Antibiotic resistance and multilocus sequence typing of Enterococcus faecium strains isolated from children under 3 years old in Sui county, Henan province

Abstract

Objective To investigate the antibiotic resistance, virulence genes, and sequence types of Enterococcus faecium (E.faecium) strains isolated from children under 3 years old in Sui county, Henan province. Methods Kirby-Bauer antibiotic testing was performed to analyze the antibiotic sensitivities of E. faecium strains to 15 common antibiotics. PCR analysis was used to detect the virulence genes carried by the E. faecium strains. Multilocus sequence typing (MLST) was performed for the typing of E. faecium strains. Results Forty-seven E. faecium strains were isolated from 120 stool samples collected from children under 3 years old in Sui county, Henan province, of which 95.7% were antibiotic-resistant strains. Most of the isolated E. faecium strains were resistant to rifampicin, accounting for 91.5% (43/47) of all isolates, followed by those resistant to erythromycin and tetracycline, which accounted for 68.1% (32/47). Moreover, high resistance rates to those antibiotics commonly used in clinical treatments of E. faecium infection including β-lactam and aminoglycosides antibiotics were observed. Those strains resistant to more than three kinds of antibiotics belonged to the same clonal complex including 12 strains of clonal complex 17 (CC17) harboring the virulence gene of hyl. All of the isolated E. faecium strains were susceptible to vancomycin, linezolid, chloromycetin and nitrofurantoin. Conclusion The E. faecium strains isolated from children under 3 years old in Sui county, Henan province were multi-antibiotic resistant. There were drug-resistance strains belonging to the CC17 and carrying the virulence gene of hyl. Key words: Enterococcus faecium; Antibiotic resistance; Virulence gene; Multilocus sequence typing