Prevalence of Antibiotic Resistome in Ready-to-Eat Salad

Abstract

Ready-to-eat salad harbors microorganisms that may carry various antibiotic resistance genes (ARGs). However, few studies have focused on the prevalence of ARGs on salad, thus underestimating the risk of ARGs transferring from salad to consumers. In this small-scale study, high-throughput quantitative PCR was used to explore the presence, prevalence and abundance of ARGs associated with serving salad sourced from two restaurant types, fast-food chain and independent casual dining. A total of 156 unique ARGs and nine mobile genetic elements (MGEs) were detected on the salad items assessed. The abundance of ARGs and MGEs were significantly higher in independent casual dining than fast-food chain restaurants. Absolute copies of ARGs in salad were 1.34 × 10 7 to 2.71 × 10 8 and 1.90 × 10 8 to 4.87 × 10 8 copies per g salad in fast-food and casual dining restaurants, respectively. Proteobacteria, Bacteroidetes, Actinobacteria, and Firmicutes were the dominant bacterial phyla detected from salad samples. Pseudomonas, Acinetobacter, Exiguobacterium, Weissella, Enterobacter, Leuconostoc, Pantoea, Serratia, Erwinia, and Ewingella were the 10 most dominant bacterial genera found in salad samples. A significant positive correlation between ARGs and MGEs was detected. These results integrate knowledge about the ARGs in ready-to-eat salad and highlight the potential impact of ARGs transfer to consumers.

Ready‐to‐eat vegetable salads served in Nigerian restaurants: a potential source of multidrug‐resistant bacteria

“…High bacterial resistance was also seen in some bacterial colonies obtained from the RTE salads, especially to antibiotics such as amoxicillin/ clavulanic acid, cotrimoxazole, gentamycin, erythromycin and chloramphenicol. The present findings agreed with the former data published by Campos et al (2013), Gurler et al (2015) and Zhou et al (2020) who, respectively, worked with RTE salads from Portugal, Turkey and China. Multiple antibiotic resistance indices of all bacterial colonies obtained from RTE salad samples (Table 2) showed that RTE salads served in these restaurants were potential sources of MRB, with significant health risk.…”

“…(2015) and Zhou et al . (2020) who, respectively, worked with RTE salads from Portugal, Turkey and China. Multiple antibiotic resistance indices of all bacterial colonies obtained from RTE salad samples (Table 2) showed that RTE salads served in these restaurants were potential sources of MRB, with significant health risk.…”

ZnO Nanoparticles-Modified Dressings to Inhibit Wound Pathogens

“…Also, studies reported ZnO NPs as potential antitumor agents, showing selective toxicity against cancer cells [ 52 ]. Nontheless, researchers should be aware of the limits of using ZnO NPs with respect to the uncontrolled Zn(II) release, which could impose certain side effects, especially when used in high concentrations and systemic therapy [ 53 ].…”

Microbial Flow Within an Air-Phyllosphere-Soil Continuum

“…Phyllosphere bacteria are a component of the plant microbiome and have an important role in facilitating plant growth, protecting crops from external pathogens ( Rasche et al, 2006 ), and mediating carbon and nitrogen cycles ( Furnkranz et al, 2008 ; Redford and Fierer, 2009 ). Potential immigrants to the phyllosphere such as Escherichia coli pose a risk to human health through the transfer of human-pathogenic bacteria from ready-to-eat food ( Teplitski et al, 2011 ; Chen et al, 2019 ; Zhou et al, 2020 ). Selection pressure is essential for structuring communities in the phyllosphere ( Yang et al, 2001 ; Kim et al, 2012 ) and is typically strong as oligotrophic conditions provide low levels of nutrients in most part of the leaves ( Lindow and Brandl, 2003 ).…”