Adaptation of Escherichia coli O157:H7 to acid in traditional and commercial goat milk amasi

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Authors

Dlamini, Bhekisisa Chushuta
Buys, E.M. (Elna Maria)

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Publisher

Elsevier

Abstract

Acid resistance of Escherichia coli O157:H7 strains UT 10 and UT 15 were determined in traditional Amasi ermented for 3 days at ambient temperature (ca 30 °C) and commercial Amasi fermented at 30 °C for 24 h and stored at 7 °C for 2 days. Escherichia coli O157:H7 counts in commercial Amasi were detected at 2.7 log10 cfu/ml after 3 days while those in traditional Amasi could not be detected after the same period. There was no significant difference (p≤0.05) in the survival of acid adapted (AA) and non-adapted (NA) E. coli O157:H7 in traditional Amasi, while in commercial Amasi, the NA strain survived significantly (p≤0.05) better than its AA counterpart. Regardless of prior adaptation to acid, E. coli 157:H7 can survive during fermentation and storage of fermented goat milk Amasi. Also, the fermentation time, pH and storage temperature affects the survival of E. coli O157:H7 in the fermented milk.

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Keywords

Acid adaptation, E. coli O157:H7, Goat milk, Amasi, Fermented milk

Sustainable Development Goals

Citation

Dlamini, BC & Buys, EM 2008, 'Adaptation of Escherichia coli 0157:H7 to acid in traditional and commercial goat milk amasi', Food Microbiology, 2008 [doi: 10.1016/j.fm.2008.07.007]