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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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2
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Vargas-Lizarazo AY, Ali MA, Mazumder NA, Kohli GM, Zaborska M, Sons T, Garnett M, Senanayake IM, Goodson BM, Vargas-Muñiz JM, Pond A, Jensik PJ, Olson ME, Hamilton-Brehm SD, Kohli P. Electrically polarized nanoscale surfaces generate reactive oxygenated and chlorinated species for deactivation of microorganisms. SCIENCE ADVANCES 2024; 10:eado5555. [PMID: 39093965 DOI: 10.1126/sciadv.ado5555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2024] [Accepted: 06/27/2024] [Indexed: 08/04/2024]
Abstract
Because of the decreasing supply of new antibiotics, recent outbreaks of infectious diseases, and the emergence of antibiotic-resistant microorganisms, it is imperative to develop new effective strategies for deactivating a broad spectrum of microorganisms and viruses. We have implemented electrically polarized nanoscale metallic (ENM) coatings that deactivate a wide range of microorganisms including Gram-negative and Gram-positive bacteria with greater than 6-log reduction in less than 10 minutes of treatment. The electrically polarized devices were also effective in deactivating lentivirus and Candida albicans. The key to the high deactivation effectiveness of ENM devices is electrochemical production of micromolar cuprous ions, which mediated reduction of oxygen to hydrogen peroxide. Formation of highly damaging species, hydroxyl radicals and hypochlorous acid, from hydrogen peroxide contributed to antimicrobial properties of the ENM devices. The electric polarization of nanoscale coatings represents an unconventional tool for deactivating a broad spectrum of microorganisms through in situ production of reactive oxygenated and chlorinated species.
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Affiliation(s)
- Annie Y Vargas-Lizarazo
- School of Chemical and Biomolecular Sciences, Southern Illinois University, Carbondale, IL 62901, USA
| | - M Aswad Ali
- School of Chemical and Biomolecular Sciences, Southern Illinois University, Carbondale, IL 62901, USA
| | - Nehal A Mazumder
- School of Chemical and Biomolecular Sciences, Southern Illinois University, Carbondale, IL 62901, USA
| | | | - Miroslava Zaborska
- School of Chemical and Biomolecular Sciences, Southern Illinois University, Carbondale, IL 62901, USA
| | - Tyler Sons
- Department of Microbiology, Southern Illinois University, Carbondale, IL 62901, USA
| | - Michelle Garnett
- Department of Microbiology, Southern Illinois University, Carbondale, IL 62901, USA
| | - Ishani M Senanayake
- School of Chemical and Biomolecular Sciences, Southern Illinois University, Carbondale, IL 62901, USA
| | - Boyd M Goodson
- School of Chemical and Biomolecular Sciences, Southern Illinois University, Carbondale, IL 62901, USA
| | - José M Vargas-Muñiz
- Department of Microbiology, Southern Illinois University, Carbondale, IL 62901, USA
| | - Amber Pond
- Department of Anatomy, Southern Illinois University School of Medicine, Carbondale, IL 62901, USA
| | - Philip J Jensik
- Department of Physiology, Southern Illinois University School of Medicine, Carbondale, IL 62901, USA
| | - Michael E Olson
- Department of Medical Microbiology, Immunology and Cell Biology, School of Medicine, Southern Illinois University, Springfield, IL 62702, USA
| | | | - Punit Kohli
- School of Chemical and Biomolecular Sciences, Southern Illinois University, Carbondale, IL 62901, USA
- Integrated Microscopy and Graphics Expertise (IMAGE) Center, Southern Illinois University, Carbondale, IL 62901, USA
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3
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Sabatini A, Lucidi M, Ciolfi S, Vuotto C, De Bardi M, Visca P, Battistini L, Visaggio D, Volpe E. Innate immune mechanisms promote human response to Acinetobacter baumannii infection. Eur J Immunol 2024:e2451170. [PMID: 39072714 DOI: 10.1002/eji.202451170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 07/15/2024] [Accepted: 07/17/2024] [Indexed: 07/30/2024]
Abstract
Acinetobacter baumannii is an opportunistic Gram-negative bacterium representing one of the leading causes of ventilator-associated pneumonia. The development of pneumonia results from a complex interplay between pathogens and pulmonary innate mucosal immunity. Therefore, the knowledge of the host immune responses is pivotal for the development of effective therapeutics to treat A. baumannii infections. Previous studies were conducted using cell lines and animal models, but a comprehensive understanding of the interaction between A. baumannii and primary human immune cells is still lacking. To bridge this gap, we investigated the response of primary monocytes, macrophages, and dendritic cells to the A. baumannii-type strain and an epidemic clinical isolate. We found that all immune cells trigger different responses when interacting with A. baumannii. In particular, macrophages and monocytes mediate bacterial clearance, whereas monocytes and dendritic cells activate a late response through the production of cytokines, chemokines, and the expression of co-stimulatory molecules. The epidemic strain induces lower expression of interleukin-10 and CD80 compared with the type strain, potentially constituting two immune evasion strategies.
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Affiliation(s)
- Andrea Sabatini
- Molecular Neuroimmunology Unit, IRCSS Fondazione Santa Lucia, Rome, Italy
| | - Massimiliano Lucidi
- Department of Science, University Roma Tre, Rome, Italy
- National Biodiversity Future Center (NBFC), Palermo, Italy
| | - Serena Ciolfi
- Molecular Neuroimmunology Unit, IRCSS Fondazione Santa Lucia, Rome, Italy
| | - Claudia Vuotto
- Neuromicrobiology Unit, IRCSS Fondazione Santa Lucia, Rome, Italy
| | - Marco De Bardi
- Neuroimmunology Unit, IRCSS Fondazione Santa Lucia, Rome, Italy
| | - Paolo Visca
- Department of Science, University Roma Tre, Rome, Italy
- Molecular Microbiology and Microbiomics, IRCSS Fondazione Santa Lucia, Rome, Italy
| | - Luca Battistini
- Neuroimmunology Unit, IRCSS Fondazione Santa Lucia, Rome, Italy
| | - Daniela Visaggio
- Department of Science, University Roma Tre, Rome, Italy
- National Biodiversity Future Center (NBFC), Palermo, Italy
- Molecular Microbiology and Microbiomics, IRCSS Fondazione Santa Lucia, Rome, Italy
| | - Elisabetta Volpe
- Molecular Neuroimmunology Unit, IRCSS Fondazione Santa Lucia, Rome, Italy
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4
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Oyejobi GK, Zhang X, Xiong D, Xue H, Shi M, Yang H, Wei H. Phage-Bacterial Interaction Alters Phenotypes Associated with Virulence in Acinetobacter baumannii. Viruses 2024; 16:743. [PMID: 38793624 PMCID: PMC11125765 DOI: 10.3390/v16050743] [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: 03/27/2024] [Revised: 04/30/2024] [Accepted: 05/06/2024] [Indexed: 05/26/2024] Open
Abstract
Bacteriophages exert strong selection on their bacterial hosts to evolve resistance. At the same time, the fitness costs on bacteria following phage resistance may change their virulence, which may affect the therapeutic outcomes of phage therapy. In this study, we set out to assess the costs of phage resistance on the in vitro virulence of priority 1 nosocomial pathogenic bacterium, Acinetobacter baumannii. By subjecting phage-resistant variant Ev5-WHG of A. baumannii WHG40004 to several in vitro virulence profiles, we found that its resistance to phage is associated with reduced fitness in host microenvironments. Also, the mutant exhibited impaired adhesion and invasion to mammalian cells, as well as increased susceptibility to macrophage phagocytosis. Furthermore, the whole-genome sequencing of the mutant revealed that there exist multiple mutations which may play a role in phage resistance and altered virulence. Altogether, this study demonstrates that resistance to phage can significantly alter phenotypes associated with virulence in Acinetobacter baumannii.
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Affiliation(s)
- Greater Kayode Oyejobi
- Key Laboratory of Special Pathogens and Biosafety, Center for Biosafety Mega-Science, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China; (G.K.O.); (X.Z.); (D.X.); (H.X.); (M.S.)
- University of Chinese Academy of Sciences, Beijing 100049, China
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (Ministry of Education), School of Pharmaceutical Sciences, Wuhan University, Wuhan 430072, China
| | - Xiaoxu Zhang
- Key Laboratory of Special Pathogens and Biosafety, Center for Biosafety Mega-Science, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China; (G.K.O.); (X.Z.); (D.X.); (H.X.); (M.S.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Dongyan Xiong
- Key Laboratory of Special Pathogens and Biosafety, Center for Biosafety Mega-Science, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China; (G.K.O.); (X.Z.); (D.X.); (H.X.); (M.S.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Heng Xue
- Key Laboratory of Special Pathogens and Biosafety, Center for Biosafety Mega-Science, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China; (G.K.O.); (X.Z.); (D.X.); (H.X.); (M.S.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mengjuan Shi
- Key Laboratory of Special Pathogens and Biosafety, Center for Biosafety Mega-Science, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China; (G.K.O.); (X.Z.); (D.X.); (H.X.); (M.S.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hang Yang
- Key Laboratory of Special Pathogens and Biosafety, Center for Biosafety Mega-Science, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China; (G.K.O.); (X.Z.); (D.X.); (H.X.); (M.S.)
| | - Hongping Wei
- Key Laboratory of Special Pathogens and Biosafety, Center for Biosafety Mega-Science, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China; (G.K.O.); (X.Z.); (D.X.); (H.X.); (M.S.)
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5
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Maure A, Robino E, Van der Henst C. The intracellular life of Acinetobacter baumannii. Trends Microbiol 2023; 31:1238-1250. [PMID: 37487768 DOI: 10.1016/j.tim.2023.06.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 06/16/2023] [Accepted: 06/23/2023] [Indexed: 07/26/2023]
Abstract
Acinetobacter baumannii is a Gram-negative opportunistic bacterium responsible for nosocomial and community-acquired infections. This pathogen is globally disseminated and associated with high levels of antibiotic resistance, which makes it an important threat to human health. Recently, new evidence showed that several A. baumannii isolates can survive and proliferate within eukaryotic professional and/or nonprofessional phagocytic cells, with in vivo consequences. This review provides updated information and describes the tools that A. baumannii possesses to adhere, colonize, and replicate in host cells. Additionally, we emphasize the high genetic and phenotypic heterogeneity detected amongst A. baumannii isolates and its impact on the bacterial intracellular features. We also discuss the need for standardized methods to characterize this pathogen robustly and consequently consider some strains as facultative intracellular bacteria.
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Affiliation(s)
- Alexandra Maure
- Microbial Resistance and Drug Discovery, VIB-VUB Center for Structural Biology, VIB, Flanders Institute for Biotechnology, Brussels, Belgium; Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Etienne Robino
- Microbial Resistance and Drug Discovery, VIB-VUB Center for Structural Biology, VIB, Flanders Institute for Biotechnology, Brussels, Belgium; Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Charles Van der Henst
- Microbial Resistance and Drug Discovery, VIB-VUB Center for Structural Biology, VIB, Flanders Institute for Biotechnology, Brussels, Belgium; Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium.
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6
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McGuffey JC, Jackson-Litteken CD, Di Venanzio G, Zimmer AA, Lewis JM, Distel JS, Kim KQ, Zaher HS, Alfonzo J, Scott NE, Feldman MF. The tRNA methyltransferase TrmB is critical for Acinetobacter baumannii stress responses and pulmonary infection. mBio 2023; 14:e0141623. [PMID: 37589464 PMCID: PMC10653896 DOI: 10.1128/mbio.01416-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 07/10/2023] [Indexed: 08/18/2023] Open
Abstract
IMPORTANCE As deficiencies in tRNA modifications have been linked to human diseases such as cancer and diabetes, much research has focused on the modifications' impacts on translational regulation in eukaryotes. However, the significance of tRNA modifications in bacterial physiology remains largely unexplored. In this paper, we demonstrate that the m7G tRNA methyltransferase TrmB is crucial for a top-priority pathogen, Acinetobacter baumannii, to respond to stressors encountered during infection, including oxidative stress, low pH, and iron deprivation. We show that loss of TrmB dramatically attenuates a murine pulmonary infection. Given the current efforts to use another tRNA methyltransferase, TrmD, as an antimicrobial therapeutic target, we propose that TrmB, and other tRNA methyltransferases, may also be viable options for drug development to combat multidrug-resistant A. baumannii.
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Affiliation(s)
- Jenna C. McGuffey
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
| | - Clay D. Jackson-Litteken
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
| | - Gisela Di Venanzio
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
| | - Aubree A. Zimmer
- Department of Microbiology and The Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA
| | - Jessica M. Lewis
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
| | - Jesus S. Distel
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
| | - Kyusik Q. Kim
- Department of Biology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Hani S. Zaher
- Department of Biology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Juan Alfonzo
- Department of Microbiology and The Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA
| | - Nichollas E. Scott
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
| | - Mario F. Feldman
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
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7
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Li Y, Liu L, Xiao C, Sun B, Luo S, Yang D, Zhang X, Huang T, Yu Z, Li X. Outer membrane protein A of Acinetobacter baumannii regulates pulmonary inflammation through the TLR2-NF-κB pathway. Vet Microbiol 2023; 284:109812. [PMID: 37343456 DOI: 10.1016/j.vetmic.2023.109812] [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: 10/01/2022] [Revised: 06/07/2023] [Accepted: 06/10/2023] [Indexed: 06/23/2023]
Abstract
Acinetobacter baumannii (A. baumannii) is characterized by a high prevalence of drug resistance; how to effectively treat it is still a major clinical challenge. Our previous experiments confirmed that ompA, which is one of the most well-characterized virulence factors, may be dependent on the caspase-1 pathway-stimulated expression of NLRP3 inflammasome to enhance inflammation. TLRs (i.e., TLR2, etc.) is the initiating signal for NLRP3 inflammasome activation; how it relates to ompA in its underlying pathogenic mechanism is not clear. In this study, we proofed that ompA promoted NLRP3 inflammasome activation while the TLR2-NF-κB pathway was also activated after A. baumannii infection. Additionally, the expression of NLRP3 inflammasome-associated proteins and genes was inhibited by silencing TLR2 and NLRP3. This indicated that ompA might depend on the TLR2-NF-κB pathway to assemble and activate the NLRP3 inflammasome. OmpA promoted the assembly of the NLRP3 inflammasome through the TLR2-NF-κB pathway and inhibited the degradation of caspase-1 by the proteasome so that a large number of mature IL-1β/IL-18 and other proinflammatory factors were released extracellularly to enhance the body's inflammatory response. Taken together, the results of the joint pre-study confirmed a novel TLR2-NF-κB/NLRP3/caspase-1-modulated mechanism underpinning ompA activity, the NLRP3 inflammasome pathway may be as a potential immunomodulatory target against A. baumannii infections.
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Affiliation(s)
- Yumei Li
- Department of Anatomy, School of Basic Medical Sciences, Guizhou Medical University/ Department of Nephrology, Guiyang First People's Hospital, Guiyang, Guizhou 550025, China
| | - Laibing Liu
- Department of Neurosurgery, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550004, China
| | - Chaolun Xiao
- Department of Anatomy, School of Basic Medical Sciences, Guizhou Medical University/ Department of Nephrology, Guiyang First People's Hospital, Guiyang, Guizhou 550025, China
| | - Baofei Sun
- Department of Anatomy, School of Basic Medical Sciences, Guizhou Medical University/ Department of Nephrology, Guiyang First People's Hospital, Guiyang, Guizhou 550025, China
| | - Shipeng Luo
- Department of Anatomy, School of Basic Medical Sciences, Guizhou Medical University/ Department of Nephrology, Guiyang First People's Hospital, Guiyang, Guizhou 550025, China
| | - Dan Yang
- Department of Anatomy, School of Basic Medical Sciences, Guizhou Medical University/ Department of Nephrology, Guiyang First People's Hospital, Guiyang, Guizhou 550025, China
| | - Xiangyan Zhang
- Department of Respiratory and Critical Medicine, Guizhou Provincial People's Hospital,Guiyang, Guiyang, Guizhou 550006, China
| | - Tao Huang
- Department of Anatomy, School of Basic Medical Sciences, Guizhou Medical University/ Department of Nephrology, Guiyang First People's Hospital, Guiyang, Guizhou 550025, China
| | - Zijiang Yu
- Department of Anatomy, School of Basic Medical Sciences, Guizhou Medical University/ Department of Nephrology, Guiyang First People's Hospital, Guiyang, Guizhou 550025, China.
| | - Xiaoying Li
- Department of Anatomy, School of Basic Medical Sciences, Guizhou Medical University/ Department of Nephrology, Guiyang First People's Hospital, Guiyang, Guizhou 550025, China
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Distel JS, Di Venanzio G, Mackel JJ, Rosen DA, Feldman MF. Replicative Acinetobacter baumannii strains interfere with phagosomal maturation by modulating the vacuolar pH. PLoS Pathog 2023; 19:e1011173. [PMID: 37294840 DOI: 10.1371/journal.ppat.1011173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 05/23/2023] [Indexed: 06/11/2023] Open
Abstract
Bacterial pneumonia is a common infection of the lower respiratory tract that can afflict patients of all ages. Multidrug-resistant strains of Acinetobacter baumannii are increasingly responsible for causing nosocomial pneumonias, thus posing an urgent threat. Alveolar macrophages play a critical role in overcoming respiratory infections caused by this pathogen. Recently, we and others have shown that new clinical isolates of A. baumannii, but not the common lab strain ATCC 19606 (19606), can persist and replicate in macrophages within spacious vacuoles that we called Acinetobacter Containing Vacuoles (ACV). In this work, we demonstrate that the modern A. baumannii clinical isolate 398, but not the lab strain 19606, can infect alveolar macrophages and produce ACVs in vivo in a murine pneumonia model. Both strains initially interact with the alveolar macrophage endocytic pathway, as indicated by EEA1 and LAMP1 markers; however, the fate of these strains diverges at a later stage. While 19606 is eliminated in an autophagy pathway, 398 replicates in ACVs and are not degraded. We show that 398 reverts the natural acidification of the phagosome by secreting large amounts of ammonia, a by-product of amino acid catabolism. We propose that this ability to survive within macrophages may be critical for the persistence of clinical A. baumannii isolates in the lung during a respiratory infection.
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Affiliation(s)
- Jesus S Distel
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - Gisela Di Venanzio
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - Joseph J Mackel
- Department of Pediatrics, Division of Infectious Diseases, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - David A Rosen
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, Missouri, United States of America
- Department of Pediatrics, Division of Infectious Diseases, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - Mario F Feldman
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, Missouri, United States of America
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9
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Micelli C, Dai Y, Raustad N, Isberg RR, Dowson CG, Lloyd AJ, Geisinger E, Crow A, Roper DI. A conserved zinc-binding site in Acinetobacter baumannii PBP2 required for elongasome-directed bacterial cell shape. Proc Natl Acad Sci U S A 2023; 120:e2215237120. [PMID: 36787358 PMCID: PMC9974482 DOI: 10.1073/pnas.2215237120] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 01/09/2023] [Indexed: 02/15/2023] Open
Abstract
Acinetobacter baumannii is a gram-negative bacterial pathogen that causes challenging nosocomial infections. β-lactam targeting of penicillin-binding protein (PBP)-mediated cell wall peptidoglycan (PG) formation is a well-established antimicrobial strategy. Exposure to carbapenems or zinc (Zn)-deprived growth conditions leads to a rod-to-sphere morphological transition in A. baumannii, an effect resembling that caused by deficiency in the RodA-PBP2 PG synthesis complex required for cell wall elongation. While it is recognized that carbapenems preferentially acylate PBP2 in A. baumannii and therefore block the transpeptidase function of the RodA-PBP2 system, the molecular details underpinning cell wall elongation inhibition upon Zn starvation remain undefined. Here, we report the X-ray crystal structure of A. baumannii PBP2, revealing an unexpected Zn coordination site in the transpeptidase domain required for protein stability. Mutations in the Zn-binding site of PBP2 cause a loss of bacterial rod shape and increase susceptibility to β-lactams, therefore providing a direct rationale for cell wall shape maintenance and Zn homeostasis in A. baumannii. Furthermore, the Zn-coordinating residues are conserved in various β- and γ-proteobacterial PBP2 orthologs, consistent with a widespread Zn-binding requirement for function that has been previously unknown. Due to the emergence of resistance to virtually all marketed antibiotic classes, alternative or complementary antimicrobial strategies need to be explored. These findings offer a perspective for dual inhibition of Zn-dependent PG synthases and metallo-β-lactamases by metal chelating agents, considered the most sought-after adjuvants to restore β-lactam potency against gram-negative bacteria.
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Affiliation(s)
- Carmina Micelli
- School of Life Sciences, University of Warwick, CoventryCV4 7AL, United Kingdom
| | - Yunfei Dai
- Department of Biology, Northeastern University, Boston, MA02115
| | - Nicole Raustad
- Department of Biology, Northeastern University, Boston, MA02115
| | - Ralph R. Isberg
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA02111
| | | | - Adrian J. Lloyd
- School of Life Sciences, University of Warwick, CoventryCV4 7AL, United Kingdom
| | | | - Allister Crow
- School of Life Sciences, University of Warwick, CoventryCV4 7AL, United Kingdom
| | - David I. Roper
- School of Life Sciences, University of Warwick, CoventryCV4 7AL, United Kingdom
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10
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The Impact of Colistin Resistance on the Activation of Innate Immunity by Lipopolysaccharide Modification. Infect Immun 2023; 91:e0001223. [PMID: 36722977 PMCID: PMC9933656 DOI: 10.1128/iai.00012-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Colistin resistance is acquired by different lipopolysaccharide (LPS) modifications. We proposed to evaluate the of effect in vivo colistin resistance acquisition on the innate immune response. We used a pair of ST11 clone Klebsiella pneumoniae strains: an OXA-48, CTX-M-15 K. pneumoniae strain susceptible to colistin (CS-Kp) isolated from a urinary infection and its colistin-resistant variant (CR-Kp) from the same patient after prolonged treatment with colistin. No mutation of previously described genes for colistin resistance (pmrA, pmrB, mgrB, phoP/Q, arnA, arnC, arnT, ugdH, and crrAB) was found in the CR-Kp genome; however, LPS modifications were characterized by negative-ion matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry. The strains were cocultured with human monocytes to determine their survival after phagocytosis and induction to apoptosis. Also, monocytes were stimulated with bacterial LPS to study cytokine and immune checkpoint production. The addition of 4-amino-4-deoxy-l-arabinose (Ara4N) to lipid A of CR-Kp accounted for the colistin resistance. CR-Kp survived significantly longer inside human monocytes after being phagocytosed than did the CS-Kp strain. In addition, LPS from CR-Kp induced both higher apoptosis in monocytes and higher levels of cytokine and immune checkpoint production than LPS from CS-Kp. Our data reveal a variable impact of colistin resistance on the innate immune system, depending on the responsible mechanism. Adding Ara4N to LPS in K. pneumoniae increases bacterial survival after phagocytosis and elicits a higher inflammatory response than its colistin-susceptible counterpart.
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11
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Distel JS, Di Venanzio G, Mackel JJ, Rosen DA, Feldman MF. Replicative Acinetobacter baumannii strains interfere with phagosomal maturation by modulating the vacuolar pH. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.02.526753. [PMID: 36778331 PMCID: PMC9915592 DOI: 10.1101/2023.02.02.526753] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Bacterial pneumonia is a common infection of the lower respiratory tract that can afflict patients of all ages. Multidrug-resistant strains of Acinetobacter baumannii are increasingly responsible for causing nosocomial pneumonias, thus posing an urgent threat. Alveolar macrophages play a critical role in overcoming respiratory infections caused by this pathogen. Recently, we and others have shown that new clinical isolates of A. baumannii , but not the common lab strain ATCC 19606 (19606), can persist and replicate in macrophages within spacious vacuoles that we called A cinetobacter C ontaining V acuoles (ACV). In this work, we demonstrate that the modern A. baumannii clinical isolate 398, but not the lab strain 19606, can infect alveolar macrophages and produce ACVs in vivo in a murine pneumonia model. Both strains initially interact with the alveolar macrophage endocytic pathway, as indicated by EEA1 and LAMP1 markers; however, the fate of these strains diverges at a later stage. While 19606 is eliminated in an autophagy pathway, 398 replicates in ACVs and are not degraded. We show that 398 reverts the natural acidification of the phagosome by secreting large amounts of ammonia, a by-product of amino acid catabolism. We propose that this ability to survive within macrophages may be critical for the persistence of clinical A. baumannii isolates in the lung during a respiratory infection.
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Affiliation(s)
- Jesus S. Distel
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - Gisela Di Venanzio
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - Joseph J. Mackel
- Department of Pediatrics, Division of Infectious Diseases, Washington University School of Medicine, Saint Louis, MO, United States
| | - David A Rosen
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, Missouri, United States of America.,Department of Pediatrics, Division of Infectious Diseases, Washington University School of Medicine, Saint Louis, MO, United States
| | - Mario F. Feldman
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, Missouri, United States of America.,Corresponding author: Mario F. Feldman,
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12
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Sepahvand S, Madani M, Sepahvand H, Davarpanah MA. Comparative assessment of the mouse immune responses to colistin-resistant and colistin-sensitive isolates of Acinetobacter baumannii. Microb Pathog 2022; 173:105834. [DOI: 10.1016/j.micpath.2022.105834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 10/11/2022] [Accepted: 10/12/2022] [Indexed: 11/07/2022]
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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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Liu Z, Xu W. Neutrophil and Macrophage Response in Acinetobacter Baumannii Infection and Their Relationship to Lung Injury. Front Cell Infect Microbiol 2022; 12:890511. [PMID: 35873147 PMCID: PMC9298752 DOI: 10.3389/fcimb.2022.890511] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 06/08/2022] [Indexed: 11/25/2022] Open
Abstract
Acinetobacter baumannii (AB) infection has become a threat to global public health. AB is one of the main pathogens causing nosocomial infections, especially ventilator-associated pneumonia. AB easily develops resistance against a variety of antibiotics, which makes the treatment of AB infections difficult. Therefore, it is necessary to study new treatment plans like anti-infection immunity. Both animal models of AB infection and in vitro cell experiments show that macrophages are activated in the early stage of the immune response and regulate the recruitment of neutrophils, thus playing a role in clearing AB. AB components and the immune responses they induce can lead to injury of the infected organ, mostly in the lungs. Understanding the response of innate immunity to ABs at different stages after infection and the relationship between the response and lung injury can help to develop new immunotherapy methods and prevent lung injury. This article provides a comprehensive review of the response of neutrophils and macrophages to AB infection and their association with lung injury to develop effective therapies for AB infection and prevent lung injury.
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Affiliation(s)
- Zhaojun Liu
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, China
| | - Wei Xu
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, China
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15
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Sato Y, Hatayama N, Ubagai T, Tansho-Nagakawa S, Ono Y, Yoshino Y. Tigecycline Suppresses the Virulence Factors of Multidrug-Resistant Acinetobacter baumannii Allowing Human Neutrophils to Act. Infect Drug Resist 2022; 15:3357-3368. [PMID: 35789794 PMCID: PMC9250330 DOI: 10.2147/idr.s368890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 06/16/2022] [Indexed: 11/23/2022] Open
Abstract
Purpose To determine the ability of human neutrophils to kill multidrug-resistant Acinetobacter baumannii (MDRAB) in the presence of tigecycline (TGC). Methods Clinical isolates of MDRAB were cultured with human neutrophils and H2O2 in the presence of TGC. The numbers of viable bacteria, catalase activity, gene expression at the K locus of the MDRAB, reactive oxygen species (ROS) production, and granule exocytosis in human neutrophils were determined. Results There was a time-dependent increase in the numbers of MDRAB after co-culturing with human neutrophils, whereas there was a significant decrease in the MDRAB numbers when co-cultured with both, human neutrophils and TGC for 6 h. The presence or absence of TGC did not affect total ROS production or the expression of CD11b, CD15, and CD63 on human neutrophils occurred when co-cultured with MDRAB. TGC significantly suppressed catalase activity and gene expression at the K locus of MDRAB, and significantly reduced the thickness of the capsule. Additionally, the bacterial viability of TGC-treated MDRAB cultured with H2O2 was lower than that without H2O2 after 6 h of culture. Conclusion TGC significantly suppressed the expression of catalase and the capsule in MDRAB without adverse effects on neutrophil function, allowing human neutrophils to kill MDRAB. TGC is an effective antibiotic for treating MDRAB infections.
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Affiliation(s)
- Yoshinori Sato
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Itabashi-ku, Tokyo, 173-8605, Japan
| | - Nami Hatayama
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Itabashi-ku, Tokyo, 173-8605, Japan
| | - Tsuneyuki Ubagai
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Itabashi-ku, Tokyo, 173-8605, Japan
| | - Shigeru Tansho-Nagakawa
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Itabashi-ku, Tokyo, 173-8605, Japan
| | - Yasuo Ono
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Itabashi-ku, Tokyo, 173-8605, Japan.,Teikyo Heisei University, Faculty of Health and Medical Science, Toshima-ku, Tokyo, 170-8445, Japan
| | - Yusuke Yoshino
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Itabashi-ku, Tokyo, 173-8605, Japan
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16
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Lim Ah Tock M, Combrinck S, Kamatou G, Chen W, Van Vuuren S, Viljoen A. Antibacterial Screening, Biochemometric and Bioautographic Evaluation of the Non-Volatile Bioactive Components of Three Indigenous South African Salvia Species. Antibiotics (Basel) 2022; 11:antibiotics11070901. [PMID: 35884155 PMCID: PMC9312202 DOI: 10.3390/antibiotics11070901] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 06/29/2022] [Accepted: 06/29/2022] [Indexed: 01/25/2023] Open
Abstract
Salvia africana-lutea L., S. lanceolata L., and S. chamelaeagnea L. are used in South Africa as traditional medicines to treat infections. This paper describes an in-depth investigation into their antibacterial activities to identify bioactive compounds. Methanol extracts from 81 samples were screened against seven bacterial pathogens, using the microdilution assay. Biochemometric models were constructed using data derived from minimum inhibitory concentration (MIC) and ultra-performance liquid chromatography-mass spectrometry data. Active molecules in selected extracts were tentatively identified using high-performance thin layer chromatography (HPTLC), combined with bioautography, and finally, by analysis of active zone eluates by mass spectrometry (MS) via a dedicated interface. Salvia chamelaeagnea displayed notable activity towards all seven pathogens, and the activity, reflected by MICs, was superior to that of the other two species, as confirmed through ANOVA. Biochemometric models highlighted potentially bioactive compounds, including rosmanol methyl ether, epiisorosmanol methyl ether and carnosic acid. Bioautography assays revealed inhibition zones against A. baumannii, an increasingly multidrug-resistant pathogen. Mass spectral data of the eluted zones correlated to those revealed through biochemometric analysis. The study demonstrates the application of a biochemometric approach, bioautography, and direct MS analysis as useful tools for the rapid identification of bioactive constituents in plant extracts.
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Affiliation(s)
- Margaux Lim Ah Tock
- Department of Pharmaceutical Sciences, Faculty of Science, Tshwane University of Technology, Pretoria 0001, South Africa; (M.L.A.T.); (S.C.); (G.K.); (W.C.)
| | - Sandra Combrinck
- Department of Pharmaceutical Sciences, Faculty of Science, Tshwane University of Technology, Pretoria 0001, South Africa; (M.L.A.T.); (S.C.); (G.K.); (W.C.)
| | - Guy Kamatou
- Department of Pharmaceutical Sciences, Faculty of Science, Tshwane University of Technology, Pretoria 0001, South Africa; (M.L.A.T.); (S.C.); (G.K.); (W.C.)
| | - Weiyang Chen
- Department of Pharmaceutical Sciences, Faculty of Science, Tshwane University of Technology, Pretoria 0001, South Africa; (M.L.A.T.); (S.C.); (G.K.); (W.C.)
| | - Sandy Van Vuuren
- Department of Pharmacy and Pharmacology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Johannesburg 2193, South Africa;
| | - Alvaro Viljoen
- Department of Pharmaceutical Sciences, Faculty of Science, Tshwane University of Technology, Pretoria 0001, South Africa; (M.L.A.T.); (S.C.); (G.K.); (W.C.)
- SAMRC Herbal Drugs Research Unit, Faculty of Science, Tshwane University of Technology, Pretoria 0001, South Africa
- Correspondence:
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17
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Djahanschiri B, Di Venanzio G, Distel JS, Breisch J, Dieckmann MA, Goesmann A, Averhoff B, Göttig S, Wilharm G, Feldman MF, Ebersberger I. Evolutionarily stable gene clusters shed light on the common grounds of pathogenicity in the Acinetobacter calcoaceticus-baumannii complex. PLoS Genet 2022; 18:e1010020. [PMID: 35653398 PMCID: PMC9162365 DOI: 10.1371/journal.pgen.1010020] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 04/04/2022] [Indexed: 11/19/2022] Open
Abstract
Nosocomial pathogens of the Acinetobacter calcoaceticus-baumannii (ACB) complex are a cautionary example for the world-wide spread of multi- and pan-drug resistant bacteria. Aiding the urgent demand for novel therapeutic targets, comparative genomics studies between pathogens and their apathogenic relatives shed light on the genetic basis of human-pathogen interaction. Yet, existing studies are limited in taxonomic scope, sensing of the phylogenetic signal, and resolution by largely analyzing genes independent of their organization in functional gene clusters. Here, we explored more than 3,000 Acinetobacter genomes in a phylogenomic framework integrating orthology-based phylogenetic profiling and microsynteny conservation analyses. We delineate gene clusters in the type strain A. baumannii ATCC 19606 whose evolutionary conservation indicates a functional integration of the subsumed genes. These evolutionarily stable gene clusters (ESGCs) reveal metabolic pathways, transcriptional regulators residing next to their targets but also tie together sub-clusters with distinct functions to form higher-order functional modules. We shortlisted 150 ESGCs that either co-emerged with the pathogenic ACB clade or are preferentially found therein. They provide a high-resolution picture of genetic and functional changes that coincide with the manifestation of the pathogenic phenotype in the ACB clade. Key innovations are the remodeling of the regulatory-effector cascade connecting LuxR/LuxI quorum sensing via an intermediate messenger to biofilm formation, the extension of micronutrient scavenging systems, and the increase of metabolic flexibility by exploiting carbon sources that are provided by the human host. We could show experimentally that only members of the ACB clade use kynurenine as a sole carbon and energy source, a substance produced by humans to fine-tune the antimicrobial innate immune response. In summary, this study provides a rich and unbiased set of novel testable hypotheses on how pathogenic Acinetobacter interact with and ultimately infect their human host. It is a comprehensive resource for future research into novel therapeutic strategies. The spread of multi- and pan-drug resistant bacterial pathogens is a worldwide threat to human health. Understanding the genetics of host colonization and infection can substantially help in devising novel ways of treatment. Acinetobacter baumannii, a nosocomial pathogen ranked top by the World Health Organization in the list of bacteria for which novel therapeutic approaches are needed, is a prime example. Here, we have carved out the genetic make-up that distinguishes A. baumannii and its pathogenic next relatives from other and mostly apathogenic Acinetobacter species. We found a rich spectrum of pathways and regulatory modules that reveal how the pathogens have modified biofilm formation, iron scavenging, and their carbohydrate metabolism to adapt to their human host. Among these, the capability to metabolize kynurenine is particularly intriguing. Humans produce this substance to contain bacterial invaders and to fine-tune the innate immune response. But A. baumannii and closely related pathogens found a way to feed on kynurenine. This suggests that the pathogens might be able to dysregulate the human immune response. In summary, our study substantially deepens the understanding of how a highly critical pathogen interacts with its host, which substantially eases the identification of novel targets for innovative therapeutic strategies.
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Affiliation(s)
- Bardya Djahanschiri
- Applied Bioinformatics Group, Inst. of Cell Biology and Neuroscience, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Gisela Di Venanzio
- Department of Molecular Microbiology, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Jesus S. Distel
- Department of Molecular Microbiology, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Jennifer Breisch
- Inst. of Molecular Biosciences, Department of Molecular Microbiology and Bioenergetics, Goethe University Frankfurt, Frankfurt am Main, Germany
| | | | - Alexander Goesmann
- Bioinformatics and Systems Biology, Justus Liebig University Gießen, Gießen, Germany
| | - Beate Averhoff
- Inst. of Molecular Biosciences, Department of Molecular Microbiology and Bioenergetics, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Stephan Göttig
- Institute for Medical Microbiology and Infection Control, University Hospital, Goethe University, Frankfurt, Germany
| | | | - Mario F. Feldman
- Department of Molecular Microbiology, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Ingo Ebersberger
- Applied Bioinformatics Group, Inst. of Cell Biology and Neuroscience, Goethe University Frankfurt, Frankfurt am Main, Germany
- Senckenberg Biodiversity and Climate Research Centre (S-BIKF), Frankfurt am Main, Germany
- LOEWE Center for Translational Biodiversity Genomics (TBG), Frankfurt am Main, Germany
- * E-mail:
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18
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Kho ZY, Azad MAK, Han ML, Zhu Y, Huang C, Schittenhelm RB, Naderer T, Velkov T, Selkrig J, Zhou Q(T, Li J. Correlative proteomics identify the key roles of stress tolerance strategies in Acinetobacter baumannii in response to polymyxin and human macrophages. PLoS Pathog 2022; 18:e1010308. [PMID: 35231068 PMCID: PMC8887720 DOI: 10.1371/journal.ppat.1010308] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 01/26/2022] [Indexed: 11/19/2022] Open
Abstract
The opportunistic pathogen Acinetobacter baumannii possesses stress tolerance strategies against host innate immunity and antibiotic killing. However, how the host-pathogen-antibiotic interaction affects the overall molecular regulation of bacterial pathogenesis and host response remains unexplored. Here, we simultaneously investigate proteomic changes in A. baumannii and macrophages following infection in the absence or presence of the polymyxins. We discover that macrophages and polymyxins exhibit complementary effects to disarm several stress tolerance and survival strategies in A. baumannii, including oxidative stress resistance, copper tolerance, bacterial iron acquisition and stringent response regulation systems. Using the spoT mutant strains, we demonstrate that bacterial cells with defects in stringent response exhibit enhanced susceptibility to polymyxin killing and reduced survival in infected mice, compared to the wild-type strain. Together, our findings highlight that better understanding of host-pathogen-antibiotic interplay is critical for optimization of antibiotic use in patients and the discovery of new antimicrobial strategy to tackle multidrug-resistant bacterial infections.
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Affiliation(s)
- Zhi Ying Kho
- Biomedicine Discovery Institute, Infection Program and Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - Mohammad A. K. Azad
- Biomedicine Discovery Institute, Infection Program and Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - Mei-Ling Han
- Biomedicine Discovery Institute, Infection Program and Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - Yan Zhu
- Biomedicine Discovery Institute, Infection Program and Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - Cheng Huang
- Monash Proteomics & Metabolomics Facility, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Ralf B. Schittenhelm
- Monash Proteomics & Metabolomics Facility, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Thomas Naderer
- Biomedicine Discovery Institute, Infection Program, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - Tony Velkov
- Department of Pharmacology and Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Joel Selkrig
- European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg, Germany
| | - Qi (Tony) Zhou
- Department of Industrial and Physical Pharmacy, Purdue University, West Lafayette, Indiana, United States of America
| | - Jian Li
- Biomedicine Discovery Institute, Infection Program and Department of Microbiology, Monash University, Clayton, Victoria, Australia
- * E-mail:
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19
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Abstract
The spread of antibiotic-resistant Acinetobacter baumannii poses a significant threat to public health worldwide. This nosocomial bacterial pathogen can be associated with life-threatening infections, particularly in intensive care units. A. baumannii is mainly described as an extracellular pathogen with restricted survival within cells. This study shows that a subset of A. baumannii clinical isolates extensively multiply within nonphagocytic immortalized and primary cells without the induction of apoptosis and with bacterial clusters visible up to 48 h after infection. This phenotype was observed for the A. baumannii C4 strain associated with high mortality in a hospital outbreak and the A. baumannii ABC141 strain, which was isolated from the skin but was found to be hyperinvasive. Intracellular multiplication of these A. baumannii strains occurred within spacious single membrane-bound vacuoles, labeled with the lysosomal associate membrane protein (LAMP1). However, these compartments excluded lysotracker, an indicator of acidic pH, suggesting that A. baumannii can divert its trafficking away from the lysosomal degradative pathway. These compartments were also devoid of autophagy features. A high-content microscopy screen of 43 additional A. baumannii clinical isolates highlighted various phenotypes, and (i) the majority of isolates remained extracellular, (ii) a significant proportion was capable of invasion and limited persistence, and (iii) three more isolates efficiently multiplied within LAMP1-positive vacuoles, one of which was also hyperinvasive. These data identify an intracellular niche for specific A. baumannii clinical isolates that enables extensive multiplication in an environment protected from host immune responses and out of reach of many antibiotics. IMPORTANCE Multidrug-resistant Acinetobacter baumannii isolates are associated with significant morbidity and mortality in hospitals worldwide. Understanding their pathogenicity is critical for improving therapeutic management. Although A. baumannii can steadily adhere to surfaces and host cells, most bacteria remain extracellular. Recent studies have shown that a small proportion of bacteria can invade cells but present limited survival. We have found that some A. baumannii clinical isolates can establish a specialized intracellular niche that sustains extensive intracellular multiplication for a prolonged time without induction of cell death. We propose that this intracellular compartment allows A. baumannii to escape the cell’s normal degradative pathway, protecting bacteria from host immune responses and potentially hindering antibiotic accessibility. This may contribute to A. baumannii persistence, relapsing infections, and enhanced mortality in susceptible patients. A high-content microscopy-based screen confirmed that this pathogenicity trait is present in other clinical A. baumannii isolates. There is an urgent need for new antibiotics or alternative antimicrobial approaches, particularly to combat carbapenem-resistant A. baumannii. The discovery of an intracellular niche for this pathogen, as well as hyperinvasive isolates, may help guide the development of antimicrobial therapies and diagnostics in the future.
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Tansho-Nagakawa S, Sato Y, Ubagai T, Kikuchi-Ueda T, Kamoshida GO, Nishida S, Ono Y. Histopathological Analysis of Acinetobacter baumannii Lung Infection in a Mouse Model. Pol J Microbiol 2022; 70:469-477. [PMID: 35003278 PMCID: PMC8702610 DOI: 10.33073/pjm-2021-044] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 10/31/2021] [Indexed: 11/20/2022] Open
Abstract
Acinetobacter baumannii is the main causative pathogen of nosocomial infections that causes severe infections in the lungs. In this study, we analyzed the histopathological characteristics of lung infection with two strains of A. baumannii (ATCC 19606 and the clinical isolate TK1090) and Pseudomonas aeruginosa PAO-1 in C3H/HeN mice to evaluate the virulence of A. baumannii. Survival was evaluated over 14 days. At 1, 2, 5, or 14 days postinfection, mice of C3H/HeN were sacrificed, and histopathological analysis of lung specimens was also performed. Histopathological changes and accumulation of neutrophils and macrophages in the lungs after infection with A. baumannii and P. aeruginosa were analyzed. Following intratracheal inoculation, the lethality of ATCC 19606- and TK1090-infected mice was lower than that of PAO-1-infected mice. However, when mice were inoculated with a sub-lethal dose of A. baumannii, the lung bacterial burden remained in the mice until 14 days post-infection. Additionally, histopathological analysis revealed that macrophages infiltrated the lung foci of ATCC 19606-, TK1090-, and PAO-1-infected mice. Although neutrophils infiltrated the lung foci of ATCC 19606- and TK1090-infected mice, they poorly infiltrated the lung foci of PAO-1-infected mice. Accumulation of these cells in the lung foci of ATCC 19606- and TK1090-infected mice, but not PAO-1-infected mice, was observed for 14 days post-infection. These results suggest that A. baumannii is not completely eliminated despite the infiltration of immune cells in the lungs and that inflammation lasts for prolonged periods in the lungs. Further studies are required to understand the mechanism of A. baumannii infection, and novel drugs and vaccines should be developed to prevent A. baumannii infection.
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Affiliation(s)
- Shigeru Tansho-Nagakawa
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan
| | - Yoshinori Sato
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan
| | - Tsuneyuki Ubagai
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan
| | - Takane Kikuchi-Ueda
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan
| | - G O Kamoshida
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan
| | - Satoshi Nishida
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan
| | - Yasuo Ono
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan
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21
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Akhova A, Nesterova L, Shumkov M, Tkachenko A. Cadaverine biosynthesis contributes to decreased Escherichia coli susceptibility to antibiotics. Res Microbiol 2021; 172:103881. [PMID: 34543694 DOI: 10.1016/j.resmic.2021.103881] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 09/09/2021] [Accepted: 09/09/2021] [Indexed: 12/24/2022]
Abstract
Some bacterial stress responses are involved in survival under antibiotic treatment and contribute to less susceptible microbial forms selection. Here, we tested the role of cadaverine, one of the biogenic polyamines considered as universal adaptogens, in the processes. The expression of ldcC and cadA genes, encoding cadaverine-producing lysine decarboxylase, increased in Escherichia coli cells exposed to β-lactams and fluoroquinolones but not aminoglycosides. The transcriptional regulators RpoS and SoxS controlled the expression of ldcC and cadA, respectively, in response to antibiotics. Exogenous cadaverine had little effect on E. coli antibiotic susceptibility, whereas non-antibiotic-induced endogenous cadaverine contributed to its tolerance to β-lactams, fluoroquinolones, and aminoglycosides. Antibiotic-induced cadaverine synthesis promoted bacterial survival under fluoroquinolone exposure, as well as could contribute to low-resistant bacterial forms development. Selection under the fluoroquinolone levofloxacin exposure toward bacteria with an increased ability to synthesize cadaverine and negative correlation between LdcC activity and fluoroquinolone susceptibility in the selected forms were demonstrated. The same correlation in a special group of low-level resistant clinical E. coli isolates was revealed. So, cadaverine biosynthesis appeared to be a significant player in decreased E. coli antibiotic susceptibility development.
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Affiliation(s)
- Anna Akhova
- Laboratory of Microbial Adaptation, Institute of Ecology and Genetics of Microorganisms, Perm Federal Research Center of the Ural Brunch of the Russian Academy of Sciences, 13, Golev st, Perm, 614081, Russia; Perm State University, 15, Bukirev st, 614068, Perm, Russia.
| | - Larisa Nesterova
- Laboratory of Microbial Adaptation, Institute of Ecology and Genetics of Microorganisms, Perm Federal Research Center of the Ural Brunch of the Russian Academy of Sciences, 13, Golev st, Perm, 614081, Russia; Perm State University, 15, Bukirev st, 614068, Perm, Russia.
| | - Mikhail Shumkov
- Group of Microbial Genomes Editing, Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, 33, Leninsky prospect, 119071, Moscow, Russia.
| | - Alexander Tkachenko
- Laboratory of Microbial Adaptation, Institute of Ecology and Genetics of Microorganisms, Perm Federal Research Center of the Ural Brunch of the Russian Academy of Sciences, 13, Golev st, Perm, 614081, Russia; Perm State University, 15, Bukirev st, 614068, Perm, Russia.
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22
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Rajapaksha DC, Jayathilaka EHTT, Edirisinghe SL, Nikapitiya C, Lee J, Whang I, De Zoysa M. Octopromycin: Antibacterial and antibiofilm functions of a novel peptide derived from Octopus minor against multidrug-resistant Acinetobacter baumannii. FISH & SHELLFISH IMMUNOLOGY 2021; 117:82-94. [PMID: 34311097 DOI: 10.1016/j.fsi.2021.07.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Revised: 06/28/2021] [Accepted: 07/22/2021] [Indexed: 06/13/2023]
Abstract
The emergence of carbapenem-resistant Acinetobacter baumannii has increased the risk of nosocomial infections, which pose a huge health threat. There is an urgent need to develop alternative therapies, including broad-spectrum antimicrobial peptides. In this study, we designed, characterized, and studied the antibacterial, antibiofilm effects and possible mode of actions of a novel synthetic peptide Octopromycin, derived from the proline-rich protein 5 of Octopus minor. Octopromycin consists of 38 amino acids, (+5) net positive charge, high hydrophobic residue ratio (36%), and two α-helix secondary structures. The minimum inhibitory concentration and minimum bactericidal concentration against A. baumannii were 50 and 200 μg/mL, respectively. Time-kill kinetics and bacterial viability assays confirmed the concentration-dependent antibacterial activity of Octopromycin. Field emission scanning electron microscopy images clearly showed ultrastructural alterations in Octopromycin-treated A. baumannii cells. Propidium iodide penetrated into Octopromycin-treated A. baumannii cells, demonstrating the loss of cell membrane integrity. Octopromycin treatment increased the production of reactive oxygen species in a concentration-dependent manner, and it inhibited the biofilm formation and showed biofilm eradication activity against A. baumannii. In vitro and in vivo safety evaluation revealed that Octopromycin was nontoxic to HEK293T and Raw 264.7 cells (<400 μg/mL), as well as mice red blood cells (<300 μg/mL), and zebrafish embryos (<4 μg/mL). An in vivo study results revealed that the A. baumannii-infected fish treated with Octopromycin exhibited a significantly higher relative percent survival (37.5%) than the infected mock-treated fish with PBS (16.6%). Furthermore, a decreased bacterial load and fewer alterations in histological analysis confirmed the successful control of A. baumannii by Octopromycin in vivo. Collectively, the results indicate that the antibacterial peptide Octopromycin may achieve rapid control of A. baumannii through multi-target interactions; it presents a desirable therapeutic option for the prevention and control of the infections.
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Affiliation(s)
- D C Rajapaksha
- College of Veterinary Medicine, Chungnam National University, Yuseong-gu, Daejeon, 34134, Republic of Korea
| | - E H T Thulshan Jayathilaka
- College of Veterinary Medicine, Chungnam National University, Yuseong-gu, Daejeon, 34134, Republic of Korea
| | - S L Edirisinghe
- College of Veterinary Medicine, Chungnam National University, Yuseong-gu, Daejeon, 34134, Republic of Korea
| | - Chamilani Nikapitiya
- College of Veterinary Medicine, Chungnam National University, Yuseong-gu, Daejeon, 34134, Republic of Korea
| | - Joeun Lee
- National Marine Biodiversity Institute of Korea (MABIK), 75, Jangsan-ro 101beon-gil, Janghang-eup, Seochun-gun, Chungchungnam-do, 33662, Republic of Korea
| | - Ilson Whang
- National Marine Biodiversity Institute of Korea (MABIK), 75, Jangsan-ro 101beon-gil, Janghang-eup, Seochun-gun, Chungchungnam-do, 33662, Republic of Korea.
| | - Mahanama De Zoysa
- College of Veterinary Medicine, Chungnam National University, Yuseong-gu, Daejeon, 34134, Republic of Korea.
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23
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Non-Coding RNAs and Reactive Oxygen Species–Symmetric Players of the Pathogenesis Associated with Bacterial and Viral Infections. Symmetry (Basel) 2021. [DOI: 10.3390/sym13071307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Infections can be triggered by a wide range of pathogens. However, there are few strains of bacteria that cause illness, but some are quite life-threatening. Likewise, viral infections are responsible for many human diseases, usually characterized by high contagiousness. Hence, as bacterial and viral infections can both cause similar symptoms, it can be difficult to determine the exact cause of a specific infection, and this limitation is critical. However, recent scientific advances have geared us up with the proper tools required for better diagnoses. Recent discoveries have confirmed the involvement of non-coding RNAs (ncRNAs) in regulating the pathogenesis of certain bacterial or viral infections. Moreover, the presence of reactive oxygen species (ROS) is also known as a common infection trait that can be used to achieve a more complete description of such pathogen-driven conditions. Thus, this opens further research opportunities, allowing scientists to explore infection-associated genetic patterns and develop better diagnosis and treatment methods. Therefore, the aim of this review is to summarize the current knowledge of the implication of ncRNAs and ROS in bacterial and viral infections, with great emphasis on their symmetry but, also, on their main differences.
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24
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Mayura IPB, Gotoh K, Nishimura H, Nakai E, Mima T, Yamamoto Y, Yokota K, Matsushita O. Elizabethkingia anophelis, an emerging pathogen, inhibits RAW 264.7 macrophage function. Microbiol Immunol 2021; 65:317-324. [PMID: 33913521 DOI: 10.1111/1348-0421.12888] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 04/21/2021] [Accepted: 04/22/2021] [Indexed: 11/27/2022]
Abstract
Elizabethkingia anophelis is a pathogen that can cause a life-threatening infection in immunocompromised patients. The first case of E. anophelis infection was reported in 2013; subsequently, an increase in its incidence has been reported globally. Additionally, a mortality rate of more than 30% was observed in the US outbreak of 2015. To date, the pathogenic mechanisms underlying E. anophelis infection, such as toxin production, remain unclear. Since tissue macrophages act as the first line of defense against pathogens, in the present study the interactions between E. anophelis and a macrophage-like cell line RAW 264.7 were examined. Although E. anophelis showed no cytotoxicity toward RAW 264.7 macrophages, the infection inhibited LPS-induced morphological changes and activation of differentiation markers for the polarization of RAW 264.7 macrophages toward an M1-like phenotype. However, when the cell contact was restricted using Transwell inserts or bacterial culture supernatants were used instead of live bacteria, no such inhibition was observed. Moreover, it was shown that E. anophelis evaded phagocytosis. Overall, the results suggest that E. anophelis infection inhibits the differentiation of RAW 264.7 macrophages to a pro-inflammatory phenotype in a contact-dependent manner.
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Affiliation(s)
- I Putu Bayu Mayura
- Department of Bacteriology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.,Department of Clinical Microbiology, Faculty of Medicine, Udayana University, Bali, Indonesia
| | - Kazuyoshi Gotoh
- Department of Bacteriology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Hayato Nishimura
- Department of Bacteriology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Erina Nakai
- Department of Bacteriology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Takehiko Mima
- Department of Bacteriology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Yumiko Yamamoto
- Department of Bacteriology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Kenji Yokota
- Graduate School of Health Science, Okayama University, Okayama, Japan
| | - Osamu Matsushita
- Department of Bacteriology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
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25
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Li X, Liu X, Horvatovich P, Hu Y, Zhang J. Proteomics Landscape of Host-Pathogen Interaction in Acinetobacter baumannii Infected Mouse Lung. Front Genet 2021; 12:563516. [PMID: 34025711 PMCID: PMC8138179 DOI: 10.3389/fgene.2021.563516] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 04/14/2021] [Indexed: 12/15/2022] Open
Abstract
Acinetobacter baumannii is an important pathogen of nosocomial infection worldwide, which can primarily cause pneumonia, bloodstream infection, and urinary tract infection. The increasing drug resistance rate of A. baumannii and the slow development of new antibacterial drugs brought great challenges for clinical treatment. Host immunity is crucial to the defense of A. baumannii infection, and understanding the mechanisms of immune response can facilitate the development of new therapeutic strategies. To characterize the system-level changes of host proteome in immune response, we used tandem mass tag (TMT) labeling quantitative proteomics to compare the proteome changes of lungs from A. baumannii infected mice with control mice 6 h after infection. A total of 6,218 proteins were identified in which 6,172 could be quantified. With threshold p < 0.05 and relative expression fold change > 1.2 or < 0.83, we found 120 differentially expressed proteins. Bioinformatics analysis showed that differentially expressed proteins after infection were associated with receptor recognition, NADPH oxidase (NOX) activation and antimicrobial peptides. These differentially expressed proteins were involved in the pathways including leukocyte transendothelial migration, phagocyte, neutrophil degranulation, and antimicrobial peptides. In conclusion, our study showed proteome changes in mouse lung tissue due to A. baumannii infection and suggested the important roles of NOX, neutrophils, and antimicrobial peptides in host response. Our results provide a potential list of protein candidates for the further study of host-bacteria interaction in A. baumannii infection. Data are available via ProteomeXchange with identifier PXD020640.
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Affiliation(s)
- Xin Li
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China.,Key Laboratory of Clinical Pharmacology of Antibiotics, National Health and Family Planning Commission, Shanghai, China.,National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Xiaofen Liu
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China.,Key Laboratory of Clinical Pharmacology of Antibiotics, National Health and Family Planning Commission, Shanghai, China.,National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Peter Horvatovich
- Department of Analytical Biochemistry, Groningen Research Institute of Pharmacy, University of Groningen, Groningen, Netherlands
| | - Yingwei Hu
- Department of Pathology, Johns Hopkins University, Baltimore, MD, United States
| | - Jing Zhang
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China.,Key Laboratory of Clinical Pharmacology of Antibiotics, National Health and Family Planning Commission, Shanghai, China.,National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
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26
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Grier JT, Arivett BA, Ramírez MS, Chosed RJ, Bigner JA, Ohneck EJ, Metz ML, Wood CR, Arce S, Tartaro A, Relich RF, Actis LA, Fiester SE. Two Acinetobacter baumannii Isolates Obtained From a Fatal Necrotizing Fasciitis Infection Display Distinct Genomic and Phenotypic Characteristics in Comparison to Type Strains. Front Cell Infect Microbiol 2021; 11:635673. [PMID: 33912474 PMCID: PMC8072282 DOI: 10.3389/fcimb.2021.635673] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 03/11/2021] [Indexed: 11/23/2022] Open
Abstract
Acinetobacter baumannii has been recognized as a critical pathogen that causes severe infections worldwide not only because of the emergence of extensively drug-resistant (XDR) derivatives, but also because of its ability to persist in medical environments and colonize compromised patients. While there are numerous reports describing the mechanisms by which this pathogen acquires resistance genes, little is known regarding A. baumannii’s virulence functions associated with rare manifestations of infection such as necrotizing fasciitis, making the determination and implementation of alternative therapeutic targets problematic. To address this knowledge gap, this report describes the analysis of the NFAb-1 and NFAb-2 XDR isolates, which were obtained at two time points during a fatal case of necrotizing fasciitis, at the genomic and functional levels. The comparative genomic analysis of these isolates with the ATCC 19606T and ATCC 17978 strains showed that the NFAb-1 and NFAb-2 isolates are genetically different from each other as well as different from the ATCC 19606T and ATCC 17978 clinical isolates. These genomic differences could be reflected in phenotypic differences observed in these NFAb isolates. Biofilm, cell viability and flow cytometry assays indicate that all tested strains caused significant decreases in A549 human alveolar epithelial cell viability with ATCC 17978, NFAb-1 and NFAb-2 producing significantly less biofilm and significantly more hemolysis and capacity for intracellular invasion than ATCC 19606T. NFAb-1 and NFAb-2 also demonstrated negligible surface motility but significant twitching motility compared to ATCC 19606T and ATCC 17978, likely due to the presence of pili exceeding 2 µm in length, which are significantly longer and different from those previously described in the ATCC 19606T and ATCC 17978 strains. Interestingly, infection with cells of the NFAb-1 isolate, which were obtained from a premortem blood sample, lead to significantly higher mortality rates than NFAb-2 bacteria, which were obtained from postmortem tissue samples, when tested using the Galleria mellonella in vivo infection model. These observations suggest potential changes in the virulence phenotype of the A. baumannii necrotizing fasciitis isolates over the course of infection by mechanisms and cell processes that remain to be identified.
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Affiliation(s)
- Jennifer T Grier
- Department of Biomedical Sciences, University of South Carolina School of Medicine Greenville, Greenville, SC, United States
| | - Brock A Arivett
- Department of Biology, Middle Tennessee State University, Murfreesboro, TN, United States
| | - Maria S Ramírez
- Department of Biological Science, California State University Fullerton, Fullerton, CA, United States
| | - Renee J Chosed
- Department of Biomedical Sciences, University of South Carolina School of Medicine Greenville, Greenville, SC, United States
| | - Jessica A Bigner
- Department of Biomedical Sciences, University of South Carolina School of Medicine Greenville, Greenville, SC, United States
| | - Emily J Ohneck
- Department of Microbiology, Miami University, Oxford, OH, United States
| | - Maeva L Metz
- Department of Microbiology, Miami University, Oxford, OH, United States
| | - Cecily R Wood
- Department of Microbiology, Miami University, Oxford, OH, United States
| | - Sergio Arce
- Department of Biomedical Sciences, University of South Carolina School of Medicine Greenville, Greenville, SC, United States.,Cancer Institute, Prisma Health, Greenville, SC, United States
| | - Andrea Tartaro
- Computer Science Department, Furman University, Greenville, SC, United States
| | - Ryan F Relich
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Luis A Actis
- Department of Microbiology, Miami University, Oxford, OH, United States
| | - Steven E Fiester
- Department of Biomedical Sciences, University of South Carolina School of Medicine Greenville, Greenville, SC, United States.,Department of Pathology, Prisma Health, Greenville, SC, United States
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27
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Kannan S, Solomon A, Krishnamoorthy G, Marudhamuthu M. Liposome encapsulated surfactant abetted copper nanoparticles alleviates biofilm mediated virulence in pathogenic Pseudomonas aeruginosa and MRSA. Sci Rep 2021; 11:1102. [PMID: 33441765 PMCID: PMC7806599 DOI: 10.1038/s41598-020-79976-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 11/04/2020] [Indexed: 01/05/2023] Open
Abstract
In the present study lipopeptide biosurfactant with high emulsification capacity produced by human skin bacterium Paenibacillus thiaminolyticus was purified and subjected to FTIR and NMR spectral analysis which gave evidence of the active characteristics of the surfactant. To augment the antivirulent potential further, the mixer of copper and copper oxide nanoparticles (CuNPs) was synthesized, and characterized by UV–Visible spectroscopy, SEM-EDAX, TEM, and Zeta analysis. Here, we attempted to enhance the antimicrobial and antibiofilm activity with the assistance of encapsulated preparation of lipopeptide and CuNPs in multilamellar liposomes. The proposed mechanism of action of lipopeptide and CuNPs liposomal preparation negatively influences the cell metabolism, secreted virulence such as staphyloxanthin, pyocyanin, and extracellular polysaccharides. The significant decline in the growth of MRSA and P. aeruginosa in both planktonic form and biofilm by lipopeptide and CuNPs treatment were visualized using scanning electron microscopy and High content screening imaging system. In vivo studies revealed that treatment with lipopeptide and CuNPs in multilamellar liposomes extended the lifespan of infected Caenorhabditis elegans by about 75%. Therefore, this study typifies lipopeptide and CuNPs could credibly be a substantial substitute over conventional antibiotics in averting the biofilm associated pathogenesis of MRSA and P. aeruginosa.
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Affiliation(s)
- Suganya Kannan
- Department of Microbial Technology, School of Biological Sciences, Madurai Kamaraj University, Tamil Nadu, Madurai, 625021, India
| | - Anitta Solomon
- Department of Microbial Technology, School of Biological Sciences, Madurai Kamaraj University, Tamil Nadu, Madurai, 625021, India
| | - Govindan Krishnamoorthy
- Department of Microbial Technology, School of Biological Sciences, Madurai Kamaraj University, Tamil Nadu, Madurai, 625021, India
| | - Murugan Marudhamuthu
- Department of Microbial Technology, School of Biological Sciences, Madurai Kamaraj University, Tamil Nadu, Madurai, 625021, India.
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28
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Sato Y, Tansho-Nagakawa S, Ubagai T, Ono Y. Analysis of Immune Responses in Acinetobacter baumannii-Infected Klotho Knockout Mice: A Mouse Model of Acinetobacter baumannii Infection in Aged Hosts. Front Immunol 2020; 11:601614. [PMID: 33329595 PMCID: PMC7719750 DOI: 10.3389/fimmu.2020.601614] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 10/27/2020] [Indexed: 12/24/2022] Open
Abstract
Acinetobacter baumannii is an important opportunistic pathogen that primarily afflicts elderly people. To clarify the pathogenicity of A. baumannii in the elderly, we investigated immune responses to A. baumannii ATCC 19606 infection in klotho knockout (KO) mice, the mouse model of aging. Following intravenous inoculation, the mice seldom displayed severe symptoms. However, the survival rate was 56% at 7 days post-infection. Bacteria were detected in the lungs of klotho KO mice but not klotho wildtype (WT) mice at 7 days post-infection. Neutrophils, eosinophils, interstitial macrophages, and monocyte/dendritic cell subset in the lungs of klotho KO mice were transiently induced after infection with A. baumannii. The number of alveolar macrophages in klotho KO mice was lower than that in klotho WT mice, except for 1 day post-infection. CD11b expression on neutrophils and alveolar macrophages in the lungs of klotho KO mice was seldom upregulated by the infection. These results suggested that immune functions eliminating bacteria in the lungs of klotho KO mice were insufficient. CD11blow conventional DC cells hardly increased in klotho KO mice infected with A. baumannii. Additionally, the production of interleukin (IL)-10 in the sera of klotho KO mice was significantly higher than that in klotho WT mice, whereas that production of interferon-gamma was not detected in the sera of klotho KO mice. These results suggested that acquired immune responses were hardly induced in klotho KO mice. IL-1β, CXCL1, CXCL2, and CCL2 expression was significantly higher in the lungs of klotho KO mice infected with A. baumannii than in those of klotho WT mice at 1 day post-infection. These results suggested that pulmonary inflammation was elicited in klotho KO mice during early infection. The expression levels of proinflammatory cytokines significantly correlated with TLR9 expression in the lungs of klotho KO mice. The collective results demonstrate an A. baumannii infection state in aged hosts and suggest that pulmonary inflammation and bacterial burden should be noted in aged hosts even in the absence of severe symptoms of A. baumannii infection.
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Affiliation(s)
- Yoshinori Sato
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan
| | - Shigeru Tansho-Nagakawa
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan
| | - Tsuneyuki Ubagai
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan
| | - Yasuo Ono
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan
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29
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Chen W. Host Innate Immune Responses to Acinetobacter baumannii Infection. Front Cell Infect Microbiol 2020; 10:486. [PMID: 33042864 PMCID: PMC7521131 DOI: 10.3389/fcimb.2020.00486] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Accepted: 08/05/2020] [Indexed: 12/23/2022] Open
Abstract
Acinetobacter baumannii has emerged as a major threat to global public health and is one of the key human pathogens in healthcare (nosocomial and community-acquired)-associated infections. Moreover, A. baumannii rapidly develops resistance to multiple antibiotics and is now globally regarded as a serious multidrug resistant pathogen. There is an urgent need to develop novel vaccines and immunotherapeutics as alternatives to antibiotics for clinical management of A. baumannii infection. However, our knowledge of host immune responses to A. baumannii infection and the identification of novel therapeutic targets are significantly lacking. This review highlights the recent advances and critical gaps in our understanding how A. baumannii interacts with the host innate pattern-recognition receptors, induces a cascade of inflammatory cytokine and chemokine responses, and recruits innate immune effectors (such as neutrophils and macrophages) to the site of infection for effective control of the infection. Such knowledge will facilitate the identification of new targets for the design and development of effective therapeutics and vaccines to fight this emerging threat.
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Affiliation(s)
- Wangxue Chen
- Human Health and Therapeutics (HHT) Research Center, National Research Council Canada, Ottawa, ON, Canada.,Department of Biology, Brock University, St. Catharines, ON, Canada
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30
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Bekeredjian-Ding I. Challenges for Clinical Development of Vaccines for Prevention of Hospital-Acquired Bacterial Infections. Front Immunol 2020; 11:1755. [PMID: 32849627 PMCID: PMC7419648 DOI: 10.3389/fimmu.2020.01755] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Accepted: 06/30/2020] [Indexed: 12/19/2022] Open
Abstract
Increasing antibiotic resistance in bacteria causing endogenous infections has entailed a need for innovative approaches to therapy and prophylaxis of these infections and raised a new interest in vaccines for prevention of colonization and infection by typically antibiotic resistant pathogens. Nevertheless, there has been a long history of failures in late stage clinical development of this type of vaccines, which remains not fully understood. This article provides an overview on present and past vaccine developments targeting nosocomial bacterial pathogens; it further highlights the specific challenges associated with demonstrating clinical efficacy of these vaccines and the facts to be considered in future study designs. Notably, these vaccines are mainly applied to subjects with preexistent immunity to the target pathogen, transient or chronic immunosuppression and ill-defined microbiome status. Unpredictable attack rates and changing epidemiology as well as highly variable genetic and immunological strain characteristics complicate the development. In views of the clinical need, re-thinking of the study designs and expectations seems warranted: first of all, vaccine development needs to be footed on a clear rationale for choosing the immunological mechanism of action and the optimal time point for vaccination, e.g., (1) prevention (or reduction) of colonization vs. prevention of infection and (2) boosting of a preexistent immune response vs. altering the quality of the immune response. Furthermore, there are different, probably redundant, immunological and microbiological defense mechanisms that provide protection from infection. Their interplay is not well-understood but as a consequence their effect might superimpose vaccine-mediated resolution of infection and lead to failure to demonstrate efficacy. This implies that improved characterization of patient subpopulations within the trial population should be obtained by pro- and retrospective analyses of trial data on subject level. Statistical and systems biology approaches could help to define immune and microbiological biomarkers that discern populations that benefit from vaccination from those where vaccines might not be effective.
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Affiliation(s)
- Isabelle Bekeredjian-Ding
- Division of Microbiology, Langen, Germany.,Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
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31
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Monem S, Furmanek-Blaszk B, Łupkowska A, Kuczyńska-Wiśnik D, Stojowska-Swędrzyńska K, Laskowska E. Mechanisms Protecting Acinetobacter baumannii against Multiple Stresses Triggered by the Host Immune Response, Antibiotics and Outside-Host Environment. Int J Mol Sci 2020; 21:E5498. [PMID: 32752093 PMCID: PMC7432025 DOI: 10.3390/ijms21155498] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 07/29/2020] [Accepted: 07/30/2020] [Indexed: 02/06/2023] Open
Abstract
Acinetobacter baumannii is considered one of the most persistent pathogens responsible for nosocomial infections. Due to the emergence of multidrug resistant strains, as well as high morbidity and mortality caused by this pathogen, A. baumannii was placed on the World Health Organization (WHO) drug-resistant bacteria and antimicrobial resistance research priority list. This review summarizes current studies on mechanisms that protect A. baumannii against multiple stresses caused by the host immune response, outside host environment, and antibiotic treatment. We particularly focus on the ability of A. baumannii to survive long-term desiccation on abiotic surfaces and the population heterogeneity in A. baumannii biofilms. Insight into these protective mechanisms may provide clues for the development of new strategies to fight multidrug resistant strains of A. baumannii.
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Affiliation(s)
- Soroosh Monem
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland; (S.M.); (A.Ł.); (D.K.-W.); (K.S.-S.)
| | - Beata Furmanek-Blaszk
- Department of Microbiology, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland;
| | - Adrianna Łupkowska
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland; (S.M.); (A.Ł.); (D.K.-W.); (K.S.-S.)
| | - Dorota Kuczyńska-Wiśnik
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland; (S.M.); (A.Ł.); (D.K.-W.); (K.S.-S.)
| | - Karolina Stojowska-Swędrzyńska
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland; (S.M.); (A.Ł.); (D.K.-W.); (K.S.-S.)
| | - Ewa Laskowska
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland; (S.M.); (A.Ł.); (D.K.-W.); (K.S.-S.)
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32
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Acinetobacter baumannii NCIMB8209: a Rare Environmental Strain Displaying Extensive Insertion Sequence-Mediated Genome Remodeling Resulting in the Loss of Exposed Cell Structures and Defensive Mechanisms. mSphere 2020; 5:5/4/e00404-20. [PMID: 32727858 PMCID: PMC7392541 DOI: 10.1128/msphere.00404-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Acinetobacter baumannii is an ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) opportunistic pathogen, with poorly defined natural habitats/reservoirs outside the clinical setting. A. baumannii arose from the Acinetobacter calcoaceticus-A. baumannii complex as the result of a population bottleneck, followed by a recent population expansion from a few clinically relevant clones endowed with an arsenal of resistance and virulence genes. Still, the identification of virulence traits and the evolutionary paths leading to a pathogenic lifestyle has remained elusive, and thus, the study of nonclinical (“environmental”) A. baumannii isolates is necessary. We conducted here comparative genomic and virulence studies on A. baumannii NCMBI8209 isolated in 1943 from the microbiota responsible for the decomposition of guayule, and therefore well differentiated both temporally and epidemiologically from the multidrug-resistant strains that are predominant nowadays. Our work provides insights on the adaptive strategies used by A. baumannii to escape from host defenses and may help the adoption of measures aimed to limit its further dissemination. Acinetobacter baumannii represents nowadays an important nosocomial pathogen of poorly defined reservoirs outside the clinical setting. Here, we conducted whole-genome sequencing analysis of the Acinetobacter sp. NCIMB8209 collection strain, isolated in 1943 from the aerobic degradation (retting) of desert guayule shrubs. Strain NCIMB8209 contained a 3.75-Mb chromosome and a plasmid of 134 kb. Phylogenetic analysis based on core genes indicated NCIMB8209 affiliation to A. baumannii, a result supported by the identification of a chromosomal blaOXA-51-like gene. Seven genomic islands lacking antimicrobial resistance determinants, 5 regions encompassing phage-related genes, and notably, 93 insertion sequences (IS) were found in this genome. NCIMB8209 harbors most genes linked to persistence and virulence described in contemporary A. baumannii clinical strains, but many of the genes encoding components of surface structures are interrupted by IS. Moreover, defense genetic islands against biological aggressors such as type 6 secretion systems or CRISPR-cas are absent from this genome. These findings correlate with a low capacity of NCIMB8209 to form biofilm and pellicle, low motility on semisolid medium, and low virulence toward Galleria mellonella and Caenorhabditis elegans. Searching for catabolic genes and concomitant metabolic assays revealed the ability of NCIMB8209 to grow on a wide range of substances produced by plants, including aromatic acids and defense compounds against external aggressors. All the above features strongly suggest that NCIMB8209 has evolved specific adaptive features to a particular environmental niche. Moreover, they also revealed that the remarkable genetic plasticity identified in contemporary A. baumannii clinical strains represents an intrinsic characteristic of the species. IMPORTANCEAcinetobacter baumannii is an ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) opportunistic pathogen, with poorly defined natural habitats/reservoirs outside the clinical setting. A. baumannii arose from the Acinetobacter calcoaceticus-A. baumannii complex as the result of a population bottleneck, followed by a recent population expansion from a few clinically relevant clones endowed with an arsenal of resistance and virulence genes. Still, the identification of virulence traits and the evolutionary paths leading to a pathogenic lifestyle has remained elusive, and thus, the study of nonclinical (“environmental”) A. baumannii isolates is necessary. We conducted here comparative genomic and virulence studies on A. baumannii NCMBI8209 isolated in 1943 from the microbiota responsible for the decomposition of guayule, and therefore well differentiated both temporally and epidemiologically from the multidrug-resistant strains that are predominant nowadays. Our work provides insights on the adaptive strategies used by A. baumannii to escape from host defenses and may help the adoption of measures aimed to limit its further dissemination.
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Khoshnood S, Savari M, Abbasi Montazeri E, Farajzadeh Sheikh A. Survey on Genetic Diversity, Biofilm Formation, and Detection of Colistin Resistance Genes in Clinical Isolates of Acinetobacter baumannii. Infect Drug Resist 2020; 13:1547-1558. [PMID: 32547124 PMCID: PMC7266307 DOI: 10.2147/idr.s253440] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Introduction Acinetobacter baumannii is an opportunistic pathogen responsible for nosocomial infections. The emergence of colistin-resistant A. baumannii is a significant threat to public health. The aim of this study was to investigate the molecular characterization and genotyping of clinical A. baumannii isolates in Southwestern Iran. Methods A total of 70 A. baumannii isolates were collected from patients admitted to Imam Khomeini Hospital in Ahvaz, Southwestern Iran. Minimum inhibitory concentration test was conducted by using Vitek 2 system. The presence of biofilm-forming genes and colistin resistance-related genes were evaluated by PCR. The isolates were also examined for their biofilm formation ability and the expression of pmrA and pmrB genes. Finally, multilocus sequence typing (MLST) and PCR-based sequence group were used to determine the genetic relationships of the isolates. Results Overall, 61 (87.1%) and 9 (12.8%) isolates were multidrug-resistant (MDR) and extensively drug-resistant (XDR), respectively. Colistin and tigecycline with 2 (2.8%) and 32 (45.7%) resistance rates had the highest effect. Among all the isolates, 55 (78.5%), 7 (10%), and 3 (4.3%) were strong, moderate, and weak biofilm producers, respectively. The frequency rates of biofilm-related genes were 64 (91.4%), 70 (100%), 56 (80%), and 22 (31.42%) for bap, ompA, csuE, and blaPER1, respectively. Overexpression of pmrA and pmrB genes was observed in two colistin-resistance isolates, but the expression of these genes did not change in colistin-sensitive isolates. Additionally, 37 (52.8%) and 8 (11.4%) isolates belonged to groups 1 (ICII) and 2 (IC I), respectively. MLST analysis revealed a total of nine different sequence types that six isolates belonged to clonal complex 92 (corresponding to ST801, ST118, ST138, ST 421, and ST735). Other isolates were belonging to ST133 and ST216, and two colistin-resistant (Ab4 and Ab41) isolates were belonging to ST387 and ST1812. Conclusion The present study revealed the presence of MDR and XDR A. baumannii isolates harboring biofilm genes and emergence of colistin-resistant isolates in Southwestern Iran. These isolates had high diversity, which was affirmed by typing techniques. The control measures and regular surveillance are urgently needed to preclude the spread of these isolates.
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Affiliation(s)
- Saeed Khoshnood
- Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.,Department of Microbiology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Mohammad Savari
- Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.,Department of Microbiology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Effat Abbasi Montazeri
- Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.,Department of Microbiology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Ahmad Farajzadeh Sheikh
- Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.,Department of Microbiology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
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