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Li G, Walker MJ, De Oliveira DMP. Vancomycin Resistance in Enterococcus and Staphylococcus aureus. Microorganisms 2022; 11:microorganisms11010024. [PMID: 36677316 PMCID: PMC9866002 DOI: 10.3390/microorganisms11010024] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 12/19/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022] Open
Abstract
Enterococcus faecalis, Enterococcus faecium and Staphylococcus aureus are both common commensals and major opportunistic human pathogens. In recent decades, these bacteria have acquired broad resistance to several major classes of antibiotics, including commonly employed glycopeptides. Exemplified by resistance to vancomycin, glycopeptide resistance is mediated through intrinsic gene mutations, and/or transferrable van resistance gene cassette-carrying mobile genetic elements. Here, this review will discuss the epidemiology of vancomycin-resistant Enterococcus and S. aureus in healthcare, community, and agricultural settings, explore vancomycin resistance in the context of van and non-van mediated resistance development and provide insights into alternative therapeutic approaches aimed at treating drug-resistant Enterococcus and S. aureus infections.
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Yoo SJ, Sung H, Cho YU, Kim MN, Pai CH, Kim YS. Role of Horizontal Transfer of the Transposon Tn1546in the Nosocomial Spread ofvanAVancomycin-Resistant Enterococci at a Tertiary Care Hospital in Korea. Infect Control Hosp Epidemiol 2016; 27:1081-7. [PMID: 17006816 DOI: 10.1086/507279] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2005] [Accepted: 01/30/2006] [Indexed: 11/04/2022]
Abstract
Objective:To investigate the epidemiologic characteristics of vancomycin-resistant enterococci (VRE) infection.Design.An epidemiologic description by means of chromosomal DNA fingerprinting and transposon typing.Setting.A 2,200-bed tertiary care hospital in Korea.Patients.First VRE isolates were obtained from patients hospitalized from April 1997 to December 2001.Interventions.Thevangenotypes of isolates were identified by means of multiplex polymerase chain reaction (PCR). The macro-restriction patterns of chromosomal DNA were determined by pulsed-field gel electrophoresis (PFGE). The transposon Tn1546was typed by means of 2 sets of long PCR restriction fragment-length polymorphism analysis, which wereClaI restriction of a 10.4-kb region fromorf1tovanZandDdeI restriction of a 4.4-kb region fromvanRtovanX.Results.VRE isolates were recovered from 215 patients. All werevanAgenotype. PFGE analysis of the 215 isolates showed 172 types, including 21 clusters composed of 64 isolates and 151 types of as many isolates. Each type was composed of 2-10 isolates; the isolates within each PFGE cluster were detected within a 10-month period and mostly shared a transposon type. Transposon typing classified 169 strains into 15 types and 158 strains belonged to 4 major transposon clusters. Each of these 4 transposon clusters was isolated from patients treated in 5-22 different wards during a 31-52 month period and consisted of 9-80 PFGE types. Each of the other 11 types were found in only one strain.Conclusions.Our findings suggest that the horizontal transfer of Tn1546has a major role in the nosocomial spread ofvanAVRE. Clonal spread of VRE seemed to contribute to short-term dissemination in limited areas.
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Affiliation(s)
- Soo Jin Yoo
- Department of Laboratory Medicine, University of Ulsan College of Medicine and Asan Medical Center, Seoul, Korea
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Freitas AR, Novais C, Tedim AP, Francia MV, Baquero F, Peixe L, Coque TM. Microevolutionary events involving narrow host plasmids influences local fixation of vancomycin-resistance in Enterococcus populations. PLoS One 2013; 8:e60589. [PMID: 23555993 PMCID: PMC3612099 DOI: 10.1371/journal.pone.0060589] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 02/28/2013] [Indexed: 12/28/2022] Open
Abstract
Vancomycin-resistance in enterococci (VRE) is associated with isolates within ST18, ST17, ST78 Enterococcus faecium (Efm) and ST6 Enterococcus faecalis (Efs) human adapted lineages. Despite of its global spread, vancomycin resistance rates in enterococcal populations greatly vary temporally and geographically. Portugal is one of the European countries where Tn1546 (vanA) is consistently found in a variety of environments. A comprehensive multi-hierarchical analysis of VRE isolates (75 Efm and 29 Efs) from Portuguese hospitals and aquatic surroundings (1996–2008) was performed to clarify the local dynamics of VRE. Clonal relatedness was established by PFGE and MLST while plasmid characterization comprised the analysis of known relaxases, rep initiator proteins and toxin-antitoxin systems (TA) by PCR-based typing schemes, RFLP comparison, hybridization and sequencing. Tn1546 variants were characterized by PCR overlapping/sequencing. Intra- and inter-hospital dissemination of Efm ST18, ST132 and ST280 and Efs ST6 clones, carrying rolling-circle (pEFNP1/pRI1) and theta-replicating (pCIZ2-like, Inc18, pHTβ-like, two pRUM-variants, pLG1-like, and pheromone-responsive) plasmids was documented. Tn1546 variants, mostly containing ISEf1 or IS1216, were located on plasmids (30–150 kb) with a high degree of mosaicism and heterogeneous RFLP patterns that seem to have resulted from the interplay between broad host Inc18 plasmids (pIP501, pRE25, pEF1), and narrow host RepA_N plasmids (pRUM, pAD1-like). TAs of Inc18 (ω-ε-ζ) and pRUM (Axe-Txe) plasmids were infrequently detected. Some plasmid chimeras were persistently recovered over years from different clonal lineages. This work represents the first multi-hierarchical analysis of VRE, revealing a frequent recombinatorial diversification of a limited number of interacting clonal backgrounds, plasmids and transposons at local scale. These interactions provide a continuous process of parapatric clonalization driving a full exploration of the local adaptive landscape, which might assure long-term maintenance of resistant clones and eventually fixation of Tn1546 in particular geographic areas.
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Affiliation(s)
- Ana R. Freitas
- REQUIMTE, Laboratório de Microbiologia, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
- Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
| | - Carla Novais
- REQUIMTE, Laboratório de Microbiologia, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
| | - Ana P. Tedim
- Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
- CIBER en Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
- Unidad de Resistencia a Antibióticos y Virulencia Bacteriana asociada al Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - María Victoria Francia
- Servicio de Microbiologia, Hospital Universitario Marqués de Valdecilla e Instituto de Formación e Investigación Marqués de Valdecilla (IFIMAV), Santander, Spain
| | - Fernando Baquero
- Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
- CIBER en Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
- Unidad de Resistencia a Antibióticos y Virulencia Bacteriana asociada al Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Luísa Peixe
- REQUIMTE, Laboratório de Microbiologia, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
| | - Teresa M. Coque
- Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
- CIBER en Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
- Unidad de Resistencia a Antibióticos y Virulencia Bacteriana asociada al Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
- * E-mail:
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Yoon YK, Sim HS, Kim JY, Park DW, Sohn JW, Roh KH, Lee SE, Kim MJ. Epidemiology and control of an outbreak of vancomycin-resistant enterococci in the intensive care units. Yonsei Med J 2009; 50:637-43. [PMID: 19881966 PMCID: PMC2768237 DOI: 10.3349/ymj.2009.50.5.637] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2008] [Revised: 01/06/2009] [Accepted: 01/06/2009] [Indexed: 11/27/2022] Open
Abstract
PURPOSE This study was aimed to describe a vancomycin-resistant enterococci (VRE) outbreak across three intensive care units (ICUs) of a Korean hospital from September 2006 to January 2007 and the subsequent control strategies. MATERIALS AND METHODS We simultaneously implemented multifaceted interventions to control the outbreak, including establishing a VRE cohort ward, active rectal surveillance cultures, daily extensive cleaning of environmental surfaces and environmental cultures, antibiotic restriction, and education of hospital staff. We measured weekly VRE prevalence and rectal acquisition rates and characterized the VRE isolates by polymerase chain reaction (PCR) of the vanA gene and Sma1-pulsed-field gel electrophoresis (PFGE). RESULTS During the outbreak, a total of 50 patients infected with VRE were identified by clinical and surveillance cultures, and 46 had vancomycin-resistant Enterococcus faecium (VREF). PFGE analysis of VREF isolates from initial two months disclosed 6 types and clusters of two major types. The outbreak was terminated 5 months after implementation of the interventions: The weekly prevalence rate decreased from 9.1/100 patients-day in September 2006 to 0.6/100 by the end of January 2007, and the rectal acquisition rates also dropped from 6.9/100 to 0/100 patients-day. CONCLUSION Our study suggests that an aggressive multifaceted control strategy is a rapid, effective approach for controlling a VRE outbreak.
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Affiliation(s)
- Young Kyung Yoon
- Division of Infectious Diseases, Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea
| | - Hee Sun Sim
- Institute of Emerging Infectious Diseases, Korea University College of Medicine, Seoul, Korea
| | - Jeong Yeon Kim
- Division of Infectious Diseases, Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea
- Institute of Emerging Infectious Diseases, Korea University College of Medicine, Seoul, Korea
| | - Dae Won Park
- Division of Infectious Diseases, Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea
- Institute of Emerging Infectious Diseases, Korea University College of Medicine, Seoul, Korea
| | - Jang Wook Sohn
- Division of Infectious Diseases, Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea
- Institute of Emerging Infectious Diseases, Korea University College of Medicine, Seoul, Korea
| | - Kyung Ho Roh
- Department of Laboratory Medicine, Korea University College of Medicine, Seoul, Korea
| | - Seung Eun Lee
- Infection Control Unit, Korea University College of Medicine, Seoul, Korea
| | - Min Ja Kim
- Division of Infectious Diseases, Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea
- Institute of Emerging Infectious Diseases, Korea University College of Medicine, Seoul, Korea
- Infection Control Unit, Korea University College of Medicine, Seoul, Korea
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Billström H, Sullivan A, Lund B. Cross-transmission of clinical Enterococcus faecium in relation to esp and antibiotic resistance. J Appl Microbiol 2009; 105:2115-22. [PMID: 19120657 DOI: 10.1111/j.1365-2672.2008.03983.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS To investigate clonality among clinical Enterococcus faecium isolates and normal intestinal microflora isolates as well as cross-transmission between patients in relation to the presence of the esp gene and antibiotic resistance. METHODS AND RESULTS Blood-culture isolates (n = 101) deriving from tertiary, secondary and primary hospitals were analysed. Antibiotic susceptibility was investigated. Polymerase chain reaction and pulsed-field gel electrophoresis were used for detection of esp and genotyping, respectively. Nearly half (43%) of the patients included were involved in a cross-transmission event with Ent. faecium. These strains disseminated both within and between all hospitals. The antibiotic resistance and presence of esp were highest in isolates from the tertiary hospital. Isolates harbouring esp showed less genetic diversity compared with esp negative ones. CONCLUSIONS Cross-transmission with Ent. faecium between patients was readily detected, indicating that hospital-adapted clones circulate within and between hospitals. Acquired characteristics, such as antibiotic resistance and esp, seem to accumulate in the isolates disseminating in the tertiary hospital. SIGNIFICANCE AND IMPACT OF THE STUDY It is important to characterize Ent. faecium isolates causing infections and to determine the extent of dissemination in order to prevent further spread of these pathogens.
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Affiliation(s)
- H Billström
- Division of Clinical Microbiology, Karolinska Institutet, Karolinska University Hospital, Huddinge, Stockholm, Sweden
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Diversity of Tn1546 and its role in the dissemination of vancomycin-resistant enterococci in Portugal. Antimicrob Agents Chemother 2008; 52:1001-8. [PMID: 18180362 DOI: 10.1128/aac.00999-07] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
We characterized the molecular diversity of vanA vancomycin-resistant enterococci (VRE; 176 isolates/87 pulsed-field gel electrophoresis types) from different sources and cities in Portugal (1996 to 2004): (i) food animals (FA; n = 38 isolates out of 31 samples), hospitalized humans (HH; n = 101/101), healthy human volunteers (HV; n = 7/4), and environmental sources (n = 30/10). Some strains were isolated from different hosts and persistently recovered for years. Twenty-four Tn1546 variants were identified, all located on plasmids (30 to 250 kb). Some Tn1546 variants were associated with specific sources such as FA (3 types), HH (11 types), or HV (1 type), while others were recovered from isolates of different origins (8 types). Polymorphisms in the central vanRSHA region of Tn1546 were scarcely detected, while alterations upstream of vanR and downstream of vanA were frequently identified involving mutations (vanS and vanX), deletions (vanY), insertions (IS1216V, ISEf1, and IS19; sequences with or without homology with others available in GenBank databases), and different genetic rearrangements. Most Tn1546 variants contained IS1216V (14 types) or ISEf1 (6 types). IS1216V was found alone or associated with an IS3-like element at different orientations and positions in Tn1546 from human, animal, and environmental samples. ISEf1 was located within vanX-vanY region at nucleotide 9044 of Tn1546 variants mostly associated with clinical isolates, suggesting a common genetic platform. IS19 was observed within the vanX-vanY region in one Tn1546 variant from poultry. Recent spread of VRE in Portugal reflects a complex epidemiology involving both clonal spread and plasmid dissemination containing a variety of Tn1546 types. Apparent Tn1546 heterogeneity among enterococci from human, animal, and environmental sources might reflect frequent genetic exchange events and evolution of particular widely disseminated genetic elements.
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Deshpande LM, Fritsche TR, Moet GJ, Biedenbach DJ, Jones RN. Antimicrobial resistance and molecular epidemiology of vancomycin-resistant enterococci from North America and Europe: a report from the SENTRY antimicrobial surveillance program. Diagn Microbiol Infect Dis 2007; 58:163-70. [PMID: 17368801 DOI: 10.1016/j.diagmicrobio.2006.12.022] [Citation(s) in RCA: 205] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2006] [Accepted: 12/11/2006] [Indexed: 10/23/2022]
Abstract
Increases in prevalence of vancomycin-resistant enterococci (VRE) have been documented globally since its emergence in the 1980s. A SENTRY Antimicrobial Surveillance Program (2003) objective monitored VRE isolates with respect to antimicrobial susceptibility trends, geographic resistance variability, and clonal dissemination. In 2003, VRE isolates from North America (United States and Canada, n = 839, 26 sites) and Europe (n = 56, 10 sites) were susceptibility tested using Clinical and Laboratory Standards Institute (CLSI) reference methodologies. Based on resistance profiles, 155 isolates displayed similar multidrug-resistant (MDR) profiles and were temporally related; these were subsequently submitted for typing by pulsed-field gel electrophoresis (PFGE). Most of the submitted isolates were Enterococcus faecium (91.0%) and Enterococcus faecalis (7.8%). Among VRE, the VanA phenotype was more prevalent in North America (76%) than Europe (40%), and all isolates had elevated resistance rates to other antimicrobial classes including the following: 1) chloramphenicol resistance among E. faecalis being greater in North America than in Europe (28.6% versus 7.1%, respectively) but reversed among E. faecium (0.5% and 15.0%, the latter due to clonal occurrences); 2) ciprofloxacin resistance in North America >99% for both species and in Europe varying from 85.7% to 87.5%; 3) rare occurrences of linezolid resistance in North America (0.8% to 1.8%) due to G2576U ribosomal mutation; 4) higher quinupristin/dalfopristin resistance observed among European E. faecium strains (10.0% versus 0.6%); and 5) higher rifampin resistance rates among European E. faecalis (21.4% versus 5.4%). Thirty-five MDR epidemic clusters were identified by PFGE in 21 North American and 2 European medical centers including the following: 1) VanA (20 sites, 27 clonal occurrences) and VanB (1 site, 2 clonal occurrences); 2) elevated quinupristin/dalfopristin MIC results (not vatD/E, 3 sites); and 3) chloramphenicol resistance (chloramphenicol acetyltransferase-positive strains, 3 sites). The esp gene, part of the putative E. faecium pathogenicity island and a marker for the clonal complex-17 lineage, was detected in 76% of vancomycin-resistant E. faecium. Clonal spread appears to be a dominant factor of MDR VRE dissemination on both continents, and further monitoring is critical to assist in the control of these resistant pathogens.
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Corso AC, Gagetti PS, Rodríguez MM, Melano RG, Ceriana PG, Faccone DF, Galas MF. Molecular epidemiology of vancomycin-resistant Enterococcus faecium in Argentina. Int J Infect Dis 2007; 11:69-75. [PMID: 16793306 DOI: 10.1016/j.ijid.2006.02.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2005] [Revised: 01/30/2006] [Accepted: 02/01/2006] [Indexed: 10/24/2022] Open
Abstract
OBJECTIVE To characterize the mechanism of glycopeptide resistance and to determine the genetic relatedness among strains by pulsed-field gel electrophoresis (PFGE) in vancomycin-resistant Enterococcus faecium from Argentina. MATERIALS AND METHODS A total of 189 vancomycin-resistant single-patient isolates of Enterococcus faecium recovered between January 1997 and December 2000 from 30 hospitals in Argentina were studied. Minimum inhibitory concentrations were determined by the agar dilution method and van genes were detected by PCR. PFGE was used for molecular typing. RESULTS All isolates except three (vanB) were of genotype vanA. For 189 vancomycin-resistant Enterococcus faecium, SmaI-PFGE indicated 35 clonal types. Most of the isolates (56%) belonged to the same clonal type 1, which was present in 19 hospitals and dominant in 17. CONCLUSIONS The emergence of vancomycin-resistant Enterococcus faecium in Argentina seems to be related to the intra- and inter-hospital dissemination of an epidemic clone carrying the vanA element.
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Affiliation(s)
- Alejandra C Corso
- Servicio Antimicrobianos, Instituto Nacional de Enfermedades Infecciosas - ANLIS Dr. Carlos G. Malbrán, Av. Velez Sarsfield 563 (1281), Buenos Aires, Argentina.
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Lund B, Billström H, Edlund C. Increased conjugation frequencies in clinical Enterococcus faecium strains harbouring the enterococcal surface protein gene esp. Clin Microbiol Infect 2006; 12:588-91. [PMID: 16700712 DOI: 10.1111/j.1469-0691.2006.01436.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This study compared the in-vitro ability of Enterococcus faecium isolates of different origin to acquire vanA by conjugation in relation to the occurrence of the esp gene. In total, 29 clinical isolates (15/29 esp+), 30 normal intestinal microflora isolates (2/30 esp+) and one probiotic strain (esp-) were studied with a filter-mating assay. Conjugation events were confirmed by PCR and pulsed-field gel electrophoresis. Among the infection-derived isolates, the esp+ isolates had higher conjugation frequencies compared with esp- isolates (p < 0.001), with a median value of 6.4 x 10(-6) transconjugants/donor. The probiotic strain was shown to acquire vanA vancomycin resistance in in-vitro filter mating experiments.
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Affiliation(s)
- B Lund
- Division of Clinical Bacteriology, Department of Laboratory Medicine, Huddinge University Hospital, Karolinska Institutet, Stockholm, Sweden
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Novais C, Sousa JC, Coque TM, Peixe LV. Molecular characterization of glycopeptide-resistant Enterococcus faecium isolates from Portuguese hospitals. Antimicrob Agents Chemother 2005; 49:3073-9. [PMID: 15980404 PMCID: PMC1168715 DOI: 10.1128/aac.49.7.3073-3079.2005] [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: 01/14/2023] Open
Abstract
Fifty-one pulsed-field gel electrophoresis types and 17 Tn1546 variants were identified among 101 Enterococcus faecium isolates recovered in three distant Portuguese hospitals. Intra- and interhospital dissemination of specific strains and Tn1546 types was detected, which might largely contribute to the endemicity of vancomycin-resistant E. faecium in Portuguese hospitals, as happened previously in other geographical locations.
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Affiliation(s)
- Carla Novais
- REQUIMTE, Laboratório de Microbiologia, Faculdade de Farmácia, Universidade do Porto, Rua Aníbal Cunha, 164, 4050-030 Porto, Portugal
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Coque TM, Willems RJL, Fortún J, Top J, Diz S, Loza E, Cantón R, Baquero F. Population structure of Enterococcus faecium causing bacteremia in a Spanish university hospital: setting the scene for a future increase in vancomycin resistance? Antimicrob Agents Chemother 2005; 49:2693-700. [PMID: 15980338 PMCID: PMC1168696 DOI: 10.1128/aac.49.7.2693-2700.2005] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Over an 8-year period (1995 to 2002), 86 Enterococcus faecium blood isolates from 84 patients, of which 54 were ampicillin resistant (AREF) and 32 were ampicillin susceptible (ASEF), were studied in a university hospital (1,200 beds; serving a population of 600,000) in Spain, a country characterized by a near-absence of resistance to vancomycin and very high rates of ampicillin resistance among enterococci. Clonal relatedness by pulsed-field gel electrophoresis (PFGE), antibiotic susceptibility, presence of the virulence/epidemicity genes esp(Efm) and hyl(Efm), and identification of purK alleles were studied. A group of isolates was also analyzed by amplified fragment length polymorphism (AFLP) and multilocus sequence typing. Medical charts (30 variables collected) were reviewed for 60/84 patients. ASEF showed high clonal diversity (32 PFGE types, 11 purK alleles, 4 AFLP genogroups), did not harbor putative virulence genes, and had no specific association with hospital acquisition. AREF isolates belonged to a clonal complex (CC) of genetically related strains (purK-1, AFLP genogroup C), occasionally harboring putative virulence traits, and were from patients with particular risk factors. Within this CC, previously associated with vancomycin-resistant E. faecium isolates causing outbreaks worldwide (W. L. Homan et al., J. Clin. Microbiol. 40:1963-1971, 2002), a great genetic diversity of antibiotic resistance and virulence/epidemicity profiles was found. Associations between esp and a >7-day hospital stay and between purK-1, hospital location, and nosocomial acquisition were noted (P < 0.001). These findings reflect the importance of local environmental differences in the evolution of this CC, suggesting that the emergence of vancomycin resistance among AREF strains in Spain may be a question of time.
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Affiliation(s)
- Teresa M Coque
- Departamento de Microbiologíca, Servicio de Microbiología, Hospital Universitario Ramón y Cajal, Carretera de Colmenar, km. 9.1, Madrid 28034, Spain.
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Corso A, Faccone D, Gagetti P, Togneri A, Lopardo H, Melano R, Rodríguez V, Rodriguez M, Galas M. First report of VanA Enterococcus gallinarum dissemination within an intensive care unit in Argentina. Int J Antimicrob Agents 2005; 25:51-6. [PMID: 15620826 DOI: 10.1016/j.ijantimicag.2004.07.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2004] [Accepted: 07/06/2004] [Indexed: 11/24/2022]
Abstract
Enterococcusgallinarum is intrinsically resistant to low levels of vancomycin and has been described as a colonizing microorganism causing bacteraemia and infection among immunosupresed patients. Between August 2000 and February 2001, 15 highly glycopeptide-resistant E. gallinarum isolates, one from blood and the remaining from rectal swabs, were recovered in a general hospital of Buenos Aires Province, Argentina. All isolates were characterized by biochemical assays, and displayed MICs of vancomycin in the range 16-128 mg/l and MICs of teicoplanin in the range 16-32 mg/l. In all cases, PCR analysis yield positive results for both vanC1 and vanA genes. E. gallinarum isolates were classified as two clonal types by SmaI-PFGE: clone A (n = 8) and clone B (n = 7) and both harboured a transferable vanA element.
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Affiliation(s)
- A Corso
- Servicio Antimicrobianos, Dpto. Bacteriología, Instituto Nacional de Enfermedades Infecciosas - ANLIS Dr. Carlos G. Malbrán, Av. Velez Sarsfield 563 (1281), Buenos Aires, Argentina.
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Novais C, Coque TM, Sousa JC, Baquero F, Peixe L. Local genetic patterns within a vancomycin-resistant Enterococcus faecalis clone isolated in three hospitals in Portugal. Antimicrob Agents Chemother 2004; 48:3613-7. [PMID: 15328141 PMCID: PMC514734 DOI: 10.1128/aac.48.9.3613-3617.2004] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Eight pulsed-field gel electrophoresis subtypes and six Tn1546 variants were identified among Enterococcus faecalis isolates of a single clone recovered in three geographically separate Portuguese hospitals. Some clonal subtypes were found in particular hospitals, and Tn1546 variants were either widespread or confined to some of them. We also report on the first Tn1546 transposon containing an ISEf1 insertion.
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Affiliation(s)
- Carla Novais
- Laboratório de Microbiologia, Faculdade de Farmácia, Universidade do Porto, Rua Aníbal Cunha, 4050 Porto, Portugal
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Lund B, Edlund C. Bloodstream isolates of Enterococcus faecium enriched with the enterococcal surface protein gene, esp, show increased adhesion to eukaryotic cells. J Clin Microbiol 2004; 41:5183-5. [PMID: 14605157 PMCID: PMC262495 DOI: 10.1128/jcm.41.11.5183-5185.2003] [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: 12/22/2022] Open
Abstract
Infection-derived Enterococcus faecium strains enriched with esp had increased ability to adhere to Caco-2 cells (P < 0.05) and were less genetically diverse than esp-negative isolates. esp-negative E. faecium fecal isolates from healthy individuals adhered significantly better than esp-negative infection isolates (P < 0.05), indicating additional factors of importance to adhesion.
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Affiliation(s)
- Bodil Lund
- Division of Clinical Bacteriology, Huddinge University Hospital, Karolinska Institutet, Stockholm, Sweden
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Papp L, McNeeley DF, Projan SJ, Bradford PA, Frost A, Nesin M. Recurrent episodes of shock-like syndrome caused by the same strain of vancomycin-resistant Enterococcus faecium in a pediatric patient. Microb Drug Resist 2003; 9:307-12. [PMID: 12959410 DOI: 10.1089/107662903322286526] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We present the case of a hospitalized pediatric patient with short bowel syndrome who was dependent upon total parenteral nutrition for 17 months. Shortly after admission she became colonized with vancomycin-resistant Enterococcus faecium (VRE) and developed 12 distinct episodes of serious infection associated with it. The course of VRE colonization and infections in this patient was studied through analysis of 40 representative isolates obtained from different sites during distinct episodes of infection. Standard microbiological techniques, automated ribosomal DNA typing, polymerase chain reaction, and pulsed-field gel electrophoresis (PFGE) were used. All isolates except for the one associated with the initial episode of bacteremia were VRE, and were multidrug resistant. The last four episodes of infection were caused by isolates resistant to all tested antibiotics except for intermediate susceptibility to chloramphenicol. The vanA genotype was a source of vancomycin resistance in all VRE isolates. Both ribotyping and PFGE showed two distinct clones of VRE in clinical and stool surveillance isolates: one was associated with clinical illness and the other was not associated with infection. Recurrent VRE infections occur as a consequence of prolonged gastrointestinal colonization. Morbidity is associated with host factors, the presence of co-pathogens, and possibly intrinsically more virulent VRE strain.
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Affiliation(s)
- Laszlo Papp
- Department of Pediatrics, Weill Medical College of Cornell University, New York, NY 10021, USA
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17
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Zanella RC, Brandileone MCC, Bokermann S, Almeida SCG, Valdetaro F, Vitório F, Moreira MDFA, Villins M, Salomão R, Pignatari ACC. Phenotypic and genotypic characterization of VanA Enterococcus isolated during the first nosocomial outbreak in Brazil. Microb Drug Resist 2003; 9:283-91. [PMID: 12959407 DOI: 10.1089/107662903322286490] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We report the phenotypic and genotypic characterization of 50 VanA Enterococcus clinical isolates from infected patients and 97 isolates from colonized patients obtained during a nosocomial outbreak in a single hospital in São Paulo, Brazil during 1998. The identification of strains to the species level by conventional biochemical and phenotypic tests and by multiplex PCR assay had 100% agreement. Both E. faecalis and E. faecium were isolated from patients during this outbreak. The vanA genotype was confirmed by PCR. Antibiotic susceptibility testing showed that E. faecium isolates are generally less susceptible to antibiotics than E. faecalis. By PCR, 24 of 26 VRE strains tested carried the Tn1546 element. Pulsed-field gel electrophoresis identified five distinct patterns for E. faecalis (A, B, C, D, E) and three for E. faecium (M, N, and O). A single PFGE pattern was identified in the majority of strains of each species and does not discriminate between case and carrier isolates.
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Calfee DP, Giannetta ET, Durbin LJ, Germanson TP, Farr BM. Control of endemic vancomycin-resistant Enterococcus among inpatients at a university hospital. Clin Infect Dis 2003; 37:326-32. [PMID: 12884155 DOI: 10.1086/376624] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2002] [Accepted: 03/20/2003] [Indexed: 11/03/2022] Open
Abstract
We sought to determine the ability of surveillance cultures and isolation of vancomycin-resistant Enterococcus (VRE)-colonized patients to control nosocomial VRE infection and colonization during a 5-year period (November 1994 through October 1999). During this period, VRE colonization was limited to 0.82% of admissions. The incidence of VRE infection was 0.12 cases per 1000 patient-days (attack rate, 0.07%). Colonized patients were first identified by surveillance (95%) or routine clinical cultures (5%); 14% of colonized patients had a positive clinical culture a median of 15 days after a positive surveillance culture. Ten percent of colonized patients were identified by surveillance at the time of transfer from another health care facility. Identification of these colonized patients was associated with reduction from a peak incidence rate of 2.07% to a rate of 1.25% and stabilization at this lower level. The use of surveillance cultures to identify and isolate patients with asymptomatic colonization can provide sustained control of the spread of VRE within a health care facility.
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Affiliation(s)
- David P Calfee
- Department of Internal Medicine, University of Virginia School of Medicine, Charlottesville, VA, USA.
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19
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Muto CA, Jernigan JA, Ostrowsky BE, Richet HM, Jarvis WR, Boyce JM, Farr BM. SHEA guideline for preventing nosocomial transmission of multidrug-resistant strains of Staphylococcus aureus and enterococcus. Infect Control Hosp Epidemiol 2003; 24:362-86. [PMID: 12785411 DOI: 10.1086/502213] [Citation(s) in RCA: 988] [Impact Index Per Article: 47.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND Infection control programs were created three decades ago to control antibiotic-resistant healthcare-associated infections, but there has been little evidence of control in most facilities. After long, steady increases of MRSA and VRE infections in NNIS System hospitals, the Society for Healthcare Epidemiology of America (SHEA) Board of Directors made reducing antibiotic-resistant infections a strategic SHEA goal in January 2000. After 2 more years without improvement, a SHEA task force was appointed to draft this evidence-based guideline on preventing nosocomial transmission of such pathogens, focusing on the two considered most out of control: MRSA and VRE. METHODS Medline searches were conducted spanning 1966 to 2002. Pertinent abstracts of unpublished studies providing sufficient data were included. RESULTS Frequent antibiotic therapy in healthcare settings provides a selective advantage for resistant flora, but patients with MRSA or VRE usually acquire it via spread. The CDC has long-recommended contact precautions for patients colonized or infected with such pathogens. Most facilities have required this as policy, but have not actively identified colonized patients with surveillance cultures, leaving most colonized patients undetected and unisolated. Many studies have shown control of endemic and/or epidemic MRSA and VRE infections using surveillance cultures and contact precautions, demonstrating consistency of evidence, high strength of association, reversibility, a dose gradient, and specificity for control with this approach. Adjunctive control measures are also discussed. CONCLUSION Active surveillance cultures are essential to identify the reservoir for spread of MRSA and VRE infections and make control possible using the CDC's long-recommended contact precautions.
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Affiliation(s)
- Carlene A Muto
- Division of Hospital Epidemiology and Infection Control, UPMC-P, Pittsburgh, Pennsylvania 15213, USA
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20
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Srinivasan A, Song X, Ross T, Merz W, Brower R, Perl TM. A prospective study to determine whether cover gowns in addition to gloves decrease nosocomial transmission of vancomycin-resistant enterococci in an intensive care unit. Infect Control Hosp Epidemiol 2002; 23:424-8. [PMID: 12186206 DOI: 10.1086/502079] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND Vancomycin-resistant enterococci (VRE) remain a significant nosocomial pathogen. Current guidelines of the Hospital Infection Control Practices Advisory Committee (HICPAC) of the Centers for Disease Control and Prevention (CDC) recommend the use of gowns and gloves for some interactions with VRE-infected or -colonized patients to prevent nosocomial transmission of VRE. OBJECTIVE To assess the effect of disposable cover gowns on preventing nosocomial transmission of VRE. DESIGN AND SETTING Prospective study in a 16-bed medical intensive care unit of a university teaching hospital. PATIENTS All patients who were at risk to acquire VRE, were admitted to the intensive care unit from August 1998 to January 1999, and had at least two perirectal cultures were included in the analysis of VRE acquisition. INTERVENTION VRE isolation precautions were changed from gowns and gloves to gloves alone. MAIN OUTCOME risk factors for VRE acquisition. RESULTS The VRE acquisition rate was 1.80 cases per 100 days at risk in the gown and gloves period compared with 3.78 in the gloves only period (P = .04). In a proportional hazards model adjusted for length of stay, gloves only precautions with a hazard ratio of 2.5 (P = .02; 95% confidence interval, 1.2 to 5.3) were the only independent risk factor for VRE acquisition. CONCLUSION Our data lend support to current HICPAC recommendations for the use of cover gowns to decrease nosocomial transmission of VRE.
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Affiliation(s)
- Arjun Srinivasan
- Division of Infectious Diseases, Johns Hopkins Medical Institutions, Baltimore, Maryland 21287-5425, USA
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21
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Lund B, Adamsson I, Edlund C. Gastrointestinal transit survival of an Enterococcus faecium probiotic strain administered with or without vancomycin. Int J Food Microbiol 2002; 77:109-15. [PMID: 12076027 DOI: 10.1016/s0168-1605(02)00047-8] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The primary aim of this study was to evaluate if an ingested probiotic, containing viable Enterococcus faecium could survive gastrointestinal transit and if so, correlate the amount of the recovered probiotic strain with the host's own enterococci. The second aim was to investigate if simultaneous vancomycin intake influenced the survival and persistence of the probiotic strain and the stability of endogenous enterococci strains. Twenty healthy volunteers were given the probiotic product once daily for 10 days. Half of the subjects were simultaneously given vancomycin. Isolates of E. faecium strains were genotypically or phenotypically analysed with pulsed-field gel electrophoresis (PFGE) and the PhenePlate system, respectively. In eight of the ten volunteers given only the probiotic, the ingested E. faecium could be detected on day 10, while in none on day 31. From subjects given both probiotic and vancomycin no ingested E. faecium could be detected on day 10 or day 31. The estimated amount of ingested E. faecium recovered from faeces on day 10 ranged from 1.2 x 10(3) to 4.2 x 10(6) colony forming units per gram faeces, which in several cases were a substantial part of the total amount of E. faecium. The E. faecium isolated before probiotic plus vancomycin administration showed no close relationship to the ones isolated 3 weeks after ceased intake in any subjects. In conclusion, the ingested E. faecium strain can survive gastrointestinal transit. After intake, the E. faecium probiotic strain might become a large part of the total E. faecium population. The occurrence of the probiotic strain in the human gut seems to be transient after intake stop. Re-colonization of E. faecium after simultaneous probiotic plus vancomycin intake occurs mainly with strains without close genetic relationship to the strains harboured before treatment or to the ingested E. faecium strain.
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Affiliation(s)
- Bodil Lund
- Division of Clinical Bacteriology, Huddinge University Hospital, Karolinska Institutet, Stockholm, Sweden
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22
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Lund B, Agvald-Ohman C, Hultberg A, Edlund C. Frequent transmission of enterococcal strains between mechanically ventilated patients treated at an intensive care unit. J Clin Microbiol 2002; 40:2084-8. [PMID: 12037069 PMCID: PMC130827 DOI: 10.1128/jcm.40.6.2084-2088.2002] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The objectives of this investigation were to study the respiratory tract colonization and transmission of enterococci between 20 patients treated with mechanical ventilation at an intensive care unit (ICU), to compare genotyping with phenotyping, and to determine the antibiotic susceptibilities of the isolated enterococci. Samples were collected from the oropharynx, stomach, subglottic space, and trachea within 24 h of intubation, every third day until day 18, and thereafter every fifth day until day 33. Enterococcal isolates (n = 170) were analyzed by pulsed-field gel electrophoresis and with the PhenePlate (PhP) system. The antimicrobial susceptibilities to five agents were determined. Seventeen of the 20 subjects were colonized with enterococci in the respiratory tract; 12 were colonized in the lower respiratory tract. Genotype analyses suggested that 13 patients were involved in a transmission event, including all patients intubated more than 12 days. In conclusion, colonization of resistant enterococci in the respiratory tract of intubated patients treated at an ICU was common. Transmission of enterococci between patients occurred frequently. Prolonged intubation period seems to be a risk factor for enterococcal cross-transmission.
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Affiliation(s)
- Bodil Lund
- Division of Clinical Bacteriology, Huddinge University Hospital, Karolinska Institutet, Stockholm, Sweden
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23
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Woodford N. Epidemiology of the genetic elements responsible for acquired glycopeptide resistance in enterococci. Microb Drug Resist 2002; 7:229-36. [PMID: 11759084 DOI: 10.1089/10766290152652774] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Five genotypes of acquired glycopeptide resistance have been documented in enterococci, with vanA and vanB being the most globally widespread and prevalent. Resistance results from the production of peptidoglycan precursors with reduced binding affinity for glycopeptides and is encoded by complex clusters of van genes. The prototype VanA element is Tn1546, a 10.8-kb transposon that carries the vanRSHAXYZ genes. Diverse VanA elements exist, but all share the vanRSHAX cluster and are believed to be derived from a Tn1546 progenitor. The sequences of these genes are remarkably conserved, with only a few point mutations identified. VanA elements do however vary by the presence of deletions and insertion sequences (IS) in nonessential genes (orf1, orf2, vanY, and vanZ) and intergenic regions. IS transposition probably plays a key role in VanA element evolution. By contrast, vanB gene clusters show greater sequence divergence. Three vanB alleles have been reported, of which vanB2 appears to be the most widespread, generally as part of Tn5382 and related elements. To date, only four Enterococcus faecium strains with VanD resistance have been reported, and each contained a distinct vanD allele. The VanE and VanG types have each been identified in single strains of Enterococcus faecalis. The existence of distinct genotypes, together with the allelic nature of vanB and vanD, suggests that van clusters have transferred to enterococci on multiple occasions from undefined donor species, with subsequent horizontal dissemination, particularly of VanA and VanB elements, among enterococci. Characterization of glycopeptide resistance elements yields information on their evolution and broadens our insights into the epidemiology of resistant enterococci.
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Affiliation(s)
- N Woodford
- Antibiotic Resistance Monitoring and Reference Laboratory, Central Public Health Laboratory, London, United Kingdom.
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24
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Sundsfjord A, Simonsen GS, Courvalin P. Human infections caused by glycopeptide-resistant Enterococcus spp: are they a zoonosis? Clin Microbiol Infect 2002; 7 Suppl 4:16-33. [PMID: 11688531 DOI: 10.1046/j.1469-0691.2001.00055.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Following the detection of glycopeptide-resistant enterococci (GRE) in 1986 and their subsequent global dissemination during the 1990s, many studies have attempted to identify the reservoirs and lines of resistance transmission as a basis for intervention. The eradication of reservoirs and the prevention of GRE spread is of major importance for two reasons: (i) the emergence of high-level glycopeptide resistance in invasive enterococcal clinical isolates that are already multiresistant, has left clinicians with therapeutic options that are only at the experimental stage; and (ii) the resistance genes may spread to more virulent bacterial species such as Staphylococcus aureus, Streptococcus pneumoniae and Clostridium difficile. VanA-type strains, resistant to high levels of both vancomycin and teicoplanin, are the most commonly encountered enterococci with acquired glycopeptide resistance in humans. A widespread VanA-type GRE reservoir was detected early in farm animals that were exposed to the glycopeptide growth-promoter avoparcin. Numerous studies have provided indirect evidence for the transfer of VanA-type GRE and their resistance determinants from animal reservoirs to humans. The data collected have expanded our understanding of the promiscuous nature of antibiotic resistance, and have provided the groundwork for logical decision-making with the objective of deterring the dissemination of resistant bacteria and of their resistance genes.
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Affiliation(s)
- A Sundsfjord
- Unité des Agents Antibactériens, Institut Pasteur, Paris, France.
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25
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Baran J, Paruchuri R, Ramanathan J, Riederer KM, Khatib R. Unrecognized cross-infection with vancomycin-resistant Enterococcus faccium and faecalis detected by molecular typing of blood isolates. Infect Control Hosp Epidemiol 2002; 23:172-3. [PMID: 12002229 DOI: 10.1086/503458] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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26
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Bonten MJ, Willems R, Weinstein RA. Vancomycin-resistant enterococci: why are they here, and where do they come from? THE LANCET. INFECTIOUS DISEASES 2001; 1:314-25. [PMID: 11871804 DOI: 10.1016/s1473-3099(01)00145-1] [Citation(s) in RCA: 281] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Vancomcyin-resistant enterococci (VRE) have emerged as nosocomial pathogens in the past 10 years, causing epidemiological controversy. In the USA, colonisation with VRE is endemic in many hospitals and increasingly causes infection, but colonisation is absent in healthy people. In Europe, outbreaks still happen sporadically, usually with few serious infections, but colonisation seems to be endemic in healthy people and farm animals. Vancomycin use has been much higher in the USA, where emergence of ampicillin-resistant enterococci preceded emergence of VRE, making them very susceptible to the selective effects of antibiotics. In Europe, avoparcin, a vancomycin-like glycopeptide, has been widely used in the agricultural industry, explaining the community reservoir in European animals. Avoparcin has not been used in the USA, which is consistent with the absence of colonisation in healthy people. From the European animal reservoir, VRE and resistance genes have spread to healthy human beings and hospitalised patients. However, certain genogroups of enterococci in both continents seem to be more capable of causing hospital outbreaks, perhaps because of the presence of a specific virulence factor, the variant esp gene. By contrast with the evidence of a direct link between European animal and human reservoirs, the origin of American resistance genes remains to be established. Considering the spread of antibiotic-resistant bacteria and resistance genes, the emergence of VRE has emphasised the non-existence of boundaries between hospitals, between people and animals, between countries, and probably between continents.
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Affiliation(s)
- M J Bonten
- Department of Internal Medicine and the Eijkman-Winkler Institute for Microbiology, Infectious Diseases, and Inflammation, University Medical Center Utrecht, The Netherlands.
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27
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Zachary KC, Bayne PS, Morrison VJ, Ford DS, Silver LC, Hooper DC. Contamination of gowns, gloves, and stethoscopes with vancomycin-resistant enterococci. Infect Control Hosp Epidemiol 2001; 22:560-4. [PMID: 11732785 DOI: 10.1086/501952] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE [corrected] To measure directly the rate of contamination, during routine patient examination, of gowns, gloves, and stethoscopes with vancomycin-resistant enterococci (VRE). SETTING A large, academic, tertiary-care hospital. PATIENTS Between January 1997 and December 1998, 49 patients colonized or infected with VRE were entered in the study. DESIGN After routine examination, the examiner's glove fingertips, gown (the umbilical region and the cuffs), and stethoscope diaphragm were pressed onto Columbia colistin-nalidixic acid (CNA) agar plates with 5% sheep blood plus vancomycin 6 pg/mL. The stethoscope diaphragm was sampled again after cleaning with a 70% isopropanol wipe. RESULTS VRE were isolated from at least 1 examiner site (gloves, gowns, or stethoscope) in 33 (67%) of 49 cases. Gloves were contaminated in 63%, gowns in 37%, and stethoscopes in 31%. All three items were positive for VRE in 24%. One case each had stethoscope and gown contamination without glove contamination. Only 1 (2%) of 49 stethoscopes was positive after wiping with an alcohol swab. Contamination at any site was more likely when the patient had a colostomy or ileostomy. Patients identified by rectal-swab culture alone were as likely to contaminate their examiners as were those identified by clinical specimens. CONCLUSIONS Our study revealed a high rate of examiner contamination with VRE. The similar risk of contamination identified by surveillance and clinical cases reinforces concerns that patients not known to be colonized with VRE could serve as sources for dissemination. Wiping with alcohol is effective in decontaminating stethoscopes.
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Affiliation(s)
- K C Zachary
- Infectious Disease Division Massachusetts General Hospital, Boston 02114-2696, USA
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28
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Farr BM, Salgado CD, Karchmer TB, Sherertz RJ. Can antibiotic-resistant nosocomial infections be controlled? THE LANCET. INFECTIOUS DISEASES 2001; 1:38-45. [PMID: 11871409 DOI: 10.1016/s1473-3099(01)00020-2] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Three decades ago infection-control programmes were created to control antibiotic-resistant nosocomial infections, but numbers of these infections have continued to increase, leading many to question whether control is feasible. Meticillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci were major problems during the 1990s. Many hospitals have tried antibiotic control but with limited efficacy against these pathogens. Studies of antibiotic restriction, substitution, and cycling have been promising, but more definitive data are needed. Increased compliance with hand hygiene would help but is unlikely to control this problem alone as a result of frequent contamination of other surfaces even when hands are cleansed and high transmission rates when hand hygiene is neglected. For 17 years, the Centers for Disease Control and Prevention have recommended contact precautions for preventing nosocomial spread of important antibiotic-resistant pathogens. Many studies confirm that this approach works when sufficient active-surveillance cultures are undertaken to detect the reservoir for spread. However, most healthcare facilities have not yet tried this approach.
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Affiliation(s)
- B M Farr
- University of Virginia Health System, Charlottesville 22908, USA.
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29
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Ostrowsky B, Steinberg JT, Farr B, Sohn AH, Sinkowitz-Cochran RL, Jarvis WR. Reality check: should we try to detect and isolate vancomycin-resistant enterococci patients? Infect Control Hosp Epidemiol 2001; 22:116-9. [PMID: 11232874 DOI: 10.1086/501874] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Antimicrobial resistance, including vancomycin resistance in enterococci (VRE), is a growing problem in healthcare facilities. This "Reality Check" session focused on the question of whether we should try to detect and isolate patients colonized or infected with VRE.
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Affiliation(s)
- B Ostrowsky
- Hospital Infections Program, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Public Health Service, United States Department of Health and Human Services, Atlanta, Georgia, USA
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30
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Simonsen GS, Myhre MR, Dahl KH, Olsvik O, Sundsfjord A. Typeability of Tn1546-like elements in vancomycin-resistant enterococci using long-range PCRs and specific analysis of polymorphic regions. Microb Drug Resist 2000; 6:49-57. [PMID: 10868807 DOI: 10.1089/mdr.2000.6.49] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Molecular subtyping of the VanA-type resistance element Tn1546 in an international collection of 81 genomically diverse vancomycin-resistant enterococci (VRE) from human, animal, and environmental reservoirs was evaluated by restriction analysis of long-range PCR amplicons (PCR-RFLP), single gene PCRs, Southern blot analysis of genomic digests, and partial DNA sequencing. A dominant Tn1546-RFLP in accordance with Enterococcus faecium BM4147 was detected in 43 of the 49 long-range PCR positive strains from ecologically diverse sources in several European countries and the US. Tn1546-like elements from the 32 (40%) long-range PCR negative strains were typed into 17 different groups by single-gene PCRs and Southern blot analysis of the ORF1, ORF2, vanS-vanH, vanX-vanY, and vanZ regions. All these isolates showed deletions in the ORF1 and/or vanZ primer binding regions explaining the failure of long-range PCR amplification. Enlarged vanS-vanH or vanX-vanY fragments were detected in 7 (22%) and 16 (50%) of the long-range PCR negative strains, respectively. The enlarged vanS-vanH regions of five clinical isolates from the US (n = 2), Ireland (n = 2), and Norway (n = 1) contained identical IS1251-like insertions indicating intercontinental spread of the vanA gene cluster. Intergenic vanS-vanH IS1251 insertions have so far not been reported in European studies. Structural rearrangements of Tn1546-like elements may represent single recombination events that can serve as fingerprints in the molecular examination of vanA gene cluster evolution and transmission. The optimal strategy for such analysis has yet to be determined. Two alternative long-range PCRs with subsequent RFLP analysis were successfully used to type the majority of vanA gene clusters in an ecologically and geographically heterogeneous VRE strain collection, but failed to detect and type a group of variant Tn1546-like elements truncated in the left-end ORF1/ORF2 region. Further subtyping of such variants should specifically target the polymorphic vanS-vanH and vanX-vanY regions.
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Affiliation(s)
- G S Simonsen
- Department of Medical Microbiology, University and University Hospital of Tromsø, Norway.
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31
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Farr BM. Protecting long-term care patients from antibiotic resistant infections: ethics, cost-effectiveness, and reimbursement issues. J Am Geriatr Soc 2000; 48:1340-2. [PMID: 11037026 DOI: 10.1111/j.1532-5415.2000.tb02612.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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32
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Kawalec M, Gniadkowski M, Hryniewicz W. Outbreak of vancomycin-resistant enterococci in a hospital in Gdask, Poland, due to horizontal transfer of different Tn1546-like transposon variants and clonal spread of several strains. J Clin Microbiol 2000; 38:3317-22. [PMID: 10970377 PMCID: PMC87380 DOI: 10.1128/jcm.38.9.3317-3322.2000] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Twenty-two vancomycin-resistant enterococcal (VRE) isolates of the VanA phenotype (21 Enterococcus faecium isolates and 1 E. faecalis isolate), representative of a large outbreak that occurred in a hospital in Gdańsk, Poland, were studied. All of the isolates demonstrated resistance to a wide variety of other antimicrobial agents in addition to glycopeptides. Several lines of evidence suggested that the outbreak most probably consisted of two epidemics that followed the independent introduction of VanA determinants into two separate hematological wards of the hospital. This hypothesis is supported by the fact that isolates recovered in these wards possessed two different polymorphs of the highly conserved DNA region encompassing the vanRSHAX genes and two distinct polymorph types of Tn1546-like transposons, which contain these genes. According to pulsed-field gel electrophoresis data, the outbreak in the adult hematology ward (HW) was highly polyclonal, which suggested a major role for the horizontal transmission of Tn1546-like elements among nonrelated strains of E. faecium and E. faecalis in this environment. On the other hand, the outbreak in the pediatric hematology ward (PHW) was most probably due to the clonal spread of two epidemic E. faecium strains, which had exchanged a plasmid carrying the Tn1546-like transposon. Restriction fragment length polymorphism studies of transposons and their insertion loci in plasmid DNA have suggested that numerous isolates from both HW and PHW contained two or more copies of Tn1546-like elements that underwent diversification due to various genetic modifications. The reported data demonstrated a very complex epidemiology of the first, and up to now the only, VanA VRE outbreak characterized in Poland.
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Affiliation(s)
- M Kawalec
- Sera and Vaccines Central Research Laboratory, 00-725 Warsaw, Poland
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