P40 Kitchen sponges—home sweet home for carbapenem-resistant Klebsiella spp.

BACKGROUND: Although research on foodborne diseases is well documented for certain microorganisms, less research has been undertaken on cross-contamination with Enterobacteriaceae from food within the kitchen environment. In this study, we analysed the presence of Klebsiella spp. and Raoultella spp. and their antibiotic resistance in 100 used kitchen sponges. In a domestic environment, kitchen sponges are commonly used by consumers for doing the dishes and/or cleaning kitchen surfaces. Given their multipurpose use, their often high humidity and presence of organic residuals they are considered a favourable habitat for various groups of microorganisms and could serve as a vehicle in transmission of foodborne pathogens.(1,2) MATERIAL AND METHODS: A total of 100 kitchen sponges alongside a questionnaire regarding hygienic parameters were randomly collected from domestic environments and analysed within 24 h after arrival in the lab. Kitchen sponges were immersed in 100 mL buffered peptone water, homogenized and incubated at 37°C for 24 h ± 2 h. Ten microlitres of this enrichment was plated on MacConkey agar (Bio-Rad) and incubated at 37°C for 24 h ± 2 h. Presumptive Klebsiella spp. and Raoultella spp. were isolated and confirmed by MALDI-TOF MS. Antibiotic resistance testing (ART) was performed on all Klebsiella spp. and Raoultella spp. isolates following the EUCAST guidelines. WGS was performed using the Illumina platform. RESULTS: A total of 65% of the kitchen sponges were positive for Klebsiella spp. or Raoultella spp. The species Klebsiella oxytoca was detected in 78.5% of positive samples, followed by Klebsiella pneumoniae (12.31%), Raoultella ornithinolytica (4.62%), Klebsiella variicola (1.54%), Klebsiella aerogenes (1.54%) and Raoultella planticola (1.54%). To the best of our knowledge this is the first study performed on detection of Klebsiella spp. in kitchen sponges from Belgium and has comparable results with previous studies.(1–3) We hypothesize the high positivity rate is caused by cross-contamination. ART revealed the presence of one carbapenem-resistant isolate, with resistance to ertapenem and meropenem. Reduced susceptibility to carbapenems was caused by the presence of bla(SHV-36) combined with porin deficiency. Klebsiella spp. can be part of the commensal flora of human intestines but are considered to be opportunistic pathogens. Klebsiella spp. might present antimicrobial resistance and carbapenem-resistant Enterobacteriaceae are taken up in the WHO global priority list of antibiotic-resistant bacteria. CONCLUSIONS: High prevalence of Klebsiella spp. and a carbapenem-resistant isolate in kitchen sponges highlight the occurrence of cross-contamination from food and the possible risks for foodborne disease associated with this kitchen tool. These findings advocate for good hygienic measures within a household setting.