ISOLATION AND IDENTIFICATION OF ESCHERICHIA COLI O157:H7 FROM FRESH MILK AND FERMENTED MILK (NONO) IN BENIN CITY, EDO STATE, NIGERIA

Authors: *Igbinosa, E.O, Beshiru, A.

DOI Info: N/A

ABSTRACT

This study was designed to investigate the occurrence of Escherichia coli O157:H7 in fresh and fermented milk (nono) in Benin City, Edo State, Nigeria using standard culture-based and polymerase chain reaction methods. A total of 42 milk samples which comprise of fresh milk (n=18) and fermented milk (n=24) were studied between March and May 2017. The heterotrophic cell count from fresh milk ranged between 4.00×10⁹ and 3.39×10¹⁰ cfu/ml while 4.50×10⁹ and 3.65×10¹⁰ cfu/ml were observed for the fermented milk. The E. coli O157:H7 cell count from fresh milk ranged from 3.00×10⁴ to 3.12×10⁶ cfu/ml while a range of 1.00×10⁴ to 3.10×10⁶ cfu/ml were observed for the fermented milk. Other E. coli cell count from fresh milk ranged from 1.00×10⁴ to 1.36×10⁶ cfu/ml while a range of 1.00×10⁴ to 1.08×10⁶ cfu/ml were observed for the fermented milk. Faecal coliforms cell counts from fresh milk ranged from 2.00×10³ to 6.30×10⁴ cfu/ml while a range of 1.00×10³ to 2.76×10⁵ cfu/ml were observed for the fermented milk samples. The population count difference in E. coli O157:H7, other E. coli and faecal coliforms from the fresh and fermented milk samples analysed were statistically significant (p < 0.05). Findings from this study revealed that both the fresh and fermented milk were positive for E. coli O157:H7 as well as other E. coli and faecal coliforms. In addition, the population count from the fresh and fermented milk samples exceeded the permissible limits of European Parliament and of the Council. Therefore, fresh and fermented milk could pose a potential health risk to consumers.

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