molecular detection of listeria spp. in bovine aborted samples referred to the centerof excellence in ruminant abortion and neonatal mortality in iran

Listeria, a gram-positive pathogenic bacteria, mainly affects ruminants and humans, causinglisteriosis. it is not considered contagious and primarily occurs sporadically in winter andearly spring. clinical signs in ruminants include septicemia in neonates, meningoencephalitis(circling disease), and abortion in adults. listeria monocytogenes and listeria ivanovii areidentified as pathogens of warm-blooded hosts among the eight known species of listeria.in this study, a pcr method was used to detect listeria spp. in 100 cases of bovine abortedsamples. these samples were referred to the center of excellence in ruminant abortion andneonatal mortality at ferdowsi university of mashhad, iran, between 2022 and 2023. thesample was taken by placing the fetus on its left side. an incision was made in the skin andabdominal muscles on the right flank to obtain a liver sample. dna was extracted from thesamples. initially, all the samples were tested using the listeria genus-specific pcr primer.then, the samples in which the presence of listeria spp. was confirmed, were re-evaluatedusing specific primers of l. monocytogenes and l. ivanovii. out of the total of 117 examinedsamples, 1 (1%) sample was positive in bacterial culture and 1(1%) sample was declaredpositive in pcr. listeriosis is a zoonosis disease that causes abortion and subclinical diseasein humans. dairy cattle are usually a reservoir for bacteria. the significance of this study liesin its use of the molecular method (pcr) to analyze the rate of bovine abortion caused bylisteria. this method offers higher accuracy compared to bacterial culture, making thefindings more reliable and impactful.