The isolation of mycoplasma from bovine foetuses and their dams

Role of Infection and Immunity in Bovine Perinatal Mortality: Part 1. Causes and Current Diagnostic Approaches

While non-infectious causes are more commonly diagnosed in cases of bovine perinatal mortality (PM), the proportion caused by infections is highly variable between studies (~5-35%); the reasons for this variation, and possible underestimation, are discussed. The most important pathogen-specific infectious causes of PM are bacteria (in particular, Bacillus licheniformis and Leptospira spp.), viruses (in particular BVDv) and a parasite (Neospora caninum). However, co-infection may occur in a small proportion of cases and in many cases no single pathogen is detected but gross or microscopic lesions of an inflammatory response are identified. Diagnosis is complicated by the criteria required to establish exposure, infection and causation. Additionally, pathogens can be classified as primary or secondary though such differentiation can be arbitrary. The majority of infectious cases of PM are due to in utero infections but postnatal infections (0-2 days) can also cause PM. Diagnosis of infectious PM is based on a systematic investigation of the herd health history and dam and cohort sampling and examination of the perinate and its placenta. Gross and histopathologic examinations and maternal/herd and perinate serology form the basis of current infectious PM investigations.

Bovine abortion and neonatal death associated with Ureaplasma diversum

Ureaplasma diversum was isolated from the lungs and/or stomach fluid and placentas of five aborted bovine fetuses and four newborn calves. All isolates were serotype D48. Placentitis was observed in all instances in which the placenta was examined. Gross lesions consisted of focal or diffuse reddening of the chorioallantois and amnion and thickening of the amnion. Microscopically there were fibrosis, edema and inflammation of the amnion. Microscopic lesions in the lung consisted of diffuse pneumonitis with thickening of the alveolar walls and in some cases peribronchiolar lymphoid accumulations. Macrophages and granulocytes were present in the alveoli. Inoculation of the vulva of a virgin heifer with one of the isolates from a fetal lung produced hyperemia and profuse purulent discharge with slight granularity.

An aetiopathological study of chronic bronchopneumonia in lambs in Ireland

Chronic bronchopneumonia in lambs, also known as 'atypical' or 'chronic, non-progressive' pneumonia is a common, frequently sub-clinical disease affecting animals under 12-months-old in intensive production systems. Infection with both Mycoplasma ovipneumoniae and Mannheimia haemolytica have been implicated in the aetiology of this condition and a variety of pulmonary lesions can result. In this study, detailed laboratory examination of 30 abattoir-derived lungs with the characteristic gross features of atypical pneumonia (AP) was carried out with a view to refining and correlating the histopathological and microbiological criteria required for the diagnosis of this disease. For the first time a broad range of laboratory detection techniques including bacterial and virus isolation, fluorescent antibody tests and immunohistochemistry were used in parallel to identify potential causative pathogens such as M. ovipneumoniae, M. haemolytica, parainfluenza type-3 (PI3) virus and respiratory syncytial virus (RSV) in AP lesions. The most consistent finding was the association of gross AP lesions with M. ovipneumoniae, identified by either culture or immunohistochemistry in 27 (90%) of the 30 cases. However the presence M. ovipneumoniae organisms or antigen did not consistently correlate with particular histopathological changes. Furthermore, peri-airway lymphoid hyperplasia, intra-alveolar exudation and nodular 'hyaline scars', which are all previously reported microscopic lesions of AP, were not identified in 12 (40%) of the cases and isolation of M. haemolytica was over-represented in lungs exhibiting suppurative lesions. These findings illustrate the complex aetiopathogenesis of this disease and highlight the requirement to use a combination of diagnostic criteria in its laboratory diagnosis.

Isolation of mycoplasma species from the lower respiratory tract of healthy cattle and cattle with respiratory disease in Belgium

Between 1997 and 2000, a total of 150 healthy cattle and 238 animals with respiratory disease were examined for six Mycoplasma species. Attempts were made to detect Mycoplasma canis, Mycoplasma dispar and Ureaplasma diversum in calves with recurrent disease, and all three of these species were identified in calves with recurrent disease and in healthy lungs. In healthy calves, 84 per cent of bronchoalveolar lavage fluids were mycoplasma free; when cultures were positive, Mycoplasma bovirhinis was the only species isolated. Mycoplasmas were isolated from 78 per cent of animals suffering recurrent respiratory disease and from 65 per cent of acute respiratory cases. Mycoplasma bovis was isolated from bronchoalveolar lavages from 35 per cent of calves suffering recurrent respiratory disease, and from 50 per cent of acute cases, and from 20 per cent of pneumonic cases examined postmortem. M bovis was associated with other Mycoplasma species in 44 per cent of cases. M dispar was also isolated from 45.5 per cent of calves suffering recurrent respiratory disease, often in association with M bovis. M canis was identified for the first time in diseased Belgian cattle. Other mycoplasmas, including Mycoplasma arginini, Mycoplasma alkalescens and U diversum, were isolated less frequently. Associations between mycoplasmas and other pathogens were often observed. Among lungs infected with Pasteurella and/or Mannheimia species, more than 50 per cent were mixed infections with M bovis.

Effect of fetal mass, number and stage of gestation on pregnancy-specific protein B concentrations in the bovine

In this study we characterized the peripheral plasma pregnancy-specific protein-B (PSPB) profile throughout gestation and examined the effect of stage of gestation, fetal mass and number on this profile in Holstein cows after non surgical embryo transfer. Cows (n = 12) were divided into 2 groups: Group 1 = single embryo recipient cows (n = 5), Group 2 = twin-embryo recipient cows (n = 7). Blood was collected approximately every third day from Day 0 (Day 0 = first day of standing estrus), then daily for the last 10 d of gestation, and sampling was stopped 1 d post partum. Two twin-embryo recipient cows had abnormal pregnancies; therefore, their data were excluded from the group. The time trend concentrations of plasma PSPB were significantly affected by the stage of gestation (P < 0.001) and fetal number (P < 0.001). In both groups PSPB increased gradually, with the mean levels being significantly higher (P < 0.01) in the twin-bearing group from Day 50 onwards (0.7 +/- 0.2 vs 9.2 +/- 4.5 ng/ml, singleton and twin-bearing cows, respectively) except for Day 10 pre-partum. By mid-gestation (Day 140), mean PSPB levels increased in the singleton (P < 0.001) cows by thirty-fold (21.2 +/- 3.2 ng/ml) as opposed to a ten-fold (98.4 +/- 13.2 ng/ml) increase in the twin-bearing (P < 0.001) group. The mean PSPB concentrations between Days 30 to 20 prepartum dramatically increased by about 700 to 200% in singleton (128.8 +/- 46.3 to 745.6 +/- 66.7 ng/ml) and twin-bearing cows (375.6 +/- 130.4 to 861.5 +/- 127.9 ng/ml), respectively. The PSPB levels between Day 10 prepartum to parturition were significantly higher (P < 0.001) in the twin-bearing group than in the singleton group (745.6 +/- 66.7 to 1627.4 +/- 238.9 ng/ml vs 861.5 +/- 127.9 to 3103.0 +/- 643.0 ng/ml in singleton and twin-bearing groups, respectively). Calf birthweight was correlated (P < 0.01) to peripheral PSPB concentration in singleton cows; however, this relationship decreased with the subsequent increase in fetal number. Cows giving birth prematurely to stillborn calves or to a schistosomus reflexus calf exhibited abnormal PSPB profiles. These results indicate that peripheral PSPB levels are correlated to the stage of gestation and fetal number. In addition, the peripheral pattern of PSPB is a valuable guage for predicting fetoplacental viability.

Ureaplasma diversum as a cause of reproductive disease in cattle

This article includes a brief review of the classification, habitat, and characteristics of the ureaplasmas, followed by a discussion of the pathogenesis, transmission, clinical syndromes, diagnosis, immunity, and treatment of Ureaplasma diversum infections in cattle.