Evidence for a Genetically Stable Strain of Campylobacter jejuni

Abstract

The genetic stability of selected epidemiologically linked strains of Campylobacter jejuni during outbreak situations was investigated by using subtyping techniques. Strains isolated from geographically related chicken flock outbreaks in 1998 and from a human outbreak in 1981 were investigated. There was little similarity in the strains obtained from the different chicken flock outbreaks; however, the strains from each of three chicken outbreaks, including strains isolated from various environments, were identical as determined by fla typing, amplified fragment length polymorphism (AFLP) analysis, and pulsed-field gel electrophoresis, which confirmed the genetic stability of these strains during the short time courses of chicken flock outbreaks. The human outbreak samples were compared with strain 81116, which originated from the same outbreak but has since undergone innumerable laboratory passages. Two main AFLP profiles were recognized from this outbreak, which confirmed the serotyping results obtained at the time of the outbreak. The major type isolated from this outbreak (serotype P6:L6) was exemplified by strain 81116. Despite the long existence of strain 81116 as a laboratory strain, the AFLP profile of this strain was identical to the profiles of all the other historical P6:L6 strains from the outbreak, indicating that the genotype has remained stable for almost 20 years. Interestingly, the AFLP profiles of the P6:L6 group of strains from the human outbreak and the strains from one of the recent chicken outbreaks were also identical. This similarity suggests that some clones of C. jejuni remain genetically stable in completely different environments over long periods of time and considerable geographical distances.

Prevalence of Campylobacter subtypes in pheasants (Phasianus colchicus spp. torquatus) in the Czech Republic

“…C. jejuni is a species with genomic instability that affects flagellin typing (Wassenaar et al 1995) and PFGE (Hanninen et al 1999). On the other hand, many C. jejuni strains have been shown to remain genetically stable (Manning et al, 2001). For these reasons some authors describe common genotypes in groups of animals raised simultaneously on the same farm (Guevremont et al, 2004), others have reported that broiler flocks can be colonized by 1-3 and parent flocks by 2-6 different Campylobacter clones.…”

A DNase Encoded by Integrated Element CJIE1 Inhibits Natural Transformation of Campylobacter jejuni

“…Direct experimental evidence of the occurrence of HGT and the generation of genetic diversity in vivo was obtained from experiments with chickens infected with two C. jejuni strains carrying distinct genetic markers (8). However, genetic typing also indicates that stable lineages of C. jejuni exist and thus that not every strain in the C. jejuni population is able to acquire foreign DNA (20,29,34,48).…”

Genetic Characterization and Antibiotic Resistance of Campylobacter jejuni Isolated from Meats, Water, and Humans in Sweden

“…jejuni is considered a genetically diverse species, but nevertheless a limited number of widespread and persistent clones have been identified (11,(14)(15)(16)20). Identical genotypes are commonly present in flocks raised simultaneously on a farm, and clones have also been shown to be able to persist during successive broiler flock rotations (16,20).…”