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Campylobacter epidemiology

insights from subtyping by pulsed-field gel electrophoresis

Höök, Helena (2005). Campylobacter epidemiology. Diss. (sammanfattning/summary) Uppsala : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae, 1652-6880 ; 2005:89
ISBN 91-576-6988-0
[Doctoral thesis]

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Campylobacter jejuni and Campylobacter coli are frequent worldwide causes of food-borne gastroenteritis. Poultry is regarded as the most important infection source. In temperate countries, a marked seasonal variation of human campylobacteriosis is seen, with most cases occurring during the warmer season. In this PhD project, pulsed-field gel electrophoresis, PFGE, was used to explore the genetic and epidemiological relationships among both campylobacters colonising broilers and campylobacters causing sporadic infection in humans. In a commercial broiler flock, a subsequent addition of genotypes occurred during rearing, with two types found at two weeks of age and six types on the day before slaughter. Two new types were found in the slaughter samples. In two-thirds of the individual birds sampled the day before slaughter, more than one type were found. In two separate studies, Campylobacter isolates from humans infected in Sweden were characterised by PFGE. Although a large variation in distinct restriction patterns was found, most isolates could be sorted into clusters based on pattern similarities. Isolates in some clusters and subclusters were significantly more seasonally concentrated than other isolates. A sequenced strain of C. jejuni, NCTC 11168, was used as a reference strain and molecular size marker for PFGE. Using a Campylobacter strain for this purpose may be advantageous compared with using commercially available molecular markers, as the more sample-like DNA migration patterns facilitate and refine interpretation and analysis. In conclusion, PFGE was found to be a useful tool for investigating Campylobacter epidemiology in both broilers and humans. The results show that multiple genotypes of C. jejuni may be present in a commercial broiler flock during rearing and even in gastrointestinal tracts of individual birds. Both recurring environmental exposure and genetic changes within the population may explain the genotype diversity. Although a large number of genotypes may be found among Campylobacter strains infecting humans, a large proportion of these may be genetically related. It seems that certain Campylobacter genotypes infect humans in the regions studied during a short period of the year, and that these genotypes account for a substantial proportion of the cases during the season (summer and early autumn) with highest campylobacteriosis incidence.

Authors/Creators:Höök, Helena
Title:Campylobacter epidemiology
Subtitle:insights from subtyping by pulsed-field gel electrophoresis
Series Name/Journal:Acta Universitatis Agriculturae Sueciae
Year of publishing :August 2005
Number of Pages:65
ALLI. Höök, H., Abdel Fattah, M., Ericsson, H., Vågsholm, I. & Danielsson-Tham, M.-L. 2005. Genotype dynamics of Campylobacter jejuni in a broiler flock. Veterinary Microbiology 106, 109–117. II. Höök, H, Ericsson, H., Vågsholm, I. & Danielsson-Tham, M.-L. A sequenced Campylobacter jejuni strain as reference and molecular size marker for pulsed-field gel electrophoresis. In manuscript. III. Höök, H., Ekegren, M.-B., Ericsson, H., Vågsholm, I. & Danielsson-Tham, M.-L. 2004. Genetic and epidemiological relationships among Campylobacter isolates from humans. Scandinavian Journal of Infectious Diseases 36, 435–442. IV. Höök, H., Ericsson, H., Gustavsson, O., Vågsholm, I. & Danielsson-Tham, M.-L. Seasonal distribution of Campylobacter genotypes from humans in Sweden. In manuscript.
Place of Publication:Uppsala
ISBN for printed version:91-576-6988-0
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:Q Food science > Q03 Food contamination and toxicology
Subjects:Not in use, please see Agris categories
Agrovoc terms:epidemiology, chickens, poultry, human diseases, foodborne diseases, digestive system diseases, genotypes, campylobacter, electrophoresis
Keywords:campylobacter, campylobacter jejuni, epidemiology, seasons, gastrointestinal diseases, humans, chickens, genotyping, pulsed-field gel electrophoresis
Permanent URL:
ID Code:908
Department:(VH) > Dept. of Biomedical Sciences and Veterinary Public Health
Deposited By: Helena Höök
Deposited On:01 Sep 2005 00:00
Metadata Last Modified:02 Dec 2014 10:08

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