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Abán CL, Orosco S, Argañaraz Aybar JN, Albarracín L, Venecia A, Perret L, Ortiz Mayor S, Nishiyama K, Valdéz JC, Kitazawa H, Villena J, Gobbato N. Effect of Lactiplantibacillus plantarum cell-free culture on bacterial pathogens isolated from cystic fibrosis patients: in vitro and in vivo studies. Front Microbiol 2024; 15:1440090. [PMID: 39351305 PMCID: PMC11439784 DOI: 10.3389/fmicb.2024.1440090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Accepted: 08/06/2024] [Indexed: 10/04/2024] Open
Abstract
This study aimed to investigate the effects of the cell-free supernatant of Lactiplantibacillus plantarum ATCC® 10241TM on the biofilm-forming capacity of Pseudomonas aeruginosa strains isolated from cystic fibrosis (CF) patients. In addition, the study evaluated the in vivo potential of the cell-free supernatant to modulate inflammation and reduce lung damage in mice infected with P. aeruginosa strains or co-challenged with P. aeruginosa and the Streptococcus milleri group (SMG). The results showed that CF-derived P. aeruginosa strains can infect the respiratory tract of adult mice, inducing local inflammation and lung damage. The severity of these infections was exacerbated when P. aeruginosa was co-administered with SMG. Notably, nebulization with the cell-free supernatant of L. plantarum produced beneficial effects, reducing respiratory infection severity and inflammatory responses induced by P. aeruginosa, both alone or in combination with SMG. Reduced bacterial loads and lung damage were observed in supernatant-treated mice compared to controls. Although further mechanistic studies are necessary, the results show that the cell-free supernatant of L. plantarum ATCC® 10241TM is an interesting adjuvant alternative to treat P. aeruginosa respiratory infections and superinfections in CF patients.
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Affiliation(s)
- Carla Luciana Abán
- National Council of Scientific and Technological Research (CONICET)–CCT (Salta-Jujuy), Salta, Argentina
| | - Silvia Orosco
- Pneumonology Department, Niño Jesus Children Hospital, SIPROSA, Tucuman, Argentina
| | - Julio Nicolás Argañaraz Aybar
- Laboratory of Immunology, Faculty of Biochemistry, Chemistry and Pharmacy, National University of Tucuman, Tucuman, Argentina
| | - Leonardo Albarracín
- Laboratory of Immunobiotechnology, Reference Centre for Lactobacilli (CERELA-CONICET), Tucuman, Argentina
| | - Analía Venecia
- Institute of Maternity and Gynecology “Nuestra Señora de las Mercedes”, SIPROSA, Tucuman, Argentina
| | - Liliana Perret
- Rehabilitation Department of the Integrated Health Program of the Ministry of Health of the Tucuman Province, Tucuman, Argentina
| | - Sonia Ortiz Mayor
- Hospital Centro de Salud “Zenon Santillan”, SIPROSA, Tucuman, Argentina
| | - Keita Nishiyama
- Food and Feed Immunology Group, Laboratory of Animal Food Function, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
- Livestock Immunology Unit, International Education and Research Center for Food and Agricultural Immunology (CFAI), Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Juan Carlos Valdéz
- Laboratory of Immunology, Faculty of Biochemistry, Chemistry and Pharmacy, National University of Tucuman, Tucuman, Argentina
| | - Haruki Kitazawa
- Food and Feed Immunology Group, Laboratory of Animal Food Function, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
- Livestock Immunology Unit, International Education and Research Center for Food and Agricultural Immunology (CFAI), Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Julio Villena
- Laboratory of Immunology, Faculty of Biochemistry, Chemistry and Pharmacy, National University of Tucuman, Tucuman, Argentina
- Food and Feed Immunology Group, Laboratory of Animal Food Function, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Nadia Gobbato
- Laboratory of Immunology, Faculty of Biochemistry, Chemistry and Pharmacy, National University of Tucuman, Tucuman, Argentina
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Sendra E, Fernández-Muñoz A, Zamorano L, Oliver A, Horcajada JP, Juan C, Gómez-Zorrilla S. Impact of multidrug resistance on the virulence and fitness of Pseudomonas aeruginosa: a microbiological and clinical perspective. Infection 2024; 52:1235-1268. [PMID: 38954392 PMCID: PMC11289218 DOI: 10.1007/s15010-024-02313-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Accepted: 05/30/2024] [Indexed: 07/04/2024]
Abstract
Pseudomonas aeruginosa is one of the most common nosocomial pathogens and part of the top emergent species associated with antimicrobial resistance that has become one of the greatest threat to public health in the twenty-first century. This bacterium is provided with a wide set of virulence factors that contribute to pathogenesis in acute and chronic infections. This review aims to summarize the impact of multidrug resistance on the virulence and fitness of P. aeruginosa. Although it is generally assumed that acquisition of resistant determinants is associated with a fitness cost, several studies support that resistance mutations may not be associated with a decrease in virulence and/or that certain compensatory mutations may allow multidrug resistance strains to recover their initial fitness. We discuss the interplay between resistance profiles and virulence from a microbiological perspective but also the clinical consequences in outcomes and the economic impact.
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Affiliation(s)
- Elena Sendra
- Infectious Diseases Service, Hospital del Mar, Infectious Pathology and Antimicrobials Research Group (IPAR), Hospital del Mar Research Institute, Universitat Autònoma de Barcelona (UAB), CEXS-Universitat Pompeu Fabra, Passeig Marítim 25-27, 08003, Barcelona, Spain
| | - Almudena Fernández-Muñoz
- Research Unit, University Hospital Son Espases-Health Research Institute of the Balearic Islands (IdISBa), Microbiology Department, University Hospital Son Espases, Crtra. Valldemossa 79, 07010, Palma, Spain
| | - Laura Zamorano
- Research Unit, University Hospital Son Espases-Health Research Institute of the Balearic Islands (IdISBa), Microbiology Department, University Hospital Son Espases, Crtra. Valldemossa 79, 07010, Palma, Spain
| | - Antonio Oliver
- Research Unit, University Hospital Son Espases-Health Research Institute of the Balearic Islands (IdISBa), Microbiology Department, University Hospital Son Espases, Crtra. Valldemossa 79, 07010, Palma, Spain
- Center for Biomedical Research in Infectious Diseases Network (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
| | - Juan Pablo Horcajada
- Infectious Diseases Service, Hospital del Mar, Infectious Pathology and Antimicrobials Research Group (IPAR), Hospital del Mar Research Institute, Universitat Autònoma de Barcelona (UAB), CEXS-Universitat Pompeu Fabra, Passeig Marítim 25-27, 08003, Barcelona, Spain
- Center for Biomedical Research in Infectious Diseases Network (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
| | - Carlos Juan
- Research Unit, University Hospital Son Espases-Health Research Institute of the Balearic Islands (IdISBa), Microbiology Department, University Hospital Son Espases, Crtra. Valldemossa 79, 07010, Palma, Spain.
- Center for Biomedical Research in Infectious Diseases Network (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain.
| | - Silvia Gómez-Zorrilla
- Infectious Diseases Service, Hospital del Mar, Infectious Pathology and Antimicrobials Research Group (IPAR), Hospital del Mar Research Institute, Universitat Autònoma de Barcelona (UAB), CEXS-Universitat Pompeu Fabra, Passeig Marítim 25-27, 08003, Barcelona, Spain.
- Center for Biomedical Research in Infectious Diseases Network (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain.
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3
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Gholami A, Minai-Tehrani D, Farewell A, Eriksson LA. Discovery of novel inhibitors for Pseudomonas aeruginosa lipase enzyme from in silico and in vitro studies. J Biomol Struct Dyn 2024; 42:2197-2210. [PMID: 37098781 DOI: 10.1080/07391102.2023.2203258] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 04/10/2023] [Indexed: 04/27/2023]
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen prone to developing drug-resistance and is a major cause of infection for burn patients and patients suffering from cystic fibrosis or are hospitalized in intensive care units. One of the virulence factors of this bacterium is the lipase enzyme that degrades the extracellular matrix of the host tissue and promotes invasion. Bromhexine is a mucolytic drug and has recently been reported to function as a competitive inhibitor of lipase with an IC50 value of 49 µM. In the present study, an attempt was made to identify stronger inhibitors from the ChEMBL database of bioactive compounds, as compared to the reference compound Bromhexine. Following docking and MD simulations, four hit compounds (N1-N4) were selected that showed promising binding modes and low RMSD values indicative of stable protein-ligand complexes. From subsequent binding pose metadynamics (BPMD) simulations, two of these (N2 and N4) stood out as more potent than Bromhexine, displaying stable interactions with residues in the catalytic site of the enzyme. Biological investigations were performed for all four compounds. Among them, the same two hit compounds were found to be the most effective binders with IC50 values of 22.1 and 27.5 µM, respectively; i.e. roughly twice as efficient as the reference Bromhexine. Taken together, our results show that these hits can be promising new candidates to use as leads for the development of drugs targeting the P. aeruginosa lipase enzyme.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Asma Gholami
- Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran
- Department of Chemistry and Molecular Biology, University of Gothenburg, Göteborg, Sweden
| | - Dariush Minai-Tehrani
- Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran
| | - Anne Farewell
- Department of Chemistry and Molecular Biology, University of Gothenburg, Göteborg, Sweden
- Centre for Antibiotic Resistance Research, University of Gothenburg, Göteborg, Sweden
| | - Leif A Eriksson
- Department of Chemistry and Molecular Biology, University of Gothenburg, Göteborg, Sweden
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Duan X, Boo ZZ, Chua SL, Chong KHC, Long Z, Yang R, Zhou Y, Janela B, Chotirmall SH, Ginhoux F, Hu Q, Wu B, Yang L. A Bacterial Quorum Sensing Regulated Protease Inhibits Host Immune Responses by Cleaving Death Domains of Innate Immune Adaptors. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2304891. [PMID: 37870218 PMCID: PMC10700182 DOI: 10.1002/advs.202304891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 09/28/2023] [Indexed: 10/24/2023]
Abstract
Innate immune adaptor proteins are critical components of the innate immune system that propagate pro-inflammatory responses from their upstream receptors, and lead to pathogen clearance from the host. Bacterial pathogens have developed strategies to survive inside host cells without triggering the innate immune surveillance in ways that are still not fully understood. Here, it is reported that Pseudomonas aeruginosa induces its quorum sensing mechanism after macrophage engulfment. Further investigation of its secretome identified a quorum sensing regulated product, LasB, is responsible for innate immune suppression depending on the MyD88-mediated signaling. Moreover, it is showed that this specific type of pathogen-mediated innate immune suppression is due to the enzymatic digestion of the death domains of the innate immune adaptors, mainly MyD88, and attributed to LasB's large substrate binding groove. Lastly, it is demonstrated that the secretion of LasB from P. aeruginosa directly contributed to MyD88 degradation within macrophages. Hence, it is discovered an example of bacterial quorum sensing-regulated cellular innate immune suppression by direct cleavage of immune adaptors.
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Affiliation(s)
- Xiangke Duan
- Shenzhen Third People's HospitalThe Second Affiliated Hospital of Southern University of Science and TechnologyNational Clinical Research Center for Infectious DiseaseShenzhen518112P. R. China
- School of MedicineSouthern University of Science and TechnologyShenzhenGuangdong518055P. R. China
- Shenzhen Center for Disease, Control and PreventionShenzhen518055P.R. China
| | - Zhao Zhi Boo
- School of Biological SciencesNanyang Technological UniversitySingapore637551Singapore
- NTU Institute of Structural BiologyNanyang Technological UniversitySingapore636921Singapore
| | - Song Lin Chua
- Department of Applied Biology and Chemical TechnologyThe Hong Kong Polytechnic UniversityHong Kong SAR999077P. R. China
| | - Kelvin Han Chung Chong
- School of Biological SciencesNanyang Technological UniversitySingapore637551Singapore
- NTU Institute of Structural BiologyNanyang Technological UniversitySingapore636921Singapore
| | - Ziqi Long
- School of Biological SciencesNanyang Technological UniversitySingapore637551Singapore
- NTU Institute of Structural BiologyNanyang Technological UniversitySingapore636921Singapore
| | - Renliang Yang
- School of Biological SciencesNanyang Technological UniversitySingapore637551Singapore
- NTU Institute of Structural BiologyNanyang Technological UniversitySingapore636921Singapore
| | - Yachun Zhou
- Shenzhen Third People's HospitalThe Second Affiliated Hospital of Southern University of Science and TechnologyNational Clinical Research Center for Infectious DiseaseShenzhen518112P. R. China
- School of MedicineSouthern University of Science and TechnologyShenzhenGuangdong518055P. R. China
| | - Baptiste Janela
- Skin Research Institute of SingaporeSingapore308232Singapore
- Lee Kong Chian School of MedicineNanyang Technological UniversitySingapore639798Singapore
| | | | - Florent Ginhoux
- Singapore Immunology NetworkAgency for Science, Technology and Research (A*STAR)8A Biomedical Grove, ImmunosSingapore138648Singapore
| | - Qinghua Hu
- Shenzhen Center for Disease, Control and PreventionShenzhen518055P.R. China
| | - Bin Wu
- School of Biological SciencesNanyang Technological UniversitySingapore637551Singapore
- NTU Institute of Structural BiologyNanyang Technological UniversitySingapore636921Singapore
| | - Liang Yang
- Shenzhen Third People's HospitalThe Second Affiliated Hospital of Southern University of Science and TechnologyNational Clinical Research Center for Infectious DiseaseShenzhen518112P. R. China
- School of MedicineSouthern University of Science and TechnologyShenzhenGuangdong518055P. R. China
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5
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Zhao Y, Chen D, Chen K, Xie M, Guo J, Chan EWC, Xie L, Wang J, Chen E, Chen S, Chen W, Jelsbak L. Epidemiological and Genetic Characteristics of Clinical Carbapenem-Resistant Pseudomonas aeruginosa Strains in Guangdong Province, China. Microbiol Spectr 2023; 11:e0426122. [PMID: 37078855 PMCID: PMC10269565 DOI: 10.1128/spectrum.04261-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 03/27/2023] [Indexed: 04/21/2023] Open
Abstract
Carbapenem-resistant Pseudomonas aeruginosa (CRPA) is a bacterial pathogen that may cause serious drug-resistant infections that are potentially fatal. To investigate the genetic characteristics of these organisms, we tested 416 P. aeruginosa strains recovered from 12 types of clinical samples collected in 29 different hospital wards in 10 hospitals in Guangdong Province, China, from 2017 to 2020. These strains were found to belong to 149 known sequence types (STs) and 72 novel STs, indicating that transmission of these strains involved multiple routes. A high rate of resistance to imipenem (89.4%) and meropenem (79.4%) and a high prevalence of pathogenic serotypes (76.4%) were observed among these strains. Six STs of global high-risk clones (HiRiCs) and a novel HiRiC strains, ST1971, which exhibited extensive drug resistance, were identified. Importantly, ST1971 HiRiC, which was unique in China, also exhibited high virulence, which alarmed the further surveillance on this highly virulent and highly resistant clone. Inactivation of the oprD gene and overexpression of efflux systems were found to be mainly responsible for carbapenem resistance in these strains; carriage of metallo-β-lactamase (MBL)-encoding genes was less common. Interestingly, frameshift mutations (49.0%) and introduction of a stop codon (22.4%) into the oprD genes were the major mechanisms of imipenem resistance. On the other hand, expression of the MexAB-OprM efflux pump and MBL-encoding genes were mechanisms of resistance in >70% of meropenem-resistant strains. The findings presented here provide insights into the development of effective strategies for control of worldwide dissemination of CRPA. IMPORTANCE Carbapenem-resistant Pseudomonas aeruginosa (CRPA) is a major concern in clinical settings worldwide, yet few genetic and epidemiological studies on CRPA strains have been performed in China. Here, we sequence and analyze the genomes of 416 P. aeruginosa strains from hospitals in China to elucidate the genetic, phenotypic, and transmission characteristics of CRPA strains and to identify the molecular signatures responsible for the observed increase in the prevalence of CRPA infections in China. These findings may provide new insight into the development of effective strategies for worldwide control of CRPA and minimize the occurrence of untreatable infections in clinical settings.
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Affiliation(s)
- Yonggang Zhao
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark
| | - Dingqiang Chen
- Microbiome Medicine Center, Department of Laboratory Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, People’s Republic of China
| | - Kaichao Chen
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, People’s Republic of China
| | - Miaomiao Xie
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, People’s Republic of China
| | - Jiubiao Guo
- College of Pharmacy-Shenzhen Technology University, Shenzhen, People’s Republic of China
| | - Edward Wai Chi Chan
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, People’s Republic of China
| | - Lu Xie
- Research Center for Micro-Ecological Agent Engineering and Technology of Guangdong Province, Guangzhou, People’s Republic of China
| | - Jingbo Wang
- College of Pharmacy-Shenzhen Technology University, Shenzhen, People’s Republic of China
| | - Enqi Chen
- College of Pharmacy-Shenzhen Technology University, Shenzhen, People’s Republic of China
| | - Sheng Chen
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, People’s Republic of China
| | - Weijun Chen
- BGI-Shenzhen, Shenzhen, People’s Republic of China
| | - Lars Jelsbak
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark
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Mansor MR, AL-Khalidi ZS, Almuhanna EH, Hussein HR, Almulla AF, Alnaji HA. Detection and Study nan1 and tox A genes of Pseudomonas aeruginosa in Isolates from Otitis Media Patients Considered as Virulence Factors. IRANIAN JOURNAL OF MEDICAL MICROBIOLOGY 2023. [DOI: 10.30699/ijmm.17.1.81] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/14/2023]
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7
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Wang C, Ye Q, Ding Y, Zhang J, Gu Q, Pang R, Zhao H, Wang J, Wu Q. Detection of Pseudomonas aeruginosa Serogroup G Using Real-Time PCR for Novel Target Genes Identified Through Comparative Genomics. Front Microbiol 2022; 13:928154. [PMID: 35814691 PMCID: PMC9263582 DOI: 10.3389/fmicb.2022.928154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 06/07/2022] [Indexed: 11/20/2022] Open
Abstract
Accurate serotyping is essential for effective infection control. Pseudomonas aeruginosa serogroup G is one of the most common serogroups found in water. Conventional serotyping methods are not standardized and have several shortcomings. Therefore, a robust method for rapidly identifying P. aeruginosa serotypes is required. This study established a real-time PCR method for identifying P. aeruginosa serogroup G strains using novel target gene primers based on comparative genomic analysis. A total of 343 genome sequences, including 16 P. aeruginosa serogroups and 67 other species, were analyzed. Target genes identified were amplified using real-time PCR for detecting P. aeruginosa serogroup G strains. Eight serogroup G genes, PA59_01276, PA59_01887, PA59_01888, PA59_01891, PA59_01894, PA59_04268, PA59_01892, and PA59_01896, were analyzed to determine specific targets. A real-time fluorescence quantitative PCR method, based on the novel target PA59_01276, was established to detect and identify serogroup G strains. The specificity of this method was confirmed using P. aeruginosa serogroups and non-P. aeruginosa species. The sensitivity of this real-time PCR method was 4 × 102 CFU/mL, and it could differentiate and detect P. aeruginosa serogroup G in the range of 4.0 × 103–4.0 × 108 CFU/mL in artificially contaminated drinking water samples without enrichment. The sensitivity of these detection limits was higher by 1–3 folds compared to that of the previously reported PCR methods. In addition, the G serum group was accurately detected using this real-time PCR method without interference by high concentrations of artificially contaminated serum groups F and D. These results indicate that this method has high sensitivity and accuracy and is promising for identifying and rapidly detecting P. aeruginosa serogroup G in water samples. Moreover, this research will contribute to the development of effective vaccines and therapies for infections caused by multidrug-resistant P. aeruginosa.
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Affiliation(s)
- Chufang Wang
- College of Food Science, South China Agricultural University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
- Key Laboratory of Agricultural Microbiomics and Precision Application, Ministry of Agriculture and Rural Affairs, Guangdong Academy of Sciences, Guangzhou, China
| | - Qinghua Ye
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
- Key Laboratory of Agricultural Microbiomics and Precision Application, Ministry of Agriculture and Rural Affairs, Guangdong Academy of Sciences, Guangzhou, China
| | - Yu Ding
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
- Key Laboratory of Agricultural Microbiomics and Precision Application, Ministry of Agriculture and Rural Affairs, Guangdong Academy of Sciences, Guangzhou, China
| | - Jumei Zhang
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
- Key Laboratory of Agricultural Microbiomics and Precision Application, Ministry of Agriculture and Rural Affairs, Guangdong Academy of Sciences, Guangzhou, China
| | - Qihui Gu
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
- Key Laboratory of Agricultural Microbiomics and Precision Application, Ministry of Agriculture and Rural Affairs, Guangdong Academy of Sciences, Guangzhou, China
| | - Rui Pang
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
- Key Laboratory of Agricultural Microbiomics and Precision Application, Ministry of Agriculture and Rural Affairs, Guangdong Academy of Sciences, Guangzhou, China
| | - Hui Zhao
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
- Key Laboratory of Agricultural Microbiomics and Precision Application, Ministry of Agriculture and Rural Affairs, Guangdong Academy of Sciences, Guangzhou, China
| | - Juan Wang
- College of Food Science, South China Agricultural University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
- Key Laboratory of Agricultural Microbiomics and Precision Application, Ministry of Agriculture and Rural Affairs, Guangdong Academy of Sciences, Guangzhou, China
- *Correspondence: Juan Wang,
| | - Qingping Wu
- College of Food Science, South China Agricultural University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
- Key Laboratory of Agricultural Microbiomics and Precision Application, Ministry of Agriculture and Rural Affairs, Guangdong Academy of Sciences, Guangzhou, China
- Qingping Wu,
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8
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Huber P. ExlA: A New Contributor to Pseudomonas aeruginosa Virulence. Front Cell Infect Microbiol 2022; 12:929150. [PMID: 35811671 PMCID: PMC9260685 DOI: 10.3389/fcimb.2022.929150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 05/19/2022] [Indexed: 11/17/2022] Open
Abstract
ExlA (also called exolysin) is a recently discovered virulence factor secreted by a subset of Pseudomonas aeruginosa strains in which a type 3 secretion system is lacking. exlA-positive strains were identified worldwide in the clinic, causing several types of infectious diseases, and were detected in various locations in the environment. ExlA possesses pore-forming activity and is cytolytic for most human cell types. It belongs to a class of poorly characterized bacterial toxins, sharing a similar protein domain organization and a common secretion pathway. This review summarizes the recent findings regarding ExlA synthesis, its secretion pathway, and its toxic behavior for host cells.
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Wolfmeier H, Wardell SJT, Liu LT, Falsafi R, Draeger A, Babiychuk EB, Pletzer D, Hancock REW. Targeting the Pseudomonas aeruginosa Virulence Factor Phospholipase C With Engineered Liposomes. Front Microbiol 2022; 13:867449. [PMID: 35369481 PMCID: PMC8971843 DOI: 10.3389/fmicb.2022.867449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 02/28/2022] [Indexed: 11/13/2022] Open
Abstract
Engineered liposomes composed of the naturally occurring lipids sphingomyelin (Sm) and cholesterol (Ch) have been demonstrated to efficiently neutralize toxins secreted by Gram-positive bacteria such as Streptococcus pneumoniae and Staphylococcus aureus. Here, we hypothesized that liposomes are capable of neutralizing cytolytic virulence factors secreted by the Gram-negative pathogen Pseudomonas aeruginosa. We used the highly virulent cystic fibrosis P. aeruginosa Liverpool Epidemic Strain LESB58 and showed that sphingomyelin (Sm) and a combination of sphingomyelin with cholesterol (Ch:Sm; 66 mol/% Ch and 34 mol/% Sm) liposomes reduced lysis of human bronchial and red blood cells upon challenge with the Pseudomonas secretome. Mass spectrometry of liposome-sequestered Pseudomonas proteins identified the virulence-promoting hemolytic phospholipase C (PlcH) as having been neutralized. Pseudomonas aeruginosa supernatants incubated with liposomes demonstrated reduced PlcH activity as assessed by the p-nitrophenylphosphorylcholine (NPPC) assay. Testing the in vivo efficacy of the liposomes in a murine cutaneous abscess model revealed that Sm and Ch:Sm, as single dose treatments, attenuated abscesses by >30%, demonstrating a similar effect to that of a mutant lacking plcH in this infection model. Thus, sphingomyelin-containing liposome therapy offers an interesting approach to treat and reduce virulence of complex infections caused by P. aeruginosa and potentially other Gram-negative pathogens expressing PlcH.
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Affiliation(s)
- Heidi Wolfmeier
- Department of Microbiology and Immunology, Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
- Institute of Anatomy and Cell Biology, Paracelsus Medical University, Salzburg, Austria
| | - Samuel J. T. Wardell
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Leo T. Liu
- Department of Microbiology and Immunology, Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
| | - Reza Falsafi
- Department of Microbiology and Immunology, Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
| | | | | | - Daniel Pletzer
- Department of Microbiology and Immunology, Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
- *Correspondence: Daniel Pletzer,
| | - Robert E. W. Hancock
- Department of Microbiology and Immunology, Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
- Robert E. W. Hancock,
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10
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Nasrin S, Hegerle N, Sen S, Nkeze J, Sen S, Permala-Booth J, Choi M, Sinclair J, Tapia MD, Johnson JK, Sow SO, Thaden JT, Fowler VG, Krogfelt KA, Brauner A, Protonotariou E, Christaki E, Shindo Y, Kwa AL, Shakoor S, Singh-Moodley A, Perovic O, Jacobs J, Lunguya O, Simon R, Cross AS, Tennant SM. Distribution of serotypes and antibiotic resistance of invasive Pseudomonas aeruginosa in a multi-country collection. BMC Microbiol 2022; 22:13. [PMID: 34991476 PMCID: PMC8732956 DOI: 10.1186/s12866-021-02427-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 12/06/2021] [Indexed: 12/22/2022] Open
Abstract
Background Pseudomonas aeruginosa is an opportunistic pathogen that causes a wide range of acute and chronic infections and is frequently associated with healthcare-associated infections. Because of its ability to rapidly acquire resistance to antibiotics, P. aeruginosa infections are difficult to treat. Alternative strategies, such as a vaccine, are needed to prevent infections. We collected a total of 413 P. aeruginosa isolates from the blood and cerebrospinal fluid of patients from 10 countries located on 4 continents during 2005–2017 and characterized these isolates to inform vaccine development efforts. We determined the diversity and distribution of O antigen and flagellin types and antibiotic susceptibility of the invasive P. aeruginosa. We used an antibody-based agglutination assay and PCR for O antigen typing and PCR for flagellin typing. We determined antibiotic susceptibility using the Kirby-Bauer disk diffusion method. Results Of the 413 isolates, 314 (95%) were typed by an antibody-based agglutination assay or PCR (n = 99). Among the 20 serotypes of P. aeruginosa, the most common serotypes were O1, O2, O3, O4, O5, O6, O8, O9, O10 and O11; a vaccine that targets these 10 serotypes would confer protection against more than 80% of invasive P. aeruginosa infections. The most common flagellin type among 386 isolates was FlaB (41%). Resistance to aztreonam (56%) was most common, followed by levofloxacin (42%). We also found that 22% of strains were non-susceptible to meropenem and piperacillin-tazobactam. Ninety-nine (27%) of our collected isolates were resistant to multiple antibiotics. Isolates with FlaA2 flagellin were more commonly multidrug resistant (p = 0.04). Conclusions Vaccines targeting common O antigens and two flagellin antigens, FlaB and FlaA2, would offer an excellent strategy to prevent P. aeruginosa invasive infections. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-021-02427-4.
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Affiliation(s)
- Shamima Nasrin
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, 685 W. Baltimore St. - HSF1 Room 480, Baltimore, MD, 21201, USA.,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Nicolas Hegerle
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, 685 W. Baltimore St. - HSF1 Room 480, Baltimore, MD, 21201, USA.,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Shaichi Sen
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, 685 W. Baltimore St. - HSF1 Room 480, Baltimore, MD, 21201, USA.,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Joseph Nkeze
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, 685 W. Baltimore St. - HSF1 Room 480, Baltimore, MD, 21201, USA.,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Sunil Sen
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, 685 W. Baltimore St. - HSF1 Room 480, Baltimore, MD, 21201, USA.,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Jasnehta Permala-Booth
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, 685 W. Baltimore St. - HSF1 Room 480, Baltimore, MD, 21201, USA.,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Myeongjin Choi
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, 685 W. Baltimore St. - HSF1 Room 480, Baltimore, MD, 21201, USA.,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - James Sinclair
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, 685 W. Baltimore St. - HSF1 Room 480, Baltimore, MD, 21201, USA.,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Milagritos D Tapia
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, 685 W. Baltimore St. - HSF1 Room 480, Baltimore, MD, 21201, USA.,Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD, USA
| | - J Kristie Johnson
- Department of Pathology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Samba O Sow
- Centre pour le Développement des Vaccins, Mali, Bamako, Mali
| | - Joshua T Thaden
- Division of Infectious Diseases, Duke University Medical Center, Durham, NC, USA
| | - Vance G Fowler
- Division of Infectious Diseases and International Health, Department of Medicine, Duke University School of Medicine, Durham, NC, USA.,Duke Clinical Research Institute, Durham, NC, USA
| | - Karen A Krogfelt
- Statens Serum Institut, Copenhagen, Denmark.,Department of Natural Sciences and Environment, Roskilde University, Roskilde, Denmark
| | - Annelie Brauner
- Department of Microbiology, Tumor and Cell Biology, Division of Clinical Microbiology, Karolinska Institutet and Karolinska University Hospital, 17176, Stockholm, Sweden
| | | | - Eirini Christaki
- Department of Medicine, AHEPA University Hospital, Thessaloniki, Greece.,University of Cyprus Medical School, Nicosia, Cyprus
| | - Yuichiro Shindo
- Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Andrea L Kwa
- Department of Pharmacy, Singapore General Hospital, Singapore, Singapore.,Emerging Infectious Diseases, Duke-National University of Singapore Medical School, Singapore, Singapore.,Department of Pharmacy, Faculty of Science, National University of Singapore, Singapore, Singapore
| | - Sadia Shakoor
- Departments of Pathology and Pediatrics, Aga Khan University, Karachi, Pakistan
| | - Ashika Singh-Moodley
- National Institute for Communicable Diseases a Division of the National Health Laboratory Service, and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Olga Perovic
- National Institute for Communicable Diseases a Division of the National Health Laboratory Service, and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Jan Jacobs
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium.,Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium
| | - Octavie Lunguya
- Department of Clinical Microbiology, National Institute for Biomedical Research, Kinshasa, Democratic Republic of the Congo.,Department of Microbiology, University Hospital of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Raphael Simon
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, 685 W. Baltimore St. - HSF1 Room 480, Baltimore, MD, 21201, USA.,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Alan S Cross
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, 685 W. Baltimore St. - HSF1 Room 480, Baltimore, MD, 21201, USA.,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Sharon M Tennant
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, 685 W. Baltimore St. - HSF1 Room 480, Baltimore, MD, 21201, USA. .,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.
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11
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Zupetic J, Peñaloza HF, Bain W, Hulver M, Mettus R, Jorth P, Doi Y, Bomberger J, Pilewski J, Nouraie M, Lee JS. Elastase Activity From Pseudomonas aeruginosa Respiratory Isolates and ICU Mortality. Chest 2021; 160:1624-1633. [PMID: 33878342 PMCID: PMC8628173 DOI: 10.1016/j.chest.2021.04.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 04/07/2021] [Accepted: 04/10/2021] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Pseudomonas aeruginosa (PA) is a common cause of respiratory infection and morbidity. Pseudomonas elastase is an important virulence factor regulated by the lasR gene. Whether PA elastase activity is associated with worse clinical outcomes in ICU patients is unknown. RESEARCH QUESTION Is there an association between PA elastase activity and worse host outcomes in a cohort of ICU patients? METHODS PA respiratory isolates from 238 unique ICU patients from two tertiary-care centers within the University of Pittsburgh Medical Center health system were prospectively collected and screened for total protease and elastase activity, biofilm production, antimicrobial resistance, and polymicrobial status. The association between pathogen characteristics and 30-day and 90-day mortality was calculated using logistic regression. For subgroup analysis, two patterns of early (≤72 h) and late sample (>72 h) collection from the index ICU admission were distinguished using a finite mixture model. Lung inflammation and injury was evaluated in a mouse model using a PA high elastase vs low elastase producer. RESULTS PA elastase activity was common in ICU respiratory isolates representing 75% of samples and was associated with increased 30-day mortality (adjusted OR [95% CI]: 1.39 [1.05-1.83]). Subgroup analysis demonstrated that elastase activity was a risk factor for 30- and 90-day mortality in the early sample group, whereas antimicrobial resistance was a risk factor for 90-day mortality in the late sample group. Whole genome sequencing of high and low elastase producers showed that predicted loss-of-function lasR genotypes were less common among high elastase producers. Mice infected with a high elastase producer showed increased lung bacterial burden and inflammatory profile compared with mice infected with a low elastase producer. INTERPRETATION Elastase activity is associated with 30-day ICU mortality. A high elastase producing clinical isolate confers increased lung tissue inflammation compared with a low elastase producer in vivo.
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Affiliation(s)
- Jill Zupetic
- Acute Lung Injury Center of Excellence, Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA
| | - Hernán F Peñaloza
- Acute Lung Injury Center of Excellence, Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA
| | - William Bain
- Acute Lung Injury Center of Excellence, Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA
| | - Mei Hulver
- Acute Lung Injury Center of Excellence, Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA
| | - Roberta Mettus
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh, Pittsburgh, PA
| | - Peter Jorth
- Department of Pathology and Laboratory Medicine, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Yohei Doi
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh, Pittsburgh, PA
| | - Jennifer Bomberger
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh, Pittsburgh, PA
| | - Joseph Pilewski
- Acute Lung Injury Center of Excellence, Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA
| | - Mehdi Nouraie
- Acute Lung Injury Center of Excellence, Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA; Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA
| | - Janet S Lee
- Acute Lung Injury Center of Excellence, Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA; Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA.
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12
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Recio R, Viedma E, González-Bodí S, Villa J, Orellana MÁ, Mancheño-Losa M, Lora-Tamayo J, Chaves F. Clinical and bacterial characteristics of Pseudomonas aeruginosa affecting the outcome of patients with bacteraemic pneumonia. Int J Antimicrob Agents 2021; 58:106450. [PMID: 34644604 DOI: 10.1016/j.ijantimicag.2021.106450] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 09/22/2021] [Accepted: 10/02/2021] [Indexed: 12/29/2022]
Abstract
Few studies have assessed the clinical and bacterial characteristics of Pseudomonas aeruginosa (PA) bacteraemic pneumonia (BP) episodes. This study analysed all non-duplicate PA-BP episodes from a tertiary hospital in 2013-2017. Epidemiology, clinical data, antimicrobial therapy and outcomes were recorded. Whole-genome sequencing was performed on PA blood isolates. The impact on early and late overall mortality of host, antimicrobial treatment and pathogen factors was assessed by multivariate logistic regression analysis. Of 55 PA-BP episodes, 32 (58.2%) were caused by extensively drug-resistant (XDR) PA. ST175 (32.7%) and ST235 (25.5%) were the most frequent high-risk clones. β-Lactamases/carbapenemases were detected in 29 isolates, including blaVIM-2 (27.2%) and blaGES type (25.5%) [blaGES-5 (20.0%), blaGES-1 (3.6%) and blaGES-20 (1.8%)]. The most prevalent O-antigen serotypes were O4 (34.5%) and O11 (30.9%). Overall, an extensive virulome was identified in all isolates. Early mortality (56.4%) was independently associated with severe neutropenia (aOR = 4.64, 95% CI 1.11-19.33; P = 0.035) and inappropriate empirical antimicrobial therapy (aOR = 5.71, 95% CI 1.41-22.98; P = 0.014). Additionally, late mortality (67.3%) was influenced by septic shock (aOR = 8.85, 95% CI 2.00-39.16; P = 0.004) and XDR phenotype (aOR = 5.46, 95% CI 1.25-23.85; P = 0.024). Moreover, specific genetic backgrounds [ST235, blaGES, gyrA (T83I), parC (S87L), exoU and O11 serotype] showed significant differences in patient outcomes. Our results confirm the high mortality associated with PA-BP. Besides relevant clinical characteristics and inappropriate empirical therapy, bacteria-specific genetics factors, such as XDR phenotype, adversely affect the outcome of PA-BP.
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Affiliation(s)
- Raúl Recio
- Department of Clinical Microbiology, Instituto de Investigación Hospital 12 de Octubre (imas12), Hospital Universitario 12 de Octubre, Madrid, Spain.
| | - Esther Viedma
- Department of Clinical Microbiology, Instituto de Investigación Hospital 12 de Octubre (imas12), Hospital Universitario 12 de Octubre, Madrid, Spain
| | - Sara González-Bodí
- Department of Clinical Microbiology, Instituto de Investigación Hospital 12 de Octubre (imas12), Hospital Universitario 12 de Octubre, Madrid, Spain
| | - Jennifer Villa
- Department of Clinical Microbiology, Instituto de Investigación Hospital 12 de Octubre (imas12), Hospital Universitario 12 de Octubre, Madrid, Spain
| | - María Ángeles Orellana
- Department of Clinical Microbiology, Instituto de Investigación Hospital 12 de Octubre (imas12), Hospital Universitario 12 de Octubre, Madrid, Spain
| | - Mikel Mancheño-Losa
- Department of Internal Medicine, Instituto de Investigación Hospital 12 de Octubre (imas12), Hospital Universitario 12 de Octubre, Madrid, Spain
| | - Jaime Lora-Tamayo
- Department of Internal Medicine, Instituto de Investigación Hospital 12 de Octubre (imas12), Hospital Universitario 12 de Octubre, Madrid, Spain
| | - Fernando Chaves
- Department of Clinical Microbiology, Instituto de Investigación Hospital 12 de Octubre (imas12), Hospital Universitario 12 de Octubre, Madrid, Spain
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13
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A Primed Subpopulation of Bacteria Enables Rapid Expression of the Type 3 Secretion System in Pseudomonas aeruginosa. mBio 2021; 12:e0083121. [PMID: 34154400 PMCID: PMC8262847 DOI: 10.1128/mbio.00831-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Type 3 secretion systems (T3SS) are complex nanomachines that span the cell envelope and play a central role in the biology of Gram-negative pathogens and symbionts. In Pseudomonas aeruginosa, T3SS expression is strongly associated with human disease severity and with mortality in murine acute pneumonia models. Uniform exposure of isogenic cells to T3SS-activating signal results in heterogeneous expression of this critical virulence trait. To understand the function of such diversity, we measured the production of the T3SS master regulator ExsA and the expression of T3SS genes using fluorescent reporters. We found that heterogeneous expression of ExsA in the absence of activating signal generates a "primed" subpopulation of cells that can rapidly induce T3SS gene expression in response to signal. T3SS expression is accompanied by a reproductive trade-off as measured by increased division time of T3SS-expressing cells. Although T3SS-primed cells are a minority of the population, they compose the majority of T3SS-expressing cells for several hours following activation. The primed state therefore allows P. aeruginosa to maximize reproductive fitness while maintaining the capacity to quickly express the T3SS. As T3SS effectors can serve as shared public goods for nonproducing cells, this division of labor benefits the population as a whole. IMPORTANCE The expression of specific virulence traits is strongly associated with Pseudomonas aeruginosa's success in establishing acute infections but is thought to carry a cost for bacteria. Producing multiprotein secretion systems or motility organelles is metabolically expensive and can target a cell for recognition by innate immune system receptors that recognize structural components of the type 3 secretion system (T3SS) or flagellum. These acute virulence factors are also negatively selected when P. aeruginosa establishes chronic infections in the lung. We demonstrate a regulatory mechanism by which only a minority subpopulation of genetically identical P. aeruginosa cells is "primed" to respond to signals that turn on T3SS expression. This phenotypic heterogeneity allows the population to maximize the benefit of rapid T3SS effector production while maintaining a rapidly growing and nonexpressing reservoir of cells that perpetuates this genotype within the population.
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14
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Fangous MS, Gosset P, Galakhoff N, Gouriou S, Guilloux CA, Payan C, Vallet S, Héry-Arnaud G, Le Berre R. Priming with intranasal lactobacilli prevents Pseudomonas aeruginosa acute pneumonia in mice. BMC Microbiol 2021; 21:195. [PMID: 34182930 PMCID: PMC8237558 DOI: 10.1186/s12866-021-02254-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 06/09/2021] [Indexed: 11/10/2022] Open
Abstract
Background Increasing resistance to antibiotics of Pseudomonas aeruginosa leads to therapeutic deadlock and alternative therapies are needed. We aimed to evaluate the effects of Lactobacillus clinical isolates in vivo, through intranasal administration on a murine model of Pseudomonas aeruginosa pneumonia. Results We screened in vitro 50 pulmonary clinical isolates of Lactobacillus for their ability to decrease the synthesis of two QS dependent-virulence factors (elastase and pyocyanin) produced by Pseudomonas aeruginosa strain PAO1. Two blends of three Lactobacillus isolates were then tested in vivo: one with highly effective anti-PAO1 virulence factors properties (blend named L.rff for L. rhamnosus, two L. fermentum strains), and the second with no properties (blend named L.psb, for L. paracasei, L. salivarius and L. brevis). Each blend was administered intranasally to mice 18 h prior to PAO1 pulmonary infection. Animal survival, bacterial loads, cytological analysis, and cytokines secretion in the lungs were evaluated at 6 or 24 h post infection with PAO1. Intranasal priming with both lactobacilli blends significantly improved 7-day mice survival from 12% for the control PAO1 group to 71 and 100% for the two groups receiving L.rff and L.psb respectively. No mortality was observed for both control groups receiving either L.rff or L.psb. Additionally, the PAO1 lung clearance was significantly enhanced at 24 h. A 2-log and 4-log reduction was observed in the L.rff + PAO1 and L.psb + PAO1 groups respectively, compared to the control PAO1 group. Significant reductions in neutrophil recruitment and proinflammatory cytokine and chemokine secretion were observed after lactobacilli administration compared to saline solution, whereas IL-10 production was increased. Conclusions These results demonstrate that intranasal priming with lactobacilli acts as a prophylaxis, and avoids fatal complications caused by Pseudomonas aeruginosa pneumonia in mice. These results were independent of in vitro anti-Pseudomonas aeruginosa activity on QS-dependent virulence factors. Further experiments are required to identify the immune mechanism before initiating clinical trials. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-021-02254-7.
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Affiliation(s)
- Marie-Sarah Fangous
- Laboratoire de biologie médicale, Centre Hospitalier de Cornouaille, Quimper, France.,Univ Brest, Inserm, EFS, UMR 1078, GGB, Brest, France
| | - Philippe Gosset
- University of Lille, CNRS UMR9017, Inserm U1019, CHRU Lille, Institut Pasteur de Lille, CIIL - Center for Infection and Immunity of Lille- OpInfIELD, Lille, France
| | | | | | | | - Christopher Payan
- Univ Brest, Inserm, EFS, UMR 1078, GGB, Brest, France.,Département de Bactériologie-Virologie, Hygiène hospitalière et Parasitologie-Mycologie, CHRU La Cavale Blanche, Brest, France
| | - Sophie Vallet
- Univ Brest, Inserm, EFS, UMR 1078, GGB, Brest, France.,Département de Bactériologie-Virologie, Hygiène hospitalière et Parasitologie-Mycologie, CHRU La Cavale Blanche, Brest, France
| | - Geneviève Héry-Arnaud
- Univ Brest, Inserm, EFS, UMR 1078, GGB, Brest, France.,Département de Bactériologie-Virologie, Hygiène hospitalière et Parasitologie-Mycologie, CHRU La Cavale Blanche, Brest, France
| | - Rozenn Le Berre
- Univ Brest, Inserm, EFS, UMR 1078, GGB, Brest, France. .,Département de Médecine Interne et Pneumologie, CHRU La Cavale Blanche, Brest, France.
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15
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Gupte A, Jyot J, Ravi M, Ramphal R. High pyocyanin production and non-motility of Pseudomonas aeruginosa isolates are correlated with septic shock or death in bacteremic patients. PLoS One 2021; 16:e0253259. [PMID: 34115807 PMCID: PMC8195364 DOI: 10.1371/journal.pone.0253259] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 06/01/2021] [Indexed: 12/26/2022] Open
Abstract
Studies of the outcome of Pseudomonas aeruginosa bacteremia (Pab) have focused mainly on antibiotic appropriateness. However, P. aeruginosa possesses many virulence factors whose roles in outcomes have not been examined in humans, except for the type III secretion system (T3SS) toxins. The purpose of this study was to examine the role of virulence factors other than the T3SS toxins. Bacterial isolates were collected from 75 patients who suffered from Pa blood stream infections. Host factors such as neutropenia, immunosuppression, comorbidities, time to effective antibiotics, source of bacteremia, and presence of multidrug resistant (MDR) isolate were studied. The isolates were analyzed for the presence of toxin genes, proteolytic activity, swimming and twitching motility, and pyocyanin production. The data were analyzed to ascertain which virulence factors correlated with poor outcomes defined as septic shock or death (SS) within 7 days. Septic shock or death occurred in 25/75 patients. Univariate analysis identified age as a host factor that exerted a significant effect on these outcomes. Ineffective antibiotics administered during the first 24 hours of treatment or MDR P. aeruginosa did not influence the frequency of SS, nor did the presence of lasB, exoA, exoS exoU, plcH genes and proteolytic activity. However, 6/8 patients infected with non-motile isolates, developed SS, p = 0.014 and 5/6 isolates that produced large amounts of pyocyanin (>18ug/ml), were associated with SS, p = 0.014. Multivariate analysis indicated that the odds ratio (OR) for development of SS with a non-motile isolate was 6.8, with a 95% confidence interval (CI) (1.37, 51.5), p = 0.030 and with high pyocyanin producing isolates, an OR of 16.9, 95% CI = (2.27, 360), p = .017. This study evaluating the role of microbial factors that significantly effect outcomes following Pa bloodstream infection suggests that P. aeruginosa strains showing high pyocyanin production and the lack of motility independently increase the risk of SS.
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Affiliation(s)
- Asmita Gupte
- Division of Infectious Diseases and Global Medicine, Department of Medicine, University of Florida, Gainesville, Florida, United States of America
- * E-mail: (AG); (RR)
| | - Jeevan Jyot
- Division of Infectious Diseases and Global Medicine, Department of Medicine, University of Florida, Gainesville, Florida, United States of America
- Department of Pharmaceutical Outcomes & Policy, College of Pharmacy, University of Florida, Gainesville, Florida, United States of America
| | - Malleswari Ravi
- Division of Infectious Diseases and Global Medicine, Department of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Reuben Ramphal
- Division of Infectious Diseases and Global Medicine, Department of Medicine, University of Florida, Gainesville, Florida, United States of America
- * E-mail: (AG); (RR)
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16
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Abstract
Bacterial proteases and peptidases are integral to cell physiology and stability, and their necessity in Streptococcus pneumoniae is no exception. Protein cleavage and processing mechanisms within the bacterial cell serve to ensure that the cell lives and functions in its commensal habitat and can respond to new environments presenting stressful conditions. For S. pneumoniae, the human nasopharynx is its natural habitat. In the context of virulence, movement of S. pneumoniae to the lungs, blood, or other sites can instigate responses by the bacteria that result in their proteases serving dual roles of self-protein processors and virulence factors of host protein targets.
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Affiliation(s)
- Mary E Marquart
- Department of Microbiology and Immunology, University of Mississippi Medical Center, Jackson, Mississippi USA
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17
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Hofmann L, Hirsch M, Ruthstein S. Advances in Understanding of the Copper Homeostasis in Pseudomonas aeruginosa. Int J Mol Sci 2021; 22:2050. [PMID: 33669570 PMCID: PMC7922089 DOI: 10.3390/ijms22042050] [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: 01/24/2021] [Revised: 02/10/2021] [Accepted: 02/15/2021] [Indexed: 12/12/2022] Open
Abstract
Thirty-five thousand people die as a result of more than 2.8 million antibiotic-resistant infections in the United States of America per year. Pseudomonas aeruginosa (P. aeruginosa) is classified a serious threat, the second-highest threat category of the U.S. Department of Health and Human Services. Among others, the World Health Organization (WHO) encourages the discovery and development of novel antibiotic classes with new targets and mechanisms of action without cross-resistance to existing classes. To find potential new target sites in pathogenic bacteria, such as P. aeruginosa, it is inevitable to fully understand the molecular mechanism of homeostasis, metabolism, regulation, growth, and resistances thereof. P. aeruginosa maintains a sophisticated copper defense cascade comprising three stages, resembling those of public safety organizations. These stages include copper scavenging, first responder, and second responder. Similar mechanisms are found in numerous pathogens. Here we compare the copper-dependent transcription regulators cueR and copRS of Escherichia coli (E. coli) and P. aeruginosa. Further, phylogenetic analysis and structural modelling of mexPQ-opmE reveal that this efflux pump is unlikely to be involved in the copper export of P. aeruginosa. Altogether, we present current understandings of the copper homeostasis in P. aeruginosa and potential new target sites for antimicrobial agents or a combinatorial drug regimen in the fight against multidrug resistant pathogens.
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Affiliation(s)
| | | | - Sharon Ruthstein
- Institute of Nanotechnology and Advanced Materials & Department of Chemistry, Faculty of Exact Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel; (L.H.); (M.H.)
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18
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Haque M, Islam S, Sheikh MA, Dhingra S, Uwambaye P, Labricciosa FM, Iskandar K, Charan J, Abukabda AB, Jahan D. Quorum sensing: a new prospect for the management of antimicrobial-resistant infectious diseases. Expert Rev Anti Infect Ther 2020; 19:571-586. [PMID: 33131352 DOI: 10.1080/14787210.2021.1843427] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
INTRODUCTION Quorum-sensing (QS) is a microbial cell-to-cell communication system that utilizes small signaling molecules to mediates interactions between cross-kingdom microorganisms, including Gram-positive and -negative microbes. QS molecules include N-acyl-homoserine-lactones (AHLs), furanosyl borate, hydroxyl-palmitic acid methylester, and methyl-dodecanoic acid. These signaling molecules maintain the symbiotic relationship between a host and the healthy microbial flora and also control various microbial virulence factors. This manuscript has been developed based on published scientific papers. AREAS COVERED Furanones, glycosylated chemicals, heavy metals, and nanomaterials are considered QS inhibitors (QSIs) and are therefore capable of inhibiting the microbial QS system. QSIs are currently being considered as antimicrobial therapeutic options. Currently, the low speed at which new antimicrobial agents are being developed impairs the treatment of drug-resistant infections. Therefore, QSIs are currently being studied as potential interventions targeting QS-signaling molecules and quorum quenching (QQ) enzymes to reduce microbial virulence. EXPERT OPINION QSIs represent a novel opportunity to combat antimicrobial resistance (AMR). However, no clinical trials have been conducted thus far assessing their efficacy. With the recent advancements in technology and the development of well-designed clinical trials aimed at targeting various components of the, QS system, these agents will undoubtedly provide a useful alternative to treat infectious diseases.
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Affiliation(s)
- Mainul Haque
- Faculty of Medicine and Defence Health, Universiti Pertahanan Nasional Malaysia (National Defence University of Malaysia), Kuala Lumpur, Malaysia
| | - Salequl Islam
- Department of Microbiology, Jahangirnagar University, Savar, Dhaka, Bangladesh
| | | | - Sameer Dhingra
- School of Pharmacy, Faculty of Medical Sciences, The University of the West Indies, St. Augustine Campus, Eric Williams Medical Sciences Complex, Trinidad & Tobago
| | - Peace Uwambaye
- Department of Preventive & Community Dentistry, University of Rwanda College of Medicine and Health Sciences, School of Dentistry, Kigali, Rwanda
| | | | - Katia Iskandar
- Department of Mathématiques Informatique et Télécommunications, Université Toulouse III, Paul Sabatier, INSERM, UMR 1027, F-31000 Toulouse, France.,INSPECT-LB: Institut National de Santé Publique, d'Épidémiologie Clinique et de Toxicologie-Liban, Beirut 6573-14, Lebanon.,Faculty of Pharmacy, Lebanese University, Beirut 1106, Lebanon
| | - Jaykaran Charan
- Department of Pharmacology, All India Institute of Medical Sciences, Jodhpur, Rajasthan, India
| | | | - Dilshad Jahan
- Department of Hematology, Asgar Ali Hospital, Dhaka, Bangladesh
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Recio R, Mancheño M, Viedma E, Villa J, Orellana MÁ, Lora-Tamayo J, Chaves F. Predictors of Mortality in Bloodstream Infections Caused by Pseudomonas aeruginosa and Impact of Antimicrobial Resistance and Bacterial Virulence. Antimicrob Agents Chemother 2020; 64:e01759-19. [PMID: 31767719 PMCID: PMC6985728 DOI: 10.1128/aac.01759-19] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 11/11/2019] [Indexed: 12/26/2022] Open
Abstract
Whether multidrug resistance (MDR) is associated with mortality in patients with Pseudomonas aeruginosa bloodstream infections (BSI) remains controversial. Here, we explored the prognostic factors of P. aeruginosa BSI with emphasis on antimicrobial resistance and virulence. All P. aeruginosa BSI episodes in a 5-year period were retrospectively analyzed. The impact in early (5-day) and late (30-day) crude mortality of host, antibiotic treatment, and pathogen factors was assessed by multivariate logistic regression analysis. Of 243 episodes, 93 (38.3%) were caused by MDR-PA. Crude 5-day (20%) and 30-day (33%) mortality was more frequent in patients with MDR-PA (34.4% versus 11.3%, P < 0.001 and 52.7% versus 21.3%, P < 0.001, respectively). Early mortality was associated with neutropenia (adjusted odds ratio [aOR], 9.21; 95% confidence interval [CI], 3.40 to 24.9; P < 0.001), increased Pitt score (aOR, 2.42; 95% CI, 1.34 to 4.36; P = 0.003), respiratory source (aOR, 3.23; 95% CI,2.01 to 5.16; P < 0.001), inadequate empirical therapy (aOR, 4.57; 95% CI, 1.59 to 13.1; P = 0.005), shorter time to positivity of blood culture (aOR, 0.88; 95% CI, 0.80 to 0.97; P = 0.010), an exoU-positive genotype (aOR, 3.58; 95% CI, 1.31 to 9.79; P = 0.013), and the O11 serotype (aOR, 3.64; 95% CI, 1.20 to 11.1; P = 0.022). These risk factors were similarly identified for late mortality, along with an MDR phenotype (aOR, 2.18; 95% CI, 1.04 to 4.58; P = 0.040). Moreover, the O11 serotype (15.2%, 37/243) was common among MDR (78.4%, 29/37) and exoU-positive (89.2%, 33/37) strains. Besides relevant clinical variables and inadequate empirical therapy, pathogen-related factors such as an MDR phenotype, an exoU-positive genotype, and the O11 serotype adversely affect the outcome of P. aeruginosa BSI.
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Affiliation(s)
- Raúl Recio
- Department of Clinical Microbiology, Instituto de Investigación Hospital 12 de Octubre (i+12), Hospital Universitario 12 de Octubre, Madrid, Spain
| | - Mikel Mancheño
- Department of Internal Medicine, Instituto de Investigación Hospital 12 de Octubre (i+12), Hospital Universitario 12 de Octubre, Madrid, Spain
| | - Esther Viedma
- Department of Clinical Microbiology, Instituto de Investigación Hospital 12 de Octubre (i+12), Hospital Universitario 12 de Octubre, Madrid, Spain
| | - Jennifer Villa
- Department of Clinical Microbiology, Instituto de Investigación Hospital 12 de Octubre (i+12), Hospital Universitario 12 de Octubre, Madrid, Spain
| | - María Ángeles Orellana
- Department of Clinical Microbiology, Instituto de Investigación Hospital 12 de Octubre (i+12), Hospital Universitario 12 de Octubre, Madrid, Spain
| | - Jaime Lora-Tamayo
- Department of Internal Medicine, Instituto de Investigación Hospital 12 de Octubre (i+12), Hospital Universitario 12 de Octubre, Madrid, Spain
| | - Fernando Chaves
- Department of Clinical Microbiology, Instituto de Investigación Hospital 12 de Octubre (i+12), Hospital Universitario 12 de Octubre, Madrid, Spain
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Montagna MT, Triggiano F, Barbuti G, Bartolomeo N, De Giglio O, Diella G, Lopuzzo M, Rutigliano S, Serio G, Caggiano G. Study on the In Vitro Activity of Five Disinfectants against Nosocomial Bacteria. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:E1895. [PMID: 31146343 PMCID: PMC6603693 DOI: 10.3390/ijerph16111895] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 05/25/2019] [Accepted: 05/27/2019] [Indexed: 01/12/2023]
Abstract
Nosocomial infections cause significant morbidity and mortality worldwide, and the pathogenic organisms responsible for such infections can develop resistance to antimicrobial agents. Understanding the activity of disinfectants against clinical and environmental bacterial isolates is therefore crucial. We analysed the in vitro activity of five antimicrobial products (phenolic compounds, didecyldimethylammonium chloride (DDAC), sodium hypochlorite, isopropanol + ammonium compounds (IACs), hydrogen peroxide) against 187 bacterial strains comprising clinical isolates, as well as 30 environmental isolates of Pseudomonas aeruginosa from hospital water samples. Disk diffusion assays were employed to assess antimicrobial activity. Hydrogen peroxide was significantly more active (p < 0.0001) than the other disinfectants against all P. aeruginosa, Klebsiella pneumoniae, Enterococcus faecalis and Staphylococcus aureus strains. It was also the only disinfectant with activity against both clinical and environmental strains of P. aeruginosa. DDAC and IAC-based disinfectants were ineffective against Gram-negative strains, but showed significant activity (particularly IACs, p < 0.0001) against the Gram-positive strains. Compared with IACs, DDAC was significantly more active on E. faecalis and less active on S. aureus (p < 0.0001). Sodium hypochlorite and phenol compounds, by contrast, were inactive against all bacterial strains. The development of disinfection procedures that are effective against all microorganisms is essential for limiting the spread of nosocomial infections.
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Affiliation(s)
- Maria Teresa Montagna
- Department of Biomedical Science and Human Oncology, University of Bari "Aldo Moro", Piazza G. Cesare 11, 70124 Bari, Italy.
| | - Francesco Triggiano
- Department of Biomedical Science and Human Oncology, University of Bari "Aldo Moro", Piazza G. Cesare 11, 70124 Bari, Italy.
| | - Giovanna Barbuti
- Department of Biomedical Science and Human Oncology, University of Bari "Aldo Moro", Piazza G. Cesare 11, 70124 Bari, Italy.
| | - Nicola Bartolomeo
- Department of Biomedical Science and Human Oncology, University of Bari "Aldo Moro", Piazza G. Cesare 11, 70124 Bari, Italy.
| | - Osvalda De Giglio
- Department of Biomedical Science and Human Oncology, University of Bari "Aldo Moro", Piazza G. Cesare 11, 70124 Bari, Italy.
| | - Giusy Diella
- Department of Biomedical Science and Human Oncology, University of Bari "Aldo Moro", Piazza G. Cesare 11, 70124 Bari, Italy.
| | - Marco Lopuzzo
- Department of Biomedical Science and Human Oncology, University of Bari "Aldo Moro", Piazza G. Cesare 11, 70124 Bari, Italy.
| | - Serafina Rutigliano
- Department of Biomedical Science and Human Oncology, University of Bari "Aldo Moro", Piazza G. Cesare 11, 70124 Bari, Italy.
| | - Gabriella Serio
- Department of Biomedical Science and Human Oncology, University of Bari "Aldo Moro", Piazza G. Cesare 11, 70124 Bari, Italy.
| | - Giuseppina Caggiano
- Department of Biomedical Science and Human Oncology, University of Bari "Aldo Moro", Piazza G. Cesare 11, 70124 Bari, Italy.
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Tang A, Caballero AR, Marquart ME, Bierdeman MA, O'Callaghan RJ. Mechanism of Pseudomonas aeruginosa Small Protease (PASP), a Corneal Virulence Factor. Invest Ophthalmol Vis Sci 2019; 59:5993-6002. [PMID: 30572344 PMCID: PMC6306078 DOI: 10.1167/iovs.18-25834] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Pseudomonas aeruginosa is the leading cause of contact lens-associated bacterial keratitis. Secreted bacterial proteases have a key role in keratitis, including the P. aeruginosa small protease (PASP), a proven corneal virulence factor. We investigated the mechanism of PASP and its importance to corneal toxicity. Methods PASP, a serine protease, was tested for activity on various substrates. The catalytic triad of PASP was sought by bioinformatic analysis and site-directed mutagenesis. All mutant constructs were expressed in a P. aeruginosa PASP-deficient strain; the resulting proteins were purified using ion-exchange, gel filtration, or affinity chromatography; and the proteolytic activity was assessed by gelatin zymography and a fluorometric assay. The purified PASP proteins with single amino acid changes were injected into rabbit corneas to determine their pathological effects. Results PASP substrates were cleaved at arginine or lysine residues. Alanine substitution of PASP residues Asp-29, His-34, or Ser-47 eliminated protease activity, whereas PASP with substitution for Ser-59 (control) retained activity. Computer modeling and Western blot analysis indicated that formation of a catalytic triad required dimer formation, and zymography demonstrated the protease activity of the homodimer, but not the monomer. PASP with the Ser-47 mutation, but not with the control mutation, lacked corneal toxicity, indicating the importance of protease activity. Conclusions PASP is a secreted serine protease that can cleave proteins at arginine or lysine residues and PASP activity requires dimer or larger aggregates to create a functional active site. Most importantly, proteolytic PASP molecules demonstrated highly significant toxicity for the rabbit cornea.
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Affiliation(s)
- Aihua Tang
- Department of Microbiology and Immunology, University of Mississippi Medical Center, Jackson, Mississippi, United States
| | - Armando R Caballero
- Department of Microbiology and Immunology, University of Mississippi Medical Center, Jackson, Mississippi, United States
| | - Mary E Marquart
- Department of Microbiology and Immunology, University of Mississippi Medical Center, Jackson, Mississippi, United States
| | - Michael A Bierdeman
- Department of Microbiology and Immunology, University of Mississippi Medical Center, Jackson, Mississippi, United States
| | - Richard J O'Callaghan
- Department of Microbiology and Immunology, University of Mississippi Medical Center, Jackson, Mississippi, United States
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Jiang Q, Chen J, Yang C, Yin Y, Yao K. Quorum Sensing: A Prospective Therapeutic Target for Bacterial Diseases. BIOMED RESEARCH INTERNATIONAL 2019; 2019:2015978. [PMID: 31080810 PMCID: PMC6475571 DOI: 10.1155/2019/2015978] [Citation(s) in RCA: 150] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 03/20/2019] [Indexed: 01/07/2023]
Abstract
Bacterial quorum sensing (QS) is a cell-to-cell communication in which specific signals are activated to coordinate pathogenic behaviors and help bacteria acclimatize to the disadvantages. The QS signals in the bacteria mainly consist of acyl-homoserine lactone, autoinducing peptide, and autoinducer-2. QS signaling activation and biofilm formation lead to the antimicrobial resistance of the pathogens, thus increasing the therapy difficulty of bacterial diseases. Anti-QS agents can abolish the QS signaling and prevent the biofilm formation, therefore reducing bacterial virulence without causing drug-resistant to the pathogens, suggesting that anti-QS agents are potential alternatives for antibiotics. This review focuses on the anti-QS agents and their mediated signals in the pathogens and conveys the potential of QS targeted therapy for bacterial diseases.
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Affiliation(s)
- Qian Jiang
- Laboratory of Animal Nutritional Physiology and Metabolic Process, Institute of Subtropical Agriculture, Chinese Academy of Sciences, China
- University of Chinese Academy of Sciences, Beijing 100043, China
- Department of Animal Science, University of Manitoba, Winnipeg, MB, Canada R3T 2N2
| | - Jiashun Chen
- Laboratory of Animal Nutritional Physiology and Metabolic Process, Institute of Subtropical Agriculture, Chinese Academy of Sciences, China
| | - Chengbo Yang
- Department of Animal Science, University of Manitoba, Winnipeg, MB, Canada R3T 2N2
| | - Yulong Yin
- Laboratory of Animal Nutritional Physiology and Metabolic Process, Institute of Subtropical Agriculture, Chinese Academy of Sciences, China
| | - Kang Yao
- Laboratory of Animal Nutritional Physiology and Metabolic Process, Institute of Subtropical Agriculture, Chinese Academy of Sciences, China
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Britt NS, Ritchie DJ, Kollef MH, Burnham CAD, Durkin MJ, Hampton NB, Micek ST. Clinical epidemiology of carbapenem-resistant gram-negative sepsis among hospitalized patients: Shifting burden of disease? Am J Infect Control 2018; 46:1092-1096. [PMID: 29706365 DOI: 10.1016/j.ajic.2018.03.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 03/13/2018] [Accepted: 03/13/2018] [Indexed: 01/10/2023]
Abstract
BACKGROUND Infections caused by carbapenem-resistant gram-negative bacilli are an emerging public health threat. However, there is a paucity of data examining comparative incidence rates, risk factors, and outcomes in this population. METHODS This single-center retrospective cohort study was conducted at an urban tertiary-care academic medical center. We included patients admitted from 2012 to 2015 who met the following criteria: i) age ≥ 18 years; and ii) culture positive for carbapenem-resistant Enterobacteriaceae (CRE) or carbapenem-resistant non-Enterobacteriaceae (CRNE) from any site. Exclusion criteria were: i) < 2 systemic inflammatory response criteria; ii) cystic fibrosis; and iii) no targeted treatment. We evaluated hospital survival by Cox regression and year-by-year differences in the distribution of cases by the Cochran-Armitage test. RESULTS 448 patients were analyzed (CRE, n = 111 [24.8%]; CRNE, n = 337 [75.2%]). CRE sepsis cases increased significantly over the study period (P <.001), driven primarily by increasing incidence of Enterobacter spp. infection (P = .004). No difference was observed in hospital survival between patients with CRE versus CRNE sepsis (hazard ratio [HR], 1.29; 95% confidence interval [CI], 0.83-2.02; P = .285), even after adjusting for confounding factors (adjusted HR, 1.08; 95% CI, 0.62-1.87; P = .799). CONCLUSIONS Clinical outcomes did not differ between patients with CRE versus CRNE sepsis. Dramatic increases in CRE, particularly Enterobacter spp., appear to be causing a shift in the burden of clinically significant carbapenem-resistant gram-negative infection.
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Saputra IWAGM, Mertaniasih NM, Fatmawati NND. Positivity of ExoU Gene of Type III Secretion System and Fluoroquinolone Resistance of Psedomonas aeruginosa from Sputum of Nosocomial Pneumonia Patients in Sanglah Hospital, Bali. FOLIA MEDICA INDONESIANA 2018. [DOI: 10.20473/fmi.v54i2.8863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Pseudomonas aeruginosa is one of the Gram-negative rods bacteria that frequently cause nosocomial pneumonia. One of the main virulent effector proteins on Type III secretion system (TTSS) of P. aeruginosa is Exoenzyme U ( ExoU). ExoU works as a phospholipase A2 activity and exhibits lung tissue injury effect in pneumonia. As an antibiotic that has activity against P. aeruginosa, fluoroquinolone resistance has increased as many as three fold since the last decade. Infections caused by P. aeruginosa that are fluoroquinolone resistant and positive for ExoU gene show worse clinical outcome. The aim of this study was to determine the positivity of ExoU gene TTSS and fluoroquinolone resistance of P. aeruginosa that isolated from sputum of nosocomial pneumonia patients in Sanglah Hospital, Bali. P. aeruginosa isolated from sputum of patient that diagnosed as nosocomial pneumonia, isolates had been identified phenotypically by Vitek2 Compact system (bioMérieux, Inc., Marcy-l'Etoile - France), and then continued by genotypic detection by PCR. The susceptibility testing of P. aeruginosa isolates to Ciprofloxacin were conducted by Vitek2 Compact, whereas ExoU genes were detected by PCR. Fifty-three P. aeruginosa isolates were identified in this study, in which 35 isolates (66.1%) had ExoU gene and 22 isolates (41.5%) were resistant to Ciprofloxacin. Based on nosocomial pneumonia type, the highest proportion of isolates genotipically ExoU+ and phenotypically Ciprofloxacin were on VAP group accounted for 57.1% and 54.5%, respectively. Chi-square analysis showed significant correlation between Ciprofloxacin resistance and ExoU gene (p=0.001). As a conclusion, the positivity of ExoU+ isolates were more likely found in Ciprofloxacin resistant group.
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MEDI3902 Correlates of Protection against Severe Pseudomonas aeruginosa Pneumonia in a Rabbit Acute Pneumonia Model. Antimicrob Agents Chemother 2018; 62:AAC.02565-17. [PMID: 29483116 PMCID: PMC5923159 DOI: 10.1128/aac.02565-17] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 02/20/2018] [Indexed: 12/24/2022] Open
Abstract
Pseudomonas aeruginosa is among the most formidable antibiotic-resistant pathogens and is a leading cause of hospital-associated infections. With dwindling options for antibiotic-resistant infections, a new paradigm for treatment and disease resolution is required. MEDI3902, a bispecific antibody targeting the P. aeruginosa type III secretion (T3S) protein PcrV and Psl exopolysaccharide, was previously shown to mediate potent protective activity in murine infection models. With the current challenges associated with the clinical development of narrow-spectrum agents, robust preclinical efficacy data in multiple animal species are desirable. Here, we sought to develop a rabbit P. aeruginosa acute pneumonia model to further evaluate the activity of MEDI3902 intervention. In the rabbit model of acute pneumonia, prophylaxis with MEDI3902 exhibited potent dose-dependent protection, whereas those receiving control IgG developed fatal hemorrhagic necrotizing pneumonia between 12 and 54 h after infection. Blood biomarkers (e.g., partial pressure of oxygen [pO2], partial pressure of carbon dioxide [pCO2], base excess, lactate, and creatinine) were grossly deranged for the vast majority of control IgG-treated animals but remained within normal limits for MEDI3902-treated animals. In addition, MEDI3902-treated animals exhibited a profound reduction in P. aeruginosa organ burden and a marked reduction in the expression of proinflammatory mediators from lung tissue, which correlated with reduced lung histopathology. These results confirm that targeting PcrV and Psl via MEDI3902 is a promising candidate for immunotherapy against P. aeruginosa pneumonia.
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Qu Y, Olonisakin T, Bain W, Zupetic J, Brown R, Hulver M, Xiong Z, Tejero J, Shanks RM, Bomberger JM, Cooper VS, Zegans ME, Ryu H, Han J, Pilewski J, Ray A, Cheng Z, Ray P, Lee JS. Thrombospondin-1 protects against pathogen-induced lung injury by limiting extracellular matrix proteolysis. JCI Insight 2018; 3:96914. [PMID: 29415890 PMCID: PMC5821195 DOI: 10.1172/jci.insight.96914] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 12/27/2017] [Indexed: 12/29/2022] Open
Abstract
Acute lung injury is characterized by excessive extracellular matrix proteolysis and neutrophilic inflammation. A major risk factor for lung injury is bacterial pneumonia. However, host factors that protect against pathogen-induced and host-sustained proteolytic injury following infection are poorly understood. Pseudomonas aeruginosa (PA) is a major cause of nosocomial pneumonia and secretes proteases to amplify tissue injury. We show that thrombospondin-1 (TSP-1), a matricellular glycoprotein released during inflammation, dose-dependently inhibits PA metalloendoprotease LasB, a virulence factor. TSP-1-deficient (Thbs1-/-) mice show reduced survival, impaired host defense, and increased lung permeability with exaggerated neutrophil activation following acute intrapulmonary PA infection. Administration of TSP-1 from platelets corrects the impaired host defense and aberrant injury in Thbs1-/- mice. Although TSP-1 is cleaved into 2 fragments by PA, TSP-1 substantially inhibits Pseudomonas elastolytic activity. Administration of LasB inhibitor, genetic disabling of the PA type II secretion system, or functional deletion of LasB improves host defense and neutrophilic inflammation in mice. Moreover, TSP-1 provides an additional line of defense by directly subduing host-derived proteolysis, with dose-dependent inhibition of neutrophil elastase from airway neutrophils of mechanically ventilated critically ill patients. Thus, a host matricellular protein provides dual levels of protection against pathogen-initiated and host-sustained proteolytic injury following microbial trigger.
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Affiliation(s)
- Yanyan Qu
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine
| | - Tolani Olonisakin
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine
| | - William Bain
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine
| | - Jill Zupetic
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine
| | - Rebecca Brown
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine
| | - Mei Hulver
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine
| | - Zeyu Xiong
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine
| | - Jesus Tejero
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine
- Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Robert M.Q. Shanks
- Department of Ophthalmology, and
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Jennifer M. Bomberger
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Vaughn S. Cooper
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Michael E. Zegans
- Department of Microbiology and Immunology, Dartmouth Geisel School of Medicine, Hanover, New Hampshire, USA
| | | | - Jongyoon Han
- Research Laboratory of Electronics
- Department of Electrical Engineering and Computer Science, and
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Joseph Pilewski
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine
| | - Anuradha Ray
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine
| | - Zhenyu Cheng
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Prabir Ray
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine
| | - Janet S. Lee
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine
- Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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Hvorecny KL, Dolben E, Moreau-Marquis S, Hampton TH, Shabaneh TB, Flitter BA, Bahl CD, Bomberger JM, Levy BD, Stanton BA, Hogan DA, Madden DR. An epoxide hydrolase secreted by Pseudomonas aeruginosa decreases mucociliary transport and hinders bacterial clearance from the lung. Am J Physiol Lung Cell Mol Physiol 2017; 314:L150-L156. [PMID: 28982736 DOI: 10.1152/ajplung.00383.2017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The opportunistic pathogen Pseudomonas aeruginosa colonizes the lungs of susceptible individuals by deploying virulence factors targeting host defenses. The secreted factor Cif (cystic fibrosis transmembrane conductance regulator inhibitory factor) dysregulates the endocytic recycling of CFTR and thus reduces CFTR abundance in host epithelial membranes. We have postulated that the decrease in ion secretion mediated by Cif would slow mucociliary transport and decrease bacterial clearance from the lungs. To test this hypothesis, we explored the effects of Cif in cultured epithelia and in the lungs of mice. We developed a strategy to interpret the "hurricane-like" motions observed in reconstituted cultures and identified a Cif-mediated decrease in the velocity of mucus transport in vitro. Presence of Cif also increased the number of bacteria recovered at two time points in an acute mouse model of pneumonia caused by P. aeruginosa. Furthermore, recent work has demonstrated an inverse correlation between the airway concentrations of Cif and 15-epi-lipoxin A4, a proresolving lipid mediator important in host defense and the resolution of pathogen-initiated inflammation. Here, we observe elevated levels of 15-epi-lipoxin A4 in the lungs of mice infected with a strain of P. aeruginosa that expresses only an inactive form of cif compared with those mice infected with wild-type P. aeruginosa. Together these data support the inclusion of Cif on the list of virulence factors that assist P. aeruginosa in colonizing and damaging the airways of compromised patients. Furthermore, this study establishes techniques that enable our groups to explore the underlying mechanisms of Cif effects during respiratory infection.
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Affiliation(s)
- Kelli L Hvorecny
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth , Hanover, New Hampshire
| | - Emily Dolben
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth , Hanover, New Hampshire
| | - Sophie Moreau-Marquis
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth , Hanover, New Hampshire
| | - Thomas H Hampton
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth , Hanover, New Hampshire
| | - Tamer B Shabaneh
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth , Hanover, New Hampshire
| | - Becca A Flitter
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine , Pittsburgh, Pennsylvania
| | - Christopher D Bahl
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth , Hanover, New Hampshire
| | - Jennifer M Bomberger
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine , Pittsburgh, Pennsylvania
| | - Bruce D Levy
- Department of Internal Medicine, Pulmonary and Critical Care Medicine, Brigham and Women's Hospital, Harvard Medical School , Boston, Massachusetts
| | - Bruce A Stanton
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth , Hanover, New Hampshire
| | - Deborah A Hogan
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth , Hanover, New Hampshire
| | - Dean R Madden
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth , Hanover, New Hampshire
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Pseudomonas aeruginosa Exolysin promotes bacterial growth in lungs, alveolar damage and bacterial dissemination. Sci Rep 2017; 7:2120. [PMID: 28522850 PMCID: PMC5437091 DOI: 10.1038/s41598-017-02349-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 04/10/2017] [Indexed: 11/18/2022] Open
Abstract
Exolysin (ExlA) is a recently-identified pore-forming toxin secreted by a subset of Pseudomonas aeruginosa strains identified worldwide and devoid of Type III secretion system (T3SS), a major virulence factor. Here, we characterized at the ultrastructural level the lesions caused by an ExlA-secreting strain, CLJ1, in mouse infected lungs. CLJ1 induced necrotic lesions in pneumocytes and endothelial cells, resulting in alveolo-vascular barrier breakdown. Ectopic expression of ExlA in an exlA-negative strain induced similar tissue injuries. In addition, ExlA conferred on bacteria the capacity to proliferate in lungs and to disseminate in secondary organs, similar to bacteria possessing a functional T3SS. CLJ1 did not promote a strong neutrophil infiltration in the alveoli, owing to the weak pro-inflammatory cytokine reaction engendered by the strain. However, CLJ1 was rapidly eliminated from the blood in a bacteremia model, suggesting that it can be promptly phagocytosed by immune cells. Together, our study ascribes to ExlA-secreting bacteria the capacity to proliferate in the lung and to damage pulmonary tissues, thereby promoting metastatic infections, in absence of substantial immune response exacerbation.
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Cendra MDM, Christodoulides M, Hossain P. Signaling Mediated by Toll- Like Receptor 5 Sensing of Pseudomonas aeruginosa Flagellin Influences IL-1β and IL-18 Production by Primary Fibroblasts Derived from the Human Cornea. Front Cell Infect Microbiol 2017; 7:130. [PMID: 28469996 PMCID: PMC5395653 DOI: 10.3389/fcimb.2017.00130] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 03/29/2017] [Indexed: 12/24/2022] Open
Abstract
Pseudomonas aeruginosa is the principal cause of bacterial keratitis worldwide and overstimulation of the innate immune system by this organism is believed to contribute significantly to sight loss. In the current study, we have used primary human corneal fibroblast (hCF) cells as an ex vivo model of corneal infection to examine the role of P. aeruginosa flagellum and type three secretion system (TTSS) in inducing inflammasome-associated molecules that trigger IL-1β and IL-18 production during the early stages of the infection. Our results show that P. aeruginosa infection stimulated the non-canonical pathway for IL-1β and IL-18 expression and pathway stimulation was influenced predominantly by the flagellum. Both IL-1β and IL-18 cytokines were expressed intracellularly during bacterial infection, but only the former was released and detected in the extracellular environment. We also investigated the signaling pathways in hCFs mediated by Toll-Like Receptor (TLR)4 and TLR5 sensing of P. aeruginosa, and our data show that the signal triggered by TLR5-flagellin sensing significantly contributed to IL-1β and IL-18 cytokine production in our model. Our study suggests that IL-18 expression is wholly dependent on extracellular flagellin sensing by TLR5, whereas IL-1β expression is also influenced by P. aeruginosa lipopolysacharide. Additionally, we demonstrate that IL-1β and IL-18 production by hCFs can be triggered by both MyD88-dependent and -independent pathways. Overall, our study provides a rationale for the development of targeted therapies, by proposing an inhibition of flagellin-PRR-signaling interactions, in order to ameliorate the inflammatory response characteristic of P. aeruginosa keratitis.
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Affiliation(s)
- Maria Del Mar Cendra
- Division of Clinical and Experimental Sciences, Department of Molecular Microbiology, Faculty of Medicine, University of SouthamptonSouthampton, UK
| | - Myron Christodoulides
- Division of Clinical and Experimental Sciences, Department of Molecular Microbiology, Faculty of Medicine, University of SouthamptonSouthampton, UK
| | - Parwez Hossain
- Eye Unit, Division of Clinical and Experimental Sciences, Faculty of Medicine, University of SouthamptonSouthampton, UK
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Benie CKD, Dadié A, Guessennd N, N'gbesso-Kouadio NA, Kouame ND, N'golo DC, Aka S, Dako E, Dje KM, Dosso M. Characterization of Virulence Potential of Pseudomonas Aeruginosa Isolated from Bovine Meat, Fresh Fish, and Smoked Fish. Eur J Microbiol Immunol (Bp) 2017; 7:55-64. [PMID: 28386471 PMCID: PMC5372481 DOI: 10.1556/1886.2016.00039] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 01/12/2017] [Indexed: 11/19/2022] Open
Abstract
Pseudomonas aeruginosa owns a variability of virulence factors. These factors can increase bacterial pathogenicity and infection severity. Despite the importance of knowledge about them, these factors are not more characterized at level of strains derived from local food products. This study aimed to characterize the virulence potential of P. aeruginosa isolated from various animal products. Several structural and virulence genes of P. aeruginosa including lasB, exoS, algD, plcH, pilB, exoU, and nan1 were detected by polymerase chain reaction (PCR) on 204 strains of P. aeruginosa. They were isolated from bovine meat (122), fresh fish (49), and smoked fish (33). The 16S rRNA gene was detected on 91.1% of the presumptive strains as Pseudomonas. The rpoB gene showed that 99.5% of the strains were P. aeruginosa. The lasB gene (89.2%) was the most frequently detected (p < 0.05). In decreasing importance order, exoS (86.8%), algD (72.1%), plcH (72.1%), pilB (40.2%), and exoU (2.5%) were detected. The lasB gene was detected in all strains of P. aeruginosa serogroups O11 and O16. The prevalence of algD, exoS, and exoU genes in these strains varied from 51.2% to 87.4%. The simultaneous determination of serogroups and virulence factors is of interest for the efficacy of surveillance of infections associated with P. aeruginosa.
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Affiliation(s)
- Comoé Koffi Donatien Benie
- Laboratory of Biotechnology and Food Microbiology (LMBM), University of Nangui-Abrogoua, 02 BP 801, Abidjan 02, Côte d'Ivoire; Department of Bacteriology and Virology, Institut Pasteur of Côte d'Ivoire (IPCI), 01 BP 490, Abidjan 01, Côte d'Ivoire
| | - Adjéhi Dadié
- Laboratory of Biotechnology and Food Microbiology (LMBM), University of Nangui-Abrogoua, 02 BP 801, Abidjan 02, Côte d'Ivoire; Department of Bacteriology and Virology, Institut Pasteur of Côte d'Ivoire (IPCI), 01 BP 490, Abidjan 01, Côte d'Ivoire
| | - Nathalie Guessennd
- Department of Bacteriology and Virology, Institut Pasteur of Côte d'Ivoire (IPCI), 01 BP 490, Abidjan 01, Côte d'Ivoire; Faculty of Medical Sciences, University of Félix Houphouët Boigny, 01 BP V4, Abidjan 01, Côte d'Ivoire
| | - Nadège Ahou N'gbesso-Kouadio
- Laboratory of Biotechnology and Food Microbiology (LMBM), University of Nangui-Abrogoua , 02 BP 801, Abidjan 02, Côte d'Ivoire
| | - N'zebo Désiré Kouame
- Laboratory of Biotechnology and Food Microbiology (LMBM), University of Nangui-Abrogoua , 02 BP 801, Abidjan 02, Côte d'Ivoire
| | - David Coulibaly N'golo
- Department of Bacteriology and Virology, Institut Pasteur of Côte d'Ivoire (IPCI) , 01 BP 490, Abidjan 01, Côte d'Ivoire
| | - Solange Aka
- Laboratory of Biotechnology and Food Microbiology (LMBM), University of Nangui-Abrogoua , 02 BP 801, Abidjan 02, Côte d'Ivoire
| | - Etienne Dako
- School of Food Science, Nutrition and Family Studies Faculty of Health Sciences and Community Services, University of Moncton, Moncton , NB E1A 3E9, Canada
| | - Koffi Marcellin Dje
- Laboratory of Biotechnology and Food Microbiology (LMBM), University of Nangui-Abrogoua , 02 BP 801, Abidjan 02, Côte d'Ivoire
| | - Mireille Dosso
- Department of Bacteriology and Virology, Institut Pasteur of Côte d'Ivoire (IPCI), 01 BP 490, Abidjan 01, Côte d'Ivoire; Faculty of Medical Sciences, University of Félix Houphouët Boigny, 01 BP V4, Abidjan 01, Côte d'Ivoire
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Pseudomonas aeruginosa Pore-Forming Exolysin and Type IV Pili Cooperate To Induce Host Cell Lysis. mBio 2017; 8:mBio.02250-16. [PMID: 28119472 PMCID: PMC5263249 DOI: 10.1128/mbio.02250-16] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Clinical strains of Pseudomonas aeruginosa lacking the type III secretion system genes employ a toxin, exolysin (ExlA), for host cell membrane disruption. Here, we demonstrated that ExlA export requires a predicted outer membrane protein, ExlB, showing that ExlA and ExlB define a new active two-partner secretion (TPS) system of P. aeruginosa In addition to the TPS signals, ExlA harbors several distinct domains, which include one hemagglutinin domain, five arginine-glycine-aspartic acid (RGD) motifs, and a C-terminal region lacking any identifiable sequence motifs. However, this C-terminal region is important for the toxic activity, since its deletion abolishes host cell lysis. Using lipid vesicles and eukaryotic cells, including red blood cells, we demonstrated that ExlA has a pore-forming activity which precedes cell membrane disruption of nucleated cells. Finally, we developed a high-throughput cell-based live-dead assay and used it to screen a transposon mutant library of an ExlA-producing P. aeruginosa clinical strain for bacterial factors required for ExlA-mediated toxicity. The screen resulted in the identification of proteins involved in the formation of type IV pili as being required for ExlA to exert its cytotoxic activity by promoting close contact between bacteria and the host cell. These findings represent the first example of cooperation between a pore-forming toxin of the TPS family and surface appendages in host cell intoxication. IMPORTANCE The course and outcome of acute, toxigenic infections by Pseudomonas aeruginosa clinical isolates rely on the deployment of one of two virulence strategies: delivery of effectors by the well-known type III secretion system or the cytolytic activity of the recently identified two-partner secreted toxin, exolysin. Here, we characterize several features of the mammalian cell intoxication process mediated by exolysin. We found that exolysin requires the outer membrane protein ExlB for export into extracellular medium. Using in vitro recombinant protein and ex vivo assays, we demonstrated a pore-forming activity of exolysin. A cellular cytotoxicity screen of a transposon mutant library, made in an exolysin-producing clinical strain, identified type IV pili as bacterial appendages required for exolysin toxic function. This work deciphers molecular mechanisms underlying the activity of novel virulence factors used by P. aeruginosa clinical strains lacking the type III secretion system, including a requirement for the toxin-producing bacteria to be attached to the targeted cell to induce cytolysis, and defines new targets for developing antivirulence strategies.
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Reboud E, Elsen S, Bouillot S, Golovkine G, Basso P, Jeannot K, Attrée I, Huber P. Phenotype and toxicity of the recently discovered exlA-positive Pseudomonas aeruginosa strains collected worldwide. Environ Microbiol 2016; 18:3425-3439. [PMID: 26914644 DOI: 10.1111/1462-2920.13262] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 02/11/2016] [Indexed: 11/30/2022]
Abstract
We recently identified a hypervirulent strain of Pseudomonas aeruginosa, differing significantly from the classical strains in that it lacks the type 3 secretion system (T3SS), a major determinant of P. aeruginosa virulence. This new strain secretes a novel toxin, called ExlA, which induces plasma membrane rupture in host cells. For this study, we collected 18 other exlA-positive T3SS-negative strains, analyzed their main virulence factors and tested their toxicity in various models. Phylogenetic analysis revealed two groups. The strains were isolated on five continents from patients with various pathologies or in the environment. Their proteolytic activity and their motion abilities were highly different, as well as their capacity to infect epithelial, endothelial, fibroblastic and immune cells, which correlated directly with ExlA secretion levels. In contrast, their toxicity towards human erythrocytes was limited. Some strains were hypervirulent in a mouse pneumonia model and others on chicory leaves. We conclude that (i) exlA-positive strains can colonize different habitats and may induce various infection types, (ii) the strains secreting significant amounts of ExlA are cytotoxic for most cell types but are poorly hemolytic, (iii) toxicity in planta does not correlate with ExlA secretion.
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Affiliation(s)
- Emeline Reboud
- Univ. Grenoble Alpes, 38000, Grenoble, France
- CNRS, ERL5261, 38000, Grenoble, France
- CEA, iRTSV-BCI, 38000, Grenoble, France
- INSERM, U1036, 38000, Grenoble, France
| | - Sylvie Elsen
- Univ. Grenoble Alpes, 38000, Grenoble, France
- CNRS, ERL5261, 38000, Grenoble, France
- CEA, iRTSV-BCI, 38000, Grenoble, France
- INSERM, U1036, 38000, Grenoble, France
| | - Stéphanie Bouillot
- Univ. Grenoble Alpes, 38000, Grenoble, France
- CNRS, ERL5261, 38000, Grenoble, France
- CEA, iRTSV-BCI, 38000, Grenoble, France
- INSERM, U1036, 38000, Grenoble, France
| | - Guillaume Golovkine
- Univ. Grenoble Alpes, 38000, Grenoble, France
- CNRS, ERL5261, 38000, Grenoble, France
- CEA, iRTSV-BCI, 38000, Grenoble, France
- INSERM, U1036, 38000, Grenoble, France
| | - Pauline Basso
- Univ. Grenoble Alpes, 38000, Grenoble, France
- CNRS, ERL5261, 38000, Grenoble, France
- CEA, iRTSV-BCI, 38000, Grenoble, France
- INSERM, U1036, 38000, Grenoble, France
| | - Katy Jeannot
- Hôpital Universitaire de Besançon, 25030, Besançon, France
| | - Ina Attrée
- Univ. Grenoble Alpes, 38000, Grenoble, France
- CNRS, ERL5261, 38000, Grenoble, France
- CEA, iRTSV-BCI, 38000, Grenoble, France
- INSERM, U1036, 38000, Grenoble, France
| | - Philippe Huber
- Univ. Grenoble Alpes, 38000, Grenoble, France.
- CNRS, ERL5261, 38000, Grenoble, France.
- CEA, iRTSV-BCI, 38000, Grenoble, France.
- INSERM, U1036, 38000, Grenoble, France.
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Alvarez DF, Housley N, Koloteva A, Zhou C, O'Donnell K, Audia JP. Caspase-1 Activation Protects Lung Endothelial Barrier Function during Infection-Induced Stress. Am J Respir Cell Mol Biol 2016; 55:500-510. [PMID: 27119735 DOI: 10.1165/rcmb.2015-0386oc] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Dysregulated activation of the inflammasome-caspase-1-IL-1β axis elicits damaging hyperinflammation during critical illnesses, such as pneumonia and sepsis. However, in critical illness models of Salmonella infection, burn, or shock, caspase-1 inhibition worsens outcomes. These paradoxical effects suggest that caspase-1 drives novel protective responses. Whether the protective effects of caspase-1 activation involve canonical immune cell and/or nonimmune cell responses is unknown. The objective of this study was to test the hypothesis that, in addition to its recognized proinflammatory function, caspase-1 initiates protective stress responses in nonimmune cells. In vivo, lung epithelial and endothelial barrier function and inflammation were assessed in mice infected with Pseudomonas aeruginosa in the presence or absence of a caspase-1 inhibitor. Lung endothelial barrier function was assessed ex vivo in isolated, perfused rat lungs infected with P. aeruginosa in the presence or absence of a caspase-1 inhibitor. Endothelial barrier function during P. aeruginosa infection was assessed in vitro in cultured rat wild-type pulmonary microvascular endothelial cells (PMVECs) or recombinant PMVECs engineered to decrease caspase-1 expression. We demonstrated in vivo that caspase-1 inhibition in P. aeruginosa-infected mice ameliorated hyperinflammation, but, counterintuitively, increased pulmonary edema. Ex vivo, caspase-1 inhibition increased pulmonary permeability in P. aeruginosa-infected isolated rat lungs. To uncouple caspase-1 from its canonical inflammatory role, we used cultured rat PMVECs in vitro and discovered that genetic knockdown of caspase-1 accelerated P. aeruginosa-induced barrier disruption. In conclusion, caspase-1 is a sentinel stress-response regulator that initiates proinflammatory responses and also initiates novel response(s) to protect PMVEC barrier function during pneumonia.
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Affiliation(s)
- Diego F Alvarez
- 1 Department of Physiology and Cell Biology.,2 Center for Lung Biology, and
| | - Nicole Housley
- 2 Center for Lung Biology, and.,3 Department of Microbiology and Immunology, University of South Alabama, Mobile, Alabama
| | | | | | | | - Jonathon P Audia
- 2 Center for Lung Biology, and.,3 Department of Microbiology and Immunology, University of South Alabama, Mobile, Alabama
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34
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Understanding host-pathogen interaction. Intensive Care Med 2016; 42:2084-2086. [PMID: 27665508 DOI: 10.1007/s00134-016-4544-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 09/07/2016] [Indexed: 12/29/2022]
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Faraji F, Mahzounieh M, Ebrahimi A, Fallah F, Teymournejad O, Lajevardi B. Molecular detection of virulence genes in Pseudomonas aeruginosa isolated from children with Cystic Fibrosis and burn wounds in Iran. Microb Pathog 2016; 99:1-4. [PMID: 27457974 DOI: 10.1016/j.micpath.2016.07.013] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 07/21/2016] [Accepted: 07/21/2016] [Indexed: 11/28/2022]
Abstract
Pseudomonas aeruginosa possesses various virulence factors which contribute to the bacterial invasion and toxicity. Moreover, children suffered from Cystic Fibrosis (CF) and burn wounds are at a high risk of various bacterial infections. The aim of this study was to determine the prevalence of virulent genes in P. aeruginosa isolated from children with CF and burn wounds and comparing their virulence genes to figure out the role of every virulent factor in the infections. P. aeruginosa were isolated from sputum, oropharyngeal swabs, and broncho-alveolar lavage (BAL) specimens from CF and burn wounds between June 2013 and June 2014 in Tehran's hospitals. Bacterial genomic DNAs were extracted and uniplex, duplex and multiplex PCR were performed for detection of toxA, algD and plcN, exoS, lasB, plcH genes, respectively. The prevalence rate of virulence genes in P. aeruginosa isolated from CF was; toxA (63.1%), algD (64.6%), plcH (87.7%), plcN (60%), lasB (95.4%) and exoS (70.8%) and virulence genes in P. aeruginosa from burn patients were: toxA (36.9%), algD (70.1%), plcH (79%), plcN (63.1%), lasB (82%) and exoS (21.1%). The prevalence of three virulent genes in P. aeruginosa was higher in CF comparing to burn wound infections. We found that the number of toxA, lasB and exoS were significantly higher in the bacteria which were isolated from children with CF. This finding shows that these virulence factors play an important role in CF infections by P. aeroginosa.
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Affiliation(s)
- Fatemeh Faraji
- Dept. of Pathobiology, Faculty of Veterinary Medicine, Shahrekord University, Shahrekord, Iran
| | - Mohammadreza Mahzounieh
- Dept. of Pathobiology, Faculty of Veterinary Medicine, Shahrekord University, Shahrekord, Iran.
| | - Azizollah Ebrahimi
- Dept. of Pathobiology, Faculty of Veterinary Medicine, Shahrekord University, Shahrekord, Iran
| | - Fatemeh Fallah
- Pediatric Infections Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Omid Teymournejad
- Department of Microbiology, Babol University of Medical Sciences, Babol, Iran
| | - Behnaz Lajevardi
- Pediatric Infections Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Abstract
INTRODUCTION Hospital-acquired pneumonia (HAP) is one of the leading nosocomial infections worldwide and is associated with an elevated morbidity and mortality and increased hospital costs. Nevertheless, prompt and adequate antimicrobial treatment is mandatory following VAP development, especially in the face of multidrug resistant pathogens. AREAS COVERED We searched Pubmed and ClinicalTrials.gov site reports in English language of phase III clinical trials, between 2000-2016 referring to the antibiotic treatment of nosocomial pneumonia. We provide a summary of latest approved drugs for HAP and emerging drugs with potential indication nosocomial pneumonia. EXPERT OPINION There are several promising compounds on their way, as tedizolid-a new oxazolidone, iclaprim-a novel drug, related to trimethoprim, plazomicin-a new aminoglycoside and two combinations of ceftazidime/avibactam and ceftolozane/tazobactam against MDR bacteria, especially against MRSA and Gram-negative ESBL bacteria.
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Affiliation(s)
- Adamantia Liapikou
- a 6th Respiratory Department , Sotiria Chest Diseases Hospital , Athens , Greece
| | - Antoni Torres
- b Department of Pneumology, Institut Clinic del Tórax, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigaciones biomedicas En Red-Enfermedades Respiratorias (CibeRes CB06/06/0028)-ISCIII, Hospital Clinic , University of Barcelona , Barcelona , Spain
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van der Plas MJA, Bhongir RKV, Kjellström S, Siller H, Kasetty G, Mörgelin M, Schmidtchen A. Pseudomonas aeruginosa elastase cleaves a C-terminal peptide from human thrombin that inhibits host inflammatory responses. Nat Commun 2016; 7:11567. [PMID: 27181065 PMCID: PMC4873665 DOI: 10.1038/ncomms11567] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 04/08/2016] [Indexed: 12/20/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen known for its immune evasive abilities amongst others by degradation of a large variety of host proteins. Here we show that digestion of thrombin by P. aeruginosa elastase leads to the release of the C-terminal thrombin-derived peptide FYT21, which inhibits pro-inflammatory responses to several pathogen-associated molecular patterns in vitro and in vivo by preventing toll-like receptor dimerization and subsequent activation of down-stream signalling pathways. Thus, P. aeruginosa 'hijacks' an endogenous anti-inflammatory peptide-based mechanism, thereby enabling modulation and circumvention of host responses.
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Affiliation(s)
- Mariena J A van der Plas
- Division of Dermatology and Venereology, Department of Clinical Sciences Lund, Lund University, BMC, Tornavägen 10, Lund SE-22184, Sweden
| | - Ravi K V Bhongir
- Division of Dermatology and Venereology, Department of Clinical Sciences Lund, Lund University, BMC, Tornavägen 10, Lund SE-22184, Sweden
| | - Sven Kjellström
- Department of Biochemistry and Structural Biology, Center for Molecular Protein Science, Lund University, PO Box 124, Lund SE-22362, Sweden
| | - Helena Siller
- Division of Dermatology and Venereology, Department of Clinical Sciences Lund, Lund University, BMC, Tornavägen 10, Lund SE-22184, Sweden
| | - Gopinath Kasetty
- Division of Dermatology and Venereology, Department of Clinical Sciences Lund, Lund University, BMC, Tornavägen 10, Lund SE-22184, Sweden
| | - Matthias Mörgelin
- Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University, BMC, Tornavägen 10, Lund SE-22184, Sweden
| | - Artur Schmidtchen
- Division of Dermatology and Venereology, Department of Clinical Sciences Lund, Lund University, BMC, Tornavägen 10, Lund SE-22184, Sweden.,Dermatology and Venereology, Skane University Hospital, Lasarettsgatan 15, Lund SE-22185, Sweden.,Dermatology, LKCMedicine, Nanyang Technological University, 59 Nanyang Drive, Singapore 636921, Singapore
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Pseudomonas aeruginosa Transmigrates at Epithelial Cell-Cell Junctions, Exploiting Sites of Cell Division and Senescent Cell Extrusion. PLoS Pathog 2016; 12:e1005377. [PMID: 26727615 PMCID: PMC4699652 DOI: 10.1371/journal.ppat.1005377] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 12/09/2015] [Indexed: 12/19/2022] Open
Abstract
To achieve systemic infection, bacterial pathogens must overcome the critical and challenging step of transmigration across epithelial barriers. This is particularly true for opportunistic pathogens such as Pseudomonas aeruginosa, an agent which causes nosocomial infections. Despite extensive study, details on the mechanisms used by this bacterium to transmigrate across epithelial tissues, as well as the entry sites it uses, remain speculative. Here, using real-time microscopy and a model epithelial barrier, we show that P. aeruginosa employs a paracellular transmigration route, taking advantage of altered cell-cell junctions at sites of cell division or when senescent cells are expelled from the cell layer. Once a bacterium transmigrates, it is followed by a cohort of bacteria using the same entry point. The basal compartment is then invaded radially from the initial penetration site. Effective transmigration and propagation require type 4 pili, the type 3 secretion system (T3SS) and a flagellum, although flagellum-deficient bacteria can occasionally invade the basal compartment from wounded areas. In the basal compartment, the bacteria inject the T3SS toxins into host cells, disrupting the cytoskeleton and focal contacts to allow their progression under the cells. Thus, P. aeruginosa exploits intrinsic host cell processes to breach the epithelium and invade the subcellular compartment. In normal situations, the mucosae constitute efficient barriers against the invasion of opportunistic pathogens. The bacteria inducing nosocomial infections take advantage of pre-existing pathological situations to cross the epithelium and spread in deeper tissues. The conditions on the host side permitting transmigration and the combination of virulence factors used by the bacteria to transmigrate are mostly speculative. Here, we studied the transmigration process of Pseudomonas aeruginosa, a bacterium causing hospital-acquired acute and chronic infections. We found that bacteria exploits weakened cell-cell junctions of the epithelium, such as those generated at sites of cell division or when dying cells are extruded from the cell layer, to breach the cell layer, using specific virulence factors and motility appendages.
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Morrow KA, Ochoa CD, Balczon R, Zhou C, Cauthen L, Alexeyev M, Schmalzer KM, Frank DW, Stevens T. Pseudomonas aeruginosa exoenzymes U and Y induce a transmissible endothelial proteinopathy. Am J Physiol Lung Cell Mol Physiol 2015; 310:L337-53. [PMID: 26637633 DOI: 10.1152/ajplung.00103.2015] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Accepted: 12/02/2015] [Indexed: 11/22/2022] Open
Abstract
We tested the hypothesis that Pseudomonas aeruginosa type 3 secretion system effectors exoenzymes Y and U (ExoY and ExoU) induce release of a high-molecular-weight endothelial tau, causing transmissible cell injury characteristic of an infectious proteinopathy. Both the bacterial delivery of ExoY and ExoU and the conditional expression of an activity-attenuated ExoU induced time-dependent pulmonary microvascular endothelial cell gap formation that was paralleled by the loss of intracellular tau and the concomitant appearance of high-molecular-weight extracellular tau. Transfer of the high-molecular-weight tau in filtered supernatant to naïve endothelial cells resulted in intracellular accumulation of tau clusters, which was accompanied by cell injury, interendothelial gap formation, decreased endothelial network stability in Matrigel, and increased lung permeability. Tau oligomer monoclonal antibodies captured monomeric tau from filtered supernatant but did not retrieve higher-molecular-weight endothelial tau and did not rescue the injurious effects of tau. Enrichment and transfer of high-molecular-weight tau to naïve cells was sufficient to cause injury. Thus we provide the first evidence for a pathophysiological stimulus that induces release and transmissibility of high-molecular-weight endothelial tau characteristic of an endothelial proteinopathy.
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Affiliation(s)
- K Adam Morrow
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - Cristhiaan D Ochoa
- Physician-Scientist Training Program, Department of Medicine, University of Texas-Southwestern Medical Center, Dallas, Texas; Division of Pulmonary and Critical Care, University of Texas-Southwestern Medical Center, Dallas, Texas
| | - Ron Balczon
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - Chun Zhou
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - Laura Cauthen
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - Mikhail Alexeyev
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - Katherine M Schmalzer
- Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin; Division of Hematology/Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Dara W Frank
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin; and Center for Infectious Disease Research, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Troy Stevens
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama; Department of Medicine, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama;
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Tayabali AF, Coleman G, Nguyen KC. Virulence Attributes and Host Response Assays for Determining Pathogenic Potential of Pseudomonas Strains Used in Biotechnology. PLoS One 2015; 10:e0143604. [PMID: 26619347 PMCID: PMC4664251 DOI: 10.1371/journal.pone.0143604] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 11/06/2015] [Indexed: 12/31/2022] Open
Abstract
Pseudomonas species are opportunistically pathogenic to humans, yet closely related species are used in biotechnology applications. In order to screen for the pathogenic potential of strains considered for biotechnology applications, several Pseudomonas strains (P.aeruginosa (Pa), P.fluorescens (Pf), P.putida (Pp), P.stutzeri (Ps)) were compared using functional virulence and toxicity assays. Most Pa strains and Ps grew at temperatures between 28°C and 42°C. However, Pf and Pp strains were the most antibiotic resistant, with ciprofloxacin and colistin being the most effective of those tested. No strain was haemolytic on sheep blood agar. Almost all Pa, but not other test strains, produced a pyocyanin-like chromophore, and caused cytotoxicity towards cultured human HT29 cells. Murine endotracheal exposures indicated that the laboratory reference strain, PAO1, was most persistent in the lungs. Only Pa strains induced pro-inflammatory and inflammatory responses, as measured by elevated cytokines and pulmonary Gr-1 -positive cells. Serum amyloid A was elevated at ≥ 48 h post-exposure by only some Pa strains. No relationship was observed between strains and levels of peripheral leukocytes. The species designation or isolation source may not accurately reflect pathogenic potential, since the clinical strain Pa10752 was relatively nonvirulent, but the industrial strain Pa31480 showed comparable virulence to PAO1. Functional assays involving microbial growth, cytotoxicity and murine immunological responses may be most useful for identifying problematic Pseudomonas strains being considered for biotechnology applications.
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Affiliation(s)
- Azam F. Tayabali
- Biotechnology Laboratory, Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Environmental Health Centre, Health Canada, Ottawa, Ontario, Canada
| | - Gordon Coleman
- Biotechnology Laboratory, Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Environmental Health Centre, Health Canada, Ottawa, Ontario, Canada
| | - Kathy C. Nguyen
- Biotechnology Laboratory, Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Environmental Health Centre, Health Canada, Ottawa, Ontario, Canada
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Pharmacological activation of Rap1 antagonizes the endothelial barrier disruption induced by exotoxins ExoS and ExoT of Pseudomonas aeruginosa. Infect Immun 2015; 83:1820-9. [PMID: 25690098 DOI: 10.1128/iai.00010-15] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 02/10/2015] [Indexed: 11/20/2022] Open
Abstract
Most clinical strains of Pseudomonas aeruginosa, a leading agent of nosocomial infections, are multiresistant to antibiotherapy. Because of the paucity of new available antibiotics, the investigation of strategies aimed at limiting the action of its major virulence factors has gained much interest. The type 3 secretion system of P. aeruginosa and its effectors are known to be major determinants of toxicity and are required for bacterial dissemination in the host. Bacterial transmigration across the vascular wall is considered to be an important step in the infectious process. Using human endothelial primary cells, we demonstrate that forskolin (FSK), a drug inducing cyclic AMP (cAMP) elevation in eukaryotic cells, strikingly reduced the cell retraction provoked by two type 3 toxins, ExoS and ExoT, found in the majority of clinical strains. Conversely, cytotoxicity of a strain carrying the type 3 effector ExoU was unaffected by FSK. In addition, FSK altered the capacity of two ExoS/ExoT strains to transmigrate across cell monolayers. In agreement with these findings, other drugs and a cytokine inducing the increase of cAMP intracellular levels have also protected cells from retraction. cAMP is an activator of both protein kinase A and EPAC, a GTPase exchange factor of Rap1. Using activators or inhibitors of either pathway, we show that the beneficial effect of FSK is exerted by the activation of the EPAC/Rap1 axis, suggesting that its protective effect is mediated by reinforcing cell-cell and cell-substrate adhesion.
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A type III secretion negative clinical strain of Pseudomonas aeruginosa employs a two-partner secreted exolysin to induce hemorrhagic pneumonia. Cell Host Microbe 2014; 15:164-76. [PMID: 24528863 DOI: 10.1016/j.chom.2014.01.003] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 12/05/2013] [Accepted: 01/02/2014] [Indexed: 11/21/2022]
Abstract
Virulence of Pseudomonas aeruginosa is typically attributed to its type III secretion system (T3SS). A taxonomic outlier, the P. aeruginosa PA7 strain, lacks a T3SS locus, and no virulence phenotype is attributed to PA7. We characterized a PA7-related, T3SS-negative P. aeruginosa strain, CLJ1, isolated from a patient with fatal hemorrhagic pneumonia. CLJ1 is highly virulent in mice, leading to lung hemorrhage and septicemia. CLJ1-infected primary endothelial cells display characteristics of membrane damage and permeabilization. Proteomic analysis of CLJ1 culture supernatants identified a hemolysin/hemagglutinin family pore-forming toxin, Exolysin (ExlA), that is exported via ExlB, representing a putative two-partner secretion system. A recombinant P. aeruginosa PAO1ΔpscD::exlBA strain, deficient for T3SS but engineered to express ExlA, gained lytic capacity on endothelial cells and full virulence in mice, demonstrating that ExlA is necessary and sufficient for pathogenicity. This highlights clinically relevant T3SS-independent hypervirulence, isolates, and points to a broader P. aeruginosa pathogenic repertoire.
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Rello J, Lisboa T, Koulenti D. Respiratory infections in patients undergoing mechanical ventilation. THE LANCET RESPIRATORY MEDICINE 2014; 2:764-74. [PMID: 25151022 DOI: 10.1016/s2213-2600(14)70171-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Lower respiratory tract infections in mechanically ventilated patients are a frequent cause of antibiotic treatment in intensive-care units. These infections present as severe sepsis or septic shock with respiratory dysfunction in intubated patients. Purulent respiratory secretions are needed for diagnosis, but distinguishing between pneumonia and tracheobronchitis is not easy. Both presentations are associated with longlasting mechanical ventilation and extended intensive-care unit stay, providing a rationale for antibiotic treatment initiation. Differentiation of colonisers from true pathogens is difficult, and microbiological data show Staphylococcus aureus and Pseudomonas aeruginosa to be of great concern because of clinical outcomes and therapeutic challenges. Key management issues include identification of the pathogen, choice of initial empirical antibiotic, and decisions with regard to the resolution pattern.
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Affiliation(s)
- Jordi Rello
- Critical Care Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain; Centro de Investigación Biomédica en Red Enfermedades Respiratorias, Barcelona, Spain; Universitat Autonoma de Barcelona, Barcelona, Spain.
| | - Thiago Lisboa
- Critical Care Department and Infection Control Committee, Programa de Pós-Graduação Pneumologia, Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Rede Institucional de Pesquisa e Inovação em Medicina Intensiva, Complexo Hospitalar Santa Casa, Porto Alegre, Brazil
| | - Despoina Koulenti
- 2nd Critical Care Department, Attikon University Hospital, Athens, Greece; Burns Trauma and Critical Care Research Centre, The University of Queensland, Brisbane, QLD, Australia
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Assessment of panobacumab as adjunctive immunotherapy for the treatment of nosocomial Pseudomonas aeruginosa pneumonia. Eur J Clin Microbiol Infect Dis 2014; 33:1861-7. [PMID: 24859907 DOI: 10.1007/s10096-014-2156-1] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Accepted: 05/05/2014] [Indexed: 12/19/2022]
Abstract
The fully human anti-lipopolysaccharide (LPS) immunoglobulin M (IgM) monoclonal antibody panobacumab was developed as an adjunctive immunotherapy for the treatment of O11 serotype Pseudomonas aeruginosa infections. We evaluated the potential clinical efficacy of panobacumab in the treatment of nosocomial pneumonia. We performed a post-hoc analysis of a multicenter phase IIa trial (NCT00851435) designed to prospectively evaluate the safety and pharmacokinetics of panobacumab. Patients treated with panobacumab (n = 17), including 13 patients receiving the full treatment (three doses of 1.2 mg/kg), were compared to 14 patients who did not receive the antibody. Overall, the 17 patients receiving panobacumab were more ill. They were an average of 72 years old [interquartile range (IQR): 64-79] versus an average of 50 years old (IQR: 30-73) (p = 0.024) and had Acute Physiology and Chronic Health Evaluation II (APACHE II) scores of 17 (IQR: 16-22) versus 15 (IQR: 10-19) (p = 0.043). Adjunctive immunotherapy resulted in an improved clinical outcome in the group receiving the full three-course panobacumab treatment, with a resolution rate of 85 % (11/13) versus 64 % (9/14) (p = 0.048). The Kaplan-Meier survival curve showed a statistically significantly shorter time to clinical resolution in this group of patients (8.0 [IQR: 7.0-11.5] versus 18.5 [IQR: 8-30] days in those who did not receive the antibody; p = 0.004). Panobacumab adjunctive immunotherapy may improve clinical outcome in a shorter time if patients receive the full treatment (three doses). These preliminary results suggest that passive immunotherapy targeting LPS may be a complementary strategy for the treatment of nosocomial O11 P. aeruginosa pneumonia.
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Alexandre Y, Le Berre R, Barbier G, Le Blay G. Screening of Lactobacillus spp. for the prevention of Pseudomonas aeruginosa pulmonary infections. BMC Microbiol 2014; 14:107. [PMID: 24766663 PMCID: PMC4040502 DOI: 10.1186/1471-2180-14-107] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Accepted: 04/22/2014] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND Pseudomonas aeruginosa is an opportunistic pathogen that significantly increases morbidity and mortality in nosocomial infections and cystic fibrosis patients. Its pathogenicity especially relies on the production of virulence factors or resistances to many antibiotics. Since multiplication of antibiotic resistance can lead to therapeutic impasses, it becomes necessary to develop new tools for fighting P. aeruginosa infections. The use of probiotics is one of the ways currently being explored. Probiotics are microorganisms that exert a positive effect on the host's health and some of them are known to possess antibacterial activities. Since most of their effects have been shown in the digestive tract, experimental data compatible with the respiratory environment are strongly needed. The main goal of this study was then to test the capacity of lactobacilli to inhibit major virulence factors (elastolytic activity and biofilm formation) associated with P. aeruginosa pathogenicity. RESULTS Sixty-seven lactobacilli were isolated from the oral cavities of healthy volunteers. These isolates together with 20 lactobacilli isolated from raw milks, were tested for their capacity to decrease biofilm formation and activity of the elastase produced by P. aeruginosa PAO1. Ten isolates, particularly efficient, were accurately identified using a polyphasic approach (API 50 CHL, mass-spectrometry and 16S/rpoA/pheS genes sequencing) and typed by pulsed-field gel electrophoresis (PFGE). The 8 remaining strains belonging to the L. fermentum (6), L. zeae (1) and L. paracasei (1) species were sensitive to all antibiotics tested with the exception of the intrinsic resistance to vancomycin. The strains were all able to grow in artificial saliva. CONCLUSION Eight strains belonging to L. fermentum, L. zeae and L. paracasei species harbouring anti-elastase and anti-biofilm properties are potential probiotics for fighting P. aeruginosa pulmonary infections. However, further studies are needed in order to test their innocuity and their capacity to behave such as an oropharyngeal barrier against Pseudomonas aeruginosa colonisation in vivo.
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MESH Headings
- Adult
- Aged
- Aged, 80 and over
- Animals
- Antibiosis
- Bacterial Proteins/genetics
- DNA, Bacterial/chemistry
- DNA, Bacterial/genetics
- DNA, Ribosomal/chemistry
- DNA, Ribosomal/genetics
- Electrophoresis, Gel, Pulsed-Field
- Female
- Healthy Volunteers
- Humans
- Lactobacillus/classification
- Lactobacillus/genetics
- Lactobacillus/isolation & purification
- Lactobacillus/physiology
- Male
- Mass Spectrometry
- Middle Aged
- Milk/microbiology
- Molecular Sequence Data
- Mouth/microbiology
- Pseudomonas aeruginosa/growth & development
- RNA, Ribosomal, 16S/genetics
- Sequence Analysis, DNA
- Young Adult
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Affiliation(s)
- Youenn Alexandre
- Université de Brest, EA 3882-Laboratoire Universitaire de Biodiversité et d’Écologie Microbienne (LUBEM), Faculté de Médecine, 22 avenue Camille Desmoulins, 29200 Brest, France
| | - Rozenn Le Berre
- Université de Brest, EA 3882-Laboratoire Universitaire de Biodiversité et d’Écologie Microbienne (LUBEM), Faculté de Médecine, 22 avenue Camille Desmoulins, 29200 Brest, France
- Département de Médecine Interne et Pneumologie, CHRU La Cavale-Blanche, 29200 Brest, France
| | - Georges Barbier
- Université de Brest, EA 3882-Laboratoire Universitaire de Biodiversité et d’Écologie Microbienne (LUBEM), Parvis Blaise Pascal, Technopôle Brest-Iroise, 29280 Plouzané, France
| | - Gwenaelle Le Blay
- Université de Brest, EA 3882-Laboratoire Universitaire de Biodiversité et d’Écologie Microbienne (LUBEM), Parvis Blaise Pascal, Technopôle Brest-Iroise, 29280 Plouzané, France
- Université de Brest, CNRS, IFREMER, UMR 6197-Laboratoire de Microbiologie des Environnement Extrêmes (LMEE), Institut Universitaire Européen de la Mer, Place Nicolas Copernic, Technopôle Brest-Iroise, 29280 Plouzané, France
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Stevens TC, Ochoa CD, Morrow KA, Robson MJ, Prasain N, Zhou C, Alvarez DF, Frank DW, Balczon R, Stevens T. The Pseudomonas aeruginosa exoenzyme Y impairs endothelial cell proliferation and vascular repair following lung injury. Am J Physiol Lung Cell Mol Physiol 2014; 306:L915-24. [PMID: 24705722 DOI: 10.1152/ajplung.00135.2013] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Exoenzyme Y (ExoY) is a Pseudomonas aeruginosa toxin that is introduced into host cells through the type 3 secretion system (T3SS). Once inside the host cell cytoplasm, ExoY generates cyclic nucleotides that cause tau phosphorylation and microtubule breakdown. Microtubule breakdown causes interendothelial cell gap formation and tissue edema. Although ExoY transiently induces interendothelial cell gap formation, it remains unclear whether ExoY prevents repair of the endothelial cell barrier. Here, we test the hypothesis that ExoY intoxication impairs recovery of the endothelial cell barrier following gap formation, decreasing migration, proliferation, and lung repair. Pulmonary microvascular endothelial cells (PMVECs) were infected with P. aeruginosa strains for 6 h, including one possessing an active ExoY (PA103 exoUexoT::Tc pUCPexoY; ExoY(+)), one with an inactive ExoY (PA103ΔexoUexoT::Tc pUCPexoY(K81M); ExoY(K81M)), and one that lacks PcrV required for a functional T3SS (ΔPcrV). ExoY(+) induced interendothelial cell gaps, whereas ExoY(K81M) and ΔPcrV did not promote gap formation. Following gap formation, bacteria were removed and endothelial cell repair was examined. PMVECs were unable to repair gaps even 3-5 days after infection. Serum-stimulated growth was greatly diminished following ExoY intoxication. Intratracheal inoculation of ExoY(+) and ExoY(K81M) caused severe pneumonia and acute lung injury. However, whereas the pulmonary endothelial cell barrier was functionally improved 1 wk following ExoY(K81M) infection, pulmonary endothelium was unable to restrict the hyperpermeability response to elevated hydrostatic pressure following ExoY(+) infection. In conclusion, ExoY is an edema factor that chronically impairs endothelial cell barrier integrity following lung injury.
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Affiliation(s)
- Trevor C Stevens
- Center for Lung Biology, University of South Alabama, Mobile, Alabama;
| | - Cristhiaan D Ochoa
- Physician-Scientist Training Program, Department of Medicine, University of Texas-Southwestern Medical Center, Dallas, Texas; Division of Pulmonary and Critical Care, University of Texas-Southwestern Medical Center, Dallas, Texas
| | - K Adam Morrow
- Department of Pharmacology, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - Matthew J Robson
- Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - Nutan Prasain
- Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University, Indianapolis, Indiana
| | - Chun Zhou
- Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - Diego F Alvarez
- Department of Pharmacology, University of South Alabama, Mobile, Alabama; Department of Medicine, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - Dara W Frank
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin; and Center for Infectious Disease Research, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Ron Balczon
- Department of Cell Biology and Neuroscience, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - Troy Stevens
- Department of Pharmacology, University of South Alabama, Mobile, Alabama; Department of Medicine, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
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Koch H, Emrich T, Jampen S, Wyss M, Gafner V, Lazar H, Rudolf MP. Development of a 4-valent genotyping assay for direct identification of the most frequent Pseudomonas aeruginosa serotypes from respiratory specimens of pneumonia patients. J Med Microbiol 2014; 63:508-517. [PMID: 24430251 DOI: 10.1099/jmm.0.066043-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Pseudomonas aeruginosa is a common cause of nosocomial infections and is associated with high rates of mortality. In order to facilitate rapid and sensitive identification of the most prevalent serotypes of P. aeruginosa, we have developed a 4-valent real-time PCR-based assay using oligonucleotides specific for open-reading frames constituting the O-antigen-specific lipopolysaccharide loci of P. aeruginosa. The assay simultaneously detects and differentiates between each of the four serotypes IATS-O1, -O6, -O11 and serogroup 2 (IATS-O2, -O5, and -O16) with high sensitivity and specificity in a single-tube reaction. No cross-reactivity was observed with other serotypes of P. aeruginosa or other microbial species, and reproducibility was demonstrated regardless of template, i.e. purified DNA, bacterial culture and clinical specimens (broncho-alveolar lavage). The limit of detection of the assay was approximately 100 copies per reaction for IATS-O1, -O2 and -O11, and 50 copies per reaction for IATS-O6. Comparison of the assay specificity with a commercially available slide agglutination kit showed consistent results; however, the number of non-typable isolates was reduced by 15 % using the genotyping assay. Use of the 4-valent genotyping assay in the context of a clinical trial resulted in identification of pneumonia patients positive for the IATS-O11 serotype, and hence eligible for therapy with panobacumab (an investigational monoclonal antibody against the O-polysaccharide of serotype IATS-O11).
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Affiliation(s)
- Holger Koch
- Kenta Biotech AG, Wagistrasse 25, CH-8952 Schlieren, Switzerland
| | - Thomas Emrich
- Kenta Biotech AG, Wagistrasse 25, CH-8952 Schlieren, Switzerland
| | - Sandra Jampen
- Kenta Biotech AG, Wagistrasse 25, CH-8952 Schlieren, Switzerland
| | - Marianne Wyss
- Kenta Biotech AG, Wagistrasse 25, CH-8952 Schlieren, Switzerland
| | - Verena Gafner
- Kenta Biotech AG, Wagistrasse 25, CH-8952 Schlieren, Switzerland
| | - Hedvika Lazar
- Kenta Biotech AG, Wagistrasse 25, CH-8952 Schlieren, Switzerland
| | - Michael P Rudolf
- Kenta Biotech AG, Wagistrasse 25, CH-8952 Schlieren, Switzerland
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Lovewell RR, Patankar YR, Berwin B. Mechanisms of phagocytosis and host clearance of Pseudomonas aeruginosa. Am J Physiol Lung Cell Mol Physiol 2014; 306:L591-603. [PMID: 24464809 DOI: 10.1152/ajplung.00335.2013] [Citation(s) in RCA: 123] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Pseudomonas aeruginosa is an opportunistic bacterial pathogen responsible for a high incidence of acute and chronic pulmonary infection. These infections are particularly prevalent in patients with chronic obstructive pulmonary disease and cystic fibrosis: much of the morbidity and pathophysiology associated with these diseases is due to a hypersusceptibility to bacterial infection. Innate immunity, primarily through inflammatory cytokine production, cellular recruitment, and phagocytic clearance by neutrophils and macrophages, is the key to endogenous control of P. aeruginosa infection. In this review, we highlight recent advances toward understanding the innate immune response to P. aeruginosa, with a focus on the role of phagocytes in control of P. aeruginosa infection. Specifically, we summarize the cellular and molecular mechanisms of phagocytic recognition and uptake of P. aeruginosa, and how current animal models of P. aeruginosa infection reflect clinical observations in the context of phagocytic clearance of the bacteria. Several notable phenotypic changes to the bacteria are consistently observed during chronic pulmonary infections, including changes to mucoidy and flagellar motility, that likely enable or reflect their ability to persist. These traits are likewise examined in the context of how the bacteria avoid phagocytic clearance, inflammation, and sterilizing immunity.
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Affiliation(s)
- Rustin R Lovewell
- Dept. of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, 1 Medical Center Dr., Lebanon, NH 03756.
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Lu Q, Eggimann P, Luyt CE, Wolff M, Tamm M, François B, Mercier E, Garbino J, Laterre PF, Koch H, Gafner V, Rudolf MP, Mus E, Perez A, Lazar H, Chastre J, Rouby JJ. Pseudomonas aeruginosa serotypes in nosocomial pneumonia: prevalence and clinical outcomes. Crit Care 2014; 18:R17. [PMID: 24428878 PMCID: PMC4057348 DOI: 10.1186/cc13697] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Accepted: 01/08/2014] [Indexed: 11/10/2022] Open
Abstract
INTRODUCTION Pseudomonas aeruginosa frequently causes nosocomial pneumonia and is associated with poor outcome. The purpose of this study was to assess the prevalence and clinical outcome of nosocomial pneumonia caused by serotype-specific P. aeruginosa in critically ill patients under appropriate antimicrobial therapy management. METHODS A retrospective, non-interventional epidemiological multicenter cohort study involving 143 patients with confirmed nosocomial pneumonia caused by P. aeruginosa. Patients were analyzed for a period of 30 days from time of nosocomial pneumonia onset. Fourteen patients fulfilling the same criteria from a phase IIa studyconducted at the same time/centers were included in the prevalence calculations but not in the clinical outcome analysis. RESULTS The prevalence of serotypes was: O6 (29%), O11 (23%), O10 (10%), O2 (9%), and O1 (8%). Serotypes with a prevalence of less than 5% were found in 13% of patients, 8% were classified as not typeable. Across all serotypes, 19% mortality, 70% clinical resolution, 11% clinical continuation, and 5% clinical recurrence were recorded. Age and higher APACHE II (Acute Physiology and Chronic Health Evaluation II) were predictive risk factors associated with probability of death and lower clinical resolution for P. aeruginosa nosocomial pneumonia. Mortality tends to be higher with O1 (40%) and lower with O2 (0%); clinical resolution tends to be better with O2 (82%) compared to other serotypes. Persisting pneumonia with O6 and O11 was, respectively, 8% and 21%; clinical resolution with O6 and O11 was, respectively, 75% and 57%. CONCLUSIONS In P. aeruginosa nosocomial pneumonia, the most prevalent serotypes were O6 and O11. Further studies including larger group sizes are needed to correlate clinical outcome with virulence factors of P. aeruginosa in patients with nosocomial pneumonia caused by various serotypes; and to compare O6 and O11, the two serotypes most frequently encountered in critically ill patients.
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50
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Audia JP, Lindsey AS, Housley NA, Ochoa CR, Zhou C, Toba M, Oka M, Annamdevula NS, Fitzgerald MS, Frank DW, Alvarez DF. In the absence of effector proteins, the Pseudomonas aeruginosa type three secretion system needle tip complex contributes to lung injury and systemic inflammatory responses. PLoS One 2013; 8:e81792. [PMID: 24312357 PMCID: PMC3842252 DOI: 10.1371/journal.pone.0081792] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Accepted: 10/16/2013] [Indexed: 01/06/2023] Open
Abstract
Herein we describe a pathogenic role for the Pseudomonas aeruginosa type three secretion system (T3SS) needle tip complex protein, PcrV, in causing lung endothelial injury. We first established a model in which P. aeruginosa wild type strain PA103 caused pneumonia-induced sepsis and distal organ dysfunction. Interestingly, a PA103 derivative strain lacking its two known secreted effectors, ExoU and ExoT [denoted PA103 (ΔU/ΔT)], also caused sepsis and modest distal organ injury whereas an isogenic PA103 strain lacking the T3SS needle tip complex assembly protein [denoted PA103 (ΔPcrV)] did not. PA103 (ΔU/ΔT) infection caused neutrophil influx into the lung parenchyma, lung endothelial injury, and distal organ injury (reminiscent of sepsis). In contrast, PA103 (ΔPcrV) infection caused nominal neutrophil infiltration and lung endothelial injury, but no distal organ injury. We further examined pathogenic mechanisms of the T3SS needle tip complex using cultured rat pulmonary microvascular endothelial cells (PMVECs) and revealed a two-phase, temporal nature of infection. At 5-hours post-inoculation (early phase infection), PA103 (ΔU/ΔT) elicited PMVEC barrier disruption via perturbation of the actin cytoskeleton and did so in a cell death-independent manner. Conversely, PA103 (ΔPcrV) infection did not elicit early phase PMVEC barrier disruption. At 24-hours post-inoculation (late phase infection), PA103 (ΔU/ΔT) induced PMVEC damage and death that displayed an apoptotic component. Although PA103 (ΔPcrV) infection induced late phase PMVEC damage and death, it did so to an attenuated extent. The PA103 (ΔU/ΔT) and PA103 (ΔPcrV) mutants grew at similar rates and were able to adhere equally to PMVECs post-inoculation indicating that the observed differences in damage and barrier disruption are likely attributable to T3SS needle tip complex-mediated pathogenic differences post host cell attachment. Together, these infection data suggest that the T3SS needle tip complex and/or another undefined secreted effector(s) are important determinants of P. aeruginosa pneumonia-induced lung endothelial barrier disruption.
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Affiliation(s)
- Jonathon P. Audia
- Department of Microbiology and Immunology, University of South Alabama, Mobile, Alabama, United States of America
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States of America
- * E-mail: (JPA); (DFA)
| | - Ashley S. Lindsey
- Department of Pharmacology, University of South Alabama, Mobile, Alabama, United States of America
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States of America
| | - Nicole A. Housley
- Department of Microbiology and Immunology, University of South Alabama, Mobile, Alabama, United States of America
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States of America
| | - Courtney R. Ochoa
- Department of Pharmacology, University of South Alabama, Mobile, Alabama, United States of America
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States of America
| | - Chun Zhou
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States of America
| | - Michie Toba
- Department of Pharmacology, University of South Alabama, Mobile, Alabama, United States of America
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States of America
| | - Masahiko Oka
- Department of Pharmacology, University of South Alabama, Mobile, Alabama, United States of America
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States of America
| | - Naga S. Annamdevula
- Department of Chemical and Biomolecular Engineering, University of South Alabama, Mobile, Alabama, United States of America
| | - Meshann S. Fitzgerald
- Department of Internal Medicine, University of South Alabama, Mobile, Alabama, United States of America
- Department of Pharmacology, University of South Alabama, Mobile, Alabama, United States of America
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States of America
| | - Dara W. Frank
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Diego F. Alvarez
- Department of Internal Medicine, University of South Alabama, Mobile, Alabama, United States of America
- Department of Pharmacology, University of South Alabama, Mobile, Alabama, United States of America
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States of America
- * E-mail: (JPA); (DFA)
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