Species diversity of campylobacteria in a wild bird community in Sweden.

AIMS: To analyse the occurrence and host species distribution of campylobacteria species in shorebirds, geese and cattle on grazed coastal meadows in Sweden. METHODS AND RESULTS: Species identification was performed through a polyphasic approach, incorporating Amplified Fragment Length Polymorphism (AFLP) profiling, 16S RNA gene sequence analysis together with extensive phenotypic characterization. From 247 sampled birds and 71 cattle, we retrieved 113 urease positive thermophilic Campylobacter (UPTC) and 16 Campylobacter jejuni ssp. jejuni isolates. Furthermore, 18 isolates of Helicobacter canadensis, and five isolates that potentially represent a new genus of micro-aerophilic, spiral and Gram-negative bacteria were isolated. The distribution of bacterial species on hosts was uneven: all H. canadensis isolates were retrieved from geese, while all but one of the Campylobacter lari UPTC isolates were found in shorebirds. AFLP type distribution of Camp. lari UPTC isolates among individual, resampled and breeding-paired Redshank birds generally indicated a constant shift in strain populations over time and absence of geographical clustering. CONCLUSIONS: The large number of isolated campylobacteria, including species that are zoonotic enteropathogens, indicates that these wild birds potentially may serve as reservoirs of human infections. However, despite a common environment, the different host species largely carried their own campylobacteria populations, indicating that cross-species transmission is rare. SIGNIFICANCE AND IMPACT OF THE STUDY: Our study is one of few that provide data on the occurrence of campylobacteria in wild animals, adding information on the ecology and epidemiology of micro-organisms that are of public health concern.

Campylobacter hyointestinalis subsp. hyointestinalis, a common Campylobacter species in reindeer.

AIMS: To study the prevalence of Campylobacter spp. in the faecal material of reindeer, and to identify the isolates by means of a polyphasic approach. In addition, to study the genetic diversity of Camp. hyointestinalis subsp. hyointestinalis reindeer isolates by pulsed-field gel electrophoresis (PFGE). METHODS AND RESULTS: The material, collected during the slaughter period in autumn 1998, comprised 399 faecal contents from the reindeer (Rangifer tarandus), a semi-domesticated, meat-producing ruminant of northern Finland. These samples came from 16 herds in the areas of eight reindeer slaughterhouses. Samples were cultured by methods suitable for isolation of fastidious Campylobacter species. Of all samples, 6% (24/399) were Campylobacter-positive. Phenotypic characteristics, SDS-PAGE protein patterns, dot blot DNA-DNA hybridization, 23S rDNA restriction fragment polymorphism analysis and PFGE identified the isolates as Camp. hyointestinalis subsp. hyointestinalis. CONCLUSIONS: Campylobacter hyointestinalis subsp. hyointestinalis was the only Campylobacter species isolated from reindeer in this study. The isolates showed high genomic diversity in PFGE with the restriction enzymes SmaI and KpnI. SIGNIFICANCE AND IMPACT OF THE STUDY: PFGE analysis is a useful subtyping method for epidemiological studies. Contaminated reindeer meat can be a source for human infections.