Safety-related properties of staphylococci isolated from food and food environments

Abstract

Aims: To test some safety-related properties within 321 staphylococci strains isolated from food and food environments. Methods and Results: The isolates were identified as Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus saprophyticus, Staphylococcus pasteuri, Staphylococcus sciuri, Staphylococcus warneri and Staphylococcus xylosus. Decarboxylase activity was quite common for the various Staphylococcus spp., and tyrosine was the most frequently decarboxylated amino acid. The frequency of antibiotic resistance was highest in Staph. pasteuri and Staph. xylosus. Several of the isolates were tolerant to QAC compounds, and in some cases, QAC tolerance was present in antibiotic-resistant strains. Most of the strains displayed moderate to high adhesion rates to stainless steel and Teflon. The strains that readily formed biofilms belonged to the species Staph. aureus, Staph. epidermidis and Staph. pasteuri. Conclusions: An high incidence of some safety hazards was found within the staphylococcal strains of food origin tested in this study. In particular, amino acid decarboxylase activity and biofilm-forming ability were common within strains, and antibiotic resistance and tolerance to QAC-based compounds occurred frequently as well. These characteristics are an important safety concern for food industry. Significance and Impact of the Study: This work gives a first picture of safety hazards within staphylococcal species isolated from food environments. The presence of disinfectant-resistant staphylococci is a concern because resistance can be genetically transferred between the various Staphylococcus species. This could lead an increase and spread of resistant enterotoxic staphylococci and . or pathogenic staphylococci

Incidence of Staphylococcus aureus and Analysis of Associated Bacterial Communities on Food Industry Surfaces

“…These results agree with previous reports in which the incidence of antibiotic resistance among S. aureus strains isolated from food was not remarkably high, excluding penicillin (26). In contrast, a number of studies found that S. aureus from different foods showed relatively high incidence rates of resistance to different antibiotics (44).…”

Eugenol inhibits quorum sensing and biofilm of toxigenic MRSA strains isolated from food handlers employed in Saudi Arabia

“…Since little information is available regarding staphylococcal biofilms in the food environment, isolated MRSA were screened for biofilm formation. Our findings find support from the observation made by Marino et al [29] who showed moderate to high biofilm formation among staphylococci isolated from food samples and food handlers. The ability of food pathogens like S. aureus to adhere to an abiotic surface and form a biofilm in food environments may ultimately lead to food poisoning [30].…”

“…Results obtained from investigation of MRSA isolates were in accordance with the findings of Dagnew et al [6] who reported 9.8% methicillin resistance among the isolated S. aureus from food handlers in Ethiopia. Detection of MRSA in the present study is vital because food handlers carrying MRSA have been identified as major cause of community-acquired foodborne outbreaks [28,29] Screening for biofilm formation Biofilm formation capacity of the MRSA strains was evaluated by CRA method and microtiter plate method (Figure 2(A,B)). In CRA method, six S. aureus isolates were positive for biofilm formation, showing black coloration of the colony.…”

Inactivation of Foodborne Bacteria Biofilms by Aqueous and Gaseous Ozone

“…Biofilms are made of microorganisms adhered to and growing on a surface and are a prevalent mode of growth for microorganisms: in this form, they are enclosed in extracellular polymeric substances (EPS) which protect cells against adverse environmental conditions, especially antimicrobials. Several food spoilage and pathogenic bacteria have been reported to attach and form biofilms on different food contact surfaces, and biofilms have become challenging in a wide range of food industries, such as dairy plants (Stellato et al, 2015), fish and seafood processing areas (Takahashi et al, 2009), meat and poultry processing (Liu et al, 2015), catering establishments (Marino et al, 2011) as well as fermented beverages plants (Maifreni et al, 2015). Major food pathogens, such as Listeria monocytogenes , Staphylococcus aureus , and Escherichia coli , can form biofilms and so become a significant threat to consumers’ health (Dourou et al, 2011; Ferreira et al, 2014).…”