Campylobacter fetus is a venereal pathogen of cattle and sheep, and an opportunistic human pathogen. It is often assumed that C. fetus infection occurs in humans as a zoonosis through food chain transmission. Here we show that mammalian C. fetus consists of distinct evolutionary lineages, primarily associated with either human or bovine hosts. We use whole-genome phylogenetics on 182 strains from 17 countries to provide evidence that C. fetus may have originated in humans around 10,500 years ago and may have “jumped” into cattle during the livestock domestication period. We detect C. fetus genomes in 8% of healthy human fecal metagenomes, where the human-associated lineages are the dominant type (78%). Thus, our work suggests that C. fetus is an unappreciated human intestinal pathobiont likely spread by human to human transmission. This genome-based evolutionary framework will facilitate C. fetus epidemiology research and the development of improved molecular diagnostics and prevention schemes for this neglected pathogen.

BackgroundBovine venereal campylobacteriosis is caused by Campylobacter fetus subsp. venerealis and its glycerine-tolerant variant Campylobacter fetus subsp. venerealis biovars intermedius. The disease can be economically important when present in cattle herds, causing poor reproductive performance, embryo mortality and abortion. Sensitive and specific diagnostic tests are required in the diagnosis of infection and to inform and monitor disease control. Current tests include bacterial culture and fluorescent antibody testing of preputial sheath washings and an enzyme-linked immunosorbent assay and an agglutination test on vaginal mucus, although the predictive values of these tests can be inadequate in field investigations.Artificial insemination is often considered as a simple control method for bovine venereal campylobacteriosis, but is impractical for many beef suckler herds where breeding takes place at pasture. Commercial vaccines are unavailable in the UK, while the efficacy of autogenous vaccines using a bacterial isolate from infected animals on a specific farm is at best unproven. Hence, for some infected herds, the development of an alternative control strategy based on segregation of potentially infected and uninfected animals in combination with culling or treatment would be desirable. This approach requires meticulous records and herd health management.Case presentationIn this paper we highlight difficulties in diagnosing bovine venereal campylobacteriosis and demonstrate the benefits of good record keeping when investigating poor reproductive performance in a beef suckler herd and establishing a herd-specific approach to bio-containment of the infectious cause.ConclusionsBovine venereal campylobacteriosis is an economically important disease that should be considered in investigations of suckler herd subfertility problems. Control of the disease based on segregation of potentially infected and uninfected animals in combination with extensive culling can be achieved without the use of artificial insemination or vaccination, but requires meticulous records and strict adherence to herd biosecurity practices.

Background: Making a clinical diagnosis of pericarditis in cattle is difficult and additional diagnostic tests are needed to evaluate cattle with suspected pericarditis. Serum cardiac troponin I (cTnI) concentrations are increased in cattle with pericarditis, but the utility of measuring serum cTnI concentrations in cattle with suspected pericarditis in cattle remains unclear.Objectives: To determine if serum cTnI concentrations in cattle can be used to differentiate pericarditis from other cardiac disorders and noncardiac thoracic diseases.Animals: Seventy‐seven clinically diseased cattle and 19 healthy control cattle.Methods: Serum cTnI concentrations were measured using an Immunlite Troponin I immunometric chemiluminescent assay in consecutive cases of postmortem‐confirmed pericarditis (n = 18), endocarditis (n = 15), chronic suppurative pneumonia (n = 13), congenital heart disease (n = 10), reticulitis (n = 3), mediastinal abscess (n = 7), thymic lymphoma (n = 6), and caudal vena cava thrombosis (n = 5). Serum cTnI concentrations were measured in 19 healthy cattle.Results: Although serum cTnI concentrations were significantly higher in cattle with pericarditis compared with healthy cattle, they were not significantly different from concentrations in cattle with endocarditis, congenital cardiac disease, mediastinal abscess, reticulitis, caudal vena cava thrombosis, or chronic suppurative pneumonia.Conclusions: Serum cTnI cannot be used to distinguish cattle with pericarditis from cattle with other primary cardiac diseases. In addition, serum cTnI concentrations cannot distinguish between cattle with primary cardiac diseases and those with other noncardiac, intrathoracic disorders.

Bull breeding soundness evaluation (BBSE) is commonly undertaken to identify bulls that are potentially unfit for use as breeding sires. Various studies worldwide have found that approximately 20% of the bulls fail their routine prebreeding BBSE and are therefore considered subfertile. Multiple articles describe the use of testicular ultrasound as a noninvasive aid in the identification of specific testicular and epididymal lesions. Two previous studies have hypothesized a correlation between ultrasonographic testicular parenchymal pixel intensity (PI) and semen quality; however to date, no published studies have specifically examined this link. The aim of this study, therefore, was to assess the relationship between testicular parenchymal PI (measured using trans-scrotal ultrasonography) and semen quality (measured at BBSE), and the usefulness of testicular ultrasonography as an aid in predicting future fertility in bulls, in particular those that are deemed subfertile at the first examination. A total of 162 bulls from 35 farms in the South East of Scotland were submitted to routine BBSE and testicular ultrasonography between March and May 2014, and March and May 2015. Thirty-three animals failed their initial examination (BBSE1) due to poor semen quality, and were re-examined (BBSE2) 6 to 8 weeks later. Computer-aided image analysis and gross visual lesion scoring were performed on all ultrasonograms, and results were compared to semen quality at BBSE1 and BBSE2. The PI measurements were practical and repeatable in a field setting, and although the results of this study did not highlight any biological correlation between semen quality at BBSE1 or BBSE2 and testicular PI, it did identify that gross visual lesion scoring of testicular images is comparable to computer analysis of PI (P < 0.001) in identifying animals suffering from gross testicular fibrosis.