PARTIAL CHARACTERIZATION OF MULTI DRUG RESISTANT BACTERIAL ISOLATES RECOVERED FROM URINARY TRACT INFECTIONS OF HUMAN PATIENTS

Abstract

ABSTRACT newlineExtended spectrum and#946;- lactamases (ESBLs) and Metallo and#946;- lactamases expressing Gram negative bacilli are now the common cause of community acquired infections and urinary tract infections (UTIs) are one of them. It represents a challenge for practitioners in choosing empirical antibiotics. The formation of the biofilms by these micro-organisms further lead to treatment failure. The present study aimed at the screening of E. coli (n=15), P. aeruginosa (n=15) and S. aureus (n=34) isolates recovered from the UTIs of the human patients for the production of ESBLs, MBLs and the biofilms. The isolates of E. coli were sent for serotyping at Central Research institute (CRI), kasauli, H.P. The serotype O141 was predominant and othe serotypes found were O147 and O76. 100% of E. coli isolates were resistant to aztreonam, cefuroxime, ceftazidime and ceftriaxone whereas 100% of P. aeruginosa were resistant to cefuroxime and cefpodoxime in the screening test which was done by disc diffusion method and 66.6%, 60%, 25% isolates of P. aeruginosa, E. coli and S. aureus respectively were confirmed as ESBL producers by DDST. Then, isolates were screened for MBL production by disc diffusion method and confirmed by combined disc test. MBL production rate was found to be 55.55% and 53.84% in the isolates of P. aeruginosa and E. coli. None of the isolate of S. aureus was MBL producer. The isolates were screened for biofilm production by three different methods including congo red agar method, tube method and tissue culture method. 93.3%, 93.5%, 86.6% isolates of E. coli, 86.6%, 73.6%, 73.32% isolates of P. aeruginosa, 96.99%, 96.99%, 94.11% isolates of S. aureus were biofilm producers by congo red agar, tube and tissue culture plate methods respectively. The isolates were investigated for their susceptibility to extracts of C. sinensis (tea) and M. koengii (curry) which were prepared in different solvents (aqueous, ethanolic and methanolic) and further MIC ranges were determined as well as MIC50 was calculated. The ethanolic extract of C. sinensis showed the best inhibitory activity against the isolates and MIC range was recorded as 62.5 -250 mg/ml for E. coli and S. aureus whereas it ranged between 62.5 -500 mg/ml for P. aeruginosa isolates. The MIC50 for ethanolic extract of C. sinensis was calculated as 119.8mg/ml, 237.5 mg/ml and 273.43 mg/ml respectively for E. coli, S. aureus and P. aeruginosa respectively. The aqueous extract of M. koengii did not show any inhibitory activity against any of the isolates tested. The extracts were also tested for their inhibitory activity against the biofilms. The ethanolic extract of tea only showed a moderate biofilm inhibiting activity against the biofilms of S. aureus. newline