Isolation and molecular identification of enterotoxin production genes of Staphylococcus aureus from raw cow's milk

Subject Areas : Journal of Comparative Pathobiology

Hamideh Jalaliani ¹ , Seyed Amir Ali Anvar ² , k Amini ³ , Gh Karim ⁴

1 - Department of Food Hygiene, Science and Research Branch, Islamic Azad University, Tehran, Iran
2 - Department of Food Hygiene, Science and Research Branch, Islamic Azad University, Tehran, Iran
3 - Department of Food Hygiene, Islamic Azad University, Science and Research Branch, Tehran, Iran.
4 - Department of Food Hygiene, Tehran University, Tehran, Iran

Received: 2024-10-29 Accepted : 2024-12-30 Published : 2024-12-20

Keywords: Milk, Staphylococcus aureus, enterotoxin,

Abstract :

This study aims to investigate the prevalence of enterotoxin production among Staphylococcus aureus isolates from raw cow's milk using molecular identification and gene isolation techniques. This laboratory-based study involved the collection of 100 raw cow's milk samples (200 ml each) from dairy production centers and livestock farms in Tehran province, Iran. Standard biochemical methods and heat staining were employed for staphylococcal identification and isolation. Multiplex PCR was performed on samples containing Staphylococcus aureus isolates to assess enterotoxin production, specifically targeting SEA-SEE enterotoxins. Among the 100 milk samples analyzed, 60 staphylococcal strains were isolated. Molecular analysis revealed the presence of enterotoxin genes in the genomes of 54 strains. Three samples exhibited the highest levels of superantigens. The distribution of enterotoxin genes among the isolates was as follows: 10 with SEA, 5 with SED, 4 with SEE, 1 with SEB, 7 with SEC, 2 with SEC and SEA, and 1 with SEE and SEA. The findings of this study underscore the prevalence of Staphylococcus aureus enterotoxins in raw cow's milk, particularly in the context of rising antimicrobial resistance. Analyzing the distribution of enterotoxin genes in Staphylococcus aureus provides valuable epidemiological insights for enhancing public health and food safety. The implementation of epidemiological studies based on comprehensive molecular investigations, such as Multiplex PCR, holds promise in curbing the spread of pathogenic and infectious bacteria.

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