This study investigated the aminoglycoside resistance phenotypes and genotypes, as well as the prevalence of virulence genes, in
Enterococcus species isolated from clinical patients in China. A total of 160
enterococcal isolates from various clinical samples collected from September 2013 to July 2014
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This study investigated the aminoglycoside resistance phenotypes and genotypes, as well as the prevalence of virulence genes, in
Enterococcus species isolated from clinical patients in China. A total of 160
enterococcal isolates from various clinical samples collected from September 2013 to July 2014 were identified to the species level using the VITEK-2 COMPACT system. The antimicrobial susceptibilities of the identified
Enterococcus strains were determined by the Kirby-Bauer (K-B) disc diffusion method. PCR-based assays were used to detect the aminoglycoside resistance and virulence genes in all
enterococcal isolates. Of 160
Enterococcus isolates, 105 were identified as
E. faecium,
35 as
E. faecalis, and 20 isolates were classified as “other”
Enterococcus species. High-level aminoglycoside resistance (HLAR) for gentamicin, streptomycin, and both antibiotics was identified in 58.8, 50, and 34.4% of strains, respectively. The most common virulence gene (50.6% of isolates) was
efaA, followed by
asa1 (28.8%). The most prevalent aminoglycoside resistance genes were
aac(6')-Ie-aph(2''),
aph(2')-Id,
aph(3')-IIIa, and
ant(6')-Ia, present in 49.4%, 1.3%, 48.8% and 31.3% of strains, respectively. Overall,
E. faecium and
E. faecalis were most frequently associated with hospital-acquired enterococcal infections in Zhejiang Province. All aminoglycoside resistance genes, except
aph(
2'')
-Id,
were significantly more prevalent in HLAR strains than amongst high level aminoglycoside susceptible (HLAS) strains, while there was no significant difference between HLAR and HLAS strains in regard to the prevalence of virulence genes, apart from
esp, therefore, measures should be taken to manage infections caused by multi-drug resistant
Enterococcus species.
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