title: Association of Histophilus somni with spontaneous abortions in dairy cattle herds from Brazil.
abstract: This study investigated the participation of infectious agents in spontaneous abortions and reproductive problems at eight dairy cattle herds from three geographical regions of Brazil. Fourteen aborted fetuses and the organ sections of one cow with history of repeated abortions were received for pathological evaluations and molecular diagnostics. PCR/RT-PCR assays targeted specific genes of abortifacient agents of cattle: bovine viral diarrhea virus (BVDV), bovine herpesvirus 1 (BoHV-1), Listeria monocytogenes, Neospora caninum, Leptospira spp., Brucella abortus, and Histophilus somni. Six fetuses were adequate for pathological investigations; one of these did not demonstrate remarkable pathological alterations. Significant histopathological findings included vasculitis, hemorrhage, and fibrinous thrombosis of the cerebrum (n = 4); necrotizing myocarditis (n = 3); and hemorrhagic enteritis (n = 3). The placenta and uterus of the cow as well as the kidney, pancreas, and liver of her aborted fetus contained H. somni DNA and demonstrated histopathological evidence of histophilosis. All fetuses contained H. somni DNA in multiple organs. Coinfections of H. somni with B. abortus (n = 2), N. caninum (n = 2), BVDV (n = 1), and BoHV-1 (n = 1) were identified; two fetuses demonstrated three pathogens. These findings suggest that H. somni was associated with the spontaneous abortions and reproductive problems of these herds. However, the exact cause of fetal death might not be attributed only to H. somni in all aborted fetuses, since some of these were infected with other abortifacient agents.
authors.affiliation: Laboratory of Animal Pathology, Department of Veterinary Preventive Medicine, Universidade Estadual de Londrina, Rodovia Celso Garcia Cid, PR 445 Km 380, Campus Universitário, P.O. Box 10.011, 86057-970, Londrina, Paraná, Brazil, selwyn.headley@uel.br.
authors.forename: Selwyn Arlington
authors.initials: SA
authors.lastname: Headley
authors.forename: Daniele
authors.initials: D
authors.lastname: Voltarelli
authors.forename: Victor Henrique Silva
authors.initials: VH
authors.lastname: de Oliveira
authors.forename: Dalton Evert
authors.initials: DE
authors.lastname: Bronkhorst
authors.forename: Alice Fernandes
authors.initials: AF
authors.lastname: Alfieri
authors.forename: Luiz Carlos Negri
authors.initials: LC
authors.lastname: Filho
authors.forename: Werner
authors.initials: W
authors.lastname: Okano
authors.forename: Amauri Alcindo
authors.initials: AA
authors.lastname: Alfieri
mesh_terms: D000034:Abortion, Veterinary / Q000382:microbiology*; D000818:Animals; D001938:Brazil / Q000453:epidemiology; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology*; D004269:DNA, Bacterial / Q000032:analysis; D003612:Dairying; D005260:Female; D006192:Haemophilus Infections / Q000453:epidemiology / Q000662:veterinary*; D044138:Haemophilus somnus / Q000235:genetics / Q000302:isolation & purification*; D018688:Neospora; D016133:Polymerase Chain Reaction / Q000662:veterinary; D011247:Pregnancy
chemical_list: D004269:DNA, Bacterial