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Lê-Bury P, Echenique-Rivera H, Pizarro-Cerdá J, Dussurget O. Determinants of bacterial survival and proliferation in blood. FEMS Microbiol Rev 2024; 48:fuae013. [PMID: 38734892 PMCID: PMC11163986 DOI: 10.1093/femsre/fuae013] [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: 11/06/2023] [Revised: 04/29/2024] [Accepted: 05/10/2024] [Indexed: 05/13/2024] Open
Abstract
Bloodstream infection is a major public health concern associated with high mortality and high healthcare costs worldwide. Bacteremia can trigger fatal sepsis whose prevention, diagnosis, and management have been recognized as a global health priority by the World Health Organization. Additionally, infection control is increasingly threatened by antimicrobial resistance, which is the focus of global action plans in the framework of a One Health response. In-depth knowledge of the infection process is needed to develop efficient preventive and therapeutic measures. The pathogenesis of bloodstream infection is a dynamic process resulting from the invasion of the vascular system by bacteria, which finely regulate their metabolic pathways and virulence factors to overcome the blood immune defenses and proliferate. In this review, we highlight our current understanding of determinants of bacterial survival and proliferation in the bloodstream and discuss their interactions with the molecular and cellular components of blood.
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Affiliation(s)
- Pierre Lê-Bury
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Yersinia Research Unit, 28 rue du Dr Roux, 75015 Paris, France
- Université Paris-Saclay, Inserm, CEA, Center for Immunology of Viral, Autoimmune, Hematological and Bacterial Diseases (IMVA-HB/IDMIT), 18 route du Panorama, 92260 Fontenay-aux-Roses, France
| | - Hebert Echenique-Rivera
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Yersinia Research Unit, 28 rue du Dr Roux, 75015 Paris, France
| | - Javier Pizarro-Cerdá
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Yersinia Research Unit, 28 rue du Dr Roux, 75015 Paris, France
- Institut Pasteur, Université Paris Cité, Yersinia National Reference Laboratory, WHO Collaborating Research & Reference Centre for Plague FRA-146, 28 rue du Dr Roux, 75015 Paris, France
| | - Olivier Dussurget
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Yersinia Research Unit, 28 rue du Dr Roux, 75015 Paris, France
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2
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Gao S, Jin W, Quan Y, Li Y, Shen Y, Yuan S, Yi L, Wang Y, Wang Y. Bacterial capsules: Occurrence, mechanism, and function. NPJ Biofilms Microbiomes 2024; 10:21. [PMID: 38480745 PMCID: PMC10937973 DOI: 10.1038/s41522-024-00497-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 03/05/2024] [Indexed: 03/17/2024] Open
Abstract
In environments characterized by extended multi-stress conditions, pathogens develop a variety of immune escape mechanisms to enhance their ability to infect the host. The capsules, polymers that bacteria secrete near their cell wall, participates in numerous bacterial life processes and plays a crucial role in resisting host immune attacks and adapting to their niche. Here, we discuss the relationship between capsules and bacterial virulence, summarizing the molecular mechanisms of capsular regulation and pathogenesis to provide new insights into the research on the pathogenesis of pathogenic bacteria.
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Affiliation(s)
- Shuji Gao
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
| | - Wenjie Jin
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
| | - Yingying Quan
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
| | - Yue Li
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
| | - Yamin Shen
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
| | - Shuo Yuan
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
| | - Li Yi
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
- College of Life Science, Luoyang Normal University, Luoyang, 471934, China
| | - Yuxin Wang
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China.
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China.
| | - Yang Wang
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China.
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China.
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3
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Tang M, Zhao D, Zhang Y, Qian C, Chen H, Chen L, Ye J, Zhou T. Impact of LuxS on virulence and pathogenicity in Klebsiella pneumoniae exhibiting varied mucoid phenotypes. Infect Immun 2024; 92:e0001224. [PMID: 38358274 DOI: 10.1128/iai.00012-24] [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: 01/11/2024] [Accepted: 01/17/2024] [Indexed: 02/16/2024] Open
Abstract
How the LuxS/AI-2 quorum sensing (QS) system influences the pathogenicity of K. pneumoniae is complicated by the heterogeneity of the bacterial mucoid phenotypes. This study aims to explore the LuxS-mediated regulation of the pathogenicity of K. pneumoniae with diverse mucoid phenotypes, including hypermucoid, regular-mucoid, and nonmucoid. The wild-type, luxS knockout, and complemented strains of three K. pneumoniae clinical isolates with distinct mucoid phenotypes were constructed. The results revealed the downregulation of virulence genes of regular-mucoid, and nonmucoid but not hypermucoid strains. The deletion of luxS reduced the pathogenicity of the regular-mucoid, and nonmucoid strains in mice; while in hypermucoid strain, luxS knockout reduced virulence in late growth but enhanced virulence in the early growth phase. Furthermore, the absence of luxS led the regular-mucoid and nonmucoid strains to be more sensitive to the host cell defense, and less biofilm-productive than the wild-type at both the low and high-density growth state. Nevertheless, luxS knockout enhanced the resistances to adhesion and phagocytosis by macrophage as well as serum-killing, of hypermucoid K. pneumoniae at its early low-density growth state, while it was opposite to those in its late high-density growth phase. Collectively, our results suggested that LuxS plays a crucial role in the pathogenicity of K. pneumoniae, and it is highly relevant to the mucoid phenotypes and growth phases of the strains. LuxS probably depresses the capsule in the early low-density phase and promotes the capsule, biofilm, and pathogenicity during the late high-density phase, but inhibits lipopolysaccharide throughout the growth phase, in K. pneumoniae.IMPORTANCECharacterizing the regulation of physiological functions by the LuxS/AI-2 quorum sensing (QS) system in Klebsiella pneumoniae strains will improve our understanding of this important pathogen. The genetic heterogeneity of K. pneumoniae isolates complicates our understanding of its pathogenicity, and the association of LuxS with bacterial pathogenicity has remained poorly addressed in K. pneumoniae. Our results demonstrated strain and growth phase-dependent variation in the contributions of LuxS to the virulence and pathogenicity of K. pneumoniae. Our findings provide new insights into the important contribution of the LuxS/AI-2 QS system to the networks that regulate the pathogenicity of K. pneumoniae. Our study will facilitate our understanding of the regulatory mechanisms of LuxS/AI-2 QS on the pathogenicity of K. pneumoniae under the background of their genetic heterogeneity and help develop new strategies for diminished bacterial virulence within the clinical K. pneumoniae population.
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Affiliation(s)
- Miran Tang
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Deyi Zhao
- Department of Medical Lab Science, School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Ying Zhang
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Changrui Qian
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Huale Chen
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Lijiang Chen
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jianzhong Ye
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Tieli Zhou
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
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Rodríguez-Medina N, Rodríguez-Santiago J, Alvarado-Delgado A, Sagal-Prado A, Silva-Sánchez J, De la Cruz MA, Ares MA, Sánchez-Arias M, Morfín-Otero R, Hernández-Castro R, Cornejo-Juárez P, Jiménez-Villanueva E, Sánchez-Francia D, Garza-Ramos U. Comprehensive study reveals phenotypic heterogeneity in Klebsiella pneumoniae species complex isolates. Sci Rep 2024; 14:5876. [PMID: 38467675 PMCID: PMC10928225 DOI: 10.1038/s41598-024-55546-z] [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: 10/31/2023] [Accepted: 02/25/2024] [Indexed: 03/13/2024] Open
Abstract
Here, we conducted a comprehensive analysis of 356 Klebsiella pneumoniae species complex (KpSC) isolates that were classified as classical (cl), presumptive hypervirulent (p-hv) and hypermucoviscous-like (hmv-like). Overall, K. pneumoniae (82.3%), K. variicola (2.5%) and K. quasipneumoniae (2.5%) were identified. These isolates comprised 321 cl-KpSC, 7 p-hv-KpSC and 18 hmv-like-KpSC. A large proportion of cl-KpSC isolates were extended-spectrum-β-lactamases (ESBLs)-producers (64.4%) and 3.4% of isolates were colistin-resistant carrying carbapenemase and ESBL genes. All p-hv-KpSC showed an antibiotic susceptible phenotype and hmv-like isolates were found to be ESBL-producers (8/18). Assays for capsule production and capsule-dependent virulence phenotypes and whole-genome sequencing (WGS) were performed in a subset of isolates. Capsule amount differed in all p-hv strains and hmv-like produced higher capsule amounts than cl strains; these variations had important implications in phagocytosis and virulence. Murine sepsis model showed that most cl strains were nonlethal and the hmv-like caused 100% mortality with 3 × 108 CFUs. Unexpectedly, 3/7 (42.9%) of p-hv strains required 108 CFUs to cause 100% mortality (atypical hypervirulent), and 4/7 (57.1%) strains were considered truly hypervirulent (hv). Genomic analyses confirmed the diverse population, including isolates belonging to hv clonal groups (CG) CG23, CG86, CG380 and CG25 (this corresponded to the ST3999 a novel hv clone) and MDR clones such as CG258 and CG147 (ST392) among others. We noted that the hmv-like and hv-ST3999 isolates showed a close phylogenetic relationship with cl-MDR K. pneumoniae. The information collected here is important to understand the evolution of clinically important phenotypes such as hypervirulent and ESBL-producing-hypermucoviscous-like amongst the KpSC in Mexican healthcare settings. Likewise, this study shows that mgrB inactivation is the main mechanism of colistin resistance in K. pneumoniae isolates from Mexico.
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Affiliation(s)
- Nadia Rodríguez-Medina
- Centro de Investigación Sobre Enfermedades Infecciosas (CISEI), Laboratorio de Resistencia Bacteriana, Instituto Nacional de Salud Pública (INSP), Av. Universidad # 655, Col. Santa María Ahuacatitlán, C.P. 62100, Cuernavaca, Morelos, Mexico
| | - Jonathan Rodríguez-Santiago
- Centro de Investigación Sobre Enfermedades Infecciosas (CISEI), Laboratorio de Resistencia Bacteriana, Instituto Nacional de Salud Pública (INSP), Av. Universidad # 655, Col. Santa María Ahuacatitlán, C.P. 62100, Cuernavaca, Morelos, Mexico
| | - Alejandro Alvarado-Delgado
- Centro de Investigación Sobre Enfermedades Infecciosas (CISEI), Laboratorio de Resistencia Bacteriana, Instituto Nacional de Salud Pública (INSP), Av. Universidad # 655, Col. Santa María Ahuacatitlán, C.P. 62100, Cuernavaca, Morelos, Mexico
| | - Alan Sagal-Prado
- Centro de Investigación Sobre Enfermedades Infecciosas (CISEI), Laboratorio de Resistencia Bacteriana, Instituto Nacional de Salud Pública (INSP), Av. Universidad # 655, Col. Santa María Ahuacatitlán, C.P. 62100, Cuernavaca, Morelos, Mexico
| | - Jesús Silva-Sánchez
- Centro de Investigación Sobre Enfermedades Infecciosas (CISEI), Laboratorio de Resistencia Bacteriana, Instituto Nacional de Salud Pública (INSP), Av. Universidad # 655, Col. Santa María Ahuacatitlán, C.P. 62100, Cuernavaca, Morelos, Mexico
| | - Miguel A De la Cruz
- Facultad de Medicina, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
| | - Miguel Angel Ares
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City, Mexico
| | - Margarita Sánchez-Arias
- Centro de Investigación Sobre Enfermedades Infecciosas (CISEI), Laboratorio de Resistencia Bacteriana, Instituto Nacional de Salud Pública (INSP), Av. Universidad # 655, Col. Santa María Ahuacatitlán, C.P. 62100, Cuernavaca, Morelos, Mexico
| | - Rayo Morfín-Otero
- Hospital Civil de Guadalajara "Fray Antonio Alcalde", Instituto de Patología Infecciosa y Experimental, Universidad de Guadalajara, Guadalajara, Jalisco, Mexico
| | | | | | | | | | - Ulises Garza-Ramos
- Centro de Investigación Sobre Enfermedades Infecciosas (CISEI), Laboratorio de Resistencia Bacteriana, Instituto Nacional de Salud Pública (INSP), Av. Universidad # 655, Col. Santa María Ahuacatitlán, C.P. 62100, Cuernavaca, Morelos, Mexico.
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5
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Roach DJ, Sridhar S, Oliver E, Rao SR, Slater DM, Hwang W, Hutt Vater K, Dinesh A, Qadri F, Chisti MJ, Pierce VM, Turbett SE, Bhattacharyya RP, Worby CJ, Earl AM, LaRocque RC, Harris JB. Clinical and Genomic Characterization of a Cohort of Patients With Klebsiella pneumoniae Bloodstream Infection. Clin Infect Dis 2024; 78:31-39. [PMID: 37633257 PMCID: PMC10810715 DOI: 10.1093/cid/ciad507] [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: 06/14/2023] [Revised: 08/09/2023] [Accepted: 08/22/2023] [Indexed: 08/28/2023] Open
Abstract
BACKGROUND The clinical and microbial factors associated with Klebsiella pneumoniae bloodstream infections (BSIs) are not well characterized. Prior studies have focused on highly resistant or hypervirulent isolates, limiting our understanding of K. pneumoniae strains that commonly cause BSI. We performed a record review and whole-genome sequencing to investigate the clinical characteristics, bacterial diversity, determinants of antimicrobial resistance, and risk factors for in-hospital death in a cohort of patients with K. pneumoniae BSI. METHODS We identified 562 patients at Massachusetts General Hospital with K. pneumoniae BSIs between 2016 and 2022. We collected data on comorbid conditions, infection source, clinical outcomes, and antibiotic resistance and performed whole-genome sequencing on 108 sequential BSI isolates from 2021 to 2022. RESULTS Intra-abdominal infection was the most common source of infection accounting for 34% of all BSIs. A respiratory tract source accounted for 6% of BSIs but was associated with a higher in-hospital mortality rate (adjusted odds ratio, 5.4 [95% confidence interval, 2.2-12.8]; P < .001 for comparison with other sources). Resistance to the first antibiotic prescribed was also associated with a higher risk of death (adjusted odds ratio, 5.2 [95% confidence interval, 2.2-12.4]; P < .001). BSI isolates were genetically diverse, and no clusters of epidemiologically and genetically linked cases were observed. Virulence factors associated with invasiveness were observed at a low prevalence, although an unexpected association between O-antigen type and the source of infection was found. CONCLUSIONS These observations demonstrate the versatility of K. pneumoniae as an opportunistic pathogen and highlight the need for new approaches for surveillance and the rapid identification of patients with invasive antimicrobial-resistant K. pneumoniae infection.
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Affiliation(s)
- David J Roach
- The Broad Institute of MIT and Harvard, Boston, Massachusetts, USA
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, Massachusetts, USA
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Sushmita Sridhar
- The Broad Institute of MIT and Harvard, Boston, Massachusetts, USA
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Elizabeth Oliver
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Sowmya R Rao
- Department of Global Health, Boston University, Boston, Massachusetts, USA
| | - Damien M Slater
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Wontae Hwang
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Kian Hutt Vater
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Anupama Dinesh
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Firdausi Qadri
- Dhaka Hospital, International Centre for Diarrheal Disease Research, Bangladesh
| | - Mohammod J Chisti
- Dhaka Hospital, International Centre for Diarrheal Disease Research, Bangladesh
| | - Virginia M Pierce
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Sarah E Turbett
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Roby P Bhattacharyya
- The Broad Institute of MIT and Harvard, Boston, Massachusetts, USA
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Colin J Worby
- The Broad Institute of MIT and Harvard, Boston, Massachusetts, USA
| | - Ashlee M Earl
- The Broad Institute of MIT and Harvard, Boston, Massachusetts, USA
| | - Regina C LaRocque
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Jason B Harris
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
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6
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Bain W, Ahn B, Peñaloza HF, McElheny CL, Tolman N, van der Geest R, Gonzalez-Ferrer S, Chen N, An X, Hosuru R, Tabary M, Papke E, Kohli N, Farooq N, Bachman W, Olonisakin TF, Xiong Z, Griffith MP, Sullivan M, Franks J, Mustapha MM, Iovleva A, Suber T, Shanks RQ, Ferreira VP, Stolz DB, Van Tyne D, Doi Y, Lee JS. In vivo evolution of a Klebsiella pneumoniae capsule defect with wcaJ mutation promotes complement-mediated opsono-phagocytosis during recurrent infection. J Infect Dis 2024:jiae003. [PMID: 38271564 DOI: 10.1093/infdis/jiae003] [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: 09/19/2023] [Revised: 12/17/2023] [Accepted: 01/03/2024] [Indexed: 01/27/2024] Open
Abstract
BACKGROUND Klebsiella pneumoniae carbapenemase-producing K. pneumoniae (KPC-Kp) bloodstream infections are associated with high mortality. We studied clinical bloodstream KPC-Kp isolates to investigate mechanisms of resistance to complement, a key host defense against bloodstream infection. METHODS We tested growth of KPC-Kp isolates in human serum. In serial isolates from a single patient, we performed whole genome sequencing and tested for complement resistance and binding by mixing study, direct ELISA, flow cytometry, and electron microscopy. We utilized an isogenic deletion mutant in phagocytosis assays and an acute lung infection model. RESULTS We found serum resistance in 16 of 59 (27%) KPC-Kp clinical bloodstream isolates. In five genetically-related bloodstream isolates from a single patient, we noted a loss-of-function mutation in the capsule biosynthesis gene, wcaJ. Disruption of wcaJ was associated with decreased polysaccharide capsule, resistance to complement-mediated killing, and surprisingly, increased binding of complement proteins. Furthermore, an isogenic wcaJ deletion mutant exhibited increased opsono-phagocytosis in vitro and impaired in vivo control in the lung after airspace macrophage depletion in mice. CONCLUSIONS Loss of function in wcaJ led to increased complement resistance, complement binding, and opsono-phagocytosis, which may promote KPC-Kp persistence by enabling co-existence of increased bloodstream fitness and reduced tissue virulence.
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Affiliation(s)
- William Bain
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Veterans Health Administration Pittsburgh Healthcare System, Pittsburgh, PA, USA
| | - Brian Ahn
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Anschutz Medical Campus School of Medicine, Denver, CO, USA
| | - Hernán F Peñaloza
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Christi L McElheny
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Nathanial Tolman
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Rick van der Geest
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Shekina Gonzalez-Ferrer
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Nathalie Chen
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Xiaojing An
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Ria Hosuru
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Mohammadreza Tabary
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Erin Papke
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Naina Kohli
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Nauman Farooq
- Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - William Bachman
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Tolani F Olonisakin
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Zeyu Xiong
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Marissa P Griffith
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Mara Sullivan
- Center for Biologic Imaging, Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jonathan Franks
- Center for Biologic Imaging, Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Mustapha M Mustapha
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Alina Iovleva
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Tomeka Suber
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Robert Q Shanks
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Viviana P Ferreira
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, USA
| | - Donna B Stolz
- Center for Biologic Imaging, Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Daria Van Tyne
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Yohei Doi
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Janet S Lee
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Division of Pulmonary and Critical Care Medicine, Washington University in St. Louis, St. Louis, MO, USA
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7
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Vezina B, Watts SC, Hawkey J, Cooper HB, Judd LM, Jenney AWJ, Monk JM, Holt KE, Wyres KL. Bactabolize is a tool for high-throughput generation of bacterial strain-specific metabolic models. eLife 2023; 12:RP87406. [PMID: 37815531 PMCID: PMC10564454 DOI: 10.7554/elife.87406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/11/2023] Open
Abstract
Metabolic capacity can vary substantially within a bacterial species, leading to ecological niche separation, as well as differences in virulence and antimicrobial susceptibility. Genome-scale metabolic models are useful tools for studying the metabolic potential of individuals, and with the rapid expansion of genomic sequencing there is a wealth of data that can be leveraged for comparative analysis. However, there exist few tools to construct strain-specific metabolic models at scale. Here, we describe Bactabolize, a reference-based tool which rapidly produces strain-specific metabolic models and growth phenotype predictions. We describe a pan reference model for the priority antimicrobial-resistant pathogen, Klebsiella pneumoniae, and a quality control framework for using draft genome assemblies as input for Bactabolize. The Bactabolize-derived model for K. pneumoniae reference strain KPPR1 performed comparatively or better than currently available automated approaches CarveMe and gapseq across 507 substrate and 2317 knockout mutant growth predictions. Novel draft genomes passing our systematically defined quality control criteria resulted in models with a high degree of completeness (≥99% genes and reactions captured compared to models derived from matched complete genomes) and high accuracy (mean 0.97, n=10). We anticipate the tools and framework described herein will facilitate large-scale metabolic modelling analyses that broaden our understanding of diversity within bacterial species and inform novel control strategies for priority pathogens.
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Affiliation(s)
- Ben Vezina
- Department of Infectious Diseases, Central Clinical School, Monash UniversityMelbourneAustralia
| | - Stephen C Watts
- Department of Infectious Diseases, Central Clinical School, Monash UniversityMelbourneAustralia
| | - Jane Hawkey
- Department of Infectious Diseases, Central Clinical School, Monash UniversityMelbourneAustralia
| | - Helena B Cooper
- Department of Infectious Diseases, Central Clinical School, Monash UniversityMelbourneAustralia
| | - Louise M Judd
- Department of Infectious Diseases, Central Clinical School, Monash UniversityMelbourneAustralia
| | | | - Jonathan M Monk
- Department of Bioengineering, University of California, San DiegoSan DiegoUnited States
| | - Kathryn E Holt
- Department of Infectious Diseases, Central Clinical School, Monash UniversityMelbourneAustralia
- Department of Infection Biology, London School of Hygiene & Tropical MedicineLondonUnited Kingdom
| | - Kelly L Wyres
- Department of Infectious Diseases, Central Clinical School, Monash UniversityMelbourneAustralia
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8
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Tang M, Huang Z, Zhang X, Kong J, Zhou B, Han Y, Zhang Y, Chen L, Zhou T. Phage resistance formation and fitness costs of hypervirulent Klebsiella pneumoniae mediated by K2 capsule-specific phage and the corresponding mechanisms. Front Microbiol 2023; 14:1156292. [PMID: 37538841 PMCID: PMC10394836 DOI: 10.3389/fmicb.2023.1156292] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 07/04/2023] [Indexed: 08/05/2023] Open
Abstract
Introduction Phage is promising for the treatment of hypervirulent Klebsiella pneumoniae (hvKP) infections. Although phage resistance seems inevitable, we found that there still was optimization space in phage therapy for hvKP infection. Methods The clinical isolate K. pneumoniae FK1979 was used to recover the lysis phage ΦFK1979 from hospital sewage. Phage-resistant bacteria were obtained on LB agar and used to isolate phages from sewage. The plaque assay, transmission electron microscopy (TEM), multiplicity of infection test, one-step growth curve assay, and genome analysis were performed to characterize the phages. Colony morphology, precipitation test and scanning electron microscope were used to characterize the bacteria. The absorption test, spot test and efficiency of plating (EOP) assay were used to identify the sensitivity of bacteria to phages. Whole genome sequencing (WGS) was used to identify gene mutations of phage-resistant bacteria. The gene expression levels were detected by RT-qPCR. Genes knockout and complementation of the mutant genes were performed. The change of capsules was detected by capsule quantification and TEM. The growth kinetics, serum resistance, biofilm formation, adhesion and invasion to A549 and RAW 264.7 cells, as well as G. mellonella and mice infection models, were used to evaluate the fitness and virulence of bacteria. Results and discussion Here, we demonstrated that K2 capsule type sequence type 86 hvKP FK1979, one of the main pandemic lineages of hvKP with thick capsule, rapidly developed resistance to a K2-specific lysis phage ΦFK1979 which was well-studied in this work to possess polysaccharide depolymerase. The phage-resistant mutants showed a marked decrease in capsule expression. WGS revealed single nucleotide polymorphism (SNP) in genes encoding RfaH, galU, sugar glycosyltransferase, and polysaccharide deacetylase family protein in the mutants. RfaH and galU were further identified as being required for capsule production and phage sensitivity. Expressions of genes involved in the biosynthesis or regulation of capsule and/or lipopolysaccharide significantly decreased in the mutants. Despite the rapid and frequent development of phage resistance being a disadvantage, the attenuation of virulence and fitness in vitro and in vivo indicated that phage-resistant mutants of hvKP were more susceptible to the immunity system. Interestingly, the newly isolated phages targeting mutants changed significantly in their plaque and virus particle morphology. Their genomes were much larger than and significantly different from that of ΦFK1979. They possessed much more functional proteins and strikingly broader host spectrums than ΦFK1979. Our study suggests that K2-specific phage has the potential to function as an antivirulence agent, or a part of phage cocktails combined with phages targeting phage-resistant bacteria, against hvKP-relevant infections.
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Affiliation(s)
- Miran Tang
- Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University and Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Zeyu Huang
- Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University and Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xiaodong Zhang
- Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University and Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jingchun Kong
- Department of Medical Lab Science, School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Beibei Zhou
- Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University and Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Yijia Han
- Department of Medical Lab Science, School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Yi Zhang
- Department of Medical Lab Science, School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Lijiang Chen
- Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University and Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Tieli Zhou
- Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University and Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
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9
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Holmes CL, Wilcox AE, Forsyth V, Smith SN, Moricz BS, Unverdorben LV, Mason S, Wu W, Zhao L, Mobley HLT, Bachman MA. Klebsiella pneumoniae causes bacteremia using factors that mediate tissue-specific fitness and resistance to oxidative stress. PLoS Pathog 2023; 19:e1011233. [PMID: 37463183 PMCID: PMC10381055 DOI: 10.1371/journal.ppat.1011233] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 06/28/2023] [Indexed: 07/20/2023] Open
Abstract
Gram-negative bacteremia is a major cause of global morbidity involving three phases of pathogenesis: initial site infection, dissemination, and survival in the blood and filtering organs. Klebsiella pneumoniae is a leading cause of bacteremia and pneumonia is often the initial infection. In the lung, K. pneumoniae relies on many factors like capsular polysaccharide and branched chain amino acid biosynthesis for virulence and fitness. However, mechanisms directly enabling bloodstream fitness are unclear. Here, we performed transposon insertion sequencing (TnSeq) in a tail-vein injection model of bacteremia and identified 58 K. pneumoniae bloodstream fitness genes. These factors are diverse and represent a variety of cellular processes. In vivo validation revealed tissue-specific mechanisms by which distinct factors support bacteremia. ArnD, involved in Lipid A modification, was required across blood filtering organs and supported resistance to soluble splenic factors. The purine biosynthesis enzyme PurD supported liver fitness in vivo and was required for replication in serum. PdxA, a member of the endogenous vitamin B6 biosynthesis pathway, optimized replication in serum and lung fitness. The stringent response regulator SspA was required for splenic fitness yet was dispensable in the liver. In a bacteremic pneumonia model that incorporates initial site infection and dissemination, splenic fitness defects were enhanced. ArnD, PurD, DsbA, SspA, and PdxA increased fitness across bacteremia phases and each demonstrated unique fitness dynamics within compartments in this model. SspA and PdxA enhanced K. pnuemoniae resistance to oxidative stress. SspA, but not PdxA, specifically resists oxidative stress produced by NADPH oxidase Nox2 in the lung, spleen, and liver, as it was a fitness factor in wild-type but not Nox2-deficient (Cybb-/-) mice. These results identify site-specific fitness factors that act during the progression of Gram-negative bacteremia. Defining K. pneumoniae fitness strategies across bacteremia phases could illuminate therapeutic targets that prevent infection and sepsis.
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Affiliation(s)
- Caitlyn L Holmes
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Alexis E Wilcox
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Valerie Forsyth
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Sara N Smith
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Bridget S Moricz
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Lavinia V Unverdorben
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Sophia Mason
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Weisheng Wu
- Bioinformatics Core Facility, School of Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Lili Zhao
- Research Institute, Beaumont Hospital, Royal Oak, Michigan, United States of America
| | - Harry L T Mobley
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Michael A Bachman
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
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10
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Gautam I, Huss CW, Storad ZA, Krebs M, Bassiouni O, Ramesh R, Wuescher LM, Worth RG. Activated Platelets Mediate Monocyte Killing of Klebsiella pneumoniae. Infect Immun 2023; 91:e0055622. [PMID: 36853027 PMCID: PMC10016073 DOI: 10.1128/iai.00556-22] [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: 12/09/2022] [Accepted: 02/02/2023] [Indexed: 03/01/2023] Open
Abstract
Platelets are known for essential activities in hemostasis and for their important contribution to protection against infectious pathogens. Klebsiella pneumoniae is an opportunistic pathogen widely known to cause nosocomial infections. Recently, hypervirulent strains of K. pneumoniae have been emerging, which can cause severe infections in immunocompetent individuals. Combined with the increase in antibiotic resistance, it is important to understand how K. pneumoniae affects components of the immune system. We studied the interactions of human platelets with several K. pneumoniae strains (the wild type encapsulated strain, and a nonencapsulated mutant). Thrombin-stimulated whole human and mouse blood significantly inhibited bacterial growth compared to unstimulated whole blood. Furthermore, we investigated the effect of K. pneumoniae on platelet activation. Both strains induced significant increase in activation of both unstimulated and thrombin-stimulated human platelets. Additionally, only the nonencapsulated mutant increased aggregation of platelets in response to ADP. K. pneumoniae killing assays were then performed with washed platelets in the presence or absence of thrombin. Surprisingly, washed platelets failed to exhibit any effects on the growth of K. pneumoniae. We further explored the impact of platelets on monocyte-mediated killing of K. pneumoniae. Importantly, we found that activated platelets significantly enhanced monocyte-mediated killing of K. pneumoniae. This effect was likely due to the formation of platelet-monocyte aggregates in blood upon thrombin stimulation. Overall, this study highlights the role of platelets in mediating a protective response against K. pneumoniae and reinforces the importance of platelets in modulating leukocyte behavior.
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Affiliation(s)
- Iluja Gautam
- Department of Medical Microbiology and Immunology, University of Toledo, Toledo, Ohio, USA
| | - Chadwick W. Huss
- Department of Medical Microbiology and Immunology, University of Toledo, Toledo, Ohio, USA
| | - Zachary A. Storad
- Department of Medical Microbiology and Immunology, University of Toledo, Toledo, Ohio, USA
| | - Michelle Krebs
- Department of Medical Microbiology and Immunology, University of Toledo, Toledo, Ohio, USA
| | - Omar Bassiouni
- Department of Medical Microbiology and Immunology, University of Toledo, Toledo, Ohio, USA
| | - Rochan Ramesh
- Department of Medical Microbiology and Immunology, University of Toledo, Toledo, Ohio, USA
| | - Leah M. Wuescher
- Department of Medical Microbiology and Immunology, University of Toledo, Toledo, Ohio, USA
| | - Randall G. Worth
- Department of Medical Microbiology and Immunology, University of Toledo, Toledo, Ohio, USA
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11
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Genome-wide screen in human plasma identifies multifaceted complement evasion of Pseudomonas aeruginosa. PLoS Pathog 2023; 19:e1011023. [PMID: 36696456 PMCID: PMC9901815 DOI: 10.1371/journal.ppat.1011023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 02/06/2023] [Accepted: 11/23/2022] [Indexed: 01/26/2023] Open
Abstract
Pseudomonas aeruginosa, an opportunistic Gram-negative pathogen, is a leading cause of bacteremia with a high mortality rate. We recently reported that P. aeruginosa forms a persister-like sub-population of evaders in human plasma. Here, using a gain-of-function transposon sequencing (Tn-seq) screen in plasma, we identified and validated previously unknown factors affecting bacterial persistence in plasma. Among them, we identified a small periplasmic protein, named SrgA, whose expression leads to up to a 100-fold increase in resistance to killing. Additionally, mutants in pur and bio genes displayed higher tolerance and persistence, respectively. Analysis of several steps of the complement cascade and exposure to an outer-membrane-impermeable drug, nisin, suggested that the mutants impede membrane attack complex (MAC) activity per se. Electron microscopy combined with energy-dispersive X-ray spectroscopy (EDX) revealed the formation of polyphosphate (polyP) granules upon incubation in plasma of different size in purD and wild-type strains, implying the bacterial response to a stress signal. Indeed, inactivation of ppk genes encoding polyP-generating enzymes lead to significant elimination of persisting bacteria from plasma. Through this study, we shed light on a complex P. aeruginosa response to the plasma conditions and discovered the multifactorial origin of bacterial resilience to MAC-induced killing.
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12
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Nunez C, Kostoulias X, Peleg A, Short F, Qu Y. A comprehensive comparison of biofilm formation and capsule production for bacterial survival on hospital surfaces. Biofilm 2023; 5:100105. [PMID: 36711324 PMCID: PMC9880390 DOI: 10.1016/j.bioflm.2023.100105] [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: 12/03/2022] [Revised: 01/16/2023] [Accepted: 01/20/2023] [Indexed: 01/23/2023] Open
Abstract
Biofilm formation and capsule production are known microbial strategies used by bacterial pathogens to survive adverse conditions in the hospital environment. The relative importance of these strategies individually is unexplored. This project aims to compare the contributory roles of biofilm formation and capsule production in bacterial survival on hospital surfaces. Representative strains of bacterial species often causing hospital-acquired infections were selected, including Acinetobacter baumannii, Klebsiella pneumoniae, Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa. The importance of biofilm formation and capsule production on bacterial survival was evaluated by comparing capsule-positive wild-type and capsule-deficient mutant strains, and biofilm and planktonic growth modes respectively, against three adverse hospital conditions, including desiccation, benzalkonium chloride disinfection and ultraviolet (UV) radiation. Bacterial survival was quantitatively assessed using colony-forming unit (CFU) enumeration and the 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) assay and qualitatively by scanning electron microscopy (SEM). Correlations between capsule production and biofilm formation were further investigated. Biofilm formation contributed significantly to bacterial survival on hospital surface simulators, mediating high resistance to desiccation, benzalkonium chloride disinfection and UV radiation. The role of capsule production was minor and species-specific; encapsulated A. baumannii but not K. pneumoniae cells demonstrated slightly increased resistance to desiccation, and neither showed enhanced resistance to benzalkonium chloride. Interestingly, capsule production sensitized K. pneumoniae and A. baumannii to UV radiation. The loss of capsule in K. pneumoniae and A. baumannii enhanced biofilm formation, possibly by increasing cell surface hydrophobicity. In summary, this study confirms the crucial role of biofilm formation in bacterial survival on hospital surfaces. Conversely, encapsulation plays a relatively minor role and may even negatively impact bacterial biofilm formation and hospital survival.
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Affiliation(s)
- Charles Nunez
- Infection Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia
| | - Xenia Kostoulias
- Infection Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia,Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, Victoria, 3004, Australia
| | - Anton Peleg
- Infection Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia,Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, Victoria, 3004, Australia
| | - Francesca Short
- Infection Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia,Corresponding author.,
| | - Yue Qu
- Infection Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia,Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, Victoria, 3004, Australia,Corresponding author. Infection Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia.
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13
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Roney IJ, Rudner DZ. Two broadly conserved families of polyprenyl-phosphate transporters. Nature 2023; 613:729-734. [PMID: 36450357 PMCID: PMC10184681 DOI: 10.1038/s41586-022-05587-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 11/23/2022] [Indexed: 12/03/2022]
Abstract
Peptidoglycan and almost all surface glycopolymers in bacteria are built in the cytoplasm on the lipid carrier undecaprenyl phosphate (UndP)1-4. These UndP-linked precursors are transported across the membrane and polymerized or directly transferred to surface polymers, lipids or proteins. UndP is then flipped to regenerate the pool of cytoplasmic-facing UndP. The identity of the flippase that catalyses transport has remained unknown. Here, using the antibiotic amphomycin that targets UndP5-7, we identified two broadly conserved protein families that affect UndP recycling. One (UptA) is a member of the DedA superfamily8; the other (PopT) contains the domain DUF368. Genetic, cytological and syntenic analyses indicate that these proteins are UndP transporters. Notably, homologues from Gram-positive and Gram-negative bacteria promote UndP transport in Bacillus subtilis, indicating that recycling activity is broadly conserved among family members. Inhibitors of these flippases could potentiate the activity of antibiotics targeting the cell envelope.
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Affiliation(s)
- Ian J Roney
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
| | - David Z Rudner
- Department of Microbiology, Harvard Medical School, Boston, MA, USA.
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14
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Opoku-Temeng C, Freedman B, Porter AR, Kobayashi SD, Chen L, Kreiswirth BN, DeLeo FR. Subinhibitory Concentrations of Antibiotics Alter the Response of Klebsiella pneumoniae to Components of Innate Host Defense. Microbiol Spectr 2022; 10:e0151722. [PMID: 36264264 PMCID: PMC9769900 DOI: 10.1128/spectrum.01517-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 10/04/2022] [Indexed: 01/05/2023] Open
Abstract
Carbapenem-resistant Klebsiella pneumoniae isolates classified as multilocus sequence type 258 (ST258) are a problem in health care settings in many countries globally. ST258 isolates are resistant to multiple classes of antibiotics and can cause life-threatening infections, such as pneumonia and sepsis, in susceptible individuals. Treatment strategies for such infections are limited. Understanding the response of K. pneumoniae to host factors in the presence of antibiotics could reveal mechanisms employed by the pathogen to evade killing in the susceptible host, as well as inform treatment of infections. Here, we investigated the ability of antibiotics at subinhibitory concentrations to alter K. pneumoniae capsular polysaccharide (CPS) production and survival in normal human serum (NHS). Unexpectedly, pretreatment with some of the antibiotics tested enhanced ST258 survival in NHS. For example, a subinhibitory concentration of mupirocin increased survival for 7 of 10 clinical isolates evaluated and there was increased cell-associated CPS for 3 of these isolates compared with untreated controls. Additionally, mupirocin pretreatment caused concomitant reduction in the deposition of the serum complement protein C5b-9 on the surface of these three isolates. Transcriptome analyses with a selected ST258 isolate (34446) indicated that genes implicated in the stringent response and/or serum resistance were upregulated following mupirocin treatment and/or culture in NHS. In conclusion, mupirocin and/or human serum causes changes in the K. pneumoniae transcriptome that likely contribute to the observed decrease in serum susceptibility via a multifactorial process. Whether these responses can be extended more broadly and thus impact clinical outcome in the human host merits further investigation. IMPORTANCE The extent to which commensal bacteria are altered by exposure to subinhibitory concentrations of antibiotics (outside resistance) remains incompletely determined. To gain a better understanding of this phenomenon, we tested the ability of selected antibiotics (at subinhibitory concentrations) to alter survival of ST258 clinical isolates in normal human serum. We found that exposure of ST258 to antibiotics at low concentrations differentially altered gene expression, capsule production, serum complement deposition, and bacterial survival. The findings were isolate and antibiotic dependent but provide insight into a potential confounding issue associated with ST258 infections.
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Affiliation(s)
- Clement Opoku-Temeng
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Brett Freedman
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Adeline R. Porter
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Scott D. Kobayashi
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Liang Chen
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA
| | - Barry N. Kreiswirth
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA
| | - Frank R. DeLeo
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
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15
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Opstrup KV, Bennike TB, Christiansen G, Birkelund S. Complement killing of clinical Klebsiella pneumoniae isolates is serum concentration dependent. Microbes Infect 2022; 25:105074. [PMID: 36336240 DOI: 10.1016/j.micinf.2022.105074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 10/27/2022] [Accepted: 10/31/2022] [Indexed: 11/06/2022]
Abstract
Klebsiella pneumoniae is an opportunistic gram-negative pathogen causing serious infections, including sepsis. In plasma, activation of the complement cascades is important for killing bacteria. Thirty clinical Klebsiella spp. blood isolates were analyzed for serum susceptibility in 75% normal human serum (NHS). Twenty-two were serum resistant and eight were serum sensitive, and subsequently tested in 5-75% NHS. Two isolates were killed in 5% and the remaining six in 50%-75% NHS. The two 5% sensitive isolates showed binding of complement (C)4 and C3 in 5% NHS with formation of membrane attack complex (MAC). Inhibition of the classical/lectin mediated pathways (CP/LP) using a C4 specific nanobody, hC4Nb8, led to survival of both isolates in 5% NHS. Using nanobody hC3Nb1, inhibiting the alternative pathway (AP), the isolates were killed in 5% NHS, and amplification of the CP/LP by AP was not necessary for killing. Sole AP killing of these isolates when inhibiting CP/LP with hC4Nb8 was observed in 50% NHS, stressing the concentration dependent functionality of AP. For the less sensitive isolates, killing required activation of CP/LP and AP demonstrated by inhibition with nanobodies. AP inhibition resulted in no C3 deposition on the serum resistant isolate, supporting that AP was the sole activation pathway.
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Affiliation(s)
- Katharina V Opstrup
- Department of Health Science and Technology, Medical Microbiology and Immunology, Aalborg University, Fredrik Bajers Vej 5, 9220, Aalborg East, Denmark
| | - Tue B Bennike
- Department of Health Science and Technology, Medical Microbiology and Immunology, Aalborg University, Fredrik Bajers Vej 5, 9220, Aalborg East, Denmark
| | - Gunna Christiansen
- Department of Health Science and Technology, Medical Microbiology and Immunology, Aalborg University, Fredrik Bajers Vej 5, 9220, Aalborg East, Denmark
| | - Svend Birkelund
- Department of Health Science and Technology, Medical Microbiology and Immunology, Aalborg University, Fredrik Bajers Vej 5, 9220, Aalborg East, Denmark.
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16
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The Molecular Epidemiology of Prevalent Klebsiella pneumoniae Strains and Humoral Antibody Responses against Carbapenem-Resistant K. pneumoniae Infections among Pediatric Patients in Shanghai. mSphere 2022; 7:e0027122. [PMID: 36069436 PMCID: PMC9599505 DOI: 10.1128/msphere.00271-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Carbapenem-resistant Klebsiella pneumoniae (CRKP) has caused wide dissemination among pediatric patients globally and thus has aroused public concern. Here, we investigated the clinical epidemiological characteristics of 140 nonreplicate clinical K. pneumoniae strains isolated from pediatric patients between January and December 2021. Of all isolates, 16.43% (23 of 140) were CRKP strains, which predominantly contained KPC carbapenemase. wzi sequencing demonstrated that KL47 (65.22%, 15 of 23) was the most frequent capsular type, followed by KL64 (17.39%, 4 of 23). A total of 23 CRKP strains were classified into three different O-genotypes, including OL101 (65.22%, 15 of 23), O1 (26.09%, 6 of 23), and O3 (8.7%, 2 of 23). Interestingly, KL47 strains were strongly associated with OL101, while KL64 strains were all linked with O1. Some capsule-deficient strains were identified by serological typing, phage-typing, depolymerase-typing, and uronic acid assay. In this study, compared with healthy children, higher titers of anti-capsular polysaccharides (CPS) IgG were first detected in the sera of K47 and K64 K. pneumoniae-infected children, which had the effective bactericidal activity against corresponding serotype K. pneumoniae strains. These findings will facilitate the development of novel therapeutic and vaccine strategies against K. pneumoniae infection in children. IMPORTANCE The emergence of carbapenem-resistant Klebsiella pneumoniae (CRKP) strains resistant to numerous antibiotics and the limited therapeutic options available have become an urgent health threat to the immunocompromised pediatric population. Vaccines and antibodies, especially those targeting capsular polysaccharides, may be novel and effective prevention and treatment options. Thus, it is important to understand the spread of CRKP in pediatric populations. This research presents OL101:KL47 and O1:KL64 as the predominant combinations among CRKP strains in children in Shanghai, China. The primary carbapenemase gene is KPC in CRKP strains. Additionally, this study found elevated levels of anti-CPS IgG against K47 and K64 K. pneumoniae strains in pediatric patients for the first time. The significant bactericidal activity of these anti-CPS IgGs was confirmed.
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17
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Mackel JJ, Morffy Smith C, Wasbotten RK, Twentyman J, Rosen DA. Classical and γδ T cells are each independently sufficient to establish protection against a classical strain of Klebsiella pneumoniae. Front Cell Infect Microbiol 2022; 12:974175. [PMID: 36118033 PMCID: PMC9471189 DOI: 10.3389/fcimb.2022.974175] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 08/11/2022] [Indexed: 11/20/2022] Open
Abstract
Infections with classical strains of the Gram-negative bacterium Klebsiella pneumoniae pose a significant clinical challenge due to rising antibiotic resistance. We previously established a lung inoculation plus challenge model using live, classical K. pneumoniae in order to study host protection. Here, we employ this model to dissect adaptive immune responses to this critical pathogen. First, we performed convalescent serum transfers from inoculated mice to naïve recipients and found that classical K. pneumoniae infection outcomes, unlike hypervirulent K. pneumoniae infection outcomes, were not improved. This suggests that circulating antibody responses alone are not sufficient to mediate protection against this classical strain. Hence, we evaluated the role of T cells in protection against classical K. pneumoniae reinfection and demonstrated that mice lacking T cells are unable to establish a protective response. However, mice individually deficient in either of the major T cell subsets, γδ or αβ (classical T cells), effectively mount a protective response, indicating either subset alone is sufficient to mediate protection. Sequestration of T cells in secondary lymphoid organs during the challenge infection did not ablate protection, indicating the circulating T cell pool is not required for the protective phenotype. Finally, we demonstrate that depletion of T cells during initial infection eliminates protection against challenge. Collectively, these experiments demonstrate the imperative contribution of T cells to protective immunity against classical K. pneumoniae and will guide further inquiries into host effector responses required to control this infection.
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Affiliation(s)
- Joseph J. Mackel
- Department of Pediatrics, Division of Infectious Diseases, Washington University School of Medicine, Saint Louis, MO, United States
| | - Catherine Morffy Smith
- Department of Pediatrics, Division of Infectious Diseases, Washington University School of Medicine, Saint Louis, MO, United States
| | - Rachel K. Wasbotten
- Department of Pediatrics, Division of Infectious Diseases, Washington University School of Medicine, Saint Louis, MO, United States
| | - Joy Twentyman
- Department of Pediatrics, Division of Infectious Diseases, Washington University School of Medicine, Saint Louis, MO, United States
| | - David A. Rosen
- Department of Pediatrics, Division of Infectious Diseases, Washington University School of Medicine, Saint Louis, MO, United States
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO, United States
- *Correspondence: David A. Rosen,
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18
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Nucci A, Rocha EPC, Rendueles O. Adaptation to novel spatially-structured environments is driven by the capsule and alters virulence-associated traits. Nat Commun 2022; 13:4751. [PMID: 35963864 PMCID: PMC9376106 DOI: 10.1038/s41467-022-32504-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 08/02/2022] [Indexed: 12/14/2022] Open
Abstract
The extracellular capsule is a major virulence factor, but its ubiquity in free-living bacteria with large environmental breadths suggests that it shapes adaptation to novel niches. Yet, how it does so, remains unexplored. Here, we evolve three Klebsiella strains and their capsule mutants in parallel. Their comparison reveals different phenotypic and genotypic evolutionary changes that alter virulence-associated traits. Non-capsulated populations accumulate mutations that reduce exopolysaccharide production and increase biofilm formation and yield, whereas most capsulated populations become hypermucoviscous, a signature of hypervirulence. Hence, adaptation to novel environments primarily occurs by fine-tuning expression of the capsular locus. The same evolutionary conditions selecting for mutations in the capsular gene wzc leading to hypermucoviscosity also result in increased susceptibility to antibiotics by mutations in the ramA regulon. This implies that general adaptive processes outside the host can affect capsule evolution and its role in virulence and infection outcomes may be a by-product of such adaptation. Phenotypic and genotypic evolution in worrisome Klebsiella spp. is influenced by the capsule. Here the authors show that adaptation outside the host can impact virulence-associated traits, including de novo emergence of hypermucoviscosity.
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Affiliation(s)
- Amandine Nucci
- Institut Pasteur, Université de Paris, CNRS, UMR3525, Microbial Evolutionary Genomics, F-75015, Paris, France
| | - Eduardo P C Rocha
- Institut Pasteur, Université de Paris, CNRS, UMR3525, Microbial Evolutionary Genomics, F-75015, Paris, France
| | - Olaya Rendueles
- Institut Pasteur, Université de Paris, CNRS, UMR3525, Microbial Evolutionary Genomics, F-75015, Paris, France.
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19
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Holmes CL, Smith SN, Gurczynski SJ, Severin GB, Unverdorben LV, Vornhagen J, Mobley HLT, Bachman MA. The ADP-Heptose Biosynthesis Enzyme GmhB is a Conserved Gram-Negative Bacteremia Fitness Factor. Infect Immun 2022; 90:e0022422. [PMID: 35762751 PMCID: PMC9302095 DOI: 10.1128/iai.00224-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 06/12/2022] [Indexed: 11/29/2022] Open
Abstract
Klebsiella pneumoniae is a leading cause of Gram-negative bacteremia, which is a major source of morbidity and mortality worldwide. Gram-negative bacteremia requires three major steps: primary site infection, dissemination to the blood, and bloodstream survival. Because K. pneumoniae is a leading cause of health care-associated pneumonia, the lung is a common primary infection site leading to secondary bacteremia. K. pneumoniae factors essential for lung fitness have been characterized, but those required for subsequent bloodstream infection are unclear. To identify K. pneumoniae genes associated with dissemination and bloodstream survival, we combined previously and newly analyzed insertion site sequencing (InSeq) data from a murine model of bacteremic pneumonia. This analysis revealed the gene gmhB as important for either dissemination from the lung or bloodstream survival. In Escherichia coli, GmhB is a partially redundant enzyme in the synthesis of ADP-heptose for the lipopolysaccharide (LPS) core. To characterize its function in K. pneumoniae, an isogenic knockout strain (ΔgmhB) and complemented mutant were generated. During pneumonia, GmhB did not contribute to lung fitness and did not alter normal immune responses. However, GmhB enhanced bloodstream survival in a manner independent of serum susceptibility, specifically conveying resistance to spleen-mediated killing. In a tail-vein injection of murine bacteremia, GmhB was also required by K. pneumoniae, E. coli, and Citrobacter freundii for optimal fitness in the spleen and liver. Together, this study identifies GmhB as a conserved Gram-negative bacteremia fitness factor that acts through LPS-mediated mechanisms to enhance fitness in blood-filtering organs.
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Affiliation(s)
- Caitlyn L. Holmes
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan, USA
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Sara N. Smith
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Stephen J. Gurczynski
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Geoffrey B. Severin
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Lavinia V. Unverdorben
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan, USA
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Jay Vornhagen
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan, USA
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Harry L. T. Mobley
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Michael A. Bachman
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan, USA
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
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20
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Di Pilato V, Henrici De Angelis L, Aiezza N, Baccani I, Niccolai C, Parisio EM, Giordano C, Camarlinghi G, Barnini S, Forni S, Righi L, Mechi MT, Giani T, Antonelli A, Rossolini GM. Resistome and virulome accretion in an NDM-1-producing ST147 sublineage of Klebsiella pneumoniae associated with an outbreak in Tuscany, Italy: a genotypic and phenotypic characterisation. THE LANCET MICROBE 2022; 3:e224-e234. [DOI: 10.1016/s2666-5247(21)00268-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 08/26/2021] [Accepted: 09/23/2021] [Indexed: 10/24/2022] Open
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21
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Kamuyu G, Ercoli G, Ramos-Sevillano E, Willcocks S, Kewcharoenwong C, Kiratisin P, Taylor PW, Wren BW, Lertmemongkolchai G, Stabler RA, Brown JS. Strain Specific Variations in Acinetobacter baumannii Complement Sensitivity. Front Immunol 2022; 13:853690. [PMID: 35812377 PMCID: PMC9258041 DOI: 10.3389/fimmu.2022.853690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 05/27/2022] [Indexed: 12/02/2022] Open
Abstract
The complement system is required for innate immunity against Acinetobacter baumannii, an important cause of antibiotic resistant systemic infections. A. baumannii strains differ in their susceptibility to the membrane attack complex (MAC) formed from terminal complement pathway proteins, but the reasons for this variation remain poorly understood. We have characterized in detail the complement sensitivity phenotypes of nine A. baumannii clinical strains and some of the factors that might influence differences between strains. Using A. baumannii laboratory strains and flow cytometry assays, we first reconfirmed that both opsonization with the complement proteins C3b/iC3b and MAC formation were inhibited by the capsule. There were marked differences in C3b/iC3b and MAC binding between the nine clinical A. baumannii strains, but this variation was partially independent of capsule composition or size. Opsonization with C3b/iC3b improved neutrophil phagocytosis of most strains. Importantly, although C3b/iC3b binding and MAC formation on the bacterial surface correlated closely, MAC formation did not correlate with variations between A. baumannii strains in their levels of serum resistance. Genomic analysis identified only limited differences between strains in the distribution of genes required for serum resistance, but RNAseq data identified three complement-resistance genes that were differentially regulated between a MAC resistant and two MAC intermediate resistant strains when cultured in serum. These data demonstrate that clinical A. baumannii strains vary in their sensitivity to different aspects of the complement system, and that the serum resistance phenotype was influenced by factors in addition to the amount of MAC forming on the bacterial surface.
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Affiliation(s)
- Gathoni Kamuyu
- Centre for Inflammation and Tissue Repair, UCL Respiratory, University College London, London, United Kingdom
| | - Giuseppe Ercoli
- Centre for Inflammation and Tissue Repair, UCL Respiratory, University College London, London, United Kingdom
| | - Elisa Ramos-Sevillano
- Centre for Inflammation and Tissue Repair, UCL Respiratory, University College London, London, United Kingdom
| | - Sam Willcocks
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Chidchamai Kewcharoenwong
- Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
- Cellular and Molecular Immunology Unit, Centre for Research and Development of Medical Diagnostic Laboratories (CMDL), Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
| | - Pattarachai Kiratisin
- Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Peter W. Taylor
- School of Pharmacy, University College London, London, United Kingdom
| | - Brendan W. Wren
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Ganjana Lertmemongkolchai
- Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
- Cellular and Molecular Immunology Unit, Centre for Research and Development of Medical Diagnostic Laboratories (CMDL), Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
| | - Richard A. Stabler
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Jeremy S. Brown
- Centre for Inflammation and Tissue Repair, UCL Respiratory, University College London, London, United Kingdom
- *Correspondence: Jeremy S. Brown,
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22
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Molecular Mechanisms Involved in Pseudomonas aeruginosa Bacteremia. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1386:325-345. [DOI: 10.1007/978-3-031-08491-1_12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
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23
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Kaszowska M, Majkowska-Skrobek G, Markwitz P, Lood C, Jachymek W, Maciejewska A, Lukasiewicz J, Drulis-Kawa Z. The Mutation in wbaP cps Gene Cluster Selected by Phage-Borne Depolymerase Abolishes Capsule Production and Diminishes the Virulence of Klebsiella pneumoniae. Int J Mol Sci 2021; 22:11562. [PMID: 34768992 PMCID: PMC8583740 DOI: 10.3390/ijms222111562] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 10/21/2021] [Accepted: 10/21/2021] [Indexed: 12/20/2022] Open
Abstract
Klebsiella pneumoniae is considered one of the most critical multidrug-resistant pathogens and urgently requires new therapeutic strategies. Capsular polysaccharides (CPS), lipopolysaccharides (LPS), and exopolysaccharides (EPS) are the major virulence factors protecting K. pneumoniae against the immune response and thus may be targeted by phage-based therapeutics such as polysaccharides-degrading enzymes. Since the emergence of resistance to antibacterials is generally considered undesirable, in this study, the genetic and phenotypic characteristics of resistance to the phage-borne CPS-degrading depolymerase and its effect on K. pneumoniae virulence were investigated. The K63 serotype targeting depolymerase (KP36gp50) derived from Klebsiella siphovirus KP36 was used as the selective agent during the treatment of K. pneumoniae 486 biofilm. Genome-driven examination combined with the surface polysaccharide structural analysis of resistant mutant showed the point mutation and frameshift in the wbaP gene located within the cps gene cluster, resulting in the loss of the capsule. The sharp decline in the yield of CPS was accompanied by the production of a larger amount of smooth LPS. The modification of the surface polysaccharide layers did not affect bacterial fitness nor the insensitivity to serum complement; however, it made bacteria more prone to phagocytosis combined with the higher adherence and internalization to human lung epithelial cells. In that context, it was showed that the emerging resistance to the antivirulence agent (phage-borne capsule depolymerase) results in beneficial consequences, i.e., the sensitization to the innate immune response.
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Affiliation(s)
- Marta Kaszowska
- Laboratory of Microbial Immunochemistry and Vaccines, Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 53-114 Wroclaw, Poland; (M.K.); (W.J.); (A.M.)
| | - Grazyna Majkowska-Skrobek
- Department of Pathogen Biology and Immunology, University of Wroclaw, 51-148 Wroclaw, Poland; (G.M.-S.); (P.M.)
| | - Pawel Markwitz
- Department of Pathogen Biology and Immunology, University of Wroclaw, 51-148 Wroclaw, Poland; (G.M.-S.); (P.M.)
| | - Cédric Lood
- Department of Microbial and Molecular Systems, KU Leuven, 3001 Leuven, Belgium;
- Department of Biosystems, KU Leuven, 3001 Leuven, Belgium
| | - Wojciech Jachymek
- Laboratory of Microbial Immunochemistry and Vaccines, Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 53-114 Wroclaw, Poland; (M.K.); (W.J.); (A.M.)
| | - Anna Maciejewska
- Laboratory of Microbial Immunochemistry and Vaccines, Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 53-114 Wroclaw, Poland; (M.K.); (W.J.); (A.M.)
| | - Jolanta Lukasiewicz
- Laboratory of Microbial Immunochemistry and Vaccines, Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 53-114 Wroclaw, Poland; (M.K.); (W.J.); (A.M.)
| | - Zuzanna Drulis-Kawa
- Department of Pathogen Biology and Immunology, University of Wroclaw, 51-148 Wroclaw, Poland; (G.M.-S.); (P.M.)
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24
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Opoku-Temeng C, Malachowa N, Kobayashi SD, DeLeo FR. Innate Host Defense against Klebsiella pneumoniae and the Outlook for Development of Immunotherapies. J Innate Immun 2021; 14:167-181. [PMID: 34628410 DOI: 10.1159/000518679] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 07/14/2021] [Indexed: 11/19/2022] Open
Abstract
Klebsiella pneumoniae (K. pneumoniae) is a Gram-negative commensal bacterium and opportunistic pathogen. In healthy individuals, the innate immune system is adept at protecting against K. pneumoniae infection. Notably, the serum complement system and phagocytic leukocytes (e.g., neutrophils) are highly effective at eliminating K. pneumoniae and thereby preventing severe disease. On the other hand, the microbe is a major cause of healthcare-associated infections, especially in individuals with underlying susceptibility factors, such as pre-existing severe illness or immune suppression. The burden of K. pneumoniae infections in hospitals is compounded by antibiotic resistance. Treatment of these infections is often difficult largely because the microbes are usually resistant to multiple antibiotics (multidrug resistant [MDR]). There are a limited number of treatment options for these infections and new therapies, and preventative measures are needed. Here, we review host defense against K. pneumoniae and discuss recent therapeutic measures and vaccine approaches directed to treat and prevent severe disease caused by MDR K. pneumoniae.
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Affiliation(s)
- Clement Opoku-Temeng
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Natalia Malachowa
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Scott D Kobayashi
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Frank R DeLeo
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
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25
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Sahu SK, Kulkarni DH, Ozanturk AN, Ma L, Kulkarni HS. Emerging roles of the complement system in host-pathogen interactions. Trends Microbiol 2021; 30:390-402. [PMID: 34600784 DOI: 10.1016/j.tim.2021.09.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 09/01/2021] [Accepted: 09/06/2021] [Indexed: 12/12/2022]
Abstract
The complement system has historically been entertained as a fluid-phase, hepatically derived system which protects the intravascular space from encapsulated bacteria. However, there has been an increasing appreciation for its role in protection against non-encapsulated pathogens. Specifically, we have an improved understanding of how pathogens are recognized by specific complement proteins, as well as how they trigger and evade them. Additionally, we have an improved understanding of locally derived complement proteins, many of which promote host defense. Moreover, intracellular complement proteins have been identified that facilitate local protection and barrier function despite pathogen invasion. Our review aims to summarize these advances in the field as well as provide an insight into the pathophysiological changes occurring when the system is dysregulated in infection.
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Affiliation(s)
- Sanjaya K Sahu
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Devesha H Kulkarni
- Division of Gastroenterology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Ayse N Ozanturk
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Lina Ma
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Hrishikesh S Kulkarni
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA; Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA.
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26
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Dunstan RA, Bamert RS, Belousoff MJ, Short FL, Barlow CK, Pickard DJ, Wilksch JJ, Schittenhelm RB, Strugnell RA, Dougan G, Lithgow T. Mechanistic Insights into the Capsule-Targeting Depolymerase from a Klebsiella pneumoniae Bacteriophage. Microbiol Spectr 2021; 9:e0102321. [PMID: 34431721 PMCID: PMC8552709 DOI: 10.1128/spectrum.01023-21] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 08/02/2021] [Indexed: 02/07/2023] Open
Abstract
The production of capsular polysaccharides by Klebsiella pneumoniae protects the bacterial cell from harmful environmental factors such as antimicrobial compounds and infection by bacteriophages (phages). To bypass this protective barrier, some phages encode polysaccharide-degrading enzymes referred to as depolymerases to provide access to cell surface receptors. Here, we characterized the phage RAD2, which infects K. pneumoniae strains that produce the widespread, hypervirulence-associated K2-type capsular polysaccharide. Using transposon-directed insertion sequencing, we have shown that the production of capsule is an absolute requirement for efficient RAD2 infection by serving as a first-stage receptor. We have identified the depolymerase responsible for recognition and degradation of the capsule, determined that the depolymerase forms globular appendages on the phage virion tail tip, and present the cryo-electron microscopy structure of the RAD2 capsule depolymerase at 2.7-Å resolution. A putative active site for the enzyme was identified, comprising clustered negatively charged residues that could facilitate the hydrolysis of target polysaccharides. Enzymatic assays coupled with mass spectrometric analyses of digested oligosaccharide products provided further mechanistic insight into the hydrolase activity of the enzyme, which, when incubated with K. pneumoniae, removes the capsule and sensitizes the cells to serum-induced killing. Overall, these findings expand our understanding of how phages target the Klebsiella capsule for infection, providing a framework for the use of depolymerases as antivirulence agents against this medically important pathogen. IMPORTANCE Klebsiella pneumoniae is a medically important pathogen that produces a thick protective capsule that is essential for pathogenicity. Phages are natural predators of bacteria, and many encode diverse "capsule depolymerases" which specifically degrade the capsule of their hosts, an exploitable trait for potential therapies. We have determined the first structure of a depolymerase that targets the clinically relevant K2 capsule and have identified its putative active site, providing hints to its mechanism of action. We also show that Klebsiella cells treated with a recombinant form of the depolymerase are stripped of capsule, inhibiting their ability to grow in the presence of serum, demonstrating the anti-infective potential of these robust and readily producible enzymes against encapsulated bacterial pathogens such as K. pneumoniae.
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Affiliation(s)
- Rhys A. Dunstan
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Australia
- Centre to Impact AMR, Monash University, Clayton, Australia
| | - Rebecca S. Bamert
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Australia
- Centre to Impact AMR, Monash University, Clayton, Australia
| | - Matthew J. Belousoff
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Australia
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Francesca L. Short
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Australia
- Wellcome Sanger Institute, Hinxton, Cambridgeshire, United Kingdom
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Christopher K. Barlow
- Monash Proteomics & Metabolomics Facility, Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia
| | - Derek J. Pickard
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Jonathan J. Wilksch
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Australia
- Centre to Impact AMR, Monash University, Clayton, Australia
| | - Ralf B. Schittenhelm
- Monash Proteomics & Metabolomics Facility, Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia
| | - Richard A. Strugnell
- Department of Microbiology and Immunology, The Peter Doherty Institute, The University of Melbourne, Parkville, Australia
| | - Gordon Dougan
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Trevor Lithgow
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Australia
- Centre to Impact AMR, Monash University, Clayton, Australia
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27
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Xu Q, Yang X, Chan EWC, Chen S. The hypermucoviscosity of hypervirulent K. pneumoniae confers the ability to evade neutrophil-mediated phagocytosis. Virulence 2021; 12:2050-2059. [PMID: 34339346 PMCID: PMC8331041 DOI: 10.1080/21505594.2021.1960101] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Hypervirulent Klebsiella pneumoniae (HvKP), which causes highly fatal infections, is a new threat to human health. In an attempt to investigate the underlying mechanisms of resistance to neutrophil-mediated killing and hence expression of high-level virulence by HvKP, we tested the binding affinity of HvKP strains to various types of human cells. Our data showed that HvKP exhibited weaker binding to both lung epithelial cells, intestinal Caco-2 cells and macrophages when compared to the classic, non-hypervirulent strains (cKP). Consistently, transconjugants that have acquired a rmpA or rmpA2-bearing plasmid were found to exhibit decreased adhesion to various types of human cells, and hence higher survival rate upon exposure to neutrophil cells. We further found that over production of hypermucoviscosity (HMV), but not capsular polysaccharide (CPS), contributed to the reduced binding and phagocytosis. The effect of hypermucoviscosity on enhancing HvKP virulence was further shown in human serum survival assays and animal experiments. Findings in this study therefore confirmed that rmpA/A2-mediated hypermucoviscosity in HvKP plays a key role in the pathogenesis of this organism through conferring the ability to evade neutrophil binding and phagocytosis.
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Affiliation(s)
- Qi Xu
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong
| | - Xuemei Yang
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong
| | - Edward Wai Chi Chan
- State Key Lab of Chemical Biology and Drug Discovery, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Kowloon, Hong Kong
| | - Sheng Chen
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong
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28
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Blundell-Hunter G, Enright MC, Negus D, Dorman MJ, Beecham GE, Pickard DJ, Wintachai P, Voravuthikunchai SP, Thomson NR, Taylor PW. Characterisation of Bacteriophage-Encoded Depolymerases Selective for Key Klebsiella pneumoniae Capsular Exopolysaccharides. Front Cell Infect Microbiol 2021; 11:686090. [PMID: 34222050 PMCID: PMC8253255 DOI: 10.3389/fcimb.2021.686090] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 04/30/2021] [Indexed: 01/12/2023] Open
Abstract
Capsular polysaccharides enable clinically important clones of Klebsiella pneumoniae to cause severe systemic infections in susceptible hosts. Phage-encoded capsule depolymerases have the potential to provide an alternative treatment paradigm in patients when multiple drug resistance has eroded the efficacy of conventional antibiotic chemotherapy. An investigation of 164 K. pneumoniae from intensive care patients in Thailand revealed a large number of distinct K types in low abundance but four (K2, K51, K1, K10) with a frequency of at least 5%. To identify depolymerases with the capacity to degrade capsules associated with these common K-types, 62 lytic phage were isolated from Thai hospital sewage water using K1, K2 and K51 isolates as hosts; phage plaques, without exception, displayed halos indicative of the presence of capsule-degrading enzymes. Phage genomes ranged in size from 41-348 kb with between 50 and 535 predicted coding sequences (CDSs). Using a custom phage protein database we were successful in applying annotation to 30 - 70% (mean = 58%) of these CDSs. The largest genomes, of so-called jumbo phage, carried multiple tRNAs as well as CRISPR repeat and spacer sequences. One of the smaller phage genomes was found to contain a putative Cas type 1E gene, indicating a history of host DNA acquisition in these obligate lytic phage. Whole-genome sequencing (WGS) indicated that some phage displayed an extended host range due to the presence of multiple depolymerase genes; in total, 42 candidate depolymerase genes were identified with up to eight in a single genome. Seven distinct virions were selected for further investigation on the basis of host range, phage morphology and WGS. Candidate genes for K1, K2 and K51 depolymerases were expressed and purified as his6-tagged soluble protein and enzymatic activity demonstrated against K. pneumoniae capsular polysaccharides by gel electrophoresis and Anton-Paar rolling ball viscometry. Depolymerases completely removed the capsule in K-type-specific fashion from K. pneumoniae cells. We conclude that broad-host range phage carry multiple enzymes, each with the capacity to degrade a single K-type, and any future use of these enzymes as therapeutic agents will require enzyme cocktails for utility against a range of K. pneumoniae infections.
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Affiliation(s)
| | - Mark C. Enright
- Department of Life Sciences, Manchester Metropolitan University, Manchester, United Kingdom
| | - David Negus
- School of Science & Technology, Nottingham Trent University, Nottingham, United Kingdom
| | - Matthew J. Dorman
- Parasites and Microbes Programme, Wellcome Sanger Institute, Hinxton, United Kingdom
| | - Gemma E. Beecham
- School of Pharmacy, University College London, London, United Kingdom
| | - Derek J. Pickard
- Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, Cambridge, United Kingdom
| | | | | | - Nicholas R. Thomson
- Parasites and Microbes Programme, Wellcome Sanger Institute, Hinxton, United Kingdom
- Department of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Peter W. Taylor
- School of Pharmacy, University College London, London, United Kingdom
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29
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Abstract
Gram-negative bacteremia is a devastating public health threat, with high mortality in vulnerable populations and significant costs to the global economy. Concerningly, rates of both Gram-negative bacteremia and antimicrobial resistance in the causative species are increasing. Gram-negative bacteremia develops in three phases. First, bacteria invade or colonize initial sites of infection. Second, bacteria overcome host barriers, such as immune responses, and disseminate from initial body sites to the bloodstream. Third, bacteria adapt to survive in the blood and blood-filtering organs. To develop new therapies, it is critical to define species-specific and multispecies fitness factors required for bacteremia in model systems that are relevant to human infection. A small subset of species is responsible for the majority of Gram-negative bacteremia cases, including Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii The few bacteremia fitness factors identified in these prominent Gram-negative species demonstrate shared and unique pathogenic mechanisms at each phase of bacteremia progression. Capsule production, adhesins, and metabolic flexibility are common mediators, whereas only some species utilize toxins. This review provides an overview of Gram-negative bacteremia, compares animal models for bacteremia, and discusses prevalent Gram-negative bacteremia species.
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Affiliation(s)
- Caitlyn L Holmes
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan, USA
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Mark T Anderson
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Harry L T Mobley
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Michael A Bachman
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan, USA
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
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30
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Majkowska-Skrobek G, Markwitz P, Sosnowska E, Lood C, Lavigne R, Drulis-Kawa Z. The evolutionary trade-offs in phage-resistant Klebsiella pneumoniae entail cross-phage sensitization and loss of multidrug resistance. Environ Microbiol 2021; 23:7723-7740. [PMID: 33754440 DOI: 10.1111/1462-2920.15476] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 03/11/2021] [Accepted: 03/18/2021] [Indexed: 12/18/2022]
Abstract
Bacteriophage therapy is currently being evaluated as a critical complement to traditional antibiotic treatment. However, the emergence of phage resistance is perceived as a major hurdle to the sustainable implementation of this antimicrobial strategy. By combining comprehensive genomics and microbiological assessment, we show that the receptor-modification resistance to capsule-targeting phages involves either escape mutation(s) in the capsule biosynthesis cluster or qualitative changes in exopolysaccharides, converting clones to mucoid variants. These variants introduce cross-resistance to phages specific to the same receptor yet sensitize to phages utilizing alternative ones. The loss/modification of capsule, the main Klebsiella pneumoniae virulence factor, did not dramatically impact population fitness, nor the ability to protect bacteria against the innate immune response. Nevertheless, the introduction of phage drives bacteria to expel multidrug resistance clusters, as observed by the large deletion in K. pneumoniae 77 plasmid containing blaCTX-M , ant(3″), sul2, folA, mph(E)/mph(G) genes. The emerging bacterial resistance to viral infection steers evolution towards desired population attributes and highlights the synergistic potential for combined antibiotic-phage therapy against K. pneumoniae.
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Affiliation(s)
- Grazyna Majkowska-Skrobek
- Department of Pathogen Biology and Immunology, Institute of Genetics and Microbiology, University of Wroclaw, Wroclaw, Poland
| | - Pawel Markwitz
- Department of Pathogen Biology and Immunology, Institute of Genetics and Microbiology, University of Wroclaw, Wroclaw, Poland
| | - Ewelina Sosnowska
- Department of Pathogen Biology and Immunology, Institute of Genetics and Microbiology, University of Wroclaw, Wroclaw, Poland
| | - Cédric Lood
- Department of Biosystems, Laboratory of Gene Technology, KU Leuven, 3001 Heverlee, Belgium.,Department of Microbial and Molecular Systems, Centre of Microbial and Plant Genetics, Laboratory of Computational Systems Biology, KU Leuven, 3000 Leuven, Belgium
| | - Rob Lavigne
- Department of Biosystems, Laboratory of Gene Technology, KU Leuven, 3001 Heverlee, Belgium
| | - Zuzanna Drulis-Kawa
- Department of Pathogen Biology and Immunology, Institute of Genetics and Microbiology, University of Wroclaw, Wroclaw, Poland
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31
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Abstract
Klebsiella pneumoniae are Gram-negative facultative anaerobes that are found within host-associated commensal microbiomes, but they can also cause a wide range of infections that are often difficult to treat. These infections are caused by different pathotypes of K. pneumoniae, called either classical or hypervirulent strains. Klebsiella pneumoniae are Gram-negative facultative anaerobes that are found within host-associated commensal microbiomes, but they can also cause a wide range of infections that are often difficult to treat. These infections are caused by different pathotypes of K. pneumoniae, called either classical or hypervirulent strains. These two groups are genetically distinct, inhabit nonoverlapping geographies, and cause different types of harmful infections in humans. These distinct bacterial groups have also been found to interact differently with the host immune system. Initial innate immune defenses against K. pneumoniae infection include complement, macrophages, neutrophils, and monocytes; these defenses are primary strategies employed by the host to clear infections. K. pneumoniae pathogenesis depends upon the interactions between the microbe and each of these host defenses, and it is becoming increasingly apparent that bacterial genetic diversity impacts the outcomes of these interactions. Here, we highlight recent advances in our understanding of K. pneumoniae pathogenesis, with a focus on how bacterial evolution and diversity impact K. pneumoniae interactions with mammalian innate immune host defenses. We also discuss outstanding questions regarding how K. pneumoniae can frustrate normal immune responses, capitalize upon states of immunocompromise, and cause infections with high mortality.
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32
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Buffet A, Rocha EPC, Rendueles O. Nutrient conditions are primary drivers of bacterial capsule maintenance in Klebsiella. Proc Biol Sci 2021; 288:20202876. [PMID: 33653142 PMCID: PMC7935059 DOI: 10.1098/rspb.2020.2876] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2020] [Accepted: 02/05/2021] [Indexed: 02/06/2023] Open
Abstract
The fitness cost associated with the production of bacterial capsules is considered to be offset by the protection provided by these extracellular structures against biotic aggressions or abiotic stress. However, it is unknown if the capsule contributes to fitness in the absence of these. Here, we explored conditions favouring the maintenance of the capsule in Klebsiella pneumoniae, where the capsule is known to be a major virulence factor. Using short-term experimental evolution on different Klebsiella strains, we showed that small environmental variations have a strong impact on the maintenance of the capsule. Capsule inactivation is frequent in nutrient-rich, but scarce in nutrient-poor media. Competitions between wild-type and capsule mutants in nine different strains confirmed that the capsule is costly in nutrient-rich media. Surprisingly, these results also showed that the presence of a capsule provides a clear fitness advantage in nutrient-poor conditions by increasing both growth rates and population yields. The comparative analyses of the wild-type and capsule mutants reveal complex interactions between the environment, genetic background and serotype even in relation to traits known to be relevant during pathogenesis. In conclusion, our data suggest there are novel roles for bacterial capsules yet to be discovered and further supports the notion that the capsule's role in virulence may be a by-product of its contribution to bacterial adaptation outside the host.
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Affiliation(s)
- Amandine Buffet
- Microbial Evolutionary Genomics, Institut Pasteur, CNRS, UMR3525, Paris 75015, France
| | - Eduardo P. C. Rocha
- Microbial Evolutionary Genomics, Institut Pasteur, CNRS, UMR3525, Paris 75015, France
| | - Olaya Rendueles
- Microbial Evolutionary Genomics, Institut Pasteur, CNRS, UMR3525, Paris 75015, France
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33
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Mike LA, Stark AJ, Forsyth VS, Vornhagen J, Smith SN, Bachman MA, Mobley HLT. A systematic analysis of hypermucoviscosity and capsule reveals distinct and overlapping genes that impact Klebsiella pneumoniae fitness. PLoS Pathog 2021; 17:e1009376. [PMID: 33720976 PMCID: PMC7993769 DOI: 10.1371/journal.ppat.1009376] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 03/25/2021] [Accepted: 02/12/2021] [Indexed: 12/11/2022] Open
Abstract
Hypervirulent K. pneumoniae (hvKp) is a distinct pathotype that causes invasive community-acquired infections in healthy individuals. Hypermucoviscosity (hmv) is a major phenotype associated with hvKp characterized by copious capsule production and poor sedimentation. Dissecting the individual functions of CPS production and hmv in hvKp has been hindered by the conflation of these two properties. Although hmv requires capsular polysaccharide (CPS) biosynthesis, other cellular factors may also be required and some fitness phenotypes ascribed to CPS may be distinctly attributed to hmv. To address this challenge, we systematically identified genes that impact capsule and hmv. We generated a condensed, ordered transposon library in hypervirulent strain KPPR1, then evaluated the CPS production and hmv phenotypes of the 3,733 transposon mutants, representing 72% of all open reading frames in the genome. We employed forward and reverse genetic screens to evaluate effects of novel and known genes on CPS biosynthesis and hmv. These screens expand our understanding of core genes that coordinate CPS biosynthesis and hmv, as well as identify central metabolism genes that distinctly impact CPS biosynthesis or hmv, specifically those related to purine metabolism, pyruvate metabolism and the TCA cycle. Six representative mutants, with varying effect on CPS biosynthesis and hmv, were evaluated for their impact on CPS thickness, serum resistance, host cell association, and fitness in a murine model of disseminating pneumonia. Altogether, these data demonstrate that hmv requires both CPS biosynthesis and other cellular factors, and that hmv and CPS may serve distinct functions during pathogenesis. The integration of hmv and CPS to the metabolic status of the cell suggests that hvKp may require certain nutrients to specifically cause deep tissue infections.
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Affiliation(s)
- Laura A. Mike
- Department of Microbiology & Immunology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Andrew J. Stark
- Department of Microbiology & Immunology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Valerie S. Forsyth
- Department of Microbiology & Immunology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Jay Vornhagen
- Department of Pathology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Sara N. Smith
- Department of Microbiology & Immunology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Michael A. Bachman
- Department of Pathology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Harry L. T. Mobley
- Department of Microbiology & Immunology, University of Michigan, Ann Arbor, Michigan, United States of America
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34
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Bruchmann S, Feltwell T, Parkhill J, Short FL. Identifying virulence determinants of multidrug-resistant Klebsiella pneumoniae in Galleria mellonella. Pathog Dis 2021; 79:6123718. [PMID: 33512418 PMCID: PMC7981267 DOI: 10.1093/femspd/ftab009] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 01/26/2021] [Indexed: 12/30/2022] Open
Abstract
Infections caused by Klebsiella pneumoniae are a major public health threat. Extensively drug-resistant and even pan-resistant strains have been reported. Understanding K. pneumoniae pathogenesis is hampered by the fact that murine models of infection offer limited resolution for non-hypervirulent strains which cause the majority of infections. The insect Galleria mellonella larva is a widely used alternative model organism for bacterial pathogens. We have performed genome-scale fitness profiling of a multidrug-resistant K. pneumoniae ST258 strain during infection of G. mellonella, to determine if this model is suitable for large-scale virulence factor discovery in this pathogen. Our results demonstrated a dominant role for surface polysaccharides in infection, with contributions from siderophores, cell envelope proteins, purine biosynthesis genes and additional genes of unknown function. Comparison with a hypervirulent strain, ATCC 43816, revealed substantial overlap in important infection-related genes, as well as additional putative virulence factors specific to ST258, reflecting strain-dependent fitness effects. Our analysis also identified a role for the metalloregulatory protein NfeR (YqjI) in virulence. Overall, this study offers new insight into the infection fitness landscape of K. pneumoniae, and provides a framework for using the highly flexible and easily scalable G. mellonella infection model to dissect molecular virulence mechanisms of bacterial pathogens.
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Affiliation(s)
- Sebastian Bruchmann
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, CB3 0ES, UK.,Pathogen Genomics, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, CB10 1SA, UK
| | - Theresa Feltwell
- Pathogen Genomics, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, CB10 1SA, UK.,Department of Medicine, University of Cambridge, The Old Schools, Cambridge, CB2 3PU, UK
| | - Julian Parkhill
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, CB3 0ES, UK
| | - Francesca L Short
- Pathogen Genomics, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, CB10 1SA, UK.,Department of Medicine, University of Cambridge, The Old Schools, Cambridge, CB2 3PU, UK.,Department of Molecular Sciences, Macquarie University, North Ryde, NSW 2113, Australia
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35
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Javed M, Jentzsch B, Heinrich M, Ueltzhoeffer V, Peter S, Schoppmeier U, Angelov A, Schwarz S, Willmann M. Transcriptomic Basis of Serum Resistance and Virulence Related Traits in XDR P. aeruginosa Evolved Under Antibiotic Pressure in a Morbidostat Device. Front Microbiol 2021; 11:619542. [PMID: 33569046 PMCID: PMC7868568 DOI: 10.3389/fmicb.2020.619542] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 12/30/2020] [Indexed: 01/11/2023] Open
Abstract
Colistin is a last resort antibiotic against the critical status pathogen Pseudomonas aeruginosa. Virulence and related traits such as biofilm formation and serum resistance after exposure to sub-inhibitory levels of colistin have been underexplored. We cultivated P. aeruginosa in a semi-automated morbidostat device with colistin, metronidazole and a combination of the two antibiotics for 21 days, and completed RNA-Seq to uncover the transcriptional changes over time. Strains became resistant to colistin within this time period. Colistin-resistant strains show significantly increased biofilm formation: the cell density in biofilm increases under exposure to colistin, while the addition of metronidazole can remove this effect. After 7 days of colistin exposure, strains develop an ability to grow in serum, suggesting that colistin drives bacterial modifications conferring a protective effect from serum complement factors. Of note, strains exposed to colistin showed a decrease in virulence, when measured using the Galleria mellonella infection model. These phenotypic changes were characterized by a series of differential gene expression changes, particularly those related to LPS modifications, spermidine synthesis (via speH and speE) and the major stress response regulator rpoS. Our results suggest a clinically important bacterial evolution under sub-lethal antibiotic concentration leading to potential for significant changes in the clinical course of infection.
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Affiliation(s)
- Mumina Javed
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Institute of Medical Microbiology and Hygiene, Tübingen, Germany.,German Center for Infection Research (DZIF), Partner Site Tübingen, Tübingen, Germany
| | - Benedikt Jentzsch
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Institute of Medical Microbiology and Hygiene, Tübingen, Germany.,German Center for Infection Research (DZIF), Partner Site Tübingen, Tübingen, Germany
| | - Maximilian Heinrich
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Institute of Medical Microbiology and Hygiene, Tübingen, Germany.,German Center for Infection Research (DZIF), Partner Site Tübingen, Tübingen, Germany
| | - Viola Ueltzhoeffer
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Institute of Medical Microbiology and Hygiene, Tübingen, Germany
| | - Silke Peter
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Institute of Medical Microbiology and Hygiene, Tübingen, Germany.,German Center for Infection Research (DZIF), Partner Site Tübingen, Tübingen, Germany
| | - Ulrich Schoppmeier
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Institute of Medical Microbiology and Hygiene, Tübingen, Germany
| | - Angel Angelov
- NGS Competence Center Tübingen (NCCT), Tübingen, Germany
| | - Sandra Schwarz
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Institute of Medical Microbiology and Hygiene, Tübingen, Germany
| | - Matthias Willmann
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Institute of Medical Microbiology and Hygiene, Tübingen, Germany.,German Center for Infection Research (DZIF), Partner Site Tübingen, Tübingen, Germany.,Eurofins MVZ Medizinisches Labor Gelsenkirchen, Gelsenkirchen, Germany
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36
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Wang B, Artsimovitch I. NusG, an Ancient Yet Rapidly Evolving Transcription Factor. Front Microbiol 2021; 11:619618. [PMID: 33488562 PMCID: PMC7819879 DOI: 10.3389/fmicb.2020.619618] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 12/07/2020] [Indexed: 12/19/2022] Open
Abstract
Timely and accurate RNA synthesis depends on accessory proteins that instruct RNA polymerase (RNAP) where and when to start and stop transcription. Among thousands of transcription factors, NusG/Spt5 stand out as the only universally conserved family of regulators. These proteins interact with RNAP to promote uninterrupted RNA synthesis and with diverse cellular partners to couple transcription to RNA processing, modification or translation, or to trigger premature termination of aberrant transcription. NusG homologs are present in all cells that utilize bacterial-type RNAP, from endosymbionts to plants, underscoring their ancient and essential function. Yet, in stark contrast to other core RNAP components, NusG family is actively evolving: horizontal gene transfer and sub-functionalization drive emergence of NusG paralogs, such as bacterial LoaP, RfaH, and UpxY. These specialized regulators activate a few (or just one) operons required for expression of antibiotics, capsules, secretion systems, toxins, and other niche-specific macromolecules. Despite their common origin and binding site on the RNAP, NusG homologs differ in their target selection, interacting partners and effects on RNA synthesis. Even among housekeeping NusGs from diverse bacteria, some factors promote pause-free transcription while others slow the RNAP down. Here, we discuss structure, function, and evolution of NusG proteins, focusing on unique mechanisms that determine their effects on gene expression and enable bacterial adaptation to diverse ecological niches.
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Affiliation(s)
- Bing Wang
- Department of Microbiology and the Center for RNA Biology, The Ohio State University, Columbus, OH, United States
| | - Irina Artsimovitch
- Department of Microbiology and the Center for RNA Biology, The Ohio State University, Columbus, OH, United States
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37
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Pont S, Fraikin N, Caspar Y, Van Melderen L, Attrée I, Cretin F. Bacterial behavior in human blood reveals complement evaders with some persister-like features. PLoS Pathog 2020; 16:e1008893. [PMID: 33326490 PMCID: PMC7773416 DOI: 10.1371/journal.ppat.1008893] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 12/30/2020] [Accepted: 11/03/2020] [Indexed: 12/17/2022] Open
Abstract
Bacterial bloodstream infections (BSI) are a major health concern and can cause up to 40% mortality. Pseudomonas aeruginosa BSI is often of nosocomial origin and is associated with a particularly poor prognosis. The mechanism of bacterial persistence in blood is still largely unknown. Here, we analyzed the behavior of a cohort of clinical and laboratory Pseudomonas aeruginosa strains in human blood. In this specific environment, complement was the main defensive mechanism, acting either by direct bacterial lysis or by opsonophagocytosis, which required recognition by immune cells. We found highly variable survival rates for different strains in blood, whatever their origin, serotype, or the nature of their secreted toxins (ExoS, ExoU or ExlA) and despite their detection by immune cells. We identified and characterized a complement-tolerant subpopulation of bacterial cells that we named “evaders”. Evaders shared some features with bacterial persisters, which tolerate antibiotic treatment. Notably, in bi-phasic killing curves, the evaders represented 0.1–0.001% of the initial bacterial load and displayed transient tolerance. However, the evaders are not dormant and require active metabolism to persist in blood. We detected the evaders for five other major human pathogens: Acinetobacter baumannii, Burkholderia multivorans, enteroaggregative Escherichia coli, Klebsiella pneumoniae, and Yersinia enterocolitica. Thus, the evaders could allow the pathogen to persist within the bloodstream, and may be the cause of fatal bacteremia or dissemination, in particular in the absence of effective antibiotic treatments. Blood infections by antibiotic resistant bacteria, notably Pseudomonas aeruginosa, are major concerns in hospital settings. The complex interplay between P. aeruginosa and the innate immune system in the context of human blood is still poorly understood. By studying the behavior of various P. aeruginosa strains in human whole blood and plasma, we showed that bacterial strains display different rate of tolerance to the complement system. Despite the complement microbicide activity, most bacteria withstand elimination through phenotypic heterogeneity creating a tiny (<0.1%) subpopulation of transiently tolerant evaders able to persist in plasma. This phenotypic heterogeneity thus prevents total elimination of the pathogen from the circulation, and represents a new strategy to disseminate within the organism.
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Affiliation(s)
- Stéphane Pont
- Université Grenoble Alpes, Bacterial Pathogenesis and Cellular Responses team, CNRS ERL5261, CEA IRIG-BCI, INSERM UMR1036, Grenoble, France
| | - Nathan Fraikin
- Université Libre de Bruxelles, Department of Molecular Biology, Cellular & Molecular Microbiology, Gosselies, Belgium
| | - Yvan Caspar
- Centre Hospitalier Universitaire Grenoble Alpes, Laboratoire de bactériologie-hygiène hospitalière, Grenoble, France
- Université Grenoble Alpes, CNRS, Grenoble INP, TIMC-IMAG, Grenoble, France
| | - Laurence Van Melderen
- Université Libre de Bruxelles, Department of Molecular Biology, Cellular & Molecular Microbiology, Gosselies, Belgium
| | - Ina Attrée
- Université Grenoble Alpes, Bacterial Pathogenesis and Cellular Responses team, CNRS ERL5261, CEA IRIG-BCI, INSERM UMR1036, Grenoble, France
- * E-mail: (FC); (IA)
| | - François Cretin
- Université Grenoble Alpes, Bacterial Pathogenesis and Cellular Responses team, CNRS ERL5261, CEA IRIG-BCI, INSERM UMR1036, Grenoble, France
- * E-mail: (FC); (IA)
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