The never-ending battle between lactic acid bacteria and their phages

Abstract

Over the past few decades, the interest in lactic acid bacteria (LAB) has been steadily growing. This is mainly due to their industrial use, their health benefits as probiotic bacteria and their ecological importance in host-related microbiota. Phage infection represents a significant risk for the production and industrial use of LAB. This created the need to study the various means of defense put in place by LAB to resist their viral enemies, as well as the countermeasures evolved by phages to overcome these defenses. In this review, we discuss defense systems that LAB employ to resist phage infections. We also describe how phages counter these mechanisms through diverse and sophisticated strategies. Furthermore, we discuss the way phage-host interactions shape each other's evolution. The recent discovery of numerous novel defense systems in other bacteria promises a new dawn for phage research in LAB.

HEPN-AbiV is an RNase in the antiphage system AbiV

“…A multitude of bacterial defense mechanisms collectively known as Abi have been discovered in various Gram-positive and Gram-negative bacteria, particularly in Lactococcus and E. coli. For example, over 20 types of Abi systems, named from AbiA to AbiZ based on their timing of discovery and characteristics, have been identified on plasmids and genomes of various Lactococcus strains (14). Most of the identified lactococcal Abi systems consist of a single gene, except for a few of them that encode multiple genes such as AbiE (15), AbiG (16), AbiL (17), AbiT (18), and AbiU (19).…”