Microbiological quality and safety of goat’s milk from one farm

Abstract

In recent years, the popularity of goat’s milk and goat’s milk products has been growing in the Czech Republic, especially for its low allergenic potential and good digestibility. This study focused on the assessment of the microbiological quality and safety of raw and heat-treated goat’s milk. During the lactation period, total of 48 samples of raw and 40 samples of pasteurized goat’s milk were collected on a goat’s farm in the South Moravian Region of the Czech Republic. Quantitative analysis was performed to determine the total plate count (TPC) and coagulase-positive (CP) staphylococci count. The presence of E. coli including E. coli O157, CP staphylococci, B. cereus, L. monocytogenes, Salmonella spp., and Campylobacter spp. was detected. The monthly average TPC ranged from 4.53 to 5.21 log CFU.ml−1 in raw milk and from 2.36 to 3.71 log CFU.ml−1 in pasteurized milk. Thirty (75.0%) S. aureus isolates from raw milk carried the sec gene, two (5.0%) were positive for the genes seb, seg, sei, and one (2.5%) harboured the seg and sei genes. Pasteurized goat’s milk samples yielded a single isolate of S. aureus carriyng the sec gene. One isolate of E. coli serotype O156 producing ST1 toxin was recovered from raw milk. B. cereus was detected only in two pasteurized goat’s milk samples. Any other pathogens monitored were not detected. In this study, shigatoxin-producing E. coli O156 was detected in raw goat’s milk for the first time in the Czech Republic.

Keywords

• raw milk
• pasteurized milk
• total plate count
• staphylococal enterotoxins
• STEC
• indicator bacteria