In vivo depletion of CD4+CD25+ regulatory T cells in cats.

To establish a characterized model of regulatory T cell (Treg) depletion in the cat we assessed the kinetics of depletion and rebound in peripheral and central lymphoid compartments after treatment with anti-CD25 antibody as determined by cell surface markers and FOXP3 mRNA expression. An 82% decrease in circulating CD4+CD25+ Tregs was observed by day 11 after treatment. CD4+CD25+ cells were also reduced in the thymus (69%), secondary lymphoid tissues (66%), and gut (67%).

Plasmid-specified FemABX-like immunity factor in Staphylococcus sciuri DD 4747.

A plasmid from Staphylococcus sciuri DD 4747 had three open reading frames: a replication gene, an N-acetylmuramyl-l-alanine amidase-like gene, and a gene similar to the lysostaphin endopeptidase resistance gene (epr/lif). The epr-like gene was introduced into S. aureus RN4220; the recombinant strain was more resistant to lysostaphin endopeptidase and its cell wall peptidoglycan contained more serines and fewer glycines than the parental strain with the shuttle vector alone.

The streptococcolytic enzyme zoocin A is a penicillin-binding protein.

Zoocin A is a streptococcolytic enzyme produced by Streptococcus equi subsp. zooepidemicus 4881 that has an unknown site of action on the peptidoglycans of susceptible organisms. Analysis of a mutant strain in which the genes for zoocin A and resistance to zoocin A were inactivated revealed that this strain was more susceptible to beta-lactam antibiotics than the parental organism.