Use of the d-test method for detection of inducible clindamycin resistance in staphylococci isolates

Abstract EN

Background and objective: The resistance to antimicrobial agents among Staphylococci is an increasing problem.

This has led to renewed interest in the usage of Macrolide-Lincosamide-Streptogramin B (MLSB) antibiotics to treat Staphylococcus aureus infections.

Clindamycin resistance in Staphylococcus species can be either constitutive or inducible which can lead to therapeutic failure.

In vitro routine tests for clindamycin susceptibility may fail to detect inducible clindamycin resistance thus necessitating the need to detect such resistance by a simple D test on routine basis.

Methods: Between October 2009-March 2010, 36 isolates of Staphylococci spp.

were recovered from 130 urine samples of children with UTI at Rapareen Pediatric Hospital in Erbil city.

All the Staphylococcal spp.

were identified by using standard microbiological procedures [4].

All isolates were tested for inducible clindamycin resistance by the D-zone test.

Results: Out of 36 isolates of Staphylococci spp.16 isolates were Staphylococcus aureus (56.3% MRSA, 43.8% MSSA) and 20 were coagulase negative Staphylococci.

Inducible clindamycin resistance was demonstrated in 33.3% of methicillin resistance Staphylococcus aureus (MRSA), 14.3% in methicillin sensitive Staphylococcus aureus (MSSA) and 35% in coagulase negative Staphylococci.

Conclusions: This study indicates importance of the D-zone test in detecting inducible clindamycin resistance in staphylococci to aid in the optimal treatment of patients.