Sharma Bhawna, Mohan Balvinder, Sharma Rashmi, Lakhanpal Vikas, Shankar Pinky, Singh Shrawan Kumar, Taneja Neelam
Department of Microbiology, AIIMS, Bathinda, India.
Department of Medical Microbiology, PGIMER, Chandigarh, India.
Indian J Med Microbiol. 2023 Mar-Apr;42:19-24. doi: 10.1016/j.ijmmb.2023.01.003. Epub 2023 Jan 20.
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.
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.
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%).
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.
尿路感染是影响所有年龄组人群的最常见疾病之一。对于其诊断，传统培养和抗生素敏感性检测是金标准。然而，其主要局限性在于结果至少需要24小时，抗生素敏感性检测结果在48小时后才能获得。应评估与传统培养具有可比敏感性和特异性的自动化培养方法用于常规诊断。基于此目的，我们通过与金标准传统培养方法比较，评估了自动化尿液培养方法HB&L uroquattro的诊断准确性。
本研究共纳入1220份尿液样本。使用标准方法在半胱氨酸乳糖电解质缺乏培养基上进行半定量尿液培养。对于自动化培养，遵循意大利阿尔ifax公司生产的HB&L Uroquattro仪器手册中给出的标准指南。计算了敏感性、特异性、阳性和阴性似然比、阳性和阴性预测值等诊断性能指标。
根据对全部1220份样本的传统培养最终解读，26份样本（2.1%）显示出主要不一致性，因为它们被HB&L鉴定为无菌，但传统培养有显著生长，19.9%显示出轻微不一致性。在每毫升100 - 999个菌落形成单位时，HB&L具有较高的阴性预测值，即96.6%，95%置信区间为（95.2% - 97.6%），敏感性为92.66%，95%置信区间为（89.42% - 95.15%）。
HB&L Uroquattro似乎是一种能够及时获得尿液微生物学结果的可靠仪器。对于阳性结果的病例，该技术仅需5小时就能为临床医生提供初步报告以便开始经验性使用抗生素。
