Detection of Bacteria Contaminating Milk and Milk Products in Tanzania by Conventional and Rapid Methods

Le résumé fourni par la source

The aim of the present study was to evaluate the performance of rapid methods for identifying contaminating bacteria in milk and milk products in Tanzania. A total of 60 milk and milk product samples were collected along the dairy value chain in Morogoro Municipality. The samples included raw and boiled milk, local fermented milk, and industrial processed milk products. Laboratory analyses were conducted using the conventional tests (culture and confirmatory tests) as well as rapid methods (3M petrifilm plate and polymerase chain reaction (PCR). Total bacteria count and identification of Escherichia coli as well as Staphylococcus aureus were performed. Results had indicated that there is positive correlation (R=1) between the 3M petrifilm and conventional methods. On the other hand, the correlation between PCR and the conventional method was poor (R=-0.078 and -0.15 for E. coli and S. aureus identification respectively). Furthermore, the PCR identified more positive samples (8 for E. coli and 12 for S. aureus) compared to the conventional method (2 for E. coli and 5 for S. aureus). No significant difference (p˂0.05) was observed between 3M petrifilm and the conventional methods in tested boiled milk, local fermented milk, and industrial processed milk products; however, significant differences (p˃0.05) were observed in raw milk by both methods. Based on these results and the time to obtain them, it is confirmed that rapid methods performed better than the conventional methods for determining contamination and identifying bacteria in milk and milk products and are hence recommended for routine laboratory analysis in Tanzania.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.