Antimicrobial Resistance of Enterococcal Isolates from Blood and Risk Factors for Vancomycin Resistant Enterococcal Bacteremia in a Tertiary Care University Hospital from 2003 to 2007 / 대한임상미생물학회지

BACKGROUND: In Korea, a sudden increase in vancomycin-resistant enterococci (VRE) infection has been noted since the late 1990s. This study was conducted to describe the antimicrobial resistances of enterococcal blood isolates and to identify risk factors associated with VRE bacteremia in a tertiary care university hospital over a recent five-year period. METHODS: This study was conducted to analyze the antimicrobial susceptibilities of enterococcal blood isolates by year from January 2003 to December 2007. Multivariate logistic regression analysis was used to investigate factors associated with VRE bacteremia. RESULTS: A total of 225 enterococcal strains (44.7% Enterococcus faecalis, 42.4% Enterococcus facium, 5.9% Enterococcus casseliflavus, and 4.7% Enterococcus gallinarum) were detected in blood, 55 of which (21.6%) were resistant to vancomycin. In 2004 and 2005, the resistance rates for vancomycin and teicoplanin (33.3% and 27.3%; 34.4% and 23.0%, respectively) increased. In 2003, 2006, and 2007, the resistance rates for vancomycin and teicoplanin (8.7% and 8.7%; 19.0% and 14.3%; 13.5% and 11.5%, respectively) decreased relative to those of the previous years. When 55 patients with VRE bacteremia were compared with 55 patients with vancomycin-susceptible enterococcal bacteremia using multivariate analysis, E. faecium bacteremia (OR 12.624, P<0.001) and enterococcal bacteremia caused by species other than E. faecium and E. faecalis (OR 21.473, P=0.011) were found to be statistical risk factors. Among several infection control activities, the restricted uses of vancomycin and quinupristin-dalfopristin decreased the vancomycin resistance rate from 27.78% to 15.50% (P=0.0257). CONCLUSION: VRE bacteremia would be effectively controlled via infection control activities based on studies regarding risk factors associated with VRE bacteremia.

Risk Factors of Nosocomial Infections Caused by Vancomycin-resistant Enterococcus / 中华医院感染学杂志

OBJECTIVE To investigate the risk factors for vancomycin-resistant Enterococcus(VRE) infections and their effective isolation measures.METHODS The data of 21 cases of VRE nosocomial infections were analyzed from Jul 2003 to Dec 2005 in Beijing Chaoyang Hospital;28 cases of antibiotic-sensitive Enterococcus infection were randomized as control.T test,chi-square test and Logistic regression analysis were used for statistics.Strict measures were taken to all of the VRE infected patients.RESULTS According to univariate analysis,the factors associated with the development of VRE nosocomial infection were age,in ICU,accepted invasive operation,Acute Physiology and Chronic Health Evaluation Ⅱ(APACHEⅡ),live in hospital more than 30 days,co-infection with other pathogens,and fluoroquinolone and vancomycin/norvancomycin use 15 days before isolation of VRE.Multivariate Logistic regression analysis identified two independent factors: accepted invasive operation and previous vancomycin/norvancomycin use.Spreading of VRE had not occurred.CONCLUSIONS Accepted invasive operation and previous vancomycin/norvancomycin use are independent risk factors for VRE infection.Effective measures can prevent the spread of VRE.

Antimicrobial Resistance of Staphylococcus aureus among Patients with Vancomycin Resistant Enterococcus / 감염과화학요법

BACKGROUND: The transfer of vancomycin resistance from vancomycin-resistant enterococci (VRE) to Staphylococcus aureus has been predicted. The purpose of this study is to determine the prevalence and antibiotics resistance of S. aureus among patients colonized with VRE. METHODS: Between January 2001 and December 2001, a prospective study was performed at Pusan National University Hospital on 27 patients. Surveillance swabs from nasal cavity, axilla, perineum, and rectum were obtained at weekly intervals. Methicillin susceptability of S. aureus was determined by oxacillin disk diffusion test and minimum inhibitory concentration (MIC) for vancomycin by microdilution broth test. RESULTS: Total of 292 swab cultures were performed and 67 S. aureus isolates were collected. 64 isolates (95.5%) were resistant to methicillin. The prevalence of nasal MRSA carrier in 19 patients colonized with VRE was higher than that in 8 patients not colonized with VRE (58% vs. 37.5%). In 64 MRSA isolates, MIC (microgram/mL) for vancomycin ranged from 0.5 to 2. No isolates with MIC >2 microgram/mL were observed. MIC of 1 microgram/mL was shown (observed) in 54 isolates, 2 microgram/mL in 6 isolates, and 0.5 microgram/mL in 4 isolates. CONCLUSION: The prevalence of S. aureus with colonization of VRE is higher than that without colonization of VRE. Most of S. aureus isolates were resistant to methicillin. VRSA isolates were not observed.

Antimicrobial Resistance of Staphylococcus aureus among Patients with Vancomycin Resistant Enterococcus / 감염과화학요법

BACKGROUND: The transfer of vancomycin resistance from vancomycin-resistant enterococci (VRE) to Staphylococcus aureus has been predicted. The purpose of this study is to determine the prevalence and antibiotics resistance of S. aureus among patients colonized with VRE. METHODS: Between January 2001 and December 2001, a prospective study was performed at Pusan National University Hospital on 27 patients. Surveillance swabs from nasal cavity, axilla, perineum, and rectum were obtained at weekly intervals. Methicillin susceptability of S. aureus was determined by oxacillin disk diffusion test and minimum inhibitory concentration (MIC) for vancomycin by microdilution broth test. RESULTS: Total of 292 swab cultures were performed and 67 S. aureus isolates were collected. 64 isolates (95.5%) were resistant to methicillin. The prevalence of nasal MRSA carrier in 19 patients colonized with VRE was higher than that in 8 patients not colonized with VRE (58% vs. 37.5%). In 64 MRSA isolates, MIC (microgram/mL) for vancomycin ranged from 0.5 to 2. No isolates with MIC >2 microgram/mL were observed. MIC of 1 microgram/mL was shown (observed) in 54 isolates, 2 microgram/mL in 6 isolates, and 0.5 microgram/mL in 4 isolates. CONCLUSION: The prevalence of S. aureus with colonization of VRE is higher than that without colonization of VRE. Most of S. aureus isolates were resistant to methicillin. VRSA isolates were not observed.