Fate of Staphylococcus aureus in Experimentally Prepared Fermented Fish Sauce (Mehiawah) PDF

Keywords

Fate, Fermentaion, fish sauce, Mehiawah, Staphylococcus aureus.

Abstract

In a previous study, we have shown that home-made Mehiawah, a fermented fish sauce commonly consumed in the Gulf States and traditionally prepared from dried Sardinella gibbosa (Indian sardines), contained high counts of Staphylococcus aureus, as well as detectable level of staphylococcal enterotoxins. The current study further confirms these findings It also reports the possible fate of inoculated S. aureus in experimentally prepared Mehiawah using four different mehiawah treatments. A coagulase-positive S. aureus isolate was used as an inoculum. Fermentation was allowed to proceed for two weeks in the presence or absence of natural flora of lactic acid bacteria (LAB). Counts of S. aureus, LAB, and total aerobic (APC) were monitored. The fate of inoculated S. aureus (107 CFU/ml) in the presence and the absence of naturally occurring LAB showed similarity at early stage of fermentation but differ at later stage. By the end of two-week fermentation period, cOllnt of inoculated S. aureus was about one log higher (5.5) in the absence of LAB compared to in the presence (4.5). pH of all treatment, whether LAB were present or not and as well as in the sterilized Mehiawah, declined from about 5.75-5.9 to between 3.4-3.9). Physiochemical analyses of commercial samples and the survival pattern ofS. aureus suggest that Mehiawah may possess health hazards, especially under the conditions that prevail in home-made practice.