Genotyping of Staphylococcus epidermidis strains isolated from nosocomial infections by Multilocus Sequence Typing (MLST)

Subject Areas : Molecular Microbiology

Sara Rafiee ¹ (MS.c., Department of Microbiology, Shahrekord branch, Islamic Azad University, Shahrekord, Iran.)
Elahe Tajbakhsh ² (Associated Professor, Department of Microbiology, Shahrekord branch, Islamic Azad University, Shahrekord, Iran.)
Hassan Momtaz ³ (Professor, Department of Microbiology, Shahrekord branch, Islamic Azad University, Shahrekord, Iran.)

Received: 2016-09-22 Accepted : 2016-11-28 Published : 2017-01-01

Keywords: Staphylococcus epidermidis, Genetic clones, Multilocus Sequence Typing (MLST), Housekeeping genes,

Abstract :

Background & Objectives: Staphylococcus epidermidis is one of the main causes of urinary tract infections and second cause of respiratory infections in human. The aim of this study was genotyping S. epidermidis strains isolated from nosocomial infections and detection of genetic clones using Multilocus Sequence Typing (MLST) method. Materials & Methods: In this cross-sectional study, 16 S. epidermidis isolates were selected and PCR products from amplification of seven housekeeping genes were sequenced. The nucleotide sequences of each gene in each isolate were analyzed in the MLST database and, besides identifying different clones, gene - specific alleles in each sequence types (ST) were determined. Results: A total of 3 clones including ST22, ST88 and ST153 were identified from 16 isolates, which was classified into two gene clusters of A and B. ST22 clone with a frequency of 50%, ST88 with 31.25% and ST153 with 18.75% were identified. The most dominant S. epidermidis clone isolated in 16 isolates is ST22. Conclusion: Dendrogram analysis of the isolates showed the homology of all isolates to alleles previously reported. Furthermore, our results suggest the genetic diversity of the isolates.

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