Abstract: This invention is directed to compositions and methods for treating (e.g., prophylactically and/or therapeutically) infection in a preterm infant. In particular, the invention provides anti-lipoteichoic acid (LTA) antibody compositions and methods of administering the same to a preterm infant (e.g., a low birth weight preterm infant (e.g., a very low birth weight preterm infant)) under conditions to establish anti-LTA antibody serum concentrations effective to kill and/or prevent growth of bacteria (e.g., Staphylococci). Compositions and methods of the invention find use in, among other things, clinical (e.g. therapeutic and preventative medicine) and research applications.