Most Campylobacter subtypes from sporadic infections can be found in retail poultry products and food animals

Abstract

The subtypes of Campylobacter isolates from human infections in two Danish counties were compared to isolates from retail food samples and faecal samples from chickens, pigs and cattle. During a 1-year period, 1285 Campylobacter isolates from these sources were typed by two methods: 'Penner' heat-stable serotyping and automated ribotyping (RiboPrinting). C. jejuni was the dominating species, but C. coli was more prevalent among food and chicken isolates (16%) compared to human isolates (4%). In total, 356 different combined sero-ribotypes (subtypes) were found. A large subtype overlap was seen between human isolates and isolates from food (66%), chickens (59%) and cattle (83%). This was verified by PFGE typing of 212 isolates representing selected subtypes. All frequent (n>3) subtypes found in food were also present in humans. Sixty-one per cent of the isolates from domestically acquired infections had subtypes that were also found in food as opposed to 31% of travel-associated infections. The results showed differences in the various Campylobacter populations, e.g. the Danish population as reflected in the domestically acquired infections and the Danish-produced food was more uniform than the isolates originating from outside the country. The study shows that most C. jejuni subtypes found in poultry food samples, broiler chickens, and cattle were represented in the domestically acquired cases, indicating that C. jejuni from these reservoirs are likely sources of human infections in Denmark.

Decreasing Trend of Overlapping Multilocus Sequence Types between Human and Chicken Campylobacter jejuni Isolates over a Decade in Finland

“…Several other studies also have reported a 34 to 60% overlap between serotypes, genotypes, and/or sequence types (STs) of patient and poultry isolates using various typing techniques (20,31,37,42).…”

Genomics-Based Molecular Epidemiology of Campylobacter jejuni Isolates from Feedlot Cattle and from People in Alberta, Canada

“…Poultry sources have not accounted for 100% of human infections, and typing surveys have found human Campylobacter strains that do not exhibit similarity (do not cluster) with poultry strains (7,26,27,32,33). Cattle and human Campylobacter isolates have been found to be similar using a variety of molecular typing methods (5,22,33), and typing studies have suggested that cattle may play a role in the epidemiology of campylobacteriosis (5,26,33). In a study by Nielsen et al, human and cattle C. jejuni isolates were identical based on six molecular typing methods (31).…”

Comparison of Molecular Typing Methods Useful for Detecting Clusters of Campylobacter jejuni and C. coli Isolates through Routine Surveillance

“…The detection of C. jejuni in a ground beef sample was unusual. This isolate was indistinguishable by multiple typing methods from one human isolate and closely related to three additional isolates, strongly suggesting that ground beef is a source of human infection with C. jejuni (8,38), especially in the absence of detection of the same type in chicken or any other source. The data presented in the current study support a growing opinion that cattle contribute significantly in some way to the burden of human disease caused by Campylobacter (26,39).…”