Interaction of Mycobacterium avium subsp. paratuberculosis with bovine sperm
Jéssica Lobo Albuquerque Caldeira1, Ana Carolina Silva Faria1, Edgar Andres Diaz-Miranda2
1Department of Veterinary, Division of Preventive Medicine and Public Health, Universidade Federal de Viçosa, University Campus, PH Rolfs Avenue, 36570-000, Vicosa, Minas Gerais, Brazil.
Abstract:
Mycobacterium avium subsp. paratuberculosis (MAP) is responsible for Paratuberculosis mainly affecting domestic ruminants. The interaction between MAP and sperm and/or germ cells has not yet been established, however the adherence between MAP and the host cell surface is associated to the 85 complex proteins that bind to the host cell's fibronectin. Therefore, this study aimed to evaluate the binding of MAP to bovine sperm and to verify changes in these cells by the presence of MAP before and after sperm cryopreservation. Polyclonal antibodies to MAP 85 complex proteins were produced and utilized in the analyzes. Two Nelore bulls were used for semen collection and MAP dilutions (103-108 CFU/mL) were inoculated in the samples; sperm motility and vigor were evaluated using light microscopy at different times before and after cryopreservation and in the presence and absence of the antibodies 85A and 85B. Interaction of MAP and sperm, interaction of MAP and sperm in the presence of Ab 85A and in the presence of Ab 85B were analyzed by scanning electron microscopy. The viability of MAP after sperm cryopreservation were evaluated by plating the samples after thawing. It was observed that sperm in the presence of MAP shows a decrease in motility and vigor, and that the higher the MAP concentration, the lower the sperm performance. It was possible to determine the viability of MAP after cryopreservation in samples of higher concentrations, which demonstrates the potential of transmission of this pathogen through artificial insemination. The interaction of MAP with bovine sperm occurs mainly in the midpiece and may be linked to the proteins 85A and 85B present in the MAP membrane.
Insights
Mycobacterium avium subsp. paratuberculosis (MAP) can bind to bovine sperm, reducing motility and vigor. This interaction, potentially mediated by MAP 85 complex proteins, highlights risks for pathogen transmission via artificial insemination.
Area of Science:
- Veterinary Microbiology
- Reproductive Biology
- Bovine Infectious Diseases
Background:
- Mycobacterium avium subsp. paratuberculosis (MAP) causes Paratuberculosis in ruminants.
- The interaction between MAP and bovine germ cells is not well understood.
- MAP adherence to host cells involves 85 complex proteins binding to fibronectin.
Purpose of the Study:
- To investigate MAP binding to bovine sperm.
- To assess alterations in sperm quality due to MAP presence before and after cryopreservation.
- To explore the role of MAP 85 complex proteins in this interaction.
Main Methods:
- Production of polyclonal antibodies against MAP 85 complex proteins.
- Inoculation of bovine semen with varying MAP concentrations (10^3-10^8 CFU/mL).
- Evaluation of sperm motility and vigor via light microscopy; scanning electron microscopy for interaction analysis; MAP viability assessment post-cryopreservation.
Main Results:
- MAP presence significantly decreased sperm motility and vigor, with higher concentrations causing greater impairment.
- MAP was viable after sperm cryopreservation at higher concentrations.
- Scanning electron microscopy revealed MAP interaction with bovine sperm, primarily at the midpiece.
Conclusions:
- MAP can bind to bovine sperm, negatively impacting sperm quality.
- The 85A and 85B proteins of MAP may mediate sperm-pathogen interaction.
- Cryopreservation does not eliminate MAP in semen, indicating a risk of transmission through artificial insemination.
