Antimicrobial profiling and molecular characterization of antibiotic resistant genes of Proteus vulgaris isolated from tertiary care hospital, Islamabad, Pakistan

Abstract

Urinary tract infections (UTIs) are among the most common bacterial infections acquired from hospitals and community. Pseudomonas and Proteus species are the common cause of these UTIs. Generally, UTIs are self-limiting but have potential to re-occur. Extensive treatment therapy with antibiotics lead to the development of resistance in uropathogens. The development of antibiotic resistance is leading to the failure of currently available antibiotic based therapies thus making the situation worse. The objective of the present study was to access antimicrobial sensitivity and to characterize antibiotic resistant genes of Proteus vulgaris (P. vulgaris) isolated from patients suffering with UTIs. A total of 150 urine samples were collected and cultured on MacConkey agar medium followed by isolation and identification on blood agar medium. Biochemical characterization of all presumptive Proteus isolates was done using Remel Rap ID one kit. Antibiotic sensitivity for P. vulgaris isolates was performed by disc diffusion method. Presence of blaTEM and qnr antibiotic resistant genes was determined by PCR. The results showed that the overall prevalence of P. vulgaris in clinical samples was 11.3%. It showed maximum resistance (94%) to three antibiotics i.e. ampicillin, tigecycline and chloramphenicol, while least resistance was observed against imipenem (12%). Statistical analysis depicted that imipenem had a significantly larger zone of inhibition (P=.01), while ampicillin had significantly smaller zone of inhibition (P=.0004) followed by chloramphenicol (p-value = 0.002). Imipenem should be considered as an effective antibiotic to treat urinary tract infections associated with P. vulgaris. Both blaTEM and qnr genes were found to be involved in conferring resistance to β-lactam and quinolones antibiotics.