Campylobacter spp. in broiler flocks at farm level and the potential for cross-contamination during slaughter

Screening of broiler flocks for their Campylobacter carriage on farm level and consequently the spread of Campylobacter spp. during slaughtering can help to identify hygiene control points. Therefore, between December 2001 and August 2002 in total 51 broiler flocks from three farms of different geographical regions in Germany were analysed for thermophilic Campylobacter. Campylobacter spp. were isolated from 45% of the broiler flocks examined. Subsequently, 1101 samples were taken from 22 flocks during different stages of processing. Samples were collected from: transport crates before and after cleaning/disinfection, evisceration, post-scalded and post-chilled carcasses and endproducts. Additionally, 45 selected Campylobacter isolates of droppings were genotyped by pulsed-field gel electrophoresis (PFGE). Campylobacter carriage of flocks showed seasonal variation, with the highest contamination rate during the period of June to August. No evidence was found for a horizontal transmission from one broiler flock to the next via a persistent house-contamination. In each positive flock, one to three different genotypes were found. One or two clones dominated isolations obtained from the farm level. The fact that in different flocks indistinguishable isolates of clonal origin were detected during the same rearing period suggested a transmission between the broiler flocks or an intermittent common external source. In one case, isolates of clonal origin were detected in various farms during different rearing periods. Sampling during processing confirmed that the entrance of a positive flock resulted in contamination of the abattoir environment. Campylobacter spp. were isolated from all sampling stages along the processing line, with a percentage of 91.1-100 of isolates at different stages of slaughtering.     

Influence of production system on the rate of onset of Campylobacter colonization in chicken flocks reared extensively in the United Kingdom

1. Because thermophilic Campylobacter spp. are common in chicken flocks reared extensively, cross-sectional and longitudinal studies were carried out on organic and free-range farms to determine the onset of colonisation (lag phase) and likely sources of flock infection. 2. For 14 organic and 14 free range flocks, there was a difference in lag phases, with the former being colonized at a mean of 14·1 d in comparison with 31·6 d for the latter. Whereas most free-range flocks became colonized when released on to pasture, those reared organically were usually colonized at the housed brooding stage. 3. Further study of organic flocks on three farms over 7 successive crop cycles confirmed that colonisation was strongly influenced by the prevailing husbandry conditions and was not a consequence of the length of the rearing period. 4. Molecular epidemiological investigations on a farm showing the shortest lag phase, using PFGE typing with two different restriction enzymes (SmaI and KpnI) and flaA SVR sequence typing, revealed that potential sources of colonisation for organic chickens were already present on the farm at the time of chick placement. Such sources included the ante area of the brooding house, surrounding pasture and other livestock being kept on the farm. 5. Overall, the study demonstrated that, under UK conditions, the prevalence of colonisation was greater in extensive flocks (95-100%) than it was for conventional broilers (55%), similar to the situation in other countries, but all three management systems showed comparable levels of caecal carriage in positive birds (log(10)/g 6·2-6·7).     

Identification of a new source of Campylobacter contamination in poultry: transmission from breeder hens to broiler chickens

Campylobacter jejuni, a foodborne pathogen closely associated with market poultry, is considered to be the most frequent agent of human gastroenteritis in the United States. The pathways involved in the contamination of poultry flocks, vertical transmission and/or horizontal transmission, are unclear. In this study, Campylobacter isolates from two independent commercial broiler breeder flocks, as well as from their respective progeny, were characterized and compared by PstI ribotype analysis and by DNA sequence analysis of the short variable region (SVR) of the flaA gene (flaA SVR). Campylobacter isolates originating from one set of breeder hens and the feces from their respective progeny demonstrated identical ribotype patterns as well as identical flaA SVR DNA sequences, thereby suggesting that these isolates were clonal in origin. Ribotype analysis of Campylobacter isolates from the second set of breeder hens and processed carcasses from their offspring resulted in two patterns. Sequence analysis placed these isolates into two closely related groups and one distant group, similar to the ribotype analysis. These results demonstrate that Campylobacter isolates from commercial broiler breeder flocks and from the respective broiler progeny may be of clonal origin and that breeder hens can serve as a source for Campylobacter contamination in poultry flocks.     

The prevalence and genetic diversity of Campylobacter spp. in domestic 'backyard' poultry in Canterbury, New Zealand

Campylobacteriosis is the most commonly notified illness in New Zealand. Whilst the importance of commercial poultry in campylobacteriosis is well established, little is known about the possible role of chickens kept at home as a direct animal/faecal contact or consumption exposure pathway. The aim of this study was to determine the prevalence and genetic diversity of Campylobacter spp. in domestic backyard chicken flocks in the Canterbury region of New Zealand. Poultry faecal samples were collected from 35 domestic 'backyard' poultry flocks from urban and rural properties around the Canterbury Region of New Zealand. A total of 291 samples were collected and tested for the presence of thermotolerant Campylobacter spp. and positive isolates were analysed using pulsed-field gel electrophoresis (PFGE) using both SmaI and KpnI enzymes. There was a high prevalence of Campylobacter spp. with 86% of flocks testing positive. Campylobacter jejuni alone, Campylobacter coli alone and both C. jejuni and C. coli were detected in 20 (57%), 2 (6%) and 8 (23%) of the flocks respectively. SmaI/KpnI PFGE analysis identified 50 different genotypes across the 35 flocks. Genotype diversity richness was highest on the lifestyle block and farm properties with 43 different genotypes isolated, whilst urban properties displayed the least richness with 12 genotypes isolated. Rural flocks tended to have more different genotypes in a given flock than urban flocks. Comparison of the genotypes with the PulseNet Aotearoa Campylobacter database showed that 28 of the genotypes had previously been isolated from human cases of campylobacteriosis. Many of these were also indistinguishable from Campylobacter spp. previously isolated from retail chicken. Therefore, contact with backyard poultry or their faecal material is a potential additional infection pathway outside of exposure to the established pathways associated with the consumption of Campylobacter-contaminated commercial meat or foods cross-contaminated from contaminated poultry.     

Genotyping Campylobacter jejuni strains isolated from the gut and oviduct of laying hens

Campylobacter jejuni frequently colonizes the avian intestine. Recent evidence suggests that this organism can also colonize the oviduct of laying hens. However, the source and role of this colonization are unknown. Isolates from the ceca, cloacae, and oviducts of 11 laying hens in three intensive egg-producing flocks were genotyped by Fla typing with the restriction fragment length polymorphism of the polymerase chain reaction product of the flaA and flaB genes (fla typing) and pulsed-field gel electrophoresis (PFGE). A diversity in fla types and PFGE types was observed within and between flocks. Individual birds could be colonized by different genotypes at various intestinal and oviduct sites. However, the oviduct of individual birds appeared to be colonized by only one genotype at the time of sampling. In two birds, matching isolates investigated from the intestinal and reproductive tracts were genotypically identical but different from those oviduct isolates found in other birds in the same flock. Interestingly, not all cecal isolates appeared to be equally able to colonize the oviduct. These results suggest that oviduct colonization may result from ascending infection via the cloaca and that some strains of C. jejuni may be better adapted than others to oviduct colonization.     

The carry-over of Campylobacter isolates between sequential poultry flocks

The carry-over of Campylobacter strains from one flock to a subsequent flock in the same broiler house has been studied using molecular epidemiological techniques. In all, 524 Campylobacter strains, isolated from two sequential broiler flocks from 60 broiler houses, were typed by restriction fragment polymorphism of the polymerase chain reaction (PCR) product of the flaA and flaB genes (fla typing). Selected strains were also typed using pulsed field gel electrophoresis (PFGE). By fla typing, 15 (21%) of the 60 houses with Campylobacter-positive sequential flocks had identical genotypes. In 10 (16% overall) of these houses the strains were also identical by PFGE. The difference in PFGE patterns in the strains from the three remaining houses may be indicative of genetic instability. Overall, these results suggest that carry-over from one flock to a subsequent flock in the same house is a relatively infrequent event and, therefore, that routine broiler house cleansing and/or disinfection is largely adequate to eliminate Campylobacter contamination. An alternative explanation of the low level carry-over is a persistent source or reservoir, external to the environment of the broiler houses.     

Phenotypic and genotypic characterization of Salmonella arizonae from an integrated turkey operation

Fifty cases submitted between 2000 and 2002 were selected for retrospective analysis to evaluate possible relationships between Salmonella arizonae isolated from breeder flocks, hatching eggs, and meat bird flocks belonging to a single turkey integrator. In all the meat bird cases selected for this study, arizonosis was the primary diagnosis. In birds under 1 month of age, clinical signs and pathologic changes were observed in older birds. The Salmonella arizonae isolates were analyzed by antibiotic resistance pattern and serotype and genotyped by pulsed-field gel electrophoresis (PFGE). Serotyping and PFGE yielded similar results, but the antibiotic resistance patterns did not correspond to either serotyping or PFGE typing. The presence of common pulsed-field patterns in breeder flocks, eggs, and meat bird flocks suggested that S. arizonae was being transmitted vertically from the breeder flock.     

Dynamics of Campylobacter spp. spread investigated in 14 broiler flocks in Switzerland

Ten conventional and four extensive outdoor broiler flocks, distributed over nine farms, were investigated twice per week during a 35-58-day rearing period to observe the dynamics of Campylobacter spp. spread within these flocks. Strains isolated during this period were genotyped by restriction fragment length polymorphism analysis of the flaA gene and macrorestriction profiling with pulsed field gel electrophoresis. A total of 4112 samples were collected; 157 (3.8%) of these samples were Campylobacter positive, with all C. jejuni. The positive samples were distributed over three conventional and two extensive outdoor flocks on five farms. These five positive flocks were colonized from the fifth to the seventh week of age and remained colonized until slaughter. Each of the flocks showed a flock-specific genotype of Campylobacter that predominated until slaughter. Presuming different ways of entry, a combination of this fact and the observed dynamics of C. jejuni spread within the flocks indicates that a single source from the environment may have been responsible for the colonization of each flock. These conclusions may serve to further develop combat strategies at farm level.     

A longitudinal study of Campylobacter distribution in a turkey production chain

Background

Campylobacter is the most common cause of bacterial enteritis worldwide. Handling and eating of contaminated poultry meat has considered as one of the risk factors for human campylobacteriosis.Campylobacter contamination can occur at all stages of a poultry production cycle. The objective of this study was to determine the occurrence of Campylobacter during a complete turkey production cycle which lasts for 1,5 years of time. For detection of Campylobacter, a conventional culture method was compared with a PCR method. Campylobacter isolates from different types of samples have been identified to the species level by a multiplex PCR assay.

Methods

Samples (N = 456) were regularly collected from one turkey parent flock, the hatchery, six different commercial turkey farms and from 11 different stages at the slaughterhouse. For the detection of Campylobacter, a conventional culture and a PCR method were used. Campylobacter isolates (n = 143) were identified to species level by a multiplex PCR assay.

Results

No Campylobacter were detected in either the samples from the turkey parent flock or from hatchery samples using the culture method. PCR detected Campylobacter DNA in five faecal samples and one fluff and eggshell sample. Six flocks out of 12 commercial turkey flocks where found negative at the farm level but only two were negative at the slaughterhouse.

Conclusion

During the brooding period Campylobacter might have contact with the birds without spreading of the contamination within the flock. Contamination of working surfaces and equipment during slaughter of a Campylobacter positive turkey flock can persist and lead to possible contamination of negative flocks even after the end of the day''s cleaning and desinfection. Reduction of contamination at farm by a high level of biosecurity control and hygiene may be one of the most efficient ways to reduce the amount of contaminated poultry meat in Finland. Due to the low numbers of Campylobacter in the Finnish turkey production chain, enrichment PCR seems to be the optimal detection method here.     

Transmission of Campylobacter spp. in a poultry slaughterhouse and genetic characterisation of the isolates by pulsed-field gel electrophoresis

1. Contamination of retail products with Campylobacter spp. during the slaughter of poultry is a well-known problem of product hygiene. Mechanical evisceration often leads to intestinal rupture and discharge of gut contents, which can contain zoonotic and human pathogens. Processes along the slaughter line cause aerosols and airborne droplets, containing bacterial loads. 2. To estimate the possible transmission routes of intestinal Campylobacter, 36 measurements of the bioaerosol (Andersen sampler and SKC BioSampler), 30 cloacal (of three flocks), 10 equipment and 4 sedimentation samples were tested for the presence of Campylobacter species. 3. The results imply that, in addition to contaminated equipment, which was Campylobacter-positive in 80% of cases, aerosols with peak values of 4.0 x 10(4) (test series 1) and 1.4 x 10(4) (test series 2) CFU/m3 also provide a potential vector for horizontal transmission. 4. To explore the genetic similarities of isolates from different origins, 18 isolates recovered from air, 26 cloacal, 8 equipment and 4 sedimentation isolates were analysed by pulsed-field gel electrophoresis (PFGE), using the restriction enzymes Sma I and Sal I. The similarity of cloacal isolates with isolates from equipment, air and sediment, suggest that the contamination is of intestinal origin. 5. There were direct links between Campylobacter-positive flocks and the presence of the same strains in the aerosol of the slaughter hall. Air as a potential source for microbial transmission must be taken into account.     

Occurrence of virulence genes among Campylobacter jejuni and Campylobacter coli isolates from domestic animals and children

The presence of the flaA, cadF, cdtB and iam genes of Campylobacter spp. was determined with the PCR method. The materials to investigate were 56 C. jejuni and 23 C. coli strains isolated from clinical samples (children and domestic animals). It was found that all of the Campylobacter spp. isolates from children with diarrhoea and domestic animals had cadF gene, responsible for adherence. The flaA gene was present in all Campylobacter spp. isolates derived from children and cats. Occurrence of flaA gene was confirmed in 100% of C. jejuni strains obtained from dogs. The high prevalence of the cdtB gene associated with toxin production was observed in this study (100%-Campylobacter spp. isolates obtained from dogs and cats, 97.9%-Campylobacter spp. isolates from children). The isolates showed a wide variation for the presence of iam gene. The lowest prevalence (23.5%) was detected in Campylobacter spp. obtained from dogs. The highest rates of iam detection (91.6%) were revealed in C. coli isolates from children.     

Genotype analyses of Campylobacter isolated from the gastrointestinal tracts and the reproductive tracts of broiler breeder roosters

Campylobacter is considered to be the leading bacterial etiologic agent of acute gastroenteritis in humans. Evidence implicates poultry as a major source of the organism for human illness; however, the pathways involved in Campylobacter contamination of poultry flocks, horizontal transmission and/or vertical transmission, remain unclear. Recent evidence implicates breeders as a potential source for Campylobacter contamination of the subsequent broiler offspring. In this investigation, Campylobacter isolated from feces, cloacal swabs, ceca, semen, and vas deferens of 12 breeder broiler roosters were genotyped by both flagellin A short variable region (flaA SVR) DNA sequence analysis and repetitive element (rep)-polymerase chain reaction (PCR). In 9 of 12 roosters, Campylobacter was isolated from multiple sites sampled. Comparison of multiple isolates obtained from individual roosters revealed variable results. In five of the nine roosters, all Campylobacter isolated demonstrated closely related flaA SVR DNA sequences as well as rep-PCR patterns; isolates from these roosters were collected from both the gastrointestinal and the reproductive tracts or from the gastrointestinal tract alone. The remaining four roosters had Campylobacter that were distinct by both typing methods. Isolates from two of these four roosters originated from both the gastrointestinal and the reproductive tracts. Isolates from the remaining two roosters originated from only the reproductive tract. Comparisons of all Campylobacter isolates recovered from a distinct sample type within either the reproductive tract or the gastrointestinal tract (feces, semen, cloaca, vas deferens, or ceca) were quite diverse. No relationship between the genotypes and the sample type could be ascertained. Further investigation is needed to determine the route of contamination and if the presence of Campylobacter within the rooster leads to contamination of the broiler offspring via the fertilized egg.     

Relationship of Campylobacter isolated from poultry and from darkling beetles in New Zealand

Campylobacter, a foodborne pathogen closely associated with poultry, is considered to be an important agent of human gastroenteritis in New Zealand. The pathways involved in the contamination of poultry flocks remain unclear; however, many vectors, such as insects, rodents, and wild birds, have been implicated. Infestation of poultry houses by insects, particularly darkling beetles (Alphitobius diaperinus), is difficult to control. Furthermore, darkling beetles are known vectors for a variety of pathogens that include Salmonella, infectious bursal disease virus, Aspergillus, Escherichia coli, and Marek's disease virus. In this investigation, the relationship between darkling beetles and Campylobacter contamination of poultry flocks was investigated. A New Zealand breeder flock and four of its progeny broiler flocks were included in the study. Samples of beetles and of intestinal excreta of the birds were cultured for the presence of Campylobacter spp. A subset of the recovered isolates was subsequently genotyped using flaA short variable region (SVR) DNA sequence analysis. A large number of Campylobacter subtypes were isolated, indicating that Campylobacter colonization of poultry is likely to arise from a number of different reservoirs. However, a set of genetically distinct isolates were found to be common to the broiler flocks and to the beetles. This research provides data that indicates that Alphitobius diaperinus may serve as a source of Campylobacter contamination of poultry. A more thorough understanding of the relationship between beetle infestation and the Campylobacter status of poultry flocks should enable progress in further development of biosecurity control measures.     

Drug use and antimicrobial resistance among Escherichia coli and Enterococcus spp. isolates from chicken and turkey flocks slaughtered in Quebec,Canada

An observational study was conducted of chicken and turkey flocks slaughtered at federal processing plants in the province of Quebec, Canada. The objectives were to estimate prevalence of drug use at hatchery and on farm and to identify antimicrobial resistance (AMR) in cecal Escherichia coli and Enterococcus spp. isolates and factors associated with AMR. Eighty-two chicken flocks and 59 turkey flocks were sampled. At the hatchery, the most used antimicrobial was ceftiofur in chickens (76% of flocks) and spectinomycin in turkeys (42% of flocks). Virginiamycin was the antimicrobial most frequently added to the feed in both chicken and turkey flocks. At least 1 E. coli isolate resistant to third-generation cephalosporins was present in all chicken flocks and in a third of turkey flocks. Resistance to tetracycline, streptomycin, and sulfisoxazole was detected in > 90% of flocks for E. coli isolates. Antimicrobial resistance (AMR) was observed to bacitracin, erythromycin, lincomycin, quinupristin-dalfopristin, and tetracycline in both chicken and turkey flocks for Enterococcus spp. isolates. No resistance to vancomycin was observed. The use of ceftiofur at hatchery was significantly associated with the proportion of ceftiofur-resistant E. coli isolates in chicken flocks. In turkey flocks, ceftiofur resistance was more frequent when turkeys were placed on litter previously used by chickens. Associations between drug use and resistance were observed with tetracycline (turkey) in E. coli isolates and with bacitracin (chicken and turkey), gentamicin (turkey), and tylosin (chicken) in Enterococcus spp. isolates. Further studies are needed to provide producers and veterinarians with alternative management practices and tools in order to reduce the use of antimicrobial feed additives in poultry.     

Distribution and genetic characterization of porcine Campylobacter coli isolates

The aim of this study was to evaluate the impact of the slaughter process on the Campylobacter (C.) coli prevalence on pig carcasses and finally pork. To detect C. spp., faecal samples, organ samples and surfaces of slaughter pigs were sampled. Additionally, various abattoir surfaces (n=208) and 227 pork and minced meat samples were included in our study.Whereas a high C. spp. prevalence (64.0%) was detectable in the faeces of slaughter pigs (all isolates were identified as C. coli), low detection rates were observed on pig carcasses after the slaughter process before the chilling period (21.1%).The impact of chilling reduced the detection rate of C spp. on pig carcasses even further to 0.8%. Only C. jejuni strains were isolated after the chilling process. Chilling and the associated drying of the skin are responsible for that massive reduction of C. spp prevalence. Significantly more C. spp. were isolated from livers compared to the corresponding carcasses. Only 5 out of 208 swab samples from different surfaces of the abattoir were C. coli positive. Bacteriological investigation could not detect any C. spp. strains from pork and minced pork meat.The low detection rates at the end of the slaughter and processing line indicate that pork may only play a minor role in the transmission of C. coli infections to humans. By genotyping C. coli-isolates from selected animals we were able to demonstrate three possible ways of contamination of the slaughter carcass surface. Genetically highly related strains were detectable on carcass surfaces of consecutively slaughtered animals. Faecal isolates and isolates from the carcass surface showed occasional high similarities. C. coli-genotypes from tonsils and genotypes from the corresponding slaughter carcasses formed a close cluster.     

Serotype and genotype diversity and hatchery transmission of Campylobacter jejuni in commercial poultry flocks.

We investigated the genotype and serotype diversity of Campylobacter coli and C. jejuni in two parent flocks of adult hens and their offspring over two rotations in order to evaluate the role of hatchery mediated transmission and/or vertical transmission of campylobacters in broiler flocks. In total, 314 C. jejuni and 32 C. coli isolates from parent and broiler flocks and from the surroundings of broiler houses were typed by flagellin gene PCR/RFLP (fla-typing), and selected isolates were also typed by serotyping and macrorestriction profiling using PFGE (MRP/PFGE). The combined typing results showed that the broiler flocks could be colonised by 1-3 different Campylobacter clones and parent flocks could be colonised by 2-6 different clones. C. coli was isolated from up to 36% of birds in one parent flock, whereas only C. jejuni was isolated from broiler flocks. C. jejuni clones from different flocks were clearly discriminated by fla-typing as well as by MRP/PFGE, except for a few cases where individual isolates belonging to two different clones were found to have altered fla-types. Similarly, one C. coli clone showed pronounced fla-type variation. The present results lead to the conclusion that vertical transmission or horizontal transmission via the hatchery are not significant transmission routes of C. jejuni to broiler chickens under Danish conditions. In the cases where more than one Campylobacter clone simultaneously colonised flocks, we found that the different clones coexisted in flocks rather than excluding each other.     

PFGE and PCR/RFLP typing of Campylobacter jejuni strains from poultry

1. Pulsed-field gel electrophoresis (PFGE) and PCR-restriction fragment length polymorphisms of the flagellin gene (fla-RFLP) were used to analyse 92 poultry and 110 human strains of Campylobacter jejuni. 2. Among poultry strains, 11 fla-RFLP and 11 PFGE subtypes were found, while human strains could be divided into 23 fla-RFLP and 32 PFGE subtypes. Altogether, 31 fla-RFLP and 32 PFGE subtypes were found. 3. The results show that individual flocks in farms are mostly infected with a single C. jejuni clone, while during subsequent colonisation their genotypes altered. fla-RFLP and PFGE profiles in poultry and humans were identical in less than 6% of cases. The results found so far confirm previous findings that chicken meat does not represent as important a source of campylobacteriosis as was previously believed. 4. The typing of Campylobacter sp. forms the basis for an evaluation of the current state and risk assessment of various Campylobacter sp. sources in relation to humans. Examination of samples with only one method is insufficient for epidemiology studies, because apparently different clones identified with one method could originate from a single clone, which could be proved with the other method.     

Dynamics of populations of Campylobacter jejuni in two grandparent broiler breeder farms: persistent vs. transient strains

The objectives of the study were to characterize and investigate the populations of Campylobacter jejuni in two grandparent broiler breeder farms over four years. Caecal as well as farm environmental samples were obtained. Campylobacter isolates were characterized by macrorestriction profile (SmaI and KpnI-PFGE) and PCR-RFLP of the flaA gene. Susceptibility tests against seven antimicrobials were also performed. Birds were negative for Campylobacter spp. when they came to these two production farms (20 weeks), and most of the flocks remained uncolonized until they were 23 weeks old. Eighteen genotypes were characterized, with one of them (genotype 2) appearing and persisting over the study period in the two farms. In general, the strains exhibited high genetic stability, and most of them could be seen as transient in the farms, being substituted by other strains when their flock was substituted. Only one environmental sampling was positive for C. jejuni. Two different genotypes were characterized; one of them was isolated from the birds of that farm two years before. The susceptibility data point to the idea of an environmental source or reservoir of this genotype. Regarding the susceptibility of the populations, as other studies have shown, quinolone resistance (alone or combined with other resistances) was the most frequent: 68.5%. Quinolone- and multidrug-resistant strains are a matter of concern in public health. In conclusion, this survey shows the complexity of the study of the colonization of farms by C. jejuni.     

Multiple typing for the epidemiological study of contamination of broilers with thermotolerant Campylobacter

This study aims to investigate the genetic diversity of thermotolerant Campylobacter in commercial broiler flocks and in the environment of broiler farms in Belgium. Seven out of 18 investigated flocks became colonized during rearing. Fluorescent amplified fragment length polymorphism (FAFLP), pulsed field gel electrophoresis (PFGE), restriction fragment length polymorphism of the flagellin A gene (flaA-RFLP) and antimicrobial resistance profile (ARP) were used for typing of the isolates. By the combination of FAFLP and PFGE, 22 Campylobacter genotypes could be distinguished. Colonization was almost exclusively with Campylobacter jejuni and unique genotypes were found in each flock. Multiple genotypes were detected in the broilers of 3 flocks, either simultaneously or successively. In 5 flocks, strains that were resistant to at least one antibiotic (mostly tetracycline) were found. The presence of other broiler houses on the farm did not result in a higher probability of colonization. The nipple water was contaminated with the same genotype as the broilers, illustrating its importance for transmission of Campylobacter. The same genotype was detected in a water puddle and in the broiler flock during rearing in 3 flocks. Once, the same genotype was isolated from the ditch water shortly before it was detected in the broilers.