Bovine mycotic abortion in Denmark

A survey is given of the occurrence of mycotic infections associated with abortion in Danish cattle. During a period of six years a total of 748 samples of placenta material were examined. Mycotic abortion was demonstrated in 101 cases (14%). The case rate was significantly higher (21%) during the winter months from December through February than during the rest of the year (10%). Abortions occurred as from the 135th day of pregnancy, with maximum in the eighth month, where 45% of all cases were observed. A. fumigatus was demonstrated in 77 cases, Mucor spp. in 11 cases, Absidia spp. in 5 cases, and a mixed infection with A. fumigatus and Mucor spp. in 3 cases. In 5 cases the fungi were demonstrated by microscopic and histological examination, but not by culture. The annual occurrence of mycotic abortion varied from 10% to 24% of cases of abortion examined. The latter figure was recorded in a year following a particularly heavy rainfall in the month of June.     

Bovine mycotic abortion: some epidemiological aspects

Records from 898 cases of bovine mycotic abortion occurring over the five years 1969 to 1974 in South Wales were examined with particular reference to incidence and climate. Mean incidence was lowest in September and highest in January and February. Annual incidence of Aspergillus-type infection decreased but that of Mucortype did not alter significantly. Most abortions occurred during the last trimester of pregnancy. The abortion rate for cattle fed hay in cowsheds was extremely high compared with that for other management systems. No correlation could be detected between total rainfall or number of raindays in June and September and mycotic abortions occurring over the succeeding 12 months. Fungal abortion was followed by pregnancy in most cases where subsequent breeding performance was known.     

Bovine mycotic abortion--a comparative study of diagnostic methods

The agreement between three diagnostic methods (mycology, morphology, and immunofluorescence staining) was compared two by two in elucidating the aetiological diagnosis in 52 cases of bovine mycotic abortion. Agreement between the three methods was expressed by the kappa coefficient (kappa), and ranked as follows: mycology and immunofluorescence staining (kappa = 0.48); morphology and immunofluorescence staining (kappa = 0.40); mycology and morphology (kappa = 0.28). A. fumigatus was confirmed to be the main cause of bovine mycotic abortion with members of the zygomycetes (order Mucorales) being the second most important group. In two aborted placentas a Candida species was found to be the cause of mycotic placentitis.     

Bovine abortion caused by Bacillus cereus

Bacillus cereus was identified as an infrequent abortigenic agent in cattle. Necrotizing placentitis with no or sporadic lesions in fetal tissues was seen. Bacillus cereus was isolated in pure culture from fetal tissue and/or placenta. The recent identification of a bovine abortion caused by B cereus, prompted a retrospective survey of the pathology files. Eight of 947 bovine abortions were attributed to B cereus. Bacillus cereus is often mistaken as a contaminant in bovine abortion because of the failure to identify lesions in fetal tissues compatible with bacterial invasion. A necrotizing toxin may be responsible for the placentitis, with expulsion of the fetus before bacterial colonization.     

Aspergillus terreus as a cause of mycotic abortion in cows

The fungus Aspergillus terreus Thom et Church was subjected to microscopic and cultivation study in the organs of an aborted foetus and was demonstrated to be the causative agent of abortion in cattle. The culture of the isolated organism is described and brief data reporting on its ecology are presented. Attention is drawn to the probable source of infection and to the insufficiently known aspects of the pathogenesis of this disease.     

Bovine abortion and necrotic placentitis by Aspergillus terreus

A 31-month-old Japanese Black cow (Bos taurus) aborted at 5 months of gestation with no clinical symptoms. Histopathological examination of the placenta and fetus revealed severe necrotic placentitis associated with numerous irregular degenerative fungi and inflammatory cells. Regular filamentous fungi were also detected, without inflammatory response in the fetal digestive and respiratory organs. Both fungi had aleurioconidia and septa in the placenta and fetal organs and immunohistochemically stained with antibodies against Aspergillus spp. Aspergillus terreus was isolated from the fetal lung and abomasal contents as confirmed using mycological and molecular methods. This is the first immunohistochemical, morphological, and molecular identification of A. terreus in bovine placenta and aborted fetuses.