A study on the antimicrobial resistant patterns of Pseudomonas Aeruginosa isolated from raw milk samples in and around Tirupati, Andhra Pradesh.

This study was aimed to detect the prevalence of Pseudomonas aeruginosa in milk (n= 125) samples which were collected from local vendors, private dairy farms in and around Tirupati. Pre-enrichment was done by taking 10ml of each sample and inoculated in 90 ml of Tryptone Soya broth and incubated at 37°C for 24hrs. A loopful of culture was taken from broth and streaked on nutrient agar and Cetrimide agar plates and incubated at 37°C for 24hrs which were further confirmed by biochemical tests. The nineteen positive samples for P.aeruginosa were further tested for antimicrobial susceptibility which has shown multi drug resistant ranging from four to twelve antimicrobials and Multiple Antibiotic Resistance (MAR) index ranges from 0.33 to 1. The isolates of P. aeruginosa in the present study are highlyresistant to ampicillin, penicillin, and oxacillin (100%) and maximum sensitive to Vancomycin (5.3%) followed by Tetracycline (10.5%).