The bacterial recognition protein PGRP-SA has been studied extensively for its interaction with Gram-positive bacteria (e.g. Staphylococcus aureus, Streptococcus faecalis, Bacillus thuringiensis, Bacillus subtilis and Micrococcus luteus) upon infection, but its potential association with commensal bacteria has not been explored. Here, PGLYRP1 is linked to infection.