Identification of host-associated alleles by multilocus sequence typing of Campylobacter coli strains from food animals.
Campylobacter coli is a food-borne pathogen associated increasingly with human gastroenteritis. C. coli has a high prevalence in swine, but is isolated also from cattle and poultry. Multilocus sequence typing (MLST) systems have been developed to differentiate C. coli strains. Although substantial allelic diversity was identified across all seven C. coli MLST loci, no correlations were made in two previous studies between allele or sequence type (ST) and the source of the organism. However, this may be due to either the relatively small number or the low diversity of C. coli strains used to validate both MLST studies. This study describes the typing of 488 C. coli strains from 4 different food animal sources (cattle, chickens, swine and turkeys), collected at different times over a 6 year period from different USA geographical locations. A total of 149 STs were identified. The 185 swine strains were the most diverse, possessing 82 STs. The cattle strains were the most clonal; 52/63 (83 %) strains possessed a single ST (ST-1068). A subpopulation of C. coli strains, collected primarily from turkeys, was identified, containing both C. coli- and Campylobacter jejuni-associated MLST alleles, specifically the C. jejuni allele aspA103. The majority of STs and alleles were host associated, i.e. found primarily in strains from a single food-animal source. Only 12/149 (8 %) STs were found in multiple sources. Additionally, the majority (34/46, 74 %) of major (n>5) alleles were more prevalent in certain hosts (swine, poultry). The presence of host-associated C. coli MLST alleles could lead potentially to more efficient source tracking in this species, especially in the trace-back of both sporadic and outbreak human clinical C. coli strains to animal sources.
Miller
William G
WG
Produce Safety and Microbiology Research Unit, Agricultural Research Service, US Department of Agriculture, Albany, CA 94710, USA.
Englen
Mark D
MD
Bacterial Epidemiology and Antimicrobial Resistance Research Unit, Agricultural Research Service, US Department of Agriculture, Russell Research Center, Athens, GA 30605, USA.
Kathariou
Sophia
S
Department of Food Science, North Carolina State University, Raleigh, NC 27695, USA.
Wesley
Irene V
IV
Agricultural Research Service, US Department of Agriculture, National Animal Disease Center, Ames, IA 50010, USA.
Wang
Guilin
G
Produce Safety and Microbiology Research Unit, Agricultural Research Service, US Department of Agriculture, Albany, CA 94710, USA.
Pittenger-Alley
Lauren
L
Bacterial Epidemiology and Antimicrobial Resistance Research Unit, Agricultural Research Service, US Department of Agriculture, Russell Research Center, Athens, GA 30605, USA.
Siletz
Robin M
RM
Department of Food Science, North Carolina State University, Raleigh, NC 27695, USA.
Muraoka
Wayne
W
Agricultural Research Service, US Department of Agriculture, National Animal Disease Center, Ames, IA 50010, USA.
Fedorka-Cray
Paula J
PJ
Bacterial Epidemiology and Antimicrobial Resistance Research Unit, Agricultural Research Service, US Department of Agriculture, Russell Research Center, Athens, GA 30605, USA.
Mandrell
Robert E
RE
Produce Safety and Microbiology Research Unit, Agricultural Research Service, US Department of Agriculture, Albany, CA 94710, USA.
D000483:Alleles; D000818:Animals; D015373:Bacterial Typing Techniques; D017000:Campylobacter coli / Q000145:classification / Q000235:genetics*; D002417:Cattle; D002645:Chickens; D004269:DNA, Bacterial / Q000235:genetics*; D005516:Food Microbiology; D011200:Poultry / Q000382:microbiology*; D017421:Sequence Analysis; D012697:Serine Endopeptidases / Q000235:genetics; D013045:Species Specificity; D013552:Swine; D014422:Turkeys
D004269:DNA, Bacterial; D012697:Serine Endopeptidases