The Genetic Relationship and Phenotypic Expression of Mutations Endowing Pneumococcus with Resistance to Erythromycin

Ravin, Arnold W.; Iyer, V. N.

doi:10.1099/00221287-26-2-277

Cited by 28 publications

(29 citation statements)

References 20 publications

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“…Genetic analyses have revealed that in Escherichia coli the stepwise resistance pattern to ampicillin (1, 2, 7), chloramphenicol and tetracycline (19), and cycloserine (5) is polygenic in nature. Similar conclusions have been reached with regard to the resistance ofStreptococcus pneumoniae to ampicillin (4,23), erythromycin (17), and sulfonamide (10). Gonococcal resistance to penicillin, tetracycline (11), and other antibiotics (20) is acquired in vitro by the selection of successive stepwise mutations.…”

supporting

confidence: 63%

Genetic analysis of drug resistance in Neisseria gonorrhoeae: production of increased resistance by the combination of two antibiotic resistance loci

Maier¹,

Zubrzycki²,

Coyle³

et al. 1975

J Bacteriol

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The studies reported here demonstrate that increased resistance of Neisseria gonorrhoeae to penicillin, tetracycline, and chloramphenicol results from the combined effect of two resistance loci. As shown by experiments with deoxyribonucleic acid from transformants carrying only a single resistance locus, transformants with an increased level of resistance to penicillin result from the combination of a penicillin-specific locus, pen, and a multiple resistance locus, mtr. Similarly, transformants with an increased level of resistance to tetracycline result from the combination of mtr and a tetracycline-specific locus, tet. Transformants with an increased level of resistance to chloramphenicol result from the combination of mtr and a chloramphenicol-specific locus, cml. Deoxyribonucleic acid dilution experiments established that only a single dose of each of the two required resistance loci is necessary to give higher-level resistance. Higher-level-resistant transformants were not obtained when a double dose of one resistance locus or a combination of loci pairs other than mtr and pen, mtr and tet, or mtr and cml was introduced into a recipient. Combinations of the mtr and tet genes resulted in increased resistance to semisynthetic tetracyclines. The presence of the mtr and pen genes resulted in increased resistance to penicillinase-stable penicillins.

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supporting

confidence: 63%

Genetic analysis of drug resistance in Neisseria gonorrhoeae: production of increased resistance by the combination of two antibiotic resistance loci

Maier¹,

Zubrzycki²,

Coyle³

et al. 1975

J Bacteriol

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“…Diplococcus pneumoniae strain r,SQ, derived from strain rz of Ravin and Iyer (1961) by transformation, carrying the ery-r2, str-41, and opt-r2 genes giving resistance to erythromycin, streptomycin and optochin respectively.…”

Section: Materials a N D Methodsmentioning

confidence: 99%

Characterization by Transformation of an Ampicillin-resistant Mutant of Pneumococcus

Butler

Smiley

1970

Journal of General Microbiology

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SUMMARYMutagenesis of a transformable strain of pneumococcus by N-methy1-N'-nitro-N-nitrosoguanidine produced several mutants resistant to ampicillin. One of these was resistant to 0.1 pg. ampicillin/ml., but a purified solution of its DNA transformed the sensitive parent to three different levels of resistance at frequencies compatible with single, double and triple transformants. The higher levels of resistance were dependent on the presence of the genes conferring the lower resistances. Furthermore, transformants to the higher levels of resistance can be obtained at single or double frequency by using as recipient the strain already possessing the genes conferring the lower resistances. The expression times of the ampicillin genes are short (approximately 25 min.), but the actual times were difficult to determine since there was a delay of some 15 to 20 min. before the ampicillin exerted an effect on the sensitive strain under these conditions. I N T R O D U C T I O NIn the course of experiments designed to map the relative positions of genes on the pneumococcus chromosome, it became necessary to make and characterize new markers to add to those already available. For this purpose, mutagenesis by N-methy1-N'-nitro-N-nitrosoguanidine (NNG) was performed and mutants having auxotrophic properties or antibiotic resistances were looked for. Amongst these were mutants resistant to ampicillin, and the characteristics relating to the transforming properties of one of these are described below. MATERIALS A N D METHODSOrganisms. Diplococcus pneumoniae strain CI 3, derived from strain ~3 6~ of Avery, MacLeod & McCarty (I 944) by Ephrussi-Taylor (1 95 I), sensitive to streptomycin and ampicillin. Stock cultures were kept as previously described (Butler, I 965).Diplococcus pneumoniae strain r,SQ, derived from strain rz of Ravin and Iyer (1961) by transformation, carrying the ery-r2, str-41, and opt-r2 genes giving resistance to erythromycin, streptomycin and optochin respectively.Media. The peptone media 'P' and 'NS' were prepared as previously described (Sicard, 1965; Butler, 1969, and the synthetic medium of Sicard (1965) was used in the mutagenic reaction with the following additions : glutamic acid 80 mg./l., aspartic acid 95 mg./l., tryptophan IOO mg./ml., serine 125 mg./l., proline 200 mg./l., phenylalanine 250 mg./l., adenine 18 mg./I. These compounds were added to allow the survival of auxotrophs.

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“…The synergistic action of certain linked ery mutations has also been demonstrated in pneumoccocus by Ravin & Iyer (1961). Such stepwise development of resistance is not restricted to the macrolide antibiotics but may also occur with a number of other…”

Section: Discussionmentioning

confidence: 93%

Resistance Pattern and Genetics of Erythromycin-resistant Mutants of Streptococcus pyogenes

Malke¹

1970

Journal of General Microbiology

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S U M M A R YSingle-step erythromycin-resistant strains of Streptococcus pyogenes 561 88 fell into two classes: whereas class A mutants were sensitive to lincomycin and carried mutations transducible by phage A 25, class B mutations conferred lincomycin cross-resistance and failed to be transducible under the conditions employed. Recombination and cotransduction experiments allowed the assigning of at least 10 of 13 class A mutations to the same linkage group. From interclass crosses recombinants emerged at frequencies comparable with those at which the donor markers were integrated into wild type. The resistance to three macrolides and lincomycin of interclass recombinants, carrying mutations which were not cotransducible, was related to the resistance levels determined by the individual mutations. The phenotypic properties of the ery mutants together with their genetic relationship lead to the conclusion that there are at least two loci governing resistance to erythromycin in strain 56188 of S. pyogenes.

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The Genetic Relationship and Phenotypic Expression of Mutations Endowing Pneumococcus with Resistance to Erythromycin

Cited by 28 publications

References 20 publications

Genetic analysis of drug resistance in Neisseria gonorrhoeae: production of increased resistance by the combination of two antibiotic resistance loci

Genetic analysis of drug resistance in Neisseria gonorrhoeae: production of increased resistance by the combination of two antibiotic resistance loci

Characterization by Transformation of an Ampicillin-resistant Mutant of Pneumococcus

Resistance Pattern and Genetics of Erythromycin-resistant Mutants of Streptococcus pyogenes

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