Some Virulence-Associated Genes of Proteus Isolates Could Predict Antibiotic Susceptibility and Even Infection Source.

BACKGROUND

In the present study, the probable association of virulence-associated genes (VAGs) with antibiotic resistance and also sample sources in Proteus isolates was investigated.

METHODS

Then, 91 Proteus mirabilis and nine Proteus vulgaris were used in this study. The disk diffusion method was used in order to perform an antibiotic susceptibility assessment. A combination double-disc synergy test was used for the evaluation of extended-spectrum β-lactamases. Eight VAGs were investigated by polymerase chain reaction (PCR) method. ERIC-PCR fingerprinting was also performed for P. mirabilis isolates.

RESULTS

Maximum frequency of resistance was detected against trimethoprim-sulfamethoxazole combination in P. mirabilis isolates and against cefalexin in P. vulgaris isolates. Then, 6% of isolates were multidrug-resistant (MDR) and all were P. mirabilis. Community-acquired (CA) isolates were more virulent than hospital-acquired (HA) isolates. The zapA (98%) and atfA (77%) were the most common and less common VAGs, respectively. The study findings showed that mrpA and atfA genes were predictors of sensitivity to some antibiotic agents. The rsbA gene could also be similarly used in order to distinguish CA isolates from HA isolates.

CONCLUSIONS

Higher virulence potential of CA isolates in comparison to the HA isolates is suggested. Amikacin, tobramycin, and meropenem were introduced as the most effective antibiotics against Proteus isolates. Our finding primarily introduced some VAGs as biomarkers for predicting antibiotic susceptibility and also in order to differentiate Proteus isolates. However, it has to be confirmed through complementary studies later.