Testosterone and estradiol modify the expression of adhesins and biofilm formation in Actinobacillus seminis.

Actinobacillus seminis is the causal agent of epididymitis and has other effects on the reproductive tracts of small ruminants and bovines. This bacterium causes infection when luteinizing (LH) or follicle-stimulating hormones increase, and hosts reach sexual maturity. LH induces female ovulation and male testosterone production, suggesting that these hormones affect A. seminis pathogenicity. In the present study, we evaluated the effect of testosterone (1-5 ng/ml) or estradiol (5-25 pg/ml) added to culture medium on the in vitro growth, biofilm production, and adhesin expression of A. seminis. Estradiol does not promote the growth of this bacterium, whereas testosterone increased A. seminis planktonic growth 2-fold. Both hormones induced the expression of the elongation factor thermo unstable (EF-Tu) and phosphoglycerate mutase (PGM), proteins that A. seminis uses as adhesins. Estradiol (5 or 10 pg/ml) decreased biofilm formation by 32%, whereas testosterone, even at 5 ng/ml, showed no effect. Both hormones modified the concentrations of carbohydrates and eDNA in biofilms by 50%. Amyloid proteins are characterized by their capacity to bind Congo red (CR) dye. Actinobacillus seminis binds CR dye, and this binding increases in the presence of 5-20 pg/ml estradiol or 4 ng/ml testosterone. The A. seminis EF-Tu protein was identified as amyloid-like protein (ALP). The effect of sexual hormones on the growth and expression of virulence factors of A. seminis seems to be relevant for its colonization and permanence in the host.

Mannheimia haemolytica OmpH binds fibrinogen and fibronectin and participates in biofilm formation.

Mannheimia haemolytica is the causal agent of the shipping fever in bovines and produces high economic losses worldwide. This bacterium possesses different virulence attributes to achieve a successful infection. One of the main virulence factors expressed by a pathogen is through adhesion molecules; however, the components participating in this process are not totally known. The present work identified a M. haemolytica 41 kDa outer membrane protein (Omp) that participates in bacterial adhesion. This protein showed 100% identity with the OmpH from M. haemolytica as determined by mass spectrometry and it interacts with sheep fibrinogen. The 41 kDa M. haemolytica OmpH interacts with bovine monocytes; a previous incubation of M. haemolytica with a rabbit hyperimmune serum against this Omp diminished 45% cell adhesion. The OmpH was recognized by serum from bovines affected by acute or chronic pneumonia, indicating its in vivo expression; moreover, it showed immune cross-reaction with the serum of rabbit infected with Pasteurella multocida. The OmpH is present in biofilms and previous incubation of M. haemolytca with rabbit serum against this protein diminished biofilm, indicating this protein's participation in biofilm formation. M. haemolytica OmpH is proposed as a relevant immunogen in bovine pneumonia protection.

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.

Achados microbiológicos, moleculares e histopatológicos em pequenos ruminantes experimentalmente infectados com Actinobacillus seminis / Microbiological, molecular and histopathological findings in small ruminants experimentally infected with Actinobacillus seminis

O objetivo deste trabalho foi avaliar a patogenicidade, em ovinos, de uma cepa de Actinobacillus seminis isolada de caprino no Brasil. Foram utilizadas amostras de sêmen, punção e fragmentos de epidídimo, ducto deferente, testículos e glândulas seminíferas de dois caprinos (animais 1 e 2) e dois ovinos (animais 3 e 4), e foram realizados exame histopatológico, cultivo microbiológico e diagnóstico molecular. O inóculo foi preparado com solução salina na diluição de 10-2 correspondendo ao padrão 1,0 da escala de McFarland, com colônias previamente cultivadas de A. seminis e administrado no volume de 2 mL pelas vias intra-prepucial (animais 1 e 3) e na cauda do epidídimo (animais 2 e 4). Na avaliação clínica observou-se aumento unilateral de consistência firme após 30 dias no epidídimo e testículo do animal 4 que continuou até o dia da eutanásia, bem como o animal 1 apresentou discreto aumento unilateral dos testículos. As lesões macroscópicas e microscópicas observadas nos animais 3 e 4 foram compatíveis com aquelas causadas pela infecção por A. seminis. A. seminis foi isolado de material de punção e sêmen de um ovino (animal 4). Conclui-se que o modelo de infecção experimental utilizando caprinos e ovinos comprovou a patogenicidade da amostra de A. seminis, isolada de um caprino no semiárido brasileiro e reproduzida em um ovino, comprovando a predileção do agente pelo epidídimo, com quadro clinico, achados histopatológicos, isolamento bacteriano e diagnóstico molecular positivo.(AU)

The aim of this study was to evaluate, in sheep, the pathogenicity of an Actinobacillus seminis strain isolated from a goat in Brazil. Samples of semen, puncture and fragments of epididymis, deferent duct, testicles and seminal vesicles from two goats (animals 1 and 2) and two sheep (animals 3 and 4) were used, and histopathological, microbiological culture and molecular diagnoses were performed. The inoculum was prepared with saline solution at 10-2 dilution corresponding to 1.0 McFarland standard, with A. seminis colonies previously cultured and administered on 2mL volume by intra-preputial (animals 1 and 3) and epididymis tail (animals 2 and 4) routes. At clinical evaluation it were found unilateral swelling of firm consistency after 30 days in epididymis and testicle from animal 4 that continued until the day of euthanasia, as well as animal 1 shown discrete unilateral swelling of testicles. Gross and microscopic lesions in animals 3 and 4 were compatibles with that caused by A. seminis infection. A. seminis was isolated from material of puncture and semen of one sheep (animal 4). It is concluded that the experimental infection model using goats and sheep has proved the pathogenicity of the A. seminis strain isolated from a goat in the Brazilian semiarid and reproduced in a sheep, which confirm the prediletion of the agent for epididymis, with clinical signs, histopathological findings, bacterial isolation and positive molecular diagnosis.(AU)

Distribution of lymphocytes, immunoglobulin-containing cells, macrophages, and dendritic cells in the accessory sex glands of rams experimentally infected with actinobacillus seminis / Distribuição de linfócitos, células carreadoras de imunoglobulinas, macrófagos e células dendríticas em glândulas sexuais acessórias de carneiros infectados experimentalmente com actinobacillus seminis

The distribution of cells involved in the immune response in accessory sex glands of rams experimentally infected with Actinobacillus seminis was studied. Twelve one-year old rams were experimentally infected by intraurethral (IU) (n=4) and intraepididymal (IE) (n=4) route, and four control (CON) animals were used. The animals were slaughtered 35 days post-inoculation, samples were taken from accessory sex glands, and bacteriology and histopathology tests were performed. The presence of CD4, CD8 and TCRγδ (WC1) lymphocytes, CD45RO cells, macrophages (CD14), dendritic cells (CD1b), IgA-, IgG- and IgM-containing cells (IgCC) was determined. Animals of the IE group developed clinical epididymitis. No lesions were seen in rams of the IU group; two of the intraepididymal inoculated CON developed small lesions in the epididymis. A. seminis isolates were achieved from 6:16 (37.5%) accessory sex glands in the IE group, but not in the IU and CON groups. In the CON group, IgA- and IgM- containing cells predominated in the bulbourethral glands and the disseminated prostate, and they were scarce or null in the vesicles and ampullae. A significant increase of IgA-, IgG- and IgM- containing cells was confirmed in the seminal vesicles, the ampullae and the bulbourethral glands in the IE group. In the IE and IU groups, an increase in CD4, CD8, WC1, CD45RO and CD14 was evidenced in the vesicles and ampullae. CD1b dendritic cells were present in the ampullae and vesicles with inflammatory processes. A. seminis triggered a local immune response in the IE and IU groups. These results indicate a different pattern of infiltrating immune cells in the accessory sex glands of infected A. seminis rams.

A distribuição das células envolvidas na resposta imune em glândulas sexuais acessórias de carneiros experimentalmente infectados com Actinobacillus seminis foi estudada. Doze carneiros de um ano de idade foram experimentalmente infectados via intrauretral (IU) (n=4) e via intraepididimal (IE) (n=4) e quatro animais controles (CON) foram utilizados. Os animais foram abatidos 35 dias após a inoculação, amostras foram retiradas das glândulas sexuais acessórias e testes bacteriológicos e histopatológicos foram realizados. A presença de linfócitos CD4, CD8 e TCRγδ (WC1), células CD45RO, macrófagos (CD14), células dendríticas (CD1b) e células contendo IgA, IgG and IgM (IgCC) foi determinada. Os animais do grupo IE desenvolveram epididimite clínica. Não foram visualizadas lesões nos carneiros do grupo IU, dois dos CON inoculados intraepididimalmente desenvolveram pequenas lesões no epidídimo. Isolados de A. seminis foram obtidos de 6:16 (37,5%) nas glândulas sexuais acessórias no grupo IE mas não nos grupos IU e CON. No grupo CON células contendo IgA and IgM predominaram nas glândulas bulbouretrais e na próstata e foram escassas ou ausentes nas vesículas e na ampola. Um incremento significativo de células contendo IgA, IgG and IgM foi confirmado nas vesículas seminais, na ampola e nas glândulas bulbouretrais no grupo IE. Nos grupos IE e IU foi evidenciado um aumento em CD4, CD8, WC1, CD45RO e CD14 nas vesículas e ampola. As células dendríticas CD1b estavam presentes na ampola e nas vesículas com processo inflamatório. A. seminis induziu uma resposta imune local nos grupos IE e IU. Estes resultados indicam um padrão diferente de células imunes infiltrantes nas glândulas sexuais acessórias de carneiros infectados por A. seminis.

Microbial diseases of the genital system of rams or bucks.

Objective of the present paper is to review microbial diseases of the genital system of male small ruminants. The paper reviews the infections and the diseases by taking an organ approach within the genital system, whilst relevant health management actions are also discussed. Diseases of the genital organs of male small ruminants include orchitis, of bacterial or viral aetiology, epididymitis, primarily caused by Brucella ovis, by other bacteria as well (e.g., Actinobacillus seminis, Haemophilus somni), infections of the accessory glands, orf, other infections of the penis or prepuce and infections of the scrotum. The health management of rams/bucks include the appropriate diagnostic investigations, the relevant therapeutic approaches and, finally, the preventive measures.

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.