Efficacy of Probiotic Lactobacillus Casei in Bio-control of Escherichia Coli O157:H7 in Nono

Abstract

is a Gram positive anaerobic rod which belongs to the lactic acid bacteria (LAB) group. It is a facultative homo-fermenter found indigenous in dairy products such as Nono and cheese. Nono is a locally fermented milk beverage consumed in Nigeria. It is a functional food which contains high numbers of Lactic acid bacteria (LAB) which includes L. casei. It is usually enjoyed with a sorghum cake known as Fura and thus it is usually called Fura D'Nono. Despite its role as a functional food, unhygienic and unaseptic milking, processing, packaging and vending procedures, could render the food product susceptible to contamination with Escherichia coli and other enteric pathogens. Escherichia coli is one of the top seven pathogens of public health concern (CDC, 2014). E. coli O157:H7 is considered an emerging disease pathogen which causes infections such as hemorrhagic gastrointestinal disease and haemolytic uremic syndrome in humans (Isibor, et al., 2013). L. casei is well-known for its wide probiotic values such as bacteriocin production, bile tolerance, acid tolerance, ability to have a good attachment to the intestinal walls, immune modulation, cholesterol regulation, non-toxicity, antibacterial activity inter alia; and has been given Generally Recognized as Safe (GRAS) status, as there has not been any established risk to humans (Gaynor, 2012). Hence adopting it in food preservation comes with an added advantage when ingested along with the food it is meant to preserve, thus boosting the health status of the end food consumers. Biopreservation or bio-control is a measure employed as an alternative to the use of chemical preservatives and antibiotics for food preservation. Thus, this research aimed at the use of L. casei as a bio-control agent against E. coli proliferation in Nono.