Isolation of psychrotrophic multiple drug resistant Pseudomonas from pasteurised milk

Abstract

The present study was taken up with the objective of assessing the microbiological quality of milk processed in an organized dairy plant. The standard plate count and coliform count of all the samples tested were within the limits specified by Prevention of Food Adulteration standards. However microbiological analysis of pasteurized milk revealed a unique bacterial profile characterized by the predominance of Pseudomonas aeruginosa. Assessment of potential of the isolate to multiply at 7°C confirmed its psychrotrophic nature. Antibiogram of the isolate revealed that, of the seven antibiotics tested, the isolate was sensitive only to enrofloxacin. Results are suggestive of the trait of multiple drug resistance in the isolate. Such multiple drug resistant (MDR) bacteria in processed foods are potent biological hazards as there are possibilities for resistance genes to be spread to human beings via food. Isolation of such Multiple drug resistant (MDR) bacteria in pasteurised milk, an essential component of human diet is highly significant from the public health point of view. Presence of Pseudomonas species in processed products implies that post processing contamination can hinder even the quality of properly processed products. The result signifies the importance of appropriate handling practices of processed food to assure safe products at consumer level.