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Introduction- Enterococci are part of normal intestinal flora of humans and animals but have also emerged as important pathogens responsible for serious infections in hospital and community acquired infections.it is second most common cause of nosocomial infections in gastrointestinal tract, wound and genitourinary tract. To process all the clinicalAim- samples from various department in our hospital, for isolation of Enterococci spp. To speciate the isolates & to have resistance pattern of the isolates of vancomycin total 926 sample were collected from both outMaterial & Methods- patients and in patient in all clinical departments and transported to microbiology laboratory. specimens were processed by inoculating on to blood agar, MacConkey Agar, nutrient agar, potassium tellurite agar and incubated at 37°C for24-48 hr. Enterococci were identified by their typical arrangement in and salt tolerance test Gram stain, bile esculin test and biochemical tests. Antimicrobial susceptibility patterns were determined by performing Kirby-Bauer disc diffusion method and Minimum inhibitory concentration (MIC) values were identified by tube dilution methods. Result- a total of 926 sample, 645 (69.72%) were culture positive and 281 (30.28%) were culture negative. Among 645 culture positive cases, 81(12.55%) were Enterococcus faecalis. Antimicrobial susceptibility & MIC done as per standard protocols. The E. Faecalis showed 99% sensitive to Vancomycin. the resistance to vancomycin was 1% & further confirmed by MIC via tube dilution methods. In which MIC was ?32 ?g/ml in one isolate. About 8 of Enterococcal strains showed MIC of 0.0125?g/ml. species level identification of Enterococcus is important forConclusions- epidemiological study and also for analysis of drug resistant pattern. Effective detection of vancomycin resistance helps in reducing the morbidity and mortality of VRE in hospitalized patients
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BACKGROUND: The transition from manual processing of patient samples to automated workflows in medical microbiology is challenging. Although automation enables microbiologists to evaluate all samples following the same incubation period, the essential incubation times have yet to be determined. We defined essential incubation times for detecting methicillin-resistant Staphylococcus aureus (MRSA), multi-drug resistant gram-negative bacteria (MDRGN), and vancomycin-resistant enterococci (VRE). METHODS: We monitored the growth kinetics of MRSA, MDRGN, and VRE between two and 48 hours on chromogenic media to establish the time points of first growth, single colony appearance, and typical morphology for 102, 104, 106, and 108 colony forming units/mL. Subsequently, we imaged plates inoculated with 778 patient samples after 20, 24, and 36 hours. RESULTS: The first growth, single colony appearance, and typical morphology time points were inoculum-dependent. First growth appeared after 6–18 hours, 4–18 hours, and 8–48 hours for MRSA, MDRGN, and VRE, respectively, and single colonies appeared at 12–18 hours, 6–20 hours, and 12–48 hours, respectively. Typical morphology was visible at 14–22 hours and 12–48 hours for MRSA and VRE, but was not determined for MDRGN. By examining patient samples, ≥98% of MRSA and MDRGN were visible 20 hours after the start of incubation. Following 24 hours of incubation, only 79.5% of VRE were clearly visible on the respective plates. CONCLUSIONS: An incubation time of 20 hours is sufficient for detecting MRSA and MDRGN. VRE growth is much slower and requires additional imaging after 36 hours.
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Humans , Automation , Automation, Laboratory , Bacteria , Gram-Negative Bacteria , Kinetics , Methicillin-Resistant Staphylococcus aureus , Vancomycin-Resistant EnterococciABSTRACT
The aim of this study is to determine the diversity of virulence genes carried by different vancomycin-resistant enterococci (VRE),which will provides a basis for studying pathogenic mechanism of VRE.Microdilution-based drug sensitivity test was applied to detect the vancomycin resistance of 490 Enterococcus faecium isolates and 862 Enterococcus faecalis isolates in Zhejiang area.The seven virulence genes (ace,asa1,cylA,efaA,esp,gelE and hyl) in the isolates of VRE were detected by PCR.According to the results of drug sensitivity test,10％ of the E.faecium isolates (49/490) and 0.8％ of the E.faecalis (7/862) were identified as VRE.In the vancomycin-resistant E.faecium isolates,five isolates were negative for any of the target genes and the other 44 isolates were positive for asa1,esp,gelE and hyl genes alone,in which the esp (73.5％,36/49) and hyl (53.1％,26/49) were the predominant genes and single or double virulence genes acted as the major carrying models.Except for the hyl gene,the vancomycin-resistant E.faecalis isolates were positive for the other six pathogenic genes,and the isolates could carry 3-6 pathogenic genes.All the data indicate that E.faeciurn is the major species of VRE in the local area,and the carrying rate,types and models of virulence genes in the vancomycin-resistant E.faecium and E.faecalis isolates are obviously different.
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The increasing reports of vancomycin‑resistant enterococci (VRE) as a cause of neonatal septicemia are of recent interest. However, in majority of the cases, the source of VRE could not be located. As a consequence, the real importance of VRE and its control measures is undermined. Herein, we report a case of neonatal septicemia due to VRE (Enterococcus faecalis) of vanA genotype with VRE carriage in stool of the neonates as a possible source of sepsis. The report put forwards some lacunae in the infection control practices that are presently followed in the country.
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Background: The aim of this study was to find out the clinical correlation between the presence of vancomycin‑resistant genes (van A and van B) and their expression as detected by phenotypic tests in colonized patients and in clinical isolates. Materials and Methods: Enterococci were isolated from various clinical samples and also from fecal specimens of colonized patients at the time of admission, after 48 h and after 5 days of admission. Identification to species level was done using standard methods. Vancomycin susceptibility in Enterococci was detected by disc diffusion test. Minimum inhibitory concentration was determined by agar dilution method. Multiplex polymerase chain reaction (PCR) was used to detect the presence of van genes. Results: Out of all the clinical and fecal samples processed, 12.0% isolates were either vancomycin resistant or vancomycin intermediate. Further, these isolates carried van A or van B genes as confirmed by PCR methods. Expression of van A gene was found to be more in Enterococcus faecalis (28.3%) as compared to Enterococcus faecium (25.0%) in both clinical and fecal isolates. 16.6% strains of E. faecium and 15.0% strains each of E. faecalis and Enterococcus gallinarum were found to carry van B genes. The overall prevalence of vancomycin resistant Enterococci (VRE) in colonized patients was about 9.6%. Prior administration of antibiotics had significant effect (P = 0.001) on VRE carriage. Urinary tract infection was the most common infection caused by vancomycin susceptible Enterococci (VSE), 105/214 (49.0%) and VRE, 13/36 (36.1%). There was no significant difference (P = 0.112) in the distribution of VRE and VSE in different infection types. Both clinical and fecal VRE showed maximum resistance to penicillin, ampicillin, and piperacillin. Resistance to linezolid was 2.8% in clinically isolated VRE. Conclusion: VRE in our study were found to be resistant to a number of commonly used antibiotics. The frequency of isolation of vancomycin resistant E. faecalis (VRE.fs), which is highly virulent, and the number of strains harboring van A gene in our hospital setup is high and needs to be addressed.
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Background & objectives: Vancomycin-resistant enterococci (VRE) have become one of the most challenging nosocomial pathogens with the rapid spread of the multi-drug resistant strain with limited therapeutic options. It is a matter of concern due to its ability to transfer vancomycin resistant gene to other organisms. The present study was undertaken to determine the emergence of vancomycin-resistant enterococci and the vanA gene among the isolates in a tertiary care hospital of North-East India. Methods: A total of 67 consecutive enterococcal isolates from different clinical samples were collected and identified by using the standard methods. Antibiogram was done by disk diffusion method and VRE was screened by the disk diffusion and vancomycin supplement agar dilution method. The minimum inhibitory concentration (MIC) value for vancomycin was determined by E-test. The VRE isolates were analyzed by PCR for vanA gene. Results: A total of 54 (81%) Enterococcus faecalis and 13 (19%) E. faecium were detected among the clinical isolates and 16 (24%) were VRE. The VRE isolates were multidrug resistant and linezolid resistance was also found to be in three. MIC range to vancomycin was 16-32 μg/ml among the VRE. The vanA gene was found in nine of 16 VRE isolates. Interpretation & conclusions: Emergence of VRE and presence of vanA in a tertiary care hospital setting in North-East India indicate toward a need for implementing infection control policies and active surveillance.
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Enterococcus spp. resistentes à vancomicina (ERV) têm emergido como um patógeno multirresistente relevante e de etiologia potencialmente letal nas infecções associadas à assistência em saúde ao redor do mundo. Este estudo pretende mostrar epidemiologia e características clínicas de pacientes com ERV em um hospital do sul do Brasil. Um estudo retrospectivo foi conduzido no período de janeiro de 2005 a novembro de 2007 no Hospital Universitário de Londrina. Todos os pacientes com cultura clínica com ERV foram identificados e seu prontuário médico revisado. A presença de colonização foi avaliada através de culturas de swab retal e a identificação das amostras clínicas foi realizada pelo método automatizado MicroScan®. A média de idade dos pacientes foi de 54 anos. Trato urinário (68,0%) e corrente sanguínea (23,8%) foram os sítios mais frequentes, e a UTI apresentou se como setor de maior ocorrência (49,2%) das culturas positivas. E. faecium foi a espécie predominante, em 82,8% dos casos. Os fatores de risco observados foram a duração da internação (média de 58,2 dias), uso de antimicrobianos prévios e realização de procedimento invasivos, como o uso de cateter venoso central, sonda vesical e ventilação mecânica. Medidas de controle e culturas de vigilância são imprescindíveis no controle da disseminação do ERV. Os resultados obtidos no presente trabalho contribuem para uma melhor compreensão da dinâmica epidemiológica das infecções e da disseminação do ERV no Hospital Universitário de Londrina.
Vancomycin-resistant Enterococci (VRE) have emerged as a relevant multidrug-resistant pathogen and potencially lethal etiology of healthcare associated infections worldwide. This study intends to show the epidemiology and clinical characteristics of patients with VRE in a Hospital in South Brazil. A retrospective study was conducted from January 2005 to November 2007. A total of 122 VRE were identified in this period at the University Hospital of Londrina. All patients with VRE clinical culture have identified and their medical records have reviewed. The presence of colonization was evaluated through rectal swab cultures, and the species identification of clinical samples was performed by automated method MicroScan®. The mean age of patients was 54 years. Urinary tract (68.0%) and blood (23.8%) were the most frequent sites, and ICU was the largest sector of occurrence (49.2%). E. faecium was the predominant species, in 82.8% of cases.The risk factors presents were length of hospitalization (mean 58.2 days), previous use of antimicrobials and invasive procedure, such as use of central venous catheter, urinary catheter and mechanical ventilation. Control barriers and surveillance cultures are essential to prevent the VRE spread. The results obtained in this study contribute to a better understanding of the epidemiological dynamics of infections and the spread of VRE in University Hospital of Londrina.
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Vancomycin-Resistant Enterococci , Risk Factors , Cross InfectionABSTRACT
BACKGROUND: A surveillance system for antibiotic resistance is well organized in both Japan and Korea; however, a comparative analysis by microorganism has not previously been conducted. METHODS: We compared the latest antibiotic resistance rates of medically important pathogens, such as Staphylococcus aureus, enterococci, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii, between Japan and Korea. Data were collected by JANIS (Japan Nosocomial Infections Surveillance) and KARMS (Korean Antimicrobial Resistance Monitoring System) from 2007-2012. RESULTS: In 2012, the proportions of oxacillin-resistant S. aureus, vancomycin-resistant Enterococcus faecium (VRE), cefotaxime-resistant E. coli, ceftazidime-resistant K. pneumoniae, imipenem-resistant P. aeruginosa, and imipenem-resistant A. baumannii were 53%, 0.4%, 16.6%, 2.9%, 18.5%, and 2% in Japan and 67%, 32%, 29%, 40%, 28%, and 70% in Korea, respectively. CONCLUSION: There were large differences in the frequencies of VRE, ceftazidime-resistant K. pneumoniae, and imipenem-resistant A. baumannii between Japan and Korea. A collaborative study to probe the differences in the antibiotic resistance rates between the two countries should be performed.
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Acinetobacter baumannii , Cross Infection , Drug Resistance, Microbial , Enterococcus faecium , Escherichia coli , Japan , Klebsiella pneumoniae , Korea , Methicillin-Resistant Staphylococcus aureus , Pneumonia , Pseudomonas aeruginosa , Staphylococcus aureusABSTRACT
Objective This article aims to provide mechanisms and recent developments of molecular biology pertaining to re-sistance of Enterococci,providing rapid approaches for detecting resistant strains.Methods This article reviewed recent lit-eratures on resistance of Enterococci and a systemic analysis was conducted.Results Common detecting methods include polymerase chain reaction (PCR),pulsed field gel electrophoresis (PFGE),multilocus sequence typing (MLST)and South-ern blot.There also exist less widely-used methods such as pyrosequencing and genechip technique,which may prove effi-cient in some aspects.Conclusion Every method has its advantages and disadvantages.This article discussed how to utilize these methods to achieve their maximum capabilities.
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BACKGROUND: Recently, the iNtRON VRE vanA/vanB real-time PCR (iNtRON; iNtRON Biotechnology, Korea) assay, a multiplex real-time PCR method, was introduced. In this prospective study, we compared the iNtRON assay with the Seeplex VRE ACE detection kit (Seeplex; Seegene, Korea), a conventional multiplex PCR assay. METHODS: A chromogenic agar-based culture, in which pre-selected vancomycin-resistant enterococci (VRE) was grown and subsequently plated on blood agar with vancomycin disks, was regarded as the reference method. A total of 304 consecutive rectal swab specimens were tested for VRE by culture and by iNtRON and Seeplex PCR assays. For the PCR assays, specimens were enriched for 16-24 hr before PCR. RESULTS: VRE were isolated from 44 (14.5%) specimens by chromogenic agar-based culture. The clinical sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the iNtRON assay were 100% (95% confidence interval: 89.8%-100%), 99.2% (96.9%-99.9%), 95.6% (83.6%-99.2%), and 100% (98.2%-100%), respectively, while those of the Seeplex assay were 97.7% (86.2%-99.9%), 99.6% (97.5%-99.9%), 97.7% (86.2%-99.9%), and 99.6% (97.5%-99.9%), respectively. The iNtRON assay had a detection limit of 3,159 copies/microL and 13,702 copies/microL for the vanA and vanB genes, respectively. No cross-reactivity was observed in 11 non-VRE bacterial culture isolates. CONCLUSIONS: The overall performance of the iNtRON assay was comparable to that of a chromogenic agar-based culture method for prompt identification of VRE-colonized patients in hospitals. This assay could be an alternative or supportive method for the effective control of nosocomial VRE infection.
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Humans , Bacterial Proteins/genetics , Bacterial Typing Techniques/methods , Carbon-Oxygen Ligases/genetics , DNA, Bacterial/metabolism , Gram-Positive Bacterial Infections/microbiology , Reagent Kits, Diagnostic , Real-Time Polymerase Chain Reaction , Vancomycin Resistance/genetics , Vancomycin-Resistant Enterococci/geneticsABSTRACT
BACKGROUND/AIMS: Liver transplant patients are at high risk for methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) colonization. We evaluated patients before and after liver transplant using active surveillance culture (ASC) to assess the prevalence of MRSA and VRE and to determine the effect of bacterial colonization on patient outcome. METHODS: We performed ASC on 162 liver transplant recipients at the time of transplantation and 7 days posttransplantation to monitor the prevalence of MRSA and VRE. RESULTS: A total of 142 patients had both nasal and rectal ASCs. Of these patients, MRSA was isolated from 12 (7.4%) at the time of transplantation (group 1a), 9 (6.9%) acquired MRSA posttransplantation (group 2a), and 121 did not test positive for MRSA at either time (group 3a). Among the three groups, group 1a patients had the highest frequency of developing a MRSA infection (p < 0.01); however, group 2a patients had the highest mortality rate associated with MRSA infection (p = 0.05). Of the 142 patients, VRE colonization was detected in 37 patients (22.8%) at the time of transplantation (group 1b), 21 patients (20%) acquired VRE posttransplantation (group 2b), and 84 patients did not test positive for VRE at either time (group 3b). Among these three groups, group 2b patients had the highest frequency of VRE infections (p < 0.01) and mortality (p = 0.04). CONCLUSIONS: Patients that acquired VRE or MRSA posttransplantation had higher mortality rates than did those who were colonized pre-transplantation or those who never acquired the pathogens. Our findings highlight the importance of preventing the acquisition of MRSA and VRE posttransplantation to reduce infections and mortality among liver transplant recipients.
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Adult , Female , Humans , Male , Middle Aged , Enterococcus/isolation & purification , Gram-Positive Bacterial Infections/diagnosis , Liver Transplantation/adverse effects , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Prevalence , Prospective Studies , Republic of Korea/epidemiology , Risk Factors , Staphylococcal Infections/diagnosis , Time Factors , Treatment Outcome , Vancomycin ResistanceABSTRACT
Introduction: Identification of patients with methicillin resistant Staphylococcus aureus (MRSA) and vancomycin resistant Enterococci (VRE) is essential to limit the spread of these agents, through the use of isolation and contact precautions. Traditional microbiology has a long turn around time (3-5 days) extending the time of isolation, increasing complexity and cost of these patients. Objectives: To implement a new real time polymerase chain reaction (PCR) GeneXpert R for SAMR and VRE detection. To compare costs and turn around time of PCR versus traditional cultures. Methods: Two periods were compared, in the first, traditional microbiology (standard group) was used, and in the second, only PCR was used (PCR group). Results: MRSA or VRE were identified in 29.9% of patients in the PCR group and in 9.6% in the standard group. Turn around time was 15 ± 9 hours in PCR group and 53 ± 23 hours in standard group. PCR group had a net cost of USD 245 per patient and standard group USD 530 per patient. Discussion: PCR technique GeneXpert R for MRSA and VRE had a positive impact in the management of these patients and justifies its inclusion.
Introducción: La identificación de pacientes con Staphylococcus aureus resistente a meticilina (SARM) y Enterococcus resistente a vancomicina (ERV), permite limitar su diseminación usando aislamiento en cohorte y precauciones de contacto. Los resultados de los cultivos microbiológicos demoran 3 a 5 días, lo que retrasa el retiro de las precauciones y agrega costos económicos. Objetivos: Implementar técnica de reacción de polimerasa en cadena en tiempo real (RPC), GeneXpert R, para SARM y ERV y comparar tiempos de respuesta y costos en relación al uso de microbiología convencional. Material y Métodos: Se compararon dos períodos, uno en que se usó solo RPC (grupo RPC) y otro histórico, en el que se usó microbiología tradicional (grupo estándar) Resultados: Se confirmó SARM y/o ERV en 29,9% de los pacientes del grupo RPC, y en 9,6% del grupo estándar. Los tiempos de respuesta fueron 15 ± 9 h (grupo RCP) y 53 ± 23 h (grupo estándar). Los costos directos por paciente fueron de USD 245 en el grupo RPC y de USD 530 en el grupo estándar. Discusión: La RPC en tiempo real, GeneXpert, para SAMR y ERV tuvo un alto impacto alto clínico que justifica su incorporación.
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Humans , Enterococcus/isolation & purification , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Patient Transfer , Real-Time Polymerase Chain Reaction/economics , Staphylococcal Infections/microbiology , Vancomycin Resistance , Enterococcus/drug effects , Real-Time Polymerase Chain Reaction/methods , Staphylococcal Infections/diagnosis , Staphylococcal Infections/economics , Time FactorsABSTRACT
Background & objectives: Enterococci are the leading cause of nosocomial infections, and are thus a persisting clinical problem globally. We undertook this study to determine the virulence factors and the antibiotic resistance in Enterococcus clinical isolates. Methods: One hundred and fifty Enterococcus isolates obtained from various clinical specimens were speciated biochemically and subjected to antibiotic susceptibility testing using Kirby-Bauer disk diffusion method. Resistance to vancomycin was determined by using agar screen method. Haemolysin and gelatinase productions were detected using 5 per cent sheep blood agar and 12 per cent gelatin agar, respectively. Results: Among the 150 Enterococcus isolates, 84 (56%) were E. faecalis. 51(34%) E. faecium, and 15 (10%) were other Enterococcus spp. Haemolysin production was seen among 123 (82%) isolates while 61 (40.6%) isolates produced gelatinase. Nearly 50 per cent of the isolates showed high level aminoglycoside resistance (HLAR). A total of 13 (8.6%) isolates showed vancomycin resistance, of which 11(7.3%) had an MIC >8 μg/ml. Interpretation & conclusions: Presence of VRE was found to be low among the isolates studied. However, occurrence of VRE along with HLAR calls for regular detection of vancomycin resistance promptly and accurately to recognize VRE colonization and infection. Early detection of VRE and HLAR along with their virulence trait will help in preventing the establishment and spread of multidrug resistant Enterococcus species.
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Background & objectives: Growing incidence of methicillin resistant Staphylococcus aureus (MRSA) and vancomycin resistant enteroccoci (VRE) is posing a therapeutic problem due to limited drug options. Therefore, the present study was undertaken to check susceptibility of MRSA and VRE isolates against new antimicrobials such as daptomycin and linezolid. Methods: A total of 586 Gram-positive isolates comprising 442 S. aureus and 144 enterococci isolated from hospitalized cases included in the study, were subjected to in vitro antimicrobial susceptibility testing by disc diffusion method. One hundred twenty four enterococci obtained from rectal swabs of neonates were also included. Minimum inhibitory concentration (MIC) was determined for daptomycin, linezolid, vancomycin and teicoplanin against 50 each isolates of MRSA and VRE by E strip. Results: Among the staphylococci, 326 (73.85%) isolates were MRSA. MIC for vancomycin and teicoplanin among MRSA was ≤3 μg/ml. MIC for daptomycin among MRSA was found to be in the range of 0.064-1.5 μg/ml. Percentage of VRE among clinical samples was 14.29 per cent while it was 47.06 per cent among enterococci from rectal swabs of neonates. MIC was >256 μg/ml for vancomycin among VRE and was associated with van A genotype. MIC range for daptomycin among VRE was 0.38-3 μg/ml. MIC for linezolid among MRSA and VRE was in the range of 0.25 to 1 and 0.38 -1.5 μg/ml, respectively. Interpretation & conclusions: The present study showed a rise in MIC to vancomycin for sizable number of MRSA and growing percentage of VRE at our centre. Daptomycin and linezolid showed 100 per cent activity against MRSA and VRE.
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Background: Vancomycin-resistant enterococci (VRE) are third leading cause of nosocomial infection. Therefore, an effective, accurate and early detection of VRE along with their minimum inhibitory concentrations (MICs) is required to initiate appropriate therapy and thus better patient outcome. Objective: To detect VRE by real time quantitative polymerase chain reaction (Q-PCR) and to compare the results with chrom ID (C-ID) VRE and PCR. Further the study also determined the fold change of vanA gene by Q-PCR in different groups of VRE isolates classified on the basis of glycopeptides MIC range. Subjects and Methods: A total of 145 (80 VRE and 65 vancomycin-susceptible enterococci) clinical isolates were included in the study. After the screening of VRE isolates MICs were determined by E-test and agar dilution method. Further VRE was confirmed by vanA and vanB specific PCR and Q-PCR. Results: The sensitivity and specificity of C-ID VRE was 100% and 95.38%. However, sensitivity and specificity of conventional and Q-PCR were found to be 100%. Conventional and Q-PCR confirmed that our all isolates were vanA type. Mean R value was significantly higher ( P < 0.001) in group I (MIC > 1024 μg/ml) when compared to group II (MIC 512-1024 μg/ml) and group III (MIC < 512 μg/ml) isolates. The mean R was also significantly higher in group II when compared to group III isolates ( P = 0.038). Conclusion: Q-PCR is a rapid technique to detect vanA in enterococci along with their MIC range, thus it might be helpful to decide the treatment modalities of infections caused by VRE.
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Vancomycin-resistant enterococci (VRE) are important hospital pathogens and have become increasingly common in patients admitted to the intensive care unit (ICU). To determine the incidence and the risk factors associated with VRE colonisation among ICU patients, active surveillance cultures for VRE faecal carriages were carried out in patients admitted to the ICU of the University Hospital of Uberlândia, Minas Gerais, Brazil. Risk factors were assessed using a case-control study. Seventy-seven patients (23.1 percent) were found to be colonised with vanC VRE and only one patient (0.3 percent) was colonised with vanA VRE. Independent risk factors for VRE colonisation included nephropathy [odds ratio (OR) = 13.6, p < 0.001], prior antibiotic use (OR = 5.5, p < 0.03) and carbapenem use (OR = 17.3, p < 0.001). Our results showed a higher frequency (23.1 percent) of Enterococcus gallinarum and Enterococcus casseliflavus, species that are intrinsically resistant to low levels of vancomycin (vanC), without an associated infection, associated with prior antibiotic use, carbapenem use and nephropathy as comorbidity. This study is the first to demonstrate the risk factors associated with vanC VRE colonisation in ICU hospitalised patients. Although vanA and vanB enterococci are of great importance, the epidemiology of vanC VRE needs to be better understood. Even though the clinical relevance of vanC VRE is uncertain, these species are opportunistic pathogens and vanC VRE-colonised patients are a potential epidemiologic reservoir of resistance genes.
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Humans , Anti-Bacterial Agents/pharmacology , Cross Infection/microbiology , Enterococcus/drug effects , Gram-Positive Bacterial Infections/microbiology , Vancomycin Resistance , Case-Control Studies , Critical Illness , Enterococcus/classification , Enterococcus/isolation & purification , Hospitals, University , Incidence , Intensive Care Units , Microbial Sensitivity Tests , Risk FactorsABSTRACT
Objective To study the vancomycin-resistant genes and the virulence factors genes in vancomycin-resistant Enterococci (VRE),and to analyze the drug-resistance character and epidemic characteristics of VRE strains and provide the basis for clincal selection of drugs and infection control.Methods VRE were screened by agar dilution sieving plate (ADSP) containing 6 μg/ml of vancomycin,drug resistance of VRE to other common antibiotics were detected by VITEK-60 automatic microbial analyzer.The gene types and virulence factor genes of VRE were determined by PCR.And the genetic relationships among VRE were determined by multilocus sequence typing.Results Seven vancomycin-resistant Enterococcus faecium strains were found in 360 enterococcus strains.All the VRE strains exhibited high-level vancomycin resistance ; some of them were medium or senstive to teicoplanin.They all carried vanA gene and esp gene and one of them carried 4 kinds of virulence factor genes.The ST type of the 7 VRE strains were diffused distribution.Conclusion We found vanB phenotype vanA genotype vancomycin-resistant Enterococcus faecium isolates in Wenzhou; these VRE strains were multidrug resistance and carried various virulence factor genes.Linezolid could be used as a recommend drug for treatment of VRE infection.The protection of antibiotics sensitivity should be strengthened.
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INTRODUCTION: Laboratory-based surveillance is an important component in the control of vancomycin resistant enterococci (VRE). METHODS: The study aimed to evaluate real-time polymerase chain reaction (RT-PCR) (genes vanA-vanB) for VRE detection on 115 swabs from patients included in a surveillance program. RESULTS: Sensitivity of RT-PCR was similar to primary culture (75 percent and 79.5 percent, respectively) when compared to broth enriched culture, whereas specificity was 83.1 percent. CONCLUSIONS: RT-PCR provides same day results, however it showed low sensitivity for VRE detection.
INTRODUÇÃO: Vigilância com base em detecção laboratorial é um componente importante no controle de enterococos resistentes a vancomicina (ERV). MÉTODOS: Avaliamos procedimento da reação em cadeia da polimerase real time (PCR-RT) (genes vanA-vanB) para detecção de ERV em 115 swabs de pacientes incluídos em um programa de vigilância. RESULTADOS: A sensibilidade do RT-PCR foi semelhante a da cultura primária (75 por cento e 79,5 por cento, respectivamente) quando comparada com a cultura em caldo enriquecido, enquanto a especificidade foi de 83,1 por cento. CONCLUSÕES: O RT-PCR fornece resultados no mesmo dia, contudo mostra baixa sensibilidade para a detecção de VRE.
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Humans , Bacterial Proteins/genetics , Carbon-Oxygen Ligases/genetics , Enterococcus/genetics , Gram-Positive Bacterial Infections/diagnosis , Rectum/microbiology , Vancomycin Resistance/genetics , Enterococcus/isolation & purification , Gram-Positive Bacterial Infections/microbiology , Predictive Value of Tests , Real-Time Polymerase Chain Reaction/methods , Sensitivity and SpecificityABSTRACT
INTRODUCTION: In the past two decades members of the genus Enterococcus have emerged as important nosocomial pathogens worldwide. This study prospectively analyzed the distribution of species and trends in antimicrobial resistance among clinical isolates of enterococci in a Brazilian tertiary hospital from 2006-2009. METHODS: Enterococcal species were identified by conventional biochemical tests. The antimicrobial susceptibility profile was performed by disk diffusion in accordance with the Clinical and Laboratory Standards Institute (CLSI). A screening test for vancomycin was also performed. Minimal inhibitory concentration (MIC) for vancomycin was determined using the broth dilution method. Molecular assays were used to confirm speciation and genotype of vancomycin-resistant enterococci (VRE). RESULTS: A total of 324 non-repetitive enterococcal isolates were recovered, of which 87 percent were E. faecalis and 10.8 percent E. faecium. The incidence of E. faecium per 1,000 admissions increased significantly (p < 0.001) from 0.3 in 2006 to 2.3 in 2009. The VRE rate also increased over time from 2.5 percent to 15.5 percent (p < 0.001). All VRE expressed high-level resistance to vancomycin (MIC >256µg/ mL) and harbored vanA genes. The majority (89.5 percent) of VRE belonged to E. faecium species, which were characteristically resistant to ampicillin and quinolones. Overall, ampicillin resistance rate increased significantly from 2.5 percent to 21.4 percent from 2006-2009. Resistance rates for gentamicin, chloramphenicol, tetracycline, and erythromycin significantly decreased over time, although they remained high. Quinolones resistance rates were high and did not change significantly over time. CONCLUSIONS: The data obtained show a significant increasing trend in the incidence of E. faecium resistant to ampicillin and vancomycin.
INTRODUÇÃO: Nas últimas duas décadas, os enterococos emergiram como importantes patógenos nosocomiais no mundo inteiro. Neste estudo, foi analisada a distribuição das espécies e a evolução da resistência aos antimicrobianos entre isolados clínicos de enterococos obtidos em um hospital terciário, no período de 2006 a 2009. MÉTODOS: As espécies foram identificadas por testes bioquímicos convencionais e o perfil de sensibilidade foi determinado pelo método de disco difusão. A sensibilidade à vancomicina foi também determinada pela triagem em agar e pela concentração inibitória mínima (CIM). Testes moleculares foram utilizados para confirmar as espécies e determinar os genótipos dos enterococos resistentes à vancomicina (VRE). RESULTADOS: Foram analisadas 324 amostras de enterococos, sendo 87 por cento E. faecalis e 10,8 por cento E. faecium. A incidência de E. faecium por 1.000 pacientes internados aumentou significativamente (p < 0,001) de 0,3 em 2006 para 2,3 em 2009. A taxa de VRE também aumentou significativamente de 2,5 por cento para 15,5 por cento (p < 0,001). Todos os VRE apresentaram genótipo VanA e CIM >256µg/mL para vancomicina. A maioria (89,5 por cento) dos VRE pertencia à espécie E. faecium e foram resistentes à ampicilina e quinolonas. Foi observado um aumento significativo na taxa de resistência à ampicilina, de 2,5 por cento (2006) para 21,4 por cento (2009). As taxas de resistência para gentamicina, cloranfenicol, tetraciclina e eritromicina diminuíram significativamente no período do estudo. Para as quinolonas, as taxas de resistência foram elevadas não alteraram significativamente, no período do estudo. CONCLUSÕES: Os resultados do presente estudo mostram um aumento significativo na incidência de E. faecium resistentes à ampicilina e vancomicina.