Evaluation of an automated rapid urine culture method for urinary tract infection: Comparison with gold standard conventional culture method

Bhawna Sharma; Balvinder Mohan; Rashmi Sharma; Vikas Lakhanpal; Pinky Shankar; Shrawan Kumar Singh; Neelam Taneja

doi:10.1016/j.ijmmb.2023.01.003

Evaluation of an automated rapid urine culture method for urinary tract infection: Comparison with gold standard conventional culture method

Indian J Med Microbiol. 2023 Mar-Apr:42:19-24. doi: 10.1016/j.ijmmb.2023.01.003. Epub 2023 Jan 20.

Authors

Bhawna Sharma¹, Balvinder Mohan², Rashmi Sharma², Vikas Lakhanpal³, Pinky Shankar², Shrawan Kumar Singh⁴, Neelam Taneja⁵

Affiliations

¹ Department of Microbiology, AIIMS, Bathinda, India.
² Department of Medical Microbiology, PGIMER, Chandigarh, India.
³ Department of Neurology, AIIMS, Bathinda, India.
⁴ Department of Urology, PGIMER, Chandigarh, India.
⁵ Department of Medical Microbiology, PGIMER, Chandigarh, India. Electronic address: drneelampgi@yahoo.com.

PMID: 36967210
DOI: 10.1016/j.ijmmb.2023.01.003

Abstract

Purpose: Urinary tract infection is one of the most prevalent disease affecting people from all age groups. For its diagnosis, conventional culture and antibiotic susceptibility is the gold standard. However, its major limitation is that the results take minimum of 24 h and antibiotic susceptibility is available after 48 h. Automated culture methods having comparable sensitivity and specificity as compared to conventional culture should be evaluated for routine diagnostics. With this aim we evaluated the diagnostic accuracy of automated urine culture method HB&L uroquattro by comparing with the gold standard conventional culture method.

Materials and methods: A total of 1220 urine samples were included in the study. Semi-quantitative urine culture was performed using standard methods on cysteine lactose electrolyte deficient medium. For the automated culture, HB&L Uroquattro (Alifax, Polverara, PD, Italy), standard guidelines given in the manual of the instrument were followed. Diagnostic performance in terms of sensitivity, specificity, positive and negative likelihood ratios, positive and negative predictive values were calculated.

Results: Based on the final interpretation of conventional culture for the total 1220 samples, 26 samples (2.1%) showed major non-concordance as they were identified as sterile by HB&L but had significant growth by conventional culture and 19.9% showed minor non-concordance. At 100-999 colony forming unit/ml, HB&L has high negative predictive value i.e. 96.6% with 95% CI (95.2%-97.6%) and sensitivity i.e. 92.66% with 95% CI of (89.42%-95.15%).

Conclusion: The HB&L Uroquattro seems to be a reliable instrument to obtain urine microbiological results in a timely manner. This technique can give presumptive report to the clinician within 5 h only for initiation of empirical antibiotics in cases of positive results.

Keywords: Automated culture; Diagnostic accuracy; Urinary tract infection.

MeSH terms

Anti-Bacterial Agents
Humans
Predictive Value of Tests
Sensitivity and Specificity
Urinalysis / methods
Urinary Tract Infections* / diagnosis
Urinary Tract Infections* / microbiology

Substances

Anti-Bacterial Agents