Antibacterial activity of penicillins alone and in combination with different agents against Staphylococcus aureus.

Difficulties in the treatment of the resistant strains of Staphylococcus aureus, which is a frequent cause of nosocomial infections in paediatric patients, has prompted this research to empower the usage of various combinations of penicillin. During the study period 17,452 clinical samples were processed for culture. The positive cultures yielded 564 strains of S. aureus. Out of these, 362 (64.2%) isolates were found to be methicillin sensitive S. aureus (MSSA) and 202 (35.8%) methicillin resistant S. aureus (MRSA). The frequency of S. aureus isolates from male patients (355; 63.1%) was found to be higher than female patients (209; 36.9%) and those from indoor wards (441; 78.2%) were more than the outdoor wards (123; 21.8%). Frequency distribution of S. aureus showed to be highest among blood 342 (60.6%) and cerebrospinal fluid 100 (17.8%) samples. The sensitivity pattern of MSSA with piperacillin-tazobactam was 344 (95.0%), ampicillin-sulbactam 340 (93.9%), co-amoxiclav 332 (91.8%) and ampicillin-oxacillin 257 (71.0%). MRSA susceptibility to piperacillin-tazobactam was 143 (71.0%), ampicillin-sulbactam 114 (56.6%), co-amoxiclav 61 (30.2%) and ampicillin-cloxacillin 18 (9%). The Cochran Mantel Haenszel test showed that the effectiveness for each penicillin was associated significantly (p<0.05) with both the MSSA and MRSA. The combinations of piperacillin-tazobactam, ampicillin-sulbactam, co-amoxiclav and ampicillin-cloxacillin exhibited higher efficacy than using them alone to combat Staphylococcal infections.