ABSTRACT
Objective: Urine is the most frequent specimen received for culture/sensitivity by clinical laboratories
The microbiological performance of HiCrome UTI agar medium was compared with Blood agar and MacConkey agar for isolation and presumptive identification of bacteria from urine culture
Methods: A total of 443 consecutively collected midstream and/or catheter-catch urine samples from patients attending the Islami Bank Medical College Hospital, Rajshahi, Bangladesh during January to December, 2012 were cultured. Urine samples showing pus cells > 5/HPF were inoculated on to Blood agar [BA], MacConkey agar [MAC] and HiCrome UTI agar [CA] media simultaneously and incubated overnight aerobically at 37°C. Rate of isolation and presumptive identification of bacterial species were compared for different media
Results: Culture yielded a total of 199 bacterial isolates from 189 [42.67%] positive plates including 179 [40.40%] unimicrobial and 10 [2.26%] polymicrobial [mixed growth of pair of bacteria] growths. Both HiCrome UTI agar and Blood agar media supported 100% growths while 151 [75.88%] growths were observed on MacConkey agar
The rate of presumptive identification was found significantly higher on HiCrome UTI agar [97.49%] than MAC agar [67.34%] [P<0.001] as primary urine culture medium. Of 199 isolates, E. col7 was found to be the leading uropathogen isolated from 118 [59.30%] samples with its presumptive identification rate of 95.76%, 93.22% and 5.93% on CA, MAC and BA respectively. All 10 [100%] polymicrobial growths were demonstrated distinctly on CA against only 01 [10%] on each BA and MAC
Conclusion
HiCrome UTI agar was found to be more useful as primary urine culture medium in both higher rate of isolation and presumptive identification of uropathogens in comparison to conventional media
Its inherent characteristics in demonstrating polymicrobial growth and ease of rapid identification by distinct colony colour are unique
ABSTRACT
Extended spectrum beta-lactamases [ESBLs] represent a major group of lactamases currently being identified in large number worldwide mostly produced by gram-negative bacteria. The present study was done to see the frequency of ESBLs in gram-negative bacterial isolates causing nosocomial wound infections from a tertiary care hospital in Bangladesh. A total of 125 wound swabs were collected from surgical site infections and burn cases, admitted in Rajshahi Medical College Hospital [RMCH], during January to June, 2008. Swabs were cultured for aerobic bacteria and antimicrobial susceptibility testing was carried out using the Kirby-Bauer agar diffusion method. Gram-negative isolates were tested for ESBLs on Mueller Hinton agar by both modified double disc and phenotypic confirmatory methods. Culture yielded 71 [56.8%] bacterial growths with 60 [84.51%] gram-negative and 11 [15.49%] gram-positive bacteria [Staph aureus]. Gram-negative isolates included 23 [32.39%] E. coli, 19 [26.76%] Klebsiella spp., 16 [22.54%] Pseudomonas spp., and 02 [2.82%] Proteus spp. The number of ESBL producing bacteria in modified double disc and phenotypic confirmatory methods were 28 [46.67%] and 25 [41.66%] respectively. Highest rate of ESBLs was observed in Klebsiella spp. [57.89%] followed by Proteus spp. [50.0%], E. coli [47.83%] and Pseudomonas spp. [31.25%], which showed significantly increasing resistance to 3rd generation cephalosporins, aminoglycoside, quinolone and trimethoprim-sulfamethoxazole. Significant number of nosocomial wound infections is caused by ESBL bacteria; those are not detected by routine antimicrobial susceptibility testing. It is recommended that clinical microbiology laboratory should take urgent measure for ESBLs detection as routine to enhance hospital infection control programme