Abstract

Background:
Staphylococcus bacteria-induced food poisoning is considered one of the most prevalent foodborne infections worldwide. The neutral pH of milk and abundance of nutrients support the growth of various bacteria.

Aim:
The goals of this study are to detect the nuc, coa, and 16S rRNA genes, find the sea, seb, and sec genes in coagulase-negative Staphylococcus aureus (CNSA), and compare the local strains with those from previous studies.

Methods:
Sixty samples of buffaloes with subclinical mastitis were obtained from numerous regions of Nineveh Province. Classical and molecular biology methods used for isolating and identifying of Staphylococcus aureus.

Results:
The results indicated that 13.3% (8/60) of buffalo milk contained isolated CNSA. While no CNSA isolates were discovered in Kobae, the highest percentage of CNSA isolates were observed in the Kaneitra Haoy, Al-Kaneesa, and Bosiif regions. Furthermore, the polymerase chain reaction (PCR) approach revealed that all CNSA isolates possessed the nuc and 16S rRNA genes (100%, 8/8); nevertheless, no CNSA isolates had the coa, sea, seb, or sec genes. The The National Center for Biotechnology Information GenBank database contains 7 newly discovered 16S rRNA gene sequences of S. aureus. These sequences are accessible with accession codes PV330711, PV330712, PV330713, PV330714, PV330715, PV330716, and PV330717. Furthermore, the newly isolated S. aureus sequences in this study are related to other S. aureus sequences isolated from various countries.

Conclusion:
CNSAs as mastitis-causing agents cannot be ignored as they can cause significant economic losses. The PCR method can be used to identify the virulence factors of CNSA isolates that help in determining the prevalence, severity, and implementation of control and prevention measures.

Key words: Buffalo milk; Coagulase negative S. aureus; Phylogenetic analysis; Staphylococcal enterotoxins genes.