Validation and impact of the use of automated urine culture streak system in a diagnostic laboratory on surveillance of catheter-associated urinary tract infections at a tertiary care setting

Authors

Mohammad Zeeshan, Aga Khan University
Joveria Farooqi, Aga Khan UniversityFollow
Saeeda Chandio, Aga Khan UniversityFollow
Zohra Rafiq, Aga Khan UniversityFollow
Rozina RoshanFollow
Seema Irfan, Aga Khan UniversityFollow

Document Type

Article

Department

Pathology and Microbiology; Pathology and Laboratory Medicine

Abstract

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 7^th and 8^th segments corresponded with ≥10⁵ CFU/ml. Growth up to the 4^th, 5^th, and 6^th segments corresponded with 10⁴ CFU/ml, whereas the 3^rd segment with >10³ but <10⁴ CFU/ml. Any growth in the 1^st and 2^nd sectors was considered insignificant.
Conclusion: Quantitative urine culture analysis inoculated by automated streak system corresponds to the CAUTI surveillance definition. Colony count requires validation with manual method before implementing in laboratory.

Publication (Name of Journal)

Biomedical and Biotechnology Research Journal

Recommended Citation

Zeeshan, M., Farooqi, J., Chandio, S., Rafiq, Z., Roshan, R., Irfan, S. (2019). Validation and impact of the use of automated urine culture streak system in a diagnostic laboratory on surveillance of catheter-associated urinary tract infections at a tertiary care setting. Biomedical and Biotechnology Research Journal, 3(3), 202-205.
Available at: https://ecommons.aku.edu/pakistan_fhs_mc_pathol_microbiol/1220