Prevalence and Molecular Epidemiology of Vancomycin-Resistant Enterococci (VRE) Strains Isolated from Animals and Humans in Korea

Abstract

BackgroundTo assess the possibility of VRE transmission from animals to humans, we studied the prevalence of vancomycin-resistant enterococci (VRE) in farm animals, raw chicken meat, and healthy people. We then determined the molecular relatedness of VRE isolates between animals and humans in Korea.MethodsWe aimed to isolate VRE from 150 enterococci specimens of farm animals, 15 raw chicken meat samples, and stools from 200 healthy people. Species differentiation was done with conventional biochemical tests. Vancomycin resistance genotyping was done by polymerase chain reaction (PCR). Using the agar dilution method, antimicrobial susceptibility was tested for 8 antimicrobials and pulsed-field gel electrophoresis (PFGE) was done to evaluate the molecular relatedness of VRE isolates.ResultsThe prevalence of VRE was 14.7% (22/150) in farm animal specimens, 1% (2/200) in healthy people, and 60% (9/15) in raw chicken meat. Of 22 animal VRE isolates, 1 vanA E. faecium, 15 vanC1 E. gallinarum, and 6 vanC2 E. casseliflavus were identified. All of the 9 VRE from raw chicken meat and all of the 20 clinical VRE strains were vanA E. faecium. However, in healthy people, only 2 vanC2 E. casseliflavus were isolated. These showed low-level resistance to vancomycin and susceptibility to teicoplanin. However, 9 VRE strains from raw chicken meat had high-level resistance to vancomycin (MIC50,90: >128 µg/mL), teicoplanin (MIC50,90: >128 µg/mL), ampicillin (MIC50,90: >128 µg/mL), erythromycin (MIC50,90: >128 µg/mL), and tetracycline (MIC50,90: 128/>128 µg/mL).ConclusionThis study demonstrated little evidence of VRE colonization in healthy people despite high recovery of VRE among raw chicken meat. It is suggested that there is little evidence of VRE transmission from animals to healthy people. However, we assumed that there exists the possibility of VRE contamination during the processing of chicken meat.

Antimicrobial Resistance of Enterococci Isolated from Mastitic Bovine Milk Samples in Korea

“…In Korea, the glycopeptides antibiotic, avoparcin was widely used as a growth promoter for poultry and swine from 1983 to 1997, and vancomycin‐resistant enterococci (VRE) was first isolated from a leukaemia patient in 1992 (Park et al., 1992). Since then, VRE have been constantly recovered from patients in numerous hospitals (Kwon et al., 2000; Yang et al., 2007) and even in healthy people (Song et al., 2005). Moreover, VRE have been isolated from various animal sources in Korea, although most of them exhibited inherent low‐level resistance (Seo et al., 2005; Jung et al., 2007).…”

Trends and Significance of VRE Colonization in the ICU: A Meta-Analysis of Published Studies

“…Among these drug resistant pathogens, vancomycin-resistant enterococci (VRE) account for significant excess morbidity and costs [4-6]. Interestingly, VRE is uncommon (<1%) among otherwise healthy individuals [7,8], but it is present in most ICUs. Moreover, ICUs are major reservoirs of VRE that sustain VRE presence in the health care setting [9].…”

Antimicrobial Resistance and Multilocus Sequence Typing of Vancomycin-ResistantEnterococcus faeciumIsolated from the Chungcheong Area

“…Since then, they have been spread around the world and became an important nosocomial pathogen [1]. In Korea, VRE were first reported in 1992 and the number of isolates was limited so far.…”