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Lucidi M, Visaggio D, Migliaccio A, Capecchi G, Visca P, Imperi F, Zarrilli R. Pathogenicity and virulence of Acinetobacter baumannii: Factors contributing to the fitness in healthcare settings and the infected host. Virulence 2024; 15:2289769. [PMID: 38054753 PMCID: PMC10732645 DOI: 10.1080/21505594.2023.2289769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 11/27/2023] [Indexed: 12/07/2023] Open
Abstract
Acinetobacter baumannii is a common cause of healthcare-associated infections and hospital outbreaks, particularly in intensive care units. Much of the success of A. baumannii relies on its genomic plasticity, which allows rapid adaptation to adversity and stress. The capacity to acquire novel antibiotic resistance determinants and the tolerance to stresses encountered in the hospital environment promote A. baumannii spread among patients and long-term contamination of the healthcare setting. This review explores virulence factors and physiological traits contributing to A. baumannii infection and adaptation to the hospital environment. Several cell-associated and secreted virulence factors involved in A. baumannii biofilm formation, cell adhesion, invasion, and persistence in the host, as well as resistance to xeric stress imposed by the healthcare settings, are illustrated to give reasons for the success of A. baumannii as a hospital pathogen.
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Affiliation(s)
- Massimiliano Lucidi
- Department of Science, Roma Tre University, Rome, Italy
- NBFC, National Biodiversity Future Center, Palermo, Italy
| | - Daniela Visaggio
- Department of Science, Roma Tre University, Rome, Italy
- NBFC, National Biodiversity Future Center, Palermo, Italy
- Santa Lucia Foundation IRCCS, Rome, Italy
| | | | | | - Paolo Visca
- Department of Science, Roma Tre University, Rome, Italy
- NBFC, National Biodiversity Future Center, Palermo, Italy
- Santa Lucia Foundation IRCCS, Rome, Italy
| | - Francesco Imperi
- Department of Science, Roma Tre University, Rome, Italy
- NBFC, National Biodiversity Future Center, Palermo, Italy
- Santa Lucia Foundation IRCCS, Rome, Italy
| | - Raffaele Zarrilli
- Department of Public Health, University of Naples Federico II, Naples, Italy
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Nasser F, Gaudreau A, Lubega S, Zaker A, Xia X, Mer AS, D'Costa VM. Characterization of the diversity of type IV secretion system-encoding plasmids in Acinetobacter. Emerg Microbes Infect 2024; 13:2320929. [PMID: 38530969 DOI: 10.1080/22221751.2024.2320929] [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: 09/14/2023] [Accepted: 02/14/2024] [Indexed: 03/28/2024]
Abstract
The multi-drug resistant pathogen Acinetobacter baumannii has gained global attention as an important clinical challenge. Owing to its ability to survive on surfaces, its capacity for horizontal gene transfer, and its resistance to front-line antibiotics, A. baumannii has established itself as a successful pathogen. Bacterial conjugation is a central mechanism for pathogen evolution. The epidemic multidrug-resistant A. baumannii ACICU harbours a plasmid encoding a Type IV Secretion System (T4SS) with homology to the E. coli F-plasmid, and plasmids with homologous gene clusters have been identified in several A. baumannii sequence types. However the genetic and host strain diversity, global distribution, and functional ability of this group of plasmids is not fully understood. Using systematic analysis, we show that pACICU2 belongs to a group of almost 120 T4SS-encoding plasmids within four different species of Acinetobacter and one strain of Klebsiella pneumoniae from human and environmental origin, and globally distributed across 20 countries spanning 4 continents. Genetic diversity was observed both outside and within the T4SS-encoding cluster, and 47% of plasmids harboured resistance determinants, with two plasmids harbouring eleven. Conjugation studies with an extensively drug-resistant (XDR) strain showed that the XDR plasmid could be successfully transferred to a more divergent A. baumanii, and transconjugants exhibited the resistance phenotype of the plasmid. Collectively, this demonstrates that these T4SS-encoding plasmids are globally distributed and more widespread among Acinetobacter than previously thought, and that they represent an important potential reservoir for future clinical concern.
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Affiliation(s)
- Farah Nasser
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada
- Centre for Infection, Immunity and Inflammation, University of Ottawa, Ottawa, Canada
| | - Avery Gaudreau
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada
- Centre for Infection, Immunity and Inflammation, University of Ottawa, Ottawa, Canada
| | - Shareefah Lubega
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada
- Centre for Infection, Immunity and Inflammation, University of Ottawa, Ottawa, Canada
| | - Arvin Zaker
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Canada
| | - Xuhua Xia
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Canada
- Department of Biology, University of Ottawa, Ottawa, Canada
| | - Arvind S Mer
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Canada
| | - Vanessa M D'Costa
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada
- Centre for Infection, Immunity and Inflammation, University of Ottawa, Ottawa, Canada
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Wang SH, Teng CK, Chan MC, Yang KY, Sheu CC, Liang SJ, Huang WH, Feng JY, Chen CM, Weng ZX, Peng CK. The impact and risk factors for developing pneumogenic bacteremia in carbapenem-resistant Acinetobacter baumannii nosocomial pneumonia in the intensive care unit: A multicenter retrospective study. Int J Infect Dis 2024; 146:107128. [PMID: 38852767 DOI: 10.1016/j.ijid.2024.107128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 06/04/2024] [Accepted: 06/04/2024] [Indexed: 06/11/2024] Open
Abstract
OBJECTIVES This study analyzed the risk and impact of developing pneumogenic bacteremia in patients with CRAB nosocomial pneumonia in ICU. METHODS This is multicenter retrospective study. Clinical outcomes were compared between bacteremia and non-bacteremia group, and the risk factors for mortality and developing pneumogenic CRAB bacteremia were analyzed. RESULTS After patient recruitment, 164 cases were in the bacteremia group, and 519 cases were in the non-bacteremia group. The bacteremia group had 22.4 percentage of increase in-hospital mortality than the non-bacteremia group (68.3% vs 45.9%, P < 0.001). Multivariate analysis showed bacteremia was an independent risk factor for in-hospital mortality (aHR = 2.399, P < 0.001). A long time-interval between ICU admission and pneumonia onset was an independent risk factor for developing bacteremia (aOR = 1.040, P = < 0.001). Spearman's rank correlation analysis indicated a high correlation between the days from ICU admission to pneumonia onset and the days of ventilator use before pneumonia onset (correlation coefficient (ρ) = 0.777). CONCLUSIONS In patients with CRAB nosocomial pneumonia, bacteremia increased the in-hospital mortality, and a longer interval from ICU admission to pneumonia onset was an independent risk factor for developing bacteremia, which was highly associated with the use of mechanical ventilation.
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Affiliation(s)
- Sheng-Huei Wang
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan; Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan
| | - Chi-Kang Teng
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan
| | - Ming-Cheng Chan
- Division of Critical Care and Respiratory Therapy, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan; National Chung Hsing University, Taichung, Taiwan
| | - Kuang-Yao Yang
- Department of Chest Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Emergency and Critical Care Medicine, School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan; Cancer and Immunology Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Chau-Chyun Sheu
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Internal Medicine, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Shinn-Jye Liang
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan
| | - Wei-Hsuan Huang
- Division of Infectious Diseases, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan
| | - Jia-Yih Feng
- Department of Chest Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Chia-Min Chen
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Zi-Xeng Weng
- Department of Medical Research, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Chung-Kan Peng
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan; Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
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Duller S, Kumpitsch C, Moissl-Eichinger C, Wink L, Koskinen Mora K, Mahnert A. In-hospital areas with distinct maintenance and staff/patient traffic have specific microbiome profiles, functions, and resistomes. mSystems 2024; 9:e0072624. [PMID: 38980054 PMCID: PMC11334533 DOI: 10.1128/msystems.00726-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Accepted: 06/11/2024] [Indexed: 07/10/2024] Open
Abstract
Hospitals are subject to strict microbial control. Stringent cleaning and confinement measures in hospitals lead to a decrease in microbial diversity, but an increase in resistance genes. Given the rise of antimicrobial resistances and healthcare-associated infections, understanding the hospital microbiome and its resistome is crucial. This study compared the microbiome and resistome at different levels of confinement (CL) within a single hospital. Using amplicon sequencing, shotgun metagenomics, and genome/plasmid reconstruction, we demonstrate that microbial composition differs in a stable way between the CLs and that the most restrictive confinement level CL1 had the lowest microbial but the highest functional diversity. This CL also exhibited a greater abundance of functions related to virulence, disease, defense, and stress response. Comparison of antibiotic resistance also showed differences among CLs in terms of the selection process and specific mechanisms for antimicrobial/antibiotic resistance. The resistances found in the samples of CL1 were mostly mediated via antibiotic efflux pumps and were mainly located on chromosomes, whereas in the other, less restrictive CL antibiotic resistances were more present on plasmids. This could be of particular importance for patient-related areas (CL2), as the potential spread of antibiotic resistances could be a major concern in this area. Our results show that there are differences in the microbiome and resistome even within a single hospital, reflecting room utilization and confinement. Since restrictive confinement selects for resistant microorganisms, strategies are required to deepen our understanding of dynamic processes of microbiome and resistome within hospital environments. IMPORTANCE Effective measures to combat antibiotic resistances and healthcare-associated infections are urgently needed, including optimization of microbial control. However, previous studies have indicated that stringent control can lead to an increase in the resistance capacities of microbiomes on surfaces. This study adds to previous knowledge by focusing on the conditions in a single hospital, resolving the microbiomes and their resistomes in three different confinement levels (CL): operating room, patient-related areas, and non-patient-related areas. We were able to identify stable key taxa; profiled the capacities of taxa, functions, and antimicrobial resistances (AMR); and reconstruct genomes and plasmids in each CL. Our results show that the most restrictive CL indeed had the highest functional diversity, but that resistances were mostly encoded on chromosomes, indicating a lower possibility of resistance spread. However, clever strategies are still required to strike a balance between microbial control and selective pressures in environments where patients need protection.
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Affiliation(s)
- Stefanie Duller
- D&R Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Graz, Austria
| | - Christina Kumpitsch
- D&R Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Graz, Austria
- BioTechMed Graz, Graz, Austria
| | - Christine Moissl-Eichinger
- D&R Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Graz, Austria
- BioTechMed Graz, Graz, Austria
| | - Lisa Wink
- D&R Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Graz, Austria
| | - Kaisa Koskinen Mora
- D&R Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Graz, Austria
| | - Alexander Mahnert
- D&R Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Graz, Austria
- BioTechMed Graz, Graz, Austria
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Nabi B, Kumawat M, Ahlawat N, Ahlawat S. Molecular, Structural, and Functional Diversity of Universal Stress Proteins (USPs) in Bacteria, Plants, and Their Biotechnological Applications. Protein J 2024; 43:437-446. [PMID: 38492187 DOI: 10.1007/s10930-024-10192-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/08/2024] [Indexed: 03/18/2024]
Abstract
Universal stress proteins (USPs) are widely distributed and play crucial roles in cellular responses to biotic and abiotic stresses. These roles include regulating cell growth and development, cell motility, hypoxia responses, and ion sequestration. With the increasing frequency and intensity of extreme weather events due to climate change, pathogens have developed different strategies to withstand environmental stresses, in which USPs play a significant role in their survival and virulence. In this study, we analyzed the importance of USPs in various organisms, such as archaea, plants, and fungi, as a parameter that influences their survival. We discussed the different types Of USPs and their role, aiming to carry out fundamental research in this field to identify significant constraints for better understanding of USP functions at molecular level. Additionally, we discussed concepts and research techniques that could help overcome these hurdles and facilitate new molecular approaches to better understand and target USPs as important stress adaptation and survival regulators. Although the precise characteristics of USPs are still unclear, numerous innovative uses have already been developed, tested, and implemented. Complementary approaches to basic research and applications, as well as new technology and analytical techniques, may offer insights into the cryptic but crucial activities of USPs in various living systems.
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Affiliation(s)
- Bilkees Nabi
- Department of Biochemistry & Biochemical Engineering, SHUATS, Allahabad, 211007, India
| | - Manoj Kumawat
- Department of Microbiology, ICMR- National Institute for Research in Environmental Health, Bhopal, 462030, India.
- Department of Biological Sciences, Indian Institute of Science Education and Research, Bhopal, 462066, Madhya Pradesh, India.
| | - Neeraj Ahlawat
- Department of Animal Husbandry and Dairying, SHUATS, Allahabad, 211007, India
| | - Sushma Ahlawat
- Department of Biochemistry & Biochemical Engineering, SHUATS, Allahabad, 211007, India.
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Mahdally NH, ElShiekh RA, Thissera B, Eltaher A, Osama A, Mokhtar M, Elhosseiny NM, Kashef MT, Magdeldin S, El Halawany AM, Rateb ME, Attia AS. Dihydrophenazine: a multifunctional new weapon that kills multidrug-resistant Acinetobacter baumannii and restores carbapenem and oxidative stress susceptibilities. J Appl Microbiol 2024; 135:lxae100. [PMID: 38627251 DOI: 10.1093/jambio/lxae100] [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: 03/13/2024] [Revised: 04/10/2024] [Accepted: 04/15/2024] [Indexed: 05/02/2024]
Abstract
AIMS The current work aims to fully characterize a new antimicrobial agent against Acinetobacter baumannii, which continues to represent a growing threat to healthcare settings worldwide. With minimal treatment options due to the extensive spread of resistance to almost all the available antimicrobials, the hunt for new antimicrobial agents is a high priority. METHODS AND RESULTS An Egyptian soil-derived bacterium strain NHM-077B proved to be a promising source for a new antimicrobial agent. Bio-guided fractionation of the culture supernatants of NHM-077B followed by chemical structure elucidation identified the active antimicrobial agent as 1-hydroxy phenazine. Chemical synthesis yielded more derivatives, including dihydrophenazine (DHP), which proved to be the most potent against A. baumannii, yet it exhibited a marginally safe cytotoxicity profile against human skin fibroblasts. Proteomics analysis of the cells treated with DHP revealed multiple proteins with altered expression that could be correlated to the observed phenotypes and potential mechanism of the antimicrobial action of DHP. DHP is a multipronged agent that affects membrane integrity, increases susceptibility to oxidative stress, interferes with amino acids/protein synthesis, and modulates virulence-related proteins. Interestingly, DHP in subinhibitory concentrations re-sensitizes the highly virulent carbapenem-resistant A. baumannii strain AB5075 to carbapenems providing great hope in regaining some of the benefits of this important class of antibiotics. CONCLUSIONS This work underscores the potential of DHP as a promising new agent with multifunctional roles as both a classical and nonconventional antimicrobial agent that is urgently needed.
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Affiliation(s)
- Norhan H Mahdally
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo 11562, Egypt
| | - Riham A ElShiekh
- Department of Pharmacognosy, Faculty of Pharmacy, Cairo University, Cairo 11562, Egypt
| | - Bathini Thissera
- School of Computing, Engineering and Physical Sciences, University of the West of Scotland, Paisley PA1 2BE, United Kingdom
| | - Ashraf Eltaher
- Proteomics and Metabolomics Research Program, Basic Research Department, Children's Cancer Hospital, Cairo 57357, Egypt
| | - Aya Osama
- Proteomics and Metabolomics Research Program, Basic Research Department, Children's Cancer Hospital, Cairo 57357, Egypt
| | - Maha Mokhtar
- Proteomics and Metabolomics Research Program, Basic Research Department, Children's Cancer Hospital, Cairo 57357, Egypt
| | - Noha M Elhosseiny
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo 11562, Egypt
| | - Mona T Kashef
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo 11562, Egypt
| | - Sameh Magdeldin
- Proteomics and Metabolomics Research Program, Basic Research Department, Children's Cancer Hospital, Cairo 57357, Egypt
- Department of Physiology, Faculty of Veterinary Medicine, Suez Canal University, Ismailia 41522, Egypt
| | - Ali M El Halawany
- Department of Pharmacognosy, Faculty of Pharmacy, Cairo University, Cairo 11562, Egypt
| | - Mostafa E Rateb
- School of Computing, Engineering and Physical Sciences, University of the West of Scotland, Paisley PA1 2BE, United Kingdom
| | - Ahmed S Attia
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo 11562, Egypt
- School of Pharmacy, Newgiza University, Giza 12585, Egypt
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Sabry MM, El-Halawany AM, Fahmy WG, Eltanany BM, Pont L, Benavente F, Attia AS, Sherbiny FF, Ibrahim RM. Evidence on the inhibitory effect of Brassica plants against Acinetobacter baumannii lipases: phytochemical analysis, in vitro, and molecular docking studies. BMC Complement Med Ther 2024; 24:164. [PMID: 38641582 PMCID: PMC11027383 DOI: 10.1186/s12906-024-04460-y] [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: 01/02/2024] [Accepted: 03/28/2024] [Indexed: 04/21/2024] Open
Abstract
BACKGROUND Infections caused by Acinetobacter baumannii are becoming a rising public health problem due to its high degree of acquired and intrinsic resistance mechanisms. Bacterial lipases penetrate and damage host tissues, resulting in multiple infections. Because there are very few effective inhibitors of bacterial lipases, new alternatives for treating A. baumannii infections are urgently needed. In recent years, Brassica vegetables have received a lot of attention since their phytochemical compounds have been directly linked to diverse antimicrobial actions by inhibiting the growth of various Gram-positive and Gram-negative bacteria, yeast, and fungi. Despite their longstanding antibacterial history, there is currently a lack of scientific evidence to support their role in the management of infections caused by the nosocomial bacterium, A. baumannii. This study aimed to address this gap in knowledge by examining the antibacterial and lipase inhibitory effects of six commonly consumed Brassica greens, Chinese cabbage (CC), curly and Tuscan kale (CK and TK), red and green Pak choi (RP and GP), and Brussels sprouts (BR), against A. baumannii in relation to their chemical profiles. METHODS The secondary metabolites of the six extracts were identified using LC-QTOF-MS/MS analysis, and they were subsequently correlated with the lipase inhibitory activity using multivariate data analysis and molecular docking. RESULTS In total, 99 metabolites from various chemical classes were identified in the extracts. Hierarchical cluster analysis (HCA) and principal component analysis (PCA) revealed the chemical similarities and variabilities among the specimens, with glucosinolates and phenolic compounds being the major metabolites. RP and GP showed the highest antibacterial activity against A. baumannii, followed by CK. Additionally, four species showed a significant effect on the bacterial growth curves and demonstrated relevant inhibition of A. baumannii lipolytic activity. CK showed the greatest inhibition (26%), followed by RP (21%), GP (21%), and TK (15%). Orthogonal partial least squares-discriminant analysis (OPLS-DA) pinpointed 9 metabolites positively correlated with the observed bioactivities. Further, the biomarkers displayed good binding affinities towards lipase active sites ranging from -70.61 to -30.91 kcal/mol, compared to orlistat. CONCLUSION This study emphasizes the significance of Brassica vegetables as a novel natural source of potential inhibitors of lipase from A. baumannii.
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Affiliation(s)
- Manal M Sabry
- Department of Pharmacognosy, Faculty of Pharmacy, Cairo University, Cairo, 11562, Egypt
| | - Ali M El-Halawany
- Department of Pharmacognosy, Faculty of Pharmacy, Cairo University, Cairo, 11562, Egypt
| | - Walaa G Fahmy
- Department of Microbiology & Immunology, Faculty of Pharmacy, Cairo University, Cairo, 11562, Egypt
| | - Basma M Eltanany
- Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Cairo University, Cairo, 11562, Egypt
| | - Laura Pont
- Department of Chemical Engineering and Analytical Chemistry, Institute for Research on Nutrition and Food Safety (INSA·UB), University of Barcelona, Barcelona, 08028, Spain
- Serra Húnter Program, Generalitat de Catalunya, Barcelona, 08007, Spain
| | - Fernando Benavente
- Department of Chemical Engineering and Analytical Chemistry, Institute for Research on Nutrition and Food Safety (INSA·UB), University of Barcelona, Barcelona, 08028, Spain
| | - Ahmed S Attia
- Department of Microbiology & Immunology, Faculty of Pharmacy, Cairo University, Cairo, 11562, Egypt
- School of Pharmacy, Newgiza University, Giza, 12577, Egypt
| | - Farag F Sherbiny
- Pharmaceutical Organic Chemistry Department, Faculty of Pharmacy, Al-Azhar University, Nasr city, Cairo, 11884, Egypt
| | - Rana M Ibrahim
- Department of Pharmacognosy, Faculty of Pharmacy, Cairo University, Cairo, 11562, Egypt.
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Yan T, Li M, Wang Q, Wang M, Liu L, Ma C, Xiang X, Zhou Q, Liu Z, Gong Z. Structures, functions, and regulatory networks of universal stress proteins in clinically relevant pathogenic Bacteria. Cell Signal 2024; 116:111032. [PMID: 38185228 DOI: 10.1016/j.cellsig.2023.111032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 12/14/2023] [Accepted: 12/30/2023] [Indexed: 01/09/2024]
Abstract
Universal stress proteins are a class of proteins widely present in bacteria, archaea, plants, and invertebrates, playing essential roles in bacterial adaptation to various environmental stresses. The functions of bacterial universal stress proteins are versatile, including resistance to oxidative stress, maintenance of cell wall integrity, DNA damage repair, regulation of cell division and growth, among others. When facing stresses such as temperature changes, pH shifts, fluctuations in oxygen concentration, and exposure to toxins, these proteins can bind to specific DNA sequences and rapidly adjust bacterial metabolic pathways and gene expression patterns to adapt to the new environment. In summary, bacterial universal stress proteins play a crucial role in bacterial adaptability and survival. A comprehensive understanding of bacterial stress response mechanisms and the development of new antibacterial strategies are of great significance. This review summarizes the research progress on the structure, function, and regulatory factors of universal stress proteins in clinically relevant bacteria, aiming to facilitate deeper investigations by clinicians and researchers into universal stress proteins.
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Affiliation(s)
- Tao Yan
- Department of Clinical Laboratory, The Second Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Min Li
- Department of Clinical Laboratory, The Second Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Qiuyan Wang
- Department of Clinical Laboratory, The Second Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Meng Wang
- Department of Clinical Laboratory, The Second Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Lijuan Liu
- Department of Clinical Laboratory, The Second Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Chengcheng Ma
- Department of Clinical Laboratory, The Second Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Xiaohong Xiang
- School of Pharmacy, Chongqing Medical and Pharmaceutical College, Chongqing, China
| | - Qiang Zhou
- Department of Clinical Laboratory, The Second Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Zhou Liu
- Department of Clinical Laboratory, The Second Affiliated Hospital of Anhui Medical University, Hefei, China.
| | - Zhen Gong
- Department of Clinical Laboratory, The Second Affiliated Hospital of Anhui Medical University, Hefei, China.
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Bae JY, Yun I, Jun KI, Kim CJ, Lee M, Choi HJ. Association between Pneumonia Development and Virulence Gene Expression in Carbapenem-Resistant Acinetobacter baumannii Isolated from Clinical Specimens. THE CANADIAN JOURNAL OF INFECTIOUS DISEASES & MEDICAL MICROBIOLOGY = JOURNAL CANADIEN DES MALADIES INFECTIEUSES ET DE LA MICROBIOLOGIE MEDICALE 2023; 2023:8265683. [PMID: 38156310 PMCID: PMC10754638 DOI: 10.1155/2023/8265683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 11/15/2023] [Accepted: 12/13/2023] [Indexed: 12/30/2023]
Abstract
We investigated the virulence gene expression of carbapenem-resistant Acinetobacter baumanii (CRAB) isolated from the respiratory samples of patients with CRAB pneumonia and those with CRAB colonization to identify the virulence genes contributing to CRAB pneumonia's development and mortality. Patients with CRAB identified from respiratory specimens were screened at a tertiary university hospital between January 2018 and January 2019. Patients were classified into CRAB pneumonia or CRAB colonization groups according to predefined clinical criteria. A. baumannii isolated from respiratory specimens was examined for the expression levels of ompA, uspA, hfq, hisF, feoA, and bfnL by quantitative reverse-transcription polymerase chain reaction. Among 156 patients with CRAB from respiratory specimens, 17 and 24 met the criteria for inclusion in the pneumonia and colonization groups, respectively. The expression level of ompA was significantly higher in the pneumonia group than in the colonization group (1.45 vs. 0.63, P=0.03). The expression levels of ompA (1.97 vs. 0.86, P=0.02), hisF (1.06 vs. 0.10, P < 0.01), uspA (1.62 vs. 1.01, P < 0.01), and bfnL (3.14 vs. 2.14, P=0.03) were significantly higher in patients with 30-day mortality than in the surviving patients. Elevated expression of hisF (adjusted odds ratio = 5.93, P=0.03) and uspA (adjusted odds ratio = 7.36, P=0.02) were associated with 30-day mortality after adjusting for age and the Charlson score. uspA and hisF may serve as putative targets for novel therapeutic strategies.
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Affiliation(s)
- Ji Yun Bae
- Department of Internal Medicine, Ewha Womans University Mokdong Hospital, Seoul, Republic of Korea
- Ewha Education and Research Center for Infection, Seoul, Republic of Korea
- Department of Internal Medicine, Ewha Womans University Seoul Hospital, Seoul, Republic of Korea
| | - Ina Yun
- Ewha Education and Research Center for Infection, Seoul, Republic of Korea
| | - Kang Il Jun
- Ewha Education and Research Center for Infection, Seoul, Republic of Korea
- Department of Internal Medicine, Ewha Womans University Seoul Hospital, Seoul, Republic of Korea
| | - Chung-Jong Kim
- Ewha Education and Research Center for Infection, Seoul, Republic of Korea
- Department of Internal Medicine, Ewha Womans University Seoul Hospital, Seoul, Republic of Korea
| | - Miae Lee
- Ewha Education and Research Center for Infection, Seoul, Republic of Korea
- Department of Laboratory Medicine, Ewha Womans University Mokdong Hospital, Seoul, Republic of Korea
- Department of Laboratory Medicine, Seegene Medical Foundation, Seoul, Republic of Korea
| | - Hee Jung Choi
- Department of Internal Medicine, Ewha Womans University Mokdong Hospital, Seoul, Republic of Korea
- Ewha Education and Research Center for Infection, Seoul, Republic of Korea
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Luo D, Wu Z, Bai Q, Zhang Y, Huang M, Huang Y, Li X. Universal Stress Proteins: From Gene to Function. Int J Mol Sci 2023; 24:ijms24054725. [PMID: 36902153 PMCID: PMC10003552 DOI: 10.3390/ijms24054725] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 02/23/2023] [Accepted: 02/23/2023] [Indexed: 03/05/2023] Open
Abstract
Universal stress proteins (USPs) exist across a wide range of species and are vital for survival under stressful conditions. Due to the increasingly harsh global environmental conditions, it is increasingly important to study the role of USPs in achieving stress tolerance. This review discusses the role of USPs in organisms from three aspects: (1) organisms generally have multiple USP genes that play specific roles at different developmental periods of the organism, and, due to their ubiquity, USPs can be used as an important indicator to study species evolution; (2) a comparison of the structures of USPs reveals that they generally bind ATP or its analogs at similar sequence positions, which may underlie the regulatory role of USPs; and (3) the functions of USPs in species are diverse, and are generally directly related to the stress tolerance. In microorganisms, USPs are associated with cell membrane formation, whereas in plants they may act as protein chaperones or RNA chaperones to help plants withstand stress at the molecular level and may also interact with other proteins to regulate normal plant activities. This review will provide directions for future research, focusing on USPs to provide clues for the development of stress-tolerant crop varieties and for the generation of novel green pesticide formulations in agriculture, and to better understand the evolution of drug resistance in pathogenic microorganisms in medicine.
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O'Connor A, Jurado‐Martín I, Mysior MM, Manzira AL, Drabinska J, Simpson JC, Lucey M, Schaffer K, Berisio R, McClean S. A universal stress protein upregulated by hypoxia has a role in Burkholderia cenocepacia intramacrophage survival: Implications for chronic infection in cystic fibrosis. Microbiologyopen 2023; 12:e1311. [PMID: 36825886 PMCID: PMC9733578 DOI: 10.1002/mbo3.1311] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 07/29/2022] [Accepted: 07/29/2022] [Indexed: 12/13/2022] Open
Abstract
Universal stress proteins (USPs) are ubiquitously expressed in bacteria, archaea, and eukaryotes and play a lead role in adaptation to environmental conditions. They enable adaptation of bacterial pathogens to the conditions encountered in the human niche, including hypoxia, oxidative stress, osmotic stress, nutrient deficiency, or acid stress, thereby facilitating colonization. We previously reported that all six USP proteins encoded within a low-oxygen activated (lxa) locus in Burkholderia cenocepacia showed increased abundance during chronic colonization of the cystic fibrosis (CF) lung. However, the role of USPs in chronic cystic fibrosis infection is not well understood. Structural modeling identified surface arginines on one lxa-encoded USP, USP76, which suggested it mediated interactions with heparan sulfate. Using mutants derived from the B. cenocepacia strain, K56-2, we show that USP76 is involved in host cell attachment. Pretreatment of lung epithelial cells with heparanase reduced the binding of the wild-type and complement strains but not the Δusp76 mutant strain, indicating that USP76 is directly or indirectly involved in receptor recognition on the surface of epithelial cells. We also show that USP76 is required for growth and survival in many conditions associated with the CF lung, including acidic conditions and oxidative stress. Moreover, USP76 also has a role in survival in macrophages isolated from people with CF. Overall, while further elucidation of the exact mechanism(s) is required, we can conclude that USP76, which is upregulated during chronic infection, is involved in bacterial survival within CF macrophages, a hallmark of Burkholderia infection.
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Affiliation(s)
- Andrew O'Connor
- School of Biomolecular and Biomedical SciencesUniversity College DublinBelfieldDublinIreland
| | - Irene Jurado‐Martín
- School of Biomolecular and Biomedical SciencesUniversity College DublinBelfieldDublinIreland
- UCD Conway Institute of Biomolecular and Biomedical ScienceBefieldDublinIreland
| | - Margaritha M. Mysior
- UCD Conway Institute of Biomolecular and Biomedical ScienceBefieldDublinIreland
- Cell Screening Laboratory, School of Biology and Environmental ScienceUniversity College DublinBelfieldDublinIreland
| | - Anotidaishe L. Manzira
- School of Biomolecular and Biomedical SciencesUniversity College DublinBelfieldDublinIreland
- UCD Conway Institute of Biomolecular and Biomedical ScienceBefieldDublinIreland
| | - Joanna Drabinska
- School of Biomolecular and Biomedical SciencesUniversity College DublinBelfieldDublinIreland
- UCD Conway Institute of Biomolecular and Biomedical ScienceBefieldDublinIreland
| | - Jeremy C. Simpson
- UCD Conway Institute of Biomolecular and Biomedical ScienceBefieldDublinIreland
- Cell Screening Laboratory, School of Biology and Environmental ScienceUniversity College DublinBelfieldDublinIreland
| | - Mary Lucey
- Department of MicrobiologySt. Vincent's University HospitalElm ParkDublinIreland
| | - Kirsten Schaffer
- Department of MicrobiologySt. Vincent's University HospitalElm ParkDublinIreland
| | - Rita Berisio
- Institute of Biostructures and BioimagingNational Research CouncilNaplesItaly
| | - Siobhán McClean
- School of Biomolecular and Biomedical SciencesUniversity College DublinBelfieldDublinIreland
- UCD Conway Institute of Biomolecular and Biomedical ScienceBefieldDublinIreland
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12
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Mohamad F, Alzahrani RR, Alsaadi A, Alrfaei BM, Yassin AEB, Alkhulaifi MM, Halwani M. An Explorative Review on Advanced Approaches to Overcome Bacterial Resistance by Curbing Bacterial Biofilm Formation. Infect Drug Resist 2023; 16:19-49. [PMID: 36636380 PMCID: PMC9830422 DOI: 10.2147/idr.s380883] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 12/06/2022] [Indexed: 01/05/2023] Open
Abstract
The continuous emergence of multidrug-resistant pathogens evoked the development of innovative approaches targeting virulence factors unique to their pathogenic cascade. These approaches aimed to explore anti-virulence or anti-infective therapies. There are evident concerns regarding the bacterial ability to create a superstructure, the biofilm. Biofilm formation is a crucial virulence factor causing difficult-to-treat, localized, and systemic infections. The microenvironments of bacterial biofilm reduce the efficacy of antibiotics and evade the host's immunity. Producing a biofilm is not limited to a specific group of bacteria; however, Pseudomonas aeruginosa, Acinetobacter baumannii, and Staphylococcus aureus biofilms are exemplary models. This review discusses biofilm formation as a virulence factor and the link to antimicrobial resistance. In addition, it explores insights into innovative multi-targeted approaches and their physiological mechanisms to combat biofilms, including natural compounds, phages, antimicrobial photodynamic therapy (aPDT), CRISPR-Cas gene editing, and nano-mediated techniques.
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Affiliation(s)
- F Mohamad
- Infectious Diseases Research Department, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Raghad R Alzahrani
- Nanomedicine Department, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia,Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia
| | - Ahlam Alsaadi
- Infectious Diseases Research Department, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Bahauddeen M Alrfaei
- Stem Cells and Regenerative Medicine, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Alaa Eldeen B Yassin
- College of Pharmacy, King Saud bin Abdulaziz University for Health Sciences, King Abdullah International Medical Research Center, Riyadh, Saudi Arabia
| | - Manal M Alkhulaifi
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia,Manal M Alkhulaifi, P.O. Box 55670, Riyadh, 11544, Tel +966 (11) 805-1685, Email
| | - Majed Halwani
- Nanomedicine Department, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia,Correspondence: Majed Halwani, P.O. Box 3660, Mail Code 1515 (KAIMRC), Riyadh, 11481, Tel +966 (11) 429-4433, Fax +966 (11) 429-4440, Email ;
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13
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M S, N RP, Rajendrasozhan S. Bacterial redox response factors in the management of environmental oxidative stress. World J Microbiol Biotechnol 2022; 39:11. [PMID: 36369499 DOI: 10.1007/s11274-022-03456-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 11/02/2022] [Indexed: 11/13/2022]
Abstract
Bacteria evolved to survive in the available environmental chemosphere via several cellular mechanisms. A rich pool of antioxidants and stress regulators plays a significant role in the survival of bacteria in unfavorable environmental conditions. Most of the microbes exhibit resistant phenomena in toxic environment niches. Naturally, bacteria possess efficient thioredoxin reductase, glutaredoxin, and peroxiredoxin redox systems to handle environmental oxidative stress. Further, an array of transcriptional regulators senses the oxidative stress conditions. Transcription regulators, such as OxyR, SoxRS, PerR, UspA, SsrB, MarA, OhrR, SarZ, etc., sense and transduce bacterial oxidative stress responses. The redox-sensitive transcription regulators continuously recycle the utilized antioxidant enzymes during oxidative stress. These regulators promote the expression of antioxidant enzymes such as superoxide dismutase, catalase, and peroxides that overcome oxidative insults. Therefore, the transcriptional regulations maintain steady-state activities of antioxidant enzymes representing the resistance against host cell/environmental oxidative insults. Further, the redox system provides reducing equivalents to synthesize biomolecules, thereby contributing to cellular repair mechanisms. The inactive transcriptional regulators in the undisturbed cells are activated by oxidative stress. The oxidized transcriptional regulators modulate the expression of antioxidant and cellular repair enzymes to survive in extreme environmental conditions. Therefore, targeting these antioxidant systems and response regulators could alter cellular redox homeostasis. This review presents the mechanisms of different redox systems that favor bacterial survival in extreme environmental oxidative stress conditions.
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Affiliation(s)
- Sudharsan M
- Department of Biochemistry and Biotechnology, Annamalai University, Annamalainagar, Chidambaram, Tamil Nadu, 608 002, India
| | - Rajendra Prasad N
- Department of Biochemistry and Biotechnology, Annamalai University, Annamalainagar, Chidambaram, Tamil Nadu, 608 002, India.
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14
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Oda Y, Shapiro MM, Lewis NM, Zhong X, Huse HK, Zhong W, Bruce JE, Manoil C, Harwood CS. CsrA-Controlled Proteins Reveal New Dimensions of Acinetobacter baumannii Desiccation Tolerance. J Bacteriol 2022; 204:e0047921. [PMID: 35285725 PMCID: PMC9017300 DOI: 10.1128/jb.00479-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 01/24/2022] [Indexed: 12/19/2022] Open
Abstract
Hospital environments are excellent reservoirs for the opportunistic pathogen Acinetobacter baumannii in part because it is exceptionally tolerant to desiccation. We found that relative to other A. baumannii strains, the virulent strain AB5075 was strikingly desiccation resistant at 2% relative humidity (RH), suggesting that it is a good model for studies of the functional basis of this trait. Consistent with results from other A. baumannii strains at 40% RH, we found the global posttranscriptional regulator CsrA to be critically important for desiccation tolerance of AB5075 at 2% RH. Proteomics experiments identified proteins that were differentially present in wild-type and csrA mutant cells. Subsequent analysis of mutants in genes encoding some of these proteins revealed six genes that were required for wild-type levels of desiccation tolerance. These include genes for catalase, a universal stress protein, a hypothetical protein, and a biofilm-associated protein. Two genes of unknown function had very strong desiccation phenotypes, with one of the two genes predicting an intrinsically disordered protein (IDP) that binds to DNA. Intrinsically disordered proteins are widespread in eukaryotes but less so in prokaryotes. Our results suggest there are new mechanisms underlying desiccation tolerance in bacteria and identify several key functions involved. IMPORTANCE Acinetobacter baumannii is found in terrestrial environments but can cause nosocomial infections in very sick patients. A factor that contributes to the prevalence of A. baumannii in hospital settings is that it is intrinsically resistant to dry conditions. Here, we established the virulent strain A. baumannii AB5075 as a model for studies of desiccation tolerance at very low relative humidity. Our results show that this trait depends on two proteins of unknown function, one of which is predicted to be an intrinsically disordered protein. This category of protein is critical for the small animals named tardigrades to survive desiccation. Our results suggest that A. baumannii may have novel strategies to survive desiccation that have not previously been seen in bacteria.
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Affiliation(s)
- Yasuhiro Oda
- Department of Microbiology, University of Washington, Seattle, Washington, USA
| | - Madelyn M. Shapiro
- Seattle Children’s Research Institute, Center for Global Infectious Disease Research, Seattle, Washington, USA
| | - Nathan M. Lewis
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul, Minnesota, USA
| | - Xuefei Zhong
- Analytical Chemistry Group, Regeneron Pharmaceuticals, Tarrytown, New York, USA
| | - Holly K. Huse
- Department of Pathology, Harbor-UCLA Medical Center, Torrance, California, USA
| | - Weizhi Zhong
- Department of Microbiology, University of Washington, Seattle, Washington, USA
| | - James E. Bruce
- Department of Genome Sciences, University of Washington, Seattle, Washington, USA
| | - Colin Manoil
- Department of Genome Sciences, University of Washington, Seattle, Washington, USA
| | - Caroline S. Harwood
- Department of Microbiology, University of Washington, Seattle, Washington, USA
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15
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Squire MS, Townsend HA, Actis LA. The Influence of Blue Light and the BlsA Photoreceptor on the Oxidative Stress Resistance Mechanisms of Acinetobacter baumannii. Front Cell Infect Microbiol 2022; 12:856953. [PMID: 35402311 PMCID: PMC8987720 DOI: 10.3389/fcimb.2022.856953] [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: 01/17/2022] [Accepted: 02/25/2022] [Indexed: 11/13/2022] Open
Abstract
Acinetobacter baumannii is a catalase-positive Gram-negative bacterial pathogen that causes severe infections among compromised patients. Among its noteworthy regulatory mechanisms, this microorganism regulates its lifestyle through the blue light using flavin (BLUF) protein BlsA. This protein regulates a diverse set of cellular processes that include, but are not limited to, motility, biofilm formation, phenylacetic acid metabolism, iron uptake, and catalase activity. We set out to determine how A. baumannii regulates catalase activity and other related oxidative stress phenotypes in response to light. Notably, because A. baumannii ATCC 17978 encodes four catalase homologs – which we refer to as KatA, KatE, KatE2, and KatG – we also aimed to show which of these enzymes exhibit light- and BlsA-dependent activity. Our work not only provides insight into the general function of all four catalase homologs and the impact of light on these functions, but also directly identifies KatE as a BlsA-regulated enzyme. We further demonstrate that the regulation of KatE by BlsA is dependent on a lysine residue that we previously demonstrated to be necessary for the regulation of surface motility. Furthermore, we show that BlsA’s five most-C-terminal residues – previously considered dispensable for BlsA’s overall function – are necessary for the light-independent and light-dependent regulation of catalase and superoxide dismutase activities, respectively. We hypothesize that these identified critical residues are necessary for BlsA’s interaction with protein partners including the transcriptional regulators Fur and BfmR. Together these data expand the understanding regarding how A. baumannii uses light as a signal to control oxidative stress resistance mechanisms that are critical for its pathophysiology.
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16
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Yan J, Sun D, Kuang X, Liang M, Luo L. Quantitative proteomic analysis reveals the metabolic characteristics and adaptive mechanism of Cupriavidus oxalaticus T2 in the process of simultaneous nitrogen and phenol removal. J Proteomics 2022; 251:104426. [PMID: 34781029 DOI: 10.1016/j.jprot.2021.104426] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 10/07/2021] [Accepted: 11/06/2021] [Indexed: 11/20/2022]
Abstract
Phenol and ammonia in wastewater pose a serious threat to ecosystems and human health. However, the currently limited studies on single bacterium simultaneously removing phenol and nitrogen pollution have not fully elucidated the relevant metabolic mechanisms. The differences in proteomic profile after supplementing with phenol and ammonia for 6 and 24 h, respectively, were evaluated to explore the metabolic characteristics and adaptive mechanism of Cupriavidus oxalaticus T2 during the simultaneous removal process of phenol and nitrogen. Results revealed that a new potential phenol para-degradation pathway appeared in T2. Phenol induced changes in nitrogen metabolism, resulting in increased denitrification and decreased synthesis of glutamate from ammonia at 6 h. In addition, phenol exposure enhanced the expression of cytochrome oxidases with high oxygen affinity and increased ATP synthesis. The increase in chemotaxis and flagellar assembly was conducive to the uptake and utilization of phenol. The synthesis of lipoic acid and biotin was also promoted to resist phenol toxicity. Moreover, phenol triggered cellular stress response, thereby leading to the upregulation of anti-stress proteins, such as universal stress protein, iron‑sulfur cluster protein, and chaperones. This study contributes to revealing the metabolic characteristics and adaptive mechanism of T2 during simultaneous nitrogen and phenol removal. SIGNIFICANCE: Phenol and ammonia often co-exist in wastewater, causing serious environmental problems. The information on the metabolic mechanism of simultaneously removing these two pollutants by bacteria is insufficient at present. Moreover, phenol is toxic to microbial and causes cells damage. Therefore, exploring the response mechanism of bacteria to phenol stress is conducive to understand their tolerance mechanism to aromatic compounds. In this study, the metabolic characteristics and adaptive mechanism of C. oxalaticus T2 during the simultaneous removal of phenol and nitrogen process were evaluated by comparing the proteome profiles at different stages. The results revealed the degradation pathways of phenol and nitrogen by strain T2. A variety of phenol response mechanisms were determined, including enhanced energy production, improved cell motility, increased the synthesis of lipoic acid and biotin, and combined action of multiple anti-stress proteins. This study is potentially useful to future phenol and nitrogen co-pollution bioremediation strategies and provides insight into the phenolic compound resistance mechanism in bacteria.
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Affiliation(s)
- Junwei Yan
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, PR China; Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou 510006, PR China
| | - Dongdong Sun
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, PR China; Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou 510006, PR China
| | - Xiaoxian Kuang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, PR China; Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou 510006, PR China
| | - Minghua Liang
- School of Food Science and Engineering, South China University of Technology, 381 Wushan Road, Guangzhou, Guangdong 510640, PR China
| | - Lixin Luo
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, PR China; Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou 510006, PR China.
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17
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Bandyopadhyay D, Mukherjee M. Combination of bactericidal antibiotics and inhibitors of Universal stress protein A (UspA): a potential therapeutic alternative against multidrug resistant Escherichia coli in urinary tract infections. J Antibiot (Tokyo) 2022; 75:21-28. [PMID: 34526667 DOI: 10.1038/s41429-021-00477-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 08/04/2021] [Accepted: 08/16/2021] [Indexed: 11/09/2022]
Abstract
The increasing incidence of multidrug resistant uropathogenic E. coli (MDR-UPEC), the most common opportunistic pathogen in urinary tract infections (UTI) pose a global health problem and demands searching for alternative therapeutics. Antibiotics generate oxidative stress in bacteria which results in overexpression of the universal stress protein, UspA that helps in bacterial survival. An in silico study showed that two compounds ZINC000104153710, and ZINC000000217308 effectively bound bacterial UspA. This study aimed to determine the activity of ZINC000104153710, and ZINC000000217308 against bacterial UspA function in MDR-UPEC in vitro. Twenty-five highly MDR-UPEC were screened against ZINC000104153710, and, ZINC000000217308 either alone or in combination with the bactericidal antibiotics; ciprofloxacin (CIP), ceftazidime(CAZ), gentamicin(GEN) respectively by determining minimum inhibitory concentrations (MICs) using a broth microdilution assay. Additionally, the effect of ZINC000104153710, and ZINC000000217308 in the absence and presence of antibiotics on the bacteria was monitored by bacterial growth curve assays, ROS production, structure of the organism by scanning electron microscopy (FESEM) and quantitating UspA using a western blot technique. A 2-8 fold reduction in MIC values against ZINC000104153710, and ZINC000000217308 was observed against all 25 MDR-UPEC isolates in the presence of antibiotics with no alteration in intracellular ROS production. Discrete changes in cell morphology was evident in bacteria treated with ZINC000104153710 or ZINC000000217308 and antibiotics individually by FESEM compared with untreated control. Reduction in the level of UspA protein in bacteria treated with combination of ZINC000104153710 or ZINC000000217308 with individual antibiotics established their ability to inhibit UspA whose expression was elevated in presence of antibiotics alone. Therefore this study validated ZINC000104153710, and ZINC000000217308 as potent inhibitors of bacterial UspA function and indicated their potential as alternative therapeutics to combat the MDR-UPEC.
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Affiliation(s)
- Debojyoty Bandyopadhyay
- Department of Biochemistry and Medical Biotechnology, Calcutta School of Tropical Medicine, Kolkata, West Bengal, India
| | - Mandira Mukherjee
- Department of Biochemistry and Medical Biotechnology, Calcutta School of Tropical Medicine, Kolkata, West Bengal, India.
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Acinetobacter baumannii regulates its stress responses via the BfmRS two-component regulatory system. J Bacteriol 2021; 204:e0049421. [PMID: 34871031 DOI: 10.1128/jb.00494-21] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Acinetobacter baumannii is a common nosocomial pathogen that utilizes numerous mechanisms to aid its survival in both the environment and in the host. Coordination of such mechanisms requires an intricate regulatory network. We report here that A. baumannii can directly regulate several stress-related pathways via the two-component regulatory system, BfmRS. Similar to previous studies, results from transcriptomic analysis showed that mutation of the BfmR response regulator causes dysregulation of genes required for the oxidative stress response, the osmotic stress response, the misfolded protein/heat shock response, Csu pili/fimbriae production, and capsular polysaccharide biosynthesis. We also found that the BfmRS system is involved in controlling siderophore biosynthesis and transport, and type IV pili production. We provide evidence that BfmR binds to various stress-related promoter regions and show that BfmR alone can directly activate transcription of some stress-related genes. Additionally, we show that the BfmS sensor kinase acts as a BfmR phosphatase to negatively regulate BfmR activity. This work highlights the importance of the BfmRS system in promoting survival of A. baumannii. Importance Acinetobacter baumannii is a nosocomial pathogen that has extremely high rates of multidrug resistance. This organism's ability to endure stressful conditions is a key part of its ability to spread in the hospital environment and cause infections. Unlike other members of the γ-proteobacteria, A. baumannii does not encode a homolog of the RpoS sigma factor to coordinate its stress response. Here, we demonstrate that the BfmRS two-component system directly controls the expression of multiple stress resistance genes. Our findings suggest that BfmRS is central to a unique scheme of general stress response regulation by A. baumannii.
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Masamba P, Kappo AP. Parasite Survival and Disease Persistence in Cystic Fibrosis, Schistosomiasis and Pathogenic Bacterial Diseases: A Role for Universal Stress Proteins? Int J Mol Sci 2021; 22:10878. [PMID: 34639223 PMCID: PMC8509486 DOI: 10.3390/ijms221910878] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 09/15/2021] [Accepted: 09/28/2021] [Indexed: 12/16/2022] Open
Abstract
Universal stress proteins (USPs) were originally discovered in Escherichia coli over two decades ago and since then their presence has been detected in various organisms that include plants, archaea, metazoans, and bacteria. As their name suggests, they function in a series of various cellular responses in both abiotic and biotic stressful conditions such as oxidative stress, exposure to DNA damaging agents, nutrient starvation, high temperature and acidic stress, among others. Although a highly conserved group of proteins, the molecular and biochemical aspects of their functions are largely evasive. This is concerning, as it was observed that USPs act as essential contributors to the survival/persistence of various infectious pathogens. Their ubiquitous nature in various organisms, as well as their augmentation during conditions of stress, is a clear indication of their direct or indirect importance in providing resilience against such conditions. This paper seeks to clarify what has already been reported in the literature on the proposed mechanism of action of USPs in pathogenic organisms.
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Affiliation(s)
- Priscilla Masamba
- Molecular Biophysics and Structural Biology (MBSB) Group, Department of Biochemistry, Kingsway Campus, University of Johannesburg, Auckland Park 2006, South Africa;
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20
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Ma C, McClean S. Mapping Global Prevalence of Acinetobacter baumannii and Recent Vaccine Development to Tackle It. Vaccines (Basel) 2021; 9:vaccines9060570. [PMID: 34205838 PMCID: PMC8226933 DOI: 10.3390/vaccines9060570] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 05/16/2021] [Accepted: 05/22/2021] [Indexed: 12/23/2022] Open
Abstract
Acinetobacter baumannii is a leading cause of nosocomial infections that severely threaten public health. The formidable adaptability and resistance of this opportunistic pathogen have hampered the development of antimicrobial therapies which consequently leads to very limited treatment options. We mapped the global prevalence of multidrug-resistant A. baumannii and showed that carbapenem-resistant A. baumannii is widespread throughout Asia and the Americas. Moreover, when antimicrobial resistance rates of Acinetobacter spp. exceed a threshold level, the proportion of A. baumannii isolates from clinical samples surges. Therefore, vaccines represent a realistic alternative strategy to tackle this pathogen. Research into anti-A. baumannii vaccines have enhanced in the past decade and multiple antigens have been investigated preclinically with varying results. This review summarises the current knowledge of virulence factors relating to A. baumannii–host interactions and its implication in vaccine design, with a view to understanding the current state of A. baumannii vaccine development and the direction of future efforts.
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21
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Wang P, Li RQ, Wang L, Yang WT, Zou QH, Xiao D. Proteomic Analyses of Acinetobacter baumannii Clinical Isolates to Identify Drug Resistant Mechanism. Front Cell Infect Microbiol 2021; 11:625430. [PMID: 33718272 PMCID: PMC7943614 DOI: 10.3389/fcimb.2021.625430] [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: 11/03/2020] [Accepted: 01/11/2021] [Indexed: 12/25/2022] Open
Abstract
Acinetobacter baumannii is one of the main causes of nosocomial infections. Increasing numbers of multidrug-resistant Acinetobacter baumannii cases have been reported in recent years, but its antibiotic resistance mechanism remains unclear. We studied 9 multidrug-resistant (MDR) and 10 drug-susceptible Acinetobacter baumannii clinical isolates using Label free, TMT labeling approach and glycoproteomics analysis to identify proteins related to drug resistance. Our results showed that 164 proteins exhibited different expressions between MDR and drug-susceptible isolates. These differential proteins can be classified into six groups: a. proteins related to antibiotic resistance, b. membrane proteins, membrane transporters and proteins related to membrane formation, c. Stress response-related proteins, d. proteins related to gene expression and protein translation, e. metabolism-related proteins, f. proteins with unknown function or other functions containing biofilm formation and virulence. In addition, we verified seven proteins at the transcription level in eight clinical isolates by using quantitative RT-PCR. Results showed that four of the selected proteins have positive correlations with the protein level. This study provided an insight into the mechanism of antibiotic resistance of multidrug-resistant Acinetobacter baumannii.
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Affiliation(s)
- Ping Wang
- Department of Microbiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Ren-Qing Li
- Institute for Control of Infectious Diseases and Endemic Diseases, Beijing Center for Disease Prevention and Control, Beijing, China
| | - Lei Wang
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Wen-Tao Yang
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Qing-Hua Zou
- Department of Microbiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Di Xiao
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
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Kashyap S, Kaur S, Sharma P, Capalash N. Combination of colistin and tobramycin inhibits persistence of Acinetobacter baumannii by membrane hyperpolarization and down-regulation of efflux pumps. Microbes Infect 2021; 23:104795. [PMID: 33567337 DOI: 10.1016/j.micinf.2021.104795] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 01/15/2021] [Accepted: 01/30/2021] [Indexed: 01/03/2023]
Abstract
Acinetobacter baumannii, a leading cause of nosocomial infections, is a serious health threat. Limited therapeutic options due to multi-drug resistance and tolerance due to persister cells have urged the scientific community to develop new strategies to combat infections caused by this pathogen effectively. Since combination antibiotic therapy is an attractive strategy, the effect of combinations of antibiotics, belonging to four classes, was investigated on eradication of persister cells in A. baumannii. Among the antibiotics included in the study, tobramycin-based combinations were found to be the most effective. Tobramycin, in combination with colistin or ciprofloxacin, eradicated persister cells in A. baumannii in late exponential and stationary phases of growth. Mechanistically, colistin facilitated the entry of tobramycin into cells by increasing membrane permeability and inducing hyperpolarization of the inner membrane accompanied by increase in ROS production. Expression of the genes encoding universal stress protein and efflux pumps was down-regulated in response to tobramycin and colistin, suggesting increased lethality of their combination that might be responsible for eradication of persister cells. Thus, a combination of tobramycin and colistin could be explored as a promising option for preventing the relapse of A. baumannii infections due to persister cells.
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Affiliation(s)
- Shruti Kashyap
- Department of Biotechnology, Panjab University, Chandigarh, 160014, India
| | - Sukhvir Kaur
- Department of Biotechnology, Panjab University, Chandigarh, 160014, India
| | - Prince Sharma
- Department of Microbiology, Panjab University, Chandigarh, 160014, India
| | - Neena Capalash
- Department of Biotechnology, Panjab University, Chandigarh, 160014, India.
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23
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Gallagher P, Baker S. Developing new therapeutic approaches for treating infections caused by multi-drug resistant Acinetobacter baumannii. J Infect 2020; 81:857-861. [DOI: 10.1016/j.jinf.2020.10.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 10/21/2020] [Indexed: 12/23/2022]
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Proteomic and Systematic Functional Profiling Unveils Citral Targeting Antibiotic Resistance, Antioxidant Defense, and Biofilm-Associated Two-Component Systems of Acinetobacter baumannii To Encumber Biofilm and Virulence Traits. mSystems 2020; 5:5/6/e00986-20. [PMID: 33203690 PMCID: PMC7677002 DOI: 10.1128/msystems.00986-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Acinetobacter baumannii is a nosocomial-infection-causing bacterium and also possesses multidrug resistance to a wide range of conventional antibiotics. The biofilm-forming ability of A. baumannii plays a major role in its resistance and persistence. There is an alarming need for novel treatment strategies to control A. baumannii biofilm-associated issues. The present study demonstrated the strong antibiofilm and antivirulence efficacy of citral against A. baumannii. In addition, proteomic analysis revealed the multitarget potential of citral against A. baumannii. Furthermore, citral treatment enhances the susceptibility of A. baumannii to the host innate immune system and reactive oxygen species (ROS). Cytotoxicity analysis revealed the nonfatal effect of citral on human PBMCs. Therefore, citral could be the safest therapeutic compound and can be taken for further clinical evaluation for the treatment of biofilm-associated infections by A. baumannii. Acinetobacter baumannii has been reported as a multidrug-resistant bacterium due to biofilms and antimicrobial resistance mechanisms. Hence, novel therapeutic strategies are necessary to overcome A. baumannii infections. This study revealed that citral at 200 μg/ml attenuated A. baumannii biofilms by up to 90% without affecting viability. Furthermore, microscopic analyses and in vitro assays confirmed the antibiofilm efficacy of citral. The global effect of citral on A. baumannii was evaluated by proteomic, transcriptional, and in silico approaches. Two-dimensional (2D) gel electrophoresis and matrix-assisted laser desorption ionization–time of flight/time of flight (MALDI-TOF/TOF) analyses were used to assess the effect of citral on the A. baumannii cellular proteome. Quantitative real-time PCR (qPCR) analysis was done to validate the proteomic data and identify the differentially expressed A. baumannii genes. Protein-protein interactions, gene enrichment, and comparative gene network analyses were performed to explore the interactions and functional attributes of differentially expressed proteins of A. baumannii. Global omics-based analyses revealed that citral targeted various mechanisms such as biofilm formation, antibiotic resistance, antioxidant defense, iron acquisition, and type II and type IV secretion systems. The results of antioxidant analyses and antibiotic sensitivity, blood survival, lipase, and hemolysis assays validated the proteomic results. Cytotoxicity analysis showed a nontoxic effect of citral on peripheral blood mononuclear cells (PBMCs). Overall, the current study unveiled that citral has multitarget efficacy to inhibit the biofilm formation and virulence of A. baumannii. IMPORTANCEAcinetobacter baumannii is a nosocomial-infection-causing bacterium and also possesses multidrug resistance to a wide range of conventional antibiotics. The biofilm-forming ability of A. baumannii plays a major role in its resistance and persistence. There is an alarming need for novel treatment strategies to control A. baumannii biofilm-associated issues. The present study demonstrated the strong antibiofilm and antivirulence efficacy of citral against A. baumannii. In addition, proteomic analysis revealed the multitarget potential of citral against A. baumannii. Furthermore, citral treatment enhances the susceptibility of A. baumannii to the host innate immune system and reactive oxygen species (ROS). Cytotoxicity analysis revealed the nonfatal effect of citral on human PBMCs. Therefore, citral could be the safest therapeutic compound and can be taken for further clinical evaluation for the treatment of biofilm-associated infections by A. baumannii.
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25
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Ng SY, Ong KX, Surendran ST, Sinha A, Lai JJH, Chen J, Liang J, Tay LKS, Cui L, Loo HL, Ho P, Han J, Moreira W. Hydrogen Sulfide Sensitizes Acinetobacter baumannii to Killing by Antibiotics. Front Microbiol 2020; 11:1875. [PMID: 32849459 PMCID: PMC7427342 DOI: 10.3389/fmicb.2020.01875] [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: 05/18/2020] [Accepted: 07/16/2020] [Indexed: 01/25/2023] Open
Abstract
The production of endogenous hydrogen sulfide (H2S) has been shown to confer antibiotic tolerance in all bacteria studied to date. Therefore, this mediator has been speculated to be a universal defense mechanism against antibiotics in bacteria. This is assuming that all bacteria produce endogenous H2S. In this study, we established that the pathogenic bacteria Acinetobacter baumannii does not produce endogenous H2S, giving us the opportunity to test the effect of exogenous H2S on antibiotic tolerance in a bacterium that does not produce it. By using a H2S-releasing compound to modulate the sulfide content in A. baumannii, we demonstrated that instead of conferring antibiotic tolerance, exogenous H2S sensitized A. baumannii to multiple antibiotic classes, and was able to revert acquired resistance to gentamicin. Exogenous H2S triggered a perturbation of redox and energy homeostasis that translated into hypersensitivity to antibiotic killing. We propose that H2S could be used as an antibiotic-potentiator and resistance-reversion agent in bacteria that do not produce it.
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Affiliation(s)
- Say Yong Ng
- Antimicrobial Resistance Interdisciplinary Research Group (AMR IRG), Singapore-MIT Alliance for Research and Technology (SMART) Centre, Singapore, Singapore
| | - Kai Xun Ong
- Antimicrobial Resistance Interdisciplinary Research Group (AMR IRG), Singapore-MIT Alliance for Research and Technology (SMART) Centre, Singapore, Singapore
| | - Smitha Thamarath Surendran
- Antimicrobial Resistance Interdisciplinary Research Group (AMR IRG), Singapore-MIT Alliance for Research and Technology (SMART) Centre, Singapore, Singapore.,Critical Analytics for Manufacturing Personalized-Medicine Interdisciplinary Research Group (CAMP IRG), Singapore-MIT Alliance for Research and Technology (SMART) Centre, Singapore, Singapore
| | - Ameya Sinha
- Antimicrobial Resistance Interdisciplinary Research Group (AMR IRG), Singapore-MIT Alliance for Research and Technology (SMART) Centre, Singapore, Singapore.,Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States.,School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Joey Jia Hui Lai
- Antimicrobial Resistance Interdisciplinary Research Group (AMR IRG), Singapore-MIT Alliance for Research and Technology (SMART) Centre, Singapore, Singapore
| | - Jacqueline Chen
- Antimicrobial Resistance Interdisciplinary Research Group (AMR IRG), Singapore-MIT Alliance for Research and Technology (SMART) Centre, Singapore, Singapore
| | - Jiaqi Liang
- Antimicrobial Resistance Interdisciplinary Research Group (AMR IRG), Singapore-MIT Alliance for Research and Technology (SMART) Centre, Singapore, Singapore.,School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Leona Kwan Sing Tay
- Antimicrobial Resistance Interdisciplinary Research Group (AMR IRG), Singapore-MIT Alliance for Research and Technology (SMART) Centre, Singapore, Singapore
| | - Liang Cui
- Antimicrobial Resistance Interdisciplinary Research Group (AMR IRG), Singapore-MIT Alliance for Research and Technology (SMART) Centre, Singapore, Singapore
| | - Hooi Linn Loo
- Antimicrobial Resistance Interdisciplinary Research Group (AMR IRG), Singapore-MIT Alliance for Research and Technology (SMART) Centre, Singapore, Singapore
| | - Peiying Ho
- Antimicrobial Resistance Interdisciplinary Research Group (AMR IRG), Singapore-MIT Alliance for Research and Technology (SMART) Centre, Singapore, Singapore
| | - Jongyoon Han
- Antimicrobial Resistance Interdisciplinary Research Group (AMR IRG), Singapore-MIT Alliance for Research and Technology (SMART) Centre, Singapore, Singapore.,Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States.,Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Wilfried Moreira
- Antimicrobial Resistance Interdisciplinary Research Group (AMR IRG), Singapore-MIT Alliance for Research and Technology (SMART) Centre, Singapore, Singapore
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26
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Walsh BJC, Wang J, Edmonds KA, Palmer LD, Zhang Y, Trinidad JC, Skaar EP, Giedroc DP. The Response of Acinetobacter baumannii to Hydrogen Sulfide Reveals Two Independent Persulfide-Sensing Systems and a Connection to Biofilm Regulation. mBio 2020; 11:e01254-20. [PMID: 32576676 PMCID: PMC7315123 DOI: 10.1128/mbio.01254-20] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 05/19/2020] [Indexed: 12/13/2022] Open
Abstract
Acinetobacter baumannii is an opportunistic nosocomial pathogen that is the causative agent of several serious infections in humans, including pneumonia, sepsis, and wound and burn infections. A. baumannii is also capable of forming proteinaceous biofilms on both abiotic and epithelial cell surfaces. Here, we investigate the response of A. baumannii toward sodium sulfide (Na2S), known to be associated with some biofilms at oxic/anoxic interfaces. The addition of exogenous inorganic sulfide reveals that A. baumannii encodes two persulfide-sensing transcriptional regulators, a primary σ54-dependent transcriptional activator (FisR), and a secondary system controlled by the persulfide-sensing biofilm growth-associated repressor (BigR), which is only induced by sulfide in a fisR deletion strain. FisR activates an operon encoding a sulfide oxidation/detoxification system similar to that characterized previously in Staphylococcus aureus, while BigR regulates a secondary persulfide dioxygenase (PDO2) as part of yeeE-yedE-pdo2 sulfur detoxification operon, found previously in Serratia spp. Global S-sulfuration (persulfidation) mapping of the soluble proteome reveals 513 persulfidation targets well beyond FisR-regulated genes and includes five transcriptional regulators, most notably the master biofilm regulator BfmR and a poorly characterized catabolite regulatory protein (Crp). Both BfmR and Crp are well known to impact biofilm formation in A. baumannii and other organisms, respectively, suggesting that persulfidation of these regulators may control their activities. The implications of these findings on bacterial sulfide homeostasis, persulfide signaling, and biofilm formation are discussed.IMPORTANCE Although hydrogen sulfide (H2S) has long been known as a respiratory poison, recent reports in numerous bacterial pathogens reveal that H2S and more downstream oxidized forms of sulfur collectedly termed reactive sulfur species (RSS) function as antioxidants to combat host efforts to clear the infection. Here, we present a comprehensive analysis of the transcriptional and proteomic response of A. baumannii to exogenous sulfide as a model for how this important human pathogen manages sulfide/RSS homeostasis. We show that A. baumannii is unique in that it encodes two independent persulfide sensing and detoxification pathways that govern the speciation of bioactive sulfur in cells. The secondary persulfide sensor, BigR, impacts the expression of biofilm-associated genes; in addition, we identify two other transcriptional regulators known or projected to regulate biofilm formation, BfmR and Crp, as highly persulfidated in sulfide-exposed cells. These findings significantly strengthen the connection between sulfide homeostasis and biofilm formation in an important human pathogen.
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Affiliation(s)
- Brenna J C Walsh
- Department of Chemistry, Indiana University, Bloomington, Indiana, USA
| | - Jiefei Wang
- Department of Chemistry, Indiana University, Bloomington, Indiana, USA
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana, USA
| | | | - Lauren D Palmer
- Department of Pathology, Microbiology and Immunology, and Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Yixiang Zhang
- Laboratory for Biological Mass Spectrometry, Indiana University, Bloomington, Indiana, USA
| | - Jonathan C Trinidad
- Laboratory for Biological Mass Spectrometry, Indiana University, Bloomington, Indiana, USA
| | - Eric P Skaar
- Department of Pathology, Microbiology and Immunology, and Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - David P Giedroc
- Department of Chemistry, Indiana University, Bloomington, Indiana, USA
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana, USA
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27
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Fang QJ, Han YX, Shi YJ, Huang HQ, Fang ZG, Hu YH. Universal stress proteins contribute Edwardsiella piscicida adversity resistance and pathogenicity and promote blocking host immune response. FISH & SHELLFISH IMMUNOLOGY 2019; 95:248-258. [PMID: 31654767 DOI: 10.1016/j.fsi.2019.10.035] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 10/02/2019] [Accepted: 10/19/2019] [Indexed: 06/10/2023]
Abstract
Universal stress proteins (Usps) exist ubiquitously in bacteria and other organisms. Usps play an important role in adaptation of bacteria to a variety of environmental stresses. There is increasing evidence that Usps facilitate pathogens to adapt host environment and are involved in pathogenicity. Edwardsiella piscicida (formerly included in E. tarda) is a severe fish pathogen and infects various important economic fish including tilapia (Oreochromis niloticus). In E. piscicida, a number of systems and factors that are involved in stress resistance and pathogenesis were identified. However, the function of Usps in E. piscicida is totally unknown. In this study, we examined the expressions of 13 usp genes in E. piscicida and found that most of these usp genes were up-regulated expression under high temperature, oxidative stress, acid stress, and host serum stress. Particularly, among these usp genes, usp13, exhibited dramatically high expression level upon several stress conditions. To investigate the biological role of usp13, a markerless usp13 in-frame mutant strain, TX01Δusp13, was constructed. Compared to the wild type TX01, TX01Δusp13 exhibited markedly compromised tolerance to high temperature, hydrogen peroxide, and low pH. Deletion of usp13 significantly retarded bacterial biofilm growth and decreased resistance against serum killing. Pathogenicity analysis showed that the inactivation of usp13 significantly impaired the ability of E. piscicida to invade into host cell and infect host tissue. Introduction of a trans-expressed usp13 gene restored the lost virulence of TX01Δusp13. In support of these results, host immune response induced by TX01 and TX01Δusp13 was examined, and the results showed reactive oxygen species (ROS) levels in TX01Δusp13-infected macrophages were significantly higher than those in TX01-infected cells. The expression level of several cytokines (IL-6, IL-8, IL-10, TNF-α, and CC2) in TX01Δusp13-infected fish was significantly higher than that in TX01-infected fish. These results suggested that the deletion of usp13 attenuated the ability of bacteria to overcome the host immune response to pathogen infection. Taken together, our study indicated Usp13 of E. piscicida was not only important participant in adversity resistance, but also was essential for E. piscicida pathogenicity and contributed to block host immune response to pathogen infection.
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Affiliation(s)
- Qing-Jian Fang
- Key Laboratory of Tropical Biological Resources of Ministry of Education, College of Marine Science, Hainan University, Haikou, 570228, China; Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, China
| | - Yue-Xin Han
- Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, China
| | - Yan-Jie Shi
- Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, China
| | - Hui-Qin Huang
- Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, China; Hainan Provincial Key Laboratory for Functional Components Research and Utilization of Marine Bio-resources, Haikou, 571101, China
| | - Zai-Guang Fang
- Key Laboratory of Tropical Biological Resources of Ministry of Education, College of Marine Science, Hainan University, Haikou, 570228, China.
| | - Yong-Hua Hu
- Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, China; Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology (Qingdao), China; Hainan Provincial Key Laboratory for Functional Components Research and Utilization of Marine Bio-resources, Haikou, 571101, China.
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Multidrug-resistant Acinetobacter baumannii resists reactive oxygen species and survives in macrophages. Sci Rep 2019; 9:17462. [PMID: 31767923 PMCID: PMC6877552 DOI: 10.1038/s41598-019-53846-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 11/06/2019] [Indexed: 01/27/2023] Open
Abstract
We investigated the intracellular survival of multidrug-resistant Acinetobacter baumannii (MDRAB) clinical isolates in macrophages, after phagocytosis, to determine their virulence characteristics. After ATCC 19606 and 5 clinical isolates of MDRAB were phagocytosed by mouse and human macrophages, the bacterial count of MDRAB strains, R4 and R5, increased in the mouse macrophages, 24 hours after phagocytosis. Bacterial count of the strains, R1 and R2, was almost equal 4 and 24 hours after phagocytosis. Intracellular reactive oxygen species was detected in the macrophages after phagocytosis of these bacteria. Further, the strains R1, R2, R4, and R5 showed higher catalase activity than ATCC 19606. Additionally, strains R1, R4, and R5 grew more efficiently than ATCC 19606 in the presence of H2O2, whereas growth of strains R2 and R3 was marginally more than that of ATCC 19606 in the presence of H2O2. The MDRAB clinical isolates altered the expression of TNF-α, IL-1β, IL-6, and MIP-2 mRNA induced in J774A.1 cells, 24 hours after phagocytosis. These results provide insights into the renewed virulence characteristics of MDRAB clinical isolates. Finally, tigecycline killed MDRAB phagocytosed by the macrophages more effectively than colistin, although colistin and tigecycline are both considered effective antibiotics for the treatment of MDRAB.
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29
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Toll-Like Receptors 2 and 4 Modulate Pulmonary Inflammation and Host Factors Mediated by Outer Membrane Vesicles Derived from Acinetobacter baumannii. Infect Immun 2019; 87:IAI.00243-19. [PMID: 31262980 DOI: 10.1128/iai.00243-19] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 06/11/2019] [Indexed: 11/20/2022] Open
Abstract
Pneumonia due to Gram-negative bacteria is associated with high mortality. Acinetobacter baumannii is a Gram-negative bacterium that is associated with hospital-acquired and ventilator-associated pneumonia. Bacteria have been described to release outer membrane vesicles (OMVs) that are capable of mediating systemic inflammation. The mechanism by which A. baumannii OMVs mediate inflammation is not fully defined. We sought to investigate the roles that Toll-like receptors (TLRs) play in A. baumannii OMV-mediated pulmonary inflammation. We isolated OMVs from A. baumannii cultures and intranasally introduced the OMVs into mice. Intranasal introduction of A. baumannii OMVs mediated pulmonary inflammation, which is associated with neutrophil recruitment and weight loss. In addition, A. baumannii OMVs increased the release of several chemokines and cytokines in the mouse lungs. The proinflammatory responses were partially inhibited in TLR2- and TLR4-deficient mice compared to those of wild-type mice. This study highlights the important roles of TLRs in A. baumannii OMV-induced pulmonary inflammation in vivo.
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30
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Morris FC, Dexter C, Kostoulias X, Uddin MI, Peleg AY. The Mechanisms of Disease Caused by Acinetobacter baumannii. Front Microbiol 2019; 10:1601. [PMID: 31379771 PMCID: PMC6650576 DOI: 10.3389/fmicb.2019.01601] [Citation(s) in RCA: 158] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 06/26/2019] [Indexed: 01/29/2023] Open
Abstract
Acinetobacter baumannii is a Gram negative opportunistic pathogen that has demonstrated a significant insurgence in the prevalence of infections over recent decades. With only a limited number of “traditional” virulence factors, the mechanisms underlying the success of this pathogen remain of great interest. Major advances have been made in the tools, reagents, and models to study A. baumannii pathogenesis, and this has resulted in a substantial increase in knowledge. This article provides a comprehensive review of the bacterial virulence factors, the host immune responses, and animal models applicable for the study of this important human pathogen. Collating the most recent evidence characterizing bacterial virulence factors, their cellular targets and genetic regulation, we have encompassed numerous aspects important to the success of this pathogen, including membrane proteins and cell surface adaptations promoting immune evasion, mechanisms for nutrient acquisition and community interactions. The role of innate and adaptive immune responses is reviewed and areas of paucity in our understanding are highlighted. Finally, with the vast expansion of available animal models over recent years, we have evaluated those suitable for use in the study of Acinetobacter disease, discussing their advantages and limitations.
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Affiliation(s)
- Faye C Morris
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Carina Dexter
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Xenia Kostoulias
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Muhammad Ikhtear Uddin
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Anton Y Peleg
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia.,Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, VIC, Australia
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31
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Zeidler S, Müller V. Coping with low water activities and osmotic stress in Acinetobacter baumannii: significance, current status and perspectives. Environ Microbiol 2019; 21:2212-2230. [PMID: 30773801 DOI: 10.1111/1462-2920.14565] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 02/11/2019] [Accepted: 02/13/2019] [Indexed: 01/26/2023]
Abstract
Multidrug resistant (MDR) pathogens are one of the most pressing challenges of contemporary health care. Acinetobacter baumannii takes a predominant position, emphasized in 2017 by the World Health Organization. The increasing emergence of MDR strains strengthens the demand for new antimicrobials. Possible targets for such compounds might be proteins involved in resistance against low water activity environments, since A. baumannii is known for its pronounced resistance against desiccation stress. Despite the importance of desiccation resistance for persistence of this pathogen in hospitals, comparable studies and precise data on this topic are rare and the mechanisms involved are largely unknown. This review aims to give an overview of the studies performed so far and the current knowledge on genes and proteins important for desiccation survival. 'Osmotic stress' is not identical to 'desiccation stress', but the two share the response of bacteria to low water activities. Osmotic stress resistance is in general studied much better, and in recent years it turned out that accumulation of compatible solutes in A. baumannii comprises some special features such as the bifunctional enzyme MtlD synthesizing the unusual solute mannitol. Furthermore, the regulatory pathways, as understood today, will be discussed.
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Affiliation(s)
- Sabine Zeidler
- Department of Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Goethe-University Frankfurt am Main, Frankfurt am Main, Germany
| | - Volker Müller
- Department of Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Goethe-University Frankfurt am Main, Frankfurt am Main, Germany
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32
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Kalindamar S, Lu J, Abdelhamed H, Tekedar HC, Lawrence ML, Karsi A. Transposon mutagenesis and identification of mutated genes in growth-delayed Edwardsiella ictaluri. BMC Microbiol 2019; 19:55. [PMID: 30849940 PMCID: PMC6408766 DOI: 10.1186/s12866-019-1429-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 02/27/2019] [Indexed: 01/23/2023] Open
Abstract
Background Edwardsiella ictaluri is a Gram-negative facultative intracellular anaerobe and the etiologic agent of enteric septicemia of channel catfish (ESC). To the catfish industry, ESC is a devastating disease due to production losses and treatment costs. Identification of virulence mechanisms of E. ictaluri is critical to developing novel therapeutic approaches for the disease. Here, we report construction of a transposon insertion library and identification of mutated genes in growth-delayed E. ictaluri colonies. We also provide safety and efficacy of transposon insertion mutants in catfish. Results An E. ictaluri transposon insertion library with 45,000 transposants and saturating 30.92% of the TA locations present in the E. ictaluri genome was constructed. Transposon end mapping of 250 growth-delayed E. ictaluri colonies and bioinformatic analysis of sequences revealed 56 unique E. ictaluri genes interrupted by the MAR2xT7 transposon, which are involved in metabolic and cellular processes and mostly localized in the cytoplasm or cytoplasmic membrane. Of the 56 genes, 30 were associated with bacterial virulence. Safety and vaccine efficacy testing of 19 mutants showed that mutants containing transposon insertions in hypothetical protein (Eis::004), and Fe-S cluster assembly protein (IscX, Eis::039), sulfurtransferase (TusA, Eis::158), and universal stress protein A (UspA, Eis::194) were safe and provided significant protection (p < 0.05) against wild-type E. ictaluri. Conclusions The results indicate that random transposon mutagenesis causing growth-delayed phenotype results in identification bacterial virulence genes, and attenuated strains with transposon interrupted virulence genes could be used as vaccine to activate fish immune system.
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Affiliation(s)
- Safak Kalindamar
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA
| | - Jingjun Lu
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA
| | - Hossam Abdelhamed
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA
| | - Hasan C Tekedar
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA
| | - Mark L Lawrence
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA
| | - Attila Karsi
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA.
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Chi YH, Koo SS, Oh HT, Lee ES, Park JH, Phan KAT, Wi SD, Bae SB, Paeng SK, Chae HB, Kang CH, Kim MG, Kim WY, Yun DJ, Lee SY. The Physiological Functions of Universal Stress Proteins and Their Molecular Mechanism to Protect Plants From Environmental Stresses. FRONTIERS IN PLANT SCIENCE 2019; 10:750. [PMID: 31231414 PMCID: PMC6560075 DOI: 10.3389/fpls.2019.00750] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 05/22/2019] [Indexed: 05/13/2023]
Abstract
Since the original discovery of a Universal Stress Protein (USP) in Escherichia coli, a number of USPs have been identified from diverse sources including archaea, bacteria, plants, and metazoans. As their name implies, these proteins participate in a broad range of cellular responses to biotic and abiotic stresses. Their physiological functions are associated with ion scavenging, hypoxia responses, cellular mobility, and regulation of cell growth and development. Consistent with their roles in resistance to multiple stresses, USPs show a wide range of structural diversity that results from the diverse range of other functional motifs fused with the USP domain. As well as providing structural diversity, these catalytic motifs are responsible for the diverse biochemical properties of USPs and enable them to act in a number of cellular signaling transducers and metabolic regulators. Despite the importance of USP function in many organisms, the molecular mechanisms by which USPs protect cells and provide stress resistance remain largely unknown. This review addresses the diverse roles of USPs in plants and how the proteins enable plants to resist against multiple stresses in ever-changing environment. Bioinformatic tools used for the collection of a set of USPs from various plant species provide more than 2,100 USPs and their functional diversity in plant physiology. Data from previous studies are used to understand how the biochemical activity of plant USPs modulates biotic and abiotic stress signaling. As USPs interact with the redox protein, thioredoxin, in Arabidopsis and reactive oxygen species (ROS) regulates the activity of USPs, the involvement of USPs in redox-mediated defense signaling is also considered. Finally, this review discusses the biotechnological application of USPs in an agricultural context by considering the development of novel stress-resistant crops through manipulating the expression of USP genes.
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Affiliation(s)
- Yong Hun Chi
- Division of Applied Life Science (BK21Plus), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, South Korea
| | - Sung Sun Koo
- Division of Applied Life Science (BK21Plus), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, South Korea
| | - Hun Taek Oh
- Division of Applied Life Science (BK21Plus), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, South Korea
| | - Eun Seon Lee
- Division of Applied Life Science (BK21Plus), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, South Korea
| | - Joung Hun Park
- Division of Applied Life Science (BK21Plus), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, South Korea
| | - Kieu Anh Thi Phan
- Division of Applied Life Science (BK21Plus), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, South Korea
| | - Seong Dong Wi
- Division of Applied Life Science (BK21Plus), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, South Korea
| | - Su Bin Bae
- Division of Applied Life Science (BK21Plus), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, South Korea
| | - Seol Ki Paeng
- Division of Applied Life Science (BK21Plus), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, South Korea
| | - Ho Byoung Chae
- Division of Applied Life Science (BK21Plus), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, South Korea
| | - Chang Ho Kang
- Division of Applied Life Science (BK21Plus), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, South Korea
| | - Min Gab Kim
- College of Pharmacy and Research Institute of Pharmaceutical Science, Gyeongsang National University, Jinju, South Korea
| | - Woe-Yeon Kim
- Division of Applied Life Science (BK21Plus), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, South Korea
- Institute of Agricultural and Life Science (IALS), Gyeongsang National University, Jinju, South Korea
| | - Dae-Jin Yun
- Department of Biomedical Science and Engineering, Konkuk University, Seoul, South Korea
| | - Sang Yeol Lee
- Division of Applied Life Science (BK21Plus), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, South Korea
- *Correspondence: Sang Yeol Lee,
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Juttukonda LJ, Green ER, Lonergan ZR, Heffern MC, Chang CJ, Skaar EP. Acinetobacter baumannii OxyR Regulates the Transcriptional Response to Hydrogen Peroxide. Infect Immun 2019; 87:e00413-18. [PMID: 30297527 PMCID: PMC6300632 DOI: 10.1128/iai.00413-18] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 10/03/2018] [Indexed: 12/21/2022] Open
Abstract
Acinetobacter baumannii is a Gram-negative opportunistic pathogen that causes diverse infections, including pneumonia, bacteremia, and wound infections. Due to multiple intrinsic and acquired antimicrobial-resistance mechanisms, A. baumannii isolates are commonly multidrug resistant, and infections are notoriously difficult to treat. The World Health Organization recently highlighted carbapenem-resistant A. baumannii as a "critical priority" for the development of new antimicrobials because of the risk to human health posed by this organism. Therefore, it is important to discover the mechanisms used by A. baumannii to survive stresses encountered during infection in order to identify new drug targets. In this study, by use of in vivo imaging, we identified hydrogen peroxide (H2O2) as a stressor produced in the lung during A. baumannii infection and defined OxyR as a transcriptional regulator of the H2O2 stress response. Upon exposure to H2O2, A. baumannii differentially transcribes several hundred genes. However, the transcriptional upregulation of genes predicted to detoxify hydrogen peroxide is abolished in an A. baumannii strain in which the transcriptional regulator oxyR is genetically inactivated. Moreover, inactivation of oxyR in both antimicrobial-susceptible and multidrug-resistant A. baumannii strains impairs growth in the presence of H2O2 OxyR is a direct regulator of katE and ahpF1, which encode the major H2O2-degrading enzymes in A. baumannii, as confirmed through measurement of promoter binding by recombinant OxyR in electromobility shift assays. Finally, an oxyR mutant is less fit than wild-type A. baumannii during infection of the murine lung. This work reveals a mechanism used by this important human pathogen to survive H2O2 stress encountered during infection.
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Affiliation(s)
- Lillian J Juttukonda
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Erin R Green
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Zachery R Lonergan
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Marie C Heffern
- Department of Chemistry, University of California, Berkeley, California, USA
| | - Christopher J Chang
- Department of Chemistry, University of California, Berkeley, California, USA
- Department of Molecular and Cell Biology, University of California, Berkeley, California, USA
- Howard Hughes Medical Institute, University of California, Berkeley, California, USA
| | - Eric P Skaar
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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Akgul A, Nho SW, Kalindamar S, Tekedar HC, Abdalhamed H, Lawrence ML, Karsi A. Universal Stress Proteins Contribute Edwardsiella ictaluri Virulence in Catfish. Front Microbiol 2018; 9:2931. [PMID: 30546354 PMCID: PMC6279896 DOI: 10.3389/fmicb.2018.02931] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 11/14/2018] [Indexed: 11/21/2022] Open
Abstract
Edwardsiella ictaluri is an intracellular Gram-negative facultative pathogen causing enteric septicemia of catfish (ESC), a common disease resulting in substantial economic losses in the U.S. catfish industry. Previously, we demonstrated that several universal stress proteins (USPs) are highly expressed under in vitro and in vivo stress conditions, indicating their importance for E. ictaluri survival. However, the roles of these USPs in E. ictaluri virulence is not known yet. In this work, 10 usp genes of E. ictaluri were in-frame deleted and characterized in vitro and in vivo. Results show that all USP mutants were sensitive to acidic condition (pH 5.5), and EiΔusp05 and EiΔusp08 were very sensitive to oxidative stress (0.1% H2O2). Virulence studies indicated that EiΔusp05, EiΔusp07, EiΔusp08, EiΔusp09, EiΔusp10, and EiΔusp13 were attenuated significantly compared to E. ictaluri wild-type (EiWT; 20, 45, 20, 20, 55, and 10% vs. 74.1% mortality, respectively). Efficacy experiments showed that vaccination of catfish fingerlings with EiΔusp05, EiΔusp07, EiΔusp08, EiΔusp09, EiΔusp10, and EiΔusp13 provided complete protection against EiWT compared to sham-vaccinated fish (0% vs. 58.33% mortality). Our results support that USPs contribute E. ictaluri virulence in catfish.
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Affiliation(s)
- Ali Akgul
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States
| | - Seong Won Nho
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States
| | - Safak Kalindamar
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States
| | - Hasan C Tekedar
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States
| | - Hossam Abdalhamed
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States
| | - Mark L Lawrence
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States
| | - Attila Karsi
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States
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Akgul A, Akgul A, Lawrence ML, Karsi A. Stress-related genes promote Edwardsiella ictaluri pathogenesis. PLoS One 2018; 13:e0194669. [PMID: 29554143 PMCID: PMC5858854 DOI: 10.1371/journal.pone.0194669] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 03/07/2018] [Indexed: 12/22/2022] Open
Abstract
Edwardsiella ictaluri is a Gram-negative facultative anaerobic rod and the causative agent of enteric septicemia of channel catfish (ESC), which is one of the most prevalent diseases of catfish, causing significant economic losses in the catfish industry. E. ictaluri is resistant to complement system and macrophage killing, which results in rapid systemic septicemia. However, mechanisms of E. ictaluri stress responses under conditions of host environment are not studied well. Therefore, in this work, we report E. ictaluri stress responses during hydrogen peroxide, low pH, and catfish serum stresses as well as during catfish invasion. E. ictaluri stress responses were characterized by identifying expression of 13 universal stress protein (USP) genes (usp01-usp13) and seven USP-interacting protein genes (groEL, groES, dnaK, grpE, and clpB, grpE, relA). Data indicated that three usp genes (usp05, usp07, and usp13) were highly expressed in all stress conditions. Similarly, E. ictaluri heat shock proteins groEL, groES, dnaK, grpE, and clpB were highly expressed in oxidative stress. Also, E. ictaluri grpE and relA were highly expressed in catfish spleen and head kidney. These findings contribute to our understanding of stress response mechanisms in E. ictaluri stress response, and stress-related proteins that are essential for E. ictaluri could be potential targets for live attenuated vaccine development against ESC.
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Affiliation(s)
- Ali Akgul
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, United States of America
| | - Ayfer Akgul
- Department of Clinical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, United States of America
| | - Mark L. Lawrence
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, United States of America
| | - Attila Karsi
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, United States of America
- * E-mail:
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Zachow C, Müller H, Laireiter CM, Tilcher R, Berg G. Complete genome sequence of Pseudomonas corrugata strain RM1-1-4, a stress protecting agent from the rhizosphere of an oilseed rape bait plant. Stand Genomic Sci 2017; 12:66. [PMID: 29152037 PMCID: PMC5679145 DOI: 10.1186/s40793-017-0278-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 10/24/2017] [Indexed: 11/10/2022] Open
Abstract
10.1601/nm.2592 strain RM1-1-4 is a rhizosphere colonizer of oilseed rape. A previous study has shown that this motile, Gram-negative, non-sporulating bacterium is an effective stress protecting and biocontrol agent, which protects their hosts against abiotic and biotic stresses. Here, we announce and describe the complete genome sequence of P. corrugata RM1-1-4 consisting of a single 6.1 Mb circular chromosome that encodes 5189 protein coding genes and 85 RNA-only encoding genes. Genome analysis revealed genes predicting functions such as detoxifying mechanisms, stress inhibitors, exoproteases, lipoproteins or volatile components as well as rhizobactin siderophores and spermidine. Further analysis of its genome will help to identify traits promising for stress protection, biocontrol and plant growth promotion properties.
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Affiliation(s)
- Christin Zachow
- Austrian Centre of Industrial Biotechnology (ACIB GmbH), Petersgasse 14, 8010 Graz, Austria
| | - Henry Müller
- Institute of Environmental Biotechnology, Graz University of Technology, Petersgasse 12, 8010 Graz, Austria
| | - Christina M Laireiter
- Austrian Centre of Industrial Biotechnology (ACIB GmbH), Petersgasse 14, 8010 Graz, Austria.,Institute of Environmental Biotechnology, Graz University of Technology, Petersgasse 12, 8010 Graz, Austria
| | - Ralf Tilcher
- KWS SAAT SE, Grimsehlstraße 31, 37555 Einbeck, Germany
| | - Gabriele Berg
- Institute of Environmental Biotechnology, Graz University of Technology, Petersgasse 12, 8010 Graz, Austria
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Vollmer AC, Bark SJ. Twenty-Five Years of Investigating the Universal Stress Protein: Function, Structure, and Applications. ADVANCES IN APPLIED MICROBIOLOGY 2017; 102:1-36. [PMID: 29680123 DOI: 10.1016/bs.aambs.2017.10.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Since the initial discovery of universal stress protein A (UspA) 25 years ago, remarkable advances in molecular and biochemical technologies have revolutionized our understanding of biology. Many studies using these technologies have focused on characterization of the uspA gene and Usp-type proteins. These studies have identified the conservation of Usp-like proteins across bacteria, archaea, plants, and even some invertebrate animals. Regulation of these proteins under diverse stresses has been associated with different stress-response genes including spoT and relA in the stringent response and the dosR two-component signaling pathways. These and other foundational studies suggest Usps serve regulatory and protective roles to enable adaptation and survival under external stresses. Despite these foundational studies, many bacterial species have multiple paralogs of genes encoding these proteins and ablation of the genes does not provide a distinct phenotype. This outcome has limited our understanding of the biochemical functions of these proteins. Here, we summarize the current knowledge of Usps in general and UspA in particular across different genera as well as conclusions about their functions from seminal studies in diverse organisms. Our objective has been to organize the foundational studies in this field to identify the significant impediments to further understanding of Usp functions at the molecular level. We propose ideas and experimental approaches that may overcome these impediments and drive future development of molecular approaches to understand and target Usps as central regulators of stress adaptation and survival. Despite the fact that the full functions of Usps are still not known, creative many applications have already been proposed, tested, and used. The complementary approaches of basic research and applications, along with new technology and analytic tools, may yield the elusive yet critical functions of universal stress proteins in diverse systems.
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Kuo HY, Chao HH, Liao PC, Hsu L, Chang KC, Tung CH, Chen CH, Liou ML. Functional Characterization of Acinetobacter baumannii Lacking the RNA Chaperone Hfq. Front Microbiol 2017; 8:2068. [PMID: 29163381 PMCID: PMC5663733 DOI: 10.3389/fmicb.2017.02068] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 10/09/2017] [Indexed: 12/15/2022] Open
Abstract
The RNA chaperone Hfq is involved in the riboregulation of diverse genes via small RNAs. Recent studies have demonstrated that Hfq contributes to the stress response and the virulence of several pathogens, and the roles of Hfq vary among bacterial species. Here, we attempted to elucidate the role of Hfq in Acinetobacter baumannii ATCC 17978. In the absence of hfq, A. baumannii exhibited retarded cell growth and was highly sensitive to environmental stress, including osmotic and oxidative pressure, pH, and temperature. Compared to the wild-type, the Hfq mutant had reduced outer membrane vesicles secretion and fimbriae production as visualized by atomic force microscopy. The absence of hfq reduced biofilm formation, airway epithelial cell adhesion and invasion, and survival in macrophage. Further, the hfq mutant induced significantly higher IL-8 levels in airway epithelial cells, which would promote bacterial clearance by the host. In addition to results similar to those reported for other bacteria, our findings demonstrate that Hfq is required in the regulation of the iron-acquisition system via downregulating the bauA and basD genes, the stress-related outer membrane proteins carO, A1S_0820, ompA, and nlpE, and the stress-related cytosolic proteins uspA and groEL. Our data indicate that Hfq plays a critical role in environmental adaptation and virulence in A. baumannii by modulating stress responses, surface architectures, and virulence factors. This study is the first to illustrate the functional role of Hfq in A. baumannii.
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Affiliation(s)
- Han-Yueh Kuo
- Department of Medicine, National Taiwan University Hospital Hsin-Chu Branch, Hsinchu, Taiwan.,Department of Internal Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Hsuan-Hao Chao
- Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan
| | - Po-Cheng Liao
- Department of Medical Laboratory Science and Biotechnology, Yuanpei University, Hsinchu, Taiwan
| | - Long Hsu
- Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan
| | - Kai-Chih Chang
- Department of Laboratory Medicine and Biotechnology, Tzu Chi University, Hualien, Taiwan
| | - Chi-Hua Tung
- Department of Bioinformatics, Chung Hua University, Hsinchu, Taiwan
| | - Chang-Hua Chen
- Division of Infectious Disease, Department of Internal Medicine, Changhua Christian Hospital, Changhua, Taiwan.,Center of Infection Prevention and Control, Changhua Christian Hospital, Changhua, Taiwan
| | - Ming-Li Liou
- Department of Medical Laboratory Science and Biotechnology, Yuanpei University, Hsinchu, Taiwan
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40
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Future Directions and Molecular Basis of Ventilator Associated Pneumonia. Can Respir J 2017; 2017:2614602. [PMID: 29162982 PMCID: PMC5661065 DOI: 10.1155/2017/2614602] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 09/14/2017] [Indexed: 12/26/2022] Open
Abstract
Mechanical ventilation is a lifesaving treatment and has complications such as ventilator associated pneumonia (VAP) that lead to high morbidity and mortality. Moreover VAP is the second most common hospital-acquired infection in pediatric intensive care units. Although it is still not well understood, understanding molecular pathogenesis is essential for preventing and treating pneumonia. A lot of microbes are detected as a causative agent of VAP. The most common isolated VAP pathogens in pediatric patients are Staphylococcus aureus, Pseudomonas aeruginosa, and other gram negative bacteria. All of the bacteria have different pathogenesis due to their different virulence factors and host reactions. This review article focused on mechanisms of VAP with molecular pathogenesis of the causative bacteria one by one from the literature. We hope that we know more about molecular pathogenesis of VAP and we can investigate and focus on the management of the disease in near future.
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Clinical and Pathophysiological Overview of Acinetobacter Infections: a Century of Challenges. Clin Microbiol Rev 2017; 30:409-447. [PMID: 27974412 DOI: 10.1128/cmr.00058-16] [Citation(s) in RCA: 642] [Impact Index Per Article: 91.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Acinetobacter is a complex genus, and historically, there has been confusion about the existence of multiple species. The species commonly cause nosocomial infections, predominantly aspiration pneumonia and catheter-associated bacteremia, but can also cause soft tissue and urinary tract infections. Community-acquired infections by Acinetobacter spp. are increasingly reported. Transmission of Acinetobacter and subsequent disease is facilitated by the organism's environmental tenacity, resistance to desiccation, and evasion of host immunity. The virulence properties demonstrated by Acinetobacter spp. primarily stem from evasion of rapid clearance by the innate immune system, effectively enabling high bacterial density that triggers lipopolysaccharide (LPS)-Toll-like receptor 4 (TLR4)-mediated sepsis. Capsular polysaccharide is a critical virulence factor that enables immune evasion, while LPS triggers septic shock. However, the primary driver of clinical outcome is antibiotic resistance. Administration of initially effective therapy is key to improving survival, reducing 30-day mortality threefold. Regrettably, due to the high frequency of this organism having an extreme drug resistance (XDR) phenotype, early initiation of effective therapy is a major clinical challenge. Given its high rate of antibiotic resistance and abysmal outcomes (up to 70% mortality rate from infections caused by XDR strains in some case series), new preventative and therapeutic options for Acinetobacter spp. are desperately needed.
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42
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Murray GL, Tsyganov K, Kostoulias XP, Bulach DM, Powell D, Creek DJ, Boyce JD, Paulsen IT, Peleg AY. Global Gene Expression Profile of Acinetobacter baumannii During Bacteremia. J Infect Dis 2017; 215:S52-S57. [PMID: 28375520 DOI: 10.1093/infdis/jiw529] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Background Acinetobacter baumannii is a pathogen of major importance in intensive care units worldwide, with the potential to cause problematic outbreaks and acquire high-level resistance to antibiotics. There is an urgent need to understand the mechanisms of A. baumannii pathogenesis for the future development of novel targeted therapies. In this study we performed an in vivo transcriptomic analysis of A. baumannii isolated from a mammalian host with bacteremia. Methods Mice were infected with A. baumannii American Type Culture Collection 17978 using an intraperitoneal injection, and blood was extracted at 8 hours to purify bacterial RNA for RNA-Seq with an Illumina platform. Results Approximately one-quarter of A. baumannii protein coding genes were differentially expressed in vivo compared with in vitro (false discovery rate, ≤0.001; 2-fold change) with 557 showing decreased and 329 showing increased expression. Gene groups with functions relating to translation and RNA processing were overrepresented in genes with increased expression, and those relating to chaperone and protein turnover were overrepresented in the genes with decreased expression. The most strongly up-regulated genes corresponded to the 3 recognized siderophore iron uptake clusters, reflecting the iron-restrictive environment in vivo. Metabolic changes in vivo included reduced expression of genes involved in amino acid and fatty acid transport and catabolism, indicating metabolic adaptation to a different nutritional environment. Genes encoding types I and IV pili, quorum sensing components, and proteins involved in biofilm formation all showed reduced expression. Many genes that have been reported as essential for virulence showed reduced or unchanged expression in vivo. Conclusion This study provides the first insight into A. baumannii gene expression profiles during a life-threatening mammalian infection. Analysis of differentially regulated genes highlights numerous potential targets for the design of novel therapeutics.
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Affiliation(s)
- Gerald L Murray
- Royal Women's Hospital.,Murdoch Childrens Research Institute, Parkville, Victoria.,Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology
| | | | - Xenia P Kostoulias
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology
| | | | - David Powell
- Monash Bioinformatics Platform, Monash University, Clayton
| | - Darren J Creek
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville
| | - John D Boyce
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology
| | - Ian T Paulsen
- Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Anton Y Peleg
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology.,Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, Victoria, and
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Lee CR, Lee JH, Park M, Park KS, Bae IK, Kim YB, Cha CJ, Jeong BC, Lee SH. Biology of Acinetobacter baumannii: Pathogenesis, Antibiotic Resistance Mechanisms, and Prospective Treatment Options. Front Cell Infect Microbiol 2017; 7:55. [PMID: 28348979 PMCID: PMC5346588 DOI: 10.3389/fcimb.2017.00055] [Citation(s) in RCA: 510] [Impact Index Per Article: 72.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 02/13/2017] [Indexed: 12/27/2022] Open
Abstract
Acinetobacter baumannii is undoubtedly one of the most successful pathogens responsible for hospital-acquired nosocomial infections in the modern healthcare system. Due to the prevalence of infections and outbreaks caused by multi-drug resistant A. baumannii, few antibiotics are effective for treating infections caused by this pathogen. To overcome this problem, knowledge of the pathogenesis and antibiotic resistance mechanisms of A. baumannii is important. In this review, we summarize current studies on the virulence factors that contribute to A. baumannii pathogenesis, including porins, capsular polysaccharides, lipopolysaccharides, phospholipases, outer membrane vesicles, metal acquisition systems, and protein secretion systems. Mechanisms of antibiotic resistance of this organism, including acquirement of β-lactamases, up-regulation of multidrug efflux pumps, modification of aminoglycosides, permeability defects, and alteration of target sites, are also discussed. Lastly, novel prospective treatment options for infections caused by multi-drug resistant A. baumannii are summarized.
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Affiliation(s)
- Chang-Ro Lee
- National Leading Research Laboratory of Drug Resistance Proteomics, Department of Biological Sciences, Myongji University Yongin, South Korea
| | - Jung Hun Lee
- National Leading Research Laboratory of Drug Resistance Proteomics, Department of Biological Sciences, Myongji University Yongin, South Korea
| | - Moonhee Park
- National Leading Research Laboratory of Drug Resistance Proteomics, Department of Biological Sciences, Myongji UniversityYongin, South Korea; DNA Analysis Division, Seoul Institute, National Forensic ServiceSeoul, South Korea
| | - Kwang Seung Park
- National Leading Research Laboratory of Drug Resistance Proteomics, Department of Biological Sciences, Myongji University Yongin, South Korea
| | - Il Kwon Bae
- Department of Dental Hygiene, College of Health and Welfare, Silla University Busan, South Korea
| | - Young Bae Kim
- Biotechnology Program, North Shore Community College Danvers, MA, USA
| | - Chang-Jun Cha
- Department of Systems Biotechnology, College of Biotechnology and Natural Resources, Chung-Ang University Anseong, South Korea
| | - Byeong Chul Jeong
- National Leading Research Laboratory of Drug Resistance Proteomics, Department of Biological Sciences, Myongji University Yongin, South Korea
| | - Sang Hee Lee
- National Leading Research Laboratory of Drug Resistance Proteomics, Department of Biological Sciences, Myongji University Yongin, South Korea
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44
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Adaptation to Potassium-Limitation Is Essential forAcinetobacter baumanniiPneumonia Pathogenesis. J Infect Dis 2016; 214:2006-2013. [DOI: 10.1093/infdis/jiw476] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 09/27/2016] [Indexed: 01/01/2023] Open
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Elhosseiny NM, El-Tayeb OM, Yassin AS, Lory S, Attia AS. The secretome of Acinetobacter baumannii ATCC 17978 type II secretion system reveals a novel plasmid encoded phospholipase that could be implicated in lung colonization. Int J Med Microbiol 2016; 306:633-641. [PMID: 27713027 DOI: 10.1016/j.ijmm.2016.09.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Revised: 09/24/2016] [Accepted: 09/30/2016] [Indexed: 02/01/2023] Open
Abstract
Acinetobacter baumannii infections are compounded with a striking lack of treatment options. In many Gram-negative bacteria, secreted proteins play an important early role in avoiding host defences. Typically, these proteins are targeted to the external environment or into host cells using dedicated transport systems. Despite the fact that medically relevant species of Acinetobacter possess a type II secretion system (T2SS), only recently, its significance as an important pathway for delivering virulence factors has gained attention. Using in silico analysis to characterize the genetic determinants of the T2SS, which are found clustered in other organisms, in Acinetobacter species, they appear to have a unique genetic organization and are distributed throughout the genome. When compared to other T2SS orthologs, individual components of the T2SS apparatus showed the highest similarity to those of Pseudomonas aeruginosa. A mutant of Acinetobacter baumannii strain ATCC 17978 lacking the secretin component of the T2SS (ΔgspD), together with a trans-complemented mutant, were tested in a series of in vitro and in vivo assays to determine the role of T2SS in pathogenicity. The ΔgspD mutant displayed decreased lipolytic activity, associated with attenuated colonization ability in a murine pneumonia model. These phenotypes are linked to LipAN, a novel plasmid-encoded phospholipase, identified through mass spectroscopy as a T2SS substrate. Recombinant LipAN showed specific phospholipase activity in vitro. Proteomics on the T2-dependent secretome of ATCC 17978 strain revealed its potential dedication to the secretion of a number of lipolytic enzymes, among others which could contribute to its virulence. This study highlights the role of T2SS as an active contributor to the virulence of A. baumannii potentially through secretion of a newly identified phospholipase.
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Affiliation(s)
- Noha M Elhosseiny
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, 11562, Egypt; Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Ossama M El-Tayeb
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, 11562, Egypt
| | - Aymen S Yassin
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, 11562, Egypt
| | - Stephen Lory
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Ahmed S Attia
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, 11562, Egypt.
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de Souza CS, Torres AG, Caravelli A, Silva A, Polatto JM, Piazza RMF. Characterization of the universal stress protein F from atypical enteropathogenic Escherichia coli and its prevalence in Enterobacteriaceae. Protein Sci 2016; 25:2142-2151. [PMID: 27616205 PMCID: PMC5119564 DOI: 10.1002/pro.3038] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 07/25/2016] [Accepted: 09/06/2016] [Indexed: 01/06/2023]
Abstract
Atypical enteropathogenic Escherichia coli (aEPEC) are heterogeneous strains in terms of serotypes, adherence patterns and the presence of novel virulence factors. This heterogeneity is intriguing, promoting studies trying to characterize these novel proteins and to better comprehend this pathotype group. In a previous study analyzing low-molecular mass proteomes of four representative aEPEC strains of three different adhesion phenotypes, we classified proteins according to their annotated function, with most of them being involved in metabolism and transport; while some of them were classified as hypothetical proteins. The majority of the hypothetical proteins were homologue products of genes identified in the genome of enterohemorrhagic E. coli. One of the hypothetical proteins was annotated as Z2335, with orthologue in EPEC, and by bioinformatics analysis, this protein was revealed to be the universal stress protein F (UspF). Thus, herein we successfully obtained a recombinant UspF protein from aEPEC, which is a α/β, ATP-binding protein involved in stress response, with comparable protein production among the four studied strains, but showing noteworthy differences when cultivated in different stress conditions, also present in other enterobacterial species, such as Shigella sonnei and Citrobacter freundii. Furthermore, our results confirm that the Usp protein superfamily encompasses a conserved group of proteins involved in stress resistance in aEPEC and other Enterobacteriaceae.
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Affiliation(s)
| | - Alfredo G Torres
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas
| | | | - Anderson Silva
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, SP, Brazil
| | - Juliana M Polatto
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, SP, Brazil
| | - Roxane M F Piazza
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, SP, Brazil
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Medically Relevant Acinetobacter Species Require a Type II Secretion System and Specific Membrane-Associated Chaperones for the Export of Multiple Substrates and Full Virulence. PLoS Pathog 2016; 12:e1005391. [PMID: 26764912 PMCID: PMC4713064 DOI: 10.1371/journal.ppat.1005391] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 12/18/2015] [Indexed: 01/31/2023] Open
Abstract
Acinetobacter baumannii, A. nosocomialis, and A. pittii have recently emerged as opportunistic human pathogens capable of causing severe human disease; however, the molecular mechanisms employed by Acinetobacter to cause disease remain poorly understood. Many pathogenic members of the genus Acinetobacter contain genes predicted to encode proteins required for the biogenesis of a type II secretion system (T2SS), which have been shown to mediate virulence in many Gram-negative organisms. Here we demonstrate that Acinetobacter nosocomialis strain M2 produces a functional T2SS, which is required for full virulence in both the Galleria mellonella and murine pulmonary infection models. Importantly, this is the first bona fide secretion system shown to be required for virulence in Acinetobacter. Using bioinformatics, proteomics, and mutational analyses, we show that Acinetobacter employs its T2SS to export multiple substrates, including the lipases LipA and LipH as well as the protease CpaA. Furthermore, the Acinetobacter T2SS, which is found scattered amongst five distinct loci, does not contain a dedicated pseudopilin peptidase, but instead relies on the type IV prepilin peptidase, reinforcing the common ancestry of these two systems. Lastly, two of the three secreted proteins characterized in this study require specific chaperones for secretion. These chaperones contain an N-terminal transmembrane domain, are encoded adjacently to their cognate effector, and their disruption abolishes type II secretion of their cognate effector. Bioinformatic analysis identified putative chaperones located adjacent to multiple previously known type II effectors from several Gram-negative bacteria, which suggests that T2SS chaperones constitute a separate class of membrane-associated chaperones mediating type II secretion.
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Biswas I. Genetic tools for manipulating Acinetobacter baumannii genome: an overview. J Med Microbiol 2015; 64:657-669. [PMID: 25948809 DOI: 10.1099/jmm.0.000081] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Acinetobacter baumannii is an emerging nosocomial pathogen involved in a variety of infections ranging from minor soft-tissue infections to more severe infections such as ventilator-associated pneumonia and bacteraemia. A. baumannii has become resistant to most of the commonly used antibiotics and multidrug-resistant isolates are becoming a severe problem in the healthcare setting. In the past few years, whole-genome sequences of >200 A. baumannii isolates have been generated. Several methods and molecular tools have been used for genetic manipulation of various Acinetobacter spp. Here, we review recent developments of various genetic tools used for modification of the A. baumannii genome, including various ways to inactivate gene function, chromosomal integration and transposon mutagenesis.
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Affiliation(s)
- Indranil Biswas
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160, USA
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