Microbiological Quality of Domiati Cheese and the Influence of Probiotics on the Behavior of Staphylococcus aureus and Escherichia coli O157:H7 in Domiati Cheese

Abstract

The objectives of this study were to assess the microbiological quality of domiati cheese and to evaluate the capacity of Lactobacillus acidophilus La-5 and Bifidobacterium longum ATCC15707 to inhibit the growth of Staphylococcus aureus and Escherichia coli O157:H7 during manufacture and storage of domiati cheese. The results of the microbial investigation indicated poor microbiological quality of cheese samples, the microbiological parameters recorded higher values than admissible levels. Domiati cheese produced from milk artificially contaminated with S. aureus and E. coli O157:H7 was used as a model for studying the antibacterial activity of L. acidophilus La-5 and B. longum ATCC15707 against these pathogens. The results obtained in this study indicated the remarkable effect of L. acidophilus La-5 and B. longum ATCC15707 in preventing survival of S. aureus and E. coli O157:H7 during cheese storage. The inactivation rate was more pronounced with S. aureus than E. coli O157:H7 and it was dependent on probiotic strain. L. acidophilus inactivation was significantly higher (P value < 0.05) than that attained with B. longum. Survival of probiotic bacteria in domiati cheese was satisfactory. PRACTICAL APPLICATIONSThe microbial contamination of domiati cheese represents not only spoilage of the product but also constitutes a high risk to human health. The probiotic bacteria have the ability to improve the microbiological quality and safety of domiati cheese. Survival of both Lactobacillus acidophilus La-5 and Bifidobacterium longum ATCC15707 in domiati cheese was satisfactory, which indicate that the domiati cheese would be a suitable vehicle for the delivery of probiotic bacteria.

Physicochemical, microbiological and spoilage analysis of probiotic processed cheese analogues with reduced emulsifying salts during refrigerated storage

“…Aly et al (2007) and Meshref and Hassan (2009) found 52.5 and 78 % of the cheese samples were contaminated with coliforms, respectively. El-Kholy et al (2014) explained high counts of coliforms in cheese may occasionally provide an increased risk for early blowing or gassing of the product, which can be observed by large gas holes and a spongy texture of the cheese during the initial days of manufacturing. Presence of high counts of molds and yeasts in cheese can be also related to the unsanitary practices during cheese making, insufficient conditions of utensils, unacceptable controlling of pasteurization process and the use of low-quality milk and ingredients (Coveney et al 1994).…”

Selection and identification of protective culture for controlling Staphylococcus aureus in fresh Domiati like cheese

“…It was observed that the hygienic quality of most of Domiati cheese, which collected from dairy shops in Egypt, was not met the Egyptian Standard and could be a source of health risk. The publications showed that S. aureus was detected in most Domiati cheese samples, which collected from various dairy shops, street vendors, and supermarkets located in different governorates in Egypt such as Aswan, Gharbia, Beni‐Suef, and Cairo (Eid & Eltalawy, ; El‐Kholy, El‐Shinawy, Meshref, & Korany, ; Ibrahim, Sharaf, & El‐Khalek, ; Malt, ). Although S. aureus was found in raw milk, the presence of S. aureus in Domiati cheese is usually due to unhygienic handling of the product and/or an extensive contamination by personnel possibly involved in cheese during making and marketing (El‐Kholy et al, ).…”

“…The publications showed that S. aureus was detected in most Domiati cheese samples, which collected from various dairy shops, street vendors, and supermarkets located in different governorates in Egypt such as Aswan, Gharbia, Beni‐Suef, and Cairo (Eid & Eltalawy, ; El‐Kholy, El‐Shinawy, Meshref, & Korany, ; Ibrahim, Sharaf, & El‐Khalek, ; Malt, ). Although S. aureus was found in raw milk, the presence of S. aureus in Domiati cheese is usually due to unhygienic handling of the product and/or an extensive contamination by personnel possibly involved in cheese during making and marketing (El‐Kholy et al, ). So the control of S. aureus in Domiati cheese making is an important issue, not only as economic impact for dairy industry but also as significant public health.…”

“…by personnel possibly involved in cheese during making and marketing (El-Kholy et al, 2014). So the control of S. aureus in Domiati cheese making is an important issue, not only as economic impact for dairy industry but also as significant public health.…”

Prevalence, molecular characterization of Staphylococcus aureus isolated from cheese and in vitro antibacterial activity of silver nanoparticles against such strains

“…Damietta cheese is the most popular type of pickled soft cheese by all socioeconomic classes in Egypt due to its nutritional value, convenience and good taste. Fully ripened Damietta cheese has strong, sharp flavor, as well as smooth body and texture [ 1 ]. Furthermore, Kareish cheese is considered as one of the most popular local types of fresh soft cheese in Egypt.…”