Phylogeny characterization of seb gene encoding enterotoxins in staphylococcus aureus isolated from raw milk and cheese

Abstract

Food poisoning due to the bacteria is a big global problem in economically and human’s health. This problem refers to an illness that is due to infection or the toxin that exists in nature and the food that use. Milk is considered a nutritious food because it contains proteins and vitamins. The aim of this study is to detect and phylogeny characterization of staphylococcal enterotoxin B gene (Seb). A total of 200 milk and cheese samples were screened. One hundred ten isolates of Staphylococcus aureus pre-confirmed using selective and differential media with biochemical tests. Genomic DNA was extracted from the isolates, and the SEB gene detects using conventional polymerase chain reaction (PCR) with specific primers. Three Staphylococcus aureus isolates were found to be positive for the Seb gene using PCR and confirmed by sequencing. Sequence homology showed a variety range of identity, starting from (100% to 38%). Phylogenetic tree analyses show that samples (6 and 5) are correlated with S. epidermidis. This study discovered that isolates (A6-RLQ and A5-RLQ) are significantly clustered in a group with non-human pathogen Staphylococcus agnetis.