The causative agent of bgc is Campylobacter (C.) fetus subspecies venerealis (enzootic abortion), a bacterium with a distinct tropism for the genital tract of cattle. Infection caused by this pathogen is notifiable. The preputial sack of clinically healthy bulls is the natural reservoir. From which have to be separated infections with C. fetus subspecies fetus. These bacteria have its natural location in the intestinal tract of cattle, but it can also cause abortion (sporadic abortion). The spread of the disease in cattle is mainly due to natural mating. Bulls usually show no signs of disease. As mentioned the semen of clinically healthy bulls can contain the pathogen in that way the risk of spread of this disease is possible by artificial insemination. In female animals, small inflammatory changes in the vaginal and uterine area can be observed. The main symptoms are infertility, abortion in each time of pregnancy and infertility.
After the first infection in the stock, the disease is acute with a sudden drop in conception rate (sometimes below 10%). Over time, the disease enters into a chronic stage, the older animals maturing of its original fertility.
The differences in the epidemiology and clinical significance of both C. fetus subspecies require accurate identification and differentiation. If abortion occurs the differential diagnosis of brucellosis, trichomoniasis and salmonellosis has to be exclude.
Determination of the pathogen
It has developed a working manual for the diagnosis of bovine genital campylobacter-iosis, the recently updated (July 2010) and was published by the FLI. Currently, the traditional distinction between the two subspecies based on a single phenotypic response (tolerance of 1% glycine).
However, glycine tolerant C. fetus subspecies venerealis variants (referred to as biovar intermedius) have been described. In addition, glycine sensitive C. fetus subspecies fetus isolates observed. Now it appears possible, the differentiation of the two C. fetus subspecies by PCR this is the most methodical progress of recent years undoubtedly.
This test is carried out in our lab. The primers were designated by Hum et al. (1997). Using the primers MG3F and MG4R the PCR resulted in a 764-bp amplicon for both subspecies of C. fetus. The differentiation of both subspecies is done by the primer pair VenSF and VenSR, only for C. fetus subspecies venerealis a 142-bp amplicon is obtained.
The type strains of the two subspecies are used as positive controls, nonspecific reactions were not observed. We continue to hold the traditional phenotypic characterization of C. fetus subspecies is essential to see, but in the PCR a valuable tool to complement and confirm these findings.
- Bovine Genital Campylobacteriosis. In: Manual of diagnostic tests and vaccines for terrestrial animals, edition 2010, Volume II, p. 661-670, OIE
Vibrionenseuche der Rinder. In: Amtliche Methodensammlung zur Labordiagnostik von anzeigepflichtigen Tierseuchen, aktualisierte Fassung, Stand: Juli 2010, S. 423-432, Hrsg.: FLI, www.fli.bund.de
- Hum, S., Quinn, K., Brunner, J., On, S.L.W. (1997): Evaluation of a PCR assay for identification and differentiation of Campylobacter fetus subspecies. Aust. Vet. J. 75, 827-831.
- Müller, W., Hotzel, H., Schulze, F. (2003): Identifizierung und Differenzierung der Campylobacter-fetus-Subspezies mittels PCR. Dtsch. tierärztl. Wschr. 110, 55-59.
- F. Schulze, A. Bagon, W. Müller, H. Hotzel "Identification of Campylobacter fetus subspecies by phenotypic differentiation and PCR", J. Clin. Microbiol. 44, 2019-2024, 2006
State from the 24/11/2010