Enterotoxins in Staphylococcus aureus isolated from food handlers at a public market in Asunción, Paraguay

Abstract

Introduction: Staphylococcal food poisoning (SFA) is the most common foodborne toxin-borne illness in the world, but it is not a notifiable disease. Therefore, surveillance of Staphylococcus aureus carriage in food handlers is essential for outbreak prevention.
Objective: to detect enterotoxin-coding genes in S. aureus isolates collected from the nasal mucosa of food handlers from a public market in Asuncion, Paraguay in October 2023.
Methodology: descriptive observational design, cross-sectional, pilot project. Nasal swab samples were taken from 30 food handlers and cultured on blood agar and salted mannitol, the strains were identified by MALDI-TOF mass spectrometry technique. Detection of enterotoxin A, B, C, D, G, H, I, M, N, O and U genes was performed by PCR.
Results: we found a high prevalence of nasal carriage of S. aureus (40 %, 12/30) in food handlers of a public market in Asunción, with 50 % (6/12) carrying the enterotoxin M gene and other genes in smaller proportion: G, I, O, U (17 %, 2/12) and C (8 %, 1/12).
Conclusion: we report the asymptomatic nasal carriage of S. aureus carrying enterotoxins by food handlers in a public market in Asunción, whose importance lies in the severity of the clinical pictures that could be caused by the single expression of any of these virulence factors in the event of a food outbreak.