CAMPYLOBACTERIOSIS
This is probably the most typical venereal infection capable of impairing herd fertility, for it is capable of causing both herd infertility and endemic infertility. It occurs throughout Europe and North America, but is at present only sporadic in
Romania, Czechoslovakia, Netherlands, France, Cyprus and Great Britain.
The following species and subspecies are now recognised on the basis of serotyping and cultural and biochemical properties : C. fetus venerealis, C. fetus fetus serotype A, C. fetus fetus serotype B, C. fetus sputorum bubulus.
Their occurrence and role varies from country to country, and from one regionn to another. Bell (1984) reported that in Great Britain typical herd infertility is caused by C. fetus subsp. venerealis, while C. fetus subsp. fetus is associated with sporadic abortion, or in certain regions, herd infertility. Polak and Rysanek (1984) in Czechoslovakia found that C. fetus subsp. fetus occurred in herds of imported cattle.
Vanderlasche (1982) categorised the occurrence of different strains as follows :
— infertility : 90% caused by C. fetus venerealis A, 10% caused by C. fetus fetus B, rarely C. fetus fetus A;
— abortion only : C. fetus fetus A and B.Campylobacter sputorum bubulus is considered to be a saprophyte, present in
vaginal and preputial secretions, semen, fetuses and the placenta. Its presence may complicate laboratory diagnosis.
The serum of animals which have recovered from Campylobacter infection contains thermostable type O agglutinins, belonging to all three classes of immunoglobulins
(IgG, IgM and IgA), and also local thermostable and thermolabile agglutinins belonging to class IgA. However, females which have never been in contact with the disease may possess type O agglutinating antibodies in their serum as a
result of « infection » with the intestinalis biotype or the subspecies C. sputorum bubulus.
The infection is insidious in the male, being generally inapparent, without lesions, without symptoms and with no change in semen quality (even though the semen may become contaminated with Campylobacter). This makes detection difficult, particularly when coupled with the lability of the bacteria outside the host (rapid destruction upon exposure to light; destruction in 5 min at 58°C). Transmission takes place almost exclusively by mating or insemination (and also between
male animals in close contact). It is impossible to establish a diagnosis on clinical grounds (prolonged oestrus cycles, repeated return to oestrus, increased number of
inseminations required for each conception, prolonged interval between calving and conception, increased occurrence of abortion at 3-8 months of gestation). Moreover, under extensive husbandry and in beef suckler herds the disease will become
more firmly established than in a dairy herd, because of the inevitable delay before a diagnosis is made. The bacteria remain confined to the vagina in only 25% of cows (which can have a normal pregnancy). More often the bacteria migrate along the genital tract, invading the body of the uterus and reaching the uterine horns 7- 10 days after vaginal contamination. In about 15-20% of cows, infection of the
oviducts results in salpingitis.
It is a self-limiting disease, which means that infected animals undergo spontaneous cure. The different classes of antibodies behave differently : IgA is formed in the cervix and vagina, where it may persist for some 10 months, while IgG is dominant
in the uterus. These antibodies may prevent reinfection, but their presence does not mean that the female is no longer shedding Campylobacter.
Diagnosis depends on identification of the bacteria by direct microscopy or by culture.
Material and methods have been detailed in the norm laid down in March 1984 by the Norms Commission of the O.I.E., presented at the General Session of the Committee on 21-25 May 1984.
The most reliable type of sample is a preputial washing (made with broth medium or normal saline). Tedesco et al. (1977) compared three methods for taking samples from bulls and obtained the most uniform and precise results with the
« scraping » technique devised for trichomoniasis by Sutka et al. (1969). The mucous membrane of the preputial sac is scraped with a grooved metal or plastic rod, and the method has given excellent results (Guérin, 1984). However, it should
never be used in large herds unless disposable rods are available, one for each animal.
Another diagnostic technique for bulls is immunofluorescence (Clark et al., 1978), applied directly to fresh semen samples or to cultures prepared from them.
It gives precise, reliable and specific results, and is well suited for testing contaminated samples, even those containing few Campylobacter, after their life span outside the host has expired. Proper preservation of a sample to be sent to a laboratory is difficult, since Campylobacters cannot survive for more than 6 hours. Consequently, to ensure a reliable result from cultures, it is necessary to sow the culture on site, or to use a storage and enrichment medium if culture is to be performed later. In France, the « Laboratoire de Contrôle des Reproducteurs » uses SBL storage medium derived
from that proposed by Gastrin et al. (1968). Other solid media (for swab samples) and fluid media have also been proposed for storage alone (Clark et al., 1978), or both storage and enrichment (Bell, 1984). These techniques allow 9 5% of the bacteria to survive for 48 h, with a maximum life of 6-7 days (reduced in the presence of contaminants). A pure culture of Campylobacter keeps for about 3 weeks in such media. Storage and/or enrichment media should contain antibiotics (such as bacitracin, polymyxin, novobiocin or cycloheximide) to suppress contaminants.
The result is also influenced by the conditions of culture during incubation at 37°C, the best results being obtained with an atmosphere composed of 87% nitrogen,
5% oxygen and 8% carbon dioxide, and by using thiol medium plus antibiotics to control contaminants. The cultures are examined after 2, 3, 4, 5 and 6 days of culture — colonies usually form after about 4 days.
Serological tests on mucus and/or blood serum are of minor importance because of variable results and uncertainty concerning the source of the antibodies detected (perhaps being due to non-pathogenic strains).
Conventional therapy with antibiotics (streptomycin or erythromycin) has been abandoned because of false cures in both males and females, and the adverse effects on semen production by bulls. Vaccination of bulls infected with C. fetus
fetus does not by itself lead to a certain and permanent cure. On the other hand, Fischerleitner (1984) showed that two inoculations of C. fetus fetus vaccine, a month apart, coupled with infusion of an intramammary formulation of antibiotics
into the prepuce, or with intramuscular injection of streptomycin or intravenous injection of erythromycin, can produce a satisfactory bacteriological cure of breeding
bulls, with little effect on semen production.
Such treatment always requires the frequent application of reliable diagnostic - procedures to detect the bacteria, in order to confirm complete recovery before the bull is returned to service.
It is rare for females to be treated, except for vaccination, renewed annually.
While the disease is self-limiting in individual animals, waves of recurrence tend to occur in a herd. A female may excrete Campylobacter for two years after infection.
Prophylaxis is based on isolating the breeding herd, rigorous examination of bulls brought into the herd, and the use of AI with semen from disease-free bulls. In general,bulls should be checked before being used for service (they should come from a
herd known to be free from reproductive disorders, and a representative sample of animals should be negative to diagnostic tests) and subsequently twice a year.
In Great Britain, before a bull is used and while it is still in quarantine, it is routinely treated with an oily gel containing penicillin and streptomycin, introduced
into the prepuce on three consecutive days (Bell, 1984).
The extensive use of AI coupled with rigorous application of technical and health surveillance, has practically eradicated the disease from countries previously heavily infected. However, occasional accidental infection still occurs, sometimes
with rapid recurrence (perhaps due to infection with a new strain; Bell, 1984). It must be remembered that even a vaccinated bull can act as a passive vector after it
has served an infected cow.
This is probably the most typical venereal infection capable of impairing herd fertility, for it is capable of causing both herd infertility and endemic infertility. It occurs throughout Europe and North America, but is at present only sporadic in
Romania, Czechoslovakia, Netherlands, France, Cyprus and Great Britain.
The following species and subspecies are now recognised on the basis of serotyping and cultural and biochemical properties : C. fetus venerealis, C. fetus fetus serotype A, C. fetus fetus serotype B, C. fetus sputorum bubulus.
Their occurrence and role varies from country to country, and from one regionn to another. Bell (1984) reported that in Great Britain typical herd infertility is caused by C. fetus subsp. venerealis, while C. fetus subsp. fetus is associated with sporadic abortion, or in certain regions, herd infertility. Polak and Rysanek (1984) in Czechoslovakia found that C. fetus subsp. fetus occurred in herds of imported cattle.
Vanderlasche (1982) categorised the occurrence of different strains as follows :
— infertility : 90% caused by C. fetus venerealis A, 10% caused by C. fetus fetus B, rarely C. fetus fetus A;
— abortion only : C. fetus fetus A and B.Campylobacter sputorum bubulus is considered to be a saprophyte, present in
vaginal and preputial secretions, semen, fetuses and the placenta. Its presence may complicate laboratory diagnosis.
The serum of animals which have recovered from Campylobacter infection contains thermostable type O agglutinins, belonging to all three classes of immunoglobulins
(IgG, IgM and IgA), and also local thermostable and thermolabile agglutinins belonging to class IgA. However, females which have never been in contact with the disease may possess type O agglutinating antibodies in their serum as a
result of « infection » with the intestinalis biotype or the subspecies C. sputorum bubulus.
The infection is insidious in the male, being generally inapparent, without lesions, without symptoms and with no change in semen quality (even though the semen may become contaminated with Campylobacter). This makes detection difficult, particularly when coupled with the lability of the bacteria outside the host (rapid destruction upon exposure to light; destruction in 5 min at 58°C). Transmission takes place almost exclusively by mating or insemination (and also between
male animals in close contact). It is impossible to establish a diagnosis on clinical grounds (prolonged oestrus cycles, repeated return to oestrus, increased number of
inseminations required for each conception, prolonged interval between calving and conception, increased occurrence of abortion at 3-8 months of gestation). Moreover, under extensive husbandry and in beef suckler herds the disease will become
more firmly established than in a dairy herd, because of the inevitable delay before a diagnosis is made. The bacteria remain confined to the vagina in only 25% of cows (which can have a normal pregnancy). More often the bacteria migrate along the genital tract, invading the body of the uterus and reaching the uterine horns 7- 10 days after vaginal contamination. In about 15-20% of cows, infection of the
oviducts results in salpingitis.
It is a self-limiting disease, which means that infected animals undergo spontaneous cure. The different classes of antibodies behave differently : IgA is formed in the cervix and vagina, where it may persist for some 10 months, while IgG is dominant
in the uterus. These antibodies may prevent reinfection, but their presence does not mean that the female is no longer shedding Campylobacter.
Diagnosis depends on identification of the bacteria by direct microscopy or by culture.
Material and methods have been detailed in the norm laid down in March 1984 by the Norms Commission of the O.I.E., presented at the General Session of the Committee on 21-25 May 1984.
The most reliable type of sample is a preputial washing (made with broth medium or normal saline). Tedesco et al. (1977) compared three methods for taking samples from bulls and obtained the most uniform and precise results with the
« scraping » technique devised for trichomoniasis by Sutka et al. (1969). The mucous membrane of the preputial sac is scraped with a grooved metal or plastic rod, and the method has given excellent results (Guérin, 1984). However, it should
never be used in large herds unless disposable rods are available, one for each animal.
Another diagnostic technique for bulls is immunofluorescence (Clark et al., 1978), applied directly to fresh semen samples or to cultures prepared from them.
It gives precise, reliable and specific results, and is well suited for testing contaminated samples, even those containing few Campylobacter, after their life span outside the host has expired. Proper preservation of a sample to be sent to a laboratory is difficult, since Campylobacters cannot survive for more than 6 hours. Consequently, to ensure a reliable result from cultures, it is necessary to sow the culture on site, or to use a storage and enrichment medium if culture is to be performed later. In France, the « Laboratoire de Contrôle des Reproducteurs » uses SBL storage medium derived
from that proposed by Gastrin et al. (1968). Other solid media (for swab samples) and fluid media have also been proposed for storage alone (Clark et al., 1978), or both storage and enrichment (Bell, 1984). These techniques allow 9 5% of the bacteria to survive for 48 h, with a maximum life of 6-7 days (reduced in the presence of contaminants). A pure culture of Campylobacter keeps for about 3 weeks in such media. Storage and/or enrichment media should contain antibiotics (such as bacitracin, polymyxin, novobiocin or cycloheximide) to suppress contaminants.
The result is also influenced by the conditions of culture during incubation at 37°C, the best results being obtained with an atmosphere composed of 87% nitrogen,
5% oxygen and 8% carbon dioxide, and by using thiol medium plus antibiotics to control contaminants. The cultures are examined after 2, 3, 4, 5 and 6 days of culture — colonies usually form after about 4 days.
Serological tests on mucus and/or blood serum are of minor importance because of variable results and uncertainty concerning the source of the antibodies detected (perhaps being due to non-pathogenic strains).
Conventional therapy with antibiotics (streptomycin or erythromycin) has been abandoned because of false cures in both males and females, and the adverse effects on semen production by bulls. Vaccination of bulls infected with C. fetus
fetus does not by itself lead to a certain and permanent cure. On the other hand, Fischerleitner (1984) showed that two inoculations of C. fetus fetus vaccine, a month apart, coupled with infusion of an intramammary formulation of antibiotics
into the prepuce, or with intramuscular injection of streptomycin or intravenous injection of erythromycin, can produce a satisfactory bacteriological cure of breeding
bulls, with little effect on semen production.
Such treatment always requires the frequent application of reliable diagnostic - procedures to detect the bacteria, in order to confirm complete recovery before the bull is returned to service.
It is rare for females to be treated, except for vaccination, renewed annually.
While the disease is self-limiting in individual animals, waves of recurrence tend to occur in a herd. A female may excrete Campylobacter for two years after infection.
Prophylaxis is based on isolating the breeding herd, rigorous examination of bulls brought into the herd, and the use of AI with semen from disease-free bulls. In general,bulls should be checked before being used for service (they should come from a
herd known to be free from reproductive disorders, and a representative sample of animals should be negative to diagnostic tests) and subsequently twice a year.
In Great Britain, before a bull is used and while it is still in quarantine, it is routinely treated with an oily gel containing penicillin and streptomycin, introduced
into the prepuce on three consecutive days (Bell, 1984).
The extensive use of AI coupled with rigorous application of technical and health surveillance, has practically eradicated the disease from countries previously heavily infected. However, occasional accidental infection still occurs, sometimes
with rapid recurrence (perhaps due to infection with a new strain; Bell, 1984). It must be remembered that even a vaccinated bull can act as a passive vector after it
has served an infected cow.
