Genome-based development and clinical evaluation of a customized LAMP panel to rapidly detect, quantify, and determine antibiotic sensitivity of Escherichia coli in native urine samples from urological patients.

PURPOSE

We designed and tested a point of care test panel to detect E.coli and antibiotic susceptibility in urine samples from patients at the point of care in the urological department. The aim of this approach is to facilitate choosing an appropriate antibiotic for urinary tract infections (UTI) at first presentation in the context of increasing antibiotic resistance in uropathogens worldwide.

METHODS

We analyzed 162 E.coli isolates from samples from a university urological department to determine phenotypic and genotypic resistance data. With this data we created customized LAMP (loop-mediated isothermal amplification) panels for a commercial machine with which to detect and possibly quantify E.coli and six antibiotic resistance determinants. In a second step we tested these panel(s) for diagnostic accuracy on 1596 urine samples and compared with routine microbiological culture.

RESULTS

E.coli was detected with 95.4% sensitivity and 96.1% specificity. Dynamics of the LAMP amplification could be used to gauge bacterial loads in the samples. Antibiotic sensitivity was detected with good negative (sensitive) predictive values: ampicillin 92.8%, ampicillin/sulbactam 96.4%, cefuroxime 92.8%, cefotaxime 97.8%, trimethoprim/sulfamethoxazole 96.5%, ciprofloxacin 96.8%.

CONCLUSION

The LAMP panel provided E.coli detection and sensitivity information within one hour and thus could principally guide initial antibiotic therapy upon patients presenting with UTI. The panel helps to select initial adequate antibiotic therapy as well as providing diagnostic stewardship. Follow up investigations will expand the test system to other uropathogens.