Submitted to: International Journal of Systematic and Evolutionary Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/25/2002
Publication Date: 11/1/2002
Citation: DONAHUE, J.M., WILLIAMS, N.M., SELLS, S.F., LABEDA, D.P. CROSSIELLA EQUI SP. NOV., ISOLATED FROM EQUINE PLACENTAS. INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY. 2002. V. 52. P. 2169-2173. Interpretive Summary: Over the past decade a new type of infection of the placenta in horses has been observed in Kentucky, and results in loss of the foal in approximately half of the cases. This type of infection has been fairly low in number, usually no more than 30 infected mares each year, but numbers of infected horses has been higher during recent years. A bacterium which grows as branching filaments has been isolated from the infected animals and was identified as a member of the genus Crossiella based on the sequence of its ribosomal RNA gene. A comparison of the physiological characteristics of the equine bacteria with the described species of Crossiella proved that they belong to a new species for which the name Crossiella equi is proposed. This formal description of Crossiella equi will be of great use to other scientists and veterinarians who are dealing with infections of the reproductive system in horses.
Technical Abstract: Over the course of the past decade, actinomycetes have been isolated from the placentas of horses diagnosed with nocardioform placentitis. The incidence of this infection has been generally low, with typically no more than 30 animals affected most years, but the incidence increased through 1999, with placentas from 144 mares found to be infected. Approximately half of the cases result in loss of the foal. A typical actinomycete with branching mycelium was isolated from placental lesions, and a search of the sequence of the 16S rDNA gene against the public databases indicated a relationship to members of the suborder Pseudonocardineae. Phylogenetic analysis of a number of isolates revealed a close relationship to Crossiella cryophila, and subsequent polyphasic comparisons determined that these isolates represent a new species of Crossiella, for which the name Crossiella equi is proposed, with C. equi NRRL B-24104**T as the type species.