Molecular epidemiological survey of Listeria monocytogenes in broilers and poultry products

Abstract

Aims: To investigate the prevalence of Listeria monocytogenes in poultry products, and to elucidate whether poultry products may be linked to listeriosis cases. A further goal was to identify contamination routes for L. monocytogenes to broiler carcasses. Methods and Results: Poultry products (385 samples) were screened for L. monocytogenes. The recovered isolates and 19 patient isolates were characterized by multilocus enzyme electrophoresis and restriction enzyme analysis. The poultry isolates showed great genetic diversity, but no identical subclones were identified from poultry sources and patients. One slaughterhouse was examined in detail during a 16-month period. The contamination rates increased along the processing line, and one subclone was found during the whole period. Only low prevalence of the bacteria was revealed from broiler faeces. Conclusions: The prevalence of L. monocytogenes in poultry products was high, but no listeriosis cases was linked to poultry products. Broilers seem to be contaminated during the slaughter process, and specific strains may persist in the processing environment. Broiler faeces does not seem to be an important source of L. monocytogenes in poultry products. Significance and Impact of the Study: Preventive measures to avoid contamination of poultry products by L. monocytogenes must be taken in the processing plants.

Diversity of Listeria Species in Urban and Natural Environments

“…All statistically significant spatial clusters of Listeria species and sigB allelic represented isolates from samples obtained at multiple and in some cases all sampling dates, further supporting that these clusters represent area-specific persistent populations. These findings are consistent with a number of studies that have indicated that specific Listeria subtypes can establish persistent populations in food-processing and retail environments (41,52,56), including some instances where a given subtypes seems to have persisted in a specific plant for at least 12 years (34). We propose that the ability of members of the genus Listeria to establish persistent populations in different environments is critical for its widespread and ubiquitous presence.…”

Microbiological quality of broiler carcasses during slaughter processing

“…A number of authors mention frequent findings of Listeria spp. both on poultry carcass surfaces and in the slaughterhouse itself, particularly at the end of the slaughter line (Rørvik et al 2003). The authors hypothesize that the incidence of L. monocytogenes increases particularly during evisceration and in some other sections of the line, such as the packing or cutting of birds.…”

Detection of Listeria Spp. During Production and Ripening of Petrovská Klobása/Detekcija Listeria Spp. U Toku Proizvodnje I Zrenja Petrovačke Kobasice

“…both on poultry carcasses and in the slaughterhouse itself, particularly at the end of the slaughter line [16]. Miettinen et al, [17] assumed that increased contamination with L. monocytogenes occurs after chilling when carcasses are cut up and, mainly, when their skin is removed.…”