Listeria spp. are Gram-positive and facultative anaerobic bacteria, with a low G+C content in their genetic material. The genus comprises six species, namely Listeria monocytogenes, Listeria ivanovii, Listeria seeligeri, Listeria innocua, Listeria welshimeri, and Listeria grayi. The only pathogenic species of this genus is L. monocytogenes, although there have been few reports on the capability...

The occurrence of Listeria monocytogenes has been widely investigated in the poultry production chain from the processing plant to the final product. However, limited data are available on Listeria species, including Listeria monocytogenes, in the poultry farm environment. Therefore, fecal and soil samples from 37 pastured poultry flocks from 10 all-natural farms over 3 years were assessed to d...

Aerosol studies of Listeria monocytogenes in food processing plants have been limited by lack of a suitable surrogate microorganism. The objective of this study was to investigate the potential of using green fluorescent protein-labeled strains of Listeria innocua as a surrogate for L. monocytogenes for aerosol studies. These studies were conducted in a laboratory bioaerosol chamber and a pilot...

A total of 336 Listeria isolates from ready-to-eat (RTE) meat products and meat-processing environments, consisting of 206 Listeria monocytogenes, and 130 Listeria innocua isolates, were characterized by disc diffusion assay and minimum inhibitory concentration (MIC) values for antimicrobial susceptibility against twenty antimicrobials. Resistance to one or two antimicrobials was observed in 71...

More than 98% of reported human listeriosis cases are caused by specific serotypes within genetic lineages I and II. The genome sequence of Listeria monocytogenes lineage III strain HCC23 (serotype 4a) enables whole genomic comparisons across all three L. monocytogenes lineages. Protein cluster analysis indicated that strain HCC23 has the most unique protein pairs with nonpathogenic species Lis...

A total of 154 samples of marine (n=51) and freshwater fish (n=103) were obtained from fish markets in Elazig Province of eastern Turkey. These samples were tested for Campylobacter, Listeria and Salmonella using culturing and biochemical methods. Campylobacter failed to be detected in any freshwater or marine fish samples. Listeria was detected in 22 and 14 of gill and skin samples from freshw...

The genus Listeria contains the two pathogenic species Listeria monocytogenes and Listeria ivanovii and the four apparently apathogenic species Listeria innocua, Listeria seeligeri, Listeria welshimeri, and Listeria grayi. Pathogenicity of the former two species is enabled by an approximately 9 kb virulence gene cluster which is also present in a modified form in L. seeligeri. For all Listeria ...

A study was undertaken on the presence and frequency of Listeria sp. in feces from 1,000 patients suffering from diarrheal diseases and from 2,000 healthy persons. Furthermore, the feces of patients were examined for other well-documented enteropathogens such as Campylobacter, Salmonella, Shigella, Staphylococcus aureus, Yersinia enterocolitica, protozoa and rotavirus as well as for organisms o...

Listeria innocua is widespread in the environment and in food. This species has to date never been described in association with human disease. We report a case of fatal bacteremia caused by L. innocua in a 62-year-old patient.

In the last decade, atypical Listeria monocytogenes and L. innocua strains have been detected in food and the environment. Because of mutations in the major virulence genes, these strains have different virulence intensities in eukaryotic cells. In this study, we performed phenotypic and genotypic characterization of atypical L. monocytogenes and L. innocua isolates obtained from swine slaughte...