Radiation-sensitive and radiation-resistant mutants of Haemophilus influenzae

Barnhart, Benjamin J.; Cox, Summers H.

doi:10.1128/jb.96.1.280-282.1968

Cited by 48 publications

(9 citation statements)

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“…Among the survivors in bacterial cultures subjected to high irradiation doses, cells more radioresistant than the parent strain have oftentimes been isolated. This has been reported for cultures of Escherichia coli (10,16), a strain of Alcaligenes (13), and Haemophilus influenza (2).…”

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confidence: 56%

Development of Radiation Resistance in Salmonella Cultures1

Licciardello

Nickerson

Goldblith

et al. 1969

Applied Microbiology

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Cultures of Salmonella subjected to repeated cycles of gamma-irradiation and subculture developed radiation resistance sooner at a low cycling dose (-1 % survival) compared to a high cycling dose (-0.001 % survival). Radioresistant cells in a population of radiosensitive cells of Salmonella newport or S. typhimurium could be selected by the double-irradiation plate method. The frequency of radioresistant cells in a population of S. newport was found to be about 1 per 8.9 million. Radioresistant cells obtained by cyclic irradiation and subculture were larger (plumper) than the parent strain and showed a marked pleomorphism.

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confidence: 56%

Development of Radiation Resistance in Salmonella Cultures1

Licciardello

Nickerson

Goldblith

et al. 1969

Applied Microbiology

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“…If strain BC200 would carry a defective phage, no prophage induction would be detected (3). Strain BC200 is less sensitive to UV irradiation than an Rd strain of H. influenzae (1). However, since the cell survival after UV irradiation of strain HM5(BC200) (constructed by transfer of the mutation conferring MC sensitivity upon strain HM5 into the BC200 strain) was, relative to that of the BC200 strain, reduced to the same extent ( Fig.…”

Section: Resultsmentioning

confidence: 99%

Characterization of a conditionally transformation-deficient mutant of Haemophilus influenzae that carries a mutation in the rec-1 gene region

Kooistra¹,

Boxel²,

Venema³

1983

J Bacteriol

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A mutant of Haemophilus influenzae, designated HM5, carrying a mutation in the rec-1 gene region, is described. This mutant transformed approximately 100fold less well than does the wild type, but approximately 100-fold better than recl mutants. The mutant was less sensitive to UV irradiation and less "reckless" than recl mutants. In contrast to recl lysogens, HPlcl lysogens of the mutant were inducible, and during transformation, recombinant-type activity was formed to the same extent as in the wild type. Although the integration of donor DNA was complete, the integrated DNA was not replicated at 36°C. Both the inhibition of replication of the donor-recipient DNA complex and the transformation deficiency could be suppressed when, after DNA entry, the cells were incubated under suboptimal conditions. The loss of colony formation after UV irradiation was suppressible by the same conditions. 852 on July 15, 2020 by guest

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“…In all matings involving a Rec+ recipient, 125 ,ug of DNase per ml was added to the mating mixture. The plates were incubated for 2 or 3 h before the cells were suspended and plated with antibiotics selective for each of the donors, the recipient and the transconjugants (5 ,ug of ampicillin per ml, 4 novobiocin per ml, 250 jig of streptomycin per ml, 7 ,ug of kanamycin per ml). The frequency of conjugative transfer was expressed as the number of transconjugants per recipient.…”

Section: Methodsmentioning

confidence: 99%

Differential behavior of plasmids containing chromosomal DNA insertions of various sizes during transformation and conjugation in Haemophilus influenzae

Balganesh¹,

Setlow²

1985

J Bacteriol

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Plasmids with chromosomal insertions were constructed by removal of a 1.1-kilobase-pair piece from the 9.8-kilobase-pair vector plasmid pDM2 by EcoRI digestion and inserting in its place various lengths of chromosomal DNA (1.7, 3.4, and 9.0 kilobase pairs) coding for resistance to novobiocin. A fourth plasmid was constructed by insertion of the largest piece of chromosomal DNA into the SmaI site of pDM2. The plasmids without inserts were taken up poorly by competent cells and thus were considered not to contain specific DNA uptake sites. The presence of even the smallest insert of chromosomal DNA caused a large increase in transformation of Rec+ and Rec- strains. The frequency of plasmid establishment in Rec+ cells by transformation increased exponentially with increasing insert size, but in Rec- cells there was less transformation by the larger plasmids. Conjugal transfer of these plasmids was carried out with the 35-kilobase-pair mobilizing plasmid pHD147. The frequency of establishment of plasmids by this method not only was not markedly affected by the presence of the insertions, but also decreased somewhat with increase in insert size and was independent of rec-1 and rec-2 genes. Recombination between plasmid and chromosome was readily detected after transformation, but could not be detected after transconjugation even when the recipient cells were Rec+ and made competent. These data suggested that there is a special processing of plasmid DNA that enters the competent cells in transformation that makes possible recombination of homologous regions of the plasmid with the chromosome and pairing with the chromosome that aids plasmid establishment.

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Radiation-sensitive and radiation-resistant mutants of Haemophilus influenzae

Cited by 48 publications

References 0 publications

Development of Radiation Resistance in Salmonella Cultures1

Development of Radiation Resistance in Salmonella Cultures1

Characterization of a conditionally transformation-deficient mutant of Haemophilus influenzae that carries a mutation in the rec-1 gene region

Differential behavior of plasmids containing chromosomal DNA insertions of various sizes during transformation and conjugation in Haemophilus influenzae

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