Introduction. Early detection of carbapenem-resistant Escherichia coli (CREco), categorized as a critical priority pathogen by the World Health Organization (WHO), is crucial in optimizing therapeutic options and to thwart outbreaks in clinical settings. Gap statement. The need of the hour is a diagnostic method that can detect carbapenem resistance conferred by intrinsic or acquired carbapenem resistance mechanisms or both. Aim. The study investigates the performance of a novel screening chromogenic method for detection of CREco. Methodology. Carbapenem-susceptible (n=23) and non-susceptible (n=90) E. coli were used to investigate the efficiency of the blue chromogenic test. All of the isolates were received from a tertiary referral hospital in Silchar, India and subjected to the blue chromogenic test and observed for colour change. A colour change from colourless to blue is interpreted as a positive result. The test results were further compared with available methods for detection of carbapenem resistance conferred by carbapenemase production or other carbapenem resistance mechanisms. Results. The blue chromogenic test generated 100 % (CI: 95.98–100 %) sensitive and 100 % (CI: 85.75–100 %) specific results for the detection of CREco with no false-positive or false-negative results. Within 3 h after incubation, the test detects all CREco with carbapenemase activity. Additionally, the blue chromogenic test also positively detected E. coli harbouring carbapenemase variants and with efflux and porin activity, compared to other phenotypic-based approaches. Conclusion. The study highlights a novel method that is highly sensitive and specific, inexpensive, rapid and user-friendly for the detection of CREco. With the surge and expansion of CREco, this sensitive, specific, user-friendly and inexpensive method can be used in laboratories with limited facilities for early detection of CREco, thereby improving infection control along with averting future outbreaks.

中文翻译：

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一种新型显色筛选方法检测耐碳青霉烯类大肠杆菌的评价

简介。早期检测碳青霉烯类耐药性大肠杆菌 (CREco)，归类为关键菌株世界卫生组织（WHO）将其列为优先病原体，对于优化治疗选择和阻止临床环境中的疫情爆发至关重要。 差距陈述。当前需要的是一种诊断方法，可以检测由内在或获得性碳青霉烯类耐药机制或两者兼而有之的碳青霉烯类耐药性。 目的。该研究调查了一种用于检测 CREco 的新型筛选显色方法的性能。 方法。碳青霉烯类敏感（n=23）和不敏感(n=90)大肠杆菌用于研究效率蓝色显色试验。所有分离株均来自印度锡尔查尔的一家三级转诊医院，并进行蓝色显色测试并观察颜色变化。颜色从无色变为蓝色被解释为阳性结果。将测试结果进一步与检测碳青霉烯酶产生或其他碳青霉烯类耐药机制所赋予的碳青霉烯类耐药性的现有方法进行比较。 结果。蓝色显色测试产生 100 %（CI：95.98–100 %）敏感度和 100 %（CI：85.75–100 %）特异性结果CREco 检测无假阳性或假阴性结果。孵育后 3 小时内，该测试检测到所有具有碳青霉烯酶活性的 CREco。此外，与其他基于表型的方法相比，蓝色显色测试还阳性检测到含有碳青霉烯酶变体并具有外排和孔蛋白活性的大肠杆菌。 结论。该研究强调了一种高度灵敏、特异、廉价、快速且用户友好的 CREco 检测新方法。随着CREco的激增和扩展，这种灵敏、特异、用户友好且廉价的方法可以在设施有限的实验室中使用，以早期检测CREco，从而改善感染控制并避免未来的疫情爆发。