On the Nature of Competence of Transformable Streptococci

R, Pakula; Walczak, W.

doi:10.1099/00221287-31-1-125

Cited by 200 publications

(115 citation statements)

References 4 publications

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“…Group H streptococcus strain Challis is capable of producing the competence factor (CF) as well as performing bacterial transformation, while strain Wicky in the same group is incapable of CF production but changes to a competent and transformable phase upon addition of Challis CF (6). We have observed inhibition of the growth of Wicky cells when they are exposed to the CF.…”

mentioning

confidence: 70%

Group H Streptococcal Bacteriocins Having No Relation to Bacterial Transformation

Ito

1982

Microbiology and Immunology

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The culture filtrate of group H streptococcus strain Challis produced a competence factor (CF) for bacterial transformation as well as a bactericidal factor(s) against Wicky cells. Strain 36658, in the same streptococcal group, also produced the bactericidal factor(s) but not CF. The effect of the Challis bacteriocin was limited to strains Wicky and 58, whereas the 36658 bacteriocin affected 67% of 49 strains tested. Strain 58, one of the indicator strains, was affected by the bactericidal activity of these bacteriocins but not by CF activity, and failed to transform. No relationship between the bacteriocin-producing strains and indicator strains was observed. Both Challis and 36658 bacteriocin activities decreased markedly either when the bacteriocins were heated at 50 C for 30 min or with the addition of a protein synthesis inhibitor, but showed different sensitivities to trypsin, papain and lipase. The bacteriocins were of at least protein nature and their molecular weight was roughly estimated as 100,000 daltons by membrane filtration experiments. The 36658 bacteriocin is a new type of streptocin previously not reported. The possible absence of bacteriophage or phage-like particles in the preparations is discussed.

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confidence: 70%

Group H Streptococcal Bacteriocins Having No Relation to Bacterial Transformation

Ito

1982

Microbiology and Immunology

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“…However, two other candidates for regulatory circuit genes do exist. In Streptococcus sanguis, the Wicky strain depends for competence on exogenous CF, which can be supplied from competent cultures of the spontaneously competent Challis strain; thus, Wicky appears to be a naturally occurring com strain (36,46). In S. pneumoniae, the trt mutation (33), which causes cells to be constitutively competent and to retain that competence even during growth in trypsin, may represent an alteration in the CF-response circuitry which bypasses the CF activation step entirely.…”

Section: Resultsmentioning

confidence: 99%

Genetic transformation in Streptococcus pneumoniae: nucleotide sequence analysis shows comA, a gene required for competence induction, to be a member of the bacterial ATP-dependent transport protein family

1991

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“…Further, subtle changes in the cell surface which develop under some conditions during growth are apparently responsible for competence in transformation. In competence development in Pneumococcus and Streptococcus, chemically and serologically identifiable materials appear quite abruptly in growing cultures, and again disappear, at least partly as a result of enzymic action (Tomasz & Hotchkiss, 1964;Tomasz & Beiser, 1965;Pakula & Walczac, 1963). With Bacillus subtilis, wall-surface modifications also have been reported to accompany changes in competence (Charpak & Dedonder, 1965;Jensen & Haas, 1963;Young, 1965;Young, 1966); again these variations occur well within the compass of a few divisions or, indeed, in the absence of division (Archer & Landman, 1967).…”

Section: Discussionmentioning

confidence: 99%

The Formation of Protoplasts and Quasi-spheroplasts in Normal and Chloramphenicol-pretreated Bacillus subtilis

Miller¹,

Zsigray²,

Landman³

1967

Journal of General Microbiology

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The lytic action of lysozyme upon Bacillus subtilis walls was studied by following the disappearance of bacillary-colony-forming units and the appearance of L-colony-forming-units. The rapidity of cell wall removal by lysozyme fluctuated markedly during growth in a chemically defined medium, presumably because subtle changes in the cell wall were constantly occurring. When lysozyme-sensitive bacilli were grown with chloramphenicol 10 pg./ml. for 3 hr they showed a notable increase in lysozyme resistance; at the same time, their walls almost doubled in thickness. As lysozyme attack proceeded in a given culture, the bacilli passed first through a rod-shaped osmotically sensitive stage, and then a spherical stage characterized by incomplete removal of cell wall before finally reaching the naked protoplast stage. The spherical forms with adherent wall residues formed L colonies on a medium containing the reversion inhibitor D-methionine and bacillary colonies on the same medium without D-methionine. Under the latter conditions, the cell wall residue served as a starting point for rebuilding of complete wall, much as residual wall permits reversion of Gram-negative spheroplasts to the bacillary state. In the presence of Dmethionine, the feedback sequence required for wall formation was severed, resulting in heritable propagation of the protoplast state.

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On the Nature of Competence of Transformable Streptococci

Cited by 200 publications

References 4 publications

Group H Streptococcal Bacteriocins Having No Relation to Bacterial Transformation

Group H Streptococcal Bacteriocins Having No Relation to Bacterial Transformation

Genetic transformation in Streptococcus pneumoniae: nucleotide sequence analysis shows comA, a gene required for competence induction, to be a member of the bacterial ATP-dependent transport protein family

The Formation of Protoplasts and Quasi-spheroplasts in Normal and Chloramphenicol-pretreated Bacillus subtilis

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