Original scientific paper

https://doi.org/10.46419/vs.53.2.3

Occurrence, enterotoxin production and antimicrobic susceptibility of Staphylococcus aureus isolates from domestic cheeses in the Dubrovnik area

Ivana Ljevaković-Musladin orcid.org/0000-0003-2744-056X ; Zavod za javno zdravstvo Dubrovnik, Dubrovnik, Hrvatska
Marina Vodnica-Martucci ; Zavod za javno zdravstvo Dubrovnik, Dubrovnik, Hrvatska
Marija Krilanović ; Zavod za javno zdravstvo Dubrovnik, Dubrovnik, Hrvatska
Lidija Kozačinski ; Veterinarski fakultet Sveučilišta u Zagrebu, Hrvatska

Abstract

Staphylococcus aureus is a well-known op¬portunistic pathogen that causes a wide range of acute and chronic diseases in both humans and animals. Staphylococcal food poisoning is just one of many diseases caused by this bacterium. The causative agents are entero¬toxins produced by enterotoxigenic strains of S. aureus during its growth in favourable conditions in food. Epidemiological data show that S. aureus is often found in raw milk cheeses and accordingly, cheeses are often implicated in food poisoning outbreaks. Since there are no data on the nature of S. aureus isolated from cheese produced in Croatia, the aim of this study was to determine the occur¬rence, enterotoxin production capability and antimicrobic susceptibility of S. aureus iso¬lates from domestic cheeses produced in the Dubrovnik area. A total of 30 cheese samples were analysed, and 18 samples (60%) were highly contaminated with S. aureus strains. The contamination level ranged from 3.94 to 6.26 log10 cfu/g. Such a high level of contami¬nation was supported by an inappropriate temperature regime above 8°C during market sale. Although highly contaminated, staphy¬lococcal enterotoxins were not detected in any of the cheese samples. A total of 180 coagu¬lase-positive isolates were collected from 18 cheese samples, 175 of which were confirmed as S. aureus by the latex agglutination test. En¬terotoxin production was detected in 35 iso¬lates (20%), and of these 32 isolates produced staphylococcal enterotoxin C. The other three isolates presumably produced enterotoxin E. Antibiotic resistance was detected in 1.1% of isolates and only to mupirocin. However, a full comprehensive conclusion on the nature of S. aureus isolates cannot be achieved with¬out determining its genotype characteristics for the presence of staphylococcal enterotoxin genes and molecular typing, to determine the origin of the isolates.

Keywords

Staphylococcus aureus; cheese; staphylococcal enterotoxins; antimicrobial susceptibility

Hrčak ID:

259362

URI

https://hrcak.srce.hr/259362

Publication date:

24.6.2021.

Article data in other languages: croatian

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