Listeria monocytogenes is common in wild birds in Helsinki region and genotypes are frequently similar with those found along the food chain.
OBJECTIVE
To evaluate the prevalence and genetic diversity of Listeria monocytogenes in wild birds and to compare the genotypes with isolates previously collected from foods and food processing environments.


RESULTS
Samples of wild birds' faeces (n = 212) were collected from a municipal landfill site and from urban areas in the Helsinki region and analysed by two-step enrichment and plating onto L. monocytogenes-selective agar. The overall prevalence of L. monocytogenes in bird faeces was 36% (95% CI 30-43%), and prevalence on the landfill site was significantly higher. All isolates were analysed with pulsed-field gel electrophoresis and compared with the L. monocytogenes profiles in an existing collection. Similar pulsotypes were found in birds and in isolates collected along the food chain.


CONCLUSIONS
Birds commonly carry L. monocytogenes, and strains are frequently similar with those detected in foods and food processing environments. Thus, birds may disseminate L. monocytogenes in nature and may also contaminate foods when entering the food processing environments and outdoor market places.


CONCLUSIONS
Populations of L. monocytogenes in wild birds and along the food processing chain overlap. Our findings add to the epidemiological data on this significant foodborne pathogen.
Hellström
S
S
Department of Food and Environmental Hygiene, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland. sanna.hellstrom@helsinki.fi
Kiviniemi
K
K
Autio
T
T
Korkeala
H
H
D000818:Animals; D001717:Birds / Q000382:microbiology*; D004197:Disease Reservoirs; D016521:Electrophoresis, Gel, Pulsed-Field; D004783:Environmental Microbiology; D005243:Feces / Q000382:microbiology; D005387:Finland; D020387:Food Chain; D005516:Food Microbiology; D005525:Food-Processing Industry; D005838:Genotype; D006801:Humans; D008089:Listeria monocytogenes / Q000235:genetics / Q000302:isolation & purification*; D008088:Listeriosis / Q000635:transmission; D018505:Waste Management