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Cronobacter spp. (formerly Enterobacter sakazakii) can be isolated from a wide range of foods and environments, and its association with neonatal infections has drawn considerable attention from regulatory authorities. The principle route of neonatal infection has been identified as the ingestion of contaminated infant formula. A number of methods have been developed to identify Cronobacter spp., however these were before the most recent (2012) taxonomic revision of the genus into seven species. In this study, phenotyping, protein profiling and molecular methods were used to identify Cronobacter strains which had been recently isolated from ingredients used in the preparation of infant formula.Pulsed field gel electrophoresis revealed that different Cronobacter strains had been recovered from the same food products. All isolates were identified as C sakazakii according to four genus specific PCR probes and protein profiling using MALDI-TOF analysis.However, 16S rDNA sequence analyses and fusA allele sequencing gave more accurate identification: four strains were C sakazakii, one strain was C malonaticus and the remaining strain was C universalis. Multilocus sequence typing showed the strains were different sequence types.These results demonstrate the presence of different Cronobacter species in food ingredients used in the preparation of infant formula, and also the need for molecular identification and profiling methods to be revised according to taxonomic revisions.

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This study aimed to determine the antibiotic and bacteriocin sensitivity of <i>Listeria monocytogenes</i> strains isolated from animal derived foods. With disc diffusion assay, all fourteen L. <i>monocytogenes</i> strains were suscepti-ble to the antibiotics, including penicillin G, vancomycin, tetracycline, chloramphenicol, rifampicin, erythromycin, gentamicin and trime- thoprim. However, the percentages of fosfomycin and streptomycin resistances were 92.9% and 7.1%, respectively. Multiple resistances were not observed among the tested strains. The results of well diffusion assays showed that all strains were inhibited by the cell-free supernatant of a bacteriocin-producing strain, <i>Pediococcus acidilactici</i> 13, with the inhibition zones ranging from 16.00 to 24.50 mm. These results provide useful information on antibiotic resistance of L. <i>monocytogenes</i> strains isolated from foods, and can potentially be used to develop bacteriocin-based interventions to guard against the hazards associated with L. <i> monocytogenes</i> in ready-to-eat meat and poultry products

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Chicken leg and breast meat samples were inoculated with Campylobacter jejuni (ATCC 33291) at a level of 4–5 log most probable number/cm2 and dipped in lactic acid (LA; 1 and 3%) and acetic acid (AA; 1 and 2%) solutions for 10 min. Control samples were dipped in tap water. Samples were packed in polystyrene trays covered by stretch film and stored at 4C for 10 days and at−18C for 6 months. Immediately after organic acid treatments, C. jejuni counts were reduced by 0.36–1.98 log cfu/cm2 as compared to the control samples treated with tap water. C. jejuni counts decreased significantly on leg (P < 0.05) and breast meat (P < 0.01) during storage at 4C. Although the pathogen survived in all samples during 6 months of storage at−18C, its level decreased significantly (P < 0.01) in both leg and breast meat samples. It was concluded that the treatment of chicken parts with LA or AA was effective especially for reducing initial C. jejuni population. PRACTICAL APPLICATIONS Because contamination of chicken meat with Campylobacter spp. is unavoidable, there is need for a decontamination step in poultry processing. The treatment of chicken meats with lactic acid or acetic acid, which are classified as generally recognized as safe, was found advisable for reducing the initial level of Campylobacter jejuni. Additionally, this process will be beneficial for extending shelf life of chicken parts by reducing the total microbial load.