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Volume 44, Number 1, February 2011

Determination of antimicrobial susceptibility patterns and inducible clindamycin resistance in Staphylococcus aureus strains recovered from southeastern Turkey


Fahriye Eksi, Efgan Dogan Gayyurhan, Aysen Bayram, Tekin Karsligil


Received: October 20, 2009    Revised: December 1, 2009    Accepted: January 13, 2010   

 

Corresponding author:

Department of Clinical Microbiology, School of Medicine, Gaziantep University, Universite Bulvari 27310,
Gaziantep, Turkey.
E-mail address: eksi@gantep.edu.tr (F. Eksi).



 

Background and purpose: 

In this study, we determined the susceptibility patterns of Staphylococcus aureus strains to various antimicrobials and prevalence of inducible clindamycin resistance (ICR) in these isolates.



 

Methods:

Two hundred and one S aureus strains, isolated from various clinical samples, were included in the study. Antibiotic susceptibilities were studied by disc diffusionmethod on the basis of theguidelines by theClinical andLaboratory Standards Institute.Thediscdiffusioninductiontest (D test) was applied to determine ICR resistance among erythromycin-resistant S aureus isolates.



 

Results:

Of the 201 S aureus strains, 101 (50.2%) were resistant to methicillin. All strains were susceptible to vancomycin, teicoplanin, quinupristin/dalfopristin, and linezolid. It was found that 54 (53.4%)methicillin-resistant S aureus (MRSA) strainswere erythromycin resistant, and 40 (39.6%) of themshowed constitutive clindamycin resistance. ICRwasdetectedin seven(6.9%)MRSAstrains. It was found that 13 (13.0%)methicillin-susceptibleSaureus (MSSA) strainswereerythromycinresistant. Constitutive clindamycin resistance was seen in one (1.0%) MSSA strain, and ICRwas detected in 10 (10.0%) cases.



 

Conclusion:

There was a high rate of methicillin resistance among S aureus strains in our hospital. However, no statistically significant difference of ICRwas observed betweenMRSA andMSSA strains (pZ0.434) or between inpatients and outpatients (pZ0.804). Itwas concluded that ICR should be routinely evaluated in each S aureus case to avoid therapy failure among patients.



 

Key words:

Antibiotic susceptibility; Inducible clindamycin resistance; Staphylococcus aureus