The bacteriological status of retail cheese in Zagazig city, Egypt

Abstract

Cheese is one of the most popular dairy products in Egypt. It supplies the body with protein, fat, vitamins and minerals. Cheese may be exposed to bacterial contamination during manufacture, distribution and/or storage. This study was undertaken to investigate the bacteriological status of different cheese types marketed in Zagazig city, Egypt. The obtained results showed that Roumy cheese had the highest total mesophilic and psychrophilic counts followed by white, soft and cheddar cheese types. Furthermore, the coliforms count and prevalence of different serotypes of E. coli in cheese samples were detected. In addition, the expression of shiga-toxin producing genes (stx1 & stx2) in the identified E. coli serotypes was screened using multiplex PCR. The obtained results revealed that only E. coli O127:H6 had expressed both stx1 & stx2 toxin producing genes, while E. coli O111:H4 had expressed only stx1 gene, however, both E. coli O124: H and O55:H7 had expressed stx2 gene. The public health importance of shiga-toxin producing E. coli was detected.