Detection of Mycoplasma DNA Using Conventional Polymerase Chain Reaction in Canine Abortion, Stillbirth, and Neonatal Mortality Cases in Central Italy

Abstract

Mycoplasma spp. has been involved in canine infertility, but research on this topic is limited and shows conflicting results, as it has also been isolated from vaginal swabs of healthy dogs. This study aimed to retrospectively research Mycoplasma DNA by a conventional dual Polymerase Chain Reaction from 114 cases of canine abortion, stillbirth, and neonatal mortality that occurred in Central Italy. In addition, four fetal membranes from dystocic dams were analyzed. In total, 7 out of 114 cases (6.14%) and one of the fetal membranes tested positive for Mycoplasma DNA. From five of them (62.5%), other microorganisms were identified, particularly Canid herpesvirus-1 (2/8, 25%) and Escherichia coli, Staphylococcus aureus, and/or Staphylococcus pseudintermedius (3/8, 37.5%), notoriously responsible for infertility in bitches or neonatal mortality. In two different litters, only one puppy of each one tested positive for Mycoplasma DNA. Additionally, Mycoplasma DNA was detected in fetal membranes collected during a cesarean section of a bitch whelping Mycoplasma-negative puppies, supporting that Mycoplasma spp. is part of the normal genital microflora of the female. The detection of Mycoplasma DNA in association with other major pathogens and its detection in the female genital tract without transmission to puppies support the hypothesis that Mycoplasma belongs to the autochthonous genital microflora or, at most, may play a secondary role in canine abortion and neonatal mortality.

Keywords: Mycoplasma spp.; abortion; dog; neonatal mortality; sequencing.