Researchers are one step closer to slowing the spread of Enterococcus faecalis in poultry hatcheries with the discovery of a potential virulence factor.
About E. faecalis
E. faecalis is a gram-positive bacterium that is part of the normal microbiota of the intestinal tract of poultry, as well as other animals. It is typically one of the first species to colonize the intestines of chicks after hatching.
Even though E. faecalis is endemic in poultry, the gram-positive bacteria can cause disease if a chicken’s immune system is weakened. It is also thought to be responsible for reduced hatchability rates because of its presence in dead embryos and infertile eggs.
“E. faecalis is commonly picked up in the hatchery environment because they use incubators which are favorable for incubating eggs, but also bacteria,” explained Don Reynolds, professor, Veterinary and Biomedical Sciences, University of Nebraska-Lincoln.
One of the major challenges in treating E. faecalis it that it is antimicrobial resistant.
Mass spectrometry and the virulence factor
The researchers used a new mass spectrometry tool called Matrix-Assisted Laser Desorption/Ionization - Time of Flight Mass Spectroscopy (MALDI-TOF MS) to try to identify virulent from nonvirulent E. faecalis isolates.
The goal was to determine biomarkers that “distinguish between the good bugs and the bad bugs,” Reynolds said.
Mass spectroscopy converts samples, in this case E. faecalis, into ions and then separates ions based on their mass to charge ration using electric and magnetic fields. Once the technology is taught the difference between virulent and less virulent strains, it can identify and predict the degree of infection in unidentified samples.
“We found that we could distinguish the highly virulent strains from the very low or avirulent strains and we could do it with a high level of confidence. The problem came with all the strains in between,” said Reynolds.
The approach also confirmed the presence of a virulence factor called cytolysin that can introduce hemolysis – where red blood cells break down and release their contents into the surrounding fluid.
