Multi-drug resistant uropathogenic Escherichia coli and its treatment by Chinese medicine.

Objectives: To investigate the resistance and virulence profiles of uropathogenic Escherichia coli (UPEC) and its treatment by Chinese medicine (CM) Fuzheng Qingre Lishi Formula (, FQLF).
Methods: UPEC strains were isolated from recurrent urinary tract infections (UTIs) patients. Patient sensitivities to 17 antibiotics were tested by the disk diffusion method. Virulence genes were screened by plolymerase chain reaction. A mouse model was constructed using a multi-drug resistant and virulent UPEC strain and treated with FQLF or the antibiotic imipenem. The treatment efficacy was evaluated by bacterial clearance from urine and the urinary organs.
Results: A total of 90 UPEC strains were collected, and 94.4% of the isolates were resistant to at least 1 antibiotic. Approximately 66.7% of the UPEC strains were multi-drug resistant. More than one virulence gene was found in 85.6% of the isolates. The extended-spectrum β-lactamases (ESBL)-positive strains were more resistant than the negative ones. The virulence gene number was positively correlated with the resistance number (P<0.05). A mouse model was successfully constructed using UPEC10. Treatment with either FQLF or antibiotics significantly cleared bacteria from the mouse urine after 14 days. In the untreated control, the bacteria lasted for 28 days. FQLF treatment of the UTI mouse model greatly reduced the bacterial number in the kidney and bladder, but could not completely clear the bacteria.
Conclusions: Multi-drug resistance is common among UPEC isolates, and the resistance is positively related with virulence. FQLF could treat UPEC UTIs, but could not completely clear the bacteria from the host.