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Axell-House DB, Ashley PA, Egge SL, Tran TT, Pedroza C, Zhang M, Dinh AQ, Simar SR, Sahasrabhojane PV, Miller WR, Shelburne SA, Hanson BM, Arias CA. Clinical Features and Genomic Epidemiology of Bloodstream Infections due to Enterococcal Species Other Than Enterococcus faecalis or E. faecium in Patients With Cancer. Open Forum Infect Dis 2024; 11:ofae288. [PMID: 38835498 PMCID: PMC11148474 DOI: 10.1093/ofid/ofae288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Accepted: 05/15/2024] [Indexed: 06/06/2024] Open
Abstract
Background Non-Enterococcus faecium, non-E. faecalis (NFF) enterococci are a heterogeneous group of clinically pathogenic enterococci that include species with intrinsic low-level vancomycin resistance. Patients with cancer are at increased risk for bacteremia with NFF enterococci, but their clinical and molecular epidemiology have not been extensively described. Methods We conducted a retrospective review of all patients (n = 70) with NFF bacteremia from 2016 to 2022 at a major cancer center. The main outcomes assessed were 30-day mortality, microbiological failure (positive blood cultures for ≥4 days), and recurrence of bacteremia (positive blood culture <14 days after clearance). Whole-genome sequencing was performed on all available NFF (n = 65). Results Patients with hematological malignancies made up 56% of the cohort (77% had leukemia). The majority of solid malignancies (87%) were gastrointestinal in origin. The majority of infections (83%) originated from an intra-abdominal source. The most common NFF species were E. gallinarum (50%) and E. casseliflavus (30%). Most (61%) patients received combination therapy. Bacteremia recurred in 4.3% of patients, there was a 30-day mortality of 23%, and 4.3% had microbiological failure. E. gallinarum and E. casseliflavus isolates were genetically diverse with no spatiotemporal clustering to suggest a single strain. Frequencies of ampicillin resistance (4.3%) and daptomycin resistance (1.9%) were low. Patients with hematologic malignancy had infections with NFF enterococci that harbored more resistance genes than patients with solid malignancy (P = .005). Conclusions NFF bacteremia is caused by a heterogeneous population of isolates and is associated with significant mortality. Hematological malignancy is an important risk factor for infection with NFF resistant to multiple antibiotics.
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Affiliation(s)
- Dierdre B Axell-House
- Division of Infectious Diseases, Department of Medicine, Houston Methodist Hospital, Houston, Texas, USA
- Center for Infectious Diseases, Houston Methodist Research Institute, Houston, Texas, USA
- Department of Medicine, Weill Cornell Medical College, New York City, New York, USA
| | - Patrycja A Ashley
- Division of Infectious Diseases, Department of Medicine, Houston Methodist Hospital, Houston, Texas, USA
| | - Stephanie L Egge
- Division of Infectious Diseases, Department of Medicine, Houston Methodist Hospital, Houston, Texas, USA
- Center for Infectious Diseases, Houston Methodist Research Institute, Houston, Texas, USA
| | - Truc T Tran
- Center for Infectious Diseases, Houston Methodist Research Institute, Houston, Texas, USA
| | - Claudia Pedroza
- Center for Clinical Research and Evidence-Based Medicine, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Meng Zhang
- Center for Clinical Research and Evidence-Based Medicine, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - An Q Dinh
- Center for Infectious Diseases, Houston Methodist Research Institute, Houston, Texas, USA
- Center for Infectious Diseases, School of Public Health, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Shelby R Simar
- Center for Infectious Diseases, School of Public Health, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Pranoti V Sahasrabhojane
- Department of Infectious Diseases, Infection Control, and Employee Health, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - William R Miller
- Division of Infectious Diseases, Department of Medicine, Houston Methodist Hospital, Houston, Texas, USA
- Center for Infectious Diseases, Houston Methodist Research Institute, Houston, Texas, USA
- Department of Medicine, Weill Cornell Medical College, New York City, New York, USA
| | - Samuel A Shelburne
- Department of Infectious Diseases, Infection Control, and Employee Health, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Blake M Hanson
- Center for Infectious Diseases, School of Public Health, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Cesar A Arias
- Division of Infectious Diseases, Department of Medicine, Houston Methodist Hospital, Houston, Texas, USA
- Center for Infectious Diseases, Houston Methodist Research Institute, Houston, Texas, USA
- Department of Medicine, Weill Cornell Medical College, New York City, New York, USA
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Davis BC, Keenum I, Calarco J, Liguori K, Milligan E, Pruden A, Harwood VJ. Towards the standardization of Enterococcus culture methods for waterborne antibiotic resistance monitoring: A critical review of trends across studies. WATER RESEARCH X 2022; 17:100161. [PMID: 36466738 PMCID: PMC9712764 DOI: 10.1016/j.wroa.2022.100161] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Revised: 11/15/2022] [Accepted: 11/17/2022] [Indexed: 06/17/2023]
Abstract
Antibiotic resistance is a major 21st century One Health (humans, animals, environment) challenge whose spread limits options to treat bacterial infections. There is growing interest in monitoring water environments, including surface water and wastewater, which have been identified as key recipients, pathways, and sources of antibiotic resistant bacteria (ARB). Aquatic environments also facilitate the transmission and amplification of ARB. Enterococcus spp. often carry clinically-important antibiotic resistance genes and are of interest as environmental monitoring targets. Enterococcus spp. are Gram-positive bacteria that are typically of fecal origin; however, they are also found in relevant environmental niches, with various species and strains that are opportunistic human pathogens. Although the value of environmental monitoring of antibiotic-resistant Enterococcus has been recognized by both national and international organizations, lack of procedural standardization has hindered generation of comparable data needed to implement integrated surveillance programs. Here we provide a comprehensive methodological review to assess the techniques used for the culturing and characterization of antibiotic-resistant Enterococcus across water matrices for the purpose of environmental monitoring. We analyzed 117 peer-reviewed articles from 33 countries across six continents. The goal of this review is to provide a critical analysis of (i) the various methods applied globally for isolation, confirmation, and speciation of Enterococcus isolates, (ii) the different methods for profiling antibiotic resistance among enterococci, and (iii) the current prevalence of resistance to clinically-relevant antibiotics among Enterococcus spp. isolated from various environments. Finally, we provide advice regarding a path forward for standardizing culturing of Enterococcus spp. for the purpose of antibiotic resistance monitoring in wastewater and wastewater-influenced waters within a global surveillance framework.
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Affiliation(s)
- Benjamin C. Davis
- Via Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, Virginia
| | - Ishi Keenum
- Via Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, Virginia
| | - Jeannette Calarco
- Department of Integrative Biology, University of South Florida, Tampa, Florida
| | - Krista Liguori
- Via Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, Virginia
| | - Erin Milligan
- Via Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, Virginia
| | - Amy Pruden
- Via Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, Virginia
| | - Valerie J. Harwood
- Department of Integrative Biology, University of South Florida, Tampa, Florida
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3
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Shchelik IS, Gademann K. Thiol- and Disulfide-Containing Vancomycin Derivatives Against Bacterial Resistance and Biofilm Formation. ACS Med Chem Lett 2021; 12:1898-1904. [PMID: 34917252 DOI: 10.1021/acsmedchemlett.1c00455] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 10/14/2021] [Indexed: 12/28/2022] Open
Abstract
Antibiotic-resistant and biofilm-associated infections constitute a rapidly growing issue. Use of the last-resort antibiotic vancomycin is under threat due to the increasing appearance of vancomycin-resistant bacteria as well as the formation of biofilms. Herein, we report a series of novel vancomycin derivatives carrying thiol- and disulfide-containing moieties. The new compounds exhibited enhanced antibacterial activity against a broad range of bacterial strains, including vancomycin-resistant microbes and Gram-negative bacteria. Moreover, all obtained derivatives demonstrated improved antibiofilm formation activity against VanB-resistant Enterococcus compared to vancomycin. This work establishes a promising strategy for combating drug-resistant bacterial infections or disrupting biofilm formation and advances the knowledge on the structural optimization of antibiotics with sulfur-containing modifications.
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Affiliation(s)
- Inga S. Shchelik
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Karl Gademann
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
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4
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Guffey AA, Loll PJ. Regulation of Resistance in Vancomycin-Resistant Enterococci: The VanRS Two-Component System. Microorganisms 2021; 9:2026. [PMID: 34683347 PMCID: PMC8541618 DOI: 10.3390/microorganisms9102026] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 09/21/2021] [Accepted: 09/22/2021] [Indexed: 01/20/2023] Open
Abstract
Vancomycin-resistant enterococci (VRE) are a serious threat to human health, with few treatment options being available. New therapeutics are urgently needed to relieve the health and economic burdens presented by VRE. A potential target for new therapeutics is the VanRS two-component system, which regulates the expression of vancomycin resistance in VRE. VanS is a sensor histidine kinase that detects vancomycin and in turn activates VanR; VanR is a response regulator that, when activated, directs expression of vancomycin-resistance genes. This review of VanRS examines how the expression of vancomycin resistance is regulated, and provides an update on one of the field's most pressing questions: How does VanS sense vancomycin?
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Affiliation(s)
| | - Patrick J. Loll
- Department of Biochemistry & Molecular Biology, College of Medicine, Drexel University, Philadelphia, PA 19102, USA;
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Garzón V, Bustos RH, G. Pinacho D. Personalized Medicine for Antibiotics: The Role of Nanobiosensors in Therapeutic Drug Monitoring. J Pers Med 2020; 10:E147. [PMID: 32993004 PMCID: PMC7712907 DOI: 10.3390/jpm10040147] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 09/05/2020] [Accepted: 09/07/2020] [Indexed: 01/01/2023] Open
Abstract
Due to the high bacterial resistance to antibiotics (AB), it has become necessary to adjust the dose aimed at personalized medicine by means of therapeutic drug monitoring (TDM). TDM is a fundamental tool for measuring the concentration of drugs that have a limited or highly toxic dose in different body fluids, such as blood, plasma, serum, and urine, among others. Using different techniques that allow for the pharmacokinetic (PK) and pharmacodynamic (PD) analysis of the drug, TDM can reduce the risks inherent in treatment. Among these techniques, nanotechnology focused on biosensors, which are relevant due to their versatility, sensitivity, specificity, and low cost. They provide results in real time, using an element for biological recognition coupled to a signal transducer. This review describes recent advances in the quantification of AB using biosensors with a focus on TDM as a fundamental aspect of personalized medicine.
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Affiliation(s)
- Vivian Garzón
- PhD Biosciences Program, Universidad de La Sabana, Chía 140013, Colombia;
| | - Rosa-Helena Bustos
- Therapeutical Evidence Group, Clinical Pharmacology, Universidad de La Sabana, Chía 140013, Colombia;
| | - Daniel G. Pinacho
- Therapeutical Evidence Group, Clinical Pharmacology, Universidad de La Sabana, Chía 140013, Colombia;
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Singh H, Das S, Yadav J, Srivastava VK, Jyoti A, Kaushik S. In search of novel protein drug targets for treatment of Enterococcus faecalis infections. Chem Biol Drug Des 2019; 94:1721-1739. [PMID: 31260188 DOI: 10.1111/cbdd.13582] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 06/08/2019] [Accepted: 06/17/2019] [Indexed: 12/27/2022]
Abstract
Enterococcus faecalis (Ef) is one of the major pathogens involved in hospital-acquired infections. It can cause nosocomial bacteremia, surgical wound infection, and urinary tract infection. It is important to mention here that Ef is developing resistance against many commonly occurring antibiotics. The occurrence of multidrug resistance (MDR) and extensive-drug resistance (XDR) is now posing a major challenge to the medical community. In this regard, to combat the infections caused by Ef, we have to look for an alternative. Rational structure-based drug design exploits the three-dimensional structure of the target protein, which can be unraveled by various techniques such as X-ray crystallography or nuclear magnetic resonance (NMR) spectroscopy. In this review, we have discussed the complete picture of Ef infections, the possible treatment available at present, and the alternative treatment options to be explored. This study will help in better understanding of novel biological targets against Ef and the compounds, which are likely to bind with these targets. Using these detailed structural informations, rational structure-based drug design is achievable and tight inhibitors against Ef can be prepared.
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Affiliation(s)
- Harpreet Singh
- Amity Institute of Biotechnology, Amity University Rajasthan, Jaipur, India
| | - Satyajeet Das
- Amity Institute of Biotechnology, Amity University Rajasthan, Jaipur, India
| | - Jyoti Yadav
- Amity Institute of Biotechnology, Amity University Rajasthan, Jaipur, India
| | | | - Anupam Jyoti
- Amity Institute of Biotechnology, Amity University Rajasthan, Jaipur, India
| | - Sanket Kaushik
- Amity Institute of Biotechnology, Amity University Rajasthan, Jaipur, India
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Monticelli J, Knezevich A, Luzzati R, Di Bella S. Clinical management of non-faecium non-faecalis vancomycin-resistant enterococci infection. Focus on Enterococcus gallinarum and Enterococcus casseliflavus/flavescens. J Infect Chemother 2018; 24:237-246. [PMID: 29396199 DOI: 10.1016/j.jiac.2018.01.001] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2017] [Accepted: 01/09/2018] [Indexed: 02/07/2023]
Abstract
Enterococcus gallinarum and Enterococcus casseliflavus/flavescens are enterococci intrinsically resistant to vancomycin belonging to the E. gallinarum group. They are responsible mainly for healthcare-associated infections, in particular bloodstream, urinary tract and surgical wound infections. Diseases due to these bacteria are significantly increasing worldwide, as they are prone to cause infection in patients with concurrent hepatobiliary or oncohematological disorders. Along with their distinguishing vancomycin resistance, due to a chromosomally-encoded VanC operon, their additional intrinsic resistance to many antibiotics other than glycopeptides limits the therapeutic choices. In addition, their intrinsic vancomycin resistance, unlike the vancomycin resistance of Enterococcus faecalis and Enterococcus faecium caused by transmissible plasmids, poses different infection control issues. We focused on the therapeutic and infection control issues of clinical syndromes caused by E. gallinarum and E. casseliflavus/flavescens. We propose therapeutic algorithms on bloodstream infections, endocarditis, central nervous system infections, endophthalmitis and urinary tract infections. The implementation of infection control measures in cases of E. gallinarum and E. casseliflavus/flavescens infection or colonization should be evaluated on a case-by-case basis, especially for epidemic outbreaks or for isolates supposed to harbor a potential transmissible vancomycin-resistance phenotype.
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Affiliation(s)
- Jacopo Monticelli
- Infectious Diseases Division, Azienda Sanitaria Universitaria Integrata di Trieste (ASUITS), Piazza dell'Ospitale 1, 34129, Trieste, Italy.
| | - Anna Knezevich
- Microbiology Division, Azienda Sanitaria Universitaria Integrata di Trieste (ASUITS), Strada di Fiume 447, 34149, Trieste, Italy.
| | - Roberto Luzzati
- Infectious Diseases Division, Azienda Sanitaria Universitaria Integrata di Trieste (ASUITS), Piazza dell'Ospitale 1, 34129, Trieste, Italy.
| | - Stefano Di Bella
- Infectious Diseases Division, Azienda Sanitaria Universitaria Integrata di Trieste (ASUITS), Piazza dell'Ospitale 1, 34129, Trieste, Italy.
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Nomura T, Hashimoto Y, Kurushima J, Hirakawa H, Tanimoto K, Zheng B, Ruan G, Xue F, Liu J, Hisatsune J, Sugai M, Tomita H. New colony multiplex PCR assays for the detection and discrimination of vancomycin-resistant enterococcal species. J Microbiol Methods 2018; 145:69-72. [PMID: 29309802 DOI: 10.1016/j.mimet.2017.12.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 12/27/2017] [Accepted: 12/28/2017] [Indexed: 01/08/2023]
Abstract
New colony multiplex PCR assays for detection of seven types of vancomycin-resistance determinants and eight types of Enterococcus species were developed. For 135 enterococcal isolates examined in this study, these assays showed high sensitivity and specificity, and could provide the rapid and accurate detection of vancomycin-resistant determinants and Enterococcus spp.
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Affiliation(s)
- Takahiro Nomura
- Department of Bacteriology, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan
| | - Yusuke Hashimoto
- Department of Bacteriology, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan
| | - Jun Kurushima
- Department of Bacteriology, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan
| | - Hidetada Hirakawa
- Department of Bacteriology, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan
| | - Koichi Tanimoto
- Laboratory of Bacterial Drug Resistance, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan
| | - Bo Zheng
- Institute of Clinical Pharmacology, Peking University First Hospital, Number 8, Xishiku Street, Xicheng District, Beijing 100034, China
| | - Genjie Ruan
- Institute of Clinical Pharmacology, Peking University First Hospital, Number 8, Xishiku Street, Xicheng District, Beijing 100034, China
| | - Feng Xue
- Institute of Clinical Pharmacology, Peking University First Hospital, Number 8, Xishiku Street, Xicheng District, Beijing 100034, China
| | - Jian Liu
- Institute of Clinical Pharmacology, Peking University First Hospital, Number 8, Xishiku Street, Xicheng District, Beijing 100034, China
| | - Junzo Hisatsune
- Department of Bacteriology, Hiroshima University Graduate School of Biomedical & Health Sciences, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan
| | - Motoyuki Sugai
- Department of Bacteriology, Hiroshima University Graduate School of Biomedical & Health Sciences, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan
| | - Haruyoshi Tomita
- Department of Bacteriology, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan; Laboratory of Bacterial Drug Resistance, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan.
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9
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Iweriebor BC, Obi LC, Okoh AI. Virulence and antimicrobial resistance factors of Enterococcusspp. isolated from fecal samples from piggery farms in Eastern Cape, South Africa. BMC Microbiol 2015; 15:136. [PMID: 26141237 PMCID: PMC4491265 DOI: 10.1186/s12866-015-0468-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2015] [Accepted: 06/18/2015] [Indexed: 11/15/2022] Open
Abstract
Background Enterococci have emerged as an important opportunistic pathogen causing life-threatening infections in hospitals. The emergence of this pathogen is associated with a remarkable capacity to accumulate resistance to antimicrobials and multidrug-resistance particularly to vancomycin, erythromycin and streptomycin have become a major cause of concern for the infectious diseases community. In this paper, we report the prevalence of Enterococcus in respect to species distribution, their virulence and antibiogram profiles. Methods Four hundred fecal samples were collected from two piggery farms in the Eastern Cape Province of South Africa. Enterococcus species were isolated and confirmed with generic specific primers targeting the tuf gene (encoding elongation factor). The confirmed isolates were speciated with enterococci species specific primers that aimed at delineating them into six species that are commonly associated with infections in humans. Antibiotic susceptibility testing was performed by disc diffusion method. Six virulence genes and antimicrobial resistance profiles of the isolates were evaluated molecularly. Results Molecular identification of the presumptive isolates confirmed 320 isolates as Enterococcus spp. Attempt at speciation of the isolates with primers specific for E. faecalis, E. durans, E. casseliflavus, E. hirae and E. faecium delineated them as follows: E. faecalis (12.5 %), E. hirae (31.25 %), E. durans (18.75 %) and E. faecium (37.5 %) while E. casseliflavus was not detected. All the isolates were resistant to vancomycin, streptomycin and cloxacillin, and to at least two different classes of antibiotics, with 300 (93.8 %) isolates being resistant to five or more antibiotics. Also, three out of the six virulence genes were detected in majority of the isolates and they are Adhesion of collagen in E. faecalis (ace) (96.88 %), gelatinase (gelE) (93.13 %) and surface protein (esp) (67.8 %). Conclusion There was high prevalence of multi-resistant vancomycin Enterococcus spp. (VREs) in the fecal samples of pigs in the farms studied, and this poses health implications as vancomycin is an important drug in human medicine. Further studies are needed to determine the spread of vancomycin resistance among bacteria of human origin in the communities.
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Affiliation(s)
- Benson C Iweriebor
- SA-MRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Alice, 5700, Eastern Cape, South Africa. .,Applied and Environmental Microbiology Research Group, Department of Biochemistry and Microbiology, University of Fort Hare, Alice, 5700, Eastern Cape, South Africa.
| | - Larry C Obi
- Academic and Research Division, University of Fort Hare, Alice, 5700, Eastern Cape, South Africa.
| | - Anthony I Okoh
- SA-MRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Alice, 5700, Eastern Cape, South Africa. .,Applied and Environmental Microbiology Research Group, Department of Biochemistry and Microbiology, University of Fort Hare, Alice, 5700, Eastern Cape, South Africa.
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10
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Škedelj V, Perdih A, Brvar M, Kroflič A, Dubbée V, Savage V, O'Neill AJ, Solmajer T, Bešter-Rogač M, Blanot D, Hugonnet JE, Magnet S, Arthur M, Mainardi JL, Stojan J, Zega A. Discovery of the first inhibitors of bacterial enzyme d-aspartate ligase from Enterococcus faecium (Aslfm). Eur J Med Chem 2013; 67:208-20. [DOI: 10.1016/j.ejmech.2013.06.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Revised: 06/01/2013] [Accepted: 06/02/2013] [Indexed: 01/24/2023]
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11
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Ammam F, Meziane-Cherif D, Mengin-Lecreulx D, Blanot D, Patin D, Boneca IG, Courvalin P, Lambert T, Candela T. The functional vanGCd cluster of Clostridium difficile does not confer vancomycin resistance. Mol Microbiol 2013; 89:612-25. [PMID: 23782343 DOI: 10.1111/mmi.12299] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/16/2013] [Indexed: 12/19/2022]
Abstract
vanGCd, a cryptic gene cluster highly homologous to the vanG gene cluster of Enterococcus faecalis is largely spread in Clostridium difficile. Since emergence of vancomycin resistance would have dramatic clinical consequences, we have evaluated the capacity of the vanGCd cluster to confer resistance. We showed that expression of vanGCd is inducible by vancomycin and that VanGCd , VanXYCd and VanTCd are functional, exhibiting D-Ala : D-Ser ligase, D,D-dipeptidase and D-Ser racemase activities respectively. In other bacteria, these enzymes are sufficient to promote vancomycin resistance. Trans-complementation of C. difficile with the vanC resistance operon of Enterococcus gallinarum faintly impacted the MIC of vancomycin, but did not promote vancomycin resistance in C. difficile. Sublethal concentration of vancomycin led to production of UDP-MurNAc-pentapeptide[D-Ser], suggesting that the vanGCd gene cluster is able to modify the peptidoglycan precursors. Our results indicated amidation of UDP-MurNAc-tetrapeptide, UDP-MurNAc-pentapeptide[D-Ala] and UDP-MurNAc-pentapeptide[D-Ser]. This modification is passed on the mature peptidoglycan where a muropeptide Tetra-Tetra is amidated on the meso-diaminopimelic acid. Taken together, our results suggest that the vanGCd gene cluster is functional and is prevented from promoting vancomycin resistance in C. difficile.
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Affiliation(s)
- Fariza Ammam
- EA4043, Faculté de Pharmacie, Université Paris Sud, Châtenay-Malabry, France
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12
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Moura TMD, Cassenego APV, Campos FS, Ribeiro AML, Franco AC, d'Azevedo PA, Frazzon J, Frazzon APG. Detection of vanC1 gene transcription in vancomycin-susceptible Enterococcus faecalis. Mem Inst Oswaldo Cruz 2013; 108:453-6. [PMID: 23828012 PMCID: PMC3970631 DOI: 10.1590/s0074-0276108042013009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Accepted: 04/02/2013] [Indexed: 11/22/2022] Open
Abstract
Here we report the presence and expression levels of the vanC1 and vanC(2/3) genes in vancomycin-susceptible strains of Enterococcus faecalis. The vanC1 and vanC(2/3) genes were located in the plasmid DNA and on the chromosome, respectively. Specific mRNA of the vanC1 gene was detected in one of these strains. Additionally, analysis of the vanC gene sequences showed that these genes are related to the vanC genes of Enterococcus gallinarum and Enterococcus casseliflavus. The presence of vanC genes is useful for the identification of E. gallinarum and E. casseliflavus. Moreover, this is the first report of vanC mRNA in E. faecalis.
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Affiliation(s)
- Tiane Martin de Moura
- Programa de Pós-Graduação em Microbiologia Agrícola e do Ambiente, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil.
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Nam S, Kim MJ, Park C, Park JG, Maeng PJ, Lee GC. Detection and genotyping of vancomycin-resistant Enterococcus spp. by multiplex polymerase chain reaction in Korean aquatic environmental samples. Int J Hyg Environ Health 2013; 216:421-7. [PMID: 23332966 DOI: 10.1016/j.ijheh.2012.12.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Revised: 10/19/2012] [Accepted: 12/18/2012] [Indexed: 10/27/2022]
Abstract
The distribution characteristics of Enterococcus spp., which are indicators of fecal pollution, were investigated at 33 sites within the 3 major water systems of Korea. Enterococci were detected at concentrations ranging from 1 to 37 CFU/100mL in 41 of 132 samples (31.1%) from the 3 major water systems. The overall average detected concentration was 1.2 CFU/100mL, while the average concentration for all detection sites was 5.3 CFU/100mL. After optimized multiplex polymerase chain reaction (PCR) was performed with newly developed VanA, VanB, VanC-1, and VanC-2/3 primers, concentrations of vancomycin-resistant Enterococcus spp. (VRE) ranging from 1 to 23 CFU/100mL were detected in 17 of 132 samples (12.9%). Of 216 individual enterococcal colonies, 64 (29.6%) displayed the VanC genotype. The results of a susceptibility test to vancomycin showed that the range of the minimal inhibitory concentration (MIC), an indicator of bacterial resistance, was 4 to 24μg/mL, with the average MIC at 9.2±4.5μg/mL. Of the bacterial isolates, 1 colony with the VanC-1 genotype was identified as E. gallinarum by 16S rDNA sequencing, whereas the other 63 colonies had the VanC-2/3 genotype and were identified as E. casseliflavus. Although these results imply that the major head bays of Korea are not contaminated with the highly vancomycin-resistant VanA- or VanB-type VREs, the misuse of antibiotics should be prohibited to minimize the presence of VREs and to maintain a safe water supply for protecting the health of the general population. Based on the study results, we also recommend the implementation of a continuous, broad-spectrum inspection program for Enterococcus spp. and VRE contamination in the major head bays. Furthermore, the multiplex PCR method described in this study can be used effectively for this purpose.
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Affiliation(s)
- Sehee Nam
- Department of Microbiology and Molecular Biology, College of Biological Sciences and Biotechnology, Chungnam National University, Daejeon 305-764, Republic of Korea
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14
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Twenty-five years of shared life with vancomycin-resistant enterococci: is it time to divorce? J Antimicrob Chemother 2012. [DOI: 10.1093/jac/dks469] [Citation(s) in RCA: 162] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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15
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Begović J, Jovčić B, Papić-Obradović M, Veljović K, Lukić J, Kojić M, Topisirović L. Genotypic diversity and virulent factors of Staphylococcus epidermidis isolated from human breast milk. Microbiol Res 2012; 168:77-83. [PMID: 23098640 DOI: 10.1016/j.micres.2012.09.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Revised: 08/08/2012] [Accepted: 09/13/2012] [Indexed: 01/15/2023]
Abstract
Staphylococcus epidermidis strains were isolated from the expressed human breast milk (EHM) of 14 healthy donor mothers. Genetic diversity was evaluated using RAPD-PCR REP-PCR and pulse-field gel electrophoresis (PFGE). PFGE allowed the best discrimination of the isolates, since it provided for the greatest diversity of the analyzed genomes. Among the S. epidermidis strains, resistance to gentamicin, tetracycline, erythromycin, clindamycin or vancomycin was detected, whilst four isolates were multiresistant. The results from our study demonstrate that staphylococci from EHM could be reservoirs of resistance genes, since we showed that tetK could be transferred from EHM staphylococci to Gram-negative Escherichia coli. Most of the staphylococcal strains displayed excellent proteolytic and lipolytic activities. Additionally, the presence of ica genes, which was related to their ability to form a biofilm on tissue culture plates, and the presence of virulence factors including autolysin/adhesin AtLE, point to their pathogenic potential.
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Affiliation(s)
- Jelena Begović
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Laboratory for Molecular Genetics of Industrial Microorganisms, Vojvode Stepe 444a, P.O. Box 23, 11010 Belgrade, Serbia.
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Identification of VanN-type vancomycin resistance in an Enterococcus faecium isolate from chicken meat in Japan. Antimicrob Agents Chemother 2012; 56:6389-92. [PMID: 23006756 DOI: 10.1128/aac.00747-12] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Five VanN-type vancomycin-resistant Enterococcus faecium strains were isolated from a sample of domestic chicken meat in Japan. All isolates showed low-level resistance to vancomycin (MIC, 12 mg/liter) and had the same pulsed-field gel electrophoresis profile. The vancomycin resistance was encoded on a large plasmid (160 kbp) and was expressed constitutively. The VanN-type resistance operon was identical to the first resistance operon to be reported, with the exception of a 1-bp deletion in vanT(N) and a 1-bp substitution in vanS(N).
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17
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López M, Tenorio C, Torres C. Study of Vancomycin Resistance in Faecal Enterococci from Healthy Humans and Dogs in Spain a Decade after the Avoparcin Ban in Europe. Zoonoses Public Health 2012; 60:160-7. [DOI: 10.1111/j.1863-2378.2012.01502.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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18
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D-Ala-d-Ser VanN-type transferable vancomycin resistance in Enterococcus faecium. Antimicrob Agents Chemother 2011; 55:4606-12. [PMID: 21807981 DOI: 10.1128/aac.00714-11] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Enterococcus faecium UCN71, isolated from a blood culture, was resistant to low levels of vancomycin (MIC, 16 μg/ml) but susceptible to teicoplanin (MIC, 0.5 μg/ml). No amplification was observed with primers specific for the previously described glycopeptide resistance ligase genes, but a PCR product corresponding to a gene called vanN was obtained using degenerate primers and was sequenced. The deduced VanN protein was related (65% identity) to the d-alanine:d-serine VanL ligase. The organization of the vanN gene cluster, determined using degenerate primers and by thermal asymmetric interlaced (TAIL)-PCR, was similar to that of the vanC operons. A single promoter upstream from the resistance operon was identified by rapid amplification of cDNA ends (RACE)-PCR. The presence of peptidoglycan precursors ending in d-serine and d,d-peptidase activities in the absence of vancomycin indicated constitutive expression of the resistance operon. VanN-type resistance was transferable by conjugation to E. faecium. This is the first report of transferable d-Ala-d-Ser-type resistance in E. faecium.
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Watanabe S, Kobayashi N, Quiñones D, Hayakawa S, Nagashima S, Uehara N, Watanabe N. Genetic diversity of the low-level vancomycin resistance gene vanC-2/vanC-3 and identification of a novel vanC subtype (vanC-4) in Enterococcus casseliflavus. Microb Drug Resist 2010; 15:1-9. [PMID: 19216682 DOI: 10.1089/mdr.2009.0856] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
An intrinsic low-level vancomycin resistance (VanC phenotype) in Enterococcus casseliflavus is conferred by either of two subtypes of vanC genes, that is, vanC-2 or vanC-3, which are genetically closely related. To know genetic diversity of vanC-2/C-3 genes among E. casseliflavus, nucleotide sequences of vanC-2/C-3 and other genetic components in vanC gene cluster (vanXYc, vanTc, vanRc, and vanSc) were analyzed for nine clinical isolates and four standard strains that showed low-level vancomycin resistance. While the vanC-2/C-3 gene sequences showed 93-100% identities among the strains examined, two genetic groups were discriminated by phylogenetic analysis: one closely related to the previously reported vanC-2 or vanC-3 genes (vanC-2/C-3 genotype) with 98-100% identity, and the other distinct from the vanC-2/C-3 genotype (93-95% identity). The latter group found in three clinical isolates was considered as a new subtype of vanC and tentatively designated as vanC-4. Between strains with the vanC-2/C-3 genotype and those with vanC-4, vanXYc genes were also genetically discriminated with 92-93% identity. Similar sequence diversity was observed for vanTc, vanRc, and vanSc (88-93% identity). Clonal relatedness among the E. casseliflavus strains was investigated by phylogenetic analysis of atpA gene. While among E. casseliflavus strains with vanC-2/C-3 genotype, extremely high sequence identities of atpA were found (98.7% or higher), these strains showed slightly lower identity to those with vanC-4 (94-96%). These two groups of E. casseliflavus strains were also discriminated by genotyping with arbitrarily primed PCR. These findings indicated that among E. casseliflavus there are at least two genetic lineages with the distinct vanC genes, that is, a single subtype including previously known vanC-2/C-3, and a novel subtype vanC-4.
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Affiliation(s)
- Shojiro Watanabe
- Department of Hygiene, Sapporo Medical University School of Medicine, Chuo-ku, Sapporo, Japan
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FRANCIOSI E, SETTANNI L, CAVAZZA A, POZNANSKI E. PRESENCE OF ENTEROCOCCI IN RAW COW'S MILK AND “PUZZONE DI MOENA” CHEESE. J FOOD PROCESS PRES 2009. [DOI: 10.1111/j.1745-4549.2008.00262.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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21
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Frechette R, Barrett J. Vancomycin: an update. Expert Opin Investig Drugs 2008. [DOI: 10.1517/13543784.3.9.965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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22
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Yean CY, Yin LS, Lalitha P, Ravichandran M. A nanoplex PCR assay for the rapid detection of vancomycin and bifunctional aminoglycoside resistance genes in Enterococcus species. BMC Microbiol 2007; 7:112. [PMID: 18070365 PMCID: PMC2241610 DOI: 10.1186/1471-2180-7-112] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2007] [Accepted: 12/11/2007] [Indexed: 12/01/2022] Open
Abstract
BACKGROUND Enterococci have emerged as a significant cause of nosocomial infections in many parts of the world over the last decade. The most common enterococci strains present in clinical isolates are E. faecalis and E. faecium which have acquired resistant to either gentamicin or vancomycin. The conventional culture test takes 2-5 days to yield complete information of the organism and its antibiotic sensitivity pattern. Hence our present study was focused on developing a nanoplex PCR assay for the rapid detection of vancomycin and bifunctional aminoglycoside resistant enterococci (V-BiA-RE). This assay simultaneously detects 8 genes namely 16S rRNA of Enterococcus genus, ddl of E. faecalis and E. faecium, aacA-aphD that encodes high level gentamicin resistance (HLGR), multilevel vancomycin resistant genotypes such as vanA, vanB, vanC and vanD and one internal control gene. RESULTS Unique and specific primer pairs were designed to amplify the 8 genes. The specificity of the primers was confirmed by DNA sequencing of the nanoplex PCR products and BLAST analysis. The sensitivity and specificity of V-BiA-RE nanoplex PCR assay was evaluated against the conventional culture method. The analytical sensitivity of the assay was found to be 1 ng at the DNA level while the analytical specificity was evaluated with 43 reference enterococci and non-enterococcal strains and was found to be 100%. The diagnostic accuracy was determined using 159 clinical specimens, which showed that 97% of the clinical isolates belonged to E. faecalis, of which 26% showed the HLGR genotype, but none were vancomycin resistant. The presence of an internal control in the V-BiA-RE nanoplex PCR assay helped us to rule out false negative cases. CONCLUSION The nanoplex PCR assay is robust and can give results within 4 hours about the 8 genes that are essential for the identification of the most common Enterococcus spp. and their antibiotic sensitivity pattern. The PCR assay developed in this study can be used as an effective surveillance tool to study the prevalence of enterococci and their antibiotic resistance pattern in hospitals and farm animals.
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Affiliation(s)
- Chan Yean Yean
- Department of Medical Microbiology and Parasitology, School of Medical Sciences, Universiti Sains Malaysia, Malaysia
| | - Lee Su Yin
- School of Health Sciences, Universiti Sains Malaysia, Malaysia
| | | | - Manickam Ravichandran
- Department of Medical Microbiology and Parasitology, School of Medical Sciences, Universiti Sains Malaysia, Malaysia
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Domingo MC, Huletsky A, Giroux R, Picard FJ, Bergeron MG. vanD and vanG-like gene clusters in a Ruminococcus species isolated from human bowel flora. Antimicrob Agents Chemother 2007; 51:4111-7. [PMID: 17724150 PMCID: PMC2151448 DOI: 10.1128/aac.00584-07] [Citation(s) in RCA: 25] [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
A vancomycin-resistant, anaerobic, gram-positive coccus containing the vanD and vanG-like genes (strain CCRI-16110) was isolated from a human fecal specimen during a hospital surveillance program to detect carriers of vancomycin-resistant enterococci. Comparison of the 16S rRNA gene sequence of strain CCRI-16110 with databases revealed a potentially novel Ruminococcus species that was most similar (<94% identity) to Clostridium and Ruminococcus species. Strain CCRI-16110 was highly resistant to vancomycin and teicoplanin (MICs of >256 microg/ml). The complete DNA sequence of the vanD cluster was most similar (98.2% identity) to that of Enterococcus faecium BM4339, containing the vanD1 allele. An intD gene with 99% identity with that of this E. faecium strain was found to be associated with the vanD gene cluster of this novel anaerobic bacterium. Strain CCRI-16110 also harbors genes encoding putative VanS(G), VanG, and VanT(G) proteins displaying 56, 73.6, and 55% amino acid sequence identity, respectively, compared to the corresponding proteins encoded by the vanG1 and vanG2 operons of Enterococcus faecalis BM4518 and N03-0233. This study reports for the first time an anaerobic bacterium containing the vanD gene cluster. This strain also harbors a partial vanG-like gene cluster. The presence of vanD- and vanG-containing anaerobic bacteria in the human bowel flora suggests that these bacteria may serve as a reservoir for the vanD and vanG vancomycin resistance genes.
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Affiliation(s)
- M-C Domingo
- Centre de Recherche en Infectiologie de l'Université Laval, CHUQ, 2705 boul. Laurier, Québec, Québec G1V 4G2, Canada
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Boyd DA, Du T, Hizon R, Kaplen B, Murphy T, Tyler S, Brown S, Jamieson F, Weiss K, Mulvey MR. VanG-type vancomycin-resistant Enterococcus faecalis strains isolated in Canada. Antimicrob Agents Chemother 2006; 50:2217-21. [PMID: 16723588 PMCID: PMC1479100 DOI: 10.1128/aac.01541-05] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Enterococcus faecalis G1-0247 (vancomycin MIC, 16 microg/ml) was found to harbor a vanG operon 99% identical to the vanG operon in E. faecalis BM4518. E. faecalis N03-0233 (vancomycin MIC, 16 microg/ml) was found to harbor a novel vanG operon, vanG2, on an element in a different chromosomal location than the vanG-harboring elements in G1-0247 and BM4518.
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Affiliation(s)
- David A Boyd
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba
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25
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Bellais S, Arthur M, Dubost L, Hugonnet JE, Gutmann L, van Heijenoort J, Legrand R, Brouard JP, Rice L, Mainardi JL. Aslfm, the D-aspartate ligase responsible for the addition of D-aspartic acid onto the peptidoglycan precursor of Enterococcus faecium. J Biol Chem 2006; 281:11586-94. [PMID: 16510449 DOI: 10.1074/jbc.m600114200] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
D-aspartate ligase has remained the last unidentified peptide bond-forming enzyme in the peptidoglycan assembly pathway of Gram-positive bacteria. Here we show that a two-gene cluster of Enterococcus faecium encodes aspartate racemase (Racfm) and ligase (Aslfm) for incorporation of D-Asp into the side chain of the peptidoglycan precursor. Aslfm was identified as a new member of the ATP-grasp protein superfamily, which includes a diverse set of enzymes catalyzing ATP-dependent carboxylate-amine ligation reactions. Aslfm specifically ligated the beta-carboxylate of D-Asp to the epsilon-amino group of L-Lys in the nucleotide precursor UDP-N-acetylmuramyl-pentapeptide. D-iso-asparagine was not a substrate of Aslfm, indicating that the presence of this amino acid in the peptidoglycan of E. faecium results from amidation of the alpha-carboxyl of D-Asp after its addition to the precursor. Heterospecific expression of the genes encoding Racfm and Aslfm in Enterococcus faecalis led to production of stem peptides substituted by D-Asp instead of L-Ala2, providing evidence for the in vivo specificity and function of these enzymes. Strikingly, sequencing of the cross-bridges revealed that substitution of L-Ala2 by D-Asp is tolerated by the d,d-transpeptidase activity of the penicillin-binding proteins both in the acceptor and in the donor substrates. The Aslfm ligase appears as an attractive target for the development of narrow spectrum antibiotics active against multiresistant E. faecium.
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26
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Asano Y, Lübbehüsen TL. Enzymes acting on peptides containing D-amino acid. J Biosci Bioeng 2005; 89:295-306. [PMID: 16232749 DOI: 10.1016/s1389-1723(00)88949-5] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2000] [Accepted: 02/21/2000] [Indexed: 11/17/2022]
Abstract
Mainly microorganisms but only a few higher organisms are presently known to express enzymes that hydrolyze peptides containing D-amino acids. These enzymes can be involved in proceedings at the bacterial cell wall, in either assembly or modification, and thus cause resistance to glycopeptide antibiotics, or mediate resistance against beta-lactam antibiotics. In other cases the in vivo function is still unknown. New enzymes screened from nature, such as D-aminopeptidase, D-amino acid amidase, alkaline D-peptidase or D-aminoacylase, offer potential application in the production of D-amino acids, the synthesis of D-amino acid oligomers by promoting the reversed reaction under appropriate conditions, or in the field of semi-synthetic antibiotics.
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Affiliation(s)
- Y Asano
- Biotechnology Research Center, Toyama Prefectural University, 5180 Kurokawa, Kosugi, Toyama 939-0398, Japan
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Fraimow H, Knob C, Herrero IA, Patel R. Putative VanRS-like two-component regulatory system associated with the inducible glycopeptide resistance cluster of Paenibacillus popilliae. Antimicrob Agents Chemother 2005; 49:2625-33. [PMID: 15980329 PMCID: PMC1168687 DOI: 10.1128/aac.49.7.2625-2633.2005] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Paenibacillus popilliae contains vanF encoding a putative D-Ala:D-lactate (D-Lac) ligase, VanF, as part of the vanY(F)Z(F)H(F)FX(F) cluster that is similar in structure to the enterococcal vanA and vanB clusters. Using growth curves, we demonstrated that vancomycin resistance in P. popilliae is inducible. Using degenerate oligonucleotides targeted at bacterial cell wall ligases, we identified a second ligase gene with features of a D-Ala:D-Ala ligase in both P. popilliae and the related, vancomycin-susceptible, Paenibacillus lentimorbus. The 3,380-bp region upstream of vanY(F)Z(F)H(F)FX(F) in P. popilliae ATCC 14706 was sequenced and found to contain genes encoding a putative two-component regulator, VanR(F)S(F), similar to VanRS but more closely related to a family of two-component regulators linked to VanY-like carboxypeptidases in several glycopeptide-susceptible Bacillus species. This upstream region also included a transposase similar to a transposase found in Bacillus halodurans and, in some strains, a 99-bp insertion of unknown function with 95% nucleotide identity to a portion of the Tn1546 transposase gene. Analysis of glycopeptide resistance-associated clusters from soil and/or insect-dwelling organisms may provide important clues to the molecular evolution of acquired glycopeptide resistance elements in human pathogens.
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Affiliation(s)
- Henry Fraimow
- Division of Infectious Diseases, Cooper Health System and University of Medicine and Dentistry of New Jersey, 401 Haddon Avenue, Room 274, Camden, New Jersey 08103, USA.
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Perreten V, Vorlet-Fawer L, Slickers P, Ehricht R, Kuhnert P, Frey J. Microarray-based detection of 90 antibiotic resistance genes of gram-positive bacteria. J Clin Microbiol 2005; 43:2291-302. [PMID: 15872258 PMCID: PMC1153730 DOI: 10.1128/jcm.43.5.2291-2302.2005] [Citation(s) in RCA: 219] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A disposable microarray was developed for detection of up to 90 antibiotic resistance genes in gram-positive bacteria by hybridization. Each antibiotic resistance gene is represented by two specific oligonucleotides chosen from consensus sequences of gene families, except for nine genes for which only one specific oligonucleotide could be developed. A total of 137 oligonucleotides (26 to 33 nucleotides in length with similar physicochemical parameters) were spotted onto the microarray. The microarrays (ArrayTubes) were hybridized with 36 strains carrying specific antibiotic resistance genes that allowed testing of the sensitivity and specificity of 125 oligonucleotides. Among these were well-characterized multidrug-resistant strains of Enterococcus faecalis, Enterococcus faecium, and Lactococcus lactis and an avirulent strain of Bacillus anthracis harboring the broad-host-range resistance plasmid pRE25. Analysis of two multidrug-resistant field strains allowed the detection of 12 different antibiotic resistance genes in a Staphylococcus haemolyticus strain isolated from mastitis milk and 6 resistance genes in a Clostridium perfringens strain isolated from a calf. In both cases, the microarray genotyping corresponded to the phenotype of the strains. The ArrayTube platform presents the advantage of rapidly screening bacteria for the presence of antibiotic resistance genes known in gram-positive bacteria. This technology has a large potential for applications in basic research, food safety, and surveillance programs for antimicrobial resistance.
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Affiliation(s)
- Vincent Perreten
- Institute of Veterinary Bacteriology, University of Berne, Längass-Strasse 122, Postfach, CH-3001 Bern, Switzerland.
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Abriouel H, Lucas R, Ben Omar N, Valdivia E, Maqueda M, Martínez-Cañamero M, Gálvez A. Enterocin AS-48RJ: a variant of enterocin AS-48 chromosomally encoded by Enterococcus faecium RJ16 isolated from food. Syst Appl Microbiol 2005; 28:383-97. [PMID: 16094865 DOI: 10.1016/j.syapm.2005.01.007] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The bacteriocinogenic strain RJ16 isolated from goat cheese has been identified as Enterococcusfaecium by species-specific PCR, DNA-rRNA hybridization and rDNA sequencing. Purified bacteriocin from strain RJ16 is a carboxypeptidase A-resistant peptide with a molecular mass (7125 Da) very close to the cyclic peptide enterocin AS-48. Bacteriocin from strain RJ16 and AS-48 show identical antibacterial spectra, although the former is slightly less active on strains of Listeria monocytogenes and Bacillus cereus. Producer strains show cross-immunity. PCR amplification of total DNA from strain RJ16 with primers for the AS-48 structural gene and sequencing of the amplified fragment revealed an almost identical sequence (99.5%), except for a single mutation that predicts the change of Glu residue at position 20 of AS-48 to Val. Therefore, bacteriocin produced by E. faecium RJ16 should be considered a variant of AS-48, which we call AS-48RJ. PCR amplification revealed that strain RJ16 contains the complete as-48. gene cluster. Hybridization with probes for as-48 gene cluster revealed a chromosomal location of as-48 genes in strain RJ16, being the first example of a chromosomal location of this bacteriocin trait. Strain RJ16 produced enzymes of interest in food processing (esterase, esterase lipase and phytase activities), and did not decarboxylate amino acids precursors for biogenic amines. Strain RJ16 did not exhibit haemolytic or gelatinase activities, and PCR amplification revealed the lack of genes encoding for known virulence determinants (aggregation substance, collagen adhesin, enterococcal surface protein, endocarditis antigens, as well as haemolysin and gelatinase production). Strain RJ16 was resistant to ciprofloxacin (MIC > 2 mgl(-1)) and levofloxacin (MIC > 4 mgl(-1)) and showed intermediate resistance to nitrofurantoin and erythromycin, but was sensitive to ampicillin, penicillin, streptomycin, gentamicin, rifampicin, chloramphenicol, tetracycline, quinupristin/dalfopristin, vancomycin and teicoplanin. Altogether, results from this study suggest that this broad-spectrum bacteriocin-producing strain may have a potential use in food preservation.
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Affiliation(s)
- Hikmate Abriouel
- Area de Microbiología, Departamento de Ciencias de la Salud, Facultad de Ciencias Experimentales, Universidad de Jaén, 23071-Jaén, Spain
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Panesso D, Abadía-Patiño L, Vanegas N, Reynolds PE, Courvalin P, Arias CA. Transcriptional analysis of the vanC cluster from Enterococcus gallinarum strains with constitutive and inducible vancomycin resistance. Antimicrob Agents Chemother 2005; 49:1060-6. [PMID: 15728903 PMCID: PMC549275 DOI: 10.1128/aac.49.3.1060-1066.2005] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The vanC glycopeptide resistance gene cluster encodes enzymes required for synthesis of peptidoglycan precursors ending in D-Ala-D-Ser. Enterococcus gallinarum BM4174 and SC1 are constitutively and inducibly resistant to vancomycin, respectively. Analysis of peptidoglycan precursors in both strains indicated that UDP-MurNAc-tetrapeptide and UDP-MurNAc-pentapeptide[D-Ser] were synthesized in E. gallinarum SC1 only in the presence of vancomycin (4 microg/ml), whereas the "resistance" precursors accumulated in the cytoplasm of BM4174 cells under both inducing and noninducing conditions. Northern hybridization and reverse transcription-PCR experiments revealed that all the genes from the cluster, vanC-1, vanXY(C), vanT, vanR(C), and vanS(C), were transcribed from a single promoter. In the inducible SC1 isolate, transcriptional regulation appeared to be responsible for inducible expression of resistance. Promoter mapping in E. gallinarum BM4174 revealed that the transcriptional start site was located 30 nucleotides upstream from vanC-1 and that the -10 promoter consensus sequence had high identity with that of the vanA cluster. Comparison of the deduced sequence of the vanS(C) genes from isolates with constitutive and inducible resistance revealed several amino acid substitutions located in the X box (R200L) and in the region between the F and G2 boxes (D312N, D312A, and G320S) of the putative sensor kinase proteins from isolates with constitutive resistance.
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Affiliation(s)
- Diana Panesso
- Bacterial Molecular Genetics Unit, Centro de Investigaciones, Universidad El Bosque, Bogotá, Columbia
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31
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Seo KS, Lim JY, Yoo HS, Bae WK, Park YH. Comparison of vancomycin-resistant enterococci isolates from human, poultry and pigs in Korea. Vet Microbiol 2005; 106:225-33. [PMID: 15778028 DOI: 10.1016/j.vetmic.2004.11.017] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2003] [Revised: 11/12/2004] [Accepted: 11/23/2004] [Indexed: 11/23/2022]
Abstract
Vancomycin-resistant enterococci (VRE) have emerged as an important nosocomial pathogen. Since 1989, a rapid increase in the incidence of enterococcal bacteremia and endocarditis by VRE has been reported. The use of avoparcin in animal husbandry is reportedly associated with the appearance of VRE. In this study, a multiplex polymerase chain reaction (PCR) method was established to detect and differentiate resistant types of enterococci, which specifically amplify the four van genes that encode vancomycin resistance elements. Using this method, we investigated the incidence rates and types of VRE from two types of farms: those that had used avoparcin and those that had not used avoparcin. A total of 1091 animal fecal samples were collected from 70 pig farms and 32 poultry farms. A total of 425 enterococci were isolated from the fecal samples. Among the 425 isolates, six showed a pattern of high-level vancomycin resistance (Minimal Inhibitory Concentration, MIC: 64-256 microg/ml). Out of six high-level VRE, three were isolated from poultry farms that had used avoparcin and three were not. The six high-level VRE harbored the vanA gene. Sixty-seven of 425 isolates that showed a pattern of low-level vancomycin resistance (MIC: 4-8 microg/ml) were associated with the presence of vanC-1 or vanC-2/3 gene. We also performed a repetitive extragenic palindromic PCR (rep-PCR) method to compare the genetic relatedness between the high-level VRE of six animal isolates and 31 human isolates. None of the animal isolates had a similar rep-PCR pattern as the human isolates but similarities between human VRE isolates were observed.
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Affiliation(s)
- Keun Seok Seo
- Department of Microbiology, Molecular Biology and Biochemistry, College of Agriculture, University of Idaho, Moscow, ID 83844, USA
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32
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Reynolds PE, Courvalin P. Vancomycin resistance in enterococci due to synthesis of precursors terminating in D-alanyl-D-serine. Antimicrob Agents Chemother 2005; 49:21-5. [PMID: 15616270 PMCID: PMC538887 DOI: 10.1128/aac.49.1.21-25.2005] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Peter E Reynolds
- Department of Biochemistry, University of Cambridge, Tennis Court Rd., Cambridge CB2 1QW, United Kingdom.
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Depardieu F, Perichon B, Courvalin P. Detection of the van alphabet and identification of enterococci and staphylococci at the species level by multiplex PCR. J Clin Microbiol 2004; 42:5857-60. [PMID: 15583325 PMCID: PMC535300 DOI: 10.1128/jcm.42.12.5857-5860.2004] [Citation(s) in RCA: 201] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2004] [Accepted: 08/23/2004] [Indexed: 11/20/2022] Open
Abstract
A multiplex PCR assay was developed for detection of the six types of glycopeptide resistance characterized in enterococci and for identification of Enterococcus faecium, Enterococcus faecalis, Staphylococcus aureus, and Staphylococcus epidermidis at the species level. Primers targeting the genes vanA, vanB, vanC, vanD, vanE, vanG, and ddl of E. faecium and E. faecalis and nuc of S. aureus and a chromosomal portion specific to S. epidermidis were designed to allow amplification of fragments with various sizes. This specific and sensitive technique allows detection of glycopeptide-resistant strains, in particular methicillin-resistant S. aureus, that may escape phenotype-based automated rapid methods.
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Affiliation(s)
- Florence Depardieu
- Unité des Agents Antibactériens, Institut Pasteur, 25, rue du Docteur Roux, 75724 Paris Cedex 15, France
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34
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Noda M, Kawahara Y, Ichikawa A, Matoba Y, Matsuo H, Lee DG, Kumagai T, Sugiyama M. Self-protection Mechanism in d-Cycloserine-producing Streptomyces lavendulae. J Biol Chem 2004; 279:46143-52. [PMID: 15302885 DOI: 10.1074/jbc.m404603200] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
An antibiotic, D-cycloserine (DCS), inhibits the catalytic activities of alanine racemase (ALR) and d-alanyl-d-alanine ligase (DDL), which are necessary for the biosynthesis of the bacterial cell wall. In this study, we cloned both genes encoding ALR and DDL, designated alrS and ddlS, respectively, from DCS-producing Streptomyces lavendulae ATCC25233. Each gene product was purified to homogeneity and characterized. Escherichia coli, transformed with a pET vector carrying alrS or ddlS, displays higher resistance to DCS than the same host carrying the E. coli ALR- or DDL-encoded gene inserted into the pET vector. Although the S. lavendulae DDL was competitively inhibited by DCS, the K(i) value (920 microM) was obviously higher (40 approximately 100-fold) than those for E. coli DdlA (9 microM) or DdlB (27 microM). The high K(i) value of the S. lavendulae DDL suggests that the enzyme may be a self-resistance determinant in the DCS-producing microorganism. Kinetic studies for the S. lavendulae ALR suggest that the time-dependent inactivation rate of the enzyme by DCS is absolutely slower than that of the E. coli ALR. We conclude that ALR from DCS-producing S. lavendulae is also one of the self-resistance determinants.
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Affiliation(s)
- Masafumi Noda
- Department of Molecular Microbiology and Biotechnology, Graduate School of Biomedical Sciences, Hiroshima University, Kasumi 1-2-3, Minami-Ku, Hiroshima 734-8551, Japan
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35
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David V, Bozdogan B, Mainardi JL, Legrand R, Gutmann L, Leclercq R. Mechanism of intrinsic resistance to vancomycin in Clostridium innocuum NCIB 10674. J Bacteriol 2004; 186:3415-22. [PMID: 15150227 PMCID: PMC415764 DOI: 10.1128/jb.186.11.3415-3422.2004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We have studied the basis for intrinsic resistance to low levels of vancomycin in Clostridium innocuum NCIB 10674 (MIC = 8 microg/ml). Analysis by high-pressure liquid chromatography (HPLC) and mass spectrometry of peptidoglycan nucleotide precursors pools revealed the presence of two types of UDP-MurNac-pentapeptide precursors constitutively produced, an UDP-MurNAc-pentapeptide with a serine at the C terminus which represented 93% of the pool and an UDP-MurNAc-pentapeptide with an alanine at the C terminus which represented the rest of the pool. C. innocuum cell wall muropeptides containing pentapeptide[Ser], either dialanine substituted on the epsilon amino group of lysine or not, were identified and represented about 10% of the monomers while only 1% of pentapeptide[D-Ala] monomers were found. The sequence of a 2,465-bp chromosomal fragment from C. innocuum was determined and revealed the presence of ddl(c. innocuum) and C. innocuum racemase genes putatively encoding homologues of D-Ala:D-X ligases and amino acid racemases, respectively. Analysis of the pool of precursors of Enterococcus faecalis JH2-2, containing cloned ddl(c. innocuum) and C. innocuum racemase genes showed in addition to the UDP-MurNAc-pentapeptide[D-Ala], the presence of an UDP-MurNAc-pentapeptide[D-Ser] precursor. However, the expression of low-level resistance to vancomycin was observed only when both genes were cloned in E. faecalis JH2-2 together with the vanXYc gene from Enterococcus gallinarum BM4174 which encodes a d,d-peptidase which eliminates preferentially the high affinity vancomycin UDP-MurNAc-pentapeptide [D-Ala] precursors produced by the host. We conclude that resistance to vancomycin in C. innocuum NCIB 10674 was related to the presence of the two chromosomal ddl(c. innocuum) and C. innocuum racemase genes allowing the synthesis of a peptidoglycan precursor terminating in serine with low affinity for vancomycin.
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Affiliation(s)
- Véronique David
- Service de Bactériologie-Virologie, Hôpital Henri Mondor-Université Paris XII, Crétil, France
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Hanaki H, Yamaguchi Y, Nomura S, Nagayama A, Sunakawa K. Rapid detection and differentiation method of VanA, VanB and VanC phenotypes in vancomycin-resistant enterococci. Int J Antimicrob Agents 2004; 23:502-5. [PMID: 15120731 DOI: 10.1016/j.ijantimicag.2003.09.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2003] [Accepted: 09/22/2003] [Indexed: 11/22/2022]
Abstract
We developed a simple method that can replace the polymerase chain reaction (PCR) to distinguish between vancomycin-resistant enterococci (VRE) with the vanA, vanB and vanC genes. The method is based on induction of teicoplanin resistance by vancomycin in vanB-VRE, while the two compounds have a synergistic effect in vanC-VRE. In addition, vanA-VRE shows resistance to both vancomycin and teicoplanin, and both the compounds can induce resistance to vanA-VRE. Utilising these properties, we attempted to develop a simple method to distinguish between vanA, vanB and vanC. We compared our simple method with the PCR method in 43 strains of vanA-VRE, 35 strains of vanB-VRE and 37 strains of vanC-VRE. The results were 100% consistent with that obtained by PCR.
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Affiliation(s)
- Hideaki Hanaki
- Laboratory of Clinical Bacteriology, Department Nutrition Nakamuragakuen University, 5-7-1 Befu, Jyonan-ku, Fukuoka, Japan.
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37
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Jorgensen JH, Crawford SA, Kelly CC, Patterson JE. In vitro activity of daptomycin against vancomycin-resistant enterococci of various Van types and comparison of susceptibility testing methods. Antimicrob Agents Chemother 2004; 47:3760-3. [PMID: 14638478 PMCID: PMC296189 DOI: 10.1128/aac.47.12.3760-3763.2003] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The increasing prevalence of vancomycin-resistant enterococcal (VRE) infections and the limited number of antimicrobial agents for their treatment emphasize a need for new, more effective agents. In this study, the in vitro activity of daptomycin was determined against a collection of 156 VRE from seven different institutions. Van types were characterized by PCR, and pulsed-field gel electrophoresis was performed to exclude isolates with >85% relatedness by dendrogram. Included were 126 Enterococcus faecium (109 vanA, 17 vanB) isolates, 5 Enterococcus faecalis (3 vanA, 2 vanB) isolates, 2 Enterococcus avium (vanA) isolates, 1 Enterococcus durans (vanA) isolate, 10 Enterococcus gallinarum (vanC1) isolates, and 12 Enterococcus casseliflavus (vanC2) isolates. MICs of daptomycin and five additional agents were determined by the NCCLS broth microdilution method with Mueller-Hinton (MH) broth containing supplemental calcium. MICs were also determined using two investigational E-test strip formulations, and disk diffusion testing was performed by the standard NCCLS method. The MIC of daptomycin at which 50% of the isolates tested were inhibited for this isolate collection was 4 microg/ml, and the MIC at which 90% of the isolates tested were inhibited was 8 microg/ml. Two isolates of vanA E. faecium were resistant to linezolid, and one isolate was resistant to quinupristin-dalfopristin. MICs of daptomycin determined by the E test with and without added calcium varied by 8- to 16-fold, and disk diffusion zones varied by 3 to 6 mm according to the calcium content of the commercial MH agar lots used in the study. This study has shown daptomycin to have good activity against a diverse collection of contemporary VRE isolates. However, improved standardization of the calcium content of MH agar will be important for reliable testing of daptomycin by clinical laboratories using either the E test or disk diffusion methods.
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Affiliation(s)
- James H Jorgensen
- Department of Pathology, The University of Texas Health Science Center, San Antonio, Texas 78229, USA.
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38
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Feng Z, Barletta RG. Roles of Mycobacterium smegmatis D-alanine:D-alanine ligase and D-alanine racemase in the mechanisms of action of and resistance to the peptidoglycan inhibitor D-cycloserine. Antimicrob Agents Chemother 2003; 47:283-91. [PMID: 12499203 PMCID: PMC149019 DOI: 10.1128/aac.47.1.283-291.2003] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
D-Cycloserine (DCS) targets the peptidoglycan biosynthetic enzymes D-alanine racemase (Alr) and D-alanine:D-alanine ligase (Ddl). Previously, we demonstrated that the overproduction of Alr in Mycobacterium smegmatis determines a DCS resistance phenotype. In this study, we investigated the roles of both Alr and Ddl in the mechanisms of action of and resistance to DCS in M. smegmatis. We found that the overexpression of either the M. smegmatis or the Mycobacterium tuberculosis ddl gene in M. smegmatis confers resistance to DCS, but at lower levels than the overexpression of the alr gene. Furthermore, a strain overexpressing both the alr and ddl genes displayed an eightfold-higher level of resistance. To test the hypothesis that inhibition of Alr by DCS decreases the intracellular pool of D-alanine, we determined the alanine pools in M. smegmatis wild-type and recombinant strains with or without DCS treatment. Alr-overproducing strain GPM14 cells not exposed to DCS displayed almost equimolar amounts of L- and D-alanine in the steady state. The wild-type strain and Ddl-overproducing strains contained a twofold excess of L- over D-alanine. In all strains, DCS treatment led to a significant accumulation of L-alanine and a concomitant decease of D-alanine, with approximately a 20-fold excess of L-alanine in the Ddl-overproducing strains. These data suggest that Ddl is not significantly inhibited by DCS at concentrations that inhibit Alr. This study is of significance for the identification of the lethal target(s) of DCS and the development of novel drugs targeting the D-alanine branch of mycobacterial peptidoglycan biosynthesis.
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Affiliation(s)
- Zhengyu Feng
- Department of Veterinary and Biomedical Sciences, University of Nebraska, Lincoln, Nebraska 68583-0905, USA
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39
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Abadía Patiño L, Courvalin P, Perichon B. vanE gene cluster of vancomycin-resistant Enterococcus faecalis BM4405. J Bacteriol 2002; 184:6457-64. [PMID: 12426332 PMCID: PMC135418 DOI: 10.1128/jb.184.23.6457-6464.2002] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Acquired VanE-type resistance to low levels of vancomycin (MIC = 16 microg/ml) in Enterococcus faecalis BM4405 is due to the inducible synthesis of peptidoglyean precursors terminating in D-alanine-D-serine (Fines,M., B. Prichon, P. Reynolds, D. Sahm, and P. Courvalin, Antimicrob. Agents Chemother. 43:2161-2164, 1999). A chromosomal location was assigned to the vanE operon by pulsed-field gel electrophoresis and hybridization, and its sequence was determined. Three genes, encoding the VanE ligase, the VanXYE DD-peptidase, and the VanTE serine racemase, that displayed 43 to 53% identity with the corresponding genes in the vanC operon were found. In addition, two genes coding for a two-component regulatory system, VanRE-VanSE, exhibiting 60 and 44% identity with VanR,-VanS, were present downstream from vanTE. However, because of a stop codon at position 78, VanSE was probably not functional. The five genes, with the same orientation, were shown to be cotranscribed by Northern analysis and reverse transcription-PCR. The vanE, vanXYE, and vanTE genes conferred inducible low-level resistance to vancomycin after cloning in E. faecalis JH2-2, probably following cross talk with a two-component regulatory system of the host.
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40
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Dutta I, Reynolds PE. Biochemical and genetic characterization of the vanC-2 vancomycin resistance gene cluster of Enterococcus casseliflavus ATCC 25788. Antimicrob Agents Chemother 2002; 46:3125-32. [PMID: 12234834 PMCID: PMC128795 DOI: 10.1128/aac.46.10.3125-3132.2002] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The vanC-2 cluster of Enterococcus casseliflavus ATCC 25788 consisted of five genes (vanC-2, vanXY(C-2), vanT(C-2), vanR(C-2), and vanS(C-2)) and shared the same organization as the vanC cluster of E. gallinarum BM4174. The proteins encoded by these genes displayed a high degree of amino acid identity to the proteins encoded within the vanC gene cluster. The putative D,D-dipeptidase-D,D-carboxypeptidase, VanXY(C-2), exhibited 81% amino acid identity to VanXY(C), and VanT(C-2) displayed 65% amino acid identity to the serine racemase, VanT. VanR(C-2) and VanS(C-2) displayed high degrees of identity to VanR(C) and VanS(C), respectively, and contained the conserved residues identified as important to their function as a response regulator and histidine kinase, respectively. Resistance to vancomycin was expressed inducibly in E. casseliflavus ATCC 25788 and required an extended period of induction. Analysis of peptidoglycan precursors revealed that UDP-N-acetylmuramyl-L-Ala-delta-D-Glu-L-Lys-D-Ala-D-Ser could not be detected until several hours after the addition of vancomycin, and its appearance coincided with the resumption of growth. The introduction of additional copies of the vanT(C-2) gene, encoding a putative serine racemase, and the presence of supplementary D-serine in the growth medium both significantly reduced the period before growth resumed after addition of vancomycin. This suggested that the availability of D-serine plays an important role in the induction process.
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Affiliation(s)
- Ireena Dutta
- Department of Biochemistry, University of Cambridge, United Kingdom CB2 1QW
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41
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Podmore AHB, Reynolds PE. Purification and characterization of VanXY(C), a D,D-dipeptidase/D,D-carboxypeptidase in vancomycin-resistant Enterococcus gallinarum BM4174. EUROPEAN JOURNAL OF BIOCHEMISTRY 2002; 269:2740-6. [PMID: 12047383 DOI: 10.1046/j.1432-1033.2002.02946.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
VanXY(C), a bifunctional enzyme from VanC-phenotype Enterococcus gallinarum BM4174 that catalyses D,D-peptidase and D,D-carboxypeptidase activities, was purified as the native protein, as a maltose-binding protein fusion and with an N-terminal tag containing six histidine residues. The kinetic parameters of His(6)-VanXY(C) were measured for a variety of precursors of peptidoglycan synthesis involved in resistance: for D-Ala-D-Ala, the K(m) was 3.6 mm and k(cat), 2.5 s(-1); for UDP-MurNAc-L-Ala-D-Glu-L-Lys-DAla-D-Ala (UDP-MurNAc-pentapeptide[Ala]), K(m) was 18.8 mm and k(cat) 6.2 s(-1); for D-Ala-D-Ser, K(m) was 15.5 mm and k(cat) 0.35 s(-1). His(6)-VanXYC was inactive against the peptidoglycan precursor UDP-MurNAc-L-Ala-D-Glu-L-Lys-D-Ala-D-Ser (UDP-MurNAc-pentapeptide[Ser]). The rate of hydrolysis of the terminal D-Ala of UDP-MurNAc-pentapeptide[Ala] was inhibited 30% by 2 mm D-Ala-D-Ser or UDP-MurNAc-pentapeptide[Ser]. Therefore preferential hydrolysis of substrates terminating in D-Ala would occur during peptidoglycan synthesis in E. gallinarum BM4174, leaving precursors ending in D-Ser with a lower affinity for glycopeptides to be incorporated into peptidoglycan. Mutation of an aspartate residue (Asp59) of His-tagged VanXY(C) corresponding to Asp68 in VanX to Ser or Ala, resulted in a 50% increase and 73% decrease, respectively, of the specificity constant (k(cat)/K(m)) for D-Ala-D-Ala. This situation is in contrast to VanX in which mutation of Asp68-->Ala produced a greater than 200,000-fold decrease in the substrate specificity constant. This suggests that Asp59, unlike Asp68 in VanX, does not have a pivotal role in catalysis.
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Boyd DA, Cabral T, Van Caeseele P, Wylie J, Mulvey MR. Molecular characterization of the vanE gene cluster in vancomycin-resistant Enterococcus faecalis N00-410 isolated in Canada. Antimicrob Agents Chemother 2002; 46:1977-9. [PMID: 12019119 PMCID: PMC127252 DOI: 10.1128/aac.46.6.1977-1979.2002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The vanE operon was characterized from Enterococcus faecalis N00-410 (MIC of vancomycin = 24 microg/ml). The organization of the vanE operon was identical to that of the vanC1 operon from Enterococcus gallinarum, with protein identities ranging from 46 to 63%. An open reading frame located downstream of the vanE operon showed significant homology to a number of integrase genes, all of which are located downstream of the chromosomal GMP synthase gene guaA.
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Affiliation(s)
- D A Boyd
- Nosocomial Infections, National Microbiology Laboratory, Health Canada, Winnipeg, Manitoba, Canada
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43
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Abstract
Glycopeptide antibiotics are integral components of the current antibiotic arsenal that is under strong pressures as a result of the emergence of a variety of resistance mechanisms over the past 15 years. Resistance has manifested itself largely through the expression of genes that encode proteins that reprogram cell wall biosynthesis and thus evade the action of the antibiotic in the enterococci, though recently new mechanisms have appeared that afford resistance and tolerance in the more virulent staphylococci and streptococci. Overcoming glycopeptide resistance will require innovative approaches to generate new antibiotics or otherwise to inhibit the action of resistance elements in various bacteria. The chemical complexity of the glycopeptides, the challenges of discovering and successfully exploiting new targets, and the growing number of distinct resistance types all increase the difficulty of the current problem we face as a result of the emergence of glycopeptide resistance.
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Affiliation(s)
- Jeff Pootoolal
- Antimicrobial Research Centre, Department of Biochemistry, McMaster University, Hamilton, Ontario, Canada.
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Jones ME, Gesu G, Ortisi G, Sahm DF, Critchley IA, Goglio A. Proficiency of Italian clinical laboratories in detecting reduced glycopeptide susceptibility in Enterococcus and Staphylococcus spp. using routine laboratory methodologies. Clin Microbiol Infect 2002; 8:101-11. [PMID: 11952723 DOI: 10.1046/j.1469-0691.2002.00378.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To assess the ability of 59 clinical microbiology laboratories distributed throughout Italy to correctly identify and detect reduced susceptibility to glycopeptides in staphylococci and VanA-, VanB- or VanC-mediated glycopeptide resistance in enterococci. METHODS Eight test strains comprising three staphylococci (S. aureus ATCC 29212 and two vancomycin-intermediate S. haemolyticus [11105301, 10030683Y]) and five enterococci (E. faecalis ATCC 29212, E. faecalis ATCC 51299 VanB, E. faecium AIB40 VanA, E. faecalis V583 VanB and E. gallinarum AIB39 VanC1) were distributed to 59 Italian clinical microbiology laboratories. Each isolate was blind-coded, and laboratories were instructed to identify the strains and test isolates for susceptibility to teicoplanin and vancomycin using their standard methods. Results were assessed against consensus test results obtained by a reference laboratory. In addition, to complement data interpretation, laboratories were asked to provide retrospective routine test results from their respective hospitals. RESULTS All 59 laboratories participating in the study completed the susceptibility testing and provided data for analysis. A total of 53 laboratories provided retrospective routine data. Overall, laboratories were able to identify isolates to the genus level successfully. E. gallinarum and S. haemolyticus posed problems for species identification, with only 40.6 and 71.2%, respectively, of results reported correctly; most incorrect results were reported as 'other species'. For enterococcal test strains, VanA phenotypes were detected correctly by 96.6% of laboratories; VanB by 30.5% (E. faecalis ATCC 51299) and 88.1% (E. faecalis V583); and VanC1 by 67.8%. For staphylococcal test strains, 28.8% (S. haemolyticus 11105301) and 23.7% (S. haemolyticus 10030683Y) of the laboratories were able to detect reduced susceptibility to vancomycin. Errors in detecting vancomycin resistance in VanB and VanC1 enterococci were made with all methods, most noticeably by disk diffusion users. For staphylococci, most errors in reporting vancomycin-intermediate resistance occurred with disk diffusion and Vitek (software version 5.04) users. Overall, considerably fewer errors occurred with the detection of teicoplanin resistance, especially for staphylococci. For 1999, routine results show that 41/1749 (2.4%) of E. faecium, 220/11 180 (2.0%) of E. faecalis, 29/24 927 (0.12%) of S. aureus and 54/22 102 (0.24%) of coagulase-negative staphylococci were reported as resistant to vancomycin. CONCLUSION Italian laboratories are able to identify staphylococci and enterococci adequately, although all methodologies used have problems in identifying E. gallinarum and coagulase-negative staphylococci to the species level. While VanA phenotypes were efficiently detected, problems were experienced in detecting VanB and VanC phenotypes. The majority of laboratories were unable to detect reduced vancomycin susceptibility in staphylococci adequately, especially with disk diffusion and older Vitek systems. Teicoplanin appeared useful as a marker for detecting vancomycin resistance, particularly with disk diffusion. Should enterococcal VanB or staphylococcal glycopeptide-intermediate phenotypes become prevalent in Italy, it is likely that they would be under-detected. New systems under development, such as Vitek2, should improve this situation.
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Affiliation(s)
- M E Jones
- Focus Technologies Inc., Hilversum, The Netherlands.
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45
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Ambúr OH, Reynolds PE, Arias CA. D-Ala:D-Ala ligase gene flanking the vanC cluster: evidence for presence of three ligase genes in vancomycin-resistant Enterococcus gallinarum BM4174. Antimicrob Agents Chemother 2002; 46:95-100. [PMID: 11751117 PMCID: PMC126995 DOI: 10.1128/aac.46.1.95-100.2002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
An open reading frame located 230 nucleotides downstream from the stop codon of vanS(c) and in the opposite direction relative to the other genes of the vanC cluster was identified in Enterococcus gallinarum BM4174. This gene (designated ddl2) encoded a protein of 343 amino acids that had significant predicted structural similarity to D-Ala:D-Ala ligases and displayed 33 and 35% amino acid identity to VanC-1 and the previously reported partial sequence of Ddl from E. gallinarum, respectively. Biochemical characterization by thin-layer chromatography confirmed that Ddl2 is a D-Ala:D-Ala ligase with no detectable D-Ala:D-Ser ligase activity. The vancomycin dependence of Enterococcus faecalis BM4320 (ddl mutant) was lost on electroporation of a plasmid construct expressing ddl2 constitutively. The latter strain was able to grow in the absence of vancomycin, and peptidoglycan precursor analysis under the same conditions indicated the synthesis of pentapeptide[D-Ala] as the main precursor, confirming the activity of Ddl2 in vivo. Expression of ddl and ddl2 in BM4174 was tested by reverse transcription-PCR: results suggested that both D-Ala:D-Ala ligases were expressed concomitantly. Our findings indicate that vancomycin-resistant E. gallinarum BM4174 is likely to express one D-Ala:D-Ser and two D-Ala:D-Ala ligase genes.
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Affiliation(s)
- Ole-Herman Ambúr
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
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46
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Harwood VJ, Brownell M, Perusek W, Whitlock JE. Vancomycin-resistant Enterococcus spp. isolated from wastewater and chicken feces in the United States. Appl Environ Microbiol 2001; 67:4930-3. [PMID: 11571206 PMCID: PMC93253 DOI: 10.1128/aem.67.10.4930-4933.2001] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Vancomycin-resistant Enterococcus spp. (VRE) were isolated from sewage and chicken feces but not from other animal fecal sources (dog, cow, and pig) or from surface waters tested. VRE from hospital wastewater were resistant to > or =20 microg of vancomycin/ml and possessed the vanA gene. VRE from residential wastewater and chicken feces were resistant to 3 to 5 microg of vancomycin/ml and possessed the vanC gene.
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Affiliation(s)
- V J Harwood
- Department of Biology, University of South Florida, Tampa 33620, USA.
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47
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Aráoz R, Anhalt E, René L, Badet-Denisot MA, Courvalin P, Badet B. Mechanism-based inactivation of VanX, a D-alanyl-D-alanine dipeptidase necessary for vancomycin resistance. Biochemistry 2000; 39:15971-9. [PMID: 11123924 DOI: 10.1021/bi001408b] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
VanX is a zinc-dependent D-Ala-D-Ala amino dipeptidase required for high-level resistance to vancomycin. The enzyme is also able to process dipeptides with bulky C-terminal amino acids [Wu, Z., Wright, G. D., and Walsh, C. T. (1995) Biochemistry 34, 2455-2463]. We took advantage of this observation to design and synthesize the dipeptide-like D-Ala-D-Gly(SPhip-CHF(2))-OH (7) as a potential mechanism-based inhibitor. VanX-mediated peptide cleavage generates a highly reactive 4-thioquinone fluoromethide which is able to covalently react with enzyme nucleophilic residues, resulting in irreversible inhibition. Inhibition of VanX by 7 was time-dependent (K(irr) = 30+/-1 microM; k(inact) = 7.3+/- 0.3 min(-1)) and active site-directed, as deduced from substrate protection experiments. Nucleophilic compounds such as sodium azide, potassium cyanide, and glutathione did not protect the enzyme from inhibition, indicating that the generated nucleophile inactivates VanX before leaving the active site. The failure to reactivate the dead enzyme by gel filtration or pH modification confirmed the covalent nature of the reaction that leads to inactivation. Inactivation was associated with the elimination of fluoride ion as deduced from (19)F NMR spectroscopy analysis and with the production of fluorinated thiophenol dimer 12. These data are consistent with suicide inactivation of VanX by dipeptide 7. The small size of the VanX active site and the presence of a number of nucleophilic side chains at the opening of the active site gorge [Bussiere, D. E., et al. (1998) Mol. Cell 2, 75-84] associated with the high observed partition ratio of 7500+/-500 suggest that the inhibitor is likely to react at the entrance of the active site cavity.
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Affiliation(s)
- R Aráoz
- Institut de Chimie des Substances Naturelles, CNRS-UPR2301, 91198 Gif-sur-Yvette, and Unité des Agents Antibactériens, Institut Pasteur, 75724 Paris Cedex 15, France
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48
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Abstract
Gram-positive cocci still predominate as a cause of nosocomial- and community-acquired infections. These organisms frequently reveal a high natural, intrinsic resistance to antimicrobials. Additionally, these bacteria are able to acquire resistance to frequently used drugs rapidly through selective pressure of the environment and via the genetic evolution of bacteria. The wide application of antimicrobials in medical and veterinary practice, usage of antibiotics in agriculture and common usage of antiseptics and disinfectants result in selective pressure. The use of antibiotics directly selects resistant variants to different antibiotics or disinfectants. The same genetic element (e.g. qac or smr) conferring resistance to some disinfectants are often present on the same plasmid conferring resistance to antibiotics. Selection of resistant variants occurs most frequently in the hospital environment. Staphylococcus aureus and enterococci are the most commonly isolated bacteria causing nosocomial infections. Among those giving therapeutic problems are methicillin-resistant staphylococci and vancomycin-resistant enterococci. Resistance to high levels of aminoglycosides or penicillins among hospital enterococcal strains can completely abolish synergism of the drugs. In these cases glycopeptides will be the drugs of choice in the treatment of serious infections. Recently S. aureus strains with decreased susceptibility to vancomycin has appeared. A mechanism for this elevated resistance, although intensively investigated, still remains unknown.
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Affiliation(s)
- J Jeljaszewicz
- National Institute of Hygiene, Medical University of Warsaw, 24 Chocimska, 00-791 Warsaw, Poland
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49
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McKessar SJ, Berry AM, Bell JM, Turnidge JD, Paton JC. Genetic characterization of vanG, a novel vancomycin resistance locus of Enterococcus faecalis. Antimicrob Agents Chemother 2000; 44:3224-8. [PMID: 11036060 PMCID: PMC101640 DOI: 10.1128/aac.44.11.3224-3228.2000] [Citation(s) in RCA: 116] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Enterococcus faecalis strain WCH9 displays a moderate level of resistance to vancomycin (MIC = 16 microgram/ml) and full susceptibility to teicoplanin but is negative by PCR analysis using primers specific for all known enterococcal vancomycin resistance genotypes (vanA, vanB, vanC, vanD, and vanE). We have isolated and sequenced a novel putative vancomycin resistance locus (designated vanG), which contains seven open reading frames, from this strain. These are organized differently from those of all the other enterococcal van loci, and, furthermore, the individual vanG gene products exhibit less than 50% amino acid sequence identity to other van gene products.
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Affiliation(s)
- S J McKessar
- Molecular Microbiology Unit, Women's and Children's Hospital, North Adelaide, South Australia 5006, Australia
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50
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Grohs P, Gutmann L, Legrand R, Schoot B, Mainardi JL. Vancomycin resistance is associated with serine-containing peptidoglycan in Enterococcus gallinarum. J Bacteriol 2000; 182:6228-32. [PMID: 11029446 PMCID: PMC94760 DOI: 10.1128/jb.182.21.6228-6232.2000] [Citation(s) in RCA: 37] [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
In Enterococcus gallinarum SC1, a low-level vancomycin-resistant strain, only monomeric muropentapeptides with a C-terminal D-alanine were detected after growth without vancomycin. In contrast, in SC1 induced by vancomycin, as well as in AIB39, a constitutive vancomycin-resistant strain, monomeric and dimeric muropentapeptides with a C-terminal D-serine were detected.
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Affiliation(s)
- P Grohs
- Laboratoire de Recherche Moléculaire sur les Antibiotiques, UFR Broussais-Hôtel Dieu, Université Paris VI, Paris, France
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