Full Length Research Paper

Identification and determination of coagulase-negative Staphylococci species and antimicrobial susceptibility pattern of isolates from clinical specimens

Ahmad Farajzadeh Sheikh* and Manijeh Mehdinejad

Department of Microbiology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences (AJUMS), Ahvaz, Iran.

*Corresponding author. E-mail: [email protected]. Tel: +98-611- 3738154. Fax: +98-611-3332036.

Accepted 19 September, 2011

Abstract

Coagulase negative Staphylococci (CoNS) are the important agents in nosocomial infection. Recently, resistant of CoNS against antimicrobial agents is increasing. The aim of this study is determination of species of CoNS, and antimicrobial susceptibility pattern of species obtained from clinical specimens. Clinical specimens from different organism were collected. Laboratory tests included: culture, Gram stain, coagulase test, biochemistry tests, and antimicrobial susceptibility pattern were performed by standard methods. 201 Staphylococci were isolated from varying infected organ, of which 134(66.7%) were identified as proven CoNS that distributed among 16 species. The majority of species of CoNS was Staphylococcus epidermidis (19.4%) and the lowestStaphylococcus auricularis ( ,(0.74Staphylococcus caprae (0.74%) and Staphylococcus intermedius (0.74%). Also majority of CoNS related to organ was obtained from urine specimens (51.5%). The antimicrobial susceptibility patterns showed that the most resistant of the CoNS belonged to oxaciline (94.02%) and least resistant belong to vancomycine (20.89%). Among of the CoNS species, S. epidermidis (96.15%) have had higher resistant to oxacillin. S. epidermidis had the highest frequency among the CoNS which were isolated from clinical specimens, and majority of CoNS were isolated from urine specimens, the higher resistant of CoNS belonged to oxaciline and the lowest to vancomycine.

Key words: Coagulase negative Staphylococci (CoNS), antimicrobial susceptibility pattern, clinical specimens.