Multidrug Resistant Bacterial Isolates at Nobel Medical College Teaching Hospital

Abstract

Antimicrobial resistance is one of the big issues especially among members of family enterobacteriaceae. This study was conducted for a period of 6 months from January to June 2011 at Nobel Medical College Teaching Hospital and Research Centre with the objective to know the multi-drug resistant bacterial isolates of family enterobacteriaceae from different clinical samples. A total of 2454 non-repeated clinical samples were processed during the study by using standard microbiological techniques and the antibiotic susceptibility pattern in vitro was evaluated by modified Kirby-Bauer disc diffusion method. The total growth was 25.35% (n=622). Among them gram positive and gram negative bacteria accounted for 48.0% (n=298) and 52.0% (n=324) respectively. Of total gram negative isolates, 92.60% (n=300) belonged to family enterobacteriaceae and 7.40% (n=24) were gram negative other than enterobacteriaceae (Pseudomonas aeruginosa; Acinetobacter species). The bacterial isolates were of 6 different species isolated from 7 different clinical specimens. Among them, E. coli 237/300 (79.0%) were the most predominant followed by Citrobacter species 36/300 (12.0%), Klebsiella pneumoniae 16/300 (5.33%) and Enterobacter species, Proteus mirabilis and Morganella morganii with 0.33% each. Among the antibiotics used, imipenem (98.11%) followed by amikacin (89.55%), meropenem (89.47%) and choramphenicol (78.37%) were found to be most effective. About half of the isolates were susceptible to cefotaxime (52.90%), ceftazidime (42.34%) and ciprofloxacin (53.50%). Overall 59.00% (n=178) of the isolates were multiple-drug resistant with higher among in-patients than out-patients (p<0.05). Of total multiple-drug resistant, E. coli accounted for highest 81.35% (n=144) followed by Citrobacter species 14.40% (n=25). Of total E. coli isolated 52.74% (144/273) were multiple-drug resistant while 69.44% (25/36) and 40.00% (6/15) Citrobacter species and K. pneumoniae respectively were multiple-drug resistant. The study found the higher magnitude of the problems of multiple-drug resistance among enterobacteriaceae that necessitates a reevaluation of first and second line therapies for the treatment of infections due to these organisms and regular monitoring of the usage in order to make reliable information available for optimal empirical therapy.