The excretion of campylobacter by eight individually housed fattening pigs was monitored during 15 weeks. Rectal faeces samples were collected six times from these pigs and twice from their mothers (seven sows). Campylobacter was cultured from these samples on Preston medium. In some pigs, samples positive for campylobacter alternated with negative samples. Campylobacter was detected in at least four of the six samples collected per fattening pig. The average campylobacter count per sampling showed a decreasing trend (P < 0·001). of the seven sows, six were shown to excrete campylobacter. Campylobacter isolates of pigs and sows were typed using the Enterobacterial Repetitive Intergenic Consensus Polymerase Chain Reaction (ERIC‐PCR); 28 different campylobacter types were distinguished. Up to five different types were isolated from single faeces samples. Individual porkers could harbour up to eight types during their fattening period. The three types most frequently isolated from the fattening pigs were also present in the sows.

Fourier transform infrared spectroscopy (FT-IR) has been used together with pattern recognition methodology to study isolates belonging to the species Campylobacter coli and Campylobacter jejuni and to compare FT-IR typing schemes with established genomic profiles based on enterobacterial repetitive intergenic consensus PCR (ERIC-PCR). Seventeen isolates were cultivated under standardized conditions for 2, 3, and 4 days to study variability and improve reproducibility. ERIC-PCR profiles and FT-IR spectra were obtained from strains belonging to the species Campylobacter coli and C. jejuni, normalized, and explored by hierarchical clustering and stepwise discriminant analysis. Strains could be differentiated by using mainly the firstderivative FT-IR spectral range, 1,200 to 900 cm ؊1 (described as the carbohydrate region). The reproducibility index varied depending on the ages of the cultures and on the spectral ranges investigated. Classification obtained by FT-IR spectroscopy provided valuable taxonomic information and was mostly in agreement with data from the genotypic method, ERIC-PCR. The classification functions obtained from the discriminant analysis allowed the identification of 98.72% of isolates from the validation set. FT-IR can serve as a valuable tool in the classification, identification, and typing of thermophilic Campylobacter isolates, and a number of types can be differentiated by means of FT-IR spectroscopy.

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.

A S . 2000. Fattening pigs are often infected with campylobacter. To eliminate campylobacter from the pig population, a topdown 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 speci®c 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 signi®cantly increase. Genetic typing with ERIC-PCR and RFLP of campylobacter isolates from one of the topbreeding 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.

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