated completely and provided excellent protection against EiWT infection in catfish fingerlings. Interestingly, EiΔhcp2 caused higher mortality than that of EiWT in catfish fingerlings, and severe clinical signs were observed. Although fry were more susceptible to vaccination with EiΔevpC and EiΔevpCΔhcp2, their attenuation and protection were significantly higher compared to EiWT and sham groups, respectively. Taken together, our data indicated that evpC (hcp1) is involved in E. ictaluri virulence in catfish while hcp2 is involved in adhesion to epithelial cells and survival inside catfish macrophages.
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Affiliation(s)
- Safak Kalindamar
- Department of Molecular Biology and Genetics, Faculty of Arts and Sciences, Ordu University, Ordu, Turkey
| | - Hossam Abdelhamed
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, United States
| | - Adef O Kordon
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, United States
| | - Lesya M Pinchuk
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, United States
| | - Attila Karsi
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, United States
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Li J, Xie L, Qian S, Tang Y, Shen M, Li S, Wang J, Xiong L, Lu J, Zhong W. A Type VI Secretion System Facilitates Fitness, Homeostasis, and Competitive Advantages for Environmental Adaptability and Efficient Nicotine Biodegradation. Appl Environ Microbiol 2021; 87:e03113-20. [PMID: 33608299 PMCID: PMC8091027 DOI: 10.1128/aem.03113-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 02/15/2021] [Indexed: 12/29/2022] Open
Abstract
Gram-negative bacteria employ secretion systems to translocate proteinaceous effectors from the cytoplasm to the extracellular milieu, thus interacting with the surrounding environment or microniche. It is known that bacteria can benefit from the type VI secretion system (T6SS) by transporting ions to combat reactive oxygen species (ROS). Here, we report that T6SS activities conferred tolerance to nicotine-induced oxidative stress in Pseudomonas sp. strain JY-Q, a highly active nicotine degradation strain isolated from tobacco waste extract. AA098_13375 was identified to encode a dual-functional effector with antimicrobial and anti-ROS activities. Wild-type strain JY-Q grew better than the AA098_13375 deletion mutant in nicotine-containing medium by antagonizing increased intracellular ROS levels. It was, therefore, tentatively designated TseN (type VI secretion system effector for nicotine tolerance), homologs of which were observed to be broadly ubiquitous in Pseudomonas species. TseN was identified as a Tse6-like bacteriostatic toxin via monitoring intracellular NAD+ TseN presented potential antagonism against ROS to fine tune the heavy traffic of nicotine metabolism in strain JY-Q. It is feasible that the dynamic tuning of NAD+ driven by TseN could satisfy demands from nicotine degradation with less cytotoxicity. In this scenario, T6SS involves a fascinating accommodation cascade that prompts constitutive biotransformation of N-heterocyclic aromatics by improving bacterial robustness/growth. In summary, the T6SS in JY-Q mediated resistance to oxidative stress and promoted bacterial fitness via a contact-independent growth competitive advantage, in addition to the well-studied T6SS-dependent antimicrobial activities.IMPORTANCE Mixtures of various pollutants and the coexistence of numerous species of organisms are usually found in adverse environments. Concerning biodegradation of nitrogen-heterocyclic contaminants, the scientific community has commonly focused on screening functional enzymes that transform pollutants into intermediates of attenuated toxicity or for primary metabolism. Here, we identified dual roles of the T6SS effector TseN in Pseudomonas sp. strain JY-Q, which is capable of degrading nicotine. The T6SS in strain JY-Q is able to deliver TseN to kill competitors and provide a growth advantage by a contact-independent pattern. TseN could monitor the intracellular NAD+ level by its hydrolase activity, causing cytotoxicity in competitive rivals but metabolic homeostasis on JY-Q. Moreover, JY-Q could be protected from TseN toxicity by the immunity protein TsiN. In conclusion, we found that TseN with cytotoxicity to bacterial competitors facilitated the nicotine tolerance of JY-Q. We therefore reveal a working model between T6SS and nicotine metabolism. This finding indicates that multiple diversified weapons have been evolved by bacteria for their growth and robustness.
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Affiliation(s)
- Jun Li
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Linlin Xie
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Shulan Qian
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Yuhang Tang
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Mingjie Shen
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Shanshan Li
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Jie Wang
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Lie Xiong
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Jie Lu
- Department of Infectious Diseases, Rui Jin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Weihong Zhong
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
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Gomes TAT, Dobrindt U, Farfan MJ, Piazza RMF. Editorial: Interaction of Pathogenic Escherichia coli With the Host: Pathogenomics, Virulence and Antibiotic Resistance. Front Cell Infect Microbiol 2021; 11:654283. [PMID: 33869085 PMCID: PMC8044399 DOI: 10.3389/fcimb.2021.654283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 03/17/2021] [Indexed: 11/13/2022] Open
Affiliation(s)
- Tânia A T Gomes
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Ulrich Dobrindt
- Institute of Hygiene, University of Muenster, Muenster, Germany
| | - Mauricio J Farfan
- Laboratorio Clínico, Hospital Dr. Luis Calvo Mackenna, Santiago, Chile.,Departamento de Pediatría y Cirugía Infantil, Hospital Dr. Luis Calvo Mackenna, Facultad de Medicina, Universidad de Chile, Santiago, Chile
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Xing Z, Li H, Li M, Gao R, Guo C, Mi S. Disequilibrium in chicken gut microflora with avian colibacillosis is related to microenvironment damaged by antibiotics. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 762:143058. [PMID: 33127154 DOI: 10.1016/j.scitotenv.2020.143058] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 09/25/2020] [Accepted: 10/10/2020] [Indexed: 06/11/2023]
Abstract
The avian colibacillosis outbreak is a disease that threatens public health, poultry production, and economic interests, even after antibiotic feed addition. It is known that avian pathogenic E. coli is a major pathogenic factor; however, the systemic characteristics of gut flora in disease samples and how pathogens grow remain unknown. To study these issues in depth, we used the whole microbial genome shotgun sequencing technique to compare entire microbes in diseased and healthy broiler chickens. We found that it was not only E. coli that increased substantially, but most pathogenic flora also increased significantly in diseased samples. Subsequently, we proved that aminoglycoside antibiotic resistance genes were mainly found in non-E. coli strains. This suggests that E. coli survival under antibiotic stress was due to the cooperative resistance from non-E. coli strains. Among all these increasing strains, attaching and effacing pathogens could damage host intestinal epithelial cells to release oxygen in the gut to make the microenvironment more adaptable for E. coli strains. Furthermore, we observed that the functions of the T4SS/T6SS secretion system were dramatically enhanced, which could help E. coli to compete and enlarge their living spaces. Ultimately, pathogenic E. coli accumulated to cause avian colibacillosis. This study provides a new insight into intestinal microecology in diseased individuals, which would propose new treatment options for avian colibacillosis from a metagenome perspective.
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Affiliation(s)
- Zhikai Xing
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, China National Center for Bioinformation, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Hui Li
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, China National Center for Bioinformation, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Meng Li
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, China National Center for Bioinformation, Beijing, China
| | - Ran Gao
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, China National Center for Bioinformation, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Chongye Guo
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, China National Center for Bioinformation, Beijing, China.
| | - Shuangli Mi
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, China National Center for Bioinformation, Beijing, China; University of Chinese Academy of Sciences, Beijing, China.
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43
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Naïli I, Gardette M, Garrivier A, Daniel J, Desvaux M, Pizza M, Gobert A, Marchal T, Loukiadis E, Jubelin G. Interplay between enterohaemorrhagic Escherichia coli and nitric oxide during the infectious process. Emerg Microbes Infect 2021; 9:1065-1076. [PMID: 32459575 PMCID: PMC7336997 DOI: 10.1080/22221751.2020.1768804] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Enterohaemorrhagic Escherichia coli (EHEC) are bacterial pathogens responsible for life-threatening diseases in humans such as bloody diarrhoea and the hemolytic and uremic syndrome. To date, no specific therapy is available and treatments remain essentially symptomatic. In recent years, we demonstrated in vitro that nitric oxide (NO), a major mediator of the intestinal immune response, strongly represses the synthesis of the two cardinal virulence factors in EHEC, namely Shiga toxins (Stx) and the type III secretion system, suggesting NO has a great potential to protect against EHEC infection. In this study, we investigated the interplay between NO and EHEC in vivo using mouse models of infection. Using a NO-sensing reporter strain, we determined that EHEC sense NO in the gut of infected mice. Treatment of infected mice with a specific NOS inhibitor increased EHEC adhesion to the colonic mucosa but unexpectedly decreased Stx activity in the gastrointestinal tract, protecting mice from renal failure. Taken together, our data indicate that NO can have both beneficial and detrimental consequences on the outcome of an EHEC infection, and underline the importance of in vivo studies to increase our knowledge in host–pathogen interactions.
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Affiliation(s)
- Ilham Naïli
- Université Clermont Auvergne, INRAE, MEDiS, F-63000 Clermont-Ferrand, France.,GSK, Siena, Italy
| | - Marion Gardette
- Université Clermont Auvergne, INRAE, MEDiS, F-63000 Clermont-Ferrand, France.,Université de Lyon, CNRS, INRAE, Université Claude Bernard Lyon 1, VetAgro Sup, Laboratoire d'Ecologie Microbienne, F-63280 Marcy l'Etoile, France
| | - Annie Garrivier
- Université Clermont Auvergne, INRAE, MEDiS, F-63000 Clermont-Ferrand, France
| | - Julien Daniel
- Université Clermont Auvergne, INRAE, MEDiS, F-63000 Clermont-Ferrand, France
| | - Mickaël Desvaux
- Université Clermont Auvergne, INRAE, MEDiS, F-63000 Clermont-Ferrand, France
| | | | - Alain Gobert
- Université Clermont Auvergne, INRAE, MEDiS, F-63000 Clermont-Ferrand, France
| | - Thierry Marchal
- VetAgro Sup, Laboratoire vétérinaire d'histopathologie, F-63280 Marcy-l'Etoile, France
| | - Estelle Loukiadis
- Université de Lyon, CNRS, INRAE, Université Claude Bernard Lyon 1, VetAgro Sup, Laboratoire d'Ecologie Microbienne, F-63280 Marcy l'Etoile, France.,VetAgro Sup, Laboratoire national de référence des E. coli, F-63280 Marcy-l'Etoile, France
| | - Grégory Jubelin
- Université Clermont Auvergne, INRAE, MEDiS, F-63000 Clermont-Ferrand, France
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T6SS Mediated Stress Responses for Bacterial Environmental Survival and Host Adaptation. Int J Mol Sci 2021; 22:ijms22020478. [PMID: 33418898 PMCID: PMC7825059 DOI: 10.3390/ijms22020478] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 12/25/2020] [Accepted: 01/01/2021] [Indexed: 02/07/2023] Open
Abstract
The bacterial type VI secretion system (T6SS) is a protein secretion apparatus widely distributed in Gram-negative bacterial species. Many bacterial pathogens employ T6SS to compete with the host and to coordinate the invasion process. The T6SS apparatus consists of a membrane complex and an inner tail tube-like structure that is surrounded by a contractile sheath and capped with a spike complex. A series of antibacterial or antieukaryotic effectors is delivered by the puncturing device consisting of a Hcp tube decorated by the VgrG/PAAR complex into the target following the contraction of the TssB/C sheath, which often leads to damage and death of the competitor and/or host cells. As a tool for protein secretion and interspecies interactions, T6SS can be triggered by many different mechanisms to respond to various physiological conditions. This review summarizes our current knowledge of T6SS in coordinating bacterial stress responses against the unfavorable environmental and host conditions.
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Hu L, Yu F, Liu M, Chen J, Zong B, Zhang Y, Chen T, Wang C, Zhang T, Zhang J, Zhu Y, Wang X, Chen H, Tan C. RcsB-dependent regulation of type VI secretion system in porcine extra-intestinal pathogenic Escherichia coli. Gene 2020; 768:145289. [PMID: 33181257 DOI: 10.1016/j.gene.2020.145289] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 10/26/2020] [Accepted: 10/29/2020] [Indexed: 02/02/2023]
Abstract
Signal transduction system and specialized secretory devices are crucial for bacteria to sense and adequately adapt in adverse environmental conditions. Therefore, it's crucial for microbes to detect and respond to lethal attacks when envelope is perturbed so as to minimize and fix the damage in milieu. We investigated the adaptive response of porcine extra-intestinal pathogenic Escherichia coli PCN033 to polymyxin B challenge. Treatment with polymyxin B led to rapid and robust activation of Rcs system via RcsF, as well as the accumulation of reactive oxygen species. ExPEC T6SS expression was strongly induced by RcsB in Rcs system, resulting in the reduction in the damage to constitute a survival strategy. Finally, we show that T6SS of ExPEC is involved in its pathogenicity in mouse model. Compared with the wild type strain, the deletion of T6SS genes led to a decrease in the organ colonization ability, and the RcsFS2DM3Q mutant that caused Rcs activation had a stronger colonization ability than the wild type strain. In conclusion, Rcs system orchestrates Rcs cascade to trigger antioxidant defense of T6SS, and presents a typical model in which a bacterium reschedule its transcription network via the Rcs phosphorelay pathway in response to membrane perturbations for survival and pathogenesis.
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Affiliation(s)
- Linlin Hu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Feifei Yu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Manli Liu
- Hubei Biopesticide Engineering Research Centre, Hubei Academy of Agricultural Sciences, Wuhan 430064, Hubei, China
| | - Jing Chen
- Guangzhou Medical University, Guangzhou 511436, Guangdong, China
| | - Bingbing Zong
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Yanyan Zhang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Tumei Chen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Chenchen Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Tongchao Zhang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Junli Zhang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Yongwei Zhu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Xiangru Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, Hubei, China; Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Centre for Sustainable Pig Production, Wuhan, Hubei 430070, China
| | - Huanchun Chen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, Hubei, China; Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Centre for Sustainable Pig Production, Wuhan, Hubei 430070, China
| | - Chen Tan
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, Hubei, China; Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Centre for Sustainable Pig Production, Wuhan, Hubei 430070, China.
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46
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Liu L, Song L, Deng R, Lan R, Jin W, Tran Van Nhieu G, Cao H, Liu Q, Xiao Y, Li X, Meng G, Ren Z. Citrobacter freundii Activation of NLRP3 Inflammasome via the Type VI Secretion System. J Infect Dis 2020; 223:2174-2185. [PMID: 33151309 DOI: 10.1093/infdis/jiaa692] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 11/03/2020] [Indexed: 12/27/2022] Open
Abstract
Citrobacter freundii is a significant cause of human infections, responsible for food poisoning, diarrhea, and urinary tract infections. We previously identified a highly cytotoxic and adhesive C. freundii strain CF74 expressing a type VI secretion system (T6SS). In this study, we showed that in mice-derived macrophages, C. freundii CF74 activated the Nucleotide Oligomerization Domain -Like Receptor Family, Pyrin Domain Containing 3(NLRP3) inflammasomes in a T6SS-dependent manner. The C. freundii T6SS activated the inflammasomes mainly through caspase 1 and mediated pyroptosis of macrophages by releasing the cleaved gasdermin-N domain. The CF74 T6SS was required for flagellin-induced interleukin 1β release by macrophages. We further show that the T6SS tail component and effector, hemolysin co-regulation protein-2 (Hcp-2), was necessary and sufficient to trigger NLRP3 inflammasome activation. In vivo, the T6SS played a key role in mediating interleukin 1β secretion and the survival of mice during C. freundii infection in mice. These findings provide novel insights into the role of T6SS in the pathogenesis of C. freundii.
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Affiliation(s)
- Liyun Liu
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Research Units of Discovery of Unknown Bacteria and Function (2018RU010), Chinese Academy of Medical Sciences, Beijing, China
| | - Liqiong Song
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Research Units of Discovery of Unknown Bacteria and Function (2018RU010), Chinese Academy of Medical Sciences, Beijing, China
| | - Rong Deng
- The Center for Microbes, Development and Health, CAS Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences; University of Chinese Academy of Sciences, Shanghai, China
| | - Ruiting Lan
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Wenjie Jin
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Research Units of Discovery of Unknown Bacteria and Function (2018RU010), Chinese Academy of Medical Sciences, Beijing, China
| | - Guy Tran Van Nhieu
- Calcium Signaling and Microbial Infections, Inserm U1282, Laboratoire de Biologie et Pharmacologie Appliquée, UMR 8113, Ecole Normale Supérieure Paris Saclay, Gif-sur-Yvette, France
| | - Huifang Cao
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Qin Liu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Yuchun Xiao
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Research Units of Discovery of Unknown Bacteria and Function (2018RU010), Chinese Academy of Medical Sciences, Beijing, China
| | - Xianping Li
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Research Units of Discovery of Unknown Bacteria and Function (2018RU010), Chinese Academy of Medical Sciences, Beijing, China
| | - Guangxun Meng
- The Center for Microbes, Development and Health, CAS Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences; University of Chinese Academy of Sciences, Shanghai, China
| | - Zhihong Ren
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Research Units of Discovery of Unknown Bacteria and Function (2018RU010), Chinese Academy of Medical Sciences, Beijing, China
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47
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Monjarás Feria J, Valvano MA. An Overview of Anti-Eukaryotic T6SS Effectors. Front Cell Infect Microbiol 2020; 10:584751. [PMID: 33194822 PMCID: PMC7641602 DOI: 10.3389/fcimb.2020.584751] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Accepted: 09/22/2020] [Indexed: 12/24/2022] Open
Abstract
The type VI secretion system (T6SS) is a transmembrane multiprotein nanomachine employed by many Gram-negative bacterial species to translocate, in a contact-dependent manner, effector proteins into adjacent prokaryotic or eukaryotic cells. Typically, the T6SS gene cluster encodes at least 13 conserved core components for the apparatus assembly and other less conserved accessory proteins and effectors. It functions as a contractile tail machine comprising a TssB/C sheath and an expelled puncturing device consisting of an Hcp tube topped by a spike complex of VgrG and PAAR proteins. Contraction of the sheath propels the tube out of the bacterial cell into a target cell and leads to the injection of toxic proteins. Different bacteria use the T6SS for specific roles according to the niche and versatility of the organism. Effectors are present both as cargo (by non-covalent interactions with one of the core components) or specialized domains (fused to structural components). Although several anti-prokaryotic effectors T6SSs have been studied, recent studies have led to a substantial increase in the number of characterized anti-eukaryotic effectors. Against eukaryotic cells, the T6SS is involved in modifying and manipulating diverse cellular processes that allows bacteria to colonize, survive and disseminate, including adhesion modification, stimulating internalization, cytoskeletal rearrangements and evasion of host innate immune responses.
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Affiliation(s)
| | - Miguel A. Valvano
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, United Kingdom
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Wood TE, Aksoy E, Hachani A. From Welfare to Warfare: The Arbitration of Host-Microbiota Interplay by the Type VI Secretion System. Front Cell Infect Microbiol 2020; 10:587948. [PMID: 33194832 PMCID: PMC7604300 DOI: 10.3389/fcimb.2020.587948] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 09/22/2020] [Indexed: 12/17/2022] Open
Abstract
The health of mammals depends on a complex interplay with their microbial ecosystems. Compartments exposed to external environments such as the mucosal surfaces of the gastrointestinal tract accommodate the gut microbiota, composed by a wide range of bacteria. The gut microbiome confers benefits to the host, including expansion of metabolic potential and the development of an immune system that can robustly protect from external and internal insults. The cooperation between gut microbiome and host is enabled in part by the formation of partitioned niches that harbor diverse bacterial phyla. Bacterial secretion systems are commonly employed to manipulate the composition of these local environments. Here, we explore the roles of the bacterial type VI secretion system (T6SS), present in ~25% of gram-negative bacteria, including many symbionts, in the establishment and perturbation of bacterial commensalism, and symbiosis in host mucosal sites. This versatile apparatus drives bacterial competition, although in some cases can also interfere directly with host cells and facilitate nutrient acquisition. In addition, some bacterial pathogens cause disease when their T6SS leads to dysbiosis and subverts host immune responses in defined animal models. This review explores our knowledge of the T6SS in the context of the “host-microbiota-pathogen” triumvirate and examines contexts in which the importance of this secretion system may be underappreciated.
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Affiliation(s)
- Thomas E Wood
- Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital, Boston, MA, United States.,Department of Microbiology, Harvard Medical School, Boston, MA, United States
| | - Ezra Aksoy
- Centre for Biochemical Pharmacology, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Abderrahman Hachani
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
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49
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Soria-Bustos J, Ares MA, Gómez-Aldapa CA, González-Y-Merchand JA, Girón JA, De la Cruz MA. Two Type VI Secretion Systems of Enterobacter cloacae Are Required for Bacterial Competition, Cell Adherence, and Intestinal Colonization. Front Microbiol 2020; 11:560488. [PMID: 33072020 PMCID: PMC7541819 DOI: 10.3389/fmicb.2020.560488] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Accepted: 08/12/2020] [Indexed: 12/22/2022] Open
Abstract
Enterobacter cloacae has emerged as an opportunistic pathogen in healthcare-associated infections. Analysis of the genomic sequences of several E. cloacae strains revealed the presence of genes that code for expression of at least one type VI secretion system (T6SS). Here, we report that E. cloacae strain ATCC 13047 codes for two functional T6SS named T6SS-1 and T6SS-2. T6SS-1 and T6SS-2 were preferentially expressed in tryptic soy broth and tissue culture medium (DMEM), respectively. Mutants in T6SS-1-associated genes clpV1 and hcp1 significantly affected their ability of inter- and intra-bacterial killing indicating that T6SS-1 is required for bacterial competition. In addition, the Hcp effector protein was detected in supernatants of E. cloacae cultures and a functional T6SS-1 was required for the secretion of this protein. A clpV2 mutant was impaired in both biofilm formation and adherence to epithelial cells, supporting the notion that these phenotypes are T6SS-2 dependent. In vivo data strongly suggest that both T6SSs are required for intestinal colonization because single and double mutants in clpV1 and clpV2 genes were defective in gut colonization in mice. We conclude that the two T6SSs are involved in the pathogenesis scheme of E. cloacae with specialized functions in the interaction with other bacteria and with host cells.
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Affiliation(s)
- Jorge Soria-Bustos
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City, Mexico.,Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Miguel A Ares
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City, Mexico
| | - Carlos A Gómez-Aldapa
- Instituto de Ciencias Básicas e Ingeniería, Universidad Autónoma del Estado de Hidalgo, Carretera Pachuca-Tulancingo Km 4.5 Mineral de la Reforma, Hidalgo, Mexico
| | - Jorge A González-Y-Merchand
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Jorge A Girón
- Centro de Detección Biomolecular, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
| | - Miguel A De la Cruz
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City, Mexico
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Bosák J, Hrala M, Micenková L, Šmajs D. Non-antibiotic antibacterial peptides and proteins of Escherichia coli: efficacy and potency of bacteriocins. Expert Rev Anti Infect Ther 2020; 19:309-322. [PMID: 32856960 DOI: 10.1080/14787210.2020.1816824] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
INTRODUCTION The emergence and spread of antibiotic resistance among pathogenic bacteria drives the search for alternative antimicrobial therapies. Bacteriocins represent a potential alternative to antibiotic treatment. In contrast to antibiotics, bacteriocins are peptides or proteins that have relatively narrow spectra of antibacterial activities and are produced by a wide range of bacterial species. Bacteriocins of Escherichia coli are historically classified as microcins and colicins, and, until now, more than 30 different bacteriocin types have been identified and characterized. AREAS COVERED We performed bibliographical searches of online databases to review the literature regarding bacteriocins produced by E. coli with respect to their occurrence, bacteriocin role in bacterial colonization and pathogenicity, and application of their antimicrobial effect. EXPERT OPINION The potential use of bacteriocins for applications in human and animal medicine and the food industry includes (i) the use of bacteriocin-producing probiotic strains, (ii) recombinant production in plants and application in food, and (iii) application of purified bacteriocins.
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Affiliation(s)
- Juraj Bosák
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Matěj Hrala
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Lenka Micenková
- Research Centre for Toxic Compounds in the Environment, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - David Šmajs
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
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