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Zhan Y, Hu H, Yu Y, Chen C, Zhang J, Jarnda KV, Ding P. Therapeutic strategies for drug-resistant Pseudomonas aeruginosa: Metal and metal oxide nanoparticles. J Biomed Mater Res A 2024; 112:1343-1363. [PMID: 38291785 DOI: 10.1002/jbm.a.37677] [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: 09/11/2023] [Revised: 12/25/2023] [Accepted: 01/16/2024] [Indexed: 02/01/2024]
Abstract
Pseudomonas aeruginosa (PA) is a widely prevalent opportunistic pathogen. Multiple resistant strains of PA have emerged from excessive or inappropriate use of antibiotics, making their eradication increasingly difficult. Therefore, the search for highly efficient and secure novel antimicrobial agents is crucial. According to reports, there is an increasing exploration of nanometals for antibacterial purposes. The antibacterial mechanisms involving the nanomaterials themselves, the release of ions, and the induced oxidative stress causing leakage and damage to biomolecules are widely accepted. Additionally, the study of the cytotoxicity of metal nanoparticles is crucial for their antibacterial applications. This article summarizes the types of metal nanomaterials and metal oxide nanomaterials that can be used against PA, their respective unique antibacterial mechanisms, cytotoxicity, and efforts made to improve antibacterial performance and reduce toxicity, including combination therapy with other materials and antibiotics, as well as green synthesis approaches.
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Affiliation(s)
- Yujuan Zhan
- Xiang Ya School of Public Health, Central South University, Changsha, Hunan, China
- Hunan Provincial Key Laboratory of Clinical Epidemiology, Changsha, Hunan, China
| | - Huiting Hu
- Xiang Ya School of Public Health, Central South University, Changsha, Hunan, China
- Hunan Provincial Key Laboratory of Clinical Epidemiology, Changsha, Hunan, China
| | - Ying Yu
- Xiang Ya School of Public Health, Central South University, Changsha, Hunan, China
- Hunan Provincial Key Laboratory of Clinical Epidemiology, Changsha, Hunan, China
| | - Cuimei Chen
- School of Public Health, Xiangnan University, Chenzhou, Hunan, China
| | - Jingwen Zhang
- Xiang Ya School of Public Health, Central South University, Changsha, Hunan, China
- Hunan Provincial Key Laboratory of Clinical Epidemiology, Changsha, Hunan, China
| | - Kermue Vasco Jarnda
- Xiang Ya School of Public Health, Central South University, Changsha, Hunan, China
- Hunan Provincial Key Laboratory of Clinical Epidemiology, Changsha, Hunan, China
| | - Ping Ding
- Xiang Ya School of Public Health, Central South University, Changsha, Hunan, China
- Hunan Provincial Key Laboratory of Clinical Epidemiology, Changsha, Hunan, China
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Tribin FE, Lieux C, Maestre-Mesa J, Durkee H, Krishna K, Chou B, Neag E, Tóthová JD, Martinez JD, Flynn HW, Parel JM, Miller D, Amescua G. Clinical Features and Treatment Outcomes of Carbapenem-Resistant Pseudomonas aeruginosa Keratitis. JAMA Ophthalmol 2024; 142:407-415. [PMID: 38512246 PMCID: PMC10958388 DOI: 10.1001/jamaophthalmol.2024.0259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Accepted: 12/27/2023] [Indexed: 03/22/2024]
Abstract
Importance Evaluation of the microbiological diagnostic profile of multidrug-resistant Pseudomonas aeruginosa keratitis and potential management with rose bengal-photodynamic antimicrobial therapy (RB-PDAT) is important. Objective To document the disease progression of carbapenemase-resistant P aeruginosa keratitis after an artificial tear contamination outbreak. Design, Setting, and Participants This retrospective observation case series included 9 patients 40 years or older who presented at Bascom Palmer Eye Institute and had positive test results for multidrug-resistant P aeruginosa keratitis between January 1, 2022, and October 31, 2023. Main Outcomes and Measures Evaluation of type III secretion phenotype, carbapenemase-resistance genes blaGES and blaVIM susceptibility to antibiotics, and in vitro and in vivo outcomes of RB-PDAT against multidrug-resistant P aeruginosa keratitis. Results Among the 9 patients included in the analysis (5 women and 4 men; mean [SD] age, 73.4 [14.0] years), all samples tested positive for exoU and carbapenemase-resistant blaVIM and blaGES genes. Additionally, isolates were resistant to carbapenems as indicated by minimum inhibitory concentration testing. In vitro efficacy of RB-PDAT indicated its potential application for treating recalcitrant cases. These cases highlight the rapid progression and challenging management of multidrug-resistant P aeruginosa. Two patients were treated with RB-PDAT as an adjuvant to antibiotic therapy and had improved visual outcomes. Conclusions and Relevance This case series highlights the concerning progression in resistance and virulence of P aeruginosa and emphasizes the need to explore alternative therapies like RB-PDAT that have broad coverage and no known antibiotic resistance. The findings support further investigation into the potential effects of RB-PDAT for other multidrug-resistant microbes.
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Affiliation(s)
- Felipe Echeverri Tribin
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida
| | - Caroline Lieux
- Anne Bates Leach Eye Center, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida
| | - Jorge Maestre-Mesa
- Ocular Microbiology Laboratory, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida
| | - Heather Durkee
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida
| | - Katherine Krishna
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida
| | - Brandon Chou
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida
| | - Emily Neag
- Anne Bates Leach Eye Center, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida
| | - Jana D’Amato Tóthová
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida
| | - Jaime D. Martinez
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida
| | - Harry W. Flynn
- Anne Bates Leach Eye Center, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida
- Ocular Microbiology Laboratory, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida
| | - Jean Marie Parel
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida
- Anne Bates Leach Eye Center, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida
- Ocular Microbiology Laboratory, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida
| | - Darlene Miller
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida
- Anne Bates Leach Eye Center, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida
- Ocular Microbiology Laboratory, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida
| | - Guillermo Amescua
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida
- Anne Bates Leach Eye Center, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida
- Ocular Microbiology Laboratory, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida
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Gervasoni LF, Peixoto IC, Imperador AC, De Oliveira LB, Correia LF, de Oliveira Vieira KC, Saeki EK, da Silva Lima PE, Mareco EA, Pereira VC, Winkelströter Eller LK. "Relationship between antibiotic resistance, biofilm formation, virulence factors and source of origin of Pseudomonas aeruginosa environmental isolates with regard to the presence of metallo-β-lactamase-encoding genes". Microb Pathog 2023; 182:106223. [PMID: 37423498 DOI: 10.1016/j.micpath.2023.106223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 06/22/2023] [Accepted: 06/30/2023] [Indexed: 07/11/2023]
Abstract
A total of 557 water samples were evaluated and of these, 23 were positive for the presence of Pseudomonas aeruginosa. Approximately 91.7% of them were weak biofilm formers. Only 4 isolates showed antimicrobial resistance. All isolates presented Twitching motility, a positive result for the production of pyocyanin, alkaline protease, and hemolysins. The genotypic tests showed: lasA, (95.6%) lasB (95.6%), exoS (95.6%), exoT (91.3%), toxA (91.3%), akgO (91.3%), plcN (91.3%) aprA (86.9%), phzM (78.3%), and pvdA (60.9%). For genes encoding metallo-beta-lactamase, it was found: blaVIM (56.6%), blaSPM (4.3%), and blaSIM (47.8%). A strong association was found between the metallo-beta-lactamase producing genes, nine genes of virulence factors and the motility (r = 0.6231). The very close clonal profile suggests a probable similarity between the isolates from different cities. Thus, P. aeruginosa can be present in water supplies with variable virulence capacities and can generate a huge concern for human, animal, and environmental health.
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Affiliation(s)
- Letícia Franco Gervasoni
- Faculty of Health Science, University of Western São Paulo - Rua José Bongiovani, 700 - Cidade Universitária, CEP: 19050-920. Presidente Prudente, SP/Brazil
| | - Inaiá Calegari Peixoto
- Faculty of Health Science, University of Western São Paulo - Rua José Bongiovani, 700 - Cidade Universitária, CEP: 19050-920. Presidente Prudente, SP/Brazil
| | - Anna Cardoso Imperador
- Faculty of Health Science, University of Western São Paulo - Rua José Bongiovani, 700 - Cidade Universitária, CEP: 19050-920. Presidente Prudente, SP/Brazil
| | - Lívia Batista De Oliveira
- Faculty of Health Science, University of Western São Paulo - Rua José Bongiovani, 700 - Cidade Universitária, CEP: 19050-920. Presidente Prudente, SP/Brazil
| | - Lucimeire Fernandes Correia
- Health Science, University of Western São Paulo - Rua José Bongiovani, 700 - Cidade Universitária, CEP: 19050-920. Presidente Prudente, SP/Brazil
| | - Karolinny Cristiny de Oliveira Vieira
- Program of Animal Science, University of Western São Paulo, - Rua José Bongiovani, 700 - Cidade Universitária, CEP: 19050-920. Presidente Prudente, SP/Brazil
| | - Erika Kushikawa Saeki
- Regional Laboratory of Presidente Prudente, Adolfo Lutz Institute - Avenida Coronel José Soares Marcondes, 2357 - Vila Maristela, CEP: 19020-120. Presidente Prudente, SP/Brazil
| | - Paula Esteves da Silva Lima
- Regional Laboratory of Presidente Prudente, Adolfo Lutz Institute - Avenida Coronel José Soares Marcondes, 2357 - Vila Maristela, CEP: 19020-120. Presidente Prudente, SP/Brazil
| | - Edson Assunção Mareco
- Environment and Regional Development Graduate Program, University of Western São Paulo - Rua José Bongiovani, 700 - Cidade Universitária, CEP: 19050-920. Presidente Prudente, SP/Brazil
| | - Valéria Cataneli Pereira
- Faculty of Health Science, University of Western São Paulo - Rua José Bongiovani, 700 - Cidade Universitária, CEP: 19050-920. Presidente Prudente, SP/Brazil; Health Science, University of Western São Paulo - Rua José Bongiovani, 700 - Cidade Universitária, CEP: 19050-920. Presidente Prudente, SP/Brazil
| | - Lizziane Kretli Winkelströter Eller
- Faculty of Health Science, University of Western São Paulo - Rua José Bongiovani, 700 - Cidade Universitária, CEP: 19050-920. Presidente Prudente, SP/Brazil; Health Science, University of Western São Paulo - Rua José Bongiovani, 700 - Cidade Universitária, CEP: 19050-920. Presidente Prudente, SP/Brazil; Program of Animal Science, University of Western São Paulo, - Rua José Bongiovani, 700 - Cidade Universitária, CEP: 19050-920. Presidente Prudente, SP/Brazil.
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Shah S, Wozniak RAF. Staphylococcus aureus and P seudomonas aeruginosa infectious keratitis: key bacterial mechanisms that mediate pathogenesis and emerging therapeutics. Front Cell Infect Microbiol 2023; 13:1250257. [PMID: 37671149 PMCID: PMC10475732 DOI: 10.3389/fcimb.2023.1250257] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 08/04/2023] [Indexed: 09/07/2023] Open
Abstract
Bacterial keratitis (bacterial infection of the cornea) is a major cause of vision loss worldwide. Given the rapid and aggressive nature of the disease, immediate broad-spectrum antibiotics are essential to adequately treat this disease. However, rising antibiotic resistance continues to accelerate, rendering many commonly used therapeutics increasingly ineffective. As such, there is a significant effort to understand the basic pathogenesis of common causative organisms implicated in keratitis in part, to fuel the development of novel therapies to treat this blinding disease. This review explores two common causes of bacterial keratitis, Staphylococcus aureus and Pseudomonas aeruginosa, with regards to the bacterial mediators of virulence as well as novel therapies on the horizon.
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Affiliation(s)
| | - Rachel A. F. Wozniak
- Department of Ophthalmology, The University of Rochester School of Medicine and Dentistry, Rochester, NY, United States
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Englisch CN, Wadood NA, Pätzold L, Gallagher A, Krasteva-Christ G, Becker SL, Bischoff M. Establishing an Experimental Pseudomonas aeruginosa Keratitis Model in Mice - Challenges and Solutions. Ann Anat 2023; 249:152099. [PMID: 37105406 DOI: 10.1016/j.aanat.2023.152099] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 03/27/2023] [Accepted: 03/28/2023] [Indexed: 04/29/2023]
Abstract
BACKGROUND With the ongoing increase in antimicrobial resistances seen in bacterial isolates causing a keratitis in humans, animal models have become an important tool to study new antimicrobial therapies. Nevertheless, the establishment of experimental keratitis is difficult. Here, we discuss the impact of different arrangements, including animal age, bacterial strain and dose as well as epithelium removal on the outcome of experimental keratitis. We therefore present the methods and results of our establishing experiments. METHODS Bacterial load determination and flow cytometry were performed using eye homogenate gained from a 72hours lasting murine Pseudomonas aeruginosa keratitis model. Additionally, the intensity of the infection was scored from 0 to 5, the mice weighed, and blood immune cells counted. RESULTS We found that older C57BL/6N mice (8-11 months) are more susceptible to develop a keratitis than younger mice (5-6 weeks). Epithelium removal has no major impact on infectivity and disease progression in aged mice. P. aeruginosa exoU+ strains, such as PA54, should preferentially be used and highly concentrated (∼ 5×107 CFU). Establishing an infection with the exoU- PAO1 derivative DSM 19880 was not possible. CONCLUSIONS We present a replicable method to achieve a successful experimental P. aeruginosa keratitis in C57BL/6N mice that is sustained or aggravated over the observation period of 3 days in 80% of all animals tested. Our work is of particular interest to all researchers planning the establishment of such experimental models. We show some key aspects that can simplify and quicken the procedure, ultimately saving costs and animal life.
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Affiliation(s)
- Colya N Englisch
- Institute for Medical Microbiology and Hygienics, Saarland University, 66421, Homburg/Saar, Germany.
| | - Noran Abdel Wadood
- Institute for Medical Microbiology and Hygienics, Saarland University, 66421, Homburg/Saar, Germany; Institute of Anatomy and Cell Biology, Saarland University, 66421, Homburg/Saar, Germany.
| | - Linda Pätzold
- Institute for Medical Microbiology and Hygienics, Saarland University, 66421, Homburg/Saar, Germany.
| | | | | | - Sören L Becker
- Institute for Medical Microbiology and Hygienics, Saarland University, 66421, Homburg/Saar, Germany.
| | - Markus Bischoff
- Institute for Medical Microbiology and Hygienics, Saarland University, 66421, Homburg/Saar, Germany.
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Fakhkhari P, Tajeddin E, Azimirad M, Salmanzadeh-Ahrabi S, Abdi-Ali A, Nikmanesh B, Eshrati B, Gouya MM, Owlia P, Zali MR, Alebouyeh M. Involvement of Pseudomonas aeruginosa in the occurrence of community and hospital acquired diarrhea, and its virulence diversity among the stool and the environmental samples. INTERNATIONAL JOURNAL OF ENVIRONMENTAL HEALTH RESEARCH 2022; 32:61-71. [PMID: 32073302 DOI: 10.1080/09603123.2020.1726300] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Accepted: 02/03/2020] [Indexed: 06/10/2023]
Abstract
Transmission of Pseudomonas aeruginosa along the food chain could cause gastrointestinal infections. To show this involvement, the prevalence, putative virulence genotype, and antibiotic resistance phenotype of P. aeruginosa isolates from stool of 1482 patients with community and hospital acquired diarrhea were compared with 87 isolates from the environmental samples. The results showed infection with P. aeruginosa in 3.4% of the cases, while 57.4% of vegetable samples were contaminated. Significantly higher frequency of lasB (98%), aprA (98%), exoY (98%), and exoS (90%), but lower rate of exoT (39.2%), was detected among the stool isolates. Multi-drug resistance (MDR) phenotype was detected in 25.5% and 4% of the stool and vegetable isolates, respectively. A higher rate of studied virulence genes was detected among the MDR strains vs non-MDR strains. These results indicate P. aeruginosa as a causative agent of diarrhea either among the hospitalized patients and those with community-acquired diarrhea.
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Affiliation(s)
- Parisa Fakhkhari
- Department of Microbiology, Faculty of Biological Sciences, Alzahra University, Tehran, Iran
| | - Elahe Tajeddin
- Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Masoumeh Azimirad
- Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Ahya Abdi-Ali
- Department of Microbiology, Faculty of Biological Sciences, Alzahra University, Tehran, Iran
| | - Bahram Nikmanesh
- Department of Medical Laboratory Sciences, School of Allied Medical Sciences, Tehran University of Medical Sciences, Tehran, Iran
| | - Babak Eshrati
- Center for Communicable Disease Control, Ministry of Health and Medical Education, Tehran, Iran
| | - Mohammad Mehdi Gouya
- Center for Communicable Disease Control, Ministry of Health and Medical Education, Tehran, Iran
| | - Parviz Owlia
- Molecular Microbiology Research Center (MMRC), Shahed University, Tehran, Iran
| | - Mohammad Reza Zali
- Gastroenterology and Liver Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Masoud Alebouyeh
- Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Pediatric Infections Research Center, Research Institute for Children's Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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7
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Shen E, Yang J, Tsuei KSC. The role of Type III secretion system in the pathogenesis of Pseudomonas aeruginosa microbial keratitis. Tzu Chi Med J 2022; 34:8-14. [PMID: 35233350 PMCID: PMC8830546 DOI: 10.4103/tcmj.tcmj_47_21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 03/11/2021] [Accepted: 03/17/2021] [Indexed: 11/22/2022] Open
Abstract
Pseudomonas aeruginosa is the most commonly isolated Gram-negative pathogen causing sight-threatening microbial keratitis (MK). Contact lens wear is the most significant risk factor associated with pseudomonal MK. Understanding the pathogenesis of MK due to P. aeruginosa and its interactions with contact lenses is crucial in preventing these often rapidly progressive and highly antibiotic-resistant infections. Bacterial virulence factor Type III secretion system (T3SS) has significant interplays between contact lens material, antibiotic sensitivity, disinfectant selectivity, and bacterial cell invasion. Depending on the T3SS exotoxins produced, P. aeruginosa strains are divided into cytotoxic or invasive strains. Cytotoxic strains are relatively resistant to commercial disinfectants, while invasive strains are more antibiotic resistant. Therefore, contact lens wearers are more predisposed to cytotoxic P. aeruginosa infections, and patients with trauma or previous surgery are more prone to infection by invasive strains. Previous studies with mutant P. aeruginosa strains unable to produce T3SS exotoxins were more susceptible to disinfectants and less able to adhere to soft contact lenses, indicating an essential role of T3SS in bacterial virulence. Invasion of P. aeruginosa intracellularly was found to be associated with control of scaffold protein IQ-domain GTPase-activating protein 1 (IQGAP1) and human corneal epithelial cell tight junctions. Knockdown of IQGAP1 strengthened tight junctions that prevented intracellular survival of invasive P. aeruginosa strains and enhanced corneal epithelial cell survival. These novel findings of the vital role of T3SS in the pathogenesis of pseudomonal MKs will provide new guidelines in both prevention and treatment of this common eye-blinding infection.
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Singh RB, Das S, Chodosh J, Sharma N, Zegans ME, Kowalski RP, Jhanji V. Paradox of complex diversity: Challenges in the diagnosis and management of bacterial keratitis. Prog Retin Eye Res 2021; 88:101028. [PMID: 34813978 DOI: 10.1016/j.preteyeres.2021.101028] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 11/09/2021] [Accepted: 11/12/2021] [Indexed: 12/12/2022]
Abstract
Bacterial keratitis continues to be one of the leading causes of corneal blindness in the developed as well as the developing world, despite swift progress since the dawn of the "anti-biotic era". Although, we are expeditiously developing our understanding about the different causative organisms and associated pathology leading to keratitis, extensive gaps in knowledge continue to dampen the efforts for early and accurate diagnosis, and management in these patients, resulting in poor clinical outcomes. The ability of the causative bacteria to subdue the therapeutic challenge stems from their large genome encoding complex regulatory networks, variety of unique virulence factors, and rapid secretion of tissue damaging proteases and toxins. In this review article, we have provided an overview of the established classical diagnostic techniques and therapeutics for keratitis caused by various bacteria. We have extensively reported our recent in-roads through novel tools for accurate diagnosis of mono- and poly-bacterial corneal infections. Furthermore, we outlined the recent progress by our group and others in understanding the sub-cellular genomic changes that lead to antibiotic resistance in these organisms. Finally, we discussed in detail, the novel therapies and drug delivery systems in development for the efficacious management of bacterial keratitis.
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Affiliation(s)
- Rohan Bir Singh
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA; Department of Ophthalmology, Leiden University Medical Center, 2333, ZA Leiden, the Netherlands
| | - Sujata Das
- Cornea and Anterior Segment Services, LV Prasad Eye Institute, Bhubaneshwar, India
| | - James Chodosh
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Namrata Sharma
- Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Michael E Zegans
- Department of Ophthalmology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Regis P Kowalski
- Department of Ophthalmology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA; The Charles T Campbell Ophthalmic Microbiology Laboratory, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Vishal Jhanji
- Department of Ophthalmology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA; The Charles T Campbell Ophthalmic Microbiology Laboratory, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
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Ung L, Chodosh J. Foundational concepts in the biology of bacterial keratitis. Exp Eye Res 2021; 209:108647. [PMID: 34097906 PMCID: PMC8595513 DOI: 10.1016/j.exer.2021.108647] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 04/28/2021] [Accepted: 05/27/2021] [Indexed: 12/12/2022]
Abstract
Bacterial infections of the cornea, or bacterial keratitis (BK), are notorious for causing rapidly fulminant disease and permanent vision loss, even among treated patients. In the last sixty years, dramatic upward trajectories in the frequency of BK have been observed internationally, driven in large part by the commercialization of hydrogel contact lenses in the late 1960s. Despite this worsening burden of disease, current evidence-based therapies for BK - including broad-spectrum topical antibiotics and, if indicated, topical corticosteroids - fail to salvage vision in a substantial proportion of affected patients. Amid growing concerns of rapidly diminishing antibiotic utility, there has been renewed interest in urgently needed novel treatments that may improve clinical outcomes on an individual and public health level. Bridging the translational gap in the care of BK requires the identification of new therapeutic targets and rational treatment design, but neither of these aims can be achieved without understanding the complex biological processes that determine how bacterial corneal infections arise, progress, and resolve. In this chapter, we synthesize the current wealth of human and animal experimental data that now inform our understanding of basic BK pathophysiology, in context with modern concepts in ocular immunology and microbiology. By identifying the key molecular determinants of clinical disease, we explore how novel treatments can be developed and translated into routine patient care.
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Affiliation(s)
- Lawson Ung
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA; Infectious Disease Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA; Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, MA, USA
| | - James Chodosh
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA; Infectious Disease Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA.
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10
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Enzor R, Bowers EM, Perzia B, Perera C, Palazzolo L, Mammen A, Dhaliwal DK, Kowalski RP, Jhanji V. Comparison of Clinical Features and Treatment Outcomes of Pseudomonas aeruginosa Keratitis in Contact Lens and Non-Contact Lens Wearers. Am J Ophthalmol 2021; 227:1-11. [PMID: 33657419 DOI: 10.1016/j.ajo.2021.02.024] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 02/18/2021] [Accepted: 02/20/2021] [Indexed: 10/22/2022]
Abstract
PURPOSE To compare the outcomes of Pseudomonas aeruginosa keratitis (PAK) in contact lens wearers (CLWs) and non-contact lens wearers (non-CLWs) and identify risk factors for poor visual acuity (VA) outcomes in each group. DESIGN Retrospective cohort study METHODS: Two hundred fourteen consecutive cases of PAK were included between January 2006 and December 2019. Clinical features, microbiologic results, and treatment course were compared between CLW and non-CLW groups. Analyses of clinical features predicting poor final VA were performed. RESULTS This study identified 214 infected eyes in 207 patients with PAK, including 163 eyes (76.2%) in CLWs and 51 eyes (23.8%) in non-CLWs. The average age was 39.2 years in CLWs and 71.9 years in non-CLWs (P < .0001). The average logMAR visual acuity (VA) at presentation was 1.39 in CLWs and 2.17 in non-CLWs (P < .0001); average final VA was 0.76 in CLWs and 1.82 in non-CLWs (P < .0001). Stromal necrosis required a procedural or surgical intervention in 13.5% of CLWs and 49.0% of non-CLWs (P < .0001). A machine learning-based analysis yielded a list of clinical features that most strongly predict a poor VA outcome (worse than 20/40), including worse initial VA, older age, larger size of infiltrate or epithelial defect at presentation, and greater maximal depth of stromal necrosis. CONCLUSIONS Non-CLWs have significantly worse VA outcomes and required a higher rate of surgical intervention, compared with CLWs. Our study elucidates risk factors for poor visual outcomes in non-CLWs with PAK.
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Morin CD, Déziel E, Gauthier J, Levesque RC, Lau GW. An Organ System-Based Synopsis of Pseudomonas aeruginosa Virulence. Virulence 2021; 12:1469-1507. [PMID: 34180343 PMCID: PMC8237970 DOI: 10.1080/21505594.2021.1926408] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Driven in part by its metabolic versatility, high intrinsic antibiotic resistance, and a large repertoire of virulence factors, Pseudomonas aeruginosa is expertly adapted to thrive in a wide variety of environments, and in the process, making it a notorious opportunistic pathogen. Apart from the extensively studied chronic infection in the lungs of people with cystic fibrosis (CF), P. aeruginosa also causes multiple serious infections encompassing essentially all organs of the human body, among others, lung infection in patients with chronic obstructive pulmonary disease, primary ciliary dyskinesia and ventilator-associated pneumonia; bacteremia and sepsis; soft tissue infection in burns, open wounds and postsurgery patients; urinary tract infection; diabetic foot ulcers; chronic suppurative otitis media and otitis externa; and keratitis associated with extended contact lens use. Although well characterized in the context of CF, pathogenic processes mediated by various P. aeruginosa virulence factors in other organ systems remain poorly understood. In this review, we use an organ system-based approach to provide a synopsis of disease mechanisms exerted by P. aeruginosa virulence determinants that contribute to its success as a versatile pathogen.
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Affiliation(s)
- Charles D Morin
- Centre Armand-Frappier Santé Biotechnologie, Institut National De La Recherche Scientifique (INRS), Laval, Quebec, Canada
| | - Eric Déziel
- Centre Armand-Frappier Santé Biotechnologie, Institut National De La Recherche Scientifique (INRS), Laval, Quebec, Canada
| | - Jeff Gauthier
- Département De Microbiologie-infectiologie Et Immunologie, Institut De Biologie Intégrative Et Des Systèmes (IBIS), Université Laval, Québec City, Quebec, Canada
| | - Roger C Levesque
- Département De Microbiologie-infectiologie Et Immunologie, Institut De Biologie Intégrative Et Des Systèmes (IBIS), Université Laval, Québec City, Quebec, Canada
| | - Gee W Lau
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, IL, US
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12
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Khan M, Willcox MDP, Rice SA, Sharma S, Stapleton F. Development of antibiotic resistance in the ocular Pseudomonas aeruginosa clone ST308 over twenty years. Exp Eye Res 2021; 205:108504. [PMID: 33610601 DOI: 10.1016/j.exer.2021.108504] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Revised: 02/07/2021] [Accepted: 02/12/2021] [Indexed: 11/17/2022]
Abstract
Corneal infection caused by a bacteria Pseudomonas aeruginosa is common cause of ocular morbidity. Increasing antibiotic resistance by ocular P. aeruginosa is an emerging concern. In this study the resistome of ocular isolates of Pseudomonas aeruginosa clone ST308 isolated in India in 1997 (PA31, PA32, PA33, PA35 and PA37) and 2018 (PA198 and PA219) were investigated. All the isolates of ST308 had >95% nucleotide similarity. The isolates from 2018 had larger genomes, coding sequences, accessory and pan genes compared to the older isolates from 1997. The 2018 isolate PA219 was resistant to all antibiotics except polymyxin B, while the 2018 isolate PA198 was resistant to ciprofloxacin, levofloxacin, gentamicin and tobramycin. Among the isolates from 1997, five were resistant to gentamicin, tobramycin and ciprofloxacin, four were resistant to levofloxacin while two were resistant to polymyxin B. Twenty-four acquired resistance genes were present in the 2018 isolates compared to 11 in the historical isolates. All isolates contained genes encoding for aminoglycoside (aph(6)-Id, aph(3')-lIb, aph(3″)-Ib), beta-lactam (blaPAO), tetracycline (tet(G)), fosfomycin (fosA), chloramphenicol (catB7), sulphonamide (sul1), quaternary ammonium (qacEdelta1) and fluoroquinolone (crpP) resistance. Isolate PA198 possessed aph(3')-VI, rmtD2, qnrVC1, blaOXA-488, blaPME-1, while PA219 possessed aadA1, rmtB, qnrVC1, aac(6')-Ib-cr, blaTEM-1B, blaVIM-2, blaPAO-1, mph(E), mph(A), msr(E). In both recent isolates qnrVC1 was present in Tn3 transposon. In 219 blaTEM-1 was carried on a transposon and blaOXA-10 on a class 1 integron. There were no notable differences in the number of single nucleotide polymorphisms, but recent isolates carried more insertions and deletions in their genes. These findings suggest that genomes of P. aeruginosa ocular clonal strains with >95% nucleotide identity isolated twenty years apart had changed over time with the acquisition of resistance genes. The pattern of gene mutations also varied with more insertions and deletions in their chromosomal genes which confer resistance to antibiotics.
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Affiliation(s)
- Mahjabeen Khan
- School of Optometry and Vision Science, UNSW, Sydney, Australia.
| | - Mark D P Willcox
- School of Optometry and Vision Science, UNSW, Sydney, Australia.
| | - Scott A Rice
- The Singapore Centre for Environment Life Sciences Engineering (SCELSE), The School of Biological Sciences, Nanyang Technological University Singapore and the Ithree Institute, The University of Technology Sydney, Sydney, Australia.
| | | | - Fiona Stapleton
- School of Optometry and Vision Science, UNSW, Sydney, Australia.
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13
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Kennedy SM, Deshpande P, Gallagher AG, Horsburgh MJ, Allison HE, Kaye SB, Wellings DA, Williams RL. Antimicrobial Activity of Poly-epsilon-lysine Peptide Hydrogels Against Pseudomonas aeruginosa. Invest Ophthalmol Vis Sci 2021; 61:18. [PMID: 32776141 PMCID: PMC7441358 DOI: 10.1167/iovs.61.10.18] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Purpose To determine the antimicrobial activity of poly-epsilon-lysine (pɛK) functionalization of hydrogels against Pseudomonas aeruginosa. Methods Antimicrobial activities of pɛK and pɛK+ hydrogels were tested against both keratitis and a laboratory strain of Paeruginosa at a range of inocula sizes, over 4 and 24 hours. The number of viable CFU on pɛK and pɛK+ hydrogels or commercial contact lenses (CL) was investigated. Ex vivo porcine corneas were inoculated with Paeruginosa PAO1 (103 CFU) and incubated with pɛK+ hydrogels or commercial hydrogel CL for 24 hours and the effects of infection determined. Results PɛK+ hydrogels showed log reductions in viable CFU compared with pɛK hydrogels for all Paeruginosa strains, depending on inocula sizes and incubation time. After 24 hours pɛK+ hydrogels showed >5 and >7.5 log reduction in CFU compared with commercial hydrogel CL at 103 and 106 CFU, respectively. In an ex vivo porcine corneal infection model, pɛK+ hydrogels led to a significant decrease in viable PAO1 CFU and histologic analysis indicated a decreased infiltration of PAO1 into the stroma. Conclusions PɛK+ hydrogels demonstrated enhanced antimicrobial activity versus nonfunctionalized pɛK hydrogels against clinically relevant Paeruginosa strains. PɛK+ hydrogels have the potential to be used as a bandage CL with innate antimicrobial characteristics to minimize the risk of microbial keratitis.
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Affiliation(s)
- Stephnie M Kennedy
- Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Pallavi Deshpande
- Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
| | | | - Malcolm J Horsburgh
- Department of Infection Biology and Microbiomes, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Heather E Allison
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Stephen B Kaye
- Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
| | | | - Rachel L Williams
- Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
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Kandasamy K, Thirumalmuthu K, Prajna NV, Lalitha P, Mohankumar V, Devarajan B. Comparative genomics of ocular Pseudomonas aeruginosa strains from keratitis patients with different clinical outcomes. Genomics 2020; 112:4769-4776. [DOI: 10.1016/j.ygeno.2020.08.032] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 08/19/2020] [Accepted: 08/27/2020] [Indexed: 12/21/2022]
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15
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Rodrigues YC, Furlaneto IP, Maciel AHP, Quaresma AJPG, de Matos ECO, Conceição ML, Vieira MCDS, Brabo GLDC, Sarges EDSNF, Lima LNGC, Lima KVB. High prevalence of atypical virulotype and genetically diverse background among Pseudomonas aeruginosa isolates from a referral hospital in the Brazilian Amazon. PLoS One 2020; 15:e0238741. [PMID: 32911510 PMCID: PMC7482967 DOI: 10.1371/journal.pone.0238741] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Accepted: 08/21/2020] [Indexed: 12/23/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen causing different types of infections, particularly in intensive care unit patients. Characteristics that favor its persistence artificial environments are related to its high adaptability, wide arsenal of virulence factors and resistance to several antimicrobial classes. Among the several virulence determinants, T3SS stands as the most important due to the clinical impact of exoS and exoU genes in patient’s outcome. The molecular characterization of P. aeruginosa isolates helps in the comprehension of transmission dynamics and enhance knowledge of virulence and resistance roles in infection process. In the present study, we investigated virulence and resistance properties and the genetic background of P. aeruginosa isolated from ICUs patients at a referral hospital in Brazilian Amazon. A total of 54 P. aeruginosa isolates were characterized by detecting 19 virulence-related genes, antimicrobial susceptibility testing, molecular detection of β-lactamase-encoding genes and genotyping by MLST and rep-PCR. Our findings showed high prevalence of virulence-related markers, where 53.7% of the isolates presented at least 17 genes among the 19 investigated (P = 0.01). The rare exoS+/exoU+ cytotoxic virulotype was detected in 55.6% of isolates. Antimicrobial susceptibility testing revealed percentages of antibiotic resistance above 50% to carbapenems, cephalosporins and fluoroquinolones associated to MDR/XDR isolates. Isolates harboring both blaSPM-1 and blaOXA genes were also detected. Genotyping methods demonstrated a wide genetic diversity of strains spread among the different intensive care units, circulation of international MDR/XDR high-risk clones (ST111, ST235, ST244 and ST277) and emergence of seven novel MLST lineages. Finally, our findings highlight the circulation of strains with high virulence potential and resistance to antimicrobials and may be useful on comprehension of pathogenicity process, treatment guidance and establishment of strategies to control the spread of epidemic P. aeruginosa strains.
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Affiliation(s)
- Yan Corrêa Rodrigues
- Programa de Pós-graduação em Biologia Parasitária na Amazônia, Centro de Ciências Biológicas e da Saúde, Universidade do Estado do Pará (UEPA), Belém, Pará, Brazil
- * E-mail: (YCR); (KVBL)
| | - Ismari Perini Furlaneto
- Programa de Pós-graduação em Educação em Saúde, Centro Universitário do Pará (CESUPA), Belém, Pará Brazil
| | - Arthur Henrique Pinto Maciel
- Laboratório de Biologia Molecular, Seção de Bacteriologia e Micologia, Instituto Evandro Chagas (IEC), Ministério da Saúde, Ananindeua, Pará, Brazil
| | - Ana Judith Pires Garcia Quaresma
- Laboratório de Biologia Molecular, Seção de Bacteriologia e Micologia, Instituto Evandro Chagas (IEC), Ministério da Saúde, Ananindeua, Pará, Brazil
| | - Eliseth Costa Oliveira de Matos
- Departamento de Patologia, Centro de Ciências Biológicas e da Saúde, Universidade do Estado do Pará (UEPA), Belém, Pará, Brazil
| | - Marília Lima Conceição
- Programa de Pós-graduação em Biologia Parasitária na Amazônia, Centro de Ciências Biológicas e da Saúde, Universidade do Estado do Pará (UEPA), Belém, Pará, Brazil
| | - Marcelo Cleyton da Silva Vieira
- Laboratório de Biologia Molecular, Seção de Bacteriologia e Micologia, Instituto Evandro Chagas (IEC), Ministério da Saúde, Ananindeua, Pará, Brazil
| | - Giulia Leão da Cunha Brabo
- Laboratório de Biologia Molecular, Seção de Bacteriologia e Micologia, Instituto Evandro Chagas (IEC), Ministério da Saúde, Ananindeua, Pará, Brazil
| | | | - Luana Nepomuceno Godim Costa Lima
- Programa de Pós-graduação em Biologia Parasitária na Amazônia, Centro de Ciências Biológicas e da Saúde, Universidade do Estado do Pará (UEPA), Belém, Pará, Brazil
- Laboratório de Biologia Molecular, Seção de Bacteriologia e Micologia, Instituto Evandro Chagas (IEC), Ministério da Saúde, Ananindeua, Pará, Brazil
| | - Karla Valéria Batista Lima
- Programa de Pós-graduação em Biologia Parasitária na Amazônia, Centro de Ciências Biológicas e da Saúde, Universidade do Estado do Pará (UEPA), Belém, Pará, Brazil
- Laboratório de Biologia Molecular, Seção de Bacteriologia e Micologia, Instituto Evandro Chagas (IEC), Ministério da Saúde, Ananindeua, Pará, Brazil
- * E-mail: (YCR); (KVBL)
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Shen EP, Chu HS, Hsieh YT, Chen WL, Chang SC, Hu FR. Analysis of P. aeruginosa disinfectant sensitivity and microbial adhesions to worn cosmetic contact lenses. Cont Lens Anterior Eye 2020; 43:338-344. [DOI: 10.1016/j.clae.2019.10.137] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 10/15/2019] [Accepted: 10/27/2019] [Indexed: 12/22/2022]
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17
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Zhang Y, Pan X, Liao S, Jiang C, Wang L, Tang Y, Wu G, Dai G, Chen L. Quantitative Proteomics Reveals the Mechanism of Silver Nanoparticles against Multidrug-Resistant Pseudomonas aeruginosa Biofilms. J Proteome Res 2020; 19:3109-3122. [PMID: 32567865 DOI: 10.1021/acs.jproteome.0c00114] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The decline of clinically effective antibiotics has made it necessary to develop more effective antimicrobial agents, especially for refractory biofilm-related infections. Silver nanoparticles (AgNPs) are a new type of antimicrobial agent that can eradicate biofilms and reduce bacterial resistance, but its anti-biofilm mechanism has not been elucidated. In this study, we investigated the molecular mechanism of AgNPs against multidrug-resistant Pseudomonas aeruginosa by means of anti-biofilm tests, scanning electron microscopy (SEM), and tandem mass tag (TMT)-labeled quantitative proteomics. The results of anti-biofilm tests demonstrated that AgNPs inhibited the formation of P. aeruginosa biofilm and disrupted its preformed biofilm. SEM showed that when exposed to AgNPs, the structure of the P. aeruginosa biofilm was destroyed, along with significant reduction of its biomass. TMT-labeled quantitative proteomic analysis revealed that AgNPs could defeat the P. aeruginosa biofilm in multiple ways by inhibiting its adhesion and motility, stimulating strong oxidative stress response, destroying iron homeostasis, blocking aerobic and anaerobic respiration, and affecting quorum sensing systems. Our findings offer a new insight into clarifying the mechanism of AgNPs against biofilms, thus providing a theoretical basis for its clinical application.
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Affiliation(s)
- Yapeng Zhang
- Department of Medical Microbiology, School of Basic Medical Sciences, Central South University, Changsha 410013, China
| | - Xuanhe Pan
- Department of Medical Microbiology, School of Basic Medical Sciences, Central South University, Changsha 410013, China
| | - Shijing Liao
- Department of Clinical Laboratory, The First People's Hospital of Yueyang, Yueyang 414000, China
| | - Congyuan Jiang
- Hunan Anson Biotechnology Company Ltd., Changsha 410008, China
| | - Linqian Wang
- Department of Clinical Laboratory, Hunan Cancer Hospital, The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha 410013, China
| | - Yurong Tang
- Department of Medical Microbiology, School of Basic Medical Sciences, Central South University, Changsha 410013, China
| | - Guojun Wu
- Department of Medical Microbiology, School of Basic Medical Sciences, Central South University, Changsha 410013, China
| | - Gan Dai
- Department of Medical Microbiology, School of Basic Medical Sciences, Central South University, Changsha 410013, China
| | - Liyu Chen
- Department of Medical Microbiology, School of Basic Medical Sciences, Central South University, Changsha 410013, China
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18
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Panayidou S, Georgiades K, Christofi T, Tamana S, Promponas VJ, Apidianakis Y. Pseudomonas aeruginosa core metabolism exerts a widespread growth-independent control on virulence. Sci Rep 2020; 10:9505. [PMID: 32528034 PMCID: PMC7289854 DOI: 10.1038/s41598-020-66194-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 05/13/2020] [Indexed: 02/04/2023] Open
Abstract
To assess the role of core metabolism genes in bacterial virulence - independently of their effect on growth - we correlated the genome, the transcriptome and the pathogenicity in flies and mice of 30 fully sequenced Pseudomonas strains. Gene presence correlates robustly with pathogenicity differences among all Pseudomonas species, but not among the P. aeruginosa strains. However, gene expression differences are evident between highly and lowly pathogenic P. aeruginosa strains in multiple virulence factors and a few metabolism genes. Moreover, 16.5%, a noticeable fraction of the core metabolism genes of P. aeruginosa strain PA14 (compared to 8.5% of the non-metabolic genes tested), appear necessary for full virulence when mutated. Most of these virulence-defective core metabolism mutants are compromised in at least one key virulence mechanism independently of auxotrophy. A pathway level analysis of PA14 core metabolism, uncovers beta-oxidation and the biosynthesis of amino-acids, succinate, citramalate, and chorismate to be important for full virulence. Strikingly, the relative expression among P. aeruginosa strains of genes belonging in these metabolic pathways is indicative of their pathogenicity. Thus, P. aeruginosa strain-to-strain virulence variation, remains largely obscure at the genome level, but can be dissected at the pathway level via functional transcriptomics of core metabolism.
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Affiliation(s)
- Stavria Panayidou
- Infection and Cancer Laboratory, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
| | - Kaliopi Georgiades
- Infection and Cancer Laboratory, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus.,Bioinformatics Research Laboratory, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
| | - Theodoulakis Christofi
- Infection and Cancer Laboratory, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
| | - Stella Tamana
- Bioinformatics Research Laboratory, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
| | - Vasilis J Promponas
- Bioinformatics Research Laboratory, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus.
| | - Yiorgos Apidianakis
- Infection and Cancer Laboratory, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus.
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19
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Dave A, Samarth A, Karolia R, Sharma S, Karunakaran E, Partridge L, MacNeil S, Monk PN, Garg P, Roy S. Characterization of Ocular Clinical Isolates of Pseudomonas aeruginosa from Non-Contact Lens Related Keratitis Patients from South India. Microorganisms 2020; 8:microorganisms8020260. [PMID: 32075262 PMCID: PMC7074794 DOI: 10.3390/microorganisms8020260] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 02/10/2020] [Accepted: 02/13/2020] [Indexed: 12/25/2022] Open
Abstract
P. aeruginosa is the most common Gram-negative organism causing bacterial keratitis. Pseudomonas utilizes various virulence mechanisms to adhere and colonize in the host tissue. In the present study, we examined virulence factors associated with thirty-four clinical P. aeruginosa isolates collected from keratitis patients seeking care at L V Prasad Eye Institute, Hyderabad. The virulence-associated genes in all the isolates were genotyped and characteristics such as antibiotic susceptibility, biofilm formation, swarming motility, pyoverdine production and cell cytotoxicity were analyzed. All the isolates showed the presence of genes related to biofilm formation, alkaline proteases and elastases; however, there was a difference in the presence of genes related to the type III secretion system (T3SS). A higher prevalence of exoU+ genotype was noted in the drug-resistant isolates. All the isolates were capable of forming biofilms and more than 70% of the isolates showed good swarming motility. Pyoverdine production was not associated with the T3SS genotype. In the cytotoxicity assay, the presence of exoS,exoU or both resulted in higher cytotoxicity compared to the absence of both the genes. Overall, our results suggest that the T3SS profile is a good indicator of P. aeruginosa virulence characteristics and the isolates lacking the effector genes may have evolved alternate mechanisms of colonization in the host.
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Affiliation(s)
- Alpana Dave
- Prof. Brien Holden Eye Research Centre, LV Prasad Eye Institute, Hyderabad 500034, India; (A.D.); (A.S.); (P.G.)
| | - Apurwa Samarth
- Prof. Brien Holden Eye Research Centre, LV Prasad Eye Institute, Hyderabad 500034, India; (A.D.); (A.S.); (P.G.)
| | - Roshni Karolia
- Jhaveri Microbiology Centre, LV Prasad Eye Institute, Hyderabad 500034, India; (R.K.); (S.S.)
| | - Savitri Sharma
- Jhaveri Microbiology Centre, LV Prasad Eye Institute, Hyderabad 500034, India; (R.K.); (S.S.)
| | - Esther Karunakaran
- Department of Chemical and Biological Engineering, University of Sheffield, Sheffield S102TG, UK;
| | - Lynda Partridge
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S102TG, UK;
| | - Sheila MacNeil
- Department of Material Science and Engineering, University of Sheffield, Sheffield S102TG, UK;
| | - Peter N. Monk
- Department of Infection Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield S102RX, UK;
| | - Prashant Garg
- Prof. Brien Holden Eye Research Centre, LV Prasad Eye Institute, Hyderabad 500034, India; (A.D.); (A.S.); (P.G.)
| | - Sanhita Roy
- Prof. Brien Holden Eye Research Centre, LV Prasad Eye Institute, Hyderabad 500034, India; (A.D.); (A.S.); (P.G.)
- Correspondence: ; Tel.: +91-40-30612529; Fax: +91-40-30612535
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20
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Abstract
Pseudomonas aeruginosa, a versatile Gram-negative pathogen that can cause a wide range of infections, is the most common causative agent in cases of bacterial keratitis associated with contact-lens use. Corneal infections with P. aeruginosa often have poor clinical outcomes and can result in long and costly treatments. During the infection process, the pathogen exploits its large genome, encoding complex regulatory networks and a wide range of virulence factors, including motility and the secretion of various proteases and toxins. Although antibiotic resistance levels in the UK are low, higher levels have been seen in some other countries. In the face of increasing antibiotic resistance, alternative therapeutic approaches such as antivirulence strategies and phage therapy are being developed. There is increasing evidence to suggest that keratitis infections are associated with a phylogenetic subgroup of P. aeruginosa isolates carrying the gene encoding the potent cytotoxin exotoxin U, one of two mutually exclusive exotoxins secreted via the type III secretion system. The mechanisms behind this association are unclear, but understanding the genetic differences that predispose P. aeruginosa to cause corneal infections may allow for the development of targeted and more effective future treatments to reduce the morbidity of P. aeruginosa keratitis. In order to minimize the risk of severe P. aeruginosa eye infections, a wide range of contact-lens disinfection solutions are available. Constant exposure to biocides at a range of concentrations, from sub-inhibitory to inhibitory, could contribute to the development of resistance to both antibiotics and disinfectants.
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Affiliation(s)
- Yasmin Hilliam
- Department of Clinical Infection, Microbiology, and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, L69 7BE, UK
| | - Stephen Kaye
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, L7 8TX, UK
| | - Craig Winstanley
- Department of Clinical Infection, Microbiology, and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, L69 7BE, UK
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21
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Kashyap PL, Kumar S, Kumar RS, Tripathi R, Sharma P, Sharma A, Jasrotia P, Singh GP. Identification of Novel Microsatellite Markers to Assess the Population Structure and Genetic Differentiation of Ustilago hordei Causing Covered Smut of Barley. Front Microbiol 2020; 10:2929. [PMID: 32010068 PMCID: PMC6974468 DOI: 10.3389/fmicb.2019.02929] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 12/05/2019] [Indexed: 12/03/2022] Open
Abstract
Barley covered smut (CS) pathogen Ustilago hordei genome was mined for microsatellite distribution and their application in defining population structure and genetic variation. To dissect the molecular variation and genetic structure of U. hordei, 59 fungal isolates representing two distinct agro-ecological zones of India were analyzed by employing simple sequence repeats (SSRs). Using bioinformatic approaches, a total of 100,239 and 137,442 microsatellites were identified from 20.13 and 26.94 Mb of assembled genomic sequences of Uh364 and Uh4857-4 isolates of U. hordei, respectively. Penta-nucleotides (31.29 and 29.75%) followed by tri-nucleotide (28.27 and 29.88%) were most prevalent in both the genomes. Out of them, 15 polymorphic microsatellites showing conservancies in both the genomes were selected for exploring population genetic structure of U. hordei. An average of two alleles per microsatellite marker was generated with band size ranging from 180 to 850 bp. Polymorphic information content (PIC) varied between 0.095 and 0.37. Fifty-nine isolates were distributed in two distinct groups with about 65% genetic similarity according to UPGMA clustering and population structure analysis (K = 2). Gene flow analysis (Nm = 1.009) reflected moderate gene flow among the analyzed population. An analysis of molecular variance (AMOVA) displayed high level of genetic variation within population (87%) and low variation among populations (13%). Linkage disequilibrium (LD) analysis indicated positively significant but relatively low standardized index of association (SIA) value in both the population sets (SIA = 0.181), advocating a state of LD with epidemic population structure. In conclusion, the newly developed neutral SSR markers are highly polymorphic within U. hordei and will be useful for revealing evolutionary history and providing deep insight into the population dynamics of U. hordei in India as well as facilitating developing management strategies for CS of barley.
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Fleiszig SMJ, Kroken AR, Nieto V, Grosser MR, Wan SJ, Metruccio MME, Evans DJ. Contact lens-related corneal infection: Intrinsic resistance and its compromise. Prog Retin Eye Res 2019; 76:100804. [PMID: 31756497 DOI: 10.1016/j.preteyeres.2019.100804] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Revised: 11/05/2019] [Accepted: 11/12/2019] [Indexed: 12/20/2022]
Abstract
Contact lenses represent a widely utilized form of vision correction with more than 140 million wearers worldwide. Although generally well-tolerated, contact lenses can cause corneal infection (microbial keratitis), with an approximate annualized incidence ranging from ~2 to ~20 cases per 10,000 wearers, and sometimes resulting in permanent vision loss. Research suggests that the pathogenesis of contact lens-associated microbial keratitis is complex and multifactorial, likely requiring multiple conspiring factors that compromise the intrinsic resistance of a healthy cornea to infection. Here, we outline our perspective of the mechanisms by which contact lens wear sometimes renders the cornea susceptible to infection, focusing primarily on our own research efforts during the past three decades. This has included studies of host factors underlying the constitutive barrier function of the healthy cornea, its response to bacterial challenge when intrinsic resistance is not compromised, pathogen virulence mechanisms, and the effects of contact lens wear that alter the outcome of host-microbe interactions. For almost all of this work, we have utilized the bacterium Pseudomonas aeruginosa because it is the leading cause of lens-related microbial keratitis. While not yet common among corneal isolates, clinical isolates of P. aeruginosa have emerged that are resistant to virtually all currently available antibiotics, leading the United States CDC (Centers for Disease Control) to add P. aeruginosa to its list of most serious threats. Compounding this concern, the development of advanced contact lenses for biosensing and augmented reality, together with the escalating incidence of myopia, could portent an epidemic of vision-threatening corneal infections in the future. Thankfully, technological advances in genomics, proteomics, metabolomics and imaging combined with emerging models of contact lens-associated P. aeruginosa infection hold promise for solving the problem - and possibly life-threatening infections impacting other tissues.
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Affiliation(s)
- Suzanne M J Fleiszig
- School of Optometry, University of California, Berkeley, CA, USA; Graduate Group in Vision Science, University of California, Berkeley, CA, USA; Graduate Groups in Microbiology and Infectious Diseases & Immunity, University of California, Berkeley, CA, USA.
| | - Abby R Kroken
- School of Optometry, University of California, Berkeley, CA, USA
| | - Vincent Nieto
- School of Optometry, University of California, Berkeley, CA, USA
| | | | - Stephanie J Wan
- Graduate Group in Vision Science, University of California, Berkeley, CA, USA
| | | | - David J Evans
- School of Optometry, University of California, Berkeley, CA, USA; College of Pharmacy, Touro University California, Vallejo, CA, USA
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23
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Lee JH, Jeon J, Bai F, Jin S, Wu W, Ha UH. The Pseudomonas aeruginosa HSP70-like protein DnaK induces IL-1β expression via TLR4-dependent activation of the NF-κB and JNK signaling pathways. Comp Immunol Microbiol Infect Dis 2019; 67:101373. [PMID: 31704499 DOI: 10.1016/j.cimid.2019.101373] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 10/12/2019] [Accepted: 10/15/2019] [Indexed: 12/18/2022]
Abstract
IL-1β expression is increased in response to P. aeruginosa infection, but the responsible proteins have not been clearly elucidated. Here, we demonstrate for the first time that IL-1β expression is induced in response to the heat shock protein 70-like protein DnaK. Treatment with recombinant DnaK (rDnaK) increased IL-1β expression in a dose- and time-dependent manner, and the release of mature IL-1β in response to rDnaK was detected to an extent similar to that stimulated by the well-known agonists, lipopolysaccharide and nigericin. rDnaK-mediated IL-1β expression was driven by the NF-κB signaling pathway. In addition, expression was controlled by the JNK signaling pathway, although these two signaling cascades act independently upon rDnaK stimulation. Finally, rDnaK-induced IL-1β expression was initiated via the action of TLR4. Taken together, the data reveal that P. aeruginosa-derived DnaK induces expression of IL-1β via TLR4-dependent activation of the NF-κB and JNK signaling pathways.
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Affiliation(s)
- Jung-Hoon Lee
- Department of Biotechnology and Bioinformatics, Korea University, Sejong 30019, Republic of Korea
| | - Jisu Jeon
- Department of Biotechnology and Bioinformatics, Korea University, Sejong 30019, Republic of Korea
| | - Fang Bai
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, Nankai University, Tianjin 300071, China
| | - Shouguang Jin
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, Florida 32610, USA
| | - Weihui Wu
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, Nankai University, Tianjin 300071, China
| | - Un-Hwan Ha
- Department of Biotechnology and Bioinformatics, Korea University, Sejong 30019, Republic of Korea.
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24
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Ozer EA, Nnah E, Didelot X, Whitaker RJ, Hauser AR. The Population Structure of Pseudomonas aeruginosa Is Characterized by Genetic Isolation of exoU+ and exoS+ Lineages. Genome Biol Evol 2019; 11:1780-1796. [PMID: 31173069 PMCID: PMC6690169 DOI: 10.1093/gbe/evz119] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/05/2019] [Indexed: 02/06/2023] Open
Abstract
The diversification of microbial populations may be driven by many factors including adaptation to distinct ecological niches and barriers to recombination. We examined the population structure of the bacterial pathogen Pseudomonas aeruginosa by analyzing whole-genome sequences of 739 isolates from diverse sources. We confirmed that the population structure of P. aeruginosa consists of two major groups (referred to as Groups A and B) and at least two minor groups (Groups C1 and C2). Evidence for frequent intragroup but limited intergroup recombination in the core genome was observed, consistent with sexual isolation of the groups. Likewise, accessory genome analysis demonstrated more gene flow within Groups A and B than between these groups, and a few accessory genomic elements were nearly specific to one or the other group. In particular, the exoS gene was highly overrepresented in Group A compared with Group B isolates (99.4% vs. 1.1%) and the exoU gene was highly overrepresented in Group B compared with Group A isolates (95.2% vs. 1.8%). The exoS and exoU genes encode effector proteins secreted by the P. aeruginosa type III secretion system. Together these results suggest that the major P. aeruginosa groups defined in part by the exoS and exoU genes are divergent from each other, and that these groups are genetically isolated and may be ecologically distinct. Although both groups were globally distributed and caused human infections, certain groups predominated in some clinical contexts.
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Affiliation(s)
- Egon A Ozer
- Division of Infectious Diseases, Department of Medicine, Northwestern University Feinberg School of Medicine
| | - Ekpeno Nnah
- Lurie Children's Hospital, Chicago, Illinois
| | - Xavier Didelot
- School of Life Sciences and Department of Statistics, University of Warwick, Coventry, United Kingdom
| | - Rachel J Whitaker
- Department of Microbiology and the Carl R. Woese Institute of Genomic Biology, University of Illinois, Urbana-Champaign
| | - Alan R Hauser
- Division of Infectious Diseases, Department of Medicine, Northwestern University Feinberg School of Medicine.,Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine
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25
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Development of a Broad-Spectrum Antimicrobial Combination for the Treatment of Staphylococcus aureus and Pseudomonas aeruginosa Corneal Infections. Antimicrob Agents Chemother 2018; 63:AAC.01929-18. [PMID: 30420484 DOI: 10.1128/aac.01929-18] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 10/25/2018] [Indexed: 10/28/2022] Open
Abstract
Staphylococcus aureus and Pseudomonas aeruginosa are two of the most common causes of bacterial keratitis and corresponding corneal blindness. Accordingly, such infections are predominantly treated with broad-spectrum fluoroquinolones, such as moxifloxacin. Yet, the rising fluoroquinolone resistance has necessitated the development of alternative therapeutic options. Herein, we describe the development of a polymyxin B-trimethoprim (PT) ophthalmic formulation containing the antibiotic rifampin, which exhibits synergistic antimicrobial activity toward a panel of contemporary ocular clinical S. aureus and P. aeruginosa isolates, low spontaneous resistance frequency, and in vitro bactericidal kinetics and antibiofilm activities equaling or exceeding the antimicrobial properties of moxifloxacin. The PT plus rifampin combination also demonstrated increased efficacy in comparison to those of either commercial PT or moxifloxacin in a murine keratitis model of infection, resulting in bacterial clearance of 70% in the animals treated. These results suggest that the combination of PT and rifampin may represent a novel antimicrobial agent in the treatment of bacterial keratitis.
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Environmental and Clinical Pseudomonas aeruginosa Isolates with Pooled Presence of exo S, exo U, exo T and exo Y genes. JOURNAL OF PURE AND APPLIED MICROBIOLOGY 2018. [DOI: 10.22207/jpam.12.3.10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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27
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Rutherford V, Yom K, Ozer EA, Pura O, Hughes A, Murphy KR, Cudzilo L, Mitchel D, Hauser AR. Environmental reservoirs for exoS+ and exoU+ strains of Pseudomonas aeruginosa. ENVIRONMENTAL MICROBIOLOGY REPORTS 2018; 10:485-492. [PMID: 29687624 PMCID: PMC6108916 DOI: 10.1111/1758-2229.12653] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 04/15/2018] [Indexed: 06/08/2023]
Abstract
Pseudomonas aeruginosa uses its type III secretion system to inject the effector proteins ExoS and ExoU into eukaryotic cells, which subverts these cells to the bacterium's advantage and contributes to severe infections. We studied the environmental reservoirs of exoS+ and exoU+ strains of P. aeruginosa by collecting water, soil, moist substrates and plant samples from environments in the Chicago region and neighbouring states. Whole-genome sequencing was used to determine the phylogeny and type III secretion system genotypes of 120 environmental isolates. No correlation existed between geographic separation of isolates and their genetic relatedness, which confirmed previous findings of both high genetic diversity within a single site and the widespread distribution of P. aeruginosa clonal complexes. After excluding clonal isolates cultured from the same samples, 74 exoS+ isolates and 16 exoU+ isolates remained. Of the exoS+ isolates, 41 (55%) were from natural environmental sites and 33 (45%) were from man-made sites. Of the exoU+ isolates, only 3 (19%) were from natural environmental sites and 13 (81%) were from man-made sites (p < 0.05). These findings suggest that man-made water systems may be a reservoir from which patients acquire exoU+ P. aeruginosa strains.
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Affiliation(s)
- Victoria Rutherford
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Kelly Yom
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Egon A. Ozer
- Department of Medicine, Division of Infectious Diseases, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Olivia Pura
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Ami Hughes
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Katherine R. Murphy
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Laura Cudzilo
- Department of Biology, St. John’s University, Collegeville, Minnesota
| | - David Mitchel
- Department of Biology, St. John’s University, Collegeville, Minnesota
| | - Alan R. Hauser
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
- Department of Medicine, Division of Infectious Diseases, Northwestern University Feinberg School of Medicine, Chicago, Illinois
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28
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Doustdar F, Karimi F, Abedinyfar Z, Amoli FA, Goudarzi H. Genetic features of Pseudomonas aeruginosa isolates associated with eye infections referred to Farabi Hospital, Tehran, Iran. Int Ophthalmol 2018; 39:1581-1587. [PMID: 29982958 DOI: 10.1007/s10792-018-0980-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 06/18/2018] [Indexed: 11/30/2022]
Abstract
BACKGROUND Pseudomonas is the most common cause of microbial keratitis especially in people who use contact lens. The virulence of Pseudomonas aeruginosa in different eye infections is associated with different virulence factors . METHODS In this study, 54 P. aeruginosa isolates including 39 isolates from keratitis and 15 isolates from conjunctivitis were evaluated for their ability to form biofilm, production of protease, elastase, alkaline protease and their antibiotic-resistant patterns. The distribution of the exoS and exoU genes in the test strains were determined using PCR assays. RESULTS Most of the eye infections (90.74%) were seen in people who used contact lenses, and in most of patients (72.22%), the infection was presented as keratitis. None of the isolates were resistant to a single antibiotic as tested. Multidrug resistance (MDR) was detected in two isolates (3.5%) which were resistant to more than one category of antibiotics. The exoU+/exoS+ isolates were in majority although in total, compared to exoS, there were more exoU in a greater number of samples. Most of the strains produce elastase but among all of ocular isolates, only 5.8% of the strains showed alkaline protease activity. Most of the ocular isolates were not capable of producing biofilm. CONCLUSIONS In our study, a high prevalence of virulence factors was observed in P. aeruginosa isolates from contact lens wearer with keratitis. As the P. aeruginosa isolates from different infection origins and different geographic region may have different virulence factors, having a better perception of these differences could help to improve development of clinical instructions for the control of keratitis.
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Affiliation(s)
- Farahnoosh Doustdar
- Department of Microbiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | - Fatemeh Karimi
- Department of Biology, Faculty of Science, Azarbaijan Shahid Madani University, Tabriz, Iran
| | - Zohreh Abedinyfar
- Department of Microbiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Fahimeh Asadi Amoli
- Department of Pathology, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Hossein Goudarzi
- Department of Microbiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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29
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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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30
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Wilkinson HN, Iveson S, Catherall P, Hardman MJ. A Novel Silver Bioactive Glass Elicits Antimicrobial Efficacy Against Pseudomonas aeruginosa and Staphylococcus aureus in an ex Vivo Skin Wound Biofilm Model. Front Microbiol 2018; 9:1450. [PMID: 30018606 PMCID: PMC6037725 DOI: 10.3389/fmicb.2018.01450] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 06/11/2018] [Indexed: 11/28/2022] Open
Abstract
Biofilm infection is now understood to be a potent contributor to the recalcitrant nature of chronic wounds. Bacterial biofilms evade the host immune response and show increased resistance to antibiotics. Along with improvements in antibiotic stewardship, effective new anti-biofilm therapies are urgently needed for effective wound management. Previous studies have shown that bioactive glass (Bg) is able to promote healing with moderate bactericidal activity. Here we tested the antimicrobial efficacy of a novel BG incorporating silver (BgAg), against both planktonic and biofilm forms of the wound-relevant bacteria Pseudomonas aeruginosa and Staphylococcus aureus. BgAg was stable, long lasting, and potently effective against planktonic bacteria in time-kill assays (6-log reduction in bacterial viability within 2 h) and in agar diffusion assays. BgAg reduced bacterial load in a physiologically relevant ex vivo porcine wound biofilm model; P. aeruginosa (2-log reduction) and S. aureus (3-log reduction). BgAg also conferred strong effects against P. aeruginosa biofilm virulence, reducing both protease activity and virulence gene expression. Co-culture biofilms appeared more resistant to BgAg, where a selective reduction in S. aureus was observed. Finally, BgAg was shown to benefit the host response to biofilm infection, directly reducing host tissue cell death. Taken together, the findings provide evidence that BgAg elicits potent antimicrobial effects against planktonic and single-species biofilms, with beneficial effects on the host tissue response. Further investigations are required to elucidate the specific consequences of BG administration on polymicrobial biofilms, and further explore the effects on host-microbe interactions.
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Affiliation(s)
| | - Sammi Iveson
- School of Life Sciences, University of Hull, Hull, United Kingdom
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31
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Corich L, Busetti M, Petix V, Passamonti S, Bandiera A. Evaluation of a biomimetic 3D substrate based on the Human Elastin-like Polypeptides (HELPs) model system for elastolytic activity detection. J Biotechnol 2017. [PMID: 28624377 DOI: 10.1016/j.jbiotec.2017.06.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Elastin is a fibrous protein that confers elasticity to tissues such as skin, arteries and lung. It is extensively cross-linked, highly hydrophobic and insoluble. Nevertheless, elastin can be hydrolysed by bacterial proteases in infectious diseases, resulting in more or less severe tissue damage. Thus, development of substrates able to reliably and specifically detect pathogen-secreted elastolytic activity is needed to improve the in vitro evaluation of the injury that bacterial proteases may provoke. In this work, two human biomimetic elastin polypeptides, HELP and HELP1, as well as the matrices derived from HELP, have been probed as substrates for elastolytic activity detection. Thirty strains of Pseudomonas aeruginosa isolated from cystic fibrosis patients were analyzed in parallel with standard substrates, to detect proteolytic and elastolytic activity. Results point to the HELP-based 3D matrix as an interesting biomimetic model of elastin to assess bacterial elastolytic activity in vitro. Moreover, this model substrate enables to further elucidate the mechanism underlying elastin degradation at molecular level, as well as to develop biomimetic material-based devices responsive to external stimuli.
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Affiliation(s)
- Lucia Corich
- Department of Life Sciences, University of Trieste, 34127, Trieste, Italy.
| | - Marina Busetti
- Microbiology Unit, University Hospital ASUITS, 34149, Trieste, Italy
| | - Vincenzo Petix
- Institute for Maternal and Child Health IRCCS Burlo Garofolo, 34137, Trieste, Italy
| | - Sabina Passamonti
- Department of Life Sciences, University of Trieste, 34127, Trieste, Italy
| | - Antonella Bandiera
- Department of Life Sciences, University of Trieste, 34127, Trieste, Italy.
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32
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Rani P, Mahato NK, Sharma A, Rao DLN, Kamra K, Lal R. Genome Mining and Predictive Functional Profiling of Acidophilic Rhizobacterium Pseudomonas fluorescens Pt14. Indian J Microbiol 2017; 57:155-161. [PMID: 28611492 DOI: 10.1007/s12088-017-0648-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2017] [Accepted: 04/05/2017] [Indexed: 12/01/2022] Open
Abstract
Pseudomonas fluorescens Pt14 is a non-pathogenic and acidophilic bacterium isolated from acidic soil (pH 4.65). Genome sequencing of strain Pt14 was performed using Single Molecule Real Time (SMRT) sequencing to get insights into unique existence of this strain in acidic environment. Complete genome sequence of this strain revealed a chromosome of 5,841,722 bp having 5354 CDSs and 88 RNAs. Phylogenomic reconstruction based on 16S rRNA gene, Average Nucleotide Identity (ANI) values and marker proteins revealed that strain Pt14 shared a common clade with P. fluorescens strain A506 and strain SS101. ANI value of strain Pt14 in relation to strain A506 was found 99.23% demonstrating a very close sub-species association at genome level. Further, orthology determination among these three phylogenetic neighbors revealed 4726 core proteins. Functional analysis elucidated significantly higher abundance of sulphur metabolism (>1×) which could be one of the reasons for the survival of strain Pt14 under acidic conditions (pH 4.65). Acidophilic bacteria have capability to oxidize sulphur into sulphuric acid which in turn can make the soil acidic and genome-wide analysis of P. fluorescens Pt14 demonstrated that this strain contributes towards making the soil acidic.
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Affiliation(s)
- Pooja Rani
- Molecular Biology Laboratory, Department of Zoology, University of Delhi, Delhi, 110007 India
| | - Nitish Kumar Mahato
- Molecular Biology Laboratory, Department of Zoology, University of Delhi, Delhi, 110007 India
| | - Anukriti Sharma
- Molecular Biology Laboratory, Department of Zoology, University of Delhi, Delhi, 110007 India
| | - Desiraju Lakshmi Narsimha Rao
- All India Network Project on Soil Biodiversity and Biofertilizers, Indian Institute of Soil Science, Bhopal, 462038 India
| | - Komal Kamra
- Ciliate Biology Laboratory, SGTB Khalsa College, University of Delhi, Delhi, 110007 India
| | - Rup Lal
- Molecular Biology Laboratory, Department of Zoology, University of Delhi, Delhi, 110007 India
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Bahl CD, St. Laurent JD, Karthikeyan RSG, Priya JL, Prajna L, Zegans ME, Madden DR. The cif Virulence Factor Gene Is Present in Isolates From Patients With Pseudomonas aeruginosa Keratitis. Cornea 2017; 36:358-362. [PMID: 28079684 PMCID: PMC5290206 DOI: 10.1097/ico.0000000000001132] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
PURPOSE To determine whether the cif gene is present in pathogenic Pseudomonas aeruginosa isolates from patients with bacterial keratitis at Aravind Eye Hospital, a referral eye care center in southern India, and from corresponding environmental isolates. METHODS Polymerase chain reaction amplification was performed on strains of P. aeruginosa isolated from ocular infections and environmental soil samples were collected from the area surrounding Aravind Eye Hospital. DNA sequencing of 16S ribosomal DNA amplicons was performed to verify strain identity. RESULTS We determined that 45 of 48 patient isolates carry a genomic copy of cif. Analysis of a catalog of environmental strains previously isolated from the surrounding area revealed that only 4 of 10 P. aeruginosa strains and 1 of 14 strains of related species carry the cif gene. CONCLUSIONS This is the first study to show that P. aeruginosa strains with ocular pathogenicity carry the cif gene and that the presence of this gene may be enriched over its prevalence in the environment. Taken together, these results suggest a potential role for Cif in acute bacterial keratitis.
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Affiliation(s)
- Christopher D. Bahl
- Department of Biochemistry & Cell Biology, Geisel School of
Medicine at Dartmouth, Hanover, NH, USA
| | - Jessica D. St. Laurent
- Department of Biochemistry & Cell Biology, Geisel School of
Medicine at Dartmouth, Hanover, NH, USA
| | - R. Siva Ganesa Karthikeyan
- Department of Ocular Microbiology, Dr G. Venkatasamy Eye Research
Institute, Aravind Medical Research Foundation, Madurai, Tamil Nadu, India
| | - J. Lakshmi Priya
- Department of Ocular Microbiology, Dr G. Venkatasamy Eye Research
Institute, Aravind Medical Research Foundation, Madurai, Tamil Nadu, India
| | - Lalitha Prajna
- Department of Ocular Microbiology, Dr G. Venkatasamy Eye Research
Institute, Aravind Medical Research Foundation, Madurai, Tamil Nadu, India
| | - Michael E. Zegans
- Department of Surgery (Ophthalmology), Geisel School of Medicine at
Dartmouth, Hanover, NH, USA
- Department of Microbiology & Immunology, Geisel School of
Medicine at Dartmouth, Hanover, NH, USA
| | - Dean R. Madden
- Department of Biochemistry & Cell Biology, Geisel School of
Medicine at Dartmouth, Hanover, NH, USA
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Rossi Gonçalves I, Dantas RCC, Ferreira ML, Batistão DWDF, Gontijo-Filho PP, Ribas RM. Carbapenem-resistant Pseudomonas aeruginosa: association with virulence genes and biofilm formation. Braz J Microbiol 2016; 48:211-217. [PMID: 28034598 PMCID: PMC5470431 DOI: 10.1016/j.bjm.2016.11.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2015] [Accepted: 04/25/2016] [Indexed: 11/30/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen that causes frequently nosocomial infections, currently becoming more difficult to treat due to the various resistance mechanisms and different virulence factors. The purpose of this study was to determine the risk factors independently associated with the development of bacteremia by carbapenem-resistant P. aeruginosa, the frequency of virulence genes in metallo-β-lactamases producers and to evaluate their ability to produce biofilm. We conducted a case–control study in the Uberlândia Federal University – Hospital Clinic, Brazil. Polymerase Chain Reaction was performed for metallo-β-lactamases and virulence genes. Adhesion and biofilm assays were done by quantitative tests. Among the 157 strains analyzed, 73.9% were multidrug-resistant, 43.9% were resistant to carbapenems, 16.1% were phenotypically positive for metallo-β-lactamases, and of these, 10.7% were positive for blaSPM gene and 5.3% positive for blaVIM. The multivariable analysis showed that mechanical ventilation, enteral/nasogastric tubes, primary bacteremia with unknown focus, and inappropriate therapy were independent risk factors associated with bacteremia. All tested strains were characterized as strongly biofilm producers. A higher mortality was found among patients with bacteremia by carbapenem-resistant P. aeruginosa strains, associated independently with extrinsic risk factors, however it was not evident the association with the presence of virulence and metallo-β-lactamases genes.
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Affiliation(s)
- Iara Rossi Gonçalves
- Universidade Federal de Uberlândia, Instituto de Ciências Biomédicas, Laboratório de Microbiologia, Uberlândia, MG, Brazil.
| | | | - Melina Lorraine Ferreira
- Universidade Federal de Uberlândia, Instituto de Ciências Biomédicas, Laboratório de Microbiologia, Uberlândia, MG, Brazil
| | | | - Paulo Pinto Gontijo-Filho
- Universidade Federal de Uberlândia, Instituto de Ciências Biomédicas, Laboratório de Microbiologia, Uberlândia, MG, Brazil
| | - Rosineide Marques Ribas
- Universidade Federal de Uberlândia, Instituto de Ciências Biomédicas, Laboratório de Microbiologia, Uberlândia, MG, Brazil
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35
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Pinnock A, Shivshetty N, Roy S, Rimmer S, Douglas I, MacNeil S, Garg P. Ex vivo rabbit and human corneas as models for bacterial and fungal keratitis. Graefes Arch Clin Exp Ophthalmol 2016; 255:333-342. [PMID: 27844206 PMCID: PMC5285415 DOI: 10.1007/s00417-016-3546-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Revised: 10/23/2016] [Accepted: 10/31/2016] [Indexed: 11/25/2022] Open
Abstract
PURPOSE In the study of microbial keratitis, in vivo animal models often require a large number of animals, and in vitro monolayer cell culture does not maintain the three-dimensional structure of the tissues or cell-to-cell communication of in vivo models. Here, we propose reproducible ex vivo models of single- and dual-infection keratitis as an alternative to in vivo and in vitro models. METHODS Excised rabbit and human corneoscleral rims maintained in organ culture were infected using 108 cells of Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans or Fusarium solani. The infection was introduced by wounding with a scalpel and exposing corneas to the microbial suspension or by intrastromal injection. Post-inoculation, corneas were maintained for 24 and 48 h at 37 °C. After incubation, corneas were either homogenised to determine colony-forming units (CFU)/cornea or processed for histological examination using routine staining methods. Single- and mixed-species infections were compared. RESULTS We observed a significant increase in CFU after 48 h compared to 24 h with S. aureus and P. aeruginosa. However, no such increase was observed in corneas infected with C. albicans or F. solani. The injection method yielded an approximately two- to 100-fold increase (p < 0.05) in the majority of organisms from infected corneas. Histology of the scalpel-wounded and injection models indicated extensive infiltration of P. aeruginosa throughout the entire cornea, with less infiltration observed for S. aureus, C. albicans and F. solani. The models also supported dual infections. CONCLUSIONS Both scalpel wounding and injection methods are suitable for inducing infection of ex vivo rabbit and human cornea models. These simple and reproducible models will be useful as an alternative to in vitro and in vivo models for investigating the detection and treatment of microbial keratitis, particularly when this might be due to two infective organisms.
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Affiliation(s)
| | | | - Sanhita Roy
- LV Prasad Eye Institute, Banjara Hills, Hyderabad, 500034, India
| | | | - Ian Douglas
- University of Sheffield, Sheffield, S10 2TA, UK
| | - Sheila MacNeil
- University of Sheffield, Sheffield, S10 2TA, UK.
- The Kroto Research Institute, North Campus, University of Sheffield, Broad Lane, Sheffield, S3 7HQ, UK.
| | - Prashant Garg
- LV Prasad Eye Institute, Banjara Hills, Hyderabad, 500034, India
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Hassuna NA. Molecular Detection of the Virulent ExoU Genotype of Pseudomonas aeruginosa Isolated from Infected Surgical Incisions. Surg Infect (Larchmt) 2016; 17:610-4. [PMID: 27441791 DOI: 10.1089/sur.2016.065] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Pseudomonas aeruginosa is one of the major pathogens responsible for hospital-acquired infections, which harbor a wide array of virulence factors. The main aim of this study was to determine the frequency of the virulent ExoU genotype in relation to the ExoS genotype among isolated P. aeruginosa from infected surgical incisions, followed by phylogenetic analysis. METHODS A total of 66 P. aeruginosa isolates were identified by cultural and biochemical characteristics. All isolates were tested for antimicrobial susceptibility against the following antimicrobial agents: imipenem, amikacin, gentamicin, amoxycillin, cefotaxime, cefepime, and levofloxacin. Molecular detection of the ExoS and ExoU as well as two other virulence genes was done by polymerase chain reaction (PCR). Sequencing of ExoU gene and phylogenetic analysis was performed. RESULTS Approximately 81% of the isolated P. aeruginosa were multi-drug resistant. The ExoS genotype was more prevalent (63%) among the isolates than the ExoU genotype (18%), with 9% of the isolates possessing both toxins. LasB and AprA were detected in 63.6% and 27.2% of the isolates, respectively. An association was observed between the number of virulence genes and the presence of multi-drug resistance. All the ExoU were multi-drug resistant (MDR), whereas 71% of the ExoS were MDR. Phylogenetic analysis of ExoU gene showed a 99% similarity with four different strains. CONCLUSION Despite the greater frequency of the ExoS genotype, the presence of the virulent MDR ExoU genotype isolates from surgical site infections is an alarming sign requiring further intervention and investigations.
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Affiliation(s)
- Noha A Hassuna
- Department of Microbiology and Immunology, Minia University , Minia, Egypt
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Soumpasis I, Knapp L, Pitt T. A proof-of-concept model for the identification of the key events in the infection process with specific reference to Pseudomonas aeruginosa in corneal infections. Infect Ecol Epidemiol 2015; 5:28750. [PMID: 26546946 PMCID: PMC4636861 DOI: 10.3402/iee.v5.28750] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 10/16/2015] [Accepted: 10/16/2015] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND It is a common medical practice to characterise an infection based on the causative agent and to adopt therapeutic and prevention strategies targeting the agent itself. However, from an epidemiological perspective, exposure to a microbe can be harmless to a host as a result of low-level exposure or due to host immune response, with opportunistic infection only occurring as a result of changes in the host, pathogen, or surrounding environment. METHODS We have attempted to review systematically the key host, pathogen, and environmental factors that may significantly impact clinical outcomes of exposure to a pathogen, using Pseudomonas aeruginosa eye infection as a case study. RESULTS AND DISCUSSION Extended contact lens wearing and compromised hygiene may predispose users to microbial keratitis, which can be a severe and vision-threatening infection. P. aeruginosa has a wide array of virulence-associated genes and sensing systems to initiate and maintain cell populations at the corneal surface and beyond. We have adapted the well-known concept of the epidemiological triangle in combination with the classic risk assessment framework (hazard identification, characterisation, and exposure) to develop a conceptual pathway-based model that demonstrates the overlapping relationships between the host, the pathogen, and the environment; and to illustrate the key events in P. aeruginosa eye infection. CONCLUSION This strategy differs from traditional approaches that consider potential risk factors in isolation, and hopefully will aid the identification of data and models to inform preventive and therapeutic measures in addition to risk assessment. Furthermore, this may facilitate the identification of knowledge gaps to direct research in areas of greatest impact to avert or mitigate adverse outcomes of infection.
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Affiliation(s)
- Ilias Soumpasis
- Safety and Environmental Assurance Centre, Unilever, Sharnbrook, UK;
| | - Laura Knapp
- Safety and Environmental Assurance Centre, Unilever, Sharnbrook, UK
| | - Tyrone Pitt
- Clinical Bacteriology Consultant, London, UK
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Sabharwal N, Dhall S, Chhibber S, Harjai K. Molecular detection of virulence genes as markers in Pseudomonas aeruginosa isolated from urinary tract infections. INTERNATIONAL JOURNAL OF MOLECULAR EPIDEMIOLOGY AND GENETICS 2014; 5:125-134. [PMID: 25379131 PMCID: PMC4214259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 07/19/2014] [Accepted: 09/10/2014] [Indexed: 06/04/2023]
Abstract
Catheter associated urinary tract infections by P. aeruginosa are related to variety of complications. Quorum sensing and related circuitry guard its virulence potential. Though P. aeruginosa accounts for an appreciable amount of virulence factors, this organism is highly unstable phenotypically. Thus, genotyping of clinical isolates of P. aeruginosa is of utmost importance for understanding the epidemiology of infection. This may contribute towards development of immunotherapeutic approaches against this multi drug resistant pathogen. Moreover, no epidemiological study has been reported yet on uroisolates of P. aeruginosa. Thus this study was planned to obtain information regarding presence, distribution and rate of occurrence of quorum sensing and some associated virulence genes at genetic level. The profiling of quorum sensing genes lasI, lasR, rhlI, rhlR and virulence genes like toxA, aprA, rhlAB, plcH, lasB and fliC of twelve strains of P. aeruginosa isolated from patients with UTIs was done by direct PCR. The results showed variable distribution of quorum sensing genes and virulence genes. Their percentage occurrence may be specifically associated with different levels of intrinsic virulence and pathogenicity in urinary tract. Such information can help in identifying these virulence genes as useful diagnostic markers for clinical P. aeruginosa strains isolated from UTIs.
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Affiliation(s)
- Neha Sabharwal
- Department of Microbiology, Basic Medical Sciences Block-I, South Campus, Panjab University Chandigarh, India, 160014
| | - Shriya Dhall
- Department of Microbiology, Basic Medical Sciences Block-I, South Campus, Panjab University Chandigarh, India, 160014
| | - Sanjay Chhibber
- Department of Microbiology, Basic Medical Sciences Block-I, South Campus, Panjab University Chandigarh, India, 160014
| | - Kusum Harjai
- Department of Microbiology, Basic Medical Sciences Block-I, South Campus, Panjab University Chandigarh, India, 160014
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Fazeli N, Momtaz H. Virulence Gene Profiles of Multidrug-Resistant Pseudomonas aeruginosa Isolated From Iranian Hospital Infections. IRANIAN RED CRESCENT MEDICAL JOURNAL 2014; 16:e15722. [PMID: 25763199 PMCID: PMC4329751 DOI: 10.5812/ircmj.15722] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Revised: 12/25/2013] [Accepted: 01/18/2014] [Indexed: 12/20/2022]
Abstract
Background: The most common hospital-acquired pathogen is Pseudomonas aeruginosa. It is a multidrug resistant bacterium causing systemic infections. Objectives: The present study was carried out in order to investigate the distribution of virulence factors and antibiotic resistance properties of Pseudomonas aeruginosa isolated from various types of hospital infections in Iran. Patients and Methods: Two-hundred and seventeen human infection specimens were collected from Baqiyatallah and Payambaran hospitals in Tehran, Iran. The clinical samples were cultured immediately and samples positive for P. aeruginosa were analyzed for the presence of antibiotic resistance and bacterial virulence genes using PCR (polymerase chain reaction). Antimicrobial susceptibility testing was performed using disk diffusion methodology with Müeller–Hinton agar. Results: Fifty-eight out of 127 (45.66%) male infection specimens and 44 out of 90 (48.88%) female infection specimens harbored P. aeruginosa. Also, 65% (in male specimens) and 21% (in female specimens) of respiratory system infections were positive for P. aeruginosa, which was a high rate. The genes encoding exoenzyme S (67.64%) and phospholipases C (45.09%) were the most common virulence genes found among the strains. The incidences of various β-lactams encoding genes, including blaTEM, blaSHV, blaOXA, blaCTX-M, blaDHA, and blaVEB were 94.11%, 16.66%, 15.68%, 18.62%, 21.56%, and 17.64%, respectively. The most commonly detected fluoroquinolones encoding gene was gyrA (15. 68%). High resistance levels to penicillin (100%), tetracycline (90.19%), streptomycin (64.70%), and erythromycin (43.13%) were observed too. Conclusions: Our findings should raise awareness about antibiotic resistance in hospitalized patients in Iran. Clinicians should exercise caution in prescribing antibiotics, especially in cases of human infections.
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Affiliation(s)
- Nastaran Fazeli
- Department of Microbiology, Shahrekord Branch, Islamic Azad University, Shahrekord, IR Iran
| | - Hassan Momtaz
- Department of Microbiology, Shahrekord Branch, Islamic Azad University, Shahrekord, IR Iran
- Corresponding Author: Hassan Momtaz, Department of Microbiology, Shahrekord Branch, Islamic Azad University, Shahrekord, IR Iran. Tel: +98-9133812574, E-mail:
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Zhang J, Chu Y, Wang P, Ji X, Li X, Wang C, Peng Y. Clinical Outcomes of Multidrug Resistant Pseudomonas aeruginosa Infection and the Relationship With Type III Secretion System in Patients With Diabetic Foot. INT J LOW EXTR WOUND 2014; 13:205-10. [DOI: 10.1177/1534734614545878] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The objective was to analyze the clinical outcomes of multidrug resistant Pseudomonas aeruginosa (MDRPA) infection and determine the relationship between type III secretion system (TTSS) and MDRPA in diabetic foot (DF) patients. A total of 117 patients infected with P aeruginosa were recruited and grouped into MDRPA and non-MDRPA group according to antimicrobial susceptibility testing. TTSS genes were detected by polymerase chain reaction (PCR). Potential risk factors for MDRPA infection were examined using univariate and multivariate analyses. Clinical outcomes were compared on the basis of MDRPA or TTSS virulence gene. Previous antibiotic therapy, previous hospitalization and osteomyelitis were associated with MDRPA infection. MDRPA group had a higher amputation/toe rate (32.6% vs 16.2%) and lower healing rate (20.9% vs 41.9%) than non-MDRPA group ( P = .032). A significantly higher proportion of exoU was present in MDRPA group (75.0% vs 25.0%, P < .05) than non-MDRPA group. Patients infected with exoU isolates had a lower healing rate and higher amputation/toe rate (25.0% vs 65.2%, 33.3% vs 8.7%, P < .05) than infected with exoS isolates. The exoU gene was predominance among MDRPA strains. The poor clinical outcomes of MDRPA infection in patients with DF were attributable to exoU gene.
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Affiliation(s)
- Jinghang Zhang
- 2011 Collaborative Innovation Center of Tianjin for Medical Epigenetics, The Key Laboratory of Hormones and Development(Ministry of Health), Department of Diabetic foot, the Metabolic Disease Hospital,Tianjin Institute of Endocrinology,Tianjin Medical University, Tianjin, China
| | - Yuejie Chu
- 2011 Collaborative Innovation Center of Tianjin for Medical Epigenetics, The Key Laboratory of Hormones and Development(Ministry of Health), Department of Diabetic foot, the Metabolic Disease Hospital,Tianjin Institute of Endocrinology,Tianjin Medical University, Tianjin, China
| | - Penghua Wang
- 2011 Collaborative Innovation Center of Tianjin for Medical Epigenetics, The Key Laboratory of Hormones and Development(Ministry of Health), Department of Diabetic foot, the Metabolic Disease Hospital,Tianjin Institute of Endocrinology,Tianjin Medical University, Tianjin, China
| | - Xiaoyan Ji
- 2011 Collaborative Innovation Center of Tianjin for Medical Epigenetics, The Key Laboratory of Hormones and Development(Ministry of Health), Department of Diabetic foot, the Metabolic Disease Hospital,Tianjin Institute of Endocrinology,Tianjin Medical University, Tianjin, China
| | - Xiwen Li
- 2011 Collaborative Innovation Center of Tianjin for Medical Epigenetics, The Key Laboratory of Hormones and Development(Ministry of Health), Department of Diabetic foot, the Metabolic Disease Hospital,Tianjin Institute of Endocrinology,Tianjin Medical University, Tianjin, China
| | - Chao Wang
- 2011 Collaborative Innovation Center of Tianjin for Medical Epigenetics, The Key Laboratory of Hormones and Development(Ministry of Health), Department of Diabetic foot, the Metabolic Disease Hospital,Tianjin Institute of Endocrinology,Tianjin Medical University, Tianjin, China
| | - Yue Peng
- 2011 Collaborative Innovation Center of Tianjin for Medical Epigenetics, The Key Laboratory of Hormones and Development(Ministry of Health), Department of Diabetic foot, the Metabolic Disease Hospital,Tianjin Institute of Endocrinology,Tianjin Medical University, Tianjin, China
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Tajima K, Miyake T, Koike N, Hattori T, Kumakura S, Yamaguchi T, Matsumoto T, Fujita K, Kuroda M, Ito N, Goto H. In vivo challenging of polymyxins and levofloxacin eye drop against multidrug-resistant Pseudomonas aeruginosa keratitis. J Infect Chemother 2014; 20:343-9. [DOI: 10.1016/j.jiac.2013.10.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Revised: 10/28/2013] [Accepted: 10/29/2013] [Indexed: 11/25/2022]
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Cytotoxic clinical isolates of Pseudomonas aeruginosa identified during the Steroids for Corneal Ulcers Trial show elevated resistance to fluoroquinolones. BMC Ophthalmol 2014; 14:54. [PMID: 24761794 PMCID: PMC4008435 DOI: 10.1186/1471-2415-14-54] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 04/11/2014] [Indexed: 12/18/2022] Open
Abstract
Background To determine the relationship between type three secretion genotype and fluoroquinolone resistance for P. aeruginosa strains isolated from microbial keratitis during the Steroids for Corneal Ulcers Trial (SCUT) and for two laboratory strains, PA103 and PAO1. Methods Confirmed P. aeruginosa isolates from the SCUT were divided into exoU(+) or exoU(−). The exoU(+) strains contained the gene encoding ExoU, a powerful phospholipase toxin delivered into host cells by the type three secretion system. Isolates were then assessed for susceptibility to fluoroquinolone, cephalosporin, and aminoglycoside antibiotics using disk diffusion assays. Etest was used to determine the MIC of moxifloxacin and other fluoroquinolones. Laboratory isolates in which the exoU gene was added or deleted were also tested. Results A significantly higher proportion of exoU(+) strains were resistant to ciprofloxacin (p = 0.001), gatifloxacin (p = 0.003), and ofloxacin (p = 0.002) compared to exoU(−) isolates. There was no significant difference between exoU(+) or exoU(−) negative isolates with respect to susceptibility to other antibiotics except gentamicin. Infections involving resistant exoU(+) strains trended towards worse clinical outcome. Deletion or acquisition of exoU in laboratory isolates did not affect fluoroquinolone susceptibility. Conclusions Fluoroquinolone susceptibility of P. aeruginosa isolated from the SCUT is consistent with previous studies showing elevated resistance involving exoU encoding (cytotoxic) strains, and suggest worse clinical outcome from infections involving resistant isolates. Determination of exoU expression in clinical isolates of P. aeruginosa may be helpful in directing clinical management of patients with microbial keratitis.
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Yamaguchi S, Suzuki T, Kobayashi T, Oka N, Ishikawa E, Shinomiya H, Ohashi Y. Genotypic analysis of Pseudomonas aeruginosa isolated from ocular infection. J Infect Chemother 2014; 20:407-11. [PMID: 24746897 DOI: 10.1016/j.jiac.2014.02.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 02/06/2014] [Accepted: 02/27/2014] [Indexed: 11/18/2022]
Abstract
Pseudomonas aeruginosa is the causative pathogen of keratitis, conjunctivitis, and dacryocystitis. However little is known about their clinical epidemiology in Japan. In this study we investigated the genotypic characterization and serotype of P. aeruginosa isolates from ocular infections. Thirty-four clinical P. aeruginosa isolates were characterized according to infection type, the type III secretion system (TTSS), serotype, and multilocus sequence typing (MLST). We divided the isolates into four clinical infection types as follows: Contact lens (CL)-related keratitis (CL-keratitis; 15 isolates), non CL-related keratitis (non CL-keratitis; 8 isolates), conjunctivitis (7 isolates), and dacryocystitis (4 isolates). Regarding the TTSS classification and serotyping classification, no significant differences were found among the infection types. Two clusters (I, II) and three subclusters (A, B, C) were classified according to MLST. CL-keratitis isolates with exoU positivity were clustered in II-B, and conjunctivitis was clustered in cluster I. Some linkage was found between the genetic background and CL-keratitis or conjunctivitis.
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Affiliation(s)
- Satoshi Yamaguchi
- Department of Ophthalmology, Ehime University, Graduate School of Medicine, Shitsukawa, Toon, Ehime 791-0295, Japan; ROHTO Pharmaceutical Co., Ltd., 1-8-1 Tatsumi-nishi, Ikuno-ku, Osaka 544-8666, Japan
| | - Takashi Suzuki
- Department of Ophthalmology, Ehime University, Graduate School of Medicine, Shitsukawa, Toon, Ehime 791-0295, Japan.
| | - Takeshi Kobayashi
- Department of Ophthalmology, Ehime University, Graduate School of Medicine, Shitsukawa, Toon, Ehime 791-0295, Japan
| | - Naoko Oka
- Department of Ophthalmology, Ehime University, Graduate School of Medicine, Shitsukawa, Toon, Ehime 791-0295, Japan
| | - Eri Ishikawa
- Department of Ophthalmology, Ehime University, Graduate School of Medicine, Shitsukawa, Toon, Ehime 791-0295, Japan
| | - Hiroto Shinomiya
- Ehime Prefectural Institute of Public Health And Environmental Science, 8-234 Sanbancho, Matsuyama, Ehime 790-0003, Japan
| | - Yuichi Ohashi
- Department of Ophthalmology, Ehime University, Graduate School of Medicine, Shitsukawa, Toon, Ehime 791-0295, Japan
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Ceremuga I, Seweryn E, Bednarz-Misa I, Pietkiewicz J, Jermakow K, Banaś T, Gamian A. Enolase-like protein present on the outer membrane of Pseudomonas aeruginosa binds plasminogen. Folia Microbiol (Praha) 2014; 59:391-7. [PMID: 24671511 PMCID: PMC4133640 DOI: 10.1007/s12223-014-0311-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Accepted: 02/18/2014] [Indexed: 11/27/2022]
Abstract
Pseudomonas aeruginosa is one of the pathogenic bacteria which utilize binding of the host plasminogen (Plg) to promote their invasion throughout the host tissues. In the present study, we confirmed that P. aeruginosa exhibits binding affinity for human plasminogen. Furthermore, we showed that the protein detected on the cell wall of P. aeruginosa and binding human plasminogen is an enolase-like protein. The hypothesis that alpha-enolase, a cytoplasmatic glycolytic enzyme, resides also on the cell surface of the bacterium was supported by electron microscopy analysis. The plasminogen-binding activity of bacterial cell wall outer membrane enolase-like protein was examined by immunoblotting assay.
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Affiliation(s)
- Ireneusz Ceremuga
- Department of Medical Biochemistry, Wroclaw Medical University, Chalubinskiego 10, 50-368, Wroclaw, Poland,
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Pereira SG, Rosa AC, Ferreira AS, Moreira LM, Proença DN, Morais PV, Cardoso O. Virulence factors and infection ability of Pseudomonas aeruginosa isolates from a hydropathic facility and respiratory infections. J Appl Microbiol 2014; 116:1359-68. [PMID: 24484457 DOI: 10.1111/jam.12463] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 01/17/2014] [Accepted: 01/27/2014] [Indexed: 11/27/2022]
Abstract
AIMS To compare the virulence pool and acute infection ability of Pseudomonas aeruginosa isolates from a hydropathic facility, used to treat respiratory conditions by inhalation of untreated natural mineral water, with clinical isolates from respiratory infections. METHODS AND RESULTS Pseudomonas aeruginosa isolates from a hydropathic facility and from respiratory infections were typed by pulsed-field gel electrophoresis. Nonclonal representatives of each population were selected. 18 virulence-encoding genes were screened by polymerase chain reaction and statistically compared by multiple correspondence analysis. Homogeneous distribution of genes between populations but higher genetic association in aquatic isolates was observed, as well as distinct virulence pool according to location in the water system. Acute infection ability of selected isolates from each population, in Galleria mellonella model, showed lower LD50 of the majority of the hydropathic isolates and significant variations in LD50 of biofilm isolates from different equipments. CONCLUSIONS Hydrotherapy Ps. aeruginosa isolates present similar virulence to isolates from respiratory infections. Hydrotherapy users may be exposed to different microbiological risks when using different treatment equipments. SIGNIFICANCE AND IMPACT OF THE STUDY Twenty-one million people use hydropathic facilities in Europe, and the majority present risk factors to pneumonia. This study demonstrates the health risk associated with this practice. Revision of European regulations should be considered.
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Affiliation(s)
- S G Pereira
- Center for Pharmaceutical Studies, Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
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Toska J, Sun Y, Carbonell DA, Foster ANS, Jacobs MR, Pearlman E, Rietsch A. Diversity of virulence phenotypes among type III secretion negative Pseudomonas aeruginosa clinical isolates. PLoS One 2014; 9:e86829. [PMID: 24466261 PMCID: PMC3900666 DOI: 10.1371/journal.pone.0086829] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Accepted: 12/14/2013] [Indexed: 11/18/2022] Open
Abstract
Pseudomonas aeruginosa is a frequent cause of acute infections. The primary virulence factor that has been linked to clinical disease is the type III secretion system, a molecular syringe that delivers effector proteins directly into host cells. Despite the importance of type III secretion in dictating clinical outcomes and promoting disease in animal models of infections, clinical isolates often do not express the type III secretion system in vitro. Here we screened 81 clinical P. aeruginosa isolates for secretion of type III secretion system substrates by western blot. Non-expressing strains were also subjected to a functional test assaying the ability to intoxicate epithelial cells in vitro, and to survive and cause disease in a murine model of corneal infection. 26 of 81 clinical isolates were found to be type III secretion negative by western blot. 17 of these 26 non-expressing strains were tested for their ability to cause epithelial cell rounding. Of these, three isolates caused epithelial cell rounding in a type III secretion system dependent manner, and one strain was cytotoxic in a T3SS-independent manner. Five T3SS-negative isolates were also tested for their ability to cause disease in a murine model of corneal infection. Of these isolates, two strains caused severe corneal disease in a T3SS-independent manner. Interestingly, one of these strains caused significant disease (inflammation) despite being cleared. Our data therefore show that P. aeruginosa clinical isolates can cause disease in a T3SS-independent manner, demonstrating the existence of novel modifiers of clinical disease.
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Affiliation(s)
- Jonida Toska
- Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Yan Sun
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Dalina Alvarez Carbonell
- Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Altreisha N. -S. Foster
- Department of Pathology, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
| | - Michael R. Jacobs
- Department of Pathology, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
| | - Eric Pearlman
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Arne Rietsch
- Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, Ohio, United States of America
- * E-mail:
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Bandiera A, Markulin A, Corich L, Vita F, Borelli V. Stimuli-Induced Release of Compounds from Elastin Biomimetic Matrix. Biomacromolecules 2013; 15:416-22. [DOI: 10.1021/bm401677n] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Antonella Bandiera
- Department
of Life Sciences, University of Trieste, 34127 Trieste, Italy
| | - Ana Markulin
- Department
of Life Sciences, University of Trieste, 34127 Trieste, Italy
| | - Lucia Corich
- Department
of Life Sciences, University of Trieste, 34127 Trieste, Italy
| | - Francesca Vita
- Department
of Life Sciences, University of Trieste, 34127 Trieste, Italy
| | - Violetta Borelli
- Department
of Life Sciences, University of Trieste, 34127 Trieste, Italy
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Pouring salt on a wound: Pseudomonas aeruginosa virulence factors alter Na+ and Cl- flux in the lung. J Bacteriol 2013; 195:4013-9. [PMID: 23836869 DOI: 10.1128/jb.00339-13] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Pseudomonas aeruginosa is a ubiquitous opportunistic pathogen with multiple niches in the human body, including the lung. P. aeruginosa infections are particularly damaging or fatal for patients with ventilator-associated pneumonia, chronic obstructive pulmonary disease, and cystic fibrosis (CF). To establish an infection, P. aeruginosa relies on a suite of virulence factors, including lipopolysaccharide, phospholipases, exoproteases, phenazines, outer membrane vesicles, type III secreted effectors, flagella, and pili. These factors not only damage the epithelial cell lining but also induce changes in cell physiology and function such as cell shape, membrane permeability, and protein synthesis. While such virulence factors are important in initial infection, many become dysregulated or nonfunctional during the course of chronic infection. Recent work on the virulence factors alkaline protease (AprA) and CF transmembrane conductance regulator inhibitory factor (Cif) show that P. aeruginosa also perturbs epithelial ion transport and osmosis, which may be important for the long-term survival of this microbe in the lung. Here we discuss the literature regarding host physiology-altering virulence factors with a focus on Cif and AprA and their potential roles in chronic infection and immune evasion.
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Petit SMC, Lavenir R, Colinon-Dupuich C, Boukerb AM, Cholley P, Bertrand X, Freney J, Doléans-Jordheim A, Nazaret S, Laurent F, Cournoyer B. Lagooning of wastewaters favors dissemination of clinically relevant Pseudomonas aeruginosa. Res Microbiol 2013; 164:856-66. [PMID: 23792168 DOI: 10.1016/j.resmic.2013.06.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Accepted: 06/02/2013] [Indexed: 12/01/2022]
Abstract
The significance of wastewater treatment lagoons (WWTLs) as point sources of clinically relevant Pseudomonas aeruginosa that can disseminate through rural and peri-urban catchments was investigated. A panel of P. aeruginosa strains collected over three years from WWTLs and community-acquired infections was compared by pulsed field gel electrophoresis (PFGE) DNA fingerprinting and multilocus sequence typing (MLST). Forty-four distantly related PFGE profiles and four clonal complexes were found among the WWTL strains analyzed. Some genotypes were repeatedly detected from different parts of WWTLs, including the influent, suggesting an ability to migrate and persist over time. MLST showed all investigated lineages to match sequence types described in other countries and strains from major clinical clones such as PA14 of ST253 and "C" of ST17 were observed. Some of these genotypes matched isolates from community-acquired infections recorded in the WWTL geographic area. Most WWTL strains harbored the main P. aeruginosa virulence genes; 13% harbored exoU-encoded cytoxins, but on at least six different genomic islands, with some of these showing signs of genomic instability. P. aeruginosa appeared to be highly successful opportunistic colonizers of WWTLs. Lagooning of wastewaters was found to favor dissemination of clinically relevant P. aeruginosa among peri-urban watersheds.
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Affiliation(s)
- Stéphanie M-C Petit
- Université de Lyon, Lyon, France; Research Group on Bacterial Opportunistic Pathogens and Environment, UMR5557 Ecologie Microbienne, Doua Campus, Université Lyon 1, CNRS, VetAgro Sup, 69622 Villeurbanne, France
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Borkar DS, Fleiszig SMJ, Leong C, Lalitha P, Srinivasan M, Ghanekar AA, Tam C, Li WY, Zegans ME, McLeod SD, Lietman TM, Acharya NR. Association between cytotoxic and invasive Pseudomonas aeruginosa and clinical outcomes in bacterial keratitis. JAMA Ophthalmol 2013; 131:147-53. [PMID: 23411878 DOI: 10.1001/jamaophthalmol.2013.778] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
OBJECTIVES To determine whether cytotoxic and invasive Pseudomonas aeruginosa strains differentially influence clinical presentation, outcomes, or therapeutic response in bacterial keratitis. METHODS Pseudomonas aeruginosa isolates from the National Eye Institute-funded Steroids for Corneal Ulcers Trial were subtyped as cytotoxic or invasive strains. The main outcome measure compared between the 2 subtypes was change in visual acuity at 3 months using Huber robust regression, adjusting for topical corticosteroid treatment. RESULTS Of 101 confirmed P aeruginosa isolates from the Steroids for Corneal Ulcers Trial, 74 had a classically cytotoxic or invasive genotype. While corneal ulcers caused by genotypically invasive P aeruginosa strains were associated at presentation with significantly better visual acuity than corneal ulcers caused by genotypically cytotoxic P aeruginosa strains when adjusting for the effect of ulcer location (P= .008), invasive ulcers had improved significantly less than cytotoxic ulcers at 3 months (0.35; 95% CI, 0.04-0.66 logMAR; P= .03 [3.5-line difference]). Compared with topical moxifloxacin alone, adjunctive treatment with topical corticosteroids was associated with significantly more improvement in visual acuity in the invasive subgroup (P= .04) but was associated with less improvement in visual acuity in the cytotoxic subgroup (P= .07). CONCLUSIONS Rational profiling of differentially expressed virulence determinants (eg, cytotoxicity and invasiveness for P aeruginosa) could be used as a tool for decision making in the management of infections to optimize outcomes.
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Affiliation(s)
- Durga S Borkar
- F. I. Proctor Foundation, University of California, San Francisco, San Francisco, CA 94143-0412, USA
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