Early sequential findings in the genitalia of rams experimentally infected with Actinobacillus seminis

AIM: To investigate and assess the sequential pathological changes in the epididymis and testis of young rams injected intra-epididymally with Actinobacillus seminis. METHODS: Twenty yearling Suffolk and Suffolk-cross rams were randomly divided into two groups comprising 16 test and four control animals. Each test ram received 2.3 x 109 cfu/ml of A. seminis injected intra-epididymally. Every 24 h post-inoculation (p.i.), two test rams were randomly selected, euthanised, and necropsied, until the end of the experiment at 192 h p.i. One control animal was euthanised at 24 h, 48 h, 96 h and 144 h p.i., respectively. The reproductive tract of each ram was carefully examined, lesions photographed, and tissues cultured. Thin sections of tissue samples were fixed and examined by light microscopy; additionally, epididymal tissues were examined by scanning electron microscopy (ScEM). RESULTS: Gross lesions were observed in the cauda epididymis of all test rams, and ranged from swelling at 24 h p.i. through enlargement and granuloma formation from 72 h p.i., to gradual enlargement and increasing firmness by 192 h p.i. Gross testicular atrophy was observed in three rams. Histologically, spermatic granulomas were evident in the epididymis and the tunica vaginalis of 10 and four rams, respectively. Cauda epididymitis was present in all rams, and caput and corpus epididymitis in eight and four rams, respectively. Interstitial orchitis was observed in seven, testicular degeneration in 14, and localised and diffuse tunica vaginalitis in 12 rams. Epididymal vasculitis and infiltration of eosinophils were observed as early as 24 h p.i. Moderate disruption of the epididymal duct from 72 h p.i., with subsequent release of spermatozoa into the interstitium, was revealed by ScEM. Actinobacillus seminis was cultured from the granuloma of six test rams from 72 h p.i. CONCLUSIONS: Actinobacillus seminis has the ability to persist in the genitalia of young rams following experimental infection. Suppurative epididymitis is observed as early as 24 h p.i., and spermatic granuloma within 72 h p.i. Infiltration of eosinophils appears to be an early host response to the bacterium, and may play a role in the pathogenesis of the epididymitis.     

Experimental transmission of Actinobacillus seminis infection to rams

Nine groups of four 18- to 24-month-old rams were inoculated with Actinobacillus seminis by the following routes: intraconjunctival, intranasal, oral, intravenous, intramuscular, intraepididymal, vas deferens, intraurethral or intrapreputial. Eight similar rams were left uninoculated as controls. Systemic clinical signs were minimal and were confined primarily to the inoculation sites and the scrotal contents. Mild to severe epididymitis resulted from all the routes of inoculation except intraconjunctival and intranasal. Direct inoculation into the genital tract, especially into the cauda epididymis, was more effective. Intrapreputial and intraurethral inoculation led to ascending urethral infection, and inoculation into the vas deferens resulted primarily in descending infection of the accessory sex glands. A seminis was isolated from 11 of the 36 test rams (30.6 per cent); 26 of the 36 rams, some from each of the test groups except those inoculated intravenously, reacted serologically.     

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.     

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.     

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.     

Abnormalities of the Testes and Epididymis in Bucks and Rams Slaughtered at Debre Zeit Abattoir,Ethiopia

A study was conducted at Debre Zeit export abattoir on 404 bucks belonging to four breeds and 167 rams of two breeds. The animals were selected from the slaughter flock using stratified sampling based on breed. Ante-mortem and post-mortem examinations were carried out after each animal was carefully identified. Various genital abnormalities were observed, among which testicular atrophy and epididymitis were the predominant genital problems in both bucks and rams. The prevalence of cryptorchidism was higher (p<0.05) in bucks than in rams, while epididymitis (p<0.05), sperm granuloma (p<0.01) and epididymal cysts (p<0.05) were more frequent in rams. In bucks, none of these abnormalities was significantly associated with age (p>0.05). However, testicular atrophy (p<0.01), epididymitis (p<0.01) and haemorrhagic lesions (p<0.05) were associated with breed, the prevalence being higher in Woito-Guji and Boran bucks than in the Arsi-Bale and Afar breeds. In rams, age affected (p<0.05) the incidence of testicular atrophy, epididymitis and sperm granulomas. Epididymitis, sperm granuloma and epididymal cysts were more frequent (p<0.01) in Adal rams than in Black Head Somalis.     

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.     

TESTICULAR PATHOLOGY OF MERINO RAMS

SUMMARY The scrotal contents of 2,281 Merino rams of wide age range examined at 3 abattoirs in Perth, Western Australia, showed a 40% prevalence of rams with 1 or more gross lesions. The percentage prevalence of gross lesions found on autopsy were: adhesions 21, testicular atrophy/hypoplasia 14, testicular calcification 13, congenital cyst of the epididymis 6, cryptorchidism 4, chronic epididymitis/scrotal abscesses 2, varicocoele 2, testicular aplasia1, seminoma1. The prevalence of lesions increased with age of rams. Testicular atrophy was often present when varicocoele, chronic epididymitis and scrotal abscess affected that side of the scrotal sac. Corynebacterium spp was the most frequent isolate from chronic epididymitis. Actinobacillus seminis was isolated once and Brucella ovis was not isolated. About 20% of the rams showed lesions compatible with a diagnosis of reproductive unsoundness. A large proportion of lesions were revealed only after removal of the scrotum and most of these did not appear to affect normal spermatogenesis except for an estimated 9% of rams, which showed mild atrophy/hypoplasia. Samples of these testes showed mild to moderate changes in spermatogenesis on histopathology. It was postulated that the latter group of rams might represent those ill-defined clinical cases which show equivocal results on appraisal of semen samples despite the presence of palpably normal testes.     

B-mode real time ultrasonographic imaging of the testis and epididymis of sheep and goats

Ten male goats and five rams were examined from 11 and 15 weeks of age, respectively, for six months to study the ultrasonic appearance of normal testes and epididymides before and after puberty. Five adult rams with lesions of these organs were also examined. A portable, B-mode, real time scanner fitted with a 7.5 MHz, linear array transducer was used. The testis appeared as a homogeneous and moderately echogenic structure with a centrally located mediastinum testis represented by an hyperechogenic line in images taken in the longitudinal plane and by an almost circular spot in transverse images. The testicular capsule and skin were evident as a distinct hyperechogenic line encircling the testicular parenchyma. A thin non-echogenic layer of fluid, presumably between two layers of tunica vaginalis, was observed. The tail of the epididymis was more heterogeneous and less echogenic than the testis. The epididymal head was also less echogenic but homogeneous in texture, and the body of the epididymis was difficult to image. The pampiniform plexus was easily identified as numerous convoluted sonolucent tubular structures. The ultrasonic images of possible cases of epididymitis, spermatocele, testicular cyst and abscess and scrotal hernia are described.     

SPERMATIC GRANULOMA IN THE RAM: DIAGNOSIS BY ULTRASONOGRAPHY AND SEMEN CHARACTERISTICS

Ultrasonographic appearance of the testis and epididymis, and seminal characteristics, with regard to localization of spermatic granuloma were studied. In rams with spermatic granuloma (n = 9), diagnosed by clinical or ultrasonographic examinations before histopathological confirmation, localization of each lesion was recorded. Epididymal granulomas, caput and cauda, were seen as anechoic or hyperechoic areas with a distinct margin with or without a hyperechoic capsule. Granulomas in the testis were microscopic and, therefore, could not be detected by ultrasonography. Enlargement in the mediastinum testis was detected in all rams when there were granulomas in the caput. Heterogeneous testis parenchyma invaded by numerous hyperechoic foci, representing testicular degeneration, was associated with granulomas both in the epididymis and testis. Ultrasonographic appearance of the lesions did not differ with regard to season. Seminal characteristics varied between rams. It was concluded that ultrasonographic evaluation may give valuable information in the diagnosis of sperm granuloma in the ram.     

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.     

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.     

不同繁殖季节成年牦牛附睾组织特征比较

为比较不同繁殖季节成年牦牛附睾组织结构特征变化,应用苏木精-曙红常规染色、Masson's和Gomori's特殊组织化学染色方法比较不同繁殖季节牦牛（6头繁殖期成年牦牛和9头繁殖间期成年牦牛）附睾的组织结构特点并用IPP图像分析软件进行定量分析。结果显示,与繁殖间期相比,繁殖期附睾尾间质胶原纤维和网状纤维较附睾头及附睾体明显增多;附睾头和附睾体柱状上皮厚度显著增加（P<0.05）,附睾头纤毛长度增加显著（P<0.05）;附睾头和附睾尾管腔内径及外径显著增高（P<0.05）;但是附睾尾管腔外径繁殖期与繁殖间期相比差异不显著（P>0.05）。本研究结果表明,成年牦牛附睾管外围网状纤维与胶原纤维分布一致,二者在附睾尾较为丰富,可能与其较强的收缩能力及精子运输有关;柱状纤毛上皮高度及纤毛长度、管腔内径与外径的变化与其所处的不同繁殖季节密切相关,附睾管腔的膨大和回缩亦可能是高原地区季节性繁殖的哺乳动物中一种普遍存在的现象。     

Histological Characteristics of Adult Yak Epididymis in Different Breeding Seasons

To compare the histological changes of the adult yak's epididymis in different breeding seasons,six adult yak testis in breeding season and nine adult yak testis in breeding interval were collected for structure investigation by HE staining,Masson's and Gomori's histochemistry methods,and IPP (Image-Pro Plus) statistics method was used to quantitative statistics.The results showed that comparing with the adult yak in the breeding interval,the epididymis ducts of adult yak in the breeding season were covered with the columnar ciliated epithelium.The collagen and reticular fiber in cauda epididymis were obviously more abundant than caput and corpus epididymitis.And the thickness of columnar epithelium cells in caput and corpus epididymitis,the length of the cilia in caput,and also the internal and external lumen diameter of caput and corpus epididymitis were all significantly increased in the breeding season (P<0.05),but the external lumen diameter of the cauda epididymis had no significant differences (P>0.05).In conclusion,the research showed that the distribution of collagen and reticular fiber in adult yak's epididymis interstitial were similar,and they were more rich in cauda epididymis,which might relate to the capacity and the sperm transport;The changes of the epithelial thickness,the length of cilia,the internal and external lumen diameter were close related to the different breeding seasons,and it might be a common phenomenon in plateau mammals that the enlargement and reduction of the epididymal duct in different breeding seasons.     

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.     

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.     

Pathogenicity of different strains of Histophilus somni in the experimental induction of ovine epididymitis

The purpose of this study was to determine any differences in pathogenicity when sheep are experimentally infected with different Histophilus somni isolates: a) 2336 bovine origin strain; b) an isolate from ram orchitis and epididymitis; c) an isolate from the brain of a sheep with neurological signs; d) an isolate from the vagina of a clinically healthy ewe. A total of 20 rams divided in groups of 5 animals each were inoculated in the epididymis with 1 × 10⁷ CFU/mL of H. somni; a negative control group of 5 rams was used. All groups inoculated with H. somni showed some epididymitis, but the most pathology was caused by the epididymitis isolate, followed by the vaginal isolate. It was demonstrated that there is a difference in experimental infection capacity among isolates from different origins, as epididymitis occurred and the bacteria was recovered only from groups inoculated with isolates originating from epididymitis and vaginal exudate.     

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.     

A survey of congenital reproductive abnormalities in rams in abattoirs in South west England

Congenital abnormalities of the reproductive tract of male sheep were surveyed at three abattoirs in the south west of England during the period June 2000-January 2004. A total of 7307 rams were examined [6521 lambs (prepubescent) and hoggets (aged from their first autumn after birth until first shorn) and 786 adult rams mature rams that had been exposed to ewes]. A total of 156 congenital lesions were detected, 87 of which occurred in lambs. Testicular hypoplasia was the most common lesion occurring in 69 lambs as well as eight hoggets ('microtestes' were recognized in nine other animals in which the testis was disproportionately smaller than the epididymis). The second most common lesion found was notched scrotum occurring in 34 animals (27 young rams and seven adults). Some cases of notched scrotum were accompanied by hypospadias which was seen in a total of seven lambs and eight hoggets. Other lesions, detected in five or less animals (less than approximately 0.05% of the animals examined), included cryptorchidism and various abnormalities of the epididymis (segmental aplasia of the epididymis, blind efferent ducts and epididymal cyst) and congenital scrotal hernia. The overall prevalence of congenital lesions of 2.21% emphasizes the importance of undertaking breeding soundness examinations of young rams before they are put with the flock.     

Unilateral orchitis and epididymitis caused by Salmonella enterica subspecies diarizonae infection in a ram.

A case of unilateral suppurative epididymo-orchitis associated with Salmonella enterica subsp. diarizonae serovar 61:k:1,5,(7) infection is described in a 2-year-old ram. Gross lesions were characterized by severe enlargement of the scrotal contents, fibrous adhesions between testicular layers, coexistence of epididymal abscesses and foci of fibrinous exudate, and testicular atrophy. Microscopically, testicular and epididymal microabscesses and diffuse inflammatory infiltrates with abundant macrophages containing short Gram-negative rods were observed. Superimposed on the chronic lesions were fibrin deposits with clusters of neutrophils, as well as walled-off granulation tissue. Bacterial colonies were also identified in thrombosed spermatic cord vessels, scrotal lymph nodes, lung, and liver. S. enterica subsp. diarizonae serovar 61:k:1,5,(7) was isolated from the affected testis. To the authors' knowledge, this is the first report of infection of the testis and epididymis by Salmonella in rams. This organism must be taken into account in the differential diagnosis of ovine genital infections.