The transmission of campylobacter in piggeries; an epidemiological study

The campylobacter infection of 10 sows and their piglets was monitored. These pigs werekept on two multiplier farms. Rectal faeces samples were taken from the sows shortly beforelittering and at different intervals after littering. Swab samples of rectal content were taken fromsix piglets per sow at different intervals after birth. Nine sows were shown to be infected withcampylobacter before litter and all sows after litter, with an average colony count of 4·1in log N g^–1 of faeces. Half of the piglets became infected withcampylobacter during the first week of life and 85%, after four weeks. Two genetic subtypingmethods (ERIC-PCR and RFLP) were used to study the relationships between campylobacterisolates from sows and piglets. A large diversity of campylobacter subtypes was found.Nevertheless, piglets and their mothers often harboured campylobacter isolates with identicalgenetic subtyping profiles, suggesting that piglets become infected via their mothers. However,observed similarities in genetic subtyping profiles between campylobacters isolated on differentfarms made this difficult to prove.     

Establishing a campylobacter-free pig population through a top-down approach

Fattening pigs are often infected with campylobacter. To eliminate campylobacter from the pig population, a top-down approach, involving the breeding and reproduction farms, seems appropriate. In order to investigate the effectiveness of a top-down approach, sows' faeces from the following farms were analysed for the presence of campylobacter: one specific pathogen free (SPF) farm, three top-breeding farms with no connection with SPF breeding, and a breeding farm repopulated with SPF sows after a period of vacancy (farm 5). The faeces samples from the SPF farm were free from campylobacter. The three top-breeding farms provided faeces samples which were 98% positive for campylobacter. However, only 22% of the faeces samples from farm 5 were positive for campylobacter. In a period of 20 months, the percentage of sows infected with campylobacter on farm 5 did not significantly increase. Genetic typing with ERIC-PCR and RFLP of campylobacter isolates from one of the top-breeding farms and from farm 5 showed a high diversity of campylobacter types. The results suggest that a campylobacter-free pig population can be established in breeding farms by combining a top-down approach (campylobacter-free top-breeding farms) with a strict regime of hygiene management.     

Metabolic fingerprinting and fermentative capacity of the intestinal flora of pigs during pre- and post-weaning periods

We used the Phene Plate generalized microplates to investigate the metabolic activities of faecal flora of pigs during pre- and post-weaning periods. Weekly samples were collected from four sows and their litters (four piglets from each) during 5 months. The metabolic fingerprints obtained from faecal floras of sows and their litters in the first sampling occasion was very similar, suggesting that sows were the initial source of flora for piglets. This similarity, however, was lost in week 2 and piglets developed new types of flora which, although similar among the litter-mates, differed from those of the sows. The metabolic fingerprints of pigs' floras during the post-weaning period also differed from those of the suckling period. On day 70 pigs were transferred to a fattening stable. The faecal flora of the animals during this period was unstable in each individual and differed among litter-mates. A pattern of successive changes was observed in the fermentative capacity (FC) of pigs' floras reaching the highest value before weaning (day 34). An overall decrease in the FC value of faecal floras was observed as a consequence of dietary shifts from milk to solid food to high energy fattening diet. The mean FC value of pig floras on the first sampling occasion (mean ± S.D. = 0·41 ± 0·02) was significantly higher than that obtained in the last sampling occasion (day 145) (0·31 ± 0·04) ( P < 0·001). Faecal floras of sows also had lower FC values (0·25 ± 0·01) than those of piglets suggesting that loss of FC by the faecal flora of young pigs will continue as they age.     

Sources of Campylobacter spp. colonizing housed broiler flocks during rearing

The study aimed to identify sources of campylobacter in 10 housed broiler flocks from three United Kingdom poultry companies. Samples from (i) the breeder flocks, which supplied the broilers, (ii) cleaned and disinfected houses prior to chick placement, (iii) the chickens, and (iv) the environments inside and outside the broiler houses during rearing were examined. Samples were collected at frequent intervals and examined for Campylobacter spp. Characterization of the isolates using multilocus sequence typing (MLST), serotyping, phage typing, and flaA restriction fragment length polymorphism typing was performed. Seven flocks became colonized during the growing period. Campylobacter spp. were detected in the environment surrounding the broiler house, prior to as well as during flock colonization, for six of these flocks. On two occasions, isolates detected in a puddle just prior to the birds being placed were indistinguishable from those colonizing the birds. Once flocks were colonized, indistinguishable strains of campylobacter were found in the feed and water and in the air of the broiler house. Campylobacter spp. were also detected in the air up to 30 m downstream of the broiler house, which raises the issue of the role of airborne transmission in the spread of campylobacter. At any time during rearing, broiler flocks were colonized by only one or two types determined by MLST but these changed, with some strains superseding others. In conclusion, the study provided strong evidence for the environment as a source of campylobacters colonizing housed broiler flocks. It also demonstrated colonization by successive campylobacter types determined by MLST during the life of a flock.     

Improved method for the isolation of Campylobacter jejuni and Campylobacter coli bacteriophages

A centrifugation and filtration method of isolating Campylobacter phages has been developed. Forty-nine Campylobacter phages were isolated from 272 effluent samples of which 42 produced lysis with Campylobacter jejuni strains and seven with C. coli strains. Phages were recovered from pig manure, abattoir effluents, human faeces, sewage and poultry manure. Phages were not isolated from water samples, cattle and sheep faeces or farm pasture soil.     

Phenotypic characterization of intestinal Escherichia coli of pigs during suckling, postweaning, and fattening periods.

A highly discriminatory and standardized biochemical fingerprinting method was used to monitor the persistence and colonization of intestinal Escherichia coli isolated from the feces of four sows and their litters (four piglets from each) during the suckling, postweaning, and fattening periods. Altogether, 195 fecal samples were collected and 1,827 E. coli strains were tested (mean number of isolates tested per fecal sample per pig, 9.5). Strains were divided into similarity groups on the basis of their biochemical phenotypes (BPTs). The diversity of E. coli strains in each sample was measured with Simpson's index of diversity, and similarity between E. coli floras of piglets was calculated with a population similarity index. Each fecal sample contained several BPTs of E. coli, some of which dominated that population. The intestinal colonization of piglets consisted of successive waves of different E. coli BPTs, the tenure of which varied from a few days to 2 weeks. Most of these BPTs disappeared in the succeeding samples and were not recovered again from the same piglets. On the other hand, some E. coli strains which colonized piglets early during the suckling period persisted for a long period and were referred to as resident BPTs. Each piglet carried more than one resident BPT (mean of 2.4 BPTs per pig), some of which were also found in other piglets.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparative digestibility of energy and nutrients in diets fed to sows and growing pigs

The objective of this research was to compare values for digestible energy (DE) and metabolisable energy (ME) and apparent total tract digestibility (ATTD) of nutrients in 11 diets fed to both growing pigs and gestating sows. Three diets were based on corn, wheat or sorghum and eight diets were based on a combination of corn and soybean meal, canola meal, conventional distillers’ dried grains with solubles, low-fat distillers’ dried grains with solubles, corn germ meal, corn bran, wheat middlings or soybean hulls. A total of 88 gestating sows (252 ± 24.2 kg BW; parity two to six) and 88 growing barrows (40 ± 4.7 kg BW) were used and randomly allotted to the 11 diets with eight replicate sows or pigs per diet. Faecal and urine samples were collected for 4 d following a 19 d adaptation period. The DE, ME and ATTD of gross energy (GE), acid detergent fibre (ADF), neutral detergent fibre (NDF) and crude protein (CP) in the 11 diets were calculated. Gestating sows had greater (p < 0.05) ATTD of GE and CP and DE values for all diets compared with growing pigs. Gestating sows also had greater (p < 0.05) ME values than growing pigs for the three grain diets and the diets containing wheat middlings and soybean hulls. No differences were observed in ATTD of ADF and NDF between gestating sows and growing pigs for any of the diets, except that gestating sows had greater (p < 0.05) ATTD of NDF than growing pigs when they were fed the four protein diets. The ATTD of GE and CP and DE values in gestating sows may be predicted by using equations generated from the values of ATTD of GE and CP and DE values obtained in growing pigs. Results of this research indicate that ATTD values of CP and GE obtained in gestating sows are greater than the values obtained in growing pigs, but values for ATTD of ADF obtained in growing pigs are not different from values in gestating sows.     

The heterogeneity of Campylobacter jejuni and Campylobacter coli strains isolated from healthy cattle

AIMS: To identify campylobacters isolated from clinically healthy cattle at species level by a multiplex polymerase chain reaction (m-PCR). The heterogeneity among Campylobacter jejuni and Campylobacter coli isolates was also investigated by using a restriction fragment length polymorphism (RFLP) analysis of flagellin (flaA) gene. METHODS AND RESULTS: Samples of intestinal contents, gall bladders, liver and faeces were collected from a total number of 1154 healthy cattle. The samples were inoculated onto Preston enrichment broth and agar. Of 1154 samples, 301 (26.1%) were positive for Campylobacter spp. Using an m-PCR assay for species identification, 179 (59.5%) were positive with C. jejuni specific primers while 30 (10%) were positive with C. coli specific primers. None of the liver samples examined was positive for C. jejuni or C. coli by mPCR. All the isolates identified as C. jejuni and C. coli were successfully subtyped by flaA typing. Of the 209 isolates tested, 28 different flaA types were found. Twenty-three flaA types were identified among 179 C. jejuni isolates and the remaining five from C. coli isolates. CONCLUSIONS: Although the overall results suggest that the degree of heterogeneity among the flaA genes of thermophilic Campylobacter strains isolated from healthy cattle is relatively high, they should be treated cautiously as the number of band types for C. coli was low and band type 8 in C. jejuni was represented by a high percentage (%58). SIGNIFICANCE AND IMPACT OF THE STUDY: The findings of the present study suggest that healthy cattle can play role in the contamination of environment and human food chain by Campylobacter spp.     

A genotyping investigation of the colonization of piglets by Campylobacter coli in the first 10 weeks of life

Aims:  To examine the Campylobacter genotypes colonizing a litter of piglets during the first 10 weeks of life and compare them with those of the sow.
Methods and Results:  Campylobacters were isolated by direct plating of anal swabs. Piglets ( n  = 6) were sampled six times and five isolates per piglet obtained each time. The sow was also sampled but 20 isolates per sampling obtained. Isolates were genotyped by random amplification of polymorphic DNA, pulsed field gel electrophoresis and polymerase chain reaction/restriction fragment length polymorphism of the flagellin gene.
Initially piglets were colonized by Campylobacter coli genotypes from the mother but after 66 days 33% of piglet isolates (based on a mean of the three-genotyping methods) were from other sources. The sow died after 14 days and the initial Campylobacter flora of the foster sow was subsequently replaced by genotypes from the piglets mother. However these constituted only a minor part of her flora after 52 days. Both foster sow and piglets carried multiple genotypes of Camp. coli : up to four in a single piglet sample and seven in one from the sow.
Significance and Impact of the Study:  Piglets are initially colonized by Camp. coli genotypes from their mother but later other genotypes displace them. Colonization is dynamic with the sow able to acquire genotypes from the piglets.
Conclusions:  The large numbers of Camp. coli genotypes carried by pigs, and frequent successions of dominant types, will render epidemiological studies problematic.     

Comparison of 23S polymerase chain reaction-restriction fragment length polymorphism and amplified fragment length polymorphism techniques as typing systems for thermophilic campylobacters

In this study, we evaluated the combination of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and amplified fragment length polymorphism (AFLP) molecular typing techniques for the analysis of thermophilic campylobacter species isolated from clinical and poultry samples. 23S PCR-RFLP analysis performed to fingerprint 69 strains exhibited an excellent level of typability. Eleven different types were defined at 100% linkage level following numerical analysis of band patterns. Differentiation of Campylobacter jejuni and Campylobacter coli at species level was achieved although no significant relationship could be observed between the profiles and the origin of the strains. Simplified AFLP analysis of the isolates disclosed the presence of 66 different banding patterns. The resulting dendrogram showed a high diversity among the strains studied. All the isolates were grouped within eight main types with a 69% homology degree among them. Differentiation at subspecies level was possible but no significant relationship could be observed between the AFLP profiles and the origin of the strains. When used in combination, 23S PCR-RFLP and single-enzyme AFLP methods can be applied to determine taxonomic and epidemiological relationships among thermophilic campylobacters.     

Fly larvicidal activity in the faeces of cattle and pigs treated with endectocide products

Bioassays were conducted to study the effect of a single therapeutic dose of injectable ivermectin, doramectin or moxidectin given to cattle and pigs and excreted in their faeces, against larvae of the housefly, Musca domestica L. (Diptera: Muscidae). Five cattle were treated with each of the test products. Cattle faecal samples were collected before treatment and on days 1, 2, 3, 6, 10, 16, 20, 23 and 28 after treatment. Three groups of pigs, each comprising 12-14 pregnant sows and gilts, were used in the experiment. Pig faeces was collected from each group before treatment and on days 1, 3, 5, 7, 9, 11, 13, 15 and 20 after treatment. Thirty, first-stage larvae were placed into 100 g of faeces. Five replicates were examined for each time-point and for each endectocide group. Evaluation was based on the number of larvae surviving to adult emergence. Low numbers of adults emerged from samples taken from cattle 1 day after treatment, indicating that ivermectin and doramectin were rapidly excreted in the faeces and affected the development of the house fly. A larvicidal effect of both drugs in cattle faeces was present for a period of about 3-4 weeks and lasted a few days longer in cattle treated with doramectin than with ivermectin. In cattle, the larvicidal activity of moxidectin was first observed in faecal samples collected 2 days post-treatment; however, it killed fewer larvae than the other two drugs. The larvicidal effect of moxidectin subsequently decreased. Ivermectin and doramectin exhibited a pronounced larvicidal effect against the house fly in the faeces of pigs. The effect of doramectin was of longer duration. Moxidectin gave the weakest larvicidal effect in pig faeces. The main difference between the results obtained for the two livestock species is that peak toxicity occurred relatively later and for a shorter duration in pig than in cattle faeces.     

Transformation of Trichothecenes in Ileal Digesta and Faeces from Pigs

The capacity of pig gastrointestinal microflora to metabolise the trichothecenes 3-acetyl-deoxynivalenol (3-acDON) and nivalenol (NIV) was investigated. 3-acDON was deacetylated to DON in anaerobic incubations with pig faeces collected at different pig farms. Furthermore, both 3-acDON and NIV were metabolised to the corresponding de-epoxy metabolite in these incubates. Five pigs, in which the gastrointestinal microflora lacked the ability to transform 3-acDON and NIV to their corresponding de-epoxidated metabolites, were given low levels of DON in the feed for seven weeks. The gastrointestinal micro-organisms did not acquire the de-epoxidation ability during the seven week long exposure period. At the end of the exposure period, faeces from pigs with a known de-epoxidation ability was spread out in the pens and left for 24 hours. One week after the faeces had been spread out in the pens, the de-epoxidation ability was found in faecal incubations from four out of five experimental pigs. This change in metabolic ability of the intestinal de-epoxidation ability was not accompanied by any detectable changes in the DNA-profiles of the bacterial community composition. The results show that the intestinal de-epoxidation ability is common at pig farms in the Uppsala area, and that the ability may be transferred between pigs in a stock.     

Arcobacter population dynamics in pigs on farrow-to-finish farms

Healthy pigs are an important reservoir for the emerging human pathogen Arcobacter which can result in contamination of porcine carcasses and pork and the spread of arcobacters into the environment. Up to now, the excretion of arcobacters by pigs has been studied, but information about the transmission routes in fattening pigs is lacking. The present study aimed to elucidate the Arcobacter population dynamics in pigs during the fattening period on four farrow-to-finish farms. On each farm, 30 clinically healthy, 12-week-old piglets were selected. Fecal samples were collected on 10 sampling occasions until a slaughter age of 30 weeks was reached. Arcobacter spp. were isolated by a selective method and identified by multiplex PCR. The genetic diversity was examined by amplified fragment length polymorphism and enterobacterial repetitive intergenic consensus PCR. The Arcobacter presence in the fecal samples on the four farms ranged from 11.3 to 50.0%, with excretion levels of up to 10(4) CFU/g feces. The ratio in which Arcobacter species were isolated varied between the farms and over time. Characterization revealed a high degree of genotypic diversity among the isolates. Arcobacter strains persisted and spread within the finishing unit during the fattening period. The occurrence of both unique and shared genotypes in pigs in adjacent and nonadjacent pens demonstrates that transmission routes other than fecal-oral transmission occur.     

High prevalence of Yersinia enterocolitica 4:O3 on pig offal in southern Germany: a slaughtering technique problem

Prevalence and contamination routes of pathogenic Yersinia enterocolitica were studied in Southern Germany. Tonsil and faeces samples of 50 fattening pigs, 140 offal samples and 120 minced meat samples were examined. Pig and offal samples were collected from a slaughterhouse approved by the European Union, and minced meat samples from two large meat factories. Yersinia enterocolitica was isolated using direct plating, overnight enrichment and selective enrichment in MRB and ITC broth. The isolates were bio- and serotyped, and pathogenicity was studied using two plasmid-encoded virulence markers: calcium dependence and Congo red absorption. The genotypes were studied with pulsed-field gel electrophoresis using NotI enzyme. Prevalence of pathogenic Y. enterocolitica 4:O3 was 60% and 10% in tonsils and faeces of fattening pigs, respectively. Besides tonsils, prevalence of pathogenic Y. enterocolitica 4:O3 was also high in other pluck set samples, including tongues, lungs, hearts, diaphragms and livers. However, the highest isolation rate was obtained from the tonsils. Kidneys, which were not attached to the pluck set and did not hang together with tonsils on the rack, had the lowest isolation rate. Yersinia enterocolitica 4:O3 was isolated from 12% of minced meat samples. A total of 25 NotI profiles were obtained from porcine samples. The most common genotype, NBI, found in tonsils was also the most common type recovered from offal and minced meat samples. The high contamination rate of tonsils, and the indistinguishable NotI profiles obtained from tonsils and offal indicate that the tonsils contaminate offal when they are removed and hung on the rack together. When the head, with the tonsils and tongue, is not removed prior to evisceration and is not handled and inspected separately, it is difficult to control the spread of Y. enterocolitica 4:O3 from tonsils to the carcass, and subsequently, to meat.     

Identification of Campylobacter infection in chickens from volatile faecal emissions.

Volatile organic compounds from chicken faeces were investigated as biomarkers for Campylobacter infection. Campylobacter are major poultry-borne zoonotic pathogens, colonizing the avian intestinal tract. Chicken faeces are the principal source of contamination of carcasses. Fresh faeces were collected on farm sites, and Campylobacter status established microbiologically. Volatile organic compounds were pre-concentrated from the headspace above 71 separate faecal samples using solid-phase microextraction and separated and identified by gas chromatography/mass spectrometry. A Campylobacter-specific profile was identified using six of the extracted volatile organic compounds. The model developed reliably identified the presence or absence of Campylobacter in >95% of chickens. The volatile biomarker identification approach for assessing avian infection is a novel approach to enhancing biosecurity in the poultry industry and should reduce the risk of disease transmission to humans.     

Longitudinal study of the persistence of antimicrobial-resistant campylobacter strains in distinct Swine production systems on farms, at slaughter, and in the environment

The objectives of this study were to compare and characterize the prevalence of antimicrobial-resistant (AR) Campylobacter in conventional and antimicrobial-free (ABF) production systems on farms, at slaughter, and in the environment. Fecal and environmental samples were collected from ABF farms (pigs, 1,239; environment, 797) and conventional farms (pigs, 1,650; environment, 1,325). At slaughter, we collected samples from carcasses, including postevisceration swabs, postchill swabs, and mesenteric lymph nodes from ABF systems (postevisceration swabs, 182; postchill swabs, 199; mesenteric lymph nodes, 184) and conventional systems (postevisceration swabs, 272; postchill swabs, 271; mesenteric lymph nodes, 255) at separate processing facilities. We also sampled the processing plant environment, including truck and lairage floor swab samples (ABF, 115; conventional, 90). Overall, a total of 2,908 Campylobacter isolates, including Campylobacter coli (farm, 2,557, 99.8%; slaughter, 341, 98.3%) and Campylobacter jejuni (farm, 4, 0.2%; slaughter, 6, 1.7%), were isolated in the study. There was no significant difference in the prevalence of Campylobacter between ABF and conventionally raised pigs (farrowing, P = 0.20; nursery, P = 0.06; finishing, P = 0.24) and the environment (P = 0.37). At slaughter, Campylobacter was isolated from all of the stages, including postchill. The highest frequencies of resistance were exhibited against tetracycline (ABF, 48.2%; conventional, 88.3%). Ciprofloxacin-resistant C. coli isolates were observed in conventionally raised (17.1%) and ABF (1.2%) pigs (P = 0.11). Antimicrobial use data from conventional farms indicated significant associations between oxytetracycline use and tetracycline resistance in the nursery pigs (P = 0.01), between tiamulin exposure and azithromycin and erythromycin resistance in nursery (P < 0.01) and finishing (P < 0.01) pigs, and between enrofloxacin exposure and ciprofloxacin and nalidixic acid resistance in farrowing (P < 0.01) and nursery (P < 0.01) pigs. Identical antimicrobial resistance profiles were observed in the pigs and their environments on farms and at slaughter. In summary, our results highlight the persistence and dissemination of AR Campylobacter from farm to slaughter in ABF and conventionally raised pigs and their environments.     

Survey and comparison of major intestinal flora in captive and wild ring-tailed lemur (Lemur catta) populations

A survey to identify the major intestinal species of aerobic bacteria, protozoa and helminths was conducted on captive and wild populations of ring-tailed lemurs (Lemur catta). Samples were collected from 50 captive lemurs at 11 zoological institutions in the United States. In Madagascar, 98 aerobic bacteria samples and 99 parasite samples were collected from eight sites chosen to cover a variety of populations across the species range. Identical collection, preservation and lab techniques were used for captive and wild populations. The predominant types of aerobic bacteria flora were identified via five separate tests. The tests for parasites conducted included flotation, sedimentation and FA/GC. Twenty-seven bacteria unique to either the captive or wild populations were cultured with eight of these being statistically significantly different. Fourteen bacteria common to both populations were cultured, of which six differed significantly. Entamoeba coli was the only parasite common to both the captive and wild populations. Giardia spp., Isospora spp., strongyles-type ova, Entamoeba spp. and Entamoeba polecki were found only in captive samples. Cryptosporidium, Balantidium coli, pinworm-type ova, and two fluke-like ova were seen only in wild samples. In addition, samples were compared for both bacteria and parasites from three unique field sites in Madagascar. In this three-site comparison, six types of bacteria were statistically significantly different. No significant differences regarding parasites were seen. Significant differences were found between the captive and wild populations, whereas fewer differences were found between sites within Madagascar. Although we isolated Campylobacter and Giardia, all animals appeared clinically healthy.     

Multilocus sequence typing performed on Campylobacter coli isolates from humans, broilers, pigs and cattle originating in Denmark

AIMS: To assess whether Campylobacter coli isolated from different sources in Denmark constitute separate populations. METHODS AND RESULTS: Multilocus sequence typing (MLST) was applied to 160 C. coli isolates from animal origin, food products and human cases of gastroenteritis. The isolates were collected in Denmark over a 2-year period. In total, 84 sequence types (STs) were obtained and 57 of these STs were novel to this study. Ten per cent of the isolates possessed STs that were found in both human, poultry and pig isolates. Only 10% of the isolates from pigs shared ST with isolates from humans, and these shared STs were found in poultry isolates as well. CONCLUSIONS: Great genetic diversity was seen within the Danish C. coli population. Furthermore, we found that the C. coli types isolated from Danish pigs constitute a small fraction of the C. coli causing human disease. SIGNIFICANCE AND IMPACT OF THE STUDY: C. coli isolates from pigs is presumably not a significant source of human campylobacteriosis in Denmark. The Danish C. coli isolates include 68% STs novel to this study, showing a great diversity compared with studies from other countries.     

A survey of Campylobacter species shed in faeces of beef cattle using polymerase chain reaction

A polymerase chain reaction (PCR)-based survey of campylobacters associated with faeces collected from 382 beef cattle was undertaken. To ensure the removal of PCR inhibitors present in faeces and determine if adequate extraction was achieved, faeces were seeded with internal control DNA (i.e., DNA designed to amplify with the Campylobacter genus primer set, but provide a smaller amplicon) before the extraction procedure. In only two samples (0.5%) were the internal control or Campylobacter genus amplicons not detected. In the remaining 380 faecal samples, Campylobacter DNA was detected in 83% of the faecal samples (80% of the faecal samples were positive for Campylobacter genus DNA, and 3% of the samples were negative for Campylobacter genus DNA but positive for DNA of individual species). The most frequently detected species was Campylobacter lanienae (49%), a species only recently connected to livestock hosts. Campylobacter jejuni DNA was detected in 38% of the faecal samples, and Campylobacter hyointestinalis and Campylobacter coli DNA were detected in 8% and 0.5% of the samples, respectively. Campylobacter fetus DNA was not detected. Twenty-four percent of the faecal samples contained DNA of at least two species of Campylobacter. Of these samples, the majority (81%) contained DNA of C. jejuni and C. lanienae. The results of this study indicate that beef cattle commonly release a variety of Campylobacter species into the environment and may contribute to the high prevalence of campylobacteriosis in humans inhabiting areas of intensive cattle production, such as southern Alberta. Furthermore, this study demonstrates the utility of using PCR as a rapid and accurate method for simultaneously detecting the DNA of a diverse number of Campylobacter species associated with bovine faeces.     

Isolation, growth on prebiotics and probiotic potential of novel bifidobacteria from pigs

Bifidobacteria were isolated from the faeces of pigs of various ages and examined for their potential use as probiotics in combination with di- and oligosaccharides. Ninty-six per cent of the isolates were found to have characteristics in common with Bifidobacterium boum, B. thermophilum and B. choerinum. B. thermophilum was most commonly isolated from sows, whereas most of the other strains were isolated from piglets. A few strains of each species were able to grow in the presence of air. A microplate assay was modified to allow comparison of growth on different substrates. Di- and oligosaccharides considered to promote bifidobacteria were screened for their ability to support growth of selected isolates in vitro. Growth on these substrates varied within and between species. Of the fructose oligosaccharides tested, Actilight P supported the best growth of the widest range of strains. The strains which grew best on the disaccharide lactulose were related to B. choerinum and some of these strains grew on xylo-oligosaccharides. It seems that prebiotic di- and oligosaccharides may have both a species and intra-species/strain selective effect. B. choerinum appeared to be well adapted to the gut of pre-weaned piglets.