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One hundred and five bulls from an artificial insemination unit were tested for the presence of Campylobacter fetus subspecies venerealis. The method involved the inoculation of preputial samples into a new transport enrichment medium prior to culture and immunofluorescence tests. Seventeen bulls (16%) were found to be either positive or suspected carriers of C. fetus at one or more sampling times. The average age of these 17 bulls was about two years greater than the average age of all the bulls in the unit. A combined treatment of vaccination and dihydrostreptomycin sulfate injection suppressed or eliminated the organism from carrier bulls. The use of transport enrichment medium has increased our capability and effectiveness to monitor the presence of C. fetus in artificial insemination bulls.

Fluorescent conjugates were prepared from the sera of calves immunized with four Vibrio fetus strains and one Vibrio bubulus strain. The fluorescent antibody technique (FAT) was then used to detect vibrio organisms in preputial fluid collected from 67 bulls belonging to a Canadian artificial insemination (AI) unit. The V. fetus conjugates reacted with both V. fetus var venerealis and V. fetus var intestinalis. V. fetus was found in 20 animals (29.9%), 13 of which also harboured V. bubulus. In two cases, the FAT failed to detect V. fetus which was isolated by concurrent bacteriological examinations. It was concluded that the FAT can be a rapid method of detecting some carrier bulls but more reliable results are obtained when a combination of FAT and bacteriological methods is employed. It was found that a single sample giving negative results is inconclusive and additional tests are required before making a final diagnosis. The FAT can also be used to differentiate V. fetus isolates from V. bubulus.

Preputial fluid samples were collected from 90 bulls in two Ontario artificial insemination units using a penial glove swab technique previously developed by one of us for use in donor bulls. No Campylobacter fetus organisms were identified from the prepuce or from samples of semen collected at the same time from these bulls. The distal genitalia of 200 bulls were collected at a slaughter house. One isolation of a Campylobacter fetus subspecies venerealis was obtained on a culture from the fornix area of the prepuce of one of these bulls.

The enrichment feature of a selective serum-based transport medium for Campylobacter fetus was quantitatively examined. Preputial samples from artificial insemination bulls were spiked with known numbers of C fetus strains and inoculated into transport-enrichment medium (TEM). The survival and multiplication of these strains in TEM under different incubation periods and temperatures were assessed by plate counts. Mean enrichment values of 3.72 log and 4.42 log were observed after incubation at 37 degrees C for two and four days, respectively. There was no significant difference in the enrichment values between the C fetus subspecies venerealis strains and a C fetus subspecies fetus strain. Incubation of inoculated TEM vials at room temperature for up to two days neither improved the growth of C fetus nor affected its subsequent enrichment when the vials were reincubated at 37 degrees C. Comparison of the survival of C fetus with and without the use of TEM under simulated transport conditions demonstrated the superiority of TEM.

A total of 525 specimens from 100 slaughter beef cattle were examined for the presence of Campylobacter jejuni and Campylobacter coli by direct plating and enrichment techniques. Isolates were identified by cultural, biochemical, antibiotic sensitivity, and immunofluorescence tests and further characterized with the aid of recently developed biotyping and serotyping methods. Fifty animals were positive for C. jejuni; only one was positive for C. coli. The distribution pattern of C. jejuni-positive animals, in decreasing order, was steers (55%), bulls (40%), heifers (40%), and cows (22%). Significantly higher isolation rates were obtained from the gall bladders (33%), large intestines (35%), and small intestines (31%) than from the livers (12%) or the lymph nodes (1.4%). C. jejuni isolation by the enrichment technique was 40.2% more frequent than by direct plating; 24-h enrichment resulted in 24% more isolations than 48-h enrichment. Eighty-four of 105 C. jejuni cultures were typable serologically and represented 13 serogroups. Biotype I accounted for 71% of biotyped cultures. Serogroup 7 biotype I was the most commonly encountered (24%) isolate. About one in three positive animals had C. jejuni strains representing more than one serogroup. C. jejuni serogroups encountered in slaughter cattle were similar to those commonly isolated from human sources.