SUMMARY: Single-step erythromycin-resistant strains of Streptococcus pyogenes 56188 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 pheno-typic 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.
BarberM.,
WaterworthP. M.1964; Antibacterial activity of lincomycin and pristinamycin: A comparison with erythromycin.. British Medical Journal ii: 603–606
GunsalusI. C.,
GunsalusC. F.,
ChakrabartyA. M.,
SikesS.,
CrawfordI. P.1968; Fine structure mapping of the tryptophan genes in Pseudomonas putida.. Genetics 60:419–435
JonesW. F.,
NicholsR. L.,
FinlandM.1956; Development of resistance and cross-resistance in vitro to erythromycin, carbomycin, spiramycin, oleandomycin and streptogramin.. Proceedings of the Society for Experimental Biology and Medicine 93:388–393
KjemsE.1958; Studies on streptococcal bacteriophages. II. Adsorption, lysogenization, and one-step growth experiments.. Acta pathologica et microbiologica scandinavica 42:56–66
MalkeH.1967; Host-cell reactivation of ultraviolet-damaged phage in Streptococcus pyogenes.. Biochemical and Biophysical Research Communications 29:400–405
MalkeH.1969; Transduction of Streptococcus pyogenes K56 by temperature-sensitive mutants of the transducing phage A25.. Zeitschrift für Naturforschung 24b:1556–1561
McGeheeR. F.,
BarrettF. F.,
FinlandM.1969; Resistance of Staphylococcus aureus to lincomycin, clinimycin, and erythromycin.. Antimicrobial Agents and Chemotherapy 1968:392–397
PatteeP. A.,
BaldwinJ. N.1962; Transduction of resistance to some macrolide antibiotics in Staphylococcus aureus.. Journal of Bacteriology 84:1049–1055
RavinA. W.,
IyerV. N.1961; The genetic relationship and phenotypic expression of mutations endowing pneumoccocus with resistance to erythromycin.. Journal of General Microbiology 26:277–301
SirotnakF. M.,
HachtelS. L.1969; Increased dihydrofolate reductase synthesis in Diplococcus pneumoniae following translatable alteration of the structural gene. I. Genotype derivation and recombinational analyses.. Genetics 61:293–312