Occurrence of phoA and Shiga Toxin genes in Marketed Gandoffli, Ruditapes decussates

Abstract

Generally, the majority of the food poisoning crisis from seafood comes out due to shellfish consumption, mainly gandofflibecause ofits filter feeders pattern. Many microbes are used as an indicator of the hygienic status of several foods, one of them is Escherichia coli which is used to detect fecal pollution in water and shellfish. Therefore, twenty gandoffli samples were randomly collected from local markets in Ismailia city, Egypt, for evaluation of Enterobacteriaceae counts, and identification of Escherichia. coli and detection of phoA and Shiga toxin genes. The obtained results revealed that the total Enterobacteriaceae count of the gandoffli ranged from 7×10² to 7×10⁵ cfu/g with an average of 5×10⁴ ±3.5×10⁴cfu/g. The occurrence of Enterobacteriaceae members in gandoffli was represented by E. coli (99%), Acinetobacter lwoffii (99%), Enterobacter hormaechei (85%), Klebsiella oxytoca (95%), Stentrophomonas maltophilia (85%), Moraxella lacunata (85%), Achromobacter xyloxidans (93%), and ESBL E. coli (100%). In addition, E. coli isolated from gandoffli were subsequently serologically typed into O_103, O_55, O _128, O _126, and O₁₅₇ then confirmed using conventional polymerase chain reaction by the presence of alkaline phosphatase gene. Upon checking virulence genes in E. coli: stx₂ was absent in O₁₅₇ and O_103. Also, stx₁ was present in O₁₅₇ and absent in O₁₀₃. Its should be concluded that gandoffli were exposed to enterobacteriaceae contamination from different sources during handling, storage and distribution. Gandoffli had E coli and their toxin that can pose serious public health hazards to consumers. Strick hygienic measures must be applied through the chain of gandoffli production to ensure their safety for consumer consumptions