A one-year study of campylobacter carriage by individual Danish broiler chickens as the basis for selection of Campylobacter spp. strains for a chicken infection model (original) (raw)
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Occurrence and genotypes of Campylobacter species in broilers during the rearing period
Avian pathology : journal of the W.V.P.A, 2016
Poultry are the main source of Campylobacter infection worldwide. To obtain information on Campylobacter-infected flocks and create a reference for preventing and controlling Campylobacter at farm level, Campylobacter isolates were recovered from broilers and the environments of nine chicken flocks in two farms during growth. The genetic relationship between the Campylobacter isolates was determined using multilocus sequence typing. Flocks were colonized as early as 3 weeks after introduction to the farm. The highest colonization rate was more than 90% and occurred 4-6 weeks after introduction to the farm. Quantitative data showed that the highest Campylobacter loads appeared at 1-2 weeks after initial colonization. Campylobacter loads in cloacal swabs in four flocks were significantly higher at 5 weeks than at 3 weeks (P < 0.05). Multilocus sequence typing of 171 selected isolates revealed 20 sequence types (STs), which consisted of 12 STs for Campylobacter jejuni and eight for ...
A 1-year epidemiological study of campylobacters in 18 Swedish chicken farms
Preventive Veterinary Medicine, 1996
During processing, Campylobucter may be spread over the carcass. Thus, undercooked chicken meat, or other foods contaminated by raw chicken can act as a source of infection to humans. This study was conducted to identify risk factors for chicken flocks being colonized with Cumpylobacter. Eighteen chicken farms with altogether 62 chicken compartments were studied for 1 year with visits during each growing period and sampling of chicken caecal contents at slaughter. Four to six subsequent flocks were raised in each compartment during the study. A detailed questionnaire was used to record farm parameters such as building materials, feed and water equipment, hygiene and management routines. Cumpylobucter prevalence varied between farms, between growing periods within the farms and also during the year, with lowest prevalence during the spring. Campylobacters were isolated from 27% out of 287 flocks. Only two farms were negative at all samplings. Often the flock following a positive flock in a compartment was negative, indicating that normal cleaning and disinfecting routines are sufficient for eliminating the bacteria from the house. Usually only one serotype was found in each positive flock. Cumpylobacter occurrence increased with the age of the chickens at slaughter, and also with flock size.
Correlations between Campylobacter spp. prevalence in the environment and broiler flocks
Journal of applied microbiology, 2007
To investigate (i) possible correlations between the presence of Campylobacter spp. in the surroundings of broiler farms and their incidence in flocks, and (ii) possible associations between weather conditions and the occurrence of Campylobacter spp. Farms were selected according to previous results from the Swedish Campylobacter programme. Samples were collected in and around broiler houses during the rearing period from 131 flocks on 31 farms, including sock samples from the ground outside, from the floor in the broiler houses and anterooms, and samples from insects, water, feed and ventilation shafts. As expected, there was a difference in Campylobacter isolation rates for different categories of farms regarding samples taken in the houses. However, there were no differences regarding the presence of Campylobacter spp. in the environment between producers that often deliver Campylobacter-positive slaughter batches and those that rarely deliver positive batches. Campylobacter spp....
PLoS ONE, 2011
Campylobacter successfully colonizes broiler chickens, but little is known about the longer term natural history of colonization, since most flocks are slaughtered at an immature age. In this study, the prevalence and genetic diversity of Campylobacter colonizing a single free-range broiler breeder flock was investigated over the course of a year. The age of the flock was the most important factor in determining both the prevalence and diversity of Campylobacter over time. There was no correlation with season, temperature, the amount of rain and sunshine, or the dynamics of colonization amongst geographically and temporally matched broiler flocks. The higher prevalence rates coincided with the age at which broiler chickens are typically slaughtered, but then in the absence of bio-security or other intervention methods, and despite changes in flock management, the prevalence fell to significantly lower levels for the remainder of the study. The genetic diversity of Campylobacter increased as the flock aged, implying that genotypes were accumulated within the flock and may persist for a long time. A better understanding of the ecology of Campylobacter within commercial chicken flocks will allow the design of more effective farm-based interventions.
Quantifying Transmission of Campylobacter spp. among Broilers
Applied and Environmental Microbiology, 2005
Campylobacter species are frequently identified as a cause of human gastroenteritis, often from eating or mishandling contaminated poultry products. Quantitative knowledge of transmission of Campylobacter in broiler flocks is necessary, as this may help to determine the moment of introduction of Campylobacter in broiler flocks more precisely. The aim of this study was to determine the transmission rate parameter in broiler flocks. Four experiments were performed, each with four Campylobacter-inoculated chicks housed with 396 contact chicks per group. Colonization was monitored by regularly testing fecal samples for Campylobacter. A mathematical model was used to quantify the transmission rate, which was determined to be 1.04 new cases per colonized chick per day. This would imply that, for example, in a flock of 20,000 broilers, the prevalence of Campylobacter would increase from 5% to 95% within 6 days after Campylobacter introduction. The model and the estimated transmission rate parameter can be used to develop a suitable sampling scheme to determine transmission in commercial broiler flocks, to estimate whether control measures can reduce the transmission rate, or to estimate when Campylobacter was introduced into a colonized broiler flock on the basis of the time course of transmission in the flock.
International Journal of Food Microbiology, 2008
On 15 Swiss poultry farms, broiler flocks, other farm animals, and the environment were examined during consecutive rearing periods to investigate the occurrence and genetic diversity of Campylobacter. Of the 5154 collected samples, 311 (6%) from 14 farms were Campylobacter positive by culture. Amongst the positive samples, 228 tested positive for Campylobacter jejuni and 92 for Campylobacter coli. Positive samples originated from broilers, the broiler houses, cattle, pigs, bantams, laying hens, a horse, and a mouse. Feed, litter, flies, and the supply air to the broiler house tested negative. By flagellin gene typing (fla-RFLP) and pulsed-field gel electrophoresis (PFGE), 917 Campylobacter isolates were genotyped. Additionally, amplified fragment length polymorphism (AFLP) analysis was performed on 15 assorted strains. On eight farms, matching genotypes were isolated from broiler flocks and other farm animals: Certain genotypes from cattle (farms H, K, L, and M), pigs (farms D and P), or laying hens (farm L) were subsequently found in the broiler flocks, whereas other genotypes initially present in the broiler flocks turned up in cattle (farms A, D, and O). These results emphasize the importance of other farm animals on poultry farms for broiler flock colonization. Indications of persistent contamination of the broiler house were evident on four farms (C, D, I, and L) where matching genotypes were detected in consecutive broiler flocks, but not concurrently in other samples. By fla-RFLP, PFGE, and confirmed by AFLP, some genotypes proofed to be identical across different farms.
Epidemiology and Infection, 2003
During the period January 1998-December 2001, all Danish broiler flocks were monitored bacteriologically for thermophilic campylobacters and isolates were stored at x80 xC. Six neighbouring broiler farms in a small community were selected for detailed examination of all Campylobacter jejuni isolated (n=180) from these farms during 1998-2000 using Penner serotyping and pulsed-field gel electrophoresis (PFGE). The area and the farms were selected according to their prevalence of campylobacter so that both farms with low and high frequencies of campylobacter positive flocks were included in the study. The frequency of campylobacter positive flocks on the six farms ranged from 24 . 5 to 72 . 7%. One hundred and eighty of the isolates were C. jejuni (included in this study), 14 isolates were C. coli whereas 7 isolates belonged to other species but were not further identified. By serotyping of all C. jejuni 56 isolates (31 . 5%) were assigned to the 4-complex, 32 isolates (18 . 0%) to serotype 2, 12 isolates (6 . 7 %) to serotype 11, and 11 isolates (6 . 2%) were assigned to serotype 12. In three farms, 4-complex was the most prevalent serotype, in one farm it was the second most frequently isolated serotype, while serotypes 2 and 1,44, respectively, were the most frequently isolated from the two remaining farms. This serotype distribution differed from the overall country-wide distribution where serotypes 2 and 1,44 are the most prevalent. All serotype 4-complex isolates from the six selected farms were compared by PFGE to serotype 4-complex isolates from the rest of the country. The results showed that there was a high level of diversity among isolates from the whole country, whereas isolates from the six farms were very homogeneous and only displayed one or a few different PFGE patterns on each farm. It is suggested that certain campylobacter clones persist in a confined geographical area, probably at the farm, and that the broiler houses may be repeatedly infected with a few C. jejuni clones during succeeding broiler flocks. New clones may be introduced, however, the sources and vehicles are yet unknown.
Epidemiology and Infection, 2003
During the period January 1998-December 2001, all Danish broiler flocks were monitored bacteriologically for thermophilic campylobacters and isolates were stored at x80 xC. Six neighbouring broiler farms in a small community were selected for detailed examination of all Campylobacter jejuni isolated (n=180) from these farms during 1998-2000 using Penner serotyping and pulsed-field gel electrophoresis (PFGE). The area and the farms were selected according to their prevalence of campylobacter so that both farms with low and high frequencies of campylobacter positive flocks were included in the study. The frequency of campylobacter positive flocks on the six farms ranged from 24. 5 to 72. 7%. One hundred and eighty of the isolates were C. jejuni (included in this study), 14 isolates were C. coli whereas 7 isolates belonged to other species but were not further identified. By serotyping of all C. jejuni 56 isolates (31. 5%) were assigned to the 4-complex, 32 isolates (18. 0%) to serotype 2, 12 isolates (6. 7 %) to serotype 11, and 11 isolates (6. 2%) were assigned to serotype 12. In three farms, 4-complex was the most prevalent serotype, in one farm it was the second most frequently isolated serotype, while serotypes 2 and 1,44, respectively, were the most frequently isolated from the two remaining farms. This serotype distribution differed from the overall country-wide distribution where serotypes 2 and 1,44 are the most prevalent. All serotype 4-complex isolates from the six selected farms were compared by PFGE to serotype 4-complex isolates from the rest of the country. The results showed that there was a high level of diversity among isolates from the whole country, whereas isolates from the six farms were very homogeneous and only displayed one or a few different PFGE patterns on each farm. It is suggested that certain campylobacter clones persist in a confined geographical area, probably at the farm, and that the broiler houses may be repeatedly infected with a few C. jejuni clones during succeeding broiler flocks. New clones may be introduced, however, the sources and vehicles are yet unknown.
Lack of Evidence for Vertical Transmission of Campylobacter spp. in Chickens
Applied and Environmental Microbiology, 2006
Campylobacter jejuni is a major cause of bacterial food-borne infection in the industrial world. There is evidence that C. jejuni is present in eggs and hatchery fluff, opening the possibility for vertical transmission from hens to progeny. Poultry operations in Iceland provide an excellent opportunity to study this possibility, since breeding flocks are established solely from eggs imported from grandparent flocks in Sweden. This leaves limited opportunity for grandparents and their progeny to share isolates through horizontal transmission. While Campylobacter was not detected in all grandparent flocks, 13 of the 16 egg import lots consisted of eggs gathered from one or more Campylobacter-positive grandparent flocks. No evidence of Campylobacter was found by PCR in any of the 10 relevant quarantine hatchery fluff samples examined, and no Campylobacter was isolated from the parent birds through 8 weeks, while they were still in quarantine rearing facilities. After the birds were mov...
Epidemiology of Campylobacter in Poultry
De belangrijkste Campylobacter besmettingsroute voor pluimvee is een horizontale overdracht vanuit de omgeving. Dit proefschrift II Behandeling met quinolonen is niet geschikt om het probleem van Campylobacter besmetting bij pluimvee op te lossen.