Isolation and Identification of Specific Pathogens, Presence of Antibiotics, Aflatoxins, Pesticide Residues and Industrial Contaminants in Supply Chain of Milk in Selected Coastal Districts of Andhra Pradesh

Abstract

A research study was undertaken to carry out isolation and identification of specific pathogens, presence of antibiotics, aflatoxins, pesticide residues and industrial contaminants in supply chain of milk in selected coastal districts of Andhra Pradesh. The milk is a whole food; it is categorized under perishable foods as it is biologically nutrient liquid that supports the growth of wide variety of microorganisms and is susceptible to spoilage. The quality of milk can be affected by the presence of additional water, detergents, disinfectants, antibiotics, pesticides and pathogens like bacteria, viruses, toxins released by molds such as aflatoxins and heavy metals etc. The raw milk is usually colonized by pathogens like Campylobacter jejuni, enterohemorrhagic Escherichia. coli, Salmonella typhimurium, Listeria monocytogenes, Staphylococcus aureus and Yersinia enterocolitica. The milk samples were collected from vendors of East and West Godavari, Visakhapatnam, Vizianagaram and Srikakulam districts. The milk samples were found to be positive for Tetracycline and Beta lactam antibiotics. The Aspergillus flavus was identified and the colonies producing aflatoxin M1 appeared in yellow color on the Aspergillus agar (M1127). The pesticides and heavy metals in raw and chilled milk samples were detected by atomic absorption spectrophotometer. The pesticide residues were found in raw and chilled milk samples include Lindane, Endosulfan, Chlorane, Heptachlor and Methoxchlor. The heavy metals like lead, arsenic, zinc and mercury residues were found to occur in raw and chilled milk samples. The hygienic quality of the milk in the current study was found to be poor due to exceeding the standard limits in number of specific pathogens, antibiotic, aflatoxin M1, pesticide and heavy metal residues. Immediate measures are needed to be taken to ensure safety of raw milk in public point of view in Visakhapatnam, East & West Godavari regions.