Antibiotic resistance is a pressing public health issue with significant clinical and economic repercussions worldwide. Addressing this challenge requires strategies at different levels, including increasing surveillance, accelerating diagnosis, and finding new treatments. The BL-DetecTool project, funded by the European Institute of Innovation and Technology (EIT-Health) and involving the participation of the Barcelona Institute for Global Health (ISGlobal), was launched four years ago with the aim of validating a rapid test for detecting two types of molecules that confer resistance to antibiotics: extended-spectrum beta-lactamases (enzymes capable of breaking down cephalosporins) and carbapenemases (capable of breaking down last-line carbapenem antibiotics).

The BL-DetecTool is a rapid and simple test based on a lateral flow immunoassay (similar to pregnancy or COVID-19 tests) to detect a series of extended-spectrum beta-lactamases (ESBLs) and/or five of the main carbapenemases produced by multidrug-resistant bacteria (including Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa). The test provides results in 35 minutes directly from positive blood cultures or urine samples, as well as rectal swabs.

Nine European centers participated in the study – in Spain (including the Hospital Clinic), France, Hungary, Greece, Italy, and Germany – to evaluate the test on a total of 22,010 biological samples.

High sensitivity directly from urine and blood The prevalence of extended-spectrum beta-lactamase-producing bacteria ranged from 6% to 29%, depending on the hospital, and the test demonstrated high sensitivity for detecting them from positive blood cultures (over 90%) and urine samples (over 94%, except for one hospital where eight samples gave false positives). For rectal samples, specificity was more variable but increased above 75% with prior sample treatment.

As expected, the prevalence of carbapenemase-producing bacteria was lower: between 1.9% and 20% in five hospitals, while none were detected in the other four. Excluding the hospital with the lowest prevalence, the sensitivity of the test was 75% to 100% for blood or urine samples. Once again, rectal samples required prior treatment to increase sensitivity above 66%.

«The observed sensitivity is slightly lower than previously reported for the BL-DetecTool, but this is due to the high number of samples in our cohort and the multicenter design of the study,» says Mariana Fernandez-Pittol, a researcher at the Hospital Clinic and the study’s lead author.

The results confirm that the BL-DetecTool enables rapid and reliable detection of extended-spectrum beta-lactamases and carbapenemases directly from positive blood cultures or urine, as well as enriched rectal samples. «This technique is easy to implement and will greatly facilitate work in clinical microbiology laboratories,» adds Vila.

Article written by Salud a Diario| Image by Unspash



Salud a Diario