Search

Background: Quantitative urine culture reporting on plates inoculated by automated streaking system (PREVI® Isola) demonstrates maximum growth only equivalent up to 104 colony-forming unit (CFU)\ml, according to the manufacturer's recommendation. Therefore, there is a probability of erroneous catheter-associated urinary tract infection (CAUTI) surveillance data as a count of ≥105 CFU/ml is required according to CAUTI definition. This study aimed to validate automated urine culture streak system for improving the surveillance of hospital-acquired CAUTIs. Materials and Methods: This was a prospective, cross-sectional study. In 1-month duration, urine samples of 1000 consecutive patients reported to the microbiology section for culture and sensitivity were included. Samples were processed simultaneously manually (1 μl loop) and with an automated streaking system. Plates streaked by automated method were arbitrarily divided into eight equally sized segments. After 24 h of incubation at similar conditions, microbial growths in each segment were noted and correlated with its manual colony count. To minimize the error, colony count and morphotype were analyzed by a senior technologist and counterchecked by a consultant. Results were recorded on an Excel sheet. Results: Growth on the 7th and 8th segments corresponded with ≥105 CFU/ml. Growth up to the 4th, 5th, and 6th segments corresponded with 104 CFU/ml, whereas the 3rd segment with >103 but

Background: This study aimed to compare the accuracy of Candida species identification by direct inoculation of positive blood culture specimens into CornMeal Tween™ (CMT) 80 agar with the conventional methods. Methods: This study was performed in two phases: Phase 1: Inoculation of direct CMT from artificially spiked blood culture bottles with identified Candida species. Phase 2: Direct inoculation of smear-positive bottles on CMT agar for identification. Routine identification method was carried out using urease production, sensitivity to cycloheximide, CMT inoculation, and colony morphology on BiGGY agar. All isolates were also evaluated for sugar assimilation on the biochemical test panel Analytical profile index (API) 20C AUX (BioMerieux). Statistical Analysis Used: The correlation between both methods was determined as percentage agreement rate using kappa score. Results: In the first phase 50 artificially spiked blood culture bottles were included in the study. The sample set consisted of 24% C albicans, 38% C tropicalis, and 22% C glabrata isolates. There was 100% agreement between the directly inoculated and CMT inoculated from colonies at 48 hours. Phase 2: The overall agreement between directly inoculated CMT and conventional method of identification at 72 h was 92%. Conclusion: Direct inoculation of CMT agar can easily differentiate common Candida species microscopically on the basis of chlamydospores, blastopores, and arrangement of pseudo hyphae. However, identification of rare species from specimens containing two different species using direct method is challenging. Therefore, conventional methods including macroscopic/microscopic characteristics and biochemical profile with the aid of API with API 20 AUX would be a better choice for such cases.