Molecular Characterization and Resistant Spectrum of Enterococci Isolated from a Haematology Unit in China

Abstract

Objectives: The present study screened clinical isolates of E. faecalis and E. faecium to determine resistant spectrum and the potential virulence genes characterization among them of haematology patients.

Methods: Clinical Enterococci isolates were obtained from a haematology unit in a tertiary care hospital in China.

Results: Among 125 isolates available for the investigation, 46 were identified as E. faecium, and 79 were E. faecalis. Urine was the most common source (82, 65.6%). E. faecium isolates were more resistant than E. faecalis. Among E. faecium, maximum resistance was seen against PEN 93.5% and AMP 93.5% followed by CIP 87%. Eight vancomycin-resistant E. faecium (VREfm) isolates were obtained, positive for vanA genotype. Of 125 Enterococci isolates, 67(53.6%) were acm, and 42.4%, 25.6%, 25.6%, 24.8%, 23.2%, 20.8%, 10.4% and 7.2% of isolates were positive for esp, cylL-A, asa 1, cylL-S, cpd, cylL-L, gel-E and ace, respectively. E. faecalis isolates have more virulence genes (VGs) than E. faecium. MLST analysis of VREfm identified three different STs (ST17, ST78 and ST203).

Conclusion: The study provides the molecular characterization and resistant spectrum of Enterococci isolated from a haematology unit in China. Molecular analysis showed that all VREfm isolates belonged to pandemic clonal complex-17(CC17), associated with hospital-related isolates. Therefore, determining resistant spectrum and virulence characterization is crucial for the prevention and control of the spread of nosocomial infections caused by Enterococci in the haematology unit.

Keywords: Molecular analysis; Nosocomial infections; Vancomycin-resistant Enterococci.

[Table/Fig-3]:

Agarose gel electrophoresis of amplified vanA gene. Lane M: D2000 DNA Marker(100, 250, 500, 750, 1000, and 2000bp); Lanes 1-6, 8-9: Isolates positive for the vanA genes; Lane 10: positive control.