Prevalence and characterization of Bacillus cereus and Staphylococcus aureus contaminating kitchen sponges collected from domestic kitchens in Jeollanam-do, the Republic of Korea

Despite the ubiquitous usage of kitchen sponges, data regarding the occurrence and virulence of food-borne pathogenic bacteria associated with kitchen sponges in the Republic of Korea remain scarce. A total of 110 kitchen sponges obtained from randomly chosen domestic premises located in Jeollanam - do, the Republic of Korea were analyzed for the presence of food-borne pathogenic bacteria and indicator microorganisms according to the standard microbial analysis methods. The mean counts of total aerobic bacteria, coliforms, and yeasts/molds were 5.97, 2.79, and 4.05 log CFU/g, respectively, in the samples analyzed. No sample possessed Escherichia coli O157:H7, Listeria monocytogenes , and Salmonella enterica serovar Typhimurium. Qualitatively, 26 Bacillus cereus strains were isolated from 110 samples, all of which harbored at least one enterotoxin-associated gene, and 11 (42.3%) B . cereus isolates were positive for ces . B . cereus showed a complete resistance to ampicillin, amoxicillin-clavulanic acid, aztreonam, cefepime, penicillin, and rifampicin. The overall prevalence of Staphylococcus aureus among the screened kitchen sponges was 3.6%, following the enrichment step of samples, and 75.0% of the isolates contained nuc . A complete resistance against aztreonam and nalidixic acid was observed in the St . aureus isolates. • B. cereus and St. aureus were detected in 22.7% and 3.6% of samples, respectively. • B. cereus isolates possessed at least one enterotoxin-producing gene. • B. cereus and St. aureus exhibited a strong resistance profile to β-lactams. • Kitchen sponges may act as reservoirs for food-borne pathogenic bacteria.