Microbiological contamination of reusable plastic bags for food transportation

Nowadays, with so many concerns for the environment, the use of reusable plastic bags is becoming routine, instead of the use of polluting single-use plastic bags. However, this is controversial in terms of food safety, since consumers transport many different foods, which could contaminate their bags and pose a risk to their health due to cross-contamination. This study aimed to detect or enumerate several indicators/pathogens from 30 used reusable plastic (polypropylene) bags and, to evaluate their antibiotic resistance profiles after identification by 16s rRNA of each isolated microorganism. Several genera of Enterobacteriaceae, coagulase-negative staphylococci and also Listeria monocytogenes were found in the reusable plastic bags analyzed. In general, high percentages of antibiotics resistance were found, highlighting the elevated occurrence of multi-resistant isolates of coagulase-negative staphylococci and Enterobacteriaceae. This study demonstrates the level and variety of microbial contamination of some used reusable plastic bags. No correlation was found between microbial levels and the visual appearance of each bag demonstrating that appearance is not a reliable datum about the bag contamination. We believe that this study could help the competent authorities taking measures to alert consumers to good food safety practices, not only in their kitchens, but also in the bags that carry their food.