title: Diversity and habitat specificity of free-living protozoa in commercial poultry houses.
abstract: Despite stringent biosecurity measures, infections by bacterial food pathogens such as Campylobacter are a recurrent problem in industrial poultry houses. As the main transmission route remains unclear, persistence of these infections has been linked to bacterial survival and possibly multiplication within protozoan vectors. To date, however, virtually no information is available on the diversity and occurrence of free-living protozoa in these environments. Using a combination of microscopic analyses of enrichment cultures and molecular methods (denaturing gradient gel electrophoresis [DGGE]) on natural samples, we show that, despite strict hygiene management, free-living protozoa are common and widespread throughout a 6-week rearing period in both water and dry samples from commercial poultry houses. Protozoan communities were highly diverse (over 90 morphotaxa and 22 unique phylotypes from sequenced bands) and included several facultative pathogens and known bacterial vectors. Water samples were consistently more diverse than dry ones and harbored different communities, mainly dominated by flagellates. The morphology-based and molecular methods yielded markedly different results: amoebic and, to a lesser degree, ciliate diversity was seriously underestimated in the DGGE analyses, while some flagellate groups were not found in the microscopic analyses. Some recommendations for improving biosecurity measures in commercial poultry houses are suggested.
authors.affiliation: Department of Veterinary Public Health and Food Safety, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
authors.forename: Julie
authors.initials: J
authors.lastname: Baré
authors.forename: Koen
authors.initials: K
authors.lastname: Sabbe
authors.forename: Jeroen
authors.initials: J
authors.lastname: Van Wichelen
authors.forename: Ineke
authors.initials: I
authors.lastname: van Gremberghe
authors.forename: Sofie
authors.initials: S
authors.lastname: D'hondt
authors.forename: Kurt
authors.initials: K
authors.lastname: Houf
mesh_terms: D000818:Animals; D044822:Biodiversity; D016000:Cluster Analysis; D016172:DNA Fingerprinting; D016054:DNA, Protozoan / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D004783:Environmental Microbiology; D056890:Eukaryota / Q000145:classification* / Q000166:cytology / Q000235:genetics / Q000302:isolation & purification*; D005838:Genotype; D006799:Housing, Animal; D009691:Nucleic Acid Denaturation; D011200:Poultry
chemical_list: D016054:DNA, Protozoan