1
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Borovaya TG, Cherkasova MN, Zhukhovitsky VG, Laskavy VN, Sednev OM. Assessment of Modulating Effect of the Experimental Drug Astrabionorm on Synthesis of Proinflammatory Cytokine IL-1β and Anti-Inflammatory Cytokine IL-10 in the Splenic Red Pulp Cells in a Mouse Model of Sepsis. Bull Exp Biol Med 2024:10.1007/s10517-024-06108-w. [PMID: 38907061 DOI: 10.1007/s10517-024-06108-w] [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: 07/03/2023] [Indexed: 06/23/2024]
Abstract
An indirect immunohistochemical method was used to study the production of proinflammatory (IL-1β) and anti-inflammatory (IL-10) cytokines in the spleen cells of mature male C57BL/6 mice with an experimental model of sepsis and during treatment with a drug based on formic acid aldehyde (Astrabionorm). Clinical isolates of two strains of Pseudomonas aeruginosa were used. In the red pulp of the spleen, interleukin-positive cells represented by mononuclear forms were identified, as well as differences in the intensity of immunohistochemical staining of these cells for the studied interleukins in the two models used. A modulating role of the drug in the production of interleukins by the splenic red pulp cells during sepsis is assumed.
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Affiliation(s)
- T G Borovaya
- N. F. Gamaleya National Research Center of Epidemiology and Microbiology, Ministry of Health of the Russian Federation, Moscow, Russia
| | - M N Cherkasova
- N. F. Gamaleya National Research Center of Epidemiology and Microbiology, Ministry of Health of the Russian Federation, Moscow, Russia
| | - V G Zhukhovitsky
- N. F. Gamaleya National Research Center of Epidemiology and Microbiology, Ministry of Health of the Russian Federation, Moscow, Russia.
- Russian Medical Academy of Continuous Professional Education, Ministry of Health of the Russian Federation, Moscow, Russia.
| | - V N Laskavy
- LLC "Research Institute of Medical and Veterinary Biotechnologies", Moscow, Russia
| | - O M Sednev
- LLC "Research Institute of Medical and Veterinary Biotechnologies", Moscow, Russia
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2
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Shankar UN, Shiraz M, Kumar P, Akif M. A comprehensive in silico analysis of putative outer membrane and secretory hydrolases from the pathogenic Leptospira: Possible implications in pathogenesis. Biotechnol Appl Biochem 2024. [PMID: 38733098 DOI: 10.1002/bab.2596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 04/22/2024] [Indexed: 05/13/2024]
Abstract
Outer surface/membrane and virulent secretory proteins are primarily crucial for pathogenesis. Secreted and outer membrane hydrolases of many pathogens play an important role in attenuating the host immune system. Leptospira expresses many such proteins, and few have been characterized to display various roles, including host immune evasion. However, identification, classification, characterization, and elucidation of the possible role of Leptospira's outer membrane and secretory hydrolases have yet to be explored. In the present study, we used bioinformatics tools to predict exported proteins from the pathogenic Leptospira proteome. Moreover, we focused on secretory and outer membrane putative hydrolases from the exported proteins to generate a deeper understanding. Our analysis yielded four putative outer/secretory hydrolases, LIC_10995, LIC_11183, LIC_11463, and LIC_12988, containing α/β hydrolase fold and displayed similarity with lipase motif. Moreover, their conservation analysis of the predicted hydrolases across the spectrum of different Leptospira species showed high clustering with the pathogenic species. Outer membrane and secretory proteins with lipolytic activity may have a role in pathogenesis. This is the first bioinformatics analysis of secretory and outer membrane α/β hydrolases from leptospiral species. However, experimental studies are indeed required to unravel this possibility.
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Affiliation(s)
- Umate Nachiket Shankar
- Laboratory of Structural Biology, Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Mohd Shiraz
- Laboratory of Structural Biology, Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Pankaj Kumar
- Laboratory of Structural Biology, Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Mohd Akif
- Laboratory of Structural Biology, Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, India
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3
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Neuber J, Lang C, Aurass P, Flieger A. Tools and mechanisms of vacuolar escape leading to host egress in Legionella pneumophila infection: Emphasis on bacterial phospholipases. Mol Microbiol 2024; 121:368-384. [PMID: 37891705 DOI: 10.1111/mmi.15183] [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: 06/28/2023] [Revised: 09/29/2023] [Accepted: 10/06/2023] [Indexed: 10/29/2023]
Abstract
The phenomenon of host cell escape exhibited by intracellular pathogens is a remarkably versatile occurrence, capable of unfolding through lytic or non-lytic pathways. Among these pathogens, the bacterium Legionella pneumophila stands out, having adopted a diverse spectrum of strategies to disengage from their host cells. A pivotal juncture that predates most of these host cell escape modalities is the initial escape from the intracellular compartment. This critical step is increasingly supported by evidence suggesting the involvement of several secreted pathogen effectors, including lytic proteins. In this intricate landscape, L. pneumophila emerges as a focal point for research, particularly concerning secreted phospholipases. While nestled within its replicative vacuole, the bacterium deftly employs both its type II (Lsp) and type IVB (Dot/Icm) secretion systems to convey phospholipases into either the phagosomal lumen or the host cell cytoplasm. Its repertoire encompasses numerous phospholipases A (PLA), including three enzymes-PlaA, PlaC, and PlaD-bearing the GDSL motif. Additionally, there are 11 patatin-like phospholipases A as well as PlaB. Furthermore, the bacterium harbors three extracellular phospholipases C (PLCs) and one phospholipase D. Within this comprehensive review, we undertake an exploration of the pivotal role played by phospholipases in the broader context of phagosomal and host cell egress. Moreover, we embark on a detailed journey to unravel the established and potential functions of the secreted phospholipases of L. pneumophila in orchestrating this indispensable process.
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Affiliation(s)
- Jonathan Neuber
- Division of Enteropathogenic Bacteria and Legionella, Robert Koch Institute, Wernigerode, Germany
| | - Christina Lang
- Division of Enteropathogenic Bacteria and Legionella, Robert Koch Institute, Wernigerode, Germany
| | - Philipp Aurass
- Division of Enteropathogenic Bacteria and Legionella, Robert Koch Institute, Wernigerode, Germany
| | - Antje Flieger
- Division of Enteropathogenic Bacteria and Legionella, Robert Koch Institute, Wernigerode, Germany
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4
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Serna Villa V, Ren X. Lung Progenitor and Stem Cell Transplantation as a Potential Regenerative Therapy for Lung Diseases. Transplantation 2024:00007890-990000000-00675. [PMID: 38416452 DOI: 10.1097/tp.0000000000004959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/29/2024]
Abstract
Chronic lung diseases are debilitating illnesses ranking among the top causes of death globally. Currently, clinically available therapeutic options capable of curing chronic lung diseases are limited to lung transplantation, which is hindered by donor organ shortage. This highlights the urgent need for alternative strategies to repair damaged lung tissues. Stem cell transplantation has emerged as a promising avenue for regenerative treatment of the lung, which involves delivery of healthy lung epithelial progenitor cells that subsequently engraft in the injured tissue and further differentiate to reconstitute the functional respiratory epithelium. These transplanted progenitor cells possess the remarkable ability to self-renew, thereby offering the potential for sustained long-term treatment effects. Notably, the transplantation of basal cells, the airway stem cells, holds the promise for rehabilitating airway injuries resulting from environmental factors or genetic conditions such as cystic fibrosis. Similarly, for diseases affecting the alveoli, alveolar type II cells have garnered interest as a viable alveolar stem cell source for restoring the lung parenchyma from genetic or environmentally induced dysfunctions. Expanding upon these advancements, the use of induced pluripotent stem cells to derive lung progenitor cells for transplantation offers advantages such as scalability and patient specificity. In this review, we comprehensively explore the progress made in lung stem cell transplantation, providing insights into the current state of the field and its future prospects.
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Affiliation(s)
- Vanessa Serna Villa
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA
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5
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Zuo S, Xu L, Zhang H, Jiang M, Wu S, Zhang LH, Zhou X, Wang J. FlgI Is a Sec-Dependent Effector of Candidatus Liberibacter asiaticus That Can Be Blocked by Small Molecules Identified Using a Yeast Screen. PLANTS (BASEL, SWITZERLAND) 2024; 13:318. [PMID: 38276775 PMCID: PMC10819201 DOI: 10.3390/plants13020318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 01/11/2024] [Accepted: 01/16/2024] [Indexed: 01/27/2024]
Abstract
Huanglongbing (HLB) is one of the most devastating diseases of citrus worldwide. The phloem-restricted bacterium Candidatus Liberibacter asiaticus (CLas) is considered to be the main pathogen responsible for HLB. There is currently no effective practical strategy for the control of HLB. Our understanding of how pathogens cause HLB is limited because CLas has not been artificially cultured. In this study, 15 potential virulence factors were predicted from the proteome of CLas through DeepVF and PHI-base searches. One among them, FlgI, was found to inhibit yeast growth when expressed in Saccharomyces cerevisiae. The expression of the signal peptide of FlgI fused with PhoA in Escherichia coli resulted in the discovery that FlgI was a novel Sec-dependent secretory protein. We further found that the carboxyl-terminal HA-tagged FlgI was secreted via outer membrane vesicles in Sinorhizobium meliloti. Fluoresence localization of transient expression FlgI-GFP in Nicotiana benthamiana revealed that FlgI is mainly localized in the cytoplasm, cell periphery, and nuclear periphery of tobacco cells. In addition, our experimental results suggest that FlgI has a strong ability to induce callose deposition and cell necrosis in N. benthamiana. Finally, by screening a large library of compounds in a high-throughput format, we found that cyclosporin A restored the growth of FlgI-expressing yeast. These results confirm that FlgI is a novel Sec-dependent effector, enriching our understanding of CLas pathogenicity and helping to develop new and more effective strategies to manage HLB.
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Affiliation(s)
| | | | | | | | | | | | - Xiaofan Zhou
- Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou 510642, China; (S.Z.); (L.X.); (H.Z.); (M.J.); (S.W.); (L.-H.Z.)
| | - Junxia Wang
- Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou 510642, China; (S.Z.); (L.X.); (H.Z.); (M.J.); (S.W.); (L.-H.Z.)
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6
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Xie Q, Wei B, Zhan Z, He Q, Wu K, Chen Y, Liu S, He C, Niu X, Li C, Tang C, Tao J. Arabidopsis membrane protein AMAR1 interaction with type III effector XopAM triggers a hypersensitive response. PLANT PHYSIOLOGY 2023; 193:2768-2787. [PMID: 37648267 DOI: 10.1093/plphys/kiad478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 06/07/2023] [Accepted: 07/27/2023] [Indexed: 09/01/2023]
Abstract
The efficient infection of plants by the bacteria Xanthomonas campestris pv. campestris (Xcc) depends on its type III effectors (T3Es). Although the functions of AvrE family T3Es have been reported in some bacteria, the member XopAM in Xcc has not been studied. As XopAM has low sequence similarity to reported AvrE-T3Es and different reports have shown that these T3Es have different targets in hosts, we investigated the functions of XopAM in the Xcc-plant interaction. Deletion of xopAM from Xcc reduced its virulence in cruciferous crops but increased virulence in Arabidopsis (Arabidopsis thaliana) Col-0, indicating that XopAM may perform opposite functions depending on the host species. We further found that XopAM is a lipase that may target the cytomembrane and that this activity might be enhanced by its membrane-targeted protein XOPAM-ACTIVATED RESISTANCE 1 (AMAR1) in Arabidopsis Col-0. The binding of XopAM to AMAR1 induced an intense hypersensitive response that restricted Xcc proliferation. Our results showed that the roles of XopAM in Xcc infection are not the same as those of other AvrE-T3Es, indicating that the functions of this type of T3E have differentiated during long-term bacterium‒host interactions.
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Affiliation(s)
- Qingbiao Xie
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
| | - Bingzheng Wei
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
| | - Zhaohong Zhan
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
| | - Qiguang He
- Rubber Research Institute, Chinese Academy of Tropical Agricultural Science, Haikou 571101, China
| | - Kejian Wu
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
| | - Yu Chen
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
| | - Shiyao Liu
- Sanya Nanfan Research Institute, Hainan University, Sanya 572024, China
| | - Chaozu He
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
- Sanya Nanfan Research Institute, Hainan University, Sanya 572024, China
- Hainan Yazhou Bay Seed Laboratory, Sanya 572025, China
| | - Xiaolei Niu
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
- Sanya Nanfan Research Institute, Hainan University, Sanya 572024, China
| | - Chunxia Li
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
- Hainan Yazhou Bay Seed Laboratory, Sanya 572025, China
| | - Chaorong Tang
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
| | - Jun Tao
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
- Hainan Yazhou Bay Seed Laboratory, Sanya 572025, China
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7
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Olaniran OB, Donia A, Adeleke OE, Bokhari H. Prevalence of Type III Secretion System (T3SS) and Biofilm Development in Genetically Heterogeneous Clinical Isolates of Pseudomonas aeruginosa from Nigeria. Curr Microbiol 2023; 80:349. [PMID: 37733140 DOI: 10.1007/s00284-023-03467-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 09/01/2023] [Indexed: 09/22/2023]
Abstract
Pseudomonas aeruginosa infection in seriously ill patients is a major concern due to its ability to form biofilm and secrete effector toxins. There is little information on the prevalence of T3SS effector toxins and biofilm production in clinical isolates of P. aeruginosa from Nigeria. The goal of this study is to evaluate the prevalence of T3SS toxins and biofilm production among isolates from selected tertiary hospitals in Nigeria. This study examined 430 clinical isolates from our previous work, comprising 181 MDR (multidrug-resistant) and 249 non-MDR isolates. Biofilm production and type III secretion toxins were determined using colorimetric microtiter plate assay and polymerase chain reaction, respectively. Carbapenem-resistant isolates were typed using REP-PCR and BOX-PCR. Biofilm production was detected in 386/430 (89.8%) of the isolates. Out of 386 biofilm producers, 167 (43.3%) were multidrug-resistant isolates. PCR identified four T3SS virulence types among 430 isolates, including 78 (18.1%) exoU+/exoS- isolates, 343 (79.8%) exoU-/exoS + isolates, 5 (1.2%) exoU+/exoS + isolates, and 4 (0.9%) exoU-/exoS- isolates. Both REP- and BOX-PCR consist of eight clusters. On the REP-PCR dendrogram, ExoU+/ExoS- isolates majorly occupied cluster IV. Clusters IV, VII, and VIII consist of isolates from wounds on BOX-PCR dendrogram. There was a positive association between strong biofilm production and multidrug resistance in our P. aeruginosa isolates. This study identified multidrug-resistant, biofilm-producing P. aeruginosa strains that secrete cytotoxic effectors which are significant virulence factors in P. aeruginosa. This poses a severe risk to our healthcare system and highlights the importance of continuous surveillance to prevent infectious disease outbreaks.
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Affiliation(s)
- Oluwatoyin B Olaniran
- Department of Pharmaceutical Microbiology, Olabisi Onabanjo University, Ago-Iwoye, Nigeria
- Department of Biosciences, Faculty of Science, COMSATS University Islamabad, Islamabad, Pakistan
| | - Ahmed Donia
- Institute for Water and Wastewater Technology, Durban University of Technology, Durban, South Africa
- Department of Biosciences, Faculty of Science, COMSATS University Islamabad, Islamabad, Pakistan
| | - Olufemi E Adeleke
- Department of Pharmaceutical Microbiology, University of Ibadan, Ibadan, Nigeria
| | - Habib Bokhari
- Department of Biosciences, Faculty of Science, COMSATS University Islamabad, Islamabad, Pakistan.
- Kohsar University Murree, Murree, Pakistan.
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8
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Fontana L, Strasfeld L, Hakki M. Pseudomonas aeruginosa ExoU-associated virulence in HCT recipients and patients with hematologic malignancies. Blood Adv 2023; 7:4035-4038. [PMID: 37216281 PMCID: PMC10410125 DOI: 10.1182/bloodadvances.2023009806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 03/15/2023] [Accepted: 04/01/2023] [Indexed: 05/24/2023] Open
Affiliation(s)
- Lauren Fontana
- Division of Infectious Diseases and International Medicine, University of Minnesota, Minneapolis, MN
| | - Lynne Strasfeld
- Division of Infectious Diseases, Oregon Health and Science University, Portland, OR
| | - Morgan Hakki
- Division of Infectious Diseases, Oregon Health and Science University, Portland, OR
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9
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Englisch CN, Wadood NA, Pätzold L, Gallagher A, Krasteva-Christ G, Becker SL, Bischoff M. Establishing an Experimental Pseudomonas aeruginosa Keratitis Model in Mice - Challenges and Solutions. Ann Anat 2023; 249:152099. [PMID: 37105406 DOI: 10.1016/j.aanat.2023.152099] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 03/27/2023] [Accepted: 03/28/2023] [Indexed: 04/29/2023]
Abstract
BACKGROUND With the ongoing increase in antimicrobial resistances seen in bacterial isolates causing a keratitis in humans, animal models have become an important tool to study new antimicrobial therapies. Nevertheless, the establishment of experimental keratitis is difficult. Here, we discuss the impact of different arrangements, including animal age, bacterial strain and dose as well as epithelium removal on the outcome of experimental keratitis. We therefore present the methods and results of our establishing experiments. METHODS Bacterial load determination and flow cytometry were performed using eye homogenate gained from a 72hours lasting murine Pseudomonas aeruginosa keratitis model. Additionally, the intensity of the infection was scored from 0 to 5, the mice weighed, and blood immune cells counted. RESULTS We found that older C57BL/6N mice (8-11 months) are more susceptible to develop a keratitis than younger mice (5-6 weeks). Epithelium removal has no major impact on infectivity and disease progression in aged mice. P. aeruginosa exoU+ strains, such as PA54, should preferentially be used and highly concentrated (∼ 5×107 CFU). Establishing an infection with the exoU- PAO1 derivative DSM 19880 was not possible. CONCLUSIONS We present a replicable method to achieve a successful experimental P. aeruginosa keratitis in C57BL/6N mice that is sustained or aggravated over the observation period of 3 days in 80% of all animals tested. Our work is of particular interest to all researchers planning the establishment of such experimental models. We show some key aspects that can simplify and quicken the procedure, ultimately saving costs and animal life.
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Affiliation(s)
- Colya N Englisch
- Institute for Medical Microbiology and Hygienics, Saarland University, 66421, Homburg/Saar, Germany.
| | - Noran Abdel Wadood
- Institute for Medical Microbiology and Hygienics, Saarland University, 66421, Homburg/Saar, Germany; Institute of Anatomy and Cell Biology, Saarland University, 66421, Homburg/Saar, Germany.
| | - Linda Pätzold
- Institute for Medical Microbiology and Hygienics, Saarland University, 66421, Homburg/Saar, Germany.
| | | | | | - Sören L Becker
- Institute for Medical Microbiology and Hygienics, Saarland University, 66421, Homburg/Saar, Germany.
| | - Markus Bischoff
- Institute for Medical Microbiology and Hygienics, Saarland University, 66421, Homburg/Saar, Germany.
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10
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Kiel A, Creutz I, Rückert C, Kaltschmidt BP, Hütten A, Niehaus K, Busche T, Kaltschmidt B, Kaltschmidt C. Genome-Based Analysis of Virulence Factors and Biofilm Formation in Novel P. aeruginosa Strains Isolated from Household Appliances. Microorganisms 2022; 10:microorganisms10122508. [PMID: 36557761 PMCID: PMC9781345 DOI: 10.3390/microorganisms10122508] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 12/09/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022] Open
Abstract
In household washing machines, opportunistic pathogens such as Pseudomonas aeruginosa are present, which represent the household as a possible reservoir for clinical pathogens. Here, four novel P. aeruginosa strains, isolated from different sites of household appliances, were investigated regarding their biofilm formation. Only two isolates showed strong surface-adhered biofilm formation. In consequence of these phenotypic differences, we performed whole genome sequencing using Oxford Nanopore Technology together with Illumina MiSeq. Whole genome data were screened for the prevalence of 285 virulence- and biofilm-associated genes as well as for prophages. Linking biofilm phenotypes and parallelly appearing gene compositions, we assume a relevancy of the las quorum sensing system and the phage-encoded bacteriophage control infection gene bci, which was found on integrated phi297 DNA in all biofilm-forming isolates. Additionally, only the isolates revealing strong biofilm formation harbored the ϕCTX-like prophage Dobby, implicating a role of this prophage on biofilm formation. Investigations on clinically relevant pathogens within household appliances emphasize their adaptability to harsh environments, with high concentrations of detergents, providing greater insights into pathogenicity and underlying mechanisms. This in turn opens the possibility to map and characterize potentially relevant strains even before they appear as pathogens in society.
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Affiliation(s)
- Annika Kiel
- Department of Cell Biology, Faculty of Biology, Bielefeld University, 33615 Bielefeld, Germany
- Correspondence:
| | - Ines Creutz
- Proteome and Metabolome Research, Faculty of Biology, Bielefeld University, 33615 Bielefeld, Germany
| | - Christian Rückert
- Center for Biotechnology (CeBiTec), Bielefeld University, 33615 Bielefeld, Germany
| | - Bernhard Peter Kaltschmidt
- Department of Thin Films and Physics of Nanostructures, Center of Spinelectronic Materials and Devices, Faculty of Physics, Bielefeld University, 33615 Bielefeld, Germany
| | - Andreas Hütten
- Department of Thin Films and Physics of Nanostructures, Center of Spinelectronic Materials and Devices, Faculty of Physics, Bielefeld University, 33615 Bielefeld, Germany
| | - Karsten Niehaus
- Proteome and Metabolome Research, Faculty of Biology, Bielefeld University, 33615 Bielefeld, Germany
| | - Tobias Busche
- Center for Biotechnology (CeBiTec), Bielefeld University, 33615 Bielefeld, Germany
| | - Barbara Kaltschmidt
- Department of Cell Biology, Faculty of Biology, Bielefeld University, 33615 Bielefeld, Germany
| | - Christian Kaltschmidt
- Department of Cell Biology, Faculty of Biology, Bielefeld University, 33615 Bielefeld, Germany
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11
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Ragavendran PV, Tripathi V, Gandotra S. Structure prediction-based insights into the patatin family of Mycobacterium tuberculosis. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 36748562 DOI: 10.1099/mic.0.001270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Despite its genome sequencing more than two decades ago, the majority of the genes of Mycobacterium tuberculosis remain functionally uncharacterized. Patatins are one such class of proteins that, despite undergoing an expansion in this pathogenic species compared to their non-pathogenic cousins, remain largely unstudied. Recent advances in protein structure prediction using machine learning tools such as AlphaFold2 have provided high-confidence predicted structures for all M. tuberculosis proteins. Here we present detailed analyses of the patatin family of M. tuberculosis using AlphaFold-predicted structures, providing insights into likely modes of regulation, membrane interaction and substrate binding. Regulatory domains within this family of proteins include cyclic nucleotide binding, lid-like domains and other helical domains. Using structural homologues, we identified the likely membrane localization mechanisms and substrate-binding sites. These analyses reveal diversity in their regulatory capacity, mechanisms of membrane binding and likely length of fatty acid substrates. Together, this analysis suggests unique roles for the eight predicted patatins of M. tuberculosis.
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Affiliation(s)
- P V Ragavendran
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh- 201 002, India.,Immunology and Infectious Disease, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India, New Delhi, India
| | - Vaishnavi Tripathi
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh- 201 002, India.,Immunology and Infectious Disease, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India, New Delhi, India
| | - Sheetal Gandotra
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh- 201 002, India.,Immunology and Infectious Disease, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India, New Delhi, India
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12
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Jouault A, Saliba AM, Touqui L. Modulation of the immune response by the Pseudomonas aeruginosa type-III secretion system. Front Cell Infect Microbiol 2022; 12:1064010. [PMID: 36519135 PMCID: PMC9742435 DOI: 10.3389/fcimb.2022.1064010] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 11/15/2022] [Indexed: 11/29/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen that can cause critical cellular damage and subvert the immune response to promote its survival. Among the numerous virulence factors of P. aeruginosa, the type III secretion system (T3SS) is involved in host cell pathogenicity. Using a needle-like structure, T3SS detects eukaryotic cells and injects toxins directly into their cytosol, thus highlighting its ability to interfere with the host immune response. In this mini-review, we discuss how the T3SS and bacterial effectors secreted by this pathway not only activate the immune response but can also manipulate it to promote the establishment of P. aeruginosa infections.
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Affiliation(s)
- Albane Jouault
- Mucoviscidose: Phénotypique et Phénogénomique, Centre de Recherche Saint-Antoine, Sorbonne Universités, UPMC Univ Paris 06, INSERM, Paris, France,Département Santé Globale, Mucoviscidose et Bronchopathie Chroniques, Institut Pasteur, Paris, France,*Correspondence: Albane Jouault,
| | - Alessandra Mattos Saliba
- Department of Microbiology, Immunology and Parasitology, Faculty of Medical Sciences, Rio de Janeiro State University, Rio de Janeiro, Brazil
| | - Lhousseine Touqui
- Mucoviscidose: Phénotypique et Phénogénomique, Centre de Recherche Saint-Antoine, Sorbonne Universités, UPMC Univ Paris 06, INSERM, Paris, France,Département Santé Globale, Mucoviscidose et Bronchopathie Chroniques, Institut Pasteur, Paris, France
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13
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Liu L, Li Y, Xu Z, Chen H, Zhang J, Manion B, Liu F, Zou L, Fu ZQ, Chen G. The Xanthomonas type III effector XopAP prevents stomatal closure by interfering with vacuolar acidification. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2022; 64:1994-2008. [PMID: 35972796 DOI: 10.1111/jipb.13344] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 08/15/2022] [Indexed: 06/15/2023]
Abstract
Plant stomata close rapidly in response to a rise in the plant hormone abscisic acid (ABA) or salicylic acid (SA) and after recognition of pathogen-associated molecular patterns (PAMPs). Stomatal closure is the result of vacuolar convolution, ion efflux, and changes in turgor pressure in guard cells. Phytopathogenic bacteria secrete type III effectors (T3Es) that interfere with plant defense mechanisms, causing severe plant disease symptoms. Here, we show that the virulence and infection of Xanthomonas oryzae pv. oryzicola (Xoc), which is the causal agent of rice bacterial leaf streak disease, drastically increased in transgenic rice (Oryza sativa L.) plants overexpressing the Xoc T3E gene XopAP, which encodes a protein annotated as a lipase. We discovered that XopAP binds to phosphatidylinositol 3,5-bisphosphate (PtdIns(3,5)P2 ), a membrane phospholipid that functions in pH control in lysosomes, membrane dynamics, and protein trafficking. XopAP inhibited the acidification of vacuoles by competing with vacuolar H+ -pyrophosphatase (V-PPase) for binding to PtdIns(3,5)P2 , leading to stomatal opening. Transgenic rice overexpressing XopAP also showed inhibition of stomatal closure when challenged by Xoc infection and treatment with the PAMP flg22. Moreover, XopAP suppressed flg22-induced gene expression, reactive oxygen species burst and callose deposition in host plants, demonstrating that XopAP subverts PAMP-triggered immunity during Xoc infection. Taken together, these findings demonstrate that XopAP overcomes stomatal immunity in plants by binding to lipids.
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Affiliation(s)
- Longyu Liu
- State Key Laboratory of Microbial Metabolism/Shanghai Collaborative Innovation Center of Agri-Seeds, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China
- Department of Biological Sciences, University of South Carolina, Columbia, 29208, USA
| | - Ying Li
- State Key Laboratory of Microbial Metabolism/Shanghai Collaborative Innovation Center of Agri-Seeds, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Zhengyin Xu
- State Key Laboratory of Microbial Metabolism/Shanghai Collaborative Innovation Center of Agri-Seeds, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Huan Chen
- Department of Biological Sciences, University of South Carolina, Columbia, 29208, USA
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China
| | - Jingyi Zhang
- Department of Biological Sciences, University of South Carolina, Columbia, 29208, USA
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China
| | - Brittany Manion
- Department of Biological Sciences, University of South Carolina, Columbia, 29208, USA
| | - Fengquan Liu
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China
| | - Lifang Zou
- State Key Laboratory of Microbial Metabolism/Shanghai Collaborative Innovation Center of Agri-Seeds, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Zheng Qing Fu
- Department of Biological Sciences, University of South Carolina, Columbia, 29208, USA
| | - Gongyou Chen
- State Key Laboratory of Microbial Metabolism/Shanghai Collaborative Innovation Center of Agri-Seeds, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China
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14
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Liao C, Huang X, Wang Q, Yao D, Lu W. Virulence Factors of Pseudomonas Aeruginosa and Antivirulence Strategies to Combat Its Drug Resistance. Front Cell Infect Microbiol 2022; 12:926758. [PMID: 35873152 PMCID: PMC9299443 DOI: 10.3389/fcimb.2022.926758] [Citation(s) in RCA: 68] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Accepted: 06/09/2022] [Indexed: 11/24/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen causing nosocomial infections in severely ill and immunocompromised patients. Ubiquitously disseminated in the environment, especially in hospitals, it has become a major threat to human health due to the constant emergence of drug-resistant strains. Multiple resistance mechanisms are exploited by P. aeruginosa, which usually result in chronic infections difficult to eradicate. Diverse virulence factors responsible for bacterial adhesion and colonization, host immune suppression, and immune escape, play important roles in the pathogenic process of P. aeruginosa. As such, antivirulence treatment that aims at reducing virulence while sparing the bacterium for its eventual elimination by the immune system, or combination therapies, has significant advantages over traditional antibiotic therapy, as the former imposes minimal selective pressure on P. aeruginosa, thus less likely to induce drug resistance. In this review, we will discuss the virulence factors of P. aeruginosa, their pathogenic roles, and recent advances in antivirulence drug discovery for the treatment of P. aeruginosa infections.
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Affiliation(s)
- Chongbing Liao
- Key Laboratory of Medical Molecular Virology (Ministry of Education (MOE)/National Health Commission (NHC)/Chinese Academy of Medical Sciences (CAMS)), School of Basic Medical Science, Fudan University, Shanghai, China
| | - Xin Huang
- Key Laboratory of Medical Molecular Virology (Ministry of Education (MOE)/National Health Commission (NHC)/Chinese Academy of Medical Sciences (CAMS)), School of Basic Medical Science, Fudan University, Shanghai, China
| | - Qingxia Wang
- Key Laboratory of Medical Molecular Virology (Ministry of Education (MOE)/National Health Commission (NHC)/Chinese Academy of Medical Sciences (CAMS)), School of Basic Medical Science, Fudan University, Shanghai, China
| | - Dan Yao
- Key Laboratory of Medical Molecular Virology (Ministry of Education (MOE)/National Health Commission (NHC)/Chinese Academy of Medical Sciences (CAMS)), School of Basic Medical Science, Fudan University, Shanghai, China
| | - Wuyuan Lu
- Key Laboratory of Medical Molecular Virology (Ministry of Education (MOE)/National Health Commission (NHC)/Chinese Academy of Medical Sciences (CAMS)), School of Basic Medical Science, Fudan University, Shanghai, China.,Shanghai Institute of Infectious Disease and Biosecurity, School of Public Health, Fudan University, Shanghai, China
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15
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Constantino-Teles P, Jouault A, Touqui L, Saliba AM. Role of Host and Bacterial Lipids in Pseudomonas aeruginosa Respiratory Infections. Front Immunol 2022; 13:931027. [PMID: 35860265 PMCID: PMC9289105 DOI: 10.3389/fimmu.2022.931027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 06/07/2022] [Indexed: 11/13/2022] Open
Abstract
The opportunistic pathogen Pseudomonas aeruginosa is one of the most common agents of respiratory infections and has been associated with high morbidity and mortality rates. The ability of P. aeruginosa to cause severe respiratory infections results from the coordinated action of a variety of virulence factors that promote bacterial persistence in the lungs. Several of these P. aeruginosa virulence mechanisms are mediated by bacterial lipids, mainly lipopolysaccharide, rhamnolipid, and outer membrane vesicles. Other mechanisms arise from the activity of P. aeruginosa enzymes, particularly ExoU, phospholipase C, and lipoxygenase A, which modulate host lipid signaling pathways. Moreover, host phospholipases, such as cPLA2α and sPLA2, are also activated during the infectious process and play important roles in P. aeruginosa pathogenesis. These mechanisms affect key points of the P. aeruginosa-host interaction, such as: i) biofilm formation that contributes to bacterial colonization and survival, ii) invasion of tissue barriers that allows bacterial dissemination, iii) modulation of inflammatory responses, and iv) escape from host defenses. In this mini-review, we present the lipid-based mechanism that interferes with the establishment of P. aeruginosa in the lungs and discuss how bacterial and host lipids can impact the outcome of P. aeruginosa respiratory infections.
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Affiliation(s)
- Pamella Constantino-Teles
- Department of Microbiology, Immunology and Parasitology, Faculty of Medical Sciences, Rio de Janeiro State University, Rio de Janeiro, Brazil
| | - Albane Jouault
- Sorbonne Université, Centre de Recherche Saint-Antoine, Inserm, Institut Pasteur, Mucoviscidose et Bronchopathies Chroniques, Département Santé Globale, Paris, France
| | - Lhousseine Touqui
- Sorbonne Université, Centre de Recherche Saint-Antoine, Inserm, Institut Pasteur, Mucoviscidose et Bronchopathies Chroniques, Département Santé Globale, Paris, France
| | - Alessandra Mattos Saliba
- Department of Microbiology, Immunology and Parasitology, Faculty of Medical Sciences, Rio de Janeiro State University, Rio de Janeiro, Brazil
- *Correspondence: Alessandra Mattos Saliba,
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Sid Ahmed MA, Abdel Hadi H, Abu Jarir S, Ahmad Khan F, Arbab MA, Hamid JM, Alyazidi MA, Al-Maslamani MA, Skariah S, Sultan AA, Al Khal AL, Söderquist B, Ibrahim EB, Jass J, Ziglam H. Prevalence and microbiological and genetic characteristics of multidrug-resistant Pseudomonas aeruginosa over three years in Qatar. ANTIMICROBIAL STEWARDSHIP & HEALTHCARE EPIDEMIOLOGY : ASHE 2022; 2:e96. [PMID: 36483382 PMCID: PMC9726487 DOI: 10.1017/ash.2022.226] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 04/13/2022] [Accepted: 04/14/2022] [Indexed: 06/17/2023]
Abstract
OBJECTIVES Antimicrobial resistance (AMR) is a global priority with significant clinical and economic consequences. Multidrug-resistant (MDR) Pseudomonas aeruginosa is one of the major pathogens associated with significant morbidity and mortality. In healthcare settings, the evaluation of prevalence, microbiological characteristics, as well as mechanisms of resistance is of paramount importance to overcome associated challenges. METHODS Consecutive clinical specimens of P. aeruginosa were collected prospectively from 5 acute-care and specialized hospitals between October 2014 and September 2017, including microbiological, clinical characteristics and outcomes. Identification and antimicrobial susceptibility test were performed using the BD Phoenix identification and susceptibility testing system, matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS), and minimum inhibitory concentration (MIC) test strips. Overall, 78 selected MDR P. aeruginosa isolates were processed for whole-genome sequencing (WGS). RESULTS The overall prevalence of MDR P. aeruginosa isolates was 5.9% (525 of 8,892) and showed a decreasing trend; 95% of cases were hospital acquired and 44.8% were from respiratory samples. MDR P. aeruginosa demonstrated >86% resistance to cefepime, ciprofloxacin, meropenem, and piperacillin-tazobactam but 97.5% susceptibility to colistin. WGS revealed 29 different sequence types: 20.5% ST235, 10.3% ST357, 7.7% ST389, and 7.7% ST1284. ST233 was associated with bloodstream infections and increased 30-day mortality. All ST389 isolates were obtained from patients with cystic fibrosis. Encoded exotoxin genes were detected in 96.2% of isolates. CONCLUSIONS MDR P. aeruginosa isolated from clinical specimens from Qatar has significant resistance to most agents, with a decreasing trend that should be explored further. Genomic analysis revealed the dominance of 5 main clonal clusters associated with mortality and bloodstream infections. Microbiological and genomic monitoring of MDR P. aeruginosa has enhanced our understanding of AMR in Qatar.
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Affiliation(s)
- Mazen A. Sid Ahmed
- Microbiology Division, Department of Laboratory Medicine and Pathology, Hamad Medical Corporation, Doha, Qatar
- The Life Science Centre – Biology, School of Science and Technology, Örebro University, Örebro, Sweden
| | - Hamad Abdel Hadi
- Department of Infectious Diseases, Communicable Diseases Center, Hamad Medical Corporation, Doha, Qatar
| | - Sulieman Abu Jarir
- Department of Infectious Diseases, Communicable Diseases Center, Hamad Medical Corporation, Doha, Qatar
| | - Faisal Ahmad Khan
- The Life Science Centre – Biology, School of Science and Technology, Örebro University, Örebro, Sweden
| | | | - Jemal M. Hamid
- Microbiology Division, Department of Laboratory Medicine and Pathology, Hamad Medical Corporation, Doha, Qatar
| | - Mohammed A. Alyazidi
- Microbiology Division, Department of Laboratory Medicine and Pathology, Hamad Medical Corporation, Doha, Qatar
| | - Muna A. Al-Maslamani
- Department of Infectious Diseases, Communicable Diseases Center, Hamad Medical Corporation, Doha, Qatar
| | - Sini Skariah
- Department of Microbiology and Immunology, Weill Cornell Medicine – Qatar, Doha, Qatar
| | - Ali A. Sultan
- Department of Microbiology and Immunology, Weill Cornell Medicine – Qatar, Doha, Qatar
| | - Abdul Latif Al Khal
- Department of Infectious Diseases, Communicable Diseases Center, Hamad Medical Corporation, Doha, Qatar
| | - Bo Söderquist
- School of Medical Sciences, Faculty of Medicine and Health, Orebro University, Orebro, Sweden
| | - Emad Bashir Ibrahim
- Microbiology Division, Department of Laboratory Medicine and Pathology, Hamad Medical Corporation, Doha, Qatar
- Biomedical Research Centre, Qatar University, Doha, Qatar
| | - Jana Jass
- The Life Science Centre – Biology, School of Science and Technology, Örebro University, Örebro, Sweden
| | - Hisham Ziglam
- Department of Infectious Diseases, Communicable Diseases Center, Hamad Medical Corporation, Doha, Qatar
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17
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Hardy KS, Tuckey AN, Housley NA, Andrews J, Patel M, Al-Mehdi AB, Barrington RA, Cassel SL, Sutterwala FS, Audia JP. The Pseudomonas aeruginosa Type III Secretion System Exoenzyme Effector ExoU Induces Mitochondrial Damage in a Murine Bone Marrow-Derived Macrophage Infection Model. Infect Immun 2022; 90:e0047021. [PMID: 35130452 PMCID: PMC8929383 DOI: 10.1128/iai.00470-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 01/18/2022] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas aeruginosa is a Gram-negative, opportunistic pathogen that causes nosocomial pneumonia, urinary tract infections, and bacteremia. A hallmark of P. aeruginosa pathogenesis is disruption of host cell function by the type III secretion system (T3SS) and its cognate exoenzyme effectors. The T3SS effector ExoU is phospholipase A2 (PLA2) that targets the host cell plasmalemmal membrane to induce cytolysis and is an important virulence factor that mediates immune avoidance. In addition, ExoU has been shown to subvert the host inflammatory response in a noncytolytic manner. In primary bone marrow-derived macrophages (BMDMs), P. aeruginosa infection is sensed by the nucleotide-binding domain containing leucine-rich repeats-like receptor 4 (NLRC4) inflammasome, which triggers caspase-1 activation and inflammation. ExoU transiently inhibits NLRC4 inflammasome-mediated activation of caspase-1 and its downstream target, interleukin 1β (IL-1β), to suppress activation of inflammation. In the present study, we sought to identify additional noncytolytic virulence functions for ExoU and discovered an unexpected association between ExoU, host mitochondria, and NLRC4. We show that infection of BMDMs with P. aeruginosa strains expressing ExoU elicited mitochondrial oxidative stress. In addition, mitochondria and mitochondrion-associated membrane fractions enriched from infected cells exhibited evidence of autophagy activation, indicative of damage. The observation that ExoU elicited mitochondrial stress and damage suggested that ExoU may also associate with mitochondria during infection. Indeed, ExoU phospholipase A2 enzymatic activity was present in enriched mitochondria and mitochondrion-associated membrane fractions isolated from P. aeruginosa-infected BMDMs. Intriguingly, enriched mitochondria and mitochondrion-associated membrane fractions isolated from infected Nlrc4 homozygous knockout BMDMs displayed significantly lower levels of ExoU enzyme activity, suggesting that NLRC4 plays a role in the ExoU-mitochondrion association. These observations prompted us to assay enriched mitochondria and mitochondrion-associated membrane fractions for NLRC4, caspase-1, and IL-1β. NLRC4 and pro-caspase-1 were detected in enriched mitochondria and mitochondrion-associated membrane fractions isolated from noninfected BMDMs, and active caspase-1 and active IL-1β were detected in response to P. aeruginosa infection. Interestingly, ExoU inhibited mitochondrion-associated caspase-1 and IL-1β activation. The implications of ExoU-mediated effects on mitochondria and the NLRC4 inflammasome during P. aeruginosa infection are discussed.
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Affiliation(s)
- Kierra S. Hardy
- Department of Microbiology and Immunology, University of South Alabama College of Medicine, Mobile, Alabama, USA
- Center for Lung Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - Amanda N. Tuckey
- Department of Microbiology and Immunology, University of South Alabama College of Medicine, Mobile, Alabama, USA
- Center for Lung Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - Nicole A. Housley
- Department of Microbiology and Immunology, University of South Alabama College of Medicine, Mobile, Alabama, USA
- Center for Lung Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - Joel Andrews
- Mitchell Cancer Institute, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - Mita Patel
- Department of Pharmcology, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - Abu-Bakr Al-Mehdi
- Department of Pharmcology, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - Robert A. Barrington
- Department of Microbiology and Immunology, University of South Alabama College of Medicine, Mobile, Alabama, USA
- Center for Lung Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - Suzanne L. Cassel
- Women’s Guild Lung Institute, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Fayyaz S. Sutterwala
- Women’s Guild Lung Institute, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Jonathon P. Audia
- Department of Microbiology and Immunology, University of South Alabama College of Medicine, Mobile, Alabama, USA
- Center for Lung Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
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18
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Naito Y, Kato H, Zhou L, Sugita S, He H, Zheng J, Hao Q, Sawa T, Lee JW. Therapeutic Effects of Hyaluronic Acid Against Cytotoxic Extracellular Vesicles Released During Pseudomonas Aeruginosa Pneumonia. Shock 2022; 57:408-416. [PMID: 34387224 PMCID: PMC8840981 DOI: 10.1097/shk.0000000000001846] [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] [Indexed: 11/26/2022]
Abstract
ABSTRACT Extracellular vesicles (EVs) have now been recognized as important mediators of cellular communication during injury and repair. We previously found that plasma EVs isolated from ex vivo perfused human lungs injured with Escherichia coli bacterial pneumonia were inflammatory, and exogenous administration of high molecular weight (HMW) hyaluronic acid (HA) as therapy bound to these EVs, decreasing inflammation and injury. In the current study, we studied the role of EVs released during severe Pseudomonas aeruginosa (PA) pneumonia in mice and determined whether intravenous administration of exogenous HMW HA would have therapeutic effects against the bacterial pneumonia. EVs were collected from the bronchoalveolar lavage fluid (BALF) of mice infected with PA103 by ultracentrifugation and analyzed by NanoSight and flow cytometry. In a cytotoxicity assay, administration of EVs released from infected mice (I-EVs) decreased the viability of A549 cells compared to EV isolated from sham control mice (C-EVs). Either exogenous HMW HA or an anti-CD44 antibody, when co-incubated with I-EVs, significantly improved the viability of the A549 cells. In mice with PA103 pneumonia, administration of HMW HA improved pulmonary edema and bacterial count in the lungs and decreased TNF-α and caspase-3 levels in the supernatant of lung homogenates. In conclusion, EVs isolated from BALF of mice with P. aeruginosa pneumonia were cytotoxic and inflammatory, and intravenous HMW HA administration was protective against P. aeruginosa pneumonia.
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Affiliation(s)
- Yoshifumi Naito
- Department of Anesthesiology, Kyoto Prefectural University of Medicine, Japan
| | - Hideya Kato
- Department of Anesthesiology, Kyoto Prefectural University of Medicine, Japan
| | - Li Zhou
- Department of Anesthesiology, University of California San Francisco, San Francisco, California
| | - Shinji Sugita
- Department of Anesthesiology, University of California San Francisco, San Francisco, California
| | - Hongli He
- Department of Anesthesiology, University of California San Francisco, San Francisco, California
| | - Justin Zheng
- Department of Anesthesiology, University of California San Francisco, San Francisco, California
| | - Qi Hao
- Department of Anesthesiology, University of California San Francisco, San Francisco, California
| | - Teiji Sawa
- Department of Anesthesiology, Kyoto Prefectural University of Medicine, Japan
| | - Jae-Woo Lee
- Department of Anesthesiology, University of California San Francisco, San Francisco, California
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19
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Hardy KS, Tuckey AN, Renema P, Patel M, Al-Mehdi AB, Spadafora D, Schlumpf CA, Barrington RA, Alexeyev MF, Stevens T, Pittet JF, Wagener BM, Simmons JD, Alvarez DF, Audia JP. ExoU Induces Lung Endothelial Cell Damage and Activates Pro-Inflammatory Caspase-1 during Pseudomonas aeruginosa Infection. Toxins (Basel) 2022; 14:toxins14020152. [PMID: 35202178 PMCID: PMC8878379 DOI: 10.3390/toxins14020152] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 02/07/2022] [Accepted: 02/11/2022] [Indexed: 12/24/2022] Open
Abstract
The Gram-negative, opportunistic pathogen Pseudomonas aeruginosa utilizes a type III secretion system to inject exoenzyme effectors into a target host cell. Of the four best-studied exoenzymes, ExoU causes rapid cell damage and death. ExoU is a phospholipase A2 (PLA2) that hydrolyses host cell membranes, and P. aeruginosa strains expressing ExoU are associated with poor outcomes in critically ill patients with pneumonia. While the effects of ExoU on lung epithelial and immune cells are well studied, a role for ExoU in disrupting lung endothelial cell function has only recently emerged. Lung endothelial cells maintain a barrier to fluid and protein flux into tissue and airspaces and regulate inflammation. Herein, we describe a pulmonary microvascular endothelial cell (PMVEC) culture infection model to examine the effects of ExoU. Using characterized P. aeruginosa strains and primary clinical isolates, we show that strains expressing ExoU disrupt PMVEC barrier function by causing substantial PMVEC damage and lysis, in a PLA2-dependent manner. In addition, we show that strains expressing ExoU activate the pro-inflammatory caspase-1, in a PLA2-dependent manner. Considering the important roles for mitochondria and oxidative stress in regulating inflammatory responses, we next examined the effects of ExoU on reactive oxygen species production. Infection of PMVECs with P. aeruginosa strains expressing ExoU triggered a robust oxidative stress compared to strains expressing other exoenzyme effectors. We also provide evidence that, intriguingly, ExoU PLA2 activity was detectable in mitochondria and mitochondria-associated membrane fractions isolated from P. aeruginosa-infected PMVECs. Interestingly, ExoU-mediated activation of caspase-1 was partially inhibited by reactive oxygen species scavengers. Together, these data suggest ExoU exerts pleiotropic effects on PMVEC function during P. aeruginosa infection that may inhibit endothelial barrier and inflammatory functions.
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Affiliation(s)
- Kierra S. Hardy
- Department of Microbiology and Immunology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; (K.S.H.); (A.N.T.); (C.A.S.); (R.A.B.)
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; (P.R.); (M.P.); (A.-B.A.-M.); (M.F.A.); (T.S.); (J.D.S.); (D.F.A.)
- Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Amanda N. Tuckey
- Department of Microbiology and Immunology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; (K.S.H.); (A.N.T.); (C.A.S.); (R.A.B.)
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; (P.R.); (M.P.); (A.-B.A.-M.); (M.F.A.); (T.S.); (J.D.S.); (D.F.A.)
| | - Phoibe Renema
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; (P.R.); (M.P.); (A.-B.A.-M.); (M.F.A.); (T.S.); (J.D.S.); (D.F.A.)
- Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA
- Department of Biomedical Sciences, College of Allied Health, University of South Alabama Mobile, Mobile, AL 36688, USA
| | - Mita Patel
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; (P.R.); (M.P.); (A.-B.A.-M.); (M.F.A.); (T.S.); (J.D.S.); (D.F.A.)
- Department of Pharmacology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA
| | - Abu-Bakr Al-Mehdi
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; (P.R.); (M.P.); (A.-B.A.-M.); (M.F.A.); (T.S.); (J.D.S.); (D.F.A.)
- Department of Pharmacology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA
| | - Domenico Spadafora
- Flow Cytometry Core Lab, College of Medicine, University of South Alabama, Mobile, AL 36688, USA;
| | - Cody A. Schlumpf
- Department of Microbiology and Immunology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; (K.S.H.); (A.N.T.); (C.A.S.); (R.A.B.)
| | - Robert A. Barrington
- Department of Microbiology and Immunology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; (K.S.H.); (A.N.T.); (C.A.S.); (R.A.B.)
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; (P.R.); (M.P.); (A.-B.A.-M.); (M.F.A.); (T.S.); (J.D.S.); (D.F.A.)
- Flow Cytometry Core Lab, College of Medicine, University of South Alabama, Mobile, AL 36688, USA;
| | - Mikhail F. Alexeyev
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; (P.R.); (M.P.); (A.-B.A.-M.); (M.F.A.); (T.S.); (J.D.S.); (D.F.A.)
- Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA
| | - Troy Stevens
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; (P.R.); (M.P.); (A.-B.A.-M.); (M.F.A.); (T.S.); (J.D.S.); (D.F.A.)
- Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA
| | - Jean-Francois Pittet
- Department of Anesthesiology and Perioperative Medicine, Birmingham School of Medicine, University of Alabama, Birmingham, AL 35294, USA; (J.-F.P.); (B.M.W.)
| | - Brant M. Wagener
- Department of Anesthesiology and Perioperative Medicine, Birmingham School of Medicine, University of Alabama, Birmingham, AL 35294, USA; (J.-F.P.); (B.M.W.)
| | - Jon D. Simmons
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; (P.R.); (M.P.); (A.-B.A.-M.); (M.F.A.); (T.S.); (J.D.S.); (D.F.A.)
- Department of Pharmacology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA
- Department of Surgery, College of Medicine, University of South Alabama, Mobile, AL 36688, USA
| | - Diego F. Alvarez
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; (P.R.); (M.P.); (A.-B.A.-M.); (M.F.A.); (T.S.); (J.D.S.); (D.F.A.)
- Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA
- Department of Physiology and Pharmacology, College of Osteopathic Medicine, Sam Houston State University, Conroe, TX 77304, USA
| | - Jonathon P. Audia
- Department of Microbiology and Immunology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; (K.S.H.); (A.N.T.); (C.A.S.); (R.A.B.)
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; (P.R.); (M.P.); (A.-B.A.-M.); (M.F.A.); (T.S.); (J.D.S.); (D.F.A.)
- Correspondence:
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Doumith M, Alhassinah S, Alswaji A, Alzayer M, Alrashidi E, Okdah L, Aljohani S, Balkhy HH, Alghoribi MF. Genomic Characterization of Carbapenem-Non-susceptible Pseudomonas aeruginosa Clinical Isolates From Saudi Arabia Revealed a Global Dissemination of GES-5-Producing ST235 and VIM-2-Producing ST233 Sub-Lineages. Front Microbiol 2022; 12:765113. [PMID: 35069471 PMCID: PMC8770977 DOI: 10.3389/fmicb.2021.765113] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 12/13/2021] [Indexed: 11/21/2022] Open
Abstract
Carbapenem-resistant P. aeruginosa has become a major clinical problem due to limited treatment options. However, studies assessing the trends in the molecular epidemiology and mechanisms of antibiotic resistance in this pathogen are lacking in Saudi Arabia. Here, we reported the genome characterization in a global context of carbapenem non-susceptible clinical isolates from a nationally representative survey. The antibiotic resistance profiles of the isolates (n = 635) collected over 14 months between March 2018 and April 2019 from different geographical regions of Saudi Arabia showed resistance rates to relevant β-lactams, aminoglycosides and quinolones ranging between 6.93 and 27.56%. Overall, 22.52% (143/635) of the isolates exhibited resistance to both imipenem and meropenem that were mainly explained by porin loss and efflux overexpression. However, 18.18% of resistant isolates harbored genes encoding GES (69.23%), VIM (23.07%), NDM (3.85%) or OXA-48-like (3.85%) carbapenemases. Most common GES-positive isolates produced GESs −5, −15 or −1 and all belonged to ST235 whereas the VIM-positive isolates produced mainly VIM-2 and belonged to ST233 or ST257. GES and VIM producers were detected at different sampling periods and in different surveyed regions. Interestingly, a genome-wide comparison revealed that the GES-positive ST235 and VIM-2-positive ST233 genomes sequenced in this study and those available through public databases from various locations worldwide, constituted each a phylogenetically closely related sub-lineage. Profiles of virulence determinants, antimicrobial resistance genes and associated mobile elements confirmed relatedness within each of these two different sub-lineages. Sequence analysis located the blaGES gene in nearly all studied genomes (95.4%) in the same integrative conjugative element that also harbored the acc(6′)-Ib, aph(3′)-XV, aadA6, sul1, tet(G), and catB resistance genes while blaVIM–2 in most (98.89%) ST233-positive genomes was co-located with aac(6′)-I1, dfrB-5, and aac(3′)-Id in the same class I integron. The study findings revealed the global spread of GES-5 ST235 and VIM-2 ST233 sub-lineages and highlighted the importance of routine detection of rare β-lactamases.
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Affiliation(s)
- Michel Doumith
- Infectious Diseases Research Department, King Abdullah International Medical Research Center, Riyadh, Saudi Arabia.,King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Sarah Alhassinah
- Infectious Diseases Research Department, King Abdullah International Medical Research Center, Riyadh, Saudi Arabia.,King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Abdulrahman Alswaji
- Infectious Diseases Research Department, King Abdullah International Medical Research Center, Riyadh, Saudi Arabia.,King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Maha Alzayer
- Infectious Diseases Research Department, King Abdullah International Medical Research Center, Riyadh, Saudi Arabia.,King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Essa Alrashidi
- Infectious Diseases Research Department, King Abdullah International Medical Research Center, Riyadh, Saudi Arabia.,King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Liliane Okdah
- Infectious Diseases Research Department, King Abdullah International Medical Research Center, Riyadh, Saudi Arabia.,King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Sameera Aljohani
- Infectious Diseases Research Department, King Abdullah International Medical Research Center, Riyadh, Saudi Arabia.,King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia.,Department of Pathology and Laboratory Medicine, King Abdulaziz Medical City (KAMC), Ministry of National Guard Health Affairs (MNGHA), Riyadh, Saudi Arabia
| | | | | | - Majed F Alghoribi
- Infectious Diseases Research Department, King Abdullah International Medical Research Center, Riyadh, Saudi Arabia.,King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia.,Department of Pathology and Laboratory Medicine, King Abdulaziz Medical City (KAMC), Ministry of National Guard Health Affairs (MNGHA), Riyadh, Saudi Arabia
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21
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Chamberlain K, Johnson M, Reid TE, Springer TI. Utilizing in silico and in vitro methods to identify possible binding sites of a novel ligand against Pseudomonas aeruginosa phospholipase toxin ExoU. Biochem Biophys Rep 2022; 29:101188. [PMID: 34984240 PMCID: PMC8693347 DOI: 10.1016/j.bbrep.2021.101188] [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] [Received: 10/22/2021] [Revised: 12/07/2021] [Accepted: 12/11/2021] [Indexed: 11/25/2022] Open
Abstract
Multi-drug resistant infections caused by the opportunistic pathogen, Pseudomonas aeruginosa (P. aeruginosa), are a continuing problem that contribute to morbidity and mortality in immunocompromised hosts such as cystic fibrosis (CF), wound and burn patients. The bacterial toxin ExoU is one of four potent toxins that P. aeruginosa secretes into the epithelial cells of hosts. In this study, NMR Saturation Transfer Difference (STD) and in silico Schrödinger Computational Modeling were used to identify a possible binding site of a novel ligand methoctramine targeting ExoU. Future project goals will be to design a structure activity relationship (SAR) study of methoctramine and ExoU and lead to a new drug solving ExoU toxicity P. aeruginosa exerts in the clinical environment. STD-NMR identified a weak binding molecule for ExoU. Schrödinger's SiteMap tool to identify potential binding sites of methoctramine to ExoU. Positively charged protonated amines on methoctramine allows for multiple salt bridge and H-bond interactions. Top ranked druggable site aligns and corresponds to ExoU C-terminus region.
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Affiliation(s)
- Krista Chamberlain
- Pharmaceutical Sciences Department, School of Pharmacy, Concordia University Wisconsin, Mequon, WI, 53097, USA
| | - Mya Johnson
- Harvard Faculty of Arts and Science, School of Engineering and Applied Sciences, 150 Western Ave, Boston, MA, 02134, USA
| | - Terry-Elinor Reid
- Pharmaceutical Sciences Department, School of Pharmacy, Concordia University Wisconsin, Mequon, WI, 53097, USA
| | - Tzvia I Springer
- Pharmaceutical Sciences Department, School of Pharmacy, Concordia University Wisconsin, Mequon, WI, 53097, USA
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22
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Shen E, Yang J, Tsuei KSC. The role of Type III secretion system in the pathogenesis of Pseudomonas aeruginosa microbial keratitis. Tzu Chi Med J 2022; 34:8-14. [PMID: 35233350 PMCID: PMC8830546 DOI: 10.4103/tcmj.tcmj_47_21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 03/11/2021] [Accepted: 03/17/2021] [Indexed: 11/22/2022] Open
Abstract
Pseudomonas aeruginosa is the most commonly isolated Gram-negative pathogen causing sight-threatening microbial keratitis (MK). Contact lens wear is the most significant risk factor associated with pseudomonal MK. Understanding the pathogenesis of MK due to P. aeruginosa and its interactions with contact lenses is crucial in preventing these often rapidly progressive and highly antibiotic-resistant infections. Bacterial virulence factor Type III secretion system (T3SS) has significant interplays between contact lens material, antibiotic sensitivity, disinfectant selectivity, and bacterial cell invasion. Depending on the T3SS exotoxins produced, P. aeruginosa strains are divided into cytotoxic or invasive strains. Cytotoxic strains are relatively resistant to commercial disinfectants, while invasive strains are more antibiotic resistant. Therefore, contact lens wearers are more predisposed to cytotoxic P. aeruginosa infections, and patients with trauma or previous surgery are more prone to infection by invasive strains. Previous studies with mutant P. aeruginosa strains unable to produce T3SS exotoxins were more susceptible to disinfectants and less able to adhere to soft contact lenses, indicating an essential role of T3SS in bacterial virulence. Invasion of P. aeruginosa intracellularly was found to be associated with control of scaffold protein IQ-domain GTPase-activating protein 1 (IQGAP1) and human corneal epithelial cell tight junctions. Knockdown of IQGAP1 strengthened tight junctions that prevented intracellular survival of invasive P. aeruginosa strains and enhanced corneal epithelial cell survival. These novel findings of the vital role of T3SS in the pathogenesis of pseudomonal MKs will provide new guidelines in both prevention and treatment of this common eye-blinding infection.
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23
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Hardy KS, Tessmer MH, Frank DW, Audia JP. Perspectives on the Pseudomonas aeruginosa Type III Secretion System Effector ExoU and Its Subversion of the Host Innate Immune Response to Infection. Toxins (Basel) 2021; 13:880. [PMID: 34941717 PMCID: PMC8708460 DOI: 10.3390/toxins13120880] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 11/19/2021] [Accepted: 12/04/2021] [Indexed: 12/02/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic, Gram-negative pathogen and an important cause of hospital acquired infections, especially in immunocompromised patients. Highly virulent P. aeruginosa strains use a type III secretion system (T3SS) to inject exoenzyme effectors directly into the cytoplasm of a target host cell. P. aeruginosa strains that express the T3SS effector, ExoU, associate with adverse outcomes in critically ill patients with pneumonia, owing to the ability of ExoU to rapidly damage host cell membranes and subvert the innate immune response to infection. Herein, we review the structure, function, regulation, and virulence characteristics of the T3SS effector ExoU, a highly cytotoxic phospholipase A2 enzyme.
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Affiliation(s)
- Kierra S. Hardy
- Department of Microbiology and Immunology, University of South Alabama College of Medicine, Mobile, AL 36608, USA;
- Center for Lung Biology, University of South Alabama College of Medicine, Mobile, AL 36608, USA
- Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Maxx H. Tessmer
- Department of Chemistry, University of Washington, Seattle, WA 98195, USA;
| | - Dara W. Frank
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Jonathon P. Audia
- Department of Microbiology and Immunology, University of South Alabama College of Medicine, Mobile, AL 36608, USA;
- Center for Lung Biology, University of South Alabama College of Medicine, Mobile, AL 36608, USA
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24
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Cai W, Arias CR. Deciphering the Molecular Basis for Attenuation of Flavobacterium columnare Strain Fc1723 Used as Modified Live Vaccine against Columnaris Disease. Vaccines (Basel) 2021; 9:vaccines9111370. [PMID: 34835301 PMCID: PMC8622145 DOI: 10.3390/vaccines9111370] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 11/17/2021] [Accepted: 11/18/2021] [Indexed: 11/16/2022] Open
Abstract
Vaccines are widely employed in aquaculture to prevent bacterial infections, but their use by the U.S. catfish industry is very limited. One of the main diseases affecting catfish aquaculture is columnaris disease, caused by the bacterial pathogen Flavobacterium columnare. In 2011, a modified-live vaccine against columnaris disease was developed by selecting mutants that were resistant to rifampin. The previous study has suggested that this vaccine is stable, safe, and effective, but the mechanisms that resulted in attenuation remained uncharacterized. To understand the molecular basis for attenuation, a comparative genomic analysis was conducted to identify specific point mutations. The PacBio RS long-read sequencing platform was used to obtain draft genomes of the mutant attenuated strain (Fc1723) and the parent virulent strain (FcB27). Sequence-based genome comparison identified 16 single nucleotide polymorphisms (SNP) unique to the mutant. Genes that contained mutations were involved in rifampin resistance, gliding motility, DNA transcription, toxin secretion, and extracellular protease synthesis. The results also found that the vaccine strain formed biofilm at a significantly lower rate than the parent strain. These observations suggested that the rifampin-resistant phenotype and the associated attenuation of the vaccine strain result from the altered activity of RNA polymerase (RpoB) and possible disrupted protein secretion systems.
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Affiliation(s)
- Wenlong Cai
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong 999077, China
- Correspondence:
| | - Covadonga R. Arias
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36832, USA;
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25
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Irum S, Naz K, Ullah N, Mustafa Z, Ali A, Arslan M, Khalid K, Andleeb S. Antimicrobial Resistance and Genomic Characterization of Six New Sequence Types in Multidrug-Resistant Pseudomonas aeruginosa Clinical Isolates from Pakistan. Antibiotics (Basel) 2021; 10:antibiotics10111386. [PMID: 34827324 PMCID: PMC8615273 DOI: 10.3390/antibiotics10111386] [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] [Received: 07/15/2021] [Revised: 08/06/2021] [Accepted: 08/13/2021] [Indexed: 01/13/2023] Open
Abstract
Pseudomonas aeruginosa (P. aeruginosa) is a major bacterial pathogen associated with a variety of infections with high mortality rates. Most of the clinical P. aeruginosa isolates belong to a limited number of genetic subgroups characterized by multiple housekeeping genes’ sequences (usually 5–7) through the Multi-Locus Sequence Typing (MLST) scheme. The emergence and dissemination of novel multidrug-resistant (MDR) sequence types (ST) in P. aeruginosa pose serious clinical concerns. We performed whole-genome sequencing on a cohort (n = 160) of MDR P. aeruginosa isolates collected from a tertiary care hospital lab in Pakistan and found six isolates belonging to six unique MLST allelic profiles. The genomes were submitted to the PubMLST database and new ST numbers (ST3493, ST3494, ST3472, ST3489, ST3491, and ST3492) were assigned to the respective allele combinations. MLST and core-genome-based phylogenetic analysis confirmed the divergence of these isolates and positioned them in separate branches. Analysis of the resistome of the new STs isolates revealed the presence of genes blaOXA-50, blaPAO, blaPDC, blaVIM-2, aph(3′)-IIb, aac(6′)-II, aac(3)-Id, fosA, catB7, dfrB2, crpP, merP and a number of missense and frame-shift mutations in chromosomal genes conferring resistance to various antipseudomonal antibiotics. The exoS, exoT, pvdE, rhlI, rhlR, lasA, lasB, lasI, and lasR genes were the most prevalent virulence-related genes among the new ST isolates. The different genotypic features revealed the adaptation of these new clones to a variety of infections by various mutations in genes affecting antimicrobial resistance, quorum sensing and biofilm formation. Close monitoring of these antibiotic-resistant pathogens and surveillance mechanisms needs to be adopted to reduce their spread to the healthcare facilities of Pakistan. We believe that these strains can be used as reference strains for future comparative analysis of isolates belonging to the same STs.
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Affiliation(s)
- Sidra Irum
- Department of Industrial Biotechnology, Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences & Technology (NUST), Islamabad 44000, Pakistan; (S.I.); (K.N.); (N.U.); (Z.M.); (A.A.); (K.K.)
| | - Kanwal Naz
- Department of Industrial Biotechnology, Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences & Technology (NUST), Islamabad 44000, Pakistan; (S.I.); (K.N.); (N.U.); (Z.M.); (A.A.); (K.K.)
| | - Nimat Ullah
- Department of Industrial Biotechnology, Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences & Technology (NUST), Islamabad 44000, Pakistan; (S.I.); (K.N.); (N.U.); (Z.M.); (A.A.); (K.K.)
| | - Zeeshan Mustafa
- Department of Industrial Biotechnology, Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences & Technology (NUST), Islamabad 44000, Pakistan; (S.I.); (K.N.); (N.U.); (Z.M.); (A.A.); (K.K.)
| | - Amjad Ali
- Department of Industrial Biotechnology, Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences & Technology (NUST), Islamabad 44000, Pakistan; (S.I.); (K.N.); (N.U.); (Z.M.); (A.A.); (K.K.)
| | - Muhammad Arslan
- Pakistan Institute of Medical Sciences (PIMS), Islamabad 44000, Pakistan;
| | - Kashaf Khalid
- Department of Industrial Biotechnology, Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences & Technology (NUST), Islamabad 44000, Pakistan; (S.I.); (K.N.); (N.U.); (Z.M.); (A.A.); (K.K.)
| | - Saadia Andleeb
- Department of Industrial Biotechnology, Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences & Technology (NUST), Islamabad 44000, Pakistan; (S.I.); (K.N.); (N.U.); (Z.M.); (A.A.); (K.K.)
- Correspondence: or
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26
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Yang H, Wang Y, Yang Q, Fan H, Wang L, Zhang T, Li Z, Liu G, Zhao P, Wu H, Dong J, Liang W. A Rapid and Sensitive Detection Method for Pseudomonas aeruginosa Using Visualized Recombinase Polymerase Amplification and Lateral Flow Strip Technology. Front Cell Infect Microbiol 2021; 11:698929. [PMID: 34595129 PMCID: PMC8478171 DOI: 10.3389/fcimb.2021.698929] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 08/16/2021] [Indexed: 11/25/2022] Open
Abstract
Pseudomonas aeruginosa is a common opportunistic pathogen that causes acute nosocomial necrotizing pneumonia and is the predominant source of chronic lung infections in patients with the genetic disorder cystic fibrosis. Early diagnosis in infected patients and monitoring P. aeruginosa contamination is therefore of great importance in controlling disease spread and development with timely drugs intervention treatment and cut off infection source. Traditional culture-biochemical methods are time consuming and highly dependent on technicians and expensive instruments. To address these challenges, the present study aimed to develop a rapid, sensitive, and specific, on-site detection method for P. aeruginosa based on recombinase polymerase amplification (RPA) combined with lateral flow strip (LFS) technology. The experimental process included screening and modification of primer and probe sets targeting the unique virulence gene elastase B (lasB); specificity detection in 29 strains of P. aeruginosa and 23 closely-related pathogenic bacteria; sensitivity measurements with gradient-diluted P. aeruginosa genomic DNA and probit regression analysis; and clinical application evaluation using 574 patients samples and calculating coincidence rate and kappa index value in comparison with the culture-biochemical method. The P. aeruginosa RPA-LFS assay could complete the amplification process at 37°C constant temperature within 30 min and results could be visualized by the naked eye within 10 min on LFS. The assay displayed high sensitivity with a limit of detection of 3.05 CFU/reaction. It also demonstrated high specificity by showing no cross reaction with other pathogenic bacteria, and rapidness by being completed in less than an hour. Furthermore, when used with clinical samples, the assay had a coincidence rate of 98.26% with the culture-biochemical method and a kappa index value of 0.9433. These data indicate that the RPA-LFS assay represents a major improvement for P. aeruginosa detection, especially in resource-limited areas.
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Affiliation(s)
- Haitao Yang
- Jiangsu Key Laboratory of Marine Biological Resources and Environment, Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening, Co-Innovation Center of Jiangsu Marine Bio-industry Technology, School of Pharmacy, Jiangsu Ocean University, Lianyungangg, China
| | - Yan Wang
- Department of Laboratory Medicine, The Second People's Hospital of Lianyungangg City, Lianyungangg, China
| | - Qiankun Yang
- Jiangsu Key Laboratory of Marine Biological Resources and Environment, Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening, Co-Innovation Center of Jiangsu Marine Bio-industry Technology, School of Pharmacy, Jiangsu Ocean University, Lianyungangg, China
| | - Hui Fan
- Jiangsu Key Laboratory of Marine Biological Resources and Environment, Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening, Co-Innovation Center of Jiangsu Marine Bio-industry Technology, School of Pharmacy, Jiangsu Ocean University, Lianyungangg, China
| | - Lei Wang
- Jiangsu Key Laboratory of Marine Biological Resources and Environment, Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening, Co-Innovation Center of Jiangsu Marine Bio-industry Technology, School of Pharmacy, Jiangsu Ocean University, Lianyungangg, China.,Department of Laboratory Medicine, The Second People's Hospital of Lianyungangg City, Lianyungangg, China
| | - Tianmeng Zhang
- Jiangsu Key Laboratory of Marine Biological Resources and Environment, Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening, Co-Innovation Center of Jiangsu Marine Bio-industry Technology, School of Pharmacy, Jiangsu Ocean University, Lianyungangg, China
| | - Zhixing Li
- Jiangsu Key Laboratory of Marine Biological Resources and Environment, Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening, Co-Innovation Center of Jiangsu Marine Bio-industry Technology, School of Pharmacy, Jiangsu Ocean University, Lianyungangg, China
| | - Gang Liu
- Jiangsu Key Laboratory of Marine Biological Resources and Environment, Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening, Co-Innovation Center of Jiangsu Marine Bio-industry Technology, School of Pharmacy, Jiangsu Ocean University, Lianyungangg, China
| | - Panpan Zhao
- Jiangsu Key Laboratory of Marine Biological Resources and Environment, Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening, Co-Innovation Center of Jiangsu Marine Bio-industry Technology, School of Pharmacy, Jiangsu Ocean University, Lianyungangg, China.,Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Huahua Wu
- Jiangsu Key Laboratory of Marine Biological Resources and Environment, Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening, Co-Innovation Center of Jiangsu Marine Bio-industry Technology, School of Pharmacy, Jiangsu Ocean University, Lianyungangg, China
| | - Jingquan Dong
- Jiangsu Key Laboratory of Marine Biological Resources and Environment, Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening, Co-Innovation Center of Jiangsu Marine Bio-industry Technology, School of Pharmacy, Jiangsu Ocean University, Lianyungangg, China
| | - Wei Liang
- Laboratory Department of Ningbo First Hospital, Ningbo Hospital of Zhejiang University, Ningbo, China
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27
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Mohamed MF, Wood SJ, Roy R, Reiser J, Kuzel TM, Shafikhani SH. Pseudomonas aeruginosa ExoT induces G1 cell cycle arrest in melanoma cells. Cell Microbiol 2021; 23:e13339. [PMID: 33821556 PMCID: PMC8277761 DOI: 10.1111/cmi.13339] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 03/31/2021] [Accepted: 04/01/2021] [Indexed: 12/19/2022]
Abstract
Recently, we demonstrated that Pseudomonas aeruginosa Exotoxin T (ExoT) employs two distinct mechanisms to induce potent apoptotic cytotoxicity in a variety of cancer cell lines. We further demonstrated that it can significantly reduce tumour growth in an animal model for melanoma. During these studies, we observed that melanoma cells that were transfected with ExoT failed to undergo mitosis, regardless of whether they eventually succumbed to ExoT-induced apoptosis or survived in ExoT's presence. In this report, we sought to investigate ExoT's antiproliferative activity in melanoma. We delivered ExoT into B16 melanoma cells by bacteria (to show necessity) and by transfection (to show sufficiency). Our data indicate that ExoT exerts a potent antiproliferative function in melanoma cells. We show that ExoT causes cell cycle arrest in G1 interphase in melanoma cells by dampening the G1/S checkpoint proteins. Our data demonstrate that both domains of ExoT; (the ADP-ribosyltransferase (ADPRT) domain and the GTPase activating protein (GAP) domain); contribute to ExoT-induced G1 cell cycle arrest in melanoma. Finally, we show that the ADPRT-induced G1 cell cycle arrest in melanoma cells likely involves the Crk adaptor protein. Our data reveal a novel virulence function for ExoT and further highlight the therapeutic potential of ExoT against cancer.
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Affiliation(s)
- Mohamed F. Mohamed
- Department of Medicine/ Division of Hematology/Oncology/Cell Therapy, Rush University Medical Center, Chicago, IL, USA
- Department of Bacteriology, Mycology and Immunology, Faculty of Veterinary Medicine, Beni-Suef University, Egypt
| | - Stephen J. Wood
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, IL, USA
| | - Ruchi Roy
- Department of Medicine/ Division of Hematology/Oncology/Cell Therapy, Rush University Medical Center, Chicago, IL, USA
| | - Jochen Reiser
- Department of Medicine/ Division of Hematology/Oncology/Cell Therapy, Rush University Medical Center, Chicago, IL, USA
| | - Timothy M. Kuzel
- Department of Medicine/ Division of Hematology/Oncology/Cell Therapy, Rush University Medical Center, Chicago, IL, USA
| | - Sasha H. Shafikhani
- Department of Medicine/ Division of Hematology/Oncology/Cell Therapy, Rush University Medical Center, Chicago, IL, USA
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, IL, USA
- Cancer Center, Rush University Medical Center, Chicago, IL, USA
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28
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Tayyrov A, Wei C, Fetz C, Goryachkin A, Schächle P, Nyström L, Künzler M. Cytoplasmic Lipases-A Novel Class of Fungal Defense Proteins Against Nematodes. FRONTIERS IN FUNGAL BIOLOGY 2021; 2:696972. [PMID: 37744157 PMCID: PMC10512399 DOI: 10.3389/ffunb.2021.696972] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Accepted: 05/31/2021] [Indexed: 09/26/2023]
Abstract
Fungi are an attractive food source for predators such as fungivorous nematodes. Several fungal defense proteins and their protective mechanisms against nematodes have been described. Many of these proteins are lectins which are stored in the cytoplasm of the fungal cells and bind to specific glycan epitopes in the digestive tract of the nematode upon ingestion. Here, we studied two novel nematotoxic proteins with lipase domains from the model mushroom Coprinopsis cinerea. These cytoplasmically localized proteins were found to be induced in the vegetative mycelium of C. cinerea upon challenge with fungivorous nematode Aphelenchus avenae. The proteins showed nematotoxicity when heterologously expressed in E. coli and fed to several bacterivorous nematodes. Site-specific mutagenesis of predicted catalytic residues eliminated the in-vitro lipase activity of the proteins and significantly reduced their nematotoxicity, indicating the importance of the lipase activity for the nematotoxicity of these proteins. Our results suggest that cytoplasmic lipases constitute a novel class of fungal defense proteins against predatory nematodes. These findings improve our understanding of fungal defense mechanisms against predators and may find applications in the control of parasitic nematodes in agriculture and medicine.
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Affiliation(s)
- Annageldi Tayyrov
- Department of Biology, Institute of Microbiology, ETH Zürich, Zurich, Switzerland
| | - Chunyue Wei
- Department of Health Sciences and Technology, Institute of Food, Nutrition and Health, ETH Zürich, Zurich, Switzerland
| | - Céline Fetz
- Department of Biology, Institute of Microbiology, ETH Zürich, Zurich, Switzerland
| | - Aleksandr Goryachkin
- Department of Biology, Institute of Microbiology, ETH Zürich, Zurich, Switzerland
| | - Philipp Schächle
- Department of Biology, Institute of Microbiology, ETH Zürich, Zurich, Switzerland
| | - Laura Nyström
- Department of Health Sciences and Technology, Institute of Food, Nutrition and Health, ETH Zürich, Zurich, Switzerland
| | - Markus Künzler
- Department of Biology, Institute of Microbiology, ETH Zürich, Zurich, Switzerland
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29
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The bacterial toxin ExoU requires a host trafficking chaperone for transportation and to induce necrosis. Nat Commun 2021; 12:4024. [PMID: 34188051 PMCID: PMC8241856 DOI: 10.1038/s41467-021-24337-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 06/11/2021] [Indexed: 12/17/2022] Open
Abstract
Pseudomonas aeruginosa can cause nosocomial infections, especially in ventilated or cystic fibrosis patients. Highly pathogenic isolates express the phospholipase ExoU, an effector of the type III secretion system that acts on plasma membrane lipids, causing membrane rupture and host cell necrosis. Here, we use a genome-wide screen to discover that ExoU requires DNAJC5, a host chaperone, for its necrotic activity. DNAJC5 is known to participate in an unconventional secretory pathway for misfolded proteins involving anterograde vesicular trafficking. We show that DNAJC5-deficient human cells, or Drosophila flies knocked-down for the DNAJC5 orthologue, are largely resistant to ExoU-dependent virulence. ExoU colocalizes with DNAJC5-positive vesicles in the host cytoplasm. DNAJC5 mutations preventing vesicle trafficking (previously identified in adult neuronal ceroid lipofuscinosis, a human congenital disease) inhibit ExoU-dependent cell lysis. Our results suggest that, once injected into the host cytoplasm, ExoU docks to DNAJC5-positive secretory vesicles to reach the plasma membrane, where it can exert its phospholipase activity Phospholipase ExoU from Pseudomonas aeruginosa acts on plasma membrane lipids in infected cells, causing membrane rupture and host cell necrosis. Here, Deruelle et al. show that once injected into the host cytoplasm, ExoU requires a host chaperone found on secretory vesicles to reach the plasma membrane and exerts its phospholipase activity.
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Morin CD, Déziel E, Gauthier J, Levesque RC, Lau GW. An Organ System-Based Synopsis of Pseudomonas aeruginosa Virulence. Virulence 2021; 12:1469-1507. [PMID: 34180343 PMCID: PMC8237970 DOI: 10.1080/21505594.2021.1926408] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Driven in part by its metabolic versatility, high intrinsic antibiotic resistance, and a large repertoire of virulence factors, Pseudomonas aeruginosa is expertly adapted to thrive in a wide variety of environments, and in the process, making it a notorious opportunistic pathogen. Apart from the extensively studied chronic infection in the lungs of people with cystic fibrosis (CF), P. aeruginosa also causes multiple serious infections encompassing essentially all organs of the human body, among others, lung infection in patients with chronic obstructive pulmonary disease, primary ciliary dyskinesia and ventilator-associated pneumonia; bacteremia and sepsis; soft tissue infection in burns, open wounds and postsurgery patients; urinary tract infection; diabetic foot ulcers; chronic suppurative otitis media and otitis externa; and keratitis associated with extended contact lens use. Although well characterized in the context of CF, pathogenic processes mediated by various P. aeruginosa virulence factors in other organ systems remain poorly understood. In this review, we use an organ system-based approach to provide a synopsis of disease mechanisms exerted by P. aeruginosa virulence determinants that contribute to its success as a versatile pathogen.
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Affiliation(s)
- Charles D Morin
- Centre Armand-Frappier Santé Biotechnologie, Institut National De La Recherche Scientifique (INRS), Laval, Quebec, Canada
| | - Eric Déziel
- Centre Armand-Frappier Santé Biotechnologie, Institut National De La Recherche Scientifique (INRS), Laval, Quebec, Canada
| | - Jeff Gauthier
- Département De Microbiologie-infectiologie Et Immunologie, Institut De Biologie Intégrative Et Des Systèmes (IBIS), Université Laval, Québec City, Quebec, Canada
| | - Roger C Levesque
- Département De Microbiologie-infectiologie Et Immunologie, Institut De Biologie Intégrative Et Des Systèmes (IBIS), Université Laval, Québec City, Quebec, Canada
| | - Gee W Lau
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, IL, US
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A pipeline to evaluate inhibitors of the Pseudomonas aeruginosa exotoxin U. Biochem J 2021; 478:647-668. [PMID: 33459338 PMCID: PMC7886320 DOI: 10.1042/bcj20200780] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 01/15/2021] [Accepted: 01/18/2021] [Indexed: 01/07/2023]
Abstract
Pseudomonas aeruginosa has recently been highlighted by the World Health Organisation (WHO) as a major threat with high priority for the development of new therapies. In severe P. aeruginosa infections, the phospholipase activity of the type 3 secretion system toxin, ExoU, induces lysis of target host cells and results in the poorest clinical outcomes. We have developed an integrated pipeline to evaluate small molecule inhibitors of ExoU in vitro and in cultured cell models, including a disease-relevant corneal epithelial (HCE-T) scratch and infection model using florescence microscopy and cell viability assays. Compounds Pseudolipasin A, compound A and compound B were effective in vitro inhibitors of ExoU and mitigated P. aeruginosa ExoU-dependent cytotoxicity after infection of HCE-T cells at concentrations as low as 0.5 µM. Addition of the antimicrobial moxifloxacin controlled bacterial load, allowing these assays to be extended from 6 h to 24 h. P. aeruginosa remained cytotoxic to HCE-T cells with moxifloxacin, present at the minimal inhibitory concentration for 24 h, but, when used in combination with either Pseudolipasin A, compound A or compound B, a greater amount of viable cells and scratch healing were observed. Thus, our pipeline provides evidence that ExoU inhibitors could be used in combination with certain antimicrobials as a novel means to treat infections due to ExoU producing P. aeruginosa, as well as the means to identify more potent ExoU inhibitors for future therapeutics.
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32
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Pseudomonas aeruginosa Ventilator-Associated Pneumonia Rabbit Model for Preclinical Drug Development. Antimicrob Agents Chemother 2021; 65:e0272420. [PMID: 33972247 DOI: 10.1128/aac.02724-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Development and validation of large animal models of Pseudomonas aeruginosa ventilator-associated pneumonia are needed for testing new drug candidates in a manner that mimics how they will be used clinically. We developed a new model in which rabbits were ventilated with low tidal volume and challenged with P. aeruginosa to recapitulate hallmark clinical features of acute respiratory distress syndrome (ARDS): acute lung injury and inflammation, progressive decrease in arterial oxygen partial pressure to fractional inspired oxygen PaO2:FiO2, leukopenia, neutropenia, thrombocytopenia, hyperlactatemia, severe hypotension, bacterial dissemination from lung to other organs, multiorgan dysfunction, and ultimately death. We evaluated the predictive power of this rabbit model for antibiotic efficacy testing by determining whether a humanized dosing regimen of meropenem, a potent antipseudomonal β-lactam antibiotic, when administered with or without intensive care unit (ICU)-supportive care (fluid challenge and norepinephrine), could halt or reverse natural disease progression. Our humanized meropenem dosing regimen produced a plasma concentration-time profile in the rabbit model similar to those reported in patients with ventilator-associated bacterial pneumonia. In this rabbit model, treatment with humanized meropenem and ICU-supportive care achieved the highest level of survival, halted the worsening of ARDS biomarkers, and reversed lethal hypotension, although treatment with humanized meropenem alone also conferred some protection compared to treatment with placebo (saline) alone or placebo plus ICU-supportive care. In conclusion, this rabbit model could help predict whether an antibiotic will be efficacious for the treatment of human ventilator-associated pneumonia.
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Swietnicki W. Secretory System Components as Potential Prophylactic Targets for Bacterial Pathogens. Biomolecules 2021; 11:892. [PMID: 34203937 PMCID: PMC8232601 DOI: 10.3390/biom11060892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 06/13/2021] [Accepted: 06/14/2021] [Indexed: 01/18/2023] Open
Abstract
Bacterial secretory systems are essential for virulence in human pathogens. The systems have become a target of alternative antibacterial strategies based on small molecules and antibodies. Strategies to use components of the systems to design prophylactics have been less publicized despite vaccines being the preferred solution to dealing with bacterial infections. In the current review, strategies to design vaccines against selected pathogens are presented and connected to the biology of the system. The examples are given for Y. pestis, S. enterica, B. anthracis, S. flexneri, and other human pathogens, and discussed in terms of effectiveness and long-term protection.
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Affiliation(s)
- Wieslaw Swietnicki
- Department of Immunology of Infectious Diseases, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, ul. R. Weigla 12, 53-114 Wroclaw, Poland
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NAD(H)-mediated tetramerization controls the activity of Legionella pneumophila phospholipase PlaB. Proc Natl Acad Sci U S A 2021; 118:2017046118. [PMID: 34074754 DOI: 10.1073/pnas.2017046118] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The virulence factor PlaB promotes lung colonization, tissue destruction, and intracellular replication of Legionella pneumophila, the causative agent of Legionnaires' disease. It is a highly active phospholipase exposed at the bacterial surface and shows an extraordinary activation mechanism by tetramer deoligomerization. To unravel the molecular basis for enzyme activation and localization, we determined the crystal structure of PlaB in its tetrameric form. We found that the tetramer is a dimer of identical dimers, and a monomer consists of an N-terminal α/β-hydrolase domain expanded by two noncanonical two-stranded β-sheets, β-6/β-7 and β-9/β-10. The C-terminal domain reveals a fold displaying a bilobed β-sandwich with a hook structure required for dimer formation and structural complementation of the enzymatic domain in the neighboring monomer. This highlights the dimer as the active form. Δβ-9/β-10 mutants showed a decrease in the tetrameric fraction and altered activity profiles. The variant also revealed restricted binding to membranes resulting in mislocalization and bacterial lysis. Unexpectedly, we observed eight NAD(H) molecules at the dimer/dimer interface, suggesting that these molecules stabilize the tetramer and hence lead to enzyme inactivation. Indeed, addition of NAD(H) increased the fraction of the tetramer and concomitantly reduced activity. Together, these data reveal structural elements and an unprecedented NAD(H)-mediated tetramerization mechanism required for spatial and enzymatic control of a phospholipase virulence factor. The allosteric regulatory process identified here is suited to fine tune PlaB in a way that protects Legionella pneumophila from self-inflicted lysis while ensuring its activity at the pathogen-host interface.
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Hajra D, Nair AV, Chakravortty D. An elegant nano-injection machinery for sabotaging the host: Role of Type III secretion system in virulence of different human and animal pathogenic bacteria. Phys Life Rev 2021; 38:25-54. [PMID: 34090822 DOI: 10.1016/j.plrev.2021.05.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Accepted: 05/23/2021] [Indexed: 01/22/2023]
Abstract
Various Gram-negative bacteria possess a specialized membrane-bound protein secretion system known as the Type III secretion system (T3SS), which transports the bacterial effector proteins into the host cytosol thereby helping in bacterial pathogenesis. The T3SS has a special needle-like translocon that can sense the contact with the host cell membrane and translocate effectors. The export apparatus of T3SS recognizes these effector proteins bound to chaperones and translocates them into the host cell. Once in the host cell cytoplasm, these effector proteins result in modulation of the host system and promote bacterial localization and infection. Using molecular biology, bioinformatics, genetic techniques, electron microscopic studies, and mathematical modeling, the structure and function of the T3SS and the corresponding effector proteins in various bacteria have been studied. The strategies used by different human pathogenic bacteria to modulate the host system and thereby enhance their virulence mechanism using T3SS have also been well studied. Here we review the history, evolution, and general structure of the T3SS, highlighting the details of its comparison with the flagellar export machinery. Also, this article provides mechanistic details about the common role of T3SS in subversion and manipulation of host cellular processes. Additionally, this review describes specific T3SS apparatus and the role of their specific effectors in bacterial pathogenesis by considering several human and animal pathogenic bacteria.
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Affiliation(s)
- Dipasree Hajra
- Department of Microbiology & Cell Biology, Indian Institute of Science, India
| | - Abhilash Vijay Nair
- Department of Microbiology & Cell Biology, Indian Institute of Science, India
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Yoon EJ, Jeong SH. Mobile Carbapenemase Genes in Pseudomonas aeruginosa. Front Microbiol 2021; 12:614058. [PMID: 33679638 PMCID: PMC7930500 DOI: 10.3389/fmicb.2021.614058] [Citation(s) in RCA: 82] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 01/04/2021] [Indexed: 02/06/2023] Open
Abstract
Carbapenem-resistant Pseudomonas aeruginosa is one of the major concerns in clinical settings impelling a great challenge to antimicrobial therapy for patients with infections caused by the pathogen. While membrane permeability, together with derepression of the intrinsic beta-lactamase gene, is the global prevailing mechanism of carbapenem resistance in P. aeruginosa, the acquired genes for carbapenemases need special attention because horizontal gene transfer through mobile genetic elements, such as integrons, transposons, plasmids, and integrative and conjugative elements, could accelerate the dissemination of the carbapenem-resistant P. aeruginosa. This review aimed to illustrate epidemiologically the carbapenem resistance in P. aeruginosa, including the resistance rates worldwide and the carbapenemase-encoding genes along with the mobile genetic elements responsible for the horizontal dissemination of the drug resistance determinants. Moreover, the modular mobile elements including the carbapenemase-encoding gene, also known as the P. aeruginosa resistance islands, are scrutinized mostly for their structures.
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Affiliation(s)
- Eun-Jeong Yoon
- Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul, South Korea
| | - Seok Hoon Jeong
- Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul, South Korea
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37
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Horna G, Ruiz J. Type 3 secretion system of Pseudomonas aeruginosa. Microbiol Res 2021; 246:126719. [PMID: 33582609 DOI: 10.1016/j.micres.2021.126719] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 01/19/2021] [Accepted: 01/26/2021] [Indexed: 12/27/2022]
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen, mainly affecting severe patients, such as those in intensive care units (ICUs). High levels of antibiotic resistance and a long battery of virulence factors characterise this pathogen. Among virulence factors, the T3SS (Type 3 Secretion Systems) are especially relevant, being one of the most important virulence factors in P. aeruginosa. T3SS are a complex "molecular syringe" able to inject different effectors in host cells, subverting cell machinery influencing immune responses, and increasing bacterial survival rates. While T3SS have been largely studied and the molecular structure and main effector functions have been established, a series of questions and further points remain to be clarified or established. The key role of T3SS in P. aeruginosa virulence has resulted in the search for T3SS-targeting molecules able to impair their functions and subsequently improve patient outcomes. This review aims to summarise the most relevant features of the P. aeruginosa T3SS.
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Affiliation(s)
- Gertrudis Horna
- Universidad Catolica Los Angeles de Chimbote, Instituto de Investigación, Chimbote, Peru.
| | - Joaquim Ruiz
- Laboratorio de Microbiología Molecular y Genómica Bacteriana, Universidad Científica del Sur, Panamericana Sur, Km 19, Lima, Peru.
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38
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Juárez-Rodríguez MM, Cortes-López H, García-Contreras R, González-Pedrajo B, Díaz-Guerrero M, Martínez-Vázquez M, Rivera-Chávez JA, Soto-Hernández RM, Castillo-Juárez I. Tetradecanoic Acids With Anti-Virulence Properties Increase the Pathogenicity of Pseudomonas aeruginosa in a Murine Cutaneous Infection Model. Front Cell Infect Microbiol 2021; 10:597517. [PMID: 33585272 PMCID: PMC7876447 DOI: 10.3389/fcimb.2020.597517] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 12/08/2020] [Indexed: 12/25/2022] Open
Abstract
Blocking virulence is a promising alternative to counteract Pseudomonas aeruginosa infections. In this regard, the phenomenon of cell-cell communication by quorum sensing (QS) is an important anti-virulence target. In this field, fatty acids (FA) have gained notoriety for their role as autoinducers, as well as anti-virulence molecules in vitro, like some saturated FA (SAFA). In this study, we analyzed the anti-virulence activity of SAFA with 12 to18 carbon atoms and compared their effect with the putative autoinducer cis-2-decenoic acid (CDA). The effect of SAFA on six QS-regulated virulence factors and on the secretion of the exoenzyme ExoU was evaluated. In addition, a murine cutaneous infection model was used to determine their influence on the establishment and damage caused by P. aeruginosa PA14. Dodecanoic (lauric, C12:0) and tetradecanoic (myristic, C14:0) acids (SAFA C12-14) reduced the production of pyocyanin by 35-58% at 40 and 1,000 µM, while CDA inhibited it 62% at a 3.1 µM concentration. Moreover, the SAFA C12-14 reduced swarming by 90% without affecting biofilm formation. In contrast, CDA reduced the biofilm by 57% at 3 µM but did not affect swarming. Furthermore, lauric and myristic acids abolished ExoU secretion at 100 and 50 µM respectively, while CDA reduced it by ≈ 92% at 100 µM. Remarkably, the coadministration of myristic acid (200 and 1,000 µM) with P. aeruginosa PA14 induced greater damage and reduced survival of the animals up to 50%, whereas CDA to 500 µM reduced the damage without affecting the viability of the PA14 strain. Hence, our results show that SAFA C12-14 and CDA have a role in regulation of P. aeruginosa virulence, although their inhibition/activation molecular mechanisms are different in complex environments such as in vivo systems.
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Affiliation(s)
| | - Humberto Cortes-López
- Laboratorio de Fitoquímica, Posgrado de Botánica, Colegio de Postgraduados, Texcoco, Mexico
| | - Rodolfo García-Contreras
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Bertha González-Pedrajo
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Miguel Díaz-Guerrero
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Mariano Martínez-Vázquez
- Departamento de Productos Naturales, Instituto de Química, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - José Alberto Rivera-Chávez
- Departamento de Productos Naturales, Instituto de Química, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | | | - Israel Castillo-Juárez
- Laboratorio de Fitoquímica, Posgrado de Botánica, Colegio de Postgraduados, Texcoco, Mexico
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Tessmer MH, DeCero SA, Del Alamo D, Riegert MO, Meiler J, Frank DW, Feix JB. Characterization of the ExoU activation mechanism using EPR and integrative modeling. Sci Rep 2020; 10:19700. [PMID: 33184362 PMCID: PMC7665212 DOI: 10.1038/s41598-020-76023-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 10/19/2020] [Indexed: 12/17/2022] Open
Abstract
ExoU, a type III secreted phospholipase effector of Pseudomonas aeruginosa, serves as a prototype to model large, dynamic, membrane-associated proteins. ExoU is synergistically activated by interactions with membrane lipids and ubiquitin. To dissect the activation mechanism, structural homology was used to identify an unstructured loop of approximately 20 residues in the ExoU amino acid sequence. Mutational analyses indicate the importance of specific loop amino acid residues in mediating catalytic activity. Engineered disulfide cross-links show that loop movement is required for activation. Site directed spin labeling EPR and DEER (double electron-electron resonance) studies of apo and holo states demonstrate local conformational changes at specific sites within the loop and a conformational shift of the loop during activation. These data are consistent with the formation of a substrate-binding pocket providing access to the catalytic site. DEER distance distributions were used as constraints in RosettaDEER to construct ensemble models of the loop in both apo and holo states, significantly extending the range for modeling a conformationally dynamic loop.
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Affiliation(s)
- Maxx H Tessmer
- Department of Chemistry, University of Washington, Seattle, WA, USA
| | - Samuel A DeCero
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Diego Del Alamo
- Department of Chemistry and Center for Structural Biology, Vanderbilt University, Nashville, TN, USA
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Molly O Riegert
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Jens Meiler
- Department of Chemistry and Center for Structural Biology, Vanderbilt University, Nashville, TN, USA
- Institute for Drug Discovery, Leipzig University Medical School, Leipzig SAC, Germany
| | - Dara W Frank
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, WI, USA.
| | - Jimmy B Feix
- Department of Biophysics, Medical College of Wisconsin, Milwaukee, WI, USA
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Armentrout EI, Kundracik EC, Rietsch A. Cell-type-specific hypertranslocation of effectors by the Pseudomonas aeruginosa type III secretion system. Mol Microbiol 2020; 115:305-319. [PMID: 33012037 DOI: 10.1111/mmi.14617] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 09/22/2020] [Indexed: 12/23/2022]
Abstract
Many Gram-negative pathogens use a type III secretion system (T3SS) to promote disease by injecting effector proteins into host cells. Common to many T3SSs is that injection of effector proteins is feedback inhibited. The mechanism of feedback inhibition and its role in pathogenesis are unclear. In the case of P. aeruginosa, the effector protein ExoS is central to limiting effector injection. ExoS is bifunctional, with an amino-terminal RhoGAP and a carboxy-terminal ADP-ribosyltransferase domain. We demonstrate that both domains are required to fully feedback inhibit effector injection. The RhoGAP-, but not the ADP-ribosyltransferase domain of the related effector protein ExoT also participates. Feedback inhibition does not involve translocator insertion nor pore-formation. Instead, feedback inhibition is due, in part, to a loss of the activating trigger for effector injection, and likely also decreased translocon stability. Surprisingly, feedback inhibition is abrogated in phagocytic cells. The lack of feedback inhibition in these cells requires phagocytic uptake of the bacteria, but cannot be explained through acidification of the phagosome or calcium limitation. Given that phagocytes are crucial for controlling P. aeruginosa infections, our data suggest that feedback inhibition allows P. aeruginosa to direct its effector arsenal against the cell types most damaging to its survival.
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Affiliation(s)
- Erin I Armentrout
- Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, OH, USA
| | - Emma C Kundracik
- Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, OH, USA
| | - Arne Rietsch
- Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, OH, USA
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41
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Barajas HR, Martínez-Sánchez S, Romero MF, Álvarez CH, Servín-González L, Peimbert M, Cruz-Ortega R, García-Oliva F, Alcaraz LD. Testing the Two-Step Model of Plant Root Microbiome Acquisition Under Multiple Plant Species and Soil Sources. Front Microbiol 2020; 11:542742. [PMID: 33162946 PMCID: PMC7581803 DOI: 10.3389/fmicb.2020.542742] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 09/11/2020] [Indexed: 12/23/2022] Open
Abstract
The two-step model for plant root microbiomes considers soil as the primary microbial source. Active selection of the plant’s bacterial inhabitants results in a biodiversity decrease toward roots. We collected sixteen samples of in situ ruderal plant roots and their soils and used these soils as the main microbial input for single genotype tomatoes grown in a greenhouse. Our main goal was to test the soil influence in the structuring of rhizosphere microbiomes, minimizing environmental variability, while testing multiple plant species. We massively sequenced the 16S rRNA and shotgun metagenomes of the soils, in situ plants, and tomato roots. We identified a total of 271,940 bacterial operational taxonomic units (OTUs) within the soils, rhizosphere and endospheric microbiomes. We annotated by homology a total of 411,432 (13.07%) of the metagenome predicted proteins. Tomato roots did follow the two-step model with lower α-diversity than soil, while ruderal plants did not. Surprisingly, ruderal plants are probably working as a microenvironmental oasis providing moisture and plant-derived nutrients, supporting larger α-diversity. Ruderal plants and their soils are closer according to their microbiome community composition than tomato and its soil, based on OTUs and protein comparisons. We expected that tomato β-diversity clustered together with their soil, if it is the main rhizosphere microbiome structuring factor. However, tomato microbiome β-diversity was associated with plant genotype in most samples (81.2%), also supported by a larger set of enriched proteins in tomato rhizosphere than soil or ruderals. The most abundant bacteria found in soils was the Actinobacteria Solirubrobacter soli, ruderals were dominated by the Proteobacteria Sphingomonas sp. URGHD0057, and tomato mainly by the Bacteroidetes Ohtaekwangia koreensis, Flavobacterium terrae, Niastella vici, and Chryseolinea serpens. We calculated a metagenomic tomato root core of 51 bacterial genera and 2,762 proteins, which could be the basis for microbiome-oriented plant breeding programs. We attributed a larger diversity in ruderal plants roots exudates as an effect of the moisture and nutrient acting as a microbial harbor. The tomato and ruderal metagenomic differences are probably due to plant domestication trade-offs, impacting plant-bacteria interactions.
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Affiliation(s)
- Hugo R Barajas
- Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Shamayim Martínez-Sánchez
- Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Miguel F Romero
- Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Cristóbal Hernández Álvarez
- Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Luis Servín-González
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Mariana Peimbert
- Departamento de Ciencias Naturales, Unidad Cuajimalpa, Universidad Autónoma Metropolitana, Mexico City, Mexico
| | - Rocío Cruz-Ortega
- Laboratorio de Alelopatía, Departamento de Ecología Funcional, Instituto de Ecología, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Felipe García-Oliva
- Instituto de Investigaciones en Ecosistemas y Sustentabilidad, Universidad Nacional Autónoma de México, Morelia, Mexico
| | - Luis D Alcaraz
- Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
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42
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Khan M, Stapleton F, Summers S, Rice SA, Willcox MDP. Antibiotic Resistance Characteristics of Pseudomonas aeruginosa Isolated from Keratitis in Australia and India. Antibiotics (Basel) 2020; 9:antibiotics9090600. [PMID: 32937932 PMCID: PMC7559795 DOI: 10.3390/antibiotics9090600] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 09/08/2020] [Accepted: 09/09/2020] [Indexed: 02/07/2023] Open
Abstract
This study investigated genomic differences in Australian and Indian Pseudomonas aeruginosa isolates from keratitis (infection of the cornea). Overall, the Indian isolates were resistant to more antibiotics, with some of those isolates being multi-drug resistant. Acquired genes were related to resistance to fluoroquinolones, aminoglycosides, beta-lactams, macrolides, sulphonamides, and tetracycline and were more frequent in Indian (96%) than in Australian (35%) isolates (p = 0.02). Indian isolates had large numbers of gene variations (median 50,006, IQR = 26,967-50,600) compared to Australian isolates (median 26,317, IQR = 25,681-33,780). There were a larger number of mutations in the mutL and uvrD genes associated with the mismatch repair (MMR) system in Indian isolates, which may result in strains losing their efficacy for DNA repair. The number of gene variations were greater in isolates carrying MMR system genes or exoU. In the phylogenetic division, the number of core genes were similar in both groups, but Indian isolates had larger numbers of pan genes (median 6518, IQR = 6040-6935). Clones related to three different sequence types-ST308, ST316, and ST491-were found among Indian isolates. Only one clone, ST233, containing two strains was present in Australian isolates. The most striking differences between Australian and Indian isolates were carriage of exoU (that encodes a cytolytic phospholipase) in Indian isolates and exoS (that encodes for GTPase activator activity) in Australian isolates, large number of acquired resistance genes, greater changes to MMR genes, and a larger pan genome as well as increased overall genetic variation in the Indian isolates.
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Affiliation(s)
- Mahjabeen Khan
- School of Optometry and Vision Science, UNSW, Sydney, NSW 2052, Australia; (M.K.); (F.S.)
| | - Fiona Stapleton
- School of Optometry and Vision Science, UNSW, Sydney, NSW 2052, Australia; (M.K.); (F.S.)
| | - Stephen Summers
- The Singapore Centre for Environment Life Sciences Engineering (SCELSE), The School of Biological Sciences, Nanyang Technological University, Singapore 639798, Singapore; (S.S.); (S.A.R.)
| | - Scott A. Rice
- The Singapore Centre for Environment Life Sciences Engineering (SCELSE), The School of Biological Sciences, Nanyang Technological University, Singapore 639798, Singapore; (S.S.); (S.A.R.)
- The ithree Institute, The University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Mark D. P. Willcox
- School of Optometry and Vision Science, UNSW, Sydney, NSW 2052, Australia; (M.K.); (F.S.)
- Correspondence: ; Tel.: +61-2-9385-4164
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Spatiotemporal Regulation of Vibrio Exotoxins by HlyU and Other Transcriptional Regulators. Toxins (Basel) 2020; 12:toxins12090544. [PMID: 32842612 PMCID: PMC7551375 DOI: 10.3390/toxins12090544] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 08/17/2020] [Accepted: 08/19/2020] [Indexed: 02/06/2023] Open
Abstract
After invading a host, bacterial pathogens secrete diverse protein toxins to disrupt host defense systems. To ensure successful infection, however, pathogens must precisely regulate the expression of those exotoxins because uncontrolled toxin production squanders energy. Furthermore, inappropriate toxin secretion can trigger host immune responses that are detrimental to the invading pathogens. Therefore, bacterial pathogens use diverse transcriptional regulators to accurately regulate multiple exotoxin genes based on spatiotemporal conditions. This review covers three major exotoxins in pathogenic Vibrio species and their transcriptional regulation systems. When Vibrio encounters a host, genes encoding cytolysin/hemolysin, multifunctional-autoprocessing repeats-in-toxin (MARTX) toxin, and secreted phospholipases are coordinately regulated by the transcriptional regulator HlyU. At the same time, however, they are distinctly controlled by a variety of other transcriptional regulators. How this coordinated but distinct regulation of exotoxins makes Vibrio species successful pathogens? In addition, anti-virulence strategies that target the coordinating master regulator HlyU and related future research directions are discussed.
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Niu M, Keller NP. Co-opting oxylipin signals in microbial disease. Cell Microbiol 2020; 21:e13025. [PMID: 30866138 DOI: 10.1111/cmi.13025] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 02/01/2019] [Accepted: 02/06/2019] [Indexed: 12/14/2022]
Abstract
Oxylipins, or oxygenated lipids, are universal signalling molecules across all kingdoms of life. These molecules, either produced by microbial pathogens or their mammalian host, regulate inflammation during microbial infection. In this review, we summarise current literature on the biosynthesis pathways of microbial oxylipins and their biological activity towards mammalian cells. Collectively, these studies have illustrated how microbial pathogens can modulate immune rsponse and disease outcome via oxylipin-mediated mechanisms.
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Affiliation(s)
- Mengyao Niu
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Nancy P Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin.,Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin
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Achromobacter xylosoxidans Cellular Pathology Is Correlated with Activation of a Type III Secretion System. Infect Immun 2020; 88:IAI.00136-20. [PMID: 32366575 DOI: 10.1128/iai.00136-20] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 04/28/2020] [Indexed: 02/07/2023] Open
Abstract
Achromobacter xylosoxidans is increasingly recognized as a colonizer of cystic fibrosis (CF) patients, but the role that A. xylosoxidans plays in pathology remains unknown. This knowledge gap is largely due to the lack of model systems available to study the toxic potential of this bacterium. Recently, a phospholipase A2 (PLA2) encoded by a majority of A. xylosoxidans genomes, termed AxoU, was identified. Here, we show that AxoU is a type III secretion system (T3SS) substrate that induces cytotoxicity to mammalian cells. A tissue culture model was developed showing that a subset of A. xylosoxidans isolates from CF patients induce cytotoxicity in macrophages, suggestive of a pathogenic or inflammatory role in the CF lung. In a toxic strain, cytotoxicity is correlated with transcriptional activation of axoU and T3SS genes, demonstrating that this model can be used as a tool to identify and track expression of virulence determinants produced by this poorly understood bacterium.
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Lucas R, Hadizamani Y, Gonzales J, Gorshkov B, Bodmer T, Berthiaume Y, Moehrlen U, Lode H, Huwer H, Hudel M, Mraheil MA, Toque HAF, Chakraborty T, Hamacher J. Impact of Bacterial Toxins in the Lungs. Toxins (Basel) 2020; 12:toxins12040223. [PMID: 32252376 PMCID: PMC7232160 DOI: 10.3390/toxins12040223] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 03/30/2020] [Accepted: 03/31/2020] [Indexed: 12/13/2022] Open
Abstract
Bacterial toxins play a key role in the pathogenesis of lung disease. Based on their structural and functional properties, they employ various strategies to modulate lung barrier function and to impair host defense in order to promote infection. Although in general, these toxins target common cellular signaling pathways and host compartments, toxin- and cell-specific effects have also been reported. Toxins can affect resident pulmonary cells involved in alveolar fluid clearance (AFC) and barrier function through impairing vectorial Na+ transport and through cytoskeletal collapse, as such, destroying cell-cell adhesions. The resulting loss of alveolar-capillary barrier integrity and fluid clearance capacity will induce capillary leak and foster edema formation, which will in turn impair gas exchange and endanger the survival of the host. Toxins modulate or neutralize protective host cell mechanisms of both the innate and adaptive immunity response during chronic infection. In particular, toxins can either recruit or kill central players of the lung's innate immune responses to pathogenic attacks, i.e., alveolar macrophages (AMs) and neutrophils. Pulmonary disorders resulting from these toxin actions include, e.g., acute lung injury (ALI), the acute respiratory syndrome (ARDS), and severe pneumonia. When acute infection converts to persistence, i.e., colonization and chronic infection, lung diseases, such as bronchitis, chronic obstructive pulmonary disease (COPD), and cystic fibrosis (CF) can arise. The aim of this review is to discuss the impact of bacterial toxins in the lungs and the resulting outcomes for pathogenesis, their roles in promoting bacterial dissemination, and bacterial survival in disease progression.
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Affiliation(s)
- Rudolf Lucas
- Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
- Department of Medicine and Division of Pulmonary Critical Care Medicine, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
- Correspondence: (R.L.); (J.H.); Tel.: +41-31-300-35-00 (J.H.)
| | - Yalda Hadizamani
- Lungen-und Atmungsstiftung, Bern, 3012 Bern, Switzerland;
- Pneumology, Clinic for General Internal Medicine, Lindenhofspital Bern, 3012 Bern, Switzerland
| | - Joyce Gonzales
- Department of Medicine and Division of Pulmonary Critical Care Medicine, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
| | - Boris Gorshkov
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
| | - Thomas Bodmer
- Labormedizinisches Zentrum Dr. Risch, Waldeggstr. 37 CH-3097 Liebefeld, Switzerland;
| | - Yves Berthiaume
- Department of Medicine, Faculty of Medicine, Université de Montréal, Montréal, QC H3T 1J4, Canada;
| | - Ueli Moehrlen
- Pediatric Surgery, University Children’s Hospital, Zürich, Steinwiesstrasse 75, CH-8032 Zürch, Switzerland;
| | - Hartmut Lode
- Insitut für klinische Pharmakologie, Charité, Universitätsklinikum Berlin, Reichsstrasse 2, D-14052 Berlin, Germany;
| | - Hanno Huwer
- Department of Cardiothoracic Surgery, Voelklingen Heart Center, 66333 Voelklingen/Saar, Germany;
| | - Martina Hudel
- Justus-Liebig-University, Biomedical Research Centre Seltersberg, Schubertstr. 81, 35392 Giessen, Germany; (M.H.); (M.A.M.); (T.C.)
| | - Mobarak Abu Mraheil
- Justus-Liebig-University, Biomedical Research Centre Seltersberg, Schubertstr. 81, 35392 Giessen, Germany; (M.H.); (M.A.M.); (T.C.)
| | - Haroldo Alfredo Flores Toque
- Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
| | - Trinad Chakraborty
- Justus-Liebig-University, Biomedical Research Centre Seltersberg, Schubertstr. 81, 35392 Giessen, Germany; (M.H.); (M.A.M.); (T.C.)
| | - Jürg Hamacher
- Lungen-und Atmungsstiftung, Bern, 3012 Bern, Switzerland;
- Pneumology, Clinic for General Internal Medicine, Lindenhofspital Bern, 3012 Bern, Switzerland
- Medical Clinic V-Pneumology, Allergology, Intensive Care Medicine and Environmental Medicine, Faculty of Medicine, Saarland University, University Medical Centre of the Saarland, D-66421 Homburg, Germany
- Institute for Clinical & Experimental Surgery, Faculty of Medicine, Saarland University, D-66421 Homburg, Germany
- Correspondence: (R.L.); (J.H.); Tel.: +41-31-300-35-00 (J.H.)
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Secondary in-hospital epidemiological investigation after an outbreak of Pseudomonas aeruginosa ST357. J Infect Chemother 2020; 26:257-265. [DOI: 10.1016/j.jiac.2019.09.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 09/04/2019] [Accepted: 09/24/2019] [Indexed: 12/27/2022]
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Dave A, Samarth A, Karolia R, Sharma S, Karunakaran E, Partridge L, MacNeil S, Monk PN, Garg P, Roy S. Characterization of Ocular Clinical Isolates of Pseudomonas aeruginosa from Non-Contact Lens Related Keratitis Patients from South India. Microorganisms 2020; 8:microorganisms8020260. [PMID: 32075262 PMCID: PMC7074794 DOI: 10.3390/microorganisms8020260] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 02/10/2020] [Accepted: 02/13/2020] [Indexed: 12/25/2022] Open
Abstract
P. aeruginosa is the most common Gram-negative organism causing bacterial keratitis. Pseudomonas utilizes various virulence mechanisms to adhere and colonize in the host tissue. In the present study, we examined virulence factors associated with thirty-four clinical P. aeruginosa isolates collected from keratitis patients seeking care at L V Prasad Eye Institute, Hyderabad. The virulence-associated genes in all the isolates were genotyped and characteristics such as antibiotic susceptibility, biofilm formation, swarming motility, pyoverdine production and cell cytotoxicity were analyzed. All the isolates showed the presence of genes related to biofilm formation, alkaline proteases and elastases; however, there was a difference in the presence of genes related to the type III secretion system (T3SS). A higher prevalence of exoU+ genotype was noted in the drug-resistant isolates. All the isolates were capable of forming biofilms and more than 70% of the isolates showed good swarming motility. Pyoverdine production was not associated with the T3SS genotype. In the cytotoxicity assay, the presence of exoS,exoU or both resulted in higher cytotoxicity compared to the absence of both the genes. Overall, our results suggest that the T3SS profile is a good indicator of P. aeruginosa virulence characteristics and the isolates lacking the effector genes may have evolved alternate mechanisms of colonization in the host.
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Affiliation(s)
- Alpana Dave
- Prof. Brien Holden Eye Research Centre, LV Prasad Eye Institute, Hyderabad 500034, India; (A.D.); (A.S.); (P.G.)
| | - Apurwa Samarth
- Prof. Brien Holden Eye Research Centre, LV Prasad Eye Institute, Hyderabad 500034, India; (A.D.); (A.S.); (P.G.)
| | - Roshni Karolia
- Jhaveri Microbiology Centre, LV Prasad Eye Institute, Hyderabad 500034, India; (R.K.); (S.S.)
| | - Savitri Sharma
- Jhaveri Microbiology Centre, LV Prasad Eye Institute, Hyderabad 500034, India; (R.K.); (S.S.)
| | - Esther Karunakaran
- Department of Chemical and Biological Engineering, University of Sheffield, Sheffield S102TG, UK;
| | - Lynda Partridge
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S102TG, UK;
| | - Sheila MacNeil
- Department of Material Science and Engineering, University of Sheffield, Sheffield S102TG, UK;
| | - Peter N. Monk
- Department of Infection Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield S102RX, UK;
| | - Prashant Garg
- Prof. Brien Holden Eye Research Centre, LV Prasad Eye Institute, Hyderabad 500034, India; (A.D.); (A.S.); (P.G.)
| | - Sanhita Roy
- Prof. Brien Holden Eye Research Centre, LV Prasad Eye Institute, Hyderabad 500034, India; (A.D.); (A.S.); (P.G.)
- Correspondence: ; Tel.: +91-40-30612529; Fax: +91-40-30612535
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Abstract
Pseudomonas aeruginosa, a versatile Gram-negative pathogen that can cause a wide range of infections, is the most common causative agent in cases of bacterial keratitis associated with contact-lens use. Corneal infections with P. aeruginosa often have poor clinical outcomes and can result in long and costly treatments. During the infection process, the pathogen exploits its large genome, encoding complex regulatory networks and a wide range of virulence factors, including motility and the secretion of various proteases and toxins. Although antibiotic resistance levels in the UK are low, higher levels have been seen in some other countries. In the face of increasing antibiotic resistance, alternative therapeutic approaches such as antivirulence strategies and phage therapy are being developed. There is increasing evidence to suggest that keratitis infections are associated with a phylogenetic subgroup of P. aeruginosa isolates carrying the gene encoding the potent cytotoxin exotoxin U, one of two mutually exclusive exotoxins secreted via the type III secretion system. The mechanisms behind this association are unclear, but understanding the genetic differences that predispose P. aeruginosa to cause corneal infections may allow for the development of targeted and more effective future treatments to reduce the morbidity of P. aeruginosa keratitis. In order to minimize the risk of severe P. aeruginosa eye infections, a wide range of contact-lens disinfection solutions are available. Constant exposure to biocides at a range of concentrations, from sub-inhibitory to inhibitory, could contribute to the development of resistance to both antibiotics and disinfectants.
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Affiliation(s)
- Yasmin Hilliam
- Department of Clinical Infection, Microbiology, and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, L69 7BE, UK
| | - Stephen Kaye
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, L7 8TX, UK
| | - Craig Winstanley
- Department of Clinical Infection, Microbiology, and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, L69 7BE, UK
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Sawa T, Momiyama K, Mihara T, Kainuma A, Kinoshita M, Moriyama K. Molecular epidemiology of clinically high-risk Pseudomonas aeruginosa strains: Practical overview. Microbiol Immunol 2020; 64:331-344. [PMID: 31965613 DOI: 10.1111/1348-0421.12776] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 01/07/2020] [Accepted: 01/20/2020] [Indexed: 12/13/2022]
Abstract
In recent years, numerous outbreaks of multidrug-resistant Pseudomonas aeruginosa have been reported across the world. Once an outbreak occurs, besides routinely testing isolates for susceptibility to antimicrobials, it is required to check their virulence genotypes and clonality profiles. Replacing pulsed-field gel electrophoresis DNA fingerprinting are faster, easier-to-use, and less expensive polymerase chain reaction (PCR)-based methods for characterizing hospital isolates. P. aeruginosa possesses a mosaic genome structure and a highly conserved core genome displaying low sequence diversity and a highly variable accessory genome that communicates with other Pseudomonas species via horizontal gene transfer. Multiple-locus variable-number tandem-repeat analysis and multilocus sequence typing methods allow for phylogenetic analysis of isolates by PCR amplification of target genes with the support of Internet-based services. The target genes located in the core genome regions usually contain low-frequency mutations, allowing the resulting phylogenetic trees to infer evolutionary processes. The multiplex PCR-based open reading frame typing (POT) method, integron PCR, and exoenzyme genotyping can determine a genotype by PCR amplifying a specific insertion gene in the accessory genome region using a single or a multiple primer set. Thus, analyzing P. aeruginosa isolates for their clonality, virulence factors, and resistance characteristics is achievable by combining the clonality evaluation of the core genome based on multiple-locus targeting methods with other methods that can identify specific virulence and antimicrobial genes. Software packages such as eBURST, R, and Dendroscope, which are powerful tools for phylogenetic analyses, enable researchers and clinicians to visualize clonality associations in clinical isolates.
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Affiliation(s)
- Teiji Sawa
- Department of Anesthesiology, School of Medicine, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Kyoko Momiyama
- School of Pharmacy, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Toshihito Mihara
- Department of Anesthesiology, School of Medicine, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Atsushi Kainuma
- Department of Anesthesiology, School of Medicine, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Mao Kinoshita
- Department of Anesthesiology, School of Medicine, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Kiyoshi Moriyama
- Department of Anesthesiology, School of Medicine, Kyorin University, Tokyo, Japan
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