Submitted to: Poultry Science
Publication Type: Abstract Only
Publication Acceptance Date: 3/26/2008
Publication Date: 7/20/2008
Citation: Richardson, L.J., Cox Jr, N.A., Buhr, R.J., Hiett, K.L., Akins, E.D., Harrison, M.A. 2008. Molecular phylogeny of the flaA short variable region and invasiveness among campylobacter spp. isolated from the blood and ceca of commerical broilers. Poultry Science. 87:(Supp.1)MP321. p. 102.
Interpretive Summary: Campylobacter spp. are a major cause of human bacterial gastroenteritis in the U.S. and poultry products have been implemented as a significant infection source. In order for better intervention strategies to be implemented pre-harvest, an increased understanding of Campylobacter spp. ecology in poultry flocks and within birds has to be attained. The aim of the current study was to determine whether Campylobacter spp. are in circulating blood of commercial broilers and evaluate the genetic relatedness and invasiveness of those isolates. C. jejuni was recovered from the circulating blood of market age commercial broilers and different subtypes of C. jejuni were recovered. Certain C. jejuni isolates that were in the blood were more invasive than those isolates from the ceca of the same bird. The significance is that C. jejuni recovery from the circulating blood provides insight into a possible means of rapid dissemination to tissues and suggests that Campylobacter spp. are not strictly limited to the lumens of the digestive tracts.
Technical Abstract: Campylobacter spp. are present in the internal organs and tissues of broilers but the dissemination route is unknown. The purpose of the study was to determine whether Campylobacter spp. are in circulating blood of commercial broilers and evaluate the genetic relatedness and invasiveness of those isolates. Broilers were acquired from three U.S. commercial poultry companies. Aseptic techniques were used for blood collection by insertion of a sterile needle into exposed or unexposed brachial veins. Genotyping of the isolates was performed using the flagellinA short variable region (flaA-SVR) DNA sequence analysis. A gentamicin resistant assay was conducted for invasiveness evaluation of the isolates into polarized Caco-2 cells. Overall, Campylobacter jejuni was recovered from 12% of the blood and 46% of the ceca sampled. A total of 7 subtypes by flaA-SVR DNA sequencing were found within 9 flocks. The predominant subtype (flaA-SVR type 1) contained isolates recovered from three flocks and from all three poultry companies. Closely related subtypes of Campylobacter jejuni were naturally present among flocks and poultry companies. Two blood isolates were found to be highly invasive, one showed medium invasiveness, six marginal invasiveness, and 13 no invasiveness. The cecal isolate was noninvasive, while the blood isolate highly invasive in two birds, but similar by flaA SVR DNA sequencing. Campylobacter jejuni recovery from the circulating blood provides insight into a possible means of rapid dissemination to tissues and suggests that Campylobacter spp. are not strictly limited to the lumens of the digestive tracts.