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Zafer MM, Mohamed GA, Ibrahim SRM, Ghosh S, Bornman C, Elfaky MA. Biofilm-mediated infections by multidrug-resistant microbes: a comprehensive exploration and forward perspectives. Arch Microbiol 2024; 206:101. [PMID: 38353831 PMCID: PMC10867068 DOI: 10.1007/s00203-023-03826-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 12/30/2023] [Indexed: 02/16/2024]
Abstract
A biofilm is a collection of microorganisms organized in a matrix of extracellular polymeric material. Biofilms consist of microbial cells that attach to both surfaces and each other, whether they are living or non-living. These microbial biofilms can lead to hospital-acquired infections and are generally detrimental. They possess the ability to resist the human immune system and antibiotics. The National Institute of Health (NIH) states that biofilm formation is associated with 65% of all microbial illnesses and 80% of chronic illnesses. Additionally, non-device-related microbial biofilm infections include conditions like cystic fibrosis, otitis media, infective endocarditis, and chronic inflammatory disorders. This review aims to provide an overview of research on chronic infections caused by microbial biofilms, methods used for biofilm detection, recent approaches to combat biofilms, and future perspectives, including the development of innovative antimicrobial strategies such as antimicrobial peptides, bacteriophages, and agents that disrupt biofilms.
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Affiliation(s)
- Mai M Zafer
- Department of Microbiology and Immunology, Faculty of Pharmacy, Ahram Canadian University, Cairo, Egypt.
| | - Gamal A Mohamed
- Department of Natural Products and Alternative Medicine, Faculty of Pharmacy, King Abdulaziz University, 21589, Jeddah, Saudi Arabia
| | - Sabrin R M Ibrahim
- Department of Chemistry, Preparatory Year Program, Batterjee Medical College, 21442, Jeddah, Saudi Arabia
- Department of Pharmacognosy, Faculty of Pharmacy, Assiut University, Assiut, 71526, Egypt
| | - Soumya Ghosh
- Natural and Medical Science Research Center, University of Nizwa, Nizwa, 616, Oman
| | - Charné Bornman
- Department of Engineering Sciences, Faculty of Natural and Agricultural Sciences, University of the Free State, Bloemfontein, 9301, South Africa
| | - Mahmoud A Elfaky
- Department of Natural Products and Alternative Medicine, Faculty of Pharmacy, King Abdulaziz University, 21589, Jeddah, Saudi Arabia.
- Center for Artificial Intelligence in Precision Medicine, King Abdulaziz University, 21589, Jeddah, Saudi Arabia.
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Yang D, Zhao L, Li Q, Huang L, Qin Y, Wang P, Zhu C, Yan Q. The involvement of the T6SS vgrG gene in the pathogenicity of Pseudomonas plecoglossicida. JOURNAL OF FISH DISEASES 2023; 46:1097-1108. [PMID: 37401135 DOI: 10.1111/jfd.13829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 06/19/2023] [Accepted: 06/21/2023] [Indexed: 07/05/2023]
Abstract
Pseudomonas plecoglossicida, the causative agent of white spot disease of large yellow croaker, has caused serious economic losses to the aquaculture industry. The type VI secretion system (T6SS) is a significant virulence system widely distributed among Gram-negative bacteria. VgrG, a structural and core component of T6SS, is crucial to the function of T6SS. To explore the biological profiles mediated by vgrG gene and its effects on the pathogenicity of P. plecoglossicida, the vgrG gene deletion (ΔvgrG) strain and complementary (C-ΔvgrG) strain were constructed and the differences in pathogenicity and virulence-related characteristics between different strains were analysed. The results showed that vgrG gene deletion significantly affected the virulence-related characteristics of P. plecoglossicida, including chemotaxis, adhesion, and biofilm formation. In addition, the LD50 of ΔvgrG strain was nearly 50-fold higher than that of the NZBD9 strain. Transcriptome data analysis suggested that the vgrG gene may affect the virulence of P. plecoglossicida by regulating the quorum sensing pathway to inhibit the secretion of virulence factors and affect biofilm formation. Besides, deletion of the vgrG gene may reduce bacterial pathogenicity by affecting bacterial signal transduction processes and the ability to adapt to chemotactic substances.
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Affiliation(s)
- Dou Yang
- Fisheries College, Jimei University, Xiamen, China
| | - Lingmin Zhao
- Fisheries College, Jimei University, Xiamen, China
| | - Qi Li
- Fisheries College, Jimei University, Xiamen, China
| | - Lixing Huang
- Fisheries College, Jimei University, Xiamen, China
| | - Yingxue Qin
- Fisheries College, Jimei University, Xiamen, China
| | - Pan Wang
- Key Laboratory of Aquatic Functional Feed and Environmental Regulation of Fujian Province, Fujian Dabeinong Aquatic Sci. & Tech. Co., Ltd, Zhangzhou, China
| | - Chuanzhong Zhu
- Key Laboratory of Aquatic Functional Feed and Environmental Regulation of Fujian Province, Fujian Dabeinong Aquatic Sci. & Tech. Co., Ltd, Zhangzhou, China
| | - Qingpi Yan
- Fisheries College, Jimei University, Xiamen, China
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Gadar K, McCarthy RR. Using next generation antimicrobials to target the mechanisms of infection. NPJ ANTIMICROBIALS AND RESISTANCE 2023; 1:11. [PMID: 38686217 PMCID: PMC11057201 DOI: 10.1038/s44259-023-00011-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Accepted: 07/28/2023] [Indexed: 05/02/2024]
Abstract
The remarkable impact of antibiotics on human health is being eroded at an alarming rate by the emergence of multidrug resistant pathogens. There is a recognised consensus that new strategies to tackle infection are urgently needed to limit the devasting impact of antibiotic resistance on our global healthcare infrastructure. Next generation antimicrobials (NGAs) are compounds that target bacterial virulence factors to disrupt pathogenic potential without impacting bacterial viability. By disabling the key virulence factors required to establish and maintain infection, NGAs make pathogens more vulnerable to clearance by the immune system and can potentially render them more susceptible to traditional antibiotics. In this review, we discuss the developing field of NGAs and how advancements in this area could offer a viable standalone alternative to traditional antibiotics or an effective means to prolong antibiotic efficacy when used in combination.
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Affiliation(s)
- Kavita Gadar
- Division of Biosciences, Department of Life Sciences, College of Health, Medicine and Life Sciences, Brunel University London, Uxbridge, UB8 3PH United Kingdom
| | - Ronan R. McCarthy
- Division of Biosciences, Department of Life Sciences, College of Health, Medicine and Life Sciences, Brunel University London, Uxbridge, UB8 3PH United Kingdom
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Qiu Y, Chien CC, Maroulis B, Bei J, Gaitas A, Gong B. Extending applications of AFM to fluidic AFM in single living cell studies. J Cell Physiol 2022; 237:3222-3238. [PMID: 35696489 PMCID: PMC9378449 DOI: 10.1002/jcp.30809] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 05/25/2022] [Indexed: 12/30/2022]
Abstract
In this article, a review of a series of applications of atomic force microscopy (AFM) and fluidic Atomic Force Microscopy (fluidic AFM, hereafter fluidFM) in single-cell studies is presented. AFM applications involving single-cell and extracellular vesicle (EV) studies, colloidal force spectroscopy, and single-cell adhesion measurements are discussed. FluidFM is an offshoot of AFM that combines a microfluidic cantilever with AFM and has enabled the research community to conduct biological, pathological, and pharmacological studies on cells at the single-cell level in a liquid environment. In this review, capacities of fluidFM are discussed to illustrate (1) the speed with which sequential measurements of adhesion using coated colloid beads can be done, (2) the ability to assess lateral binding forces of endothelial or epithelial cells in a confluent cell monolayer in an appropriate physiological environment, and (3) the ease of measurement of vertical binding forces of intercellular adhesion between heterogeneous cells. Furthermore, key applications of fluidFM are reviewed regarding to EV absorption, manipulation of a single living cell by intracellular injection, sampling of cellular fluid from a single living cell, patch clamping, and mass measurements of a single living cell.
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Affiliation(s)
- Yuan Qiu
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Chen-Chi Chien
- The Estelle and Daniel Maggin Department of Neurology, Icahn School of Medicine at Mount Sinai, New York City, New York, USA
| | - Basile Maroulis
- The Estelle and Daniel Maggin Department of Neurology, Icahn School of Medicine at Mount Sinai, New York City, New York, USA
| | - Jiani Bei
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Angelo Gaitas
- The Estelle and Daniel Maggin Department of Neurology, Icahn School of Medicine at Mount Sinai, New York City, New York, USA.,BioMedical Engineering & Imaging Institute, Leon and Norma Hess Center for Science and Medicine, New York City, New York, USA
| | - Bin Gong
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA.,Sealy Center for Vector Borne and Zoonotic Diseases, University of Texas Medical Branch, Galveston, Texas, USA.,Center for Biodefense and Emerging Infectious Diseases, University of Texas Medical Branch, Galveston, Texas, USA.,Institute for Human Infectious and Immunity, University of Texas Medical Branch, Galveston, Texas, USA
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Birhanu BT, Park NH, Lee SJ, Hossain MA, Park SC. Inhibition of Salmonella Typhimurium adhesion, invasion, and intracellular survival via treatment with methyl gallate alone and in combination with marbofloxacin. Vet Res 2018; 49:101. [PMID: 30286813 PMCID: PMC6389159 DOI: 10.1186/s13567-018-0597-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 09/23/2018] [Indexed: 12/19/2022] Open
Abstract
Salmonella enterica serovar Typhimurium infects intestinal epithelia and macrophages, which is prevented by inhibiting adhesion and cell invasion. This study aimed to investigate the role of methyl gallate (MG) in adhesion, invasion, and intracellular survival of Salmonella Typhimurium in Caco-2 and RAW 264.7 cells via a gentamicin protection assay, confocal microscopy, and quantitative reverse-transcription polymerase chain reaction. MG (30 µg/mL) inhibited adhesion and invasion of Salmonella Typhimurium by 54.01% and 60.5% in RAW 264.7 cells, respectively. The combination of MG with sub-minimum inhibitory concentration (MIC) of marbofloxacin (MRB) inhibited the adhesion, invasion, and intracellular survival by 70.49%, 67.36%, and 74%, respectively. Confocal microscopy further revealed reductions in bacterial count in Caco-2 cells treated with MG alone or with sub-MIC of MRB. Furthermore, MG alone or in combination with sub-MIC of MRB decreased the motility of Salmonella Typhimurium. Quorum sensing genes including sdiA, srgE, and rck were downregulated by 52.8%, 61.7%, and 22.2%, respectively. Moreover, rac-1 was downregulated by 56.9% and 71.9% for MG alone and combined with sub-MIC of MRB, respectively, in mammalian cells. Furthermore, MG downregulated virulence genes of Salmonella Typhimurium including cheY, ompD, sipB, lexA, and ompF by 59.6%, 60.2%, 20.5%, 31.4%, and 16.2%, respectively. Together, the present results indicate that MG alone or in combination with a sub-MIC of MRB effectively inhibited the adhesion, invasion, and intracellular survival of Salmonella Typhimurium in vitro by downregulating quorum sensing and virulence genes.
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Affiliation(s)
- Biruk Tesfaye Birhanu
- Laboratory of Veterinary Pharmacokinetics and Pharmacodynamics, College of Veterinary Medicine, Kyungpook National University, Bukgu, Daegu, 41566, South Korea
| | - Na-Hye Park
- Laboratory of Veterinary Pharmacokinetics and Pharmacodynamics, College of Veterinary Medicine, Kyungpook National University, Bukgu, Daegu, 41566, South Korea
| | - Seung-Jin Lee
- Laboratory of Veterinary Pharmacokinetics and Pharmacodynamics, College of Veterinary Medicine, Kyungpook National University, Bukgu, Daegu, 41566, South Korea
| | - Md Akil Hossain
- Veterinary Drugs and Biologics Division, Animal and Plant Quarantine Agency, Gimcheon, 39660, South Korea
| | - Seung-Chun Park
- Laboratory of Veterinary Pharmacokinetics and Pharmacodynamics, College of Veterinary Medicine, Kyungpook National University, Bukgu, Daegu, 41566, South Korea.
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Li K, Wu KY, Wu W, Wang N, Zhang T, Choudhry N, Song Y, Farrar CA, Ma L, Wei LL, Duan ZY, Dong X, Liu EQ, Li ZF, Sacks SH, Zhou W. C5aR1 promotes acute pyelonephritis induced by uropathogenic E. coli. JCI Insight 2017; 2:97626. [PMID: 29263309 PMCID: PMC5752266 DOI: 10.1172/jci.insight.97626] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 11/21/2017] [Indexed: 02/01/2023] Open
Abstract
C5a receptor 1 (C5aR1) is a G protein-coupled receptor for C5a and also an N-linked glycosylated protein. In addition to myeloid cells, C5aR1 is expressed on epithelial cells. In this study, we examined the role of C5aR1 in bacterial adhesion/colonization of renal tubular epithelium and addressed the underlying mechanisms of this role. We show that acute kidney infection was significantly reduced in mice with genetic deletion or through pharmacologic inhibition of C5aR1 following bladder inoculation with uropathogenic E. coli (UPEC). This was associated with reduced expression of terminal α-mannosyl residues (Man; a ligand for type 1 fimbriae of E. coli) on the luminal surface of renal tubular epithelium and reduction of early UPEC colonization in these mice. Confocal microscopy demonstrated that UPEC bind to Man on the luminal surface of renal tubular epithelium. In vitro analyses showed that C5a stimulation enhances Man expression in renal tubular epithelial cells and subsequent bacterial adhesion, which, at least in part, is dependent on TNF-α driven by C5aR1-mediated intracellular signaling. Our findings demonstrate a previously unknown pathogenic role for C5aR1 in acute pyelonephritis, proposing a potentially novel mechanism by which C5a/C5aR1 signaling mediates upregulation of carbohydrate ligands on renal tubules to facilitate UPEC adhesion.
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Affiliation(s)
- Ke Li
- Core Research Laboratory, The Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, China
| | - Kun-Yi Wu
- Core Research Laboratory, The Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, China
| | - Weiju Wu
- Medical Research Council (MRC) Centre for Transplantation, King's College London, Guy's Hospital, United Kingdom (UK)
| | - Na Wang
- Core Research Laboratory, The Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, China
| | - Ting Zhang
- Core Research Laboratory, The Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, China
| | - Naheed Choudhry
- Medical Research Council (MRC) Centre for Transplantation, King's College London, Guy's Hospital, United Kingdom (UK)
| | - Yun Song
- Core Research Laboratory, The Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, China
| | - Conrad A Farrar
- Medical Research Council (MRC) Centre for Transplantation, King's College London, Guy's Hospital, United Kingdom (UK)
| | - Liang Ma
- Medical Research Council (MRC) Centre for Transplantation, King's College London, Guy's Hospital, United Kingdom (UK)
| | - Lin-Lin Wei
- Core Research Laboratory, The Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, China
| | - Zhao-Yang Duan
- Department of Nephrology, The Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, China
| | - Xia Dong
- Medical Research Council (MRC) Centre for Transplantation, King's College London, Guy's Hospital, United Kingdom (UK)
| | - En-Qi Liu
- Research Institute of Atherosclerotic Disease, School of Medicine, Xi'an Jiaotong University, Xi'an, China
| | - Zong-Fang Li
- National Local Joint Engineering Research Centre of Biodiagnostics and Biotherapy, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China
| | - Steven H Sacks
- Medical Research Council (MRC) Centre for Transplantation, King's College London, Guy's Hospital, United Kingdom (UK)
| | - Wuding Zhou
- Medical Research Council (MRC) Centre for Transplantation, King's College London, Guy's Hospital, United Kingdom (UK)
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Abstract
Protection of mucosal tissues of the oral cavity, intestines, respiratory tract, and urogenital tract from the constant challenge of pathogens is achieved by the combined barrier function of the lining epithelia and specialized immune cells. Recent studies have indicated that osteopontin (OPN) has a pivotal role in the development of immune responses and in the tissue destruction and the subsequent repair processes associated with inflammatory diseases. While expression of OPN is increased in immune cells—including neutrophils, macrophages, T- and B-lymphocytes—and in epithelial, endothelial, and fibroblastic cells of inflamed tissues, deciphering the specific functions of OPN has been difficult. In part, this is due to the broad range of biological activities of OPN that are mediated by multiple receptors which recognize several signaling motifs whose activities are influenced by post-translational modifications and proteolytic processing of OPN. Understanding the role of OPN in mucosal inflammation is further complicated by its contributions to the barrier function of the lining epithelia and the complexity of the specialized mucosal immune system. In an attempt to provide some insights into the involvement of OPN in mucosal diseases, this review summarizes current knowledge of the biological activities of OPN involved in the development of inflammatory responses and in wound healing, and indicates how these activities may affect the protection of mucosal tissues.
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Affiliation(s)
- J Sodek
- CIHR Group in Matrix Dynamics, Faculty of Dentistry, University of Toronto, ON, Canada
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Choudhry N, Li K, Zhang T, Wu KY, Song Y, Farrar CA, Wang N, Liu CF, Peng Q, Wu W, Sacks SH, Zhou W. The complement factor 5a receptor 1 has a pathogenic role in chronic inflammation and renal fibrosis in a murine model of chronic pyelonephritis. Kidney Int 2016; 90:540-54. [PMID: 27370410 PMCID: PMC4996631 DOI: 10.1016/j.kint.2016.04.023] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Revised: 04/12/2016] [Accepted: 04/28/2016] [Indexed: 02/07/2023]
Abstract
Complement factor 5a (C5a) interaction with its receptor (C5aR1) contributes to the pathogenesis of inflammatory diseases, including acute kidney injury. However, its role in chronic inflammation, particularly in pathogen-associated disorders, is largely unknown. Here we tested whether the development of chronic inflammation and renal fibrosis is dependent on C5aR1 in a murine model of chronic pyelonephritis. C5aR1-deficient (C5aR1-/-) mice showed a significant reduction in bacterial load, tubule injury and tubulointerstitial fibrosis in the kidneys following infection, compared with C5aR1-sufficient mice. This was associated with reduced renal leukocyte infiltration specifically for the population of Ly6Chi proinflammatory monocytes/macrophages and reduced intrarenal gene expression of key proinflammatory and profibrogenic factors in C5aR1-/- mice following infection. Antagonizing C5aR1 decreased renal bacterial load, tissue inflammation and tubulointerstitial fibrosis. Ex vivo and in vitro studies showed that under infection conditions, C5a/C5aR1 interaction upregulated the production of proinflammatory and profibrogenic factors by renal tubular epithelial cells and monocytes/macrophages, whereas the phagocytic function of monocytes/macrophages was down-regulated. Thus, C5aR1-dependent bacterial colonization of the tubular epithelium, C5a/C5aR1-mediated upregulation of local inflammatory responses to uropathogenic E. coli and impairment of phagocytic function of phagocytes contribute to persistent bacterial colonization of the kidney, chronic renal inflammation and subsequent tubulointerstitial fibrosis.
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Affiliation(s)
- Naheed Choudhry
- Medical Research Council Centre for Transplantation, King's College London, Guy's Hospital, London, UK
| | - Ke Li
- Core Research Laboratory, the Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, Shaanxi, People's Republic of China.
| | - Ting Zhang
- Core Research Laboratory, the Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, Shaanxi, People's Republic of China
| | - Kun-Yi Wu
- Core Research Laboratory, the Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, Shaanxi, People's Republic of China
| | - Yun Song
- Core Research Laboratory, the Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, Shaanxi, People's Republic of China
| | - Conrad A Farrar
- Medical Research Council Centre for Transplantation, King's College London, Guy's Hospital, London, UK
| | - Na Wang
- Core Research Laboratory, the Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, Shaanxi, People's Republic of China
| | - Cheng-Fei Liu
- Core Research Laboratory, the Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, Shaanxi, People's Republic of China
| | - Qi Peng
- Medical Research Council Centre for Transplantation, King's College London, Guy's Hospital, London, UK
| | - Weiju Wu
- Medical Research Council Centre for Transplantation, King's College London, Guy's Hospital, London, UK
| | - Steven H Sacks
- Medical Research Council Centre for Transplantation, King's College London, Guy's Hospital, London, UK
| | - Wuding Zhou
- Medical Research Council Centre for Transplantation, King's College London, Guy's Hospital, London, UK.
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Paniagua-Contreras GL, Monroy-Pérez E, Rodríguez-Moctezuma JR, Domínguez-Trejo P, Vaca-Paniagua F, Vaca S. Virulence factors, antibiotic resistance phenotypes and O-serogroups of Escherichia coli strains isolated from community-acquired urinary tract infection patients in Mexico. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2015; 50:478-485. [PMID: 26433755 DOI: 10.1016/j.jmii.2015.08.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 06/24/2015] [Accepted: 08/31/2015] [Indexed: 11/30/2022]
Abstract
BACKGROUND/PURPOSE Uropathogenic Escherichia coli (UPEC) strains isolated from patients with community-acquired urinary tract infections (UTIs) were assessed to determine the prevalence of virulence genes, antibiotic resistance, and the O-serogroup of the strains. METHODS Consenting patients with community-acquired UTI were enrolled at Unidad Médica Familiar Number 64 (Instituto Mexicano del Seguro Social, Estado de Mexico, Mexico) and 321 urine samples were collected. Polymerase chain reaction (PCR) was used to assess 24 virulence genes and 14 O-serogroups. The Kirby-Bauer method was used to evaluate the antibiotic susceptibility of the isolated strains to 12 commonly used antibiotics. RESULTS A total of 194 strains were identified as E. coli using standard biochemical tests, followed by PCR amplification of 16S ribosomal RNA gene. Only 58.2% of the strains belonged to the assessed 14 O-serogroups. The serogroups O25, O15, O8, and O75 were present in 20.6%, 17%, 6.1%, and 4.6% of strains, respectively. The most frequently occurring virulence genes among UPEC strains included kpsMT (92.2% strains), usp (87.1%), irp2 (79.3%), iha (64.9%), fim (61.3%), set (36%), astA (33.5%), pap (24.7%), and papGII (21.1%). In addition, 97% of the strains were multi-drug resistant (coresistance to 3-11 antibiotics). CONCLUSION The isolated UPEC strains predominantly belonged to three serogroups (O25, O15, and O8), harboured numerous virulence genes, and are multiresistant to antibiotics. The findings of this study could be used to orient UTI treatment strategies and in epidemiological studies in Mexico.
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Affiliation(s)
| | - Eric Monroy-Pérez
- FES Iztacala, Universidad Nacional Autónoma de México, Estado de Mexico, Mexico
| | | | - Pablo Domínguez-Trejo
- Unidad Médica Familiar Number 64, Instituto Mexicano del Seguro Social, Juárez, Mexico
| | | | - Sergio Vaca
- FES Iztacala, Universidad Nacional Autónoma de México, Estado de Mexico, Mexico.
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Maldonado-Gomez MX, Lee H, Barile D, Lu M, Hutkins RW. Adherence inhibition of enteric pathogens to epithelial cells by bovine colostrum fractions. Int Dairy J 2015. [DOI: 10.1016/j.idairyj.2014.08.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Zaw MT, Yamasaki E, Yamamoto S, Nair GB, Kawamoto K, Kurazono H. Uropathogenic specific protein gene, highly distributed in extraintestinal uropathogenic Escherichia coli, encodes a new member of H-N-H nuclease superfamily. Gut Pathog 2013; 5:13. [PMID: 23759109 PMCID: PMC3685522 DOI: 10.1186/1757-4749-5-13] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Accepted: 06/05/2013] [Indexed: 01/12/2023] Open
Abstract
Background The uropathogenic specific protein (Usp) and three OrfU proteins (OrfU1, OrfU2 and OrfU3) are encoded in the putative small pathogenicity island which is closely associated with Uropathogenic Escherichia coli. Although homology search revealed that Usp and OrfUs have a homology with nuclease-type bacteriocins, which possess H-N-H nuclease motif, and immunity proteins respectively, the molecular activity of these proteins was never investigated. In this study, we try to over-express Usp in E. coli, purify Usp and characterize its molecular activity. Method Recombinant Usp protein was expressed in E. coli BL21(DE3) cells together with 6× Histidine tagged OrfU1 (OrfU1-His) protein, and purified with affinity chromatography using Ni2+ chelating agarose. The nuclease activity of the purified Usp was examined in vitro by using plasmid DNA as a substrate. The importance of H-N-H motif in nuclease activity of Usp was examined by site-directed mutagenesis study. Results We revealed that pET expression vector encoding Usp alone could not be maintained in E. coli BL21(DE3), and insertion of the orfUs as well as usp in the constructed plasmid diminished the toxic effect, suggesting that co-expressed OrfUs masked the activity of Usp. To purify Usp protein, we employed the expression vector encoding untagged Usp together with OrfU1-His. A tight complex formation could be observed between Usp and OrfU1-His, which allowed the purification of Usp in a single chromatographic step: binding of Usp/OrfU1-His complex to Ni2+ chelating agarose followed by elution of Usp from the complex with denaturing reagent. The purified free Usp was found to have the nuclease activity, and the activity was constitutively higher than Usp/OrfU1-His complex. H-N-H motif, which is found in various types of nucleases including a subfamily of nuclease-type bacteriocin, had been identified in the C-terminal region of Usp. Site-directed mutagenesis study showed that the H-N-H motif in Usp is indispensable for its nuclease activity. Conclusion This is the first evidence of the molecular activity of the new member of H-N-H superfamily and lays the foundation for the biological characterization of Usp and its inhibitor protein, OrfUs.
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Affiliation(s)
- Myo Thura Zaw
- Division of Food Hygiene, Department of Animal and Food Hygiene, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan.
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13
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Momtaz H, Karimian A, Madani M, Safarpoor Dehkordi F, Ranjbar R, Sarshar M, Souod N. Uropathogenic Escherichia coli in Iran: serogroup distributions, virulence factors and antimicrobial resistance properties. Ann Clin Microbiol Antimicrob 2013; 12:8. [PMID: 23627669 PMCID: PMC3651382 DOI: 10.1186/1476-0711-12-8] [Citation(s) in RCA: 111] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2013] [Accepted: 04/21/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Urinary tract infections (UTIs) are one of the most common bacterial infections with global expansion. These infections are predominantly caused by uropathogenic Escherichia coli (UPEC). METHODS Totally, 123 strains of Escherichia coli isolated from UTIs patients, using bacterial culture method were subjected to polymerase chain reactions for detection of various O- serogroups, some urovirulence factors, antibiotic resistance genes and resistance to 13 different antibiotics. RESULTS According to data, the distribution of O1, O2, O6, O7 and O16 serogroups were 2.43%, besides O22, O75 and O83 serogroups were 1.62%. Furthermore, the distribution of O4, O8, O15, O21 and O25 serogroups were 5.69%, 3.25%, 21.13%, 4.06% and 26.01%, respectively. Overall, the fim virulence gene had the highest (86.17%) while the usp virulence gene had the lowest distributions of virulence genes in UPEC strains isolated from UTIs patients. The vat and sen virulence genes were not detected in any UPEC strains. Totally, aadA1 (52.84%), and qnr (46.34%) were the most prevalent antibiotic resistance genes while the distribution of cat1 (15.44%), cmlA (15.44%) and dfrA1 (21.95%) were the least. Resistance to penicillin (100%) and tetracycline (73.98%) had the highest while resistance to nitrofurantoin (5.69%) and trimethoprim (16.26%) had the lowest frequencies. CONCLUSIONS This study indicated that the UPEC strains which harbored the high numbers of virulence and antibiotic resistance genes had the high ability to cause diseases that are resistant to most antibiotics. In the current situation, it seems that the administration of penicillin and tetracycline for the treatment of UTIs is vain.
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Affiliation(s)
- Hassan Momtaz
- Department of Microbiology, ShahreKord Branch, Islamic Azad University, P.O. Box: 166, ShahreKord, Iran.
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14
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Chiou YY, Chen MJ, Chiu NT, Lin CY, Tseng CC. Bacterial Virulence Factors are Associated With Occurrence of Acute Pyelonephritis but Not Renal Scarring. J Urol 2010; 184:2098-102. [DOI: 10.1016/j.juro.2010.06.135] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2010] [Indexed: 10/19/2022]
Affiliation(s)
- Yuan-Yow Chiou
- Department of Pediatrics and Institute of Clinical Medicine, National Cheng Kung University Medical College and Hospital, Rende Shiang, Tainan, Taiwan
| | - Mei-Ju Chen
- Department of Long-Term Care, Chung Hwa University of Medical Technology, Rende Shiang, Tainan, Taiwan
| | - Nan-Tsing Chiu
- Department of Nuclear Medicine, National Cheng Kung University Medical College and Hospital, Rende Shiang, Tainan, Taiwan
| | - Ching-Yuang Lin
- Clinical Immunological Center, China Medical University Medical College and Hospital, Taichung, Taiwan
| | - Chin-Chung Tseng
- Division of Nephrology, Department of Internal Medicine, National Cheng Kung University Medical College and Hospital, Rende Shiang, Tainan, Taiwan
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15
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Klemm P, Vejborg RM, Hancock V. Prevention of bacterial adhesion. Appl Microbiol Biotechnol 2010; 88:451-9. [PMID: 20694794 DOI: 10.1007/s00253-010-2805-y] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Revised: 07/26/2010] [Accepted: 07/27/2010] [Indexed: 11/25/2022]
Abstract
Management of bacterial infections is becoming increasingly difficult due to the emergence and increasing prevalence of bacterial pathogens that are resistant to available antibiotics. Conventional antibiotics generally kill bacteria by interfering with vital cellular functions, an approach that imposes selection pressure for resistant bacteria. New approaches are urgently needed. Targeting bacterial virulence functions directly is an attractive alternative. An obvious target is bacterial adhesion. Bacterial adhesion to surfaces is the first step in colonization, invasion, and biofilm formation. As such, adhesion represents the Achilles heel of crucial pathogenic functions. It follows that interference with adhesion can reduce bacterial virulence. Here, we illustrate this important topic with examples of techniques being developed that can inhibit bacterial adhesion. Some of these will become valuable weapons for preventing pathogen contamination and fighting infectious diseases in the future.
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Affiliation(s)
- Per Klemm
- Technical University of Denmark, Lyngby, Denmark.
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16
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Burmølle M, Thomsen TR, Fazli M, Dige I, Christensen L, Homøe P, Tvede M, Nyvad B, Tolker-Nielsen T, Givskov M, Moser C, Kirketerp-Møller K, Johansen HK, Høiby N, Jensen PØ, Sørensen SJ, Bjarnsholt T. Biofilms in chronic infections - a matter of opportunity - monospecies biofilms in multispecies infections. ACTA ACUST UNITED AC 2010; 59:324-36. [PMID: 20602635 DOI: 10.1111/j.1574-695x.2010.00714.x] [Citation(s) in RCA: 278] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
It has become evident that aggregation or biofilm formation is an important survival mechanism for bacteria in almost any environment. In this review, we summarize recent visualizations of bacterial aggregates in several chronic infections (chronic otitis media, cystic fibrosis, infection due to permanent tissue fillers and chronic wounds) both as to distribution (such as where in the wound bed) and organization (monospecies or multispecies microcolonies). We correlate these biofilm observations to observations of commensal biofilms (dental and intestine) and biofilms in natural ecosystems (soil). The observations of the chronic biofilm infections point toward a trend of low bacterial diversity and sovereign monospecies biofilm aggregates even though the infection in which they reside are multispecies. In contrast to this, commensal and natural biofilm aggregates contain multiple species that are believed to coexist, interact and form biofilms with high bacterial and niche diversity. We discuss these differences from both the diagnostic and the scientific point of view.
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Affiliation(s)
- Mette Burmølle
- Department of Biology, University of Copenhagen, Denmark
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17
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Mann S, Chen YPP. Bacterial genomic G+C composition-eliciting environmental adaptation. Genomics 2010; 95:7-15. [DOI: 10.1016/j.ygeno.2009.09.002] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2009] [Revised: 08/18/2009] [Accepted: 09/01/2009] [Indexed: 01/12/2023]
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18
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Singh KV, Nallapareddy SR, Murray BE. Importance of the ebp (endocarditis- and biofilm-associated pilus) locus in the pathogenesis of Enterococcus faecalis ascending urinary tract infection. J Infect Dis 2007; 195:1671-7. [PMID: 17471437 PMCID: PMC2680192 DOI: 10.1086/517524] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2006] [Accepted: 01/02/2007] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND We recently demonstrated that the ubiquitous Enterococcus faecalis ebp (endocarditis- and biofilm-associated pilus) operon is important for biofilm formation and experimental endocarditis. Here, we assess its role in murine urinary tract infection (UTI) by use of wild-type E. faecalis OG1RF and its nonpiliated, ebpA allelic replacement mutant (TX5475). METHODS OG1RF and TX5475 were administered transurethrally either at an ~1 : 1 ratio (competition assay) or individually (monoinfection). Kidney pairs and urinary bladders were cultured 48 h after infection. These strains were also tested in a peritonitis model. RESULTS No differences were observed in the peritonitis model. In mixed UTIs, OG1RF significantly outnumbered TX5475 in kidneys (P=.0033) and bladders (P< or =.0001). More OG1RF colony-forming units were also recovered from the kidneys of monoinfected mice at the 4 inocula tested (P=.015 to P=.049), and 50% infective doses of OG1RF for kidneys and bladder (9.1x10(1) and 3.5x10(3) cfu, respectively) were 2-3 log(10) lower than those of TX5475. Increased tropism for the kidney relative to the bladder was observed for both OG1RF and TX5475. CONCLUSION The ebp locus, part of the core genome of E. faecalis, contributes to infection in an ascending UTI model and is the first such enterococcal locus shown to be important in this site.
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Affiliation(s)
- Kavindra V Singh
- Center for the Study of Emerging and Reemerging Pathogens, Division of Infectious Diseases, University of Texas Medical School at Houston, Houston, TX 77030, USA
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19
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Abstract
PURPOSE OF REVIEW Urinary tract infection is the second most common bacterial infection in children. It may cause renal scarring leading to secondary hypertension and chronic kidney disease. Recent information has greatly improved our understanding of the pathogenesis of urinary tract infection and renal scarring. RECENT FINDINGS Urothelium, an anatomical barrier for innate immune responses, expresses toll-like receptors with the capacity to recognize pathogen-associated molecular patterns. Engagement of toll-like receptors can lead to uroepithelial cell activation and production of inflammatory mediators. These include complement proteins, other bactericidal peptides, cytokines, chemokines, defensins and adhesion molecules. The resulting inflammatory infiltrate serves to aid bacterial clearance but can also lead to renal damage. Furthermore, interactions between urinary proteins, such as Tamm-Horsfall protein, and TLR-4 add to the complexity of this defense system. Interindividual variability in cellular response may in part be responsible for variable clinical outcomes. Polymorphisms in a number of candidate genes in this host defense mechanism may be involved in determining those patients who are susceptible to recurrent infections and renal scarring following urinary tract infection. SUMMARY Further understanding of the basic molecular mechanisms of urinary tract infection and translating these bench data to the bedside holds the promise of improving diagnosis and therapeutic strategies of treating urinary tract infection and preventing recurrence and renal scarring.
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Affiliation(s)
- Robert H Mak
- Division of Pediatric Nephrology, Oregon Health & Science University, Portland, Oregon 97239, USA.
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20
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Bidet P, Bonacorsi S, Clermont O, De Montille C, Brahimi N, Bingen E. Multiple insertional events, restricted by the genetic background, have led to acquisition of pathogenicity island IIJ96-like domains among Escherichia coli strains of different clinical origins. Infect Immun 2005; 73:4081-7. [PMID: 15972496 PMCID: PMC1168593 DOI: 10.1128/iai.73.7.4081-4087.2005] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We investigated the dissemination of pathogenicity island (PAI) II(J96)-like elements (hra, hly, cnf1, and pap) among 455 Escherichia coli isolates from children and adults with urinary tract infection (UTI), neonates with meningitis or colonized healthy neonates, and 74 reference strains by means of PCR phylogenetic grouping, ribotyping, and PCR analysis of virulence genes. Colocalization of these genes was documented by pulsed-field gel electrophoresis followed by Southern hybridization and long-range PCR (LRPCR) between the hra and the papG alleles. Site-specific insertion of the PAI was determined by LRPCR between hra and tRNA flanking sequences. hra, hly, and cnf1 were found in 113 isolates and consistently colocalized, constituting the backbone of PAI II(J96)-like domains. The prevalence of PAI II(J96)-like domains was significantly higher among UTI isolates than among neonatal meningitis and commensal isolates. These domains were restricted to a few ribotypes of group B2. In contrast to the consistent colocalization of hra, hly, and cnf1, the pap operon was varied: 12% of strains exhibited an allelic exchange of the papG class III allele (papGIII) for the papG class II allele (papGII) (only UTI isolates), and the pap operon was deleted in 23% of strains. No strains harbored papGIII outside the PAI, which appears to be the only source of this allele. PAI II(J96)-like domains were inserted in the vicinities of three different tRNAs--pheU (54%), leuX (29%), and pheV (15%)--depending on the genetic backgrounds and origins of the isolates. Multiple insertional events restricted by the genetic background have thus led to PAI II(J96) acquisition. Specific genetic backgrounds and insertion sites may have played a role in additional recombination processes for E. coli adaptation to different ecological niches.
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Affiliation(s)
- Philippe Bidet
- Laboratoire d'études de génétique bactérienne dans les infections de l'enfant (EA3105), Université Denis Diderot--Paris 7, Service de Microbiologie, Hôpital Robert Debré (AP-HP), Paris, France
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21
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Gascón I, Pascual S, Plazas J, Sánchez J, Francés R, Más P, Zapater P, Pérez-Mateo M, Such J. Norfloxacin decreases bacterial adherence of quinolone-resistant strains of Escherichia coli isolated from patients with cirrhosis. Aliment Pharmacol Ther 2005; 21:701-7. [PMID: 15771756 DOI: 10.1111/j.1365-2036.2005.02366.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
Abstract
BACKGROUND Long-term administration of norfloxacin is recommended for secondary prophylaxis of spontaneous bacterial peritonitis in cirrhosis, but it may be associated with the development of quinolone-resistant bacteria in stools. However, these bacteria rarely cause infections. AIM To assess bacterial adherence of either quinolone-sensitive or -resistant Escherichia coli obtained from stools of cirrhotic patients, as one of the main virulence factors, and its variations when sub-minimum inhibitory concentration of norfloxacin were added to the medium. METHODS E. coli strains were co-cultured with oral epithelial cells obtained from patients in presence/absence of norfloxacin. Bacterial adherence was measured as percentage of cells exhibiting positive adherence and the number of bacteria attached to epithelial cells. RESULTS 37 sensitive and 22 resistant E. coli strains were studied. Bacterial adherence was similar in both series (78% vs. 81%, P = N.S.), and these percentages were similarly and significantly reduced when subminimum inhibitory concentration of norfloxacin was added to the culture medium (P < 0.001). CONCLUSIONS Bacterial adherence of E. coli obtained from patients with cirrhosis is unrelated to the sensitivity/resistance to quinolones, and is similarly reduced in both cases when subminimum inhibitory concentration of norfloxacin is added to the medium.
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Affiliation(s)
- I Gascón
- Microbiology Department, Hospital General Universitario, 03010 Alicante, Spain
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22
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Johnson JR. Microbial virulence determinants and the pathogenesis of urinary tract infection. Infect Dis Clin North Am 2003; 17:261-78, viii. [PMID: 12848470 DOI: 10.1016/s0891-5520(03)00027-8] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The most frequent and best-studied agent of urinary tract infection (UTI) is Escherichia coli, which serves as a useful model pathogen for understanding microbial virulence in relation to UTI pathogenesis. The E. coli strains that cause most UTIs and other extraintestinal E. coli infections represent a highly specialized subset of the total E. coli population. The enhanced virulence potential of such strains, which collectively are known as uropathogenic E. coli or extraintestinal pathogenic E. coli (ExPEC), is thought to be caused mainly by their multiple virulence factors. These virulence factors include diverse adhesins, siderophores, toxins, polysaccharide coatings, and other properties that assist the bacteria in avoiding or subverting host defenses, injuring or invading host cells and tissues, and stimulating a noxious inflammatory response. Although the true evolutionary basis for ExPEC is unknown, the virulence factors of ExPEC serve as useful epidemiologic markers and in the future may provide effective targets for anti-UTI interventions.
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Affiliation(s)
- James R Johnson
- Infectious Diseases (111F), Veterans Affairs Medical Center, One Veteran's Drive, Minneapolis, MN 55417, USA.
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23
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Abstract
Antibiotics are usually used to prevent childhood recurrent urinary tract infections: cystitis or pyelonephritis. The mechanism of action of these antibiotics, although imperfectly known, seems to be double: the antibiotic acts by its bactericidal effect, but also probably for minimal concentrations by reducing adhesion capability of bacteria to the urothelium. The most commonly used molecules are cotrimoxazole, trimethoprime, pivmecillinam, cefaclor and nalidixic acid. However all have not been studied rigorously as for their prophylactic capacity, and in particular very little is known for patients presenting with vesico-ureteral reflux.
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Affiliation(s)
- S Nathanson
- Hôpital André-Mignot, 177, avenue de Versailles, 78150 Le Chesnay, France.
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24
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Johnson JR, Russo TA. Extraintestinal pathogenic Escherichia coli: "the other bad E coli". THE JOURNAL OF LABORATORY AND CLINICAL MEDICINE 2002; 139:155-62. [PMID: 11944026 DOI: 10.1067/mlc.2002.121550] [Citation(s) in RCA: 240] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Extraintestinal pathogenic Escherichia coli (ExPEC), the specialized strains of E coli that cause most extraintestinal E coli infections, represent a major but little-appreciated health threat. Although the reasons for their evolution remain mysterious, by virtue of their numerous virulence traits ExPEC clearly possess a unique ability to cause disease outside the host intestinal tract. Broader appreciation of the existence and importance of ExPEC and better understandings of their distinctive virulence mechanisms, reservoirs, and transmission pathways may lead to effective preventive interventions against the morbid and costly infections ExPEC cause.
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Affiliation(s)
- James R Johnson
- Infectious Diseases (111F), Medical Service, Veterans Affairs Medical Center, 1 Veterans Drive, Minneapolis, MN 55417, USA.
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25
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Ozaki K, Hanazawa S. Porphyromonas gingivalis fimbriae inhibit caspase-3-mediated apoptosis of monocytic THP-1 cells under growth factor deprivation via extracellular signal-regulated kinase-dependent expression of p21 Cip/WAF1. Infect Immun 2001; 69:4944-50. [PMID: 11447172 PMCID: PMC98586 DOI: 10.1128/iai.69.8.4944-4950.2001] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Apoptotic regulation of monocytes/macrophages appears to be closely associated with chronic inflammatory reactions. Since it was demonstrated earlier that certain bacterial cell components are involved in apoptotic regulation of these cells, in the present study, we investigated whether the bacterial fimbria, an important cell structure involved in bacterial adherence to host cells, regulates apoptosis of human monocytic THP-1 cells induced under growth factor deprivation. To investigate this point, we used fimbriae of Porphyromonas gingivalis, a pathogen causing periodontal disease, which is a chronic inflammatory disease. The fimbriae inhibited apoptosis of the cells under growth factor deprivation. This inhibitory action of the fimbriae was completely neutralized by anti-fimbrial antibody. The fimbriae stimulated activation of extracellular signal-regulated kinase (ERK) and expression of cyclin-dependent kinase inhibitor p21 Cip/WAF1 (p21) in the cells. The stimulatory effect of the fimbriae on the expression of the p21 protein was inhibited by treatment with PD98059, a specific inhibitor of ERK. The cell apoptosis was inhibited by treatment with Ac-DEVD-CHO, an inhibitor of caspase-3. The fimbriae inhibited the serum withdrawal-induced cleavage of the caspase-3 proform and poly(ADP-ribose) polymerase, one of the caspase-3 substrates. Furthermore, PD98059 and antisense p21 oligonucleotide blocked the fimbrial inhibition of apoptosis and caspase-3 activation of the cells induced by serum withdrawal. These results show that the bacterial fimbriae inhibited apoptosis of THP-1 cells induced under growth factor deprivation via ERK-dependent expression of p21. The present study suggests that bacterial fimbriae act as potent regulators of chronic inflammatory disease, e.g., periodontal disease, through blocking apoptosis of monocytes/macrophages.
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Affiliation(s)
- K Ozaki
- Department of Oral Microbiology, Meikai University School of Dentistry, Keyakidai, Sakado City, Saitama 350-0283, Japan
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26
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Springall T, Sheerin NS, Abe K, Holers VM, Wan H, Sacks SH. Epithelial secretion of C3 promotes colonization of the upper urinary tract by Escherichia coli. Nat Med 2001; 7:801-6. [PMID: 11433344 DOI: 10.1038/89923] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
To assess the role of complement in renal infection, we studied a model of Escherichia coli-induced pyelonephritis in mice deficient in complement components C3 and C4. Renal infection occurred less frequently in C3- and C4-deficient mice compared with wild-type mice. In vitro, renal epithelial cells internalized fewer bacteria in the absence of C3 or in the presence of blockade of C3 bound to the bacteria. Moreover, upregulation of epithelial C3 production by stimulation with lipopolysaccharide enhanced bacterial internalization. Here we provide evidence that uropathogenic E. coli might use host C3 to invade the renal epithelium and that local complement production is sufficient for the bacteria to achieve this effect.
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Affiliation(s)
- T Springall
- Department of Nephrology and Transplantation, Guy's Hospital, GKT, King's College London, UK
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27
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Abstract
Virulence factors of pathogenic bacteria (adhesins, toxins, invasins, protein secretion systems, iron uptake systems, and others) may be encoded by particular regions of the prokaryotic genome termed pathogenicity islands. Pathogenicity islands were first described in human pathogens of the species Escherichia coli, but have recently been found in the genomes of various pathogens of humans, animals, and plants. Pathogenicity islands comprise large genomic regions [10-200 kilobases (kb) in size] that are present on the genomes of pathogenic strains but absent from the genomes of nonpathogenic members of the same or related species. The finding that the G+C content of pathogenicity islands often differs from that of the rest of the genome, the presence of direct repeats at their ends, the association of pathogenicity islands with transfer RNA genes, the presence of integrase determinants and other mobility loci, and their genetic instability argue for the generation of pathogenicity islands by horizontal gene transfer, a process that is well known to contribute to microbial evolution. In this article we review these and other aspects of pathogenicity islands and discuss the concept that they represent a subclass of genomic islands. Genomic islands are present in the majority of genomes of pathogenic as well as nonpathogenic bacteria and may encode accessory functions which have been previously spread among bacterial populations.
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Affiliation(s)
- J Hacker
- Institut für Molekulare Infektionsbiologie, Universität Würzburg, D-97070 Würzburg, Germany.
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28
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Mattoo S, Miller JF, Cotter PA. Role of Bordetella bronchiseptica fimbriae in tracheal colonization and development of a humoral immune response. Infect Immun 2000; 68:2024-33. [PMID: 10722598 PMCID: PMC97382 DOI: 10.1128/iai.68.4.2024-2033.2000] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Fimbriae are filamentous, cell surface structures which have been proposed to mediate attachment of Bordetella species to respiratory epithelium. Bordetella bronchiseptica has four known fimbrial genes: fim2, fim3, fimX, and fimA. While these genes are unlinked on the chromosome, their protein products are assembled and secreted by a single apparatus encoded by the fimBCD locus. The fimBCD locus is embedded within the fha operon, whose genes encode another putative adhesin, filamentous hemagglutinin (FHA). We have constructed a Fim(-) B. bronchiseptica strain, RB63, by introducing an in-frame deletion extending from fimB through fimD. Western blot analysis showed that RB63 is unable to synthesize fimbriae but is unaffected for FHA expression. Using this mutant, we assessed the role of fimbriae in pathogenesis in vitro and in vivo in natural animal hosts. Although RB63 was not significantly defective in its ability to adhere to various tissue culture cell lines, including human laryngeal HEp-2 cells, it was considerably altered in its ability to cause respiratory tract infections in rats. The number of DeltafimBCD bacteria recovered from the rat trachea at 10 days postinoculation was significantly decreased compared to that of wild-type B. bronchiseptica and was below the limit of detection at 30 and 60 days postinoculation. The number of bacteria recovered from the nasal cavity and larynx was not significantly different between RB63 and the wild-type strain at any time point. The ability of fimbriae to mediate initial attachment to tracheal tissue was tested in an intratracheal inoculation assay. Significantly fewer RB63 than wild-type bacteria were recovered from the tracheas at 24 h after intratracheal inoculation. These results demonstrate that fimbriae are involved in enhancing the ability of B. bronchiseptica to establish tracheal colonization and are essential for persistent colonization at this site. Interestingly, anti-Bordetella serum immunoglobulin M (IgM) levels were significantly lower in animals infected with RB63 than in animals infected with wild-type B. bronchiseptica at 10 days postinoculation. Even at 30 days postinoculation, RB63-infected animals had lower serum anti-Bordetella antibody titers in general. This disparity in antibody profiles suggests that fimbriae are also important for the induction of a humoral immune response.
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Affiliation(s)
- S Mattoo
- Department of Microbiology, UCLA School of Medicine, University of California, Los Angeles, California 90095-1747, USA
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29
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Johnson JR, Stell AL, Scheutz F, O'Bryan TT, Russo TA, Carlino UB, Fasching C, Kavle J, Van Dijk L, Gaastra W. Analysis of the F antigen-specific papA alleles of extraintestinal pathogenic Escherichia coli using a novel multiplex PCR-based assay. Infect Immun 2000; 68:1587-99. [PMID: 10678978 PMCID: PMC97319 DOI: 10.1128/iai.68.3.1587-1599.2000] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/1999] [Accepted: 12/15/1999] [Indexed: 11/20/2022] Open
Abstract
Polymorphisms in PapA, the major structural subunit and antigenic determinant of P fimbriae of extraintestinal pathogenic Escherichia coli, are of considerable epidemiological, phylogenetic, and immunotherapeutic importance. However, to date, no method other than DNA sequencing has been generally available for their detection. In the present study, we developed and rigorously validated a novel PCR-based assay for the 11 recognized variants of papA and then used the new assay to assess the prevalence, phylogenetic distribution, and bacteriological associations of the papA alleles among 75 E. coli isolates from patients with urosepsis. In comparison with conventional F serotyping, the assay was extremely sensitive and specific, evidence that papA sequences are highly conserved within each of the traditionally recognized F serotypes despite the diversity observed among F types. In certain strains, the assay detected serologically occult copies of papA, of which some were shown to represent false-negative serological results and others were shown to represent the presence of nonfunctional pap fragments. Among the urosepsis isolates, the assay revealed considerable segregation of papA alleles according to O:K:H serotype, consistent with vertical transmission within clones, but with exceptions which strongly suggested horizontal transfer of papA alleles between lineages. Sequencing of papA from two strains that were papA positive by probe and PCR but F negative in the new PCR assay led to the discovery of two novel papA variants, one of which was actually more prevalent among the urosepsis isolates than were several of the known papA alleles. These findings provide novel insights into the papA alleles of extraintestinal pathogenic E. coli and indicate that the F PCR assay represents a versatile new molecular tool for epidemiological and phylogenetic investigations which should make rapid, specific detection of papA alleles available to any laboratory with PCR capability.
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Affiliation(s)
- J R Johnson
- Medical Service, VA Medical Center, and Department of Medicine, University of Minnesota, Minneapolis, Minnesota, USA.
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30
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DeSouza MM, Surveyor GA, Price RE, Julian J, Kardon R, Zhou X, Gendler S, Hilkens J, Carson DD. MUC1/episialin: a critical barrier in the female reproductive tract. J Reprod Immunol 1999; 45:127-58. [PMID: 10674981 DOI: 10.1016/s0165-0378(99)00046-7] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The female reproductive tract must resist microbial infections as well as support embryonic development, implantation and placentation. Reproductive tract mucins, in general, and Muc1/episialin, in particular, play key roles in implantation related events and in protection from microbial infection. High levels of mucin expression in the lower reproductive tract presumably affords protection against infection while down-regulation of uterine mucins has been suggested to provide access to the uterine surface. The present studies demonstrate that mucins, particularly Muc1, are effective barriers to embryo attachment. Furthermore, a strain of female Muc1 null mice in normal housing displays chronic infection and inflammation of the lower reproductive tract and markedly reduced fertility rates. This phenotype is not observed when Muc1 nulls are housed in a pathogen-free environment indicating that this phenotype results from chronic microbial exposure. Only normal endogenous flora were isolated from the reproductive tracts of affected Muc1 null mice, suggesting that these bacterial species become opportunistic with loss of the mucin barrier. Staphylococcal adherence to lower reproductive tract epithelia was found to be mediated by cell surface mucin carbohydrates. Collectively, these studies demonstrate a critical barrier role for Muc1 in various aspects of female reproductive tract physiology.
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Affiliation(s)
- M M DeSouza
- Department of Biological Sciences, University of Delaware, Newark 19716-2590, USA
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