Lysis of Streptococci by an Extracellular Lysin Produced by Competent Group H Streptococcus Strain CHALLIS

Ranhand, Jon M.; Cole, Roger M.

doi:10.1099/00221287-71-1-199

Cited by 12 publications

(7 citation statements)

References 7 publications

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“…The purification of CF from filtrates has been attempted by several authors (3,4,9,14). The presence of different factors in the filtrates affecting the CF activity complicates the purification (1, 1 5 , 16,17). It seems important to destroy the CFI activity by heating before its inactivation of CF.…”

Section: Discussionmentioning

confidence: 99%

GENETIC TRANSFORMATION IN STREPTOCOCCUS SANGUIS

Gaustad

1981

Acta Pathologica Microbiologica Scandinavica Section B Microbio

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Genetic transformation in Streptococcus sanguis is a complex, multi‐step process, involving several factors. The competence factor (CF), occurring in the culture filtrates of some strains, is essential in streptococcal transformation, but other factors are also involved. The presence of serum during growth is not obligatory for the preparation of active culture filtrate, but serum increases the amount and duration of CF activity of some strains. The stability of the CF activity differs distinctly in filtrates prepared from various strains. This observation can be explained by the presence of a previously undescribed factor — named the competence factor inactivator (CFI) — which inactivates the CF in culture filtrates during the transforming experiment as well as during storage. The CFI is thermolabile and is eliminated from the filtrates by heating (65 °C for 15 min). The properties of the CFI suggest that it may be a protein with enzymatic activity. The CFs from the strains Challis and 13b resist heating to 100 °C for 2 h, and are stable for at least 72 h if the CFI is absent or has been inactivated by heating. The CF activity in the filtrates is inactivated by pronase and chymotrypsin, suggesting that the CF may be of a polypeptide nature.

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Section: Discussionmentioning

confidence: 99%

GENETIC TRANSFORMATION IN STREPTOCOCCUS SANGUIS

Gaustad

1981

Acta Pathologica Microbiologica Scandinavica Section B Microbio

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“…The other 9.0 ml of culture was chilled on ice until all samples were collected. CF was heated to inactivate the lytic activity that is present in such preparations (8).…”

Section: Methodsmentioning

confidence: 99%

Autolytic Activity and Its Association with the Development of Competence in Group H Streptococci

Ranhand

1973

J Bacteriol

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Seventeen strains of group H streptococci were tested for their ability to develop competence for genetic transformation, either spontaneously or with the addition of competence factor derived from strain Challis supernatant fluids, and for their ability to autolyze. Autolysis was measured as a decline in optical density after washed cells were placed in a buffer at pH 9. Kinetic experiments showed that, in strains Challis, SBE I/II, WE4, SR 30, and a strain (FW 227) cured of its bacteriophage, competence and the ability to autolyze occurred simultaneously. Since autolysis was observed only in (i) competent cells, (ii) cells that passed their peak of competence, and (iii) those cells that exhibit a potential for developing competence but never go on to transform (i.e., lysogenized Challis cells), it is concluded that, in the group H streptococci, autolytic events are associated with the competent state. Strains that transformed but did not autolyze were not found. These strains are further described in references 4 and 5. Strain SR 30 was obtained from D. Perry, Northwestern University, Chicago, Ill. (7). An erythromycin-resistant Wicky strain (WE4), derived in this laboratory, was described previously (11). Cultures of Challis and SBE I/lI, in our collection, were originally obtained from H. Slade, Northwestern University, Chicago, Ill. Growth and maintenance of cultures. All cultures were grown in brain-heart infusion (BH broth; Difco) supplemented with 2.5% heat-inactivated (56 C, 30 min) horse serum (BH-HS broth; Microbiological Associates) and maintained at-40 C, or on sheep blood-tryptose agar (Difco) slants at 4 C. Kinetics of spontaneous competence development. Starting with a 5% (vol/vol) inoculum, cells

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“…Participation of other factors in the transforma-I93 tion has been reported ( I , 2, 12,13,141, and these factors may influence the efficiency of transformation, but their presence is not obligatory for the transformation process.…”

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confidence: 99%

GENETIC TRANSFORMATION IN STREPTOCOCCUS SANGUIS

Gaustad

1983

Acta Pathologica Microbiologica Scandinavica Series B: Microbio

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The production and the persistence of competence factor (CF) and competence factor inactivator (CFI) of four different strains of Streptococcus sanguis in three media (Todd Hewitt broth, medium II and medium IV) have been examined with respect to kinetics. Both the medium used and the strains examined offered implications on the activities of CF and CFI. CF was not detectable in the culture filtrates of strains Wicky (NCTC 9124) and 445. Strain Blackburn (NCTC 10231) showed activity only in Todd Hewitt broth and strain 14567 in Todd Hewitt broth and medium IV. The activity persisted for 2 to 7 hours during exponential growth. In culture filtrates of the strains Wicky and Blackburn the three media yielded high CFI activity persisting during the entire growth period. The strains 445 and 14567 were less potent CFI producers in medium II and medium IV, and no CFI was detected in the culture filtrates from Todd Hewitt broth. Medium II was the most suitable medium for CFI production and seems appropriate for further studies and isolation of the factor. In medium IV no strain had CF activity. This medium was supplemented with serum, albumin, tyrosine or glutamic acid, and CF and CFI production and persistence by strain 14567 were studied in relation to growth phases. CF and CFI activities were observed in the different supplemented media during short periods of growth, but could not be related to any given phase of growth. The presence of CFI in a culture eliminated or reduced the CF activity, and a specific interaction of CF and CFI was observed. The CFI from the strain Wicky inactivated CF from the strains Challis (NCTC 7868) and Blackburn, but not from the strains 13b and 14567. The CFI from the strains 445 and 14567 reduced the activity of CF produced by the strains 13b and 14567, but not CF from the strains Challis and Blackburn.

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Lysis of Streptococci by an Extracellular Lysin Produced by Competent Group H Streptococcus Strain CHALLIS

Cited by 12 publications

References 7 publications

GENETIC TRANSFORMATION IN STREPTOCOCCUS SANGUIS

GENETIC TRANSFORMATION IN STREPTOCOCCUS SANGUIS

Autolytic Activity and Its Association with the Development of Competence in Group H Streptococci

GENETIC TRANSFORMATION IN STREPTOCOCCUS SANGUIS

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