Purpose: The objective of this work is to describe using the comparative genomic fingerprinting (CGF) with 40-gene assay (CGF40) the C. jejuni population circulating in the poultry production chain in France and in different animal reservoirs to determine a link with human cases.
Methods: A total of 645 poultry isolates representative of the French poultry industry (farm, slaughterhouse and retail), 455 isolates from dogs and cats, 122 isolates collected from river water and shells and 143 strains from human campylobacteriosis were typed by CGF40 according to Taboada et al. (2012). Isolates were categorized into types based on more than 90% CGF40 fingerprint similarity (CGF-90%). The results were analyzed using Bionumerics software and the genetic diversity of the different strain populations was evaluated using the Simpson Index of Similarity (ID).
Results: A great diversity has been observed with 141 different types among the 1364 isolates typed (ID=0.958). Within the pet isolates (ID=0.895) and the clinical isolates (ID=0.910), the genetic diversity was significantly lower than among poultry isolates (ID=0.961) and water isolates (ID=0.961). The main part of human isolates (57%) were divided into 4 CGF-90% types all found in chicken and pet isolates. Moreover, few human isolates belong to CGF-90% types sharing by water isolates.
Significance: This is the first large scale survey in France involving representative number of isolates from poultry, pets, river water, shells and humans. The results confirm that poultry meat production remain a substantial source of human infections in France. But other animal reservoirs sources, especially pets, could be potential sources of campylobacteriosis.