Microbiological, molecular, and histopathological findings in goats experimentally infected with Actinobacillus seminis.

The objective of this study was to experimentally evaluate the pathogenicity of an Actinobacillus seminis isolate named SAAS01 in goats. Animals were challenged with 2 mL of a suspension containing 1,5 × 108 CFU/mL of A. seminis (SAAS01 isolate) through the intrapreputial, epididymis tail, and conjunctival routes. Epididymis and testicular fragments were submitted to histopathological exam, and semen samples underwent microbiological and molecular diagnoses. Clinically, a unilateral increase in firm consistency was observed in the epididymis and testicles of two animals inoculated in epididymis tail and in one animal inoculated through conjunctival sac; this firmness continued until the day of euthanasia. Two goats inoculated through epididymis tail and conjunctival sac routes presented histopathological findings with macroscopically and microscopically significant changes. A. seminis was isolated from semen samples collected from goats inoculated through the epididymis tail and conjunctival sac routes. A. seminis DNA was amplified from six semen samples of three goats inoculated through the epididymis tail, two in conjunctival sac and one through intrapreputial route. The experimental infection model using goats confirmed the pathogenicity of the A. seminis isolate, demonstrating the predilection of the agent for the epididymis, with clinical signs, histopathological lesions, bacterial isolation, and a positive molecular diagnosis.

Isolation of Actinobacillus seminis from a goat with clinical epididymo-orchitis in Brazil.

The present study reports the first isolation of Actinobacillus seminis from a goat in Brazil. A four-year-old Moxotó breeding goat in a flock of 70 goats and 65 sheep reared together in the county of Patos, semiarid region of Northeastern Brazil, showed clinical signs of unilateral orchitis and epididymitis. Diagnosis of A. seminis infection was confirmed by association of clinical findings, bacterial isolation and 16S rRNA gene sequencing. This result suggests that A. seminis may be an additional cause of infertility in goats, and that sheep may be the source of infection because the mixed farming system allows the contact between sheep and goats in the semiarid region of Northeastern Brazil.

Isolation of Actinobacillus seminis from a goat with clinical epididymo-orchitis in Brazil

The present study reports the first isolation of Actinobacillus seminis from a goat in Brazil. A four-year-old Moxotó breeding goat in a flock of 70 goats and 65 sheep reared together in the county of Patos, semiarid region of Northeastern Brazil, showed clinical signs of unilateral orchitis and epididymitis. Diagnosis of A. seminis infection was confirmed by association of clinical findings, bacterial isolation and 16S rRNA gene sequencing. This result suggests that A. seminis may be an additional cause of infertility in goats, and that sheep may be the source of infection because the mixed farming system allows the contact between sheep and goats in the semiarid region of Northeastern Brazil.

Epididimite ovina por Actinobacillus seminis no Estado de Pernambuco / Sheep epididymitis by Actinobacillus seminis in the state of Pernambuco, Brazil

Relata-se a ocorrência de orquite e epididimite ovina associada ao isolamento de Actinobacillus seminis no Estado de Pernambuco. Clinicamente observou-se aumento de volume nos testículos e epidídimos, dor e aumento de temperatura local à palpação, e atrofia testicular bilateral. Após o abate observou-se a presença de conteúdo purulento no epidídimo. À microscopia dos testículos observou-se espessamento da túnica albugínea, necrose de coagulação e calcificação de túbulos seminíferos, infiltrado inflamatório com predominância de linfócitos entre túbulos seminíferos, além de mineralização incipiente de túbulos. No epidídimo observou-se intensa proliferação de tecido conjuntivo ao redor dos ductos epididimários. O diagnóstico de orquite e epididimite por Actinobacillus seminis foi confirmado pela associação dos achados clínico-patológicos, isolamento e identificação da bactéria.

This study reports the occurrence of sheep epididymitis and the isolation of Actinobacillus seminis in the state of Pernambuco, Brazil. An increase in volume of the testicles and epididymis, pain and increase in the local temperature at palpation, and bilateral testicular atrophy were clinically observed. After slaughter, the presence of purulent content in the epididymis was found. In microscopy of the testicles, coagulation necrosis and calcification of seminiferous tubules, thickening of the tunica albuginea, fibrosis, inflammatory infiltrate with predominance of lymphocytes between seminiferous tubules and incipient mineralization of tubules was observed. In the epididymis, intense proliferation of conjunctive tissue and fibrosis around the epididymal ducts was found. The diagnosis of epididymitis by Actinobacillus seminis was confirmed with association of the clinical findings, isolation and identification of the bacteria, as well as through histopathological exam.

Pathological changes in accessory sex organs of rams following experimental infection with Actinobacillus seminis.

AIM: To investigate and assess the susceptibility, lesions and route of dissemination in the accessory sex organs of young rams experimentally infected with Actinobacillus seminis. METHODS: The accessory sex organs were obtained from 64 young rams. The test rams (n=52) were infected by instillation, drenching or injection of 2.3 x 10(9) cells/ml A. seminis organisms via nine different routes: intra-epididymal (1 ml), I/V (3 ml), intra-urethral (3 ml), intra-preputial (3 ml), ductus deferens (1 ml), I/M (3 ml), oral (10 ml), intranasal (3 ml), and intra-conjunctival (3 drops). All test rams were necropsied 1-44 days post-inoculation (p.i.). Control rams (n=12) were necropsied at 1-46 days p.i. Accessory sex organs were cultured for A. seminis, and thin tissue sections were collected and examined for histopathological changes. RESULTS: Vesicular adenitis was the most frequent lesion (21/52; 40%), followed by ampullitis, deferentitis, urethritis and bulbo-urethral adenitis (20/52 (38%), 16/52 (31%), 12/52 (23%), and 8/52 (15%), respectively). The prostate and prepuce were the least affected, and lesions occurred equally at 4% (2/52). Actinobacillus seminis was isolated from the accessory sex organs of 10 (19%) rams: from the vesicular glands (n=6), ductus deferens (n=3), ampullae (n=1), and prepuce (n=3). No lesions were seen in rams inoculated via the nasal and conjunctival routes. The pattern of involvement of both ascending and descending A. seminis infection of the genital tract is discussed. CONCLUSIONS: Involvement of the accessory sex organ of rams following all but the intranasal and intra-conjunctival routes of the nine routes of experimental inoculation tested helped to clarify the epidemiology, pathogenesis, and pathology of ovine genital actinobacillosis.

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.

Identification of an immunogenic protein of Actinobacillus seminis that is present in microvesicles.

Actinobacillus seminis is a gram-negative bacterium of the Pasteurellaceae family that is involved in ovine epididymitis. Looking for a protein specific to this species, we determined the protein profile of subcellular fractions of A. seminis (American Type Culture Collection number 15768): proteins from the outer membrane (OMPs), inner membrane (IMPs), and cytoplasm (CPs). These profiles provide the first data, to our knowledge, regarding subcellular fractions of A. seminis. In the OMP fraction, we identified a protein with a molecular mass of 75 kDa that proved to be immunogenic and apparently specific for A. seminis. This conclusion was based on the reaction of hyperimmune serum of rabbits inoculated with whole cells of A. seminis that was tested against sonicated complete cells of reference strains and field isolates of Brucella ovis, Mannheimia haemolytica, Pasteurella multocida, and Histophilus somni. No protein of these bacteria cross-reacted with the 75-kDa protein of A. seminis. Furthermore, when each type of hyperimmune serum was tested against the sonicated cells and each of the subcellular fractions of A. seminis, it did not recognize the A. seminis 75-kDa protein. We also isolated and identified this protein in microvesicles released to the culture supernatant. The results suggest that the 75-kDa protein could be used to establish a diagnostic test specific for ovine epididymitis caused by A. seminis.