Behaviour of co-inoculated pathogenic and spoilage bacteria on poultry following several decontamination treatments

Prevalence, Molecular Typing, and Determination of the Biofilm-Forming Ability of Listeria monocytogenes Serotypes from Poultry Meat and Poultry Preparations in Spain

A study was undertaken of the presence of Listeria monocytogenes in 260 samples of poultry meat obtained from retail outlets in northwestern Spain. L. monocytogenes was detected in 20 samples (7.7%). Twenty strains (one strain per positive sample) were characterized. The strains belonged to 10 serotypes: 1/2a (2 strains), 1/2b (2), 1/2c (2), 3a (1), 3b (2), 3c (2), 4a (2), 4b (4), 4c (1), and 4d (2). Cluster analysis (ribotyping; EcoRI) showed a strong genetic relationship between strains isolated from samples coming from different outlets. Ribotyping permitted some isolates of the same serotype to be differentiated, which points to the possible usefulness of this technique in the epidemiological surveillance of L. monocytogenes. All strains formed biofilm on polystyrene, as shown by confocal laser scanning microscopy. The biovolume (between 621.7 ± 36.0 µm3 and 62,984.0 ± 14,888.2 µm3 in the observational field of 14,161 μm2), percentage of surface coverage (from 2.17 ± 0.84% to 94.43 ± 3.97%), roughness (between 0.399 ± 0.052 and 0.830 ± 0.022), and maximum thickness (between 9.00 ± 0.00 µm and 24.00 ± 14.93 µm) of biofilms varied between strains (p < 0.05). These results expand knowledge of the characteristics of L. monocytogenes isolates from poultry.

Bacterial Contaminants of Poultry Meat: Sources, Species, and Dynamics

With the constant increase in poultry meat consumption worldwide and the large variety of poultry meat products and consumer demand, ensuring the microbial safety of poultry carcasses and cuts is essential. In the present review, we address the bacterial contamination of poultry meat from the slaughtering steps to the use-by-date of the products. The different contamination sources are identified. The contaminants occurring in poultry meat cuts and their behavior toward sanitizing treatments or various storage conditions are discussed. A list of the main pathogenic bacteria of concern for the consumer and those responsible for spoilage and waste of poultry meat is established.

Effect of the temperature of the dipping solution on the antimicrobial effectiveness of various chemical decontaminants against pathogenic and spoilage bacteria on poultry

The influence of the temperature of the dipping solution on the antimicrobial effectiveness of several chemical poultry decontaminants was assessed. A total of 765 poultry legs were inoculated with gram-positive bacteria (Listeria monocytogenes, Staphylococcus aureus, Bacillus cereus, or Brochothrix thermosphacta) or gram-negative bacteria (Salmonella enterica serotype Enteritidis, Escherichia coli, Yersinia enterocolitica, or Pseudomonas fluorescens). Samples were dipped for 15 min in solutions (wt/vol) of trisodium phosphate (12%), acidified sodium chlorite (1,200 ppm), citric acid (2%), peroxyacids (220 ppm), chlorine dioxide (50 ppm), or tap water or were left untreated (control). The temperatures of the dipping solutions were 4, 20, or 50°C. Microbiological analyses and pH determinations were carried out after 0, 1, 3, and 5 days of storage at 4°C. In comparison with the control samples, all chemical solutions were effective for reducing microbial loads. The temperature of treatment affected the microbial reductions caused by all chemicals (P < 0.001). The lowest average bacterial reductions caused by trisodium phosphate, acidified sodium chlorite, citric acid, and peroxyacids were observed at 4°C, all sampling days and microbial groups being considered simultaneously. The highest and the lowest effectiveness for chlorine dioxide were observed at 4 and 50°C, respectively. These results may be of use to meat processors for selecting the best conditions for decontamination treatments and may help the European Regulatory Authorities make their decisions for authorization of poultry decontamination treatments.