Molecular Epidemiology of Campylobacter jejuni Populations in Dairy Cattle, Wildlife, and the Environment in a Farmland Area

Department of Medical Microbiology, School of Medicine, University of Manchester, Clinical Sciences Building, Manchester Royal Infirmary, Manchester M13 9WL, United Kingdom.
Applied and Environmental Microbiology (Impact Factor: 3.67). 07/2008; 74(16):5130-8. DOI: 10.1128/AEM.02198-07
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ABSTRACT We describe a cross-sectional study of the molecular epidemiology of Campylobacter jejuni in a dairy farmland environment, with the aim of elucidating the dynamics of horizontal transmission of C. jejuni genotypes among sources in the area. A collection of 327 C. jejuni isolates from cattle, wildlife, and environmental sources in a 100-km(2) area of farmland in northwest England was characterized by multilocus sequence typing. A total of 91 sequence types and 18 clonal complexes were identified. Clonal complexes ST-21, ST-45, and ST-61, which have been frequently associated with human disease, were the most commonly recovered genotypes in this study. In addition, widely distributed genotypes as well as potentially host-associated genotypes have been identified, which suggests that both restricted and interconnecting pathways of transmission may be operating in the dairy farmland environment. In particular, the ST-61 complex and the ST-21 complex were significantly associated with cattle. In contrast, complex strains ST-45, ST-952, and ST-677 were isolated predominantly from wild birds, wild rabbits, and environmental water. A considerable number of novel sequence types have also been identified, which were unassigned to existing clonal complexes and were frequently isolated from wildlife and environmental sources. The segregated distribution of genotypes among samples from different sources suggests that their transmission to humans is perhaps via independent routes. Insight into the dynamics and interactions of C. jejuni populations between important animal reservoirs and their surrounding environment would improve the identification of sources of Campylobacter infection and the design of control strategies.

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Available from: Mathew Upton, Sep 29, 2015
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    • "Several methods are available to perform molecular epidemiological studies and to carry out source attribution (Foley et al., 2009). Among these, multilocus sequence typing (MLST) has been used successfully to identify the link between C. jejuni isolated from different sources and human C. jejuni infection (Colles et al., 2003; Dingle et al., 2001; Kwan et al., 2008). "
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    ABSTRACT: The study aimed to investigate the prevalence of Campylobacter jejuni in not regularly monitored potential contamination sources such as free-living urban pigeons and crows, dogs, cats and urban environmental water and to assess the possible impact on the epidemiology of campylobacteriosis in children using Multilocus sequence typing (MLST). Campylobacter spp. were detected in 36.2% of faecal samples of free-living urban birds and in 40.4% of environmental water samples. A low prevalence of Campylobacter spp. was detected in dogs and cats, with 7.9% and 9.1%, respectively. Further identification of isolates revealed that environmental water and pet samples were mostly contaminated by other Campylobacter species than C. jejuni, whereas C. jejuni was the most prevalent species in faecal samples of free-living birds (35.4%). This species was the dominant cause of campylobacteriosis in children (91.5%). Apart from that, the diversity of C. jejuni MLST types in free-living birds and children was investigated. Clonal complex (CC) CC179 was predominant among free-living urban birds, however only two children isolates were assigned to this CC. One dog and one children isolate were assigned to the same clonal complex (CC48) and sequence type (ST) ST-918. The dominant two clonal complexes among children clinical isolates (CC353 and CC21) were not detected among C. jejuni strains isolated from environmental sources examined in this study. Since only two CCs were shared by environmental and children C. jejuni isolates and a high number of novel alleles and STs were found in C. jejuni isolated from free-living urban birds and environmental water, there is probably only a very limited link between urban environmental sources and campylobacteriosis in children, particularly in rather cold climatic conditions.
    Journal of Medical Microbiology 07/2014; 63(9):1205-13. DOI:10.1099/jmm.0.072892-0 · 2.25 Impact Factor
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    • "The bacterium readily colonizes a wide variety of animals asymptomatically (e.g. wildlife and livestock), and these animals may serve as a reservoir of infectious cells to humans [3,7,8]. Although C. jejuni is not considered to be a normal constituent of the intestinal microbiota of humans, a large number of asymptomatic humans were positive for the bacterium in developing countries [9]. "
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    ABSTRACT: Campylobacter jejuni causes enterocolitis in humans, but does not incite disease in asymptomatic carrier animals. To survive in the intestine, C. jejuni must successfully compete with the microbiota and overcome the host immune defense. Campylobacter jejuni colonization success varies considerably amongst individual mice, and we examined the degree to which the intestinal microbiota was affected in mice (i.e. a model carrier animal) colonized by C. jejuni at high relative to low densities. Mice were inoculated with C. jejuni or buffer, and pathogen shedding and intestinal colonization were measured. Histopathologic scoring and quantification of mRNA expression for α-defensins, toll-like receptors, and cytokine genes were conducted. Mucosa-associated bacterial communities were characterized by two approaches: multiplexed barcoded pyrosequencing and terminal restriction fragment length polymorphism analysis. Two C. jejuni treatments were established based on the degree of cecal and colonic colonization; C. jejuni Group A animals were colonized at high cell densities, and C. jejuni Group B animals were colonized at lower cell densities. Histological examination of cecal and colonic tissues indicated that C. jejuni did not incite visible pathologic changes. Although there was no significant difference among treatments in expression of mRNA for α-defensins, toll-like receptors, or cytokine genes, a trend for increased expression of toll-like receptors and cytokine genes was observed for C. jejuni Group A. The results of the two methods to characterize bacterial communities indicated that the composition of the cecal microbiota of C. jejuni Group A mice differed significantly from C. jejuni Group B and Control mice. This difference was due to a reduction in load, diversity and richness of bacteria associated with the cecal mucosa of C. jejuni Group A mice. High density colonization by C. jejuni is associated with a dysbiosis in the cecal microbiota independent of prominent inflammation.
    PLoS ONE 09/2013; 8(9):e75325. DOI:10.1371/journal.pone.0075325 · 3.23 Impact Factor
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    • "Recent studies using MLST have indicated that Campylobacter populations vary between host species and environmental niches (McCarthy et al. 2007) and that their lineages are associated with different host sources (Colles et al. 2003, 2008; Fearnhead et al. 2005; Miller et al. 2006). Further, the occurrence of rare allelic profiles, and their distribution among animal sources, has been reported in previous investigations using MLST (Kwan et al. 2008; Carter et al. 2009). Campylobacter spp. "
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    ABSTRACT: A repeated cross-sectional study was conducted to determine the prevalence of Campylobacter spp. and the population structure of C. jejuni in European starlings and ducks cohabiting multiple public access sites in an urban area of New Zealand. The country's geographical isolation and relatively recent history of introduction of wild bird species, including the European starling and mallard duck, create an ideal setting to explore the impact of geographical separation on the population biology of C. jejuni, as well as potential public health implications. A total of 716 starling and 720 duck fecal samples were collected and screened for C. jejuni over a 12 month period. This study combined molecular genotyping, population genetics and epidemiological modeling and revealed: (i) higher Campylobacter spp. isolation in starlings (46%) compared with ducks (30%), but similar isolation of C. jejuni in ducks (23%) and starlings (21%), (ii) significant associations between the isolation of Campylobacter spp. and host species, sampling location and time of year using logistic regression, (iii) evidence of population differentiation, as indicated by FST, and host-genotype association with clonal complexes CC ST-177 and CC ST-682 associated with starlings, and clonal complexes CC ST-1034, CC ST-692, and CC ST-1332 associated with ducks, and (iv) greater genetic diversity and genotype richness in ducks compared with starlings. These findings provide evidence that host-associated genotypes, such as the starling-associated ST-177 and ST-682, represent lineages that were introduced with the host species in the 19th century. The isolation of sequence types associated with human disease in New Zealand indicate that wild ducks and starlings need to be considered as a potential public health risk, particularly in urban areas. © 2013 The Authors. Microbiology Open published by John Wiley & Sons Ltd.
    MicrobiologyOpen 08/2013; 2(4). DOI:10.1002/mbo3.102 · 2.21 Impact Factor
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