Prevalence, enterotoxigenic potential and antimicrobial resistance of Staphylococcus aureus and methicillin resistant Staphylococcus aureus (MRSA) isolated from Algerian ready to eat foods

Staphylococcus aureus causes a foodborne intoxication due to the production of enterotoxinsand shows antimicrobial resistance, as in the case of methicillin-resistant strains (MRSA). Herein,we analyzed 207 ready-to-eat foods collected in Algeria, reporting a S. aureus prevalence of 23.2%(48/207) and respective loads of coagulase positive staphylococci (CPS) ranging from 1.00 0.5to 5.11 0.24 Log CFU/g. The 48 S. aureus isolates were widely characterized by staphylococcalenterotoxin gene (SEg)-typing and 16S-23S rDNA intergenic spacer region (ISR)-PCR, as well as bydetecting tst and mecA genes, genetic determinants of toxic shock syndrome toxin-1 and methicillinresistance, respectively. We found that the S. aureus isolates belonged to seven different SEg-typesharboring the following combinations of genes: (1) selW, selX; (2) egc (seG, seI, seM, seN, seO), selW,selX; (3) seA, seH, seK, seQ, selW, selX; (4) seB, selW, selX; (5) seD, selJ, seR, selW, selX; (6) seH, selW, selX,selY; and (7) seA, egc, selW, selX, while among these, 2.1% and 4.2% were tst- and mecA- (staphylococcalchromosomal cassette mec-type IV) positive, respectively. Selected strains belonging to the 12 detectedISR-types were resistant towards antimicrobials including benzylpenicillin, ofloxacin, erythromycin,lincomycin, tetracyclin, kanamycin, oxacillin, and cefoxitin; 8.3% (1/12) were confirmed as MRSAand 16.7% (2/12) were multidrug resistant. The present study shows the heterogeneity of the S. aureuspopulation in Algerian ready-to-eat foods as for their toxigenic potential and antimicrobial resistance,shedding the light on the quality and safety related to the consume of ready-to-eat foods in Algeria.