Abstract :
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 28 CoNS, traditional techniques and the Vitek®2 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 28 CoNS isolated, the Staphylococcus aureus 11(39.29%), Staphylococcus epidermidis
7(25 %), Staphylococcus haemolyticus 4(14.29%) and Staphylococcus saprophyticus 3 (10.71%) were
predominant isolated species. Out of 28 CoNS isolates, 15(53.57%) were methicillin resistant coagulasenegative
staphylococci (MRCoNS) isolates and 13(46.43%) were methicillin sensitive coagulase-negative
staphylococci (MSCoNS) isolates. The 15(53.57%) isolates out of 28 CoNS, showed erythromycin
resistance while 6(40%) isolates out of 15 CoNS, showed inducible macrolide-lincosamide-streptogramin
B (iMLSB) and 2(13.3%) 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.
