Molecular Study of Enterotoxin Genes of Staphylococcus aureus Isolated Locally from Al-Diwaniyah City

Abstract Background: Following Salmonella , Staphylococcus aureus has been identified as the second most frequent origin of foodborne disease outbreaks. It was discovered that there are five main forms of enterotoxins, named the classic staphylococcal enterotoxin A, staphylococcal enterotoxin B, staphylococcal enterotoxin C, staphylococcal enterotoxin D, and staphylococcal enterotoxin E. Objectives: This study aims to isolate S. aureus and, then, study the molecular characterization of the enterotoxin genes that these bacteria possess by using the polymerase chain reaction (PCR) technique to determine the epidemiology of these genes. Materials and Methods: A total of 280 samples were collected from two different sources from December 1, 2019, to October 1, 2020, and distributed to 200 stool specimens from consulting Al-Diwaniyah clinics, Maternity and Children Teaching Hospital, and health centers, and the additional source of samples contained 80 samples of dairy items. Results: The findings revealed that there number of S. aureus was 15 isolates representing (20.83%) in samples of dairy ingredients, whereas it was discovered that (9.03%) of the all-inclusive was isolated from the stool of patients. S. aureus isolated from both origins had enterotoxin genes by utilizing the PCR technique, S. aureus isolates in both origins were characterized by a 100% presence of the sea gene, while the seb gene present with percentage (33%) and (40%), respectively, for milk and stool samples. In contrast, S. aureus isolates from both sources did not appear to contain genes of other enterotoxins, which include sec , sed , and see . Conclusion: It was found that the toxic metabolites that enable S. aureus bacteria to produce enterotoxins are genetically encoded and represented by the sea and seb genes, sea is the most prevalent compared with other genes followed by the seb gene.