Microbiological Quality and Detection of Antibiotic Residue in Raw and Pasteurized Milk Consumed in the Reconcavo Area of the State of Bahia,Brazil

Abstract

The aim of this work was to check the presence of total and thermo tolerant coliforms, mesophilous microorganisms, Escherichia coli, as also residue of antimicrobian agents in raw and pasteurized milk. For this purpose, an analysis was conducted on 50 samples of raw milk and 20 of pasteurized milk from 10 municipalities of the Reconcavo da Bahia, Brazil, through the establishment of the number of total coliforms, thermo tolerant and Escherichia coli using the multiple tube technique, and also the establishment of mesophile microorganisms by deep spreading. For the detection of antimicrobian residue, the DelvotestReg. kit was used. The counts of total coliforms found in raw milk varied between 2.42x10 9 and 9.02x10 10 NMP/mL. The mean values varied between 9.43x10 8 and 9.02x10 10 NMP/mL to thermo tolerant coliforms. With regard to Escherichia coli means varied between 1.52x10 6 and 2.20x10 10 NMP/mL, and for mesophilous microorganisms the means ranged from 7.85x10 9 and 4,75x10 9 CFU/mL. In pasteurized milk the counts of total coliforms found 4,16x10 3 and 3,66x10 11 NMP/mL. The mean varied between 4,16x10 3 and 3,10x10 9 NMP/mL to thermo tolerant coliforms. With regard to Escherichia coli means varied between <3 and 2,54x10 8 NMP/mL, and for mesophilous microorganisms the means ranged from 4,59x10 3 and 3,60x10 9 CFU/mL. None of the samples presented any evidence of residue of antibiotics.