Genotypes, Exotoxin Gene Content, and Antimicrobial Resistance of Staphylococcus aureus Strains Recovered from Foods and Food Handlers

Abstract

<jats:title>ABSTRACT</jats:title><jats:p>Staphylococcal food poisoning, one of the most common food-borne diseases, results from ingestion of one or more staphylococcal enterotoxins (SEs) produced by<jats:named-content content-type="genus-species">Staphylococcus aureus</jats:named-content>in foods. In the present study, 64<jats:named-content content-type="genus-species">S. aureus</jats:named-content>isolates recovered from foods and food handlers, associated or not associated with food-poisoning outbreaks in Spain, were investigated. They were assigned to 31 strains by<jats:italic>spa</jats:italic>typing, multilocus sequence typing (MLST), exotoxin gene content, and antimicrobial resistance. The strains belonged to 10 clonal complexes (CCs): CC5 (29.0%), CC30 (25.8%), CC45 (16.1%), CC8, CC15 (two strains each), CC1, CC22, CC25, CC59, and CC121 (one strain each). They contained hemolysin genes (90.3%);<jats:italic>lukED</jats:italic>(77.4%); exfoliatin genes<jats:italic>eta</jats:italic>,<jats:italic>etd</jats:italic>(6.5% each), and<jats:italic>etb</jats:italic>(3.2%);<jats:italic>tst</jats:italic>(25.8%); and the following enterotoxin or enterotoxin-like genes or clusters:<jats:italic>sea</jats:italic>(38.7%),<jats:italic>seb</jats:italic>(12.9%),<jats:italic>sec</jats:italic>(16.1%),<jats:italic>sed-selj</jats:italic>with or without<jats:italic>ser</jats:italic>(22.9%),<jats:named-content content-type="genus-species">selk-selq</jats:named-content>(6.5%),<jats:italic>seh</jats:italic>,<jats:italic>sell</jats:italic>,<jats:italic>selp</jats:italic>(9.7% each),<jats:italic>egc1</jats:italic>(32.3%), and<jats:italic>egc2</jats:italic>(48.4%). The number of<jats:italic>se</jats:italic>and<jats:italic>sel</jats:italic>genes ranged from zero to 12. All isolates carrying<jats:italic>tst</jats:italic>, and most isolates with genes encoding classical enterotoxins (SEA, SEB, SEC, and SED), expressed the corresponding toxin(s). Two CC5 isolates from hamburgers (<jats:italic>spa</jats:italic>type t002, sequence type 5 [ST5];<jats:italic>spa</jats:italic>type t2173, ST5) were methicillin resistant and harbored staphylococcal cassette chromosome<jats:italic>mec</jats:italic>(SCC<jats:italic>mec</jats:italic>) IVd. Six (19.4%) were mupirocin resistant, and one (<jats:italic>spa</jats:italic>type t120, ST15) from a food handler carried<jats:italic>mupA</jats:italic>(MIC, 1,250 μg/ml). Resistance to ampicillin (<jats:italic>blaZ</jats:italic>) (61.3%), erythromycin (<jats:italic>ermA-ermC</jats:italic>or<jats:italic>ermC</jats:italic>) (25.8%), clindamycin (<jats:italic>msrA-msrB or msrB</jats:italic>) (16.1%), tetracycline (<jats:italic>tetK</jats:italic>) (3.2%), and amikacin-gentamicin-kanamycin-tobramycin (<jats:italic>aphA</jats:italic>with<jats:italic>aacA</jats:italic>plus<jats:italic>aphD</jats:italic>or<jats:italic>aadD</jats:italic>) (6.5%) was also observed. The presence of<jats:named-content content-type="genus-species">S. aureus</jats:named-content>strains with an important repertoire of virulence and resistance determinants in the food chain represents a potential health hazard for consumers and merits further observation.</jats:p>

Methicillin-resistant <i>Staphylococcus aureus</i> isolates from Iranian restaurant food samples: Panton-Valentine Leukocidin, SCCmec phenotypes and antimicrobial resistance

“…Prevalence of methicillin-resistant S. aureus (MRSA) strains is 50 % in various types of hospital infections [6,7]. Resistance of bacterial strains against antibiotics mainly occurred by presence of antibiotic resistance genes [8].…”

Panton-Valentine Leukocidin-Positive Staphylococcus aureus in Ireland from 2002 to 2011: 21 Clones, Frequent Importation of Clones, Temporal Shifts of Predominant Methicillin-Resistant S. aureus Clones, and Increasing Multiresistance

“…Isolates that exhibited phenotypic resistance to particular antimicrobial agents for which associated resistance genes were not detected by the DNA microarray, or for which resistance genes were detected but partial or none of the associated resistance phenotypes were detected, were further investigated by PCR to confirm the presence or absence of these resistance genes. These investigations included PCRs using previously described primers to detect mupA (36), aphA3 (37), aacA-aphD (37), fusB (38), tet(K) (36), tet(M) (36), aadD (39), and qacA (40), and also novel primers to detect qacC, msr(A), dfrS1, lnu(A), mph(C), and blaZ (see Table S1 in the supplemental material).…”

Microbial quality of industrial and retail market grated parmesan cheese in the State of São Paulo, Brazil

“…The assessment of Staphylococcus in food is critical as over 20 its species can cause several diseases in humans (KANDARIYA et al, 2014). Moreover, Staphylococcus is one of the most common causes of foodborne illnesses (SCALLAN et al, 2011) and is the main source of contamination in inadequately handled food (ARGUDÍN et al, 2012).…”