Evaluation of virulence genes in Proteus strains isolated from diabetic foot infections and urinary tract infections

Abstract

Introduction: Proteus species are frequently isolated from urinary tract infections (UTIs) and diabetic foot infections (DFIs). We aimed to evaluate the presence of virulence genes in P. mirabilis and P. vulgaris strains isolated from DFI and UTI.

Methodology: A total of 78 Proteus isolates (57 P. mirabilis and 21 P. vulgaris) collected from patients were studied. The isolates were identified using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometer. The presence of virulence-associated genes (hlyA, mrpA, atfA, pmfA, hmpA, ptaA, ureA, ureC, zapA, ireA, rsbA, flaA, and ucaA) was evaluated by polymerase chain reaction (PCR).

Results: 46 isolates were obtained from wound cultures, and 32 were obtained from the midstream urine cultures. All virulence genes, except hlyA, were detected in the study. ureA was the most detected gene in both UTI (100%) and DFI isolates (84.8%). The distributions of ureC, flaA, hpmA, ireA, rsbA, pmfA, zapA, ucaA, ptaA, atfA, and mrpA genes in DFI and UTI isolates were as follows: 82.6% and 96.9%, 71.7% and 93.8%, 69.6% and 93.8%, 69.6% and 96.9%, 69.6% and 96.9, 67.4% and 81.3%, 65.2% and 43.8%, 54.3 and 71.9%, 34.8% and 96.9%, 26.1 and 93.8%, and 23.9% and 46.9%, respectively.

Conclusions: We demonstrated that P. mirabilis and P. vulgaris express a variety of virulence genes related to pathogenicity. All virulence genes were found to be more frequent in UTI isolates except zapA. There is limited data on the virulence factors of Proteus species in DFIs. Further studies are needed to investigate virulence genes in wound isolates.