Plasmid-directed mechanisms for bacteriophage defense in lactic streptococci

Use of bacteriophage-derived peptides to delay phage infections

“…Culture strains are rotated daily or when specific phage infections are detected (Cogan & Accoulas, 1990;Heap & Lawrence, 1976;Sing & Klaenhammer, 1993). Techniques using gene transfer for generating resistant starter strains have also been reported (Boucher, Emond, Parrot, & Moineau, 2001;Jarvis, 1981Jarvis, , 1978Jarvis & Klaenhammer, 1986;Klaenhammer, 1987;Klaenhammer & Sanozky, 1985;McLandsborough, Sechaud, & McKay, 1998;Sing & Klaenhammer, 1993).…”

Genetic Engineering of Bacteria Used in Food Fermentation

“…In general, bacteria have a variety of phage-defense systems that interfere with all steps of phage development -from phage adsorption to DNA injection and replication, expression of the phage genes, and assembly and maturing of the phage particle. Research into phage-resistance mechanisms of dairy starter strains and, especially, of lactococci, has been summarized recently in several comprehensive reviews (Klaenhammer, 1987;Hill, 1993;Forde and Fitzgerald, 1999;Coffey and Ross, 2002;Josephsen and Neve, 2004). In lactococci, the phage-defense systems are predominately encoded on plasmids, many of which are self-transmissible, and this affords the opportunity to transfer phage-resistance genes to other, industrially important strains by con jugation, a natural (food-grade) gene-transfer mechanism.…”

Genetics and Biotechnology of Lactic Acid Bacteria

“…Indeed, numerous lactococcal strains have been shown to contain two or more RIM systems of different specificity. The presence of multiple RIM systems of different specificity can dramatically increase the level of restriction elicited against incoming heterologous phages (Klaenhammer, 1987). Genetic studies have confirmed the natural occurrence of two or three RIM systems within a single strain (Sanders and Klaenhammer, 1980;Gautier and Chopin, 1987;Josephsen and Govensen, 1989).…”

“…Evidence for the involvement of plasmid DNA in the restriction and modification activities of lactococci was initially reported in Lactococcus cremoris KH (Sanders and Klaenhammer, 1981). Genetic studies with the lactococci have now established that their RIM activities are commonly encoded by plasmid DNA elements, some of which are self transmissible (for reviews see Klaenhammer, 1987;Chopin and Chopin, 1990). The common association of RIM systems with plasm ids in lactococci has contributed to:…”