Abstract:
Aims S. haemolyticus is generally considered an opportunistic pathogen that is strongly
associated with immunocompromised individuals. S. haemolyticus is ranked as a highly
antibiotic-resistant pathogen for various types of antibiotics. Current study aimed to
investigate the frequency of inducible clindamycin resistance in S. haemolyticus isolated from
surgical wounds infections using D-test and molecular methods in Al-Basrah, Iraq.
Materials & Methods 200 surgical wound swabs were collected from Ports General Hospital
in Basrah, Iraq. The coagulase-negative staphylococcal strains were identified using methods
like oxidase, catalase, hemolysis, and coagulase tests and confirmed by Vitek®2 system.
Methicillin resistance and inducible clindamycin resistance were detected according to disk
diffusion method based on CLSI guidelines. Moreover, molecular approaches was performed
to confirm methicillin and inducible clindamycin resistance results.
Findings Out of 200 cases, 75 surgical wound swabs (37.5%) showed positive bacterial
cultures. The highest frequency of isolates belonged to Pseudomonas aeruginosa (25.3%),
Staphylococcus epidermidis (17.3%), Staphylococcus aureus (14.7%) and Escherichia coli
(13.3%), respectively. Out of eight S. haemolyticus isolates, only 5 isolates (62.5%) showed
inhibitory resistance criteria for both oxacillin and cefoxitin. Furthermore, 3 S. haemolyticus
isolates (37.5%) were erythromycin-resistant and clindamycin sensitive with D-test positive
with iMLSB resistance phenotype. While 2 isolates (25.0%) showed cMLSB resistance
phenotype and 3 (37.5%) isolates were shown MSB resistance phenotypes. The most frequent
resistance genes of S. haemolyticus strains were mecA (62.5%), ermA (62.5%), ermB (50.0%),
respectively.
Conclusion D-test and molecular technique are appropriate for detection of inducible
clindamycin resistance in S. haemolyticus strains.