Isolation and Molecular Identification and Antimicrobial Susceptibility of Providencia spp. from Raw Cow’s Milk in Baghdad, Iraq

Abstract

A total of sixty raw milk samples were collected from (street vendors and shops) from Baghdad city, Iraq. The samples were inoculated into peptone water and, then, subcultured onto MacConkey agar and Blood agar. Identification of isolates was confirmed by microscopic examination, cultural characteristic, biochemical tests, Vitek (VITEK®2 system), and Biolog GN substrate reactions followed by 16S rRNA and specific genes sequencing. Of 60 raw cow’s milk samples, Providencia spp. were identified only in 4 samples (6.67%) and P. rettgeri was the most common, 2/4 (50%), followed by P. stuartii and P. vermicola, 1/4 (25%). Antimicrobial susceptibility tests were conducted against ten antibiotics by the disc diffusion method. All Providencia isolates showed multidrug resistance (MDR), and the absolute resistant was 100% to tetracycline, erythromycin, and doxycycline and 50% against ampicillin\sulbactam and amoxicillin/clavulanic acid. They were highly susceptible (100%) to trimethoprim, imipenem, and chloramphenicol. These findings indicate that milk might be contaminated with Providencia spp. leading to transmission to humans causing poisoning, diarrhea, and other infections. This is the first study of isolated Providencia spp. from raw cow’s milk.