Ankit Belbase
Department of Microbiology, Nepal
Title: Detection of Inducible Clindamycin Resistance and Biofilm Production among Staphylococcus aureus Isolates from the Clinical Specimens
Biography
Biography: Ankit Belbase
Abstract
Background The increasing emergence of antibiotic resistance by Staphylococcus aureus is a global problem. Its ability for biofilm formation has further exaggerated the resistance capacity.The main objective of this study was to ascertain the frequency, distribution and antimicrobial susceptibility pattern of S. aureus. Also, Inducible Clindamycin resistance and biofilm production in S. aureus isolates was observed.
Methods This cross-sectional study was conducted in B & B Hospital Gwarko Lalitpur, through March 2015 to September 2015. Specimens were processed by standard techniques. Antimicrobial susceptibility testing was done by modified Kirby-Bauer disc-diffusion method. MRSA was detected by cefoxitin disc diffusion method and Oxacillin agar dilution method. Detection of inducible clindamycin resistance was assessed by D-test whereas biofilm was detected by Congo Red Agar and Microtitre Plate method.
Results A total of 76 (9.15%, N=830) S. aureus were obtained during the study period, out of
which 47.4% (36/76) were methicillin-resistant (MRSA). Inducible clindamycin resistance was found in 22.4% (17/76) of isolates;MRSA constituted 88.2% (15/17) of those isolates. Tetracycline, tigecycline and chloramphenicol were highly effective in vitro with resistance rate 1.3% (1/76), 2.6% (2/76) and 5.3% (4/76) respectively. In contrast, penicillin G faced greater resistance, 97.4% (74/76) resistance followed by ciprofloxacin, cotrimoxazole, and erythromycin with resistance rate of 72.4% (55/76), 63.1% (48/76) and 55.3% (42/76) respectively. A total of 45 (59.21%)isolates were obtained multidrug resistant (MDR).Microtitre Plate method revealed more biofilm producers (46.1%, 35/76) in comparison to Congo Red Agar method (38.2%, 29/76). Among MRSA 5.6% (2/36), 16.7% (6/36), 41.7% (15/36) were strong, moderate and weak biofilm producer respectively.
Conclusions This study reveals the high rate of MRSA infection and having the ability of biofilm formation is an alarming for public health.
Key words Biofilm, D-test, Inducible clindamycin resistance, MRSA