In Vitro Interaction between Mycoplasma agalactiae and Small Ruminants' Endogenous Bacterial Strains of Enterococcus spp. and Coagulase-Negative Staphylococcus
Related Experiment Video
Updated: Jun 20, 2026
A Murine Model of Group B Streptococcus Vaginal Colonization
Published on: November 16, 2016
Marion Toquet1, Esther Bataller1, Raquel Toledo-Perona1
1Microbiological Agents Associated with Animal Reproduction (ProVaginBIO) Research Group, Departamento Producción y Sanidad Animal, Salud Pública Veterinaria y Ciencia y Tecnología de los Alimentos, Facultad de Veterinaria, Universidad Cardenal Herrera-CEU, CEU Universities, Carrer Tirant lo Blanc, 7, 46115 Valencia, Spain.
Abstract:
Recently, an antimicrobial effect on Mycoplasma agalactiae (Ma), the main etiological agent of contagious agalactia (CA), was reported in vitro with strains of Enterococcus spp. from ovine and caprine milk. The aim of this work was to evaluate the interaction of Ma with the same Enterococcus spp. isolated from other anatomical locations (vagina) and other bacterial populations present in milk, such as coagulase-negative staphylococci (CNS). The vaginal Enterococcus strains and the raw milk CNS were isolated from sheep and goats. Experimental in vitro conditions were prepared to assess the growth of Ma with and without the presence of these strains. The selected vaginal strains were identified as Enterococcus (E.) hirae and E. mundtii, and the strains of CNS were identified as Staphylococcus petrasii. Different interactions of Ma with ovine and caprine wild vaginal strains of Enterococcus and dairy strains of CNS are described for the first time: Ma can grow exponentially during 15 h with the selected strains, although with certain strains, its optimal growth can be negatively affected (p < 0.05). The colonization and/or excretion of Ma could, therefore, be influenced by certain endogenous bacterial strains. Our results increase the knowledge about possible bacterial ecology dynamics surrounding CA.
Insights
This study explored how vaginal Enterococcus and milk coagulase-negative staphylococci affect Mycoplasma agalactiae (Ma) growth. Certain bacteria can inhibit Ma, influencing contagious agalactia (CA) dynamics.
Area of Science:
- Veterinary Microbiology
- Bacterial Ecology
- Animal Infectious Diseases
Background:
- Mycoplasma agalactiae (Ma) causes contagious agalactia (CA) in small ruminants.
- Previous studies showed Enterococcus spp. from milk inhibit Ma in vitro.
- The role of Enterococcus from other body sites and other milk bacteria on Ma growth is less understood.
Purpose of the Study:
- To investigate the in vitro interaction between Ma and Enterococcus spp. from the vaginal tract.
- To assess Ma's interaction with coagulase-negative staphylococci (CNS) from raw milk.
- To understand the influence of endogenous bacteria on Ma colonization and excretion.
Main Methods:
- Isolation of vaginal Enterococcus and milk CNS from sheep and goats.
- Identification of selected vaginal Enterococcus strains as E. hirae and E. mundtii.
- Identification of CNS strains as Staphylococcus petrasii.
- In vitro co-culture experiments to monitor Ma growth with and without the presence of selected bacterial strains.
Main Results:
- Ma exhibited exponential growth for up to 15 hours in the presence of selected vaginal Enterococcus and milk CNS strains.
- The optimal growth of Ma was negatively affected (p < 0.05) by certain tested bacterial strains.
- This study provides the first description of Ma interactions with ovine and caprine wild vaginal Enterococcus and dairy CNS strains.
Conclusions:
- Endogenous bacterial populations, including vaginal Enterococcus and milk CNS, can influence the growth and potentially the colonization/excretion of Mycoplasma agalactiae.
- These findings contribute to understanding the complex bacterial ecology surrounding contagious agalactia.
- Further research into these interactions could inform novel strategies for managing CA.
