Isolation of Lactococcal Prolate Phage-Phage Recombinants by an Enrichment Strategy Reveals Two Novel Host Range Determinants

Rakonjac, Jasna; O’Toole, Paul W.; Lubbers, Mark W.

doi:10.1128/jb.187.9.3110-3121.2005

Cited by 12 publications

(9 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In view of this, we concluded that despite the resistance of L. lactis strain IL-1403 to c2 infection, initial phage binding to the cell surface was preserved, while the subsequent stage of phage development was blocked. A similar observation was reported for other c2-like bacteriophages (43). This result can be explained by the mechanisms of host cell infection by such phages.…”

Section: Discussionsupporting

confidence: 74%

Fluorescence Correlation Spectroscopy To Study Diffusion and Reaction of Bacteriophages inside Biofilms

Briandet

Lacroix-Gueu

Renault

et al. 2008

Appl Environ Microbiol

138

View full text Add to dashboard Cite

In the natural environment, most of the phages that target bacteria are thought to exist in biofilm ecosystems. The purpose of this study was to gain a clearer understanding of the reactivity of these viral particles when they come into contact with bacteria embedded in biofilms. Experimentally, we quantified lactococcal c2 phage diffusion and reaction through model biofilms using in situ fluorescence correlation spectroscopy with two-photon excitation. Correlation curves for fluorescently labeled c2 phage in nonreacting Stenotrophomonas maltophilia biofilms indicated that extracellular polymeric substances did not provide significant resistance to phage penetration and diffusion, even though penetration and diffusion were sometimes restricted because of the noncontractile tail of the viral particle. Fluctuations in the fluorescence intensity of the labeled phage were detected throughout the thickness of biofilms formed by c2-sensitive and c2-resistant strains of Lactococcus lactis but could never be correlated with time, revealing that the phage was immobile. This finding confirmed that recognition binding receptors for the viral particles were present on the resistant bacterial cell wall. Taken together, our results suggest that biofilms may act as "active" phage reservoirs that can entrap and amplify viral particles and protect them from harsh environments.

show abstract

Section: Discussionsupporting

confidence: 74%

Fluorescence Correlation Spectroscopy To Study Diffusion and Reaction of Bacteriophages inside Biofilms

Briandet

Lacroix-Gueu

Renault

et al. 2008

Appl Environ Microbiol

138

View full text Add to dashboard Cite

show abstract

“…ORF26 shares similarity with several c2-like phage tail proteins, and the best match was with the tape measure protein (ORFl10) of phage c2 (34% identity; 193/ 567). Other matches included the industrial lactococcal phage isolates 5469 (35% identity; 180/507) and 5440 (28% identity; 148/528) (64). ORF26 was also found in the structure of Q54 as revealed by SDS-PAGE and mass spectrometry analyses (Fig.…”

Section: Resultsmentioning

confidence: 99%

Genome Sequence and Global Gene Expression of Q54, a New Phage Species Linking the 936 and c2 Phage Species ofLactococcus lactis

2006

View full text Add to dashboard Cite

The lytic lactococcal phage Q54 was previously isolated from a failed sour cream production. Its complete genomic sequence (26,537 bp) is reported here, and the analysis indicated that it represents a new Lactococcus lactis phage species. A striking feature of phage Q54 is the low level of similarity of its proteome (47 open reading frames) with proteins in databases. A global gene expression study confirmed the presence of two early gene modules in Q54. The unusual configuration of these modules, combined with results of comparative analysis with other lactococcal phage genomes, suggests that one of these modules was acquired through recombination events between c2-and 936-like phages. Proteolytic cleavage and cross-linking of the major capsid protein were demonstrated through structural protein analyses. A programmed translational frameshift between the major tail protein (MTP) and the receptor-binding protein (RBP) was also discovered. A "shifty stop" signal followed by putative secondary structures is likely involved in frameshifting. To our knowledge, this is only the second report of translational frameshifting (؉1) in double-stranded DNA bacteriophages and the first case of translational coupling between an MTP and an RBP. Thus, phage Q54 represents a fascinating member of a new species with unusual characteristics that brings new insights into lactococcal phage evolution.Lactococcus lactis is a low-GϩC gram-positive bacterium extensively used by the dairy industry for its ability to convert sugars into lactic acid, leading to various fermented milk products. However, L. lactis strains are susceptible to attacks by lytic bacteriophages with concomitant low-quality products and economic losses (56). Different strategies have been developed over the past 70 years with the aim of better controlling the indigenous phage population within the dairy environment (54, 71). Nevertheless, the phage population is constantly evolving and new phage isolates are still frequently isolated. Some of these phages are emerging due to current manufacturing practices (49).Classification of the phages is still controversial, and different propositions have been made in recent years (10,65,74). Previous classification studies relied on the comparison of virus morphology and DNA-DNA hybridizations using whole genomes. According to these criteria, 12 lactococcal phage species representing distinct phage groups were proposed (37, 38). This classification of lactococcal phages was recently revisited, and 10 genetically diverse groups of phages, sharing very limited nucleotide similarities, were proposed (26). Among these, two new species were identified, one of which was the type phage Q54.Phage genomics has considerably expanded in the last 5 years, and as of June 2006, 362 complete genomes are available at GenBank. Of those, 14 are from lactococcal phages. Among the available genomes, only members of the three main groups of L. lactis phages are represented, namely, the 936, c2, and P335 species. Ten of the genomes are from phage...

show abstract

“…This is in agreement with the results of the lysogenic conversion assay, which verified that TP901-1C efficiently lysogenizes L. lactis UC509.9. Recently, it was reported by Rakonjac et al (40) that the acquirement of a new sequence adjacent to the cosR site in L. lactis phage c2 could overcome a host infection inhibition mechanism acting on the level of DNA injection or circularization by cos-end ligation. The corresponding pac site of TP901-1 is expected to be located in the vicinity of the late promoter (7), i.e., within the secondary recombination of TP901-1C.…”

Section: Discussionmentioning

confidence: 99%

Identification of the Lower Baseplate Protein as the Antireceptor of the Temperate Lactococcal Bacteriophages TP901-1 and Tuc2009

et al. 2006

View full text Add to dashboard Cite

The first step in the infection process of tailed phages is recognition and binding to the host receptor. This interaction is mediated by the phage antireceptor located in the distal tail structure. The temperate Lactococcus lactis phage TP901-1 belongs to the P335 species of the Siphoviridae family, which also includes the related phage Tuc2009. The distal tail structure of TP901-1 is well characterized and contains a double-disk baseplate and a central tail fiber. The structural tail proteins of TP901-1 and Tuc2009 are highly similar, but the phages have different host ranges and must therefore encode different antireceptors. In order to identify the antireceptors of TP901-1 and Tuc2009, a chimeric phage was generated in which the gene encoding the TP901-1 lower baseplate protein (bppL TP901 The first physical contact between a phage and its bacterial host is a crucial step in the life cycle of the phage. For tailed phages, this initial host interaction is mediated by a so-called antireceptor located in the distal part of the tail. This antireceptor recognizes and interacts with a specific structure or receptor on the surface of the host cell as a prerequisite to the injection of the phage genome. In several Escherichia coli phages, e.g., , P2, T4, and the T-even-type phages, the phage antireceptors have been identified in tail fibers (20,26,48). In contrast to this, the antireceptors of the E. coli phages T5 and BF23 have been shown to be located in the tail shaft just above a straight tail fiber (22,24). Compared to these extensively studied E. coli phages, the knowledge of the antireceptors of phages infecting lactic acid bacteria (LAB), and gram-positive bacteria in general, is limited. Most speculations regarding genes encoding host-interacting proteins of LAB phages originate from sequence comparisons among the rapidly increasing number of completely sequenced LAB phages (10,11,31,33,39). Phage antireceptor proteins of a few Streptococcus thermophilus and Lactococcus lactis phages have, however, recently been identified. Duplessis and Moineau (12) identified ORF18 as the determinant of host specificity for the S. thermophilus phages DT1 and MD4 by the generation of chimeric phages with an altered host range. These chimeric phages were readily propagated on the new host strain, and a C-terminal variable region of orf18 was found to be responsible for host recognition. In similar studies, Stuer-Lauridsen et al. (44) and Dupont et al. (14) identified receptor binding proteins of the virulent L. lactis phages bIL67 and CHL92 of the c2 species and sk1 and bIL170 of the 936 species, respectively. The chimeric phages in those studies displayed an altered host range in plaque assays, but the phages were either partially or completely deficient in their ability to propagate lytically on the new host strain, thus indicating that additional factors may contribute to the host range determination of these phages. Although the receptor binding protein from sk1 was shown to be located at the tip of the phage tail (14)...

show abstract

Isolation of Lactococcal Prolate Phage-Phage Recombinants by an Enrichment Strategy Reveals Two Novel Host Range Determinants

Cited by 12 publications

References 58 publications

Fluorescence Correlation Spectroscopy To Study Diffusion and Reaction of Bacteriophages inside Biofilms

Fluorescence Correlation Spectroscopy To Study Diffusion and Reaction of Bacteriophages inside Biofilms

Genome Sequence and Global Gene Expression of Q54, a New Phage Species Linking the 936 and c2 Phage Species ofLactococcus lactis

Identification of the Lower Baseplate Protein as the Antireceptor of the Temperate Lactococcal Bacteriophages TP901-1 and Tuc2009

Contact Info

Product

Resources

About