Methicillin and Inducible Clindamycin-Resistant Staphylococcus aureus Isolated from Postoperative Wound Samples

Abstract

The present study aimed to investigate the incidence of Methicillin-Resistant Staphylococcus aureus strains (MRSA) and inducible clindamycin resistant S. aureus (ICRSA) among postoperative wound infected patients. A total of 94 S. aureus strains were isolated by conventional laboratory methods from 135 swab samples collected from post-operative wound infected patients in Khartoum State hospitals. The isolated strains were screened for MRSA by using cefoxitin disc. ICRSA strains was detected by D-test and their susceptibility to antimicrobial agents was done by modified Kirby-Bauer’s disc diffusion method. Ninety-four S. aureus isolates were screened for MRSA strains, we found 42 (45%) of isolates were MRSA and 52 (55%) of strains were methicillin-sensitive S. aureus (MSSA) phenotype. The incidence of ICRSA, constitutive clindamycin resistant (CCRSA) and erythromycin resistant (ERSA) strains among S. aureus isolates were 15.9% (15/94), 9% (8/94) and 2.12% (2/94), respectively. ICRSA resistant strains were slightly more frequent among MRSA, when compared with MSSA strains (16.67% (7/42) vs. 15.38% (8/52)). In addition, 33% of ICRSA strains were found resistant to both co-trimoxazole and gentamicin, while, 23% of strains were resistant to vancomycin. This study concluded that MRSA strains was nearly accounted a half of clinical isolates, which need more attention by improving hospitals environment heath quality. ICRSA isolates were detected within both MRSA and MSSA strains and the D test must be implemented as routine susceptibility test to avoided clindamycin treatment failure.

Keywords

• staphylococcus aureus
• wound
• mrsa
• inducible clindamycin
• d-test