Constitutive and Inducible Clindamycin Resistance Frequencies among Staphylococcus sp. Coagulase Negative Isolates in Al-Basrah Governorate, Iraq

Background: Antibiotics called macrolide, lincosamide and streptogramin B (MLSB) are being used to treat staphylococci infections. Multiple pathways that impart resistance to MLSB antibiotics have been confirmed to cause clinical failure. The present work aimed to determine the frequency of constitutive and inducible clindamycin resistant among coagulase-negative staphylococci (CoNS) isolates of different clinical samples in Al-Basrah governorate, Iraq. Methods: The ۲۸ CoNS, traditional techniques and the Vitek®۲ system were used to identify the isolates. The disk diffusion technique was used to detect methicillin resistance and antibiotic sensitivity patterns via cefoxitin, gentamicin, ciprofloxacin, amikacin, teicoplanin, linezolid, doxycycline and vancomycin disks. Erythromycin and clindamycin antibiotic disks was used to detect the inducible and constitutive clindamycin resistance as well as a D-test according to CLSI guidelines. Results: Among ۲۸ CoNS isolated, the Staphylococcus aureus ۱۱(۳۹.۲۹%), Staphylococcus epidermidis ۷(۲۵ %), Staphylococcus haemolyticus ۴(۱۴.۲۹%) and Staphylococcus saprophyticus ۳ (۱۰.۷۱%) were predominant isolated species. Out of ۲۸ CoNS isolates, ۱۵(۵۳.۵۷%) were methicillin resistant coagulasenegative staphylococci (MRCoNS) isolates and ۱۳(۴۶.۴۳%) were methicillin sensitive coagulase-negative staphylococci (MSCoNS) isolates. The ۱۵(۵۳.۵۷%) isolates out of ۲۸ CoNS, showed erythromycin resistance while ۶(۴۰%) isolates out of ۱۵ CoNS, showed inducible macrolide-lincosamide-streptogramin B (iMLSB) and ۲(۱۳.۳%) of CONS isolated showed constitutive macrolide-lincosamide-streptogramin B (cMLSB). Conclusions: In order to achive the best result in choosing the suitable treatment and avoiding the loses the money and time, it is better to use the D-test for inducible clindamycin resistance in the daily routine work of antibiotic susceptibility testing in hospital and private clinical laboratories.