Immunization with Brucella melitensis Rev 1 against Brucella ovis infection of rams

The efficacy of Brucella Melitensis Rev 1 vaccine (Rev 1) for the prophylaxis of Brucella ovis ram epididymitis was evaluated. Twenty-nine 3-month-old rams were vaccinated with 2 X 10(9) Rev 1 and 14 were revaccinated with 5 X 10(8) at 14 months of age. Six rams remained unvaccinated as a control group. All rams were challenged with 5 X 10(8) B. ovis at 21 months of age. Before being slaughtered 8 weeks later, only one vaccinated ram developed epididymitis while four of the six control rams developed testicular alterations. Genital and selected extragenital organs and lymph nodes were removed at slaughter and inoculated on selective media. B. ovis was isolated from 26.6% of the vaccinated rams, 21.4% of the revaccinated rams and 100% of control rams. Portions of epididymis, testes and vesicular glands were also used for pathological studies. More severe lesions were observed in control rams than in vaccinated ones. In conclusion, these results show that vaccination of young lambs, followed or not by revaccination, is a suitable method for the prophylaxis of B. ovis infection of rams.     

Association of sexual experience with isolation of various bacteria in cases of ovine epididymitis

Testicles from rams in flocks experiencing ram epididymitis in Idaho and eastern Oregon were cultured. Twenty-six breeding rams from 6 flocks were cultured and only Brucella ovis was isolated. Virgin rams (65) harbored numerous species of small fastidious gram-negative rods, including Actinobacillus actinomycetemcomitans, Haemophilus spp, Moraxella spp, and Pasteurella spp. Thus, there appeared to be 2 separate disease entities, dependent on sexual experience of the animal.     

Correlation of the presence of seminal white blood cells and the prevalence of separated spermatozoal heads with subclinical Brucella ovis infection in rams

A breeding soundness evaluation was conducted on 824 Colorado range rams. These rams were determined to be free from epididymitis via testicular palpation. Semen evaluation included microscopic observation for the presence of WBC. Of the 824 rams, 15.5% failed the breeding soundness evaluation on the basis of the semen evaluation: 10.6% had WBC in the semen and 4.9% had poor sperm morphology. The prevalence of Brucella ovis isolation varied from 0% to 16.2% within flocks. The prevalence of subclinical B ovis infection was 10% in the control flocks. Brucella ovis was isolated from 71.9% of the rams that had WBC in their semen. From this study, it appeared that palpation and vaccination may be inadequate for control of ram epididymitis.     

Epidemiological Observations in a Corriedale Flock affected by Brucella ovis

Brucellosis in sheep, caused by Brucella ovis, is primarily a chronic infectious disease of rams with epididymitis as its most characteristic lesion. Six hundred rams from an infected farm were clinically and serologically examined once a year, over a 3-year period. An increase from 2.1% to 6.3% in the prevalence of animals serologically positive to B. ovis occurred over the 3 years. However, the prevalence of rams with lesions in the reproductive tract declined from 14.2% to 6.5% in the third year following one year of strict culling of clinically affected and rams that were serologically positive for B. ovis. Clinical lesions found in the 179 affected rams fell into two main categories: rams with epididymitis and rams with affected lymph nodes. These results suggest that the prevalence of the disease relates mainly to the sexual activity of the animal and not to age in itself. A single cull based on the results of clinical examination and serological test results was unable to decrease the prevalence of B. ovis in an extensive Corriedale sheep flock.     

病绵羊体内分离的拟似绵羊附睾种布氏菌的首次系统鉴定与分类

我们对新疆地方病防治研究所近年来从患附睾炎的公绵羊精液中分离出１５株拟似布氏菌，除按常规检定外，还采用了Ｓ群及Ｒ群噬菌体裂解试验、绵羊附睾种血清的试管凝集反应，并对有的菌株做了ＤＮＡ Ｇ＋Ｃｍｏｌ％含量测定，最后判定：在这十五株菌中有７株为绵羊附睾种布氏菌。     

Serodiagnosis of Histophilus ovis-associated epididymitis in rams

An ELISA for the detection of antibodies to Histophilus ovis was used to evaluate the association of epididymal lesions in rams with serologic response to His ovis. Comparison of ELISA results for His ovis in groups of rams with epididymal lesions with ELISA results of clinically normal rams (control group) revealed a significant difference (P less than 0.01) between the control group and those rams from which His ovis was isolated. A significant difference (P less than 0.01) was noticed between the control group and rams with lesions from which an organism other than His ovis or Brucella ovis was isolated. Additionally, a significant difference (P less than 0.01) was noticed in ELISA results between the control group and affected rams from which no organism was recovered and in which the epididymal lesion was not limited to the head of the epididymis. A difference was not detected in the His ovis ELISA results between control rams and rams with lesions associated with a B ovis infection or rams from which no organism was recovered and in which the epididymal lesion was limited to the head of the epididymis. The serologic findings in our study suggest that His ovis is more important in the development of epididymitis in rams than culture results alone would indicate.     

Brucella ovis excretion in semen of seronegative, clinically normal breeding rams

A commercial flock of Suffolk and Suffolk-cross breeding rams was monitored for 5 years in an effort to control epididymitis caused by Brucella ovis. Scrotal palpation, semen evaluations, and vaccination against B ovis were used the first 3 years. Serologic evaluation (complement fixation and ELISA) was added the fourth year, and bacteriologic culturing was added to the program the fifth year. Semen culturing in the fifth year revealed 9 (37.5%) of 24 rams were actively excreting B ovis; 6 of those 9 rams were seronegative. Neither semen quality nor the presence of WBC in the semen were dependable criteria to detect these seronegative carriers. In spite of the high percentage of B ovis excretors, few clinical signs of epididymitis were detected in the flock during the last 3 years of the study. It was hypothesized that vaccination protected rams against the clinical disease but not the carrier state. The importance of culturing semen for assessment of a control program was emphasized.     

Clinical and immunological responses of ewes following vaccination with an experimental formalin-inactivated Chlamydia psittaci (ovis) vaccine and subsequent challenge with the live organism during pregnancy

The protection afforded by an experimental, killed, adjuvanted vaccine derived from the A22 strain of Chlamydia psittaci (ovis) against ovine enzootic abortion was studied. The vaccine was used undiluted (group A), at a dilution of 10(-3) (group B) and at a dilution of 10(-6) (group C). A fourth control group (group D) was inoculated with all components of the vaccine except the chlamydial antigen. A group of rams (group R) was also vaccinated with the chlamydial antigen diluted to 10(-3). Animals were challenged 70 days after mating with the A22 strain of C. psittaci (ovis) and were studied throughout pregnancy and the subsequent lambing period. Their cell-mediated immune responses were examined using a skin test and their humoral immune responses were studied using an ELISA. Tests for excretion of chlamydiae in their faeces and genital tract during pregnancy and after parturition and in the faeces of their lambs were made. The reproductive performance of the ewes was assessed by calculating the average weight of lambs produced per ewe in each group. The experimental vaccine protected the ewes in groups A and B against challenge with C. psittaci (ovis) as none showed clinical signs of OEA or excreted chlamydiae. The average weight of lambs produced per ewe in both groups was greater than 4 kg. Both groups seroconverted after vaccination but not all of them were positive to the skin test. The experimental vaccine at 10(-6) dilution of antigen did not protect the ewes as three of 10 ewes displayed clinical OEA and excreted chlamydiae in the products of parturition.(ABSTRACT TRUNCATED AT 250 WORDS)     

Bacterial isolates associated with epididymitis in rams from Idaho and eastern Oregon flocks.

Testicles from 47 rams with palpable lesions of epididymitis were subjected to bacterial culture. Of the testicles examined by culture technique, 49% were positive for bacterial growth. The 2 most frequent isolates were Actinobacillus actinomycetemcomitans (23.4% of the testicular pairs) and Brucella ovis (14.9% of the testicular pairs). Heretofore A actinomycetem-comitans has not been reported as a cause of epididymitis in rams.     

Isolation of Actinobacillus seminis from rams in the United Kingdom.

Actinobacillus seminis was isolated from the semen of five rams on four farms. Four of the rams had abnormal semen and three were also infertile. The isolates of A seminis showed similar phenotypic profiles and electrophoretic protein patterns to the type strain of A seminis but were distinct from Histophilus ovis previously isolated from rams with epididymitis in Scotland. The infection appeared to be subclinical but two of the five rams had palpable abnormalities of their testes. Three rams were treated with antibiotics but the infection persisted. No gross lesions were found in the genitalia of two of three rams examined post mortem but one had necrotic abscesses in the testes and epididymis. A seminis was isolated from the seminal vesicles and epididymis of one ram without gross lesions but not from the genitalia of the other two. On one farm the infection in a recently purchased ram led to the detection of another case as a result of the bacteriological screening of 11 stock rams not in contact with the initial case. These five subclinical cases, which included a supposedly healthy stock ram, suggest that A seminis infection may be widespread and should be considered in cases of infertility.     

Actinobacillus seminis infection in sheep in the Republic of South Africa. I. Identification of the problem

A clinical palpation and semen smear examination of 647 rams submitted to the Regional Veterinary Laboratory during 1967 revealed that 42 (6,5%) of these animals had clinical epididymitis or orchitis, 6 (0,9%) showed other types of genital lesions and 98 (15,1%) suffered from subclinical genital infection. A. seminis and A. seminis-like organisms were isolated from semen specimens of 18 out of 35 rams with clinical epididymitis or orchitis, 25 out of 33 rams with subclinical infection and none out of 13 rams which showed no neutrophils in their semen. On 4 stud farms where Elberg Rev. 1 vaccine was meticulously applied and the complete absence of Brucella ovis infection was established, of a total of 327 rams examined, 10 (3,6%) were found to be clinically and 72 (22,0%) subclinically affected. A. seminis was isolated from 5 out of 6 of these rams with clinical lesions and 10 out of 15 of those which showed evidence of subclinical infection.     

Observations on the eradication of Brucella ovis infection from a ram flock

The measures taken to eradicate Brucella ovis infection from a naturally infected flock of 64 rams are described. Lesions of epididymitis were detected in 18 rams, all of which gave either positive or suspicious reactions in the complement fixation test. A further 20 rams gave serological reactions in the complement fixation test. Subsequently, semen was collected from 14 of these 20 rams and B. ovis was cultured from the semen of all 14 rams. Serum samples from two rams failed to react in the complement fixation test. However, they were identified as infected with the aid of an enzyme-linked immunosorbent assay and the subsequent culture of semen samples. It is suggested that, when eradicating B. ovis infection from ram flocks, the enzyme-linked immunosorbent assay be used in addition to both the complement fixation test and the physical examination. Using a combination of tests as described can increase the likehood of an earlier eradication of B. ovis infection.     

Detection of antibody in rams with contagious epididymitis, using the enzyme-linked immunosorbent assay

An enzyme-linked immunosorbent assay, using whole-cell and sonicated antigens prepared from Brucella ovis, Actinobacillus seminis, and Actinobacillus seminis-like cultures isolated from rams in Wyoming, was able to detect antibody to these antigens in rams with epididymitis. The whole-cell antigens used in this procedure gave lower background values, compared with those of the sonicated antigens. The procedure was able to detect antibody in rams before clinical signs of epididymitis became apparent.     

Prevalence of Histophilus ovis and Actinobacillus seminis in the genital tract of sheep

Histophilus ovis and Actinobacillus seminis were isolated from the preputial cavity of 6-month-old rams and the vagina of 6-month-old ewes at a substantially higher rate than that in mature (greater than 2 years old) rams and ewes. These organisms appeared to be a transitory component of the ovine genital flora, the prevalence of which was associated with age regardless of gender. Additional evaluation of the recoverability of H ovis and A seminis from the preputial cavity of rams from birth to 1 year of age indicated that the isolation rate from rams and predominance of the organisms in the preputial cavity differed greatly over this age period. These organisms were not recoverable until ram lambs were 12 weeks of age and were most prevalent at 20 weeks of age, after which recoverability of H ovis and A seminis from the preputial cavity steadily decreased, continuing through the time of the last evaluation at 1 year of age. The time period with which these organisms can be isolated from the preputial cavity is closely correlated with the time period when epididymitis associated with these organisms develops, and may be an important factor in the pathogenesis of epididymitis.     

Characterisation of Histophilus ovis and related organisms by restriction endonuclease analysis

The banding profiles generated by Bam H1 restriction endonuclease cleavage of bacterial DNA from clinical and reference isolates of Histophilus ovis, Haemophilus somnus and related bacteria were compared. H. ovis, H. somnus and Haemophilus agni isolates were found to have distinct similarities in banding profiles characterised by 10 common bands between 2.0 and 9.6 kilobases (kb). The close taxonomic relationship of these isolates was reinforced by these findings. The reference isolates examined in this study--Actinobacillus lignieresii, Actinobacillus seminis, H. agni, H. somnus, H. ovis, Haemophilus influenzae, Haemophilus parainfluenzae, Haemophilus parahaemolyticus--could be distinguished from each other on the basis of their characteristic banding profiles. Actinobacillus sp were observed to have more bands between 2 and 23 kb compared with the H. ovis and Haemophilus sp isolates studied. Analysis of isolates from an experimental infection trial illustrated the potential of restriction endonuclease analysis in molecular epidemiological applications. It was possible to demonstrate by this means that the post-challenge isolates had identical banding profiles to the challenge (or infecting) isolate which had a distinctly different banding profile from that of pre-challenge H. ovis isolates. Furthermore, restriction endonuclease analysis of H. ovis isolates obtained from follow-up investigations of a recurrent problem of epididymitis in unmated rams, indicated that the H. ovis isolates implicated in epididymitis, were present as a single strain in a number of sheep over a period of time. This suggested that the mechanism of transmission was by perinatal perputial contamination.     

Efficacy of long-acting oxytetracycline alone or in combination with streptomycin for treatment of Brucella ovis infection of rams

Twenty-four rams inoculated with Brucella ovis by conjunctival and preputial routes were treated with a long-acting oxytetracycline alone or in combination with dihydrostreptomycin sulfate. The combined treatment eliminated Brucella ovis from 11 of 12 (91.6%) treated rams. Only 4 of 12 (33.3%) rams treated with oxytetracycline alone were bacteriologically negative. Neither treatment resolved clinical epididymitis in 2 rams affected before treatment. Many rams had pathologic lesions in the epididymis and ampullae, which limited the efficacy of antibiotic treatment.     

Association of age of ram with distribution of epididymal lesions and etiologic agent

A 2-year study of the frequency of isolation of various organisms from mature and yearling rams with epididymitis was conducted at the US Sheep Experiment Station at Dubois, Idaho. Investigation into the distribution of lesions in the epididymis in relation to age of the ram also was studied. Serologic or bacteriologic evidence of Brucella ovis infection was demonstrated in 79.5% of the mature rams with epididymal lesions. Actinobacillus seminis and Histophilus ovis were the 2 most frequently isolated organisms from yearling rams with lesions. The tail(s) of the epididymis was the most frequent site of lesion development in the mature rams (86.4%). Yearling rams developed lesions twice as frequently in the tail(s) of the epididymis as in the head(s) of the epididymis. When lesions were localized in the head(s) of the epididymis, an etiologic agent usually was not demonstrated.     

Anti-chlamydial immunity in ewes conferred by vaccination with a combination of three live chlamydia, brucella and salmonella vaccines

Live attenuated vaccines against Chlamydia psittaci var ovis, Brucella melitensis and Salmonella abortus ovis have previously been shown to be compatible in mice by subcutaneous administration. Immunity against challenge with virulent chlamydia was, however, slightly decreased in associations including the B melitensis Rev 1 vaccine. The chlamydia strain 1B vaccine was administered to four- to five-month-old female lambs, either alone or in combination with the B melitensis Rev1 and the S abortus ovis Rv6 vaccines. Clinical, serological and bacteriological observations demonstrated the compatibility of the three vaccines. Control, singly and triply vaccinated ewes were challenged with a virulent strain of chlamydia during their second pregnancy, 15 months after vaccination. Five of the 12 control ewes lambed normally and 10 of them were infected, as shown by the excretion of the challenge chlamydia in genital secretions. Sixteen of the 17 ewes in the triple vaccine group lambed normally and none was infected. All 12 in the single vaccine group lambed normally and three of the 12 were infected. In spite of this unusually poor protection by the single vaccine, antichlamydial immunity was clearly not decreased by the association with the two other vaccines.     

Multiplex PCR for the detection of Brucella ovis, Actinobacillus seminis and Histophilus somni in ram semen

OBJECTIVE: To develop a multiplex polymerase chain reaction (PCR) assay for the rapid detection of Brucella ovis, Actinobacillus seminis, Histophilus somni in fresh ram semen samples. DESIGN: The multiplex assay was based on the single PCR assays published for the detection of A seminis and B ovis, and the forward primer published for the detection of H somni; an alternative reverse primer for H somni was designed in this study. PROCEDURE: Culture and PCR of 295 fresh semen samples were carried out. RESULTS: The multiplex PCR was far more successful in the detection of H somni (45/295) than culture (23/295). A seminis was also detected in more semen samples by multiplex PCR (29/295) than culture (13/295) and B ovis was detected in three samples using both PCR and culture. No amplifications were detected with DNA from a range of bacterial isolates including species associated with epididymitis in rams. CONCLUSION: This PCR could be used as a complementary test, or alternative to culture of ram semen and other biological samples for the detection B ovis, H somni and A seminis.     

Serology and semen culture for the diagnosis of Brucella ovis infection in chronically infected rams

The serological response to Brucella ovis and the shedding of the organism in semen was followed for a period of 13-14 months in 42 naturally infected rams. Most rams remained chronically infected and excreted the organism in their semen throughout the investigation. B. ovis was isolated from 87.9% of the semen samples from the infected rams. The most common sites from which B. ovis could be isolated at necropsy were the epididymides and accessory sexual glands. In one ram the organism was isolated from lung, spleen, kidney and iliac lymph nodes. Three rams ceased to shed B. ovis in their semen during the course of the investigation. Seventy-five (11%) of 686 sera from infected rams were negative in the complement fixation test (CFT) although 76% and 77% of CFT-negative sera were positive in the gel diffusion precipitin test (GDT) and enzyme labelled immunosorbent assay (ELISA) respectively. The high incidence of CFT-negative infected rams was due to the selection for the investigation of many rams with histories of negative or vacillating CFT titres. Sera from five rams which never shed B. ovis in their semen reacted erratically in the three serological tests. The five rams were from heavily infected flocks and were kept in contact with infected rams throughout the investigation.