Phylogenetic positioning of Listeria ivanovii identified in aborted sheep in Kars Region (Turkey)

Abstract

This study aimed to investigate Listeria species in various samples taken from aborted sheep in Kars province and to determine the position of emerged strains in the phylogenetic tree. Milk (n= 229) and vaginal swab (n= 263) samples from aborted sheep and abomasum contents (n= 46) of aborted sheep fetuses were investigated by the culture and Polymerase Chain Reaction (PCR) methods. For the phylogenetic analysis of isolates, the 16S rRNA gene region was sequenced. In the culture, the Listeria agent was not isolated from any of the vaginal swabs or milk samples. Among the 46 fetal abomasum contents, a Listeria suspicious colony was obtained from only one (2.17%) sample which belonged to an enterprise with a history of silage feeding. This isolate was identified as Listeria ivanovii by both conventional methods and genus and species-specific PCR. In addition, Listeria DNA was detected in a total of 8 (1.48%) samples (in 1 vaginal swab, 1 milk and 6 fetal abomasum samples) by direct genus-specific PCR. However, these samples could not be identified, except for one of the 6 abomasum content samples that was found as L. ivanovii. The L. ivanovii isolate was double-identified after the amplification of the 16S rRNA gene region followed by sequence analysis. Sequence analysis of the 16S rRNA gene region gave a phylogenetic position to the isolate, L. ivanovii, which had been scarcely identified from the abortive specimens.