Microbial diseases of the genital system of rams or bucks

Lesions of the prepuce and penis in rams: A retrospective study

In the ovine reproductive management, a thorough breeding soundness evaluation including specific inspection of the male genital tract represents a valuable tool for assessing the reproductive potential of a selected subject and for diagnosing genital disorders. During examination, accurate inspection on penis and prepuce is necessary, since conditions affecting these structures may hamper regular coitus. Records from 1270 males undergoing breeding soundness evaluation (n = 1232) or admitted for genital disorders to the Section of Obstetrics and Gynaecology (n = 38) of the Department of Veterinary Medicine, were collected, and lesions of penis and prepuce were therefore classified. The data collected revealed that 47/1270 rams examined presented lesions of the penis and prepuce. The most frequent condition was urolithiasis accounting for over 2% of the cases, followed by lack of the urethral process (0.39% incidence), lack of the glans penis and hypospadias (0.23% cases). Moreover, most of the conditions (40%) were observed in animals less than 2 years old, suggesting the importance of a careful breeding soundness evaluation in animals at young age.

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.

Reproductive Management of Rams and Ram Lambs during the Pre-Breeding Season in US Sheep Farms

In sheep farms, achieving economic and productive efficiency and sustainability goals is directly related with the reproductive management of the animals. Genetically, the male contribution to the offspring is 50%, but in practical terms, there is a greater potential impact of the ram on reproductive results, because one male has the potential to affect a large group of females and therefore greatly affects the entire flock. Unfortunately, the selection of males for breeding in the US sheep industry has been traditionally conducted based on phenotypical traits, without a genetic/reproductive evaluation, and/or health assessment or records. Therefore, it is important to establish integrative management practices to select the rams and ram lambs to be used in the breeding season. Among these practices are genomic testing, a comprehensive breeding soundness evaluation and assessment of health status and records of the males before the breeding season, to detect and correct potential issues.

Brucella ovis Cysteine Biosynthesis Contributes to Peroxide Stress Survival and Fitness in the Intracellular Niche

Brucella ovis is an ovine intracellular pathogen with tropism for the male genital tract. To establish and maintain infection, B. ovis must survive stressful conditions inside host cells, including low pH, nutrient limitation, and reactive oxygen species. The same conditions are often encountered in axenic cultures during stationary phase. Studies of stationary phase may thus inform our understanding of Brucella infection biology, yet the genes and pathways that are important in Brucella stationary-phase physiology remain poorly defined. We measured fitness of a barcoded pool of B. ovis Tn-himar mutants as a function of growth phase and identified cysE as a determinant of fitness in stationary phase. CysE catalyzes the first step in cysteine biosynthesis from serine, and we provide genetic evidence that two related enzymes, CysK1 and CysK2, function redundantly to catalyze cysteine synthesis at steps downstream of CysE. Deleting cysE (ΔcysE) or both cysK1 and cysK2 (ΔcysK1 ΔcysK2) results in premature entry into stationary phase, reduced culture yield, and sensitivity to exogenous hydrogen peroxide. These phenotypes can be chemically complemented by cysteine or glutathione. ΔcysE and ΔcysK1 ΔcysK2 strains have no defect in host cell entry in vitro but have significantly diminished intracellular fitness between 2 and 24 h postinfection. Our study has uncovered unexpected redundancy at the CysK step of cysteine biosynthesis in B. ovis and demonstrates that cysteine anabolism is a determinant of peroxide stress survival and fitness in the intracellular niche.

Research Relevant Background Lesions and Conditions: Ferrets, Dogs, Swine, Sheep, and Goats

Animal models provide a valuable tool and resource for biomedical researchers as they investigate biological processes, disease pathogenesis, novel therapies, and toxicologic studies. Interpretation of animal model data requires knowledge not only of the processes/diseases being studied but also awareness of spontaneous conditions and background lesions in the model that can influence or even confound the study results. Species, breed/stock, sex, age, anatomy, physiology, diseases (noninfectious and infectious), and neoplastic processes are model features that can impact the results as well as study interpretation. Here, we review these features in several common laboratory animal species, including ferret, dog (beagle), pig, sheep, and goats.

Management of Reproductive Diseases in Male Small Ruminants

Reproductive tract diseases can be a significant cause of subfertility or infertility in male small ruminants. Affected males can usually be identified early by performing routine serologic screening and yearly breeding soundness examinations. Early diagnosis will either maximize treatment success or expedite culling decisions. Once clinical signs of diseases develop, prognosis for breeding ability declines. Veterinary practitioners should used ancillary diagnostic techniques, such as ultrasound examination and laboratory testing to acquire a diagnosis and determine prognosis of reproductive lesions. Some diseases (eg, brucellosis) should be ruled out immediately to cull affected animals and minimize transmission within the herd.

Actinobacillus seminis GroEL-homologous protein agglutinates sheep erythrocytes

Actinobacillus seminis, a commensal of ovine and caprine reproductive organs, is able to induce epididymitis in the small ruminants that it infects. In this work, we characterised two protein bands of approximately 150 kDa and 65 kDa. These proteins cross-reacted with a polyclonal serum against Gallibacterium anatis hemagglutinin and with a polyclonal serum from sheep with epididymitis, indicating that the proteins are expressed in vivo; the two proteins also interacted with biotin-labeled sheep fibrinogen and fibronectin, suggesting that they may function as adhesins. The participation of these proteins as adhesins was confirmed by a cultured human bladder cell-A. seminis adhesion assay and adherence inhibition by preincubation of A. seminis with polyclonal antiserum to the 150 kDa protein. Both proteins presented sequence identity with an A. seminis GroEL protein by mass spectrometry analysis and agglutinated glutaraldehyde-fixed sheep red blood cells. Immunogold labeling was observed by transmission electron microscopy on bacterial cells that were negatively stained, and a peroxidase reaction was detected in A. seminis biofilms, when an anti-A. seminis 150 kDa protein serum was used, indicating the presence of this protein on the surface of A. seminis and in biofilms. The A. seminis GroEL-homologue is a multifunctional protein that likely acts as a hemagglutinin.

Scrotal enlargement in rams and bucks in Qassim region, central of Saudi Arabia: clinical and ultrasonographic findings and seroprevalence of brucellosis

The aim of this study was to clarify the causes of scrotal enlargement in rams and bucks in Qassim region of Saudi Arabia. Enlarged scrotal contents of rams and bucks (n = 153) were examined by visual inspection, palpation, and ultrasonography. Blood samples were obtained and tested for Brucella sp. infection. Clinical and ultrasonographic findings showed that scrotal enlargement was mainly associated with orchitis, peri-orchitis, and epididymitis. Miscellaneous findings were scrotal hernia, scrotal hematoma, and hydrocele. The frequencies of orchitis, peri-orchitis, and epididymitis were 47.4, 21.1, and 14.1% in Awassi rams; 54.5, 21.7, and 8.7% in Najdi rams; 52.3, 20.5, and 9.1% in Ardi bucks; and 50, 16.7, and 16.7% in Damascus bucks, respectively. Orchitis was associated with no-abscess formation (23%), single-abscess formation (15.4%), and multiple-abscesses formation (61.6%). Peri-orchitis was characterized by hard consistency, atrophy of the testes, and extensive connective tissue formation. Epididymitis was observed mainly at the tail of the epididymis (82.4%) but rarely at the head (17.6%). Epididymitis was associated in many cases with abscessation (70.6%). Males with orchitis, peri-orchitis, and epididymitis were positive for Brucella melitensis and Brucella ovis in the frequency of 21.3% and 48.8%, respectively. In conclusion, scrotal enlargement in rams and bucks in Qassim region is caused mainly by inflammation of the testis and/or epididymis and associated tremendously with brucellosis seropositivity.