Some properties ofStreptococcus thermophilus bacteriophages

Kivi, S.; Peltomäki, Timo; Luomala, Kirsti; Sarimo, Seppo S.

doi:10.1007/bf02883235

Cited by 19 publications

(10 citation statements)

References 20 publications

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“…As observed for all previously characterized S. thermophilus phages, the phages used in this work belonged to the Siphoviridae family (corresponding to group B as defined by Bradley [3]) and showed a clear tendency to aggregate into clusters (6,7,12,15). These phages have double-stranded DNA genomes whose sizes range from 30.7 to 42.7 kb, in accord with previous reports (1,6,7,17,22,25).…”

Section: Discussionsupporting

confidence: 85%

Detection and Characterization of Streptococcus thermophilus Bacteriophages by Use of the Antireceptor Gene Sequence

Binetti

Río

Martín

et al. 2005

Appl Environ Microbiol

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In the dairy industry, the characterization of Streptococcus thermophilus phage types is very important for the selection and use of efficient starter cultures. The aim of this study was to develop a characterization system useful in phage control programs in dairy plants. A comparative study of phages of different origins was initially performed based on their morphology, DNA restriction profiles, DNA homology, structural proteins, packaging mechanisms, and lifestyles and on the presence of a highly conserved DNA fragment of the replication module. However, these traditional criteria were of limited industrial value, mainly because there appeared to be no correlation between these variables and host ranges. We therefore developed a PCR method to amplify VR2, a variable region of the antireceptor gene, which allowed rapid detection of S. thermophilus phages and classification of these phages. This method has a significant advantage over other grouping criteria since our results suggest that there is a correlation between typing profiles and host ranges. This association could be valuable for the dairy industry by allowing a rational starter rotation system to be established and by helping in the selection of more suitable starter culture resistance mechanisms. The method described here is also a useful tool for phage detection, since specific PCR amplification was possible when phage-contaminated milk was used as a template (detection limit, 10 5 PFU ml ؊1 ).In the dairy environment, lytic phages are the leading cause of fermentation failure during the manufacture of cheese and fermented milk products. Consequently, the success of commercial lactic starter cultures depends primarily on the selection of non-phage-related strains able to withstand viral infections. Streptococcus thermophilus, a gram-positive thermophilic lactic acid bacterium, is a component of dairy starter cultures used for the manufacture of yogurt and other fermented milk products. As observed for other dairy lactic acid bacteria, this streptococcus is often susceptible to phage attack, which can result in slow lactic acid fermentation and the loss of product quality. Besides its use as a starter in the yogurt industry, this species is very important in the production of a large variety of cheeses (26), from which many S. thermophilus phages responsible for fermentation failure have recently been isolated (32). Since a large dairy plant can processes more than 5 ϫ 10 5 liters of milk per day, phage problems can be very costly. The economic implications have led to intensive research into methods to control bacteriophage infections in the industry. The traditional strategies used to minimize the consequences of phage infection include rotation of non-phage-related strains (the principal precautionary measure employed), the use of phageinhibiting media for culture propagation, and aseptic processing conditions (14). However, the effectiveness is sometimes limited by the dynamic evolutionary properties of phages (7,22) and, in the case of S. ther...

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Section: Discussionsupporting

confidence: 85%

Detection and Characterization of Streptococcus thermophilus Bacteriophages by Use of the Antireceptor Gene Sequence

Binetti

Río

Martín

et al. 2005

Appl Environ Microbiol

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“…In a study involving nine S. salivarius subsp. thermophilus phages isolated from Finnish cheese plants, Kivi et al (1987) observed that the electrophoretic profiles of the structural proteins appeared nearly identical. The molecular masses of the four major proteins were estimated to be 63,49, 42 and 11 kDa.…”

Section: Discussionmentioning

confidence: 95%

Close Relationship of Virulent Bacteriophages of Streptococcus salivarius subsp. thermophilus at Both the Protein and the DNA Level

et al. 1989

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Comparisons of 23 virulent phages of Streptococcus salivarius subsp. thermophilus were made based on morphology, host-range, structural protein analysis, DNA restriction patterns and DNA homology. All the phages had isometric heads (diameters 55-58 nm) and striated tails (lengths 221-275 nm). The genome sizes ranged from 37 to 43 kb. The electrophoretic profiles of the structural proteins were related, with at least two major bands of about 23 and 29 kDa in common for all the phages except three, $80, $96 and $99. These latter phages, which had a particular protein composition (main proteins of 29 and 40 kDa) and high DNA homology between each other, showed only a low DNA homology with the other phages. Extensive DNA homologies were demonstrated by Southern hybridization for all the other phages. All these results suggest a close evolutionary relationship between the phages.

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“…Conversely, Iittle is known about phages and phage-resistance mechanisms in S salivarius subsp thermophilus. Studies based on the host range, structurai proteins, serological and morphological properties were carried out (Kivi et al, 1987). The effect of incubation temperature on the development of S salivarius subsp thermophilus and its phages was studied (Sozzi et al, 1978).…”

Section: Introductionmentioning

confidence: 99%

Genetic and biological characterization of nine Streptococcus salivarius subsp thermophilus bacteriophages

Larbi

Colmin

Rousselle

et al. 1990

Lait

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Summary -Nine bacteriophages of Streptococcus salivarius subsp thermophilus isolated from different fermentation accidents, with different geographic origins, were compared according to their genomic structures and growth characteristics. Their genomes are linear, double-stranded DNA, with complementary cohesive ends. They belong to one group and are c1assed into 2 closely related strains. The phages of the same strain show the same restriction pattern with BamHI, EcoRI, Hindlll and Pvu II. The bacteriophages <1>81.2 and A 1.1 representative of the strain 1 and strain 2 respectively were characterized and compared according to their morphology, growth characteristics, restriction maps and DNA homology. They belong to Bradley's group B. The optimum concentration of 25 mM was determined for phage infections requiring calcium ions. One-step growth studies show that the latent period is 25 min for both A1.1and B1.2;their burst size is 88 and 56 particles per infected cell, respectively. Their genomes are 36.2 ± 0.5 and 35.6 ± 0.5 kbp in length, respectively.The restriction maps of these genomes are constructed. Cross-hybridization experiments showed that the 2 bacteriophages are clossly related. Using Southern blot hybridization, no homology was detected between the DNA of various bacterial strains, te, strains sensitive or resistant to phage infections, and the B1.2DNA, indicating that these bacteria are not Iysogenic for these phages.

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Some properties ofStreptococcus thermophilus bacteriophages

Cited by 19 publications

References 20 publications

Detection and Characterization of Streptococcus thermophilus Bacteriophages by Use of the Antireceptor Gene Sequence

Detection and Characterization of Streptococcus thermophilus Bacteriophages by Use of the Antireceptor Gene Sequence

Close Relationship of Virulent Bacteriophages of Streptococcus salivarius subsp. thermophilus at Both the Protein and the DNA Level

Genetic and biological characterization of nine Streptococcus salivarius subsp thermophilus bacteriophages

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