Genetic analysis of antibiotic resistance in Streptococcus pyogenes

Abstract

The genetics of antibiotic resistance in mutant strains of Streptococcus pyogenes was studied. Utilizing a type 6 strain (9440) primarily resistant to streptomycin (Strr), classes of mutant strains were isolated that were resistant to one of the following antibiotics: rifampin (RiP), erythromycin (Eryr), thiostrepton (Tstr), spiramycin (Spr), fusidic acid (Fusr), gramicidin (Grcr), ethidium bromide (Ebrr), kanamycin (Kanr), neomycin (Neor), oleandomycin (Oler), gentamicin (Genr), and novobiocin (Novr). Transduction experiments separated antibiotic resistance markers into two distinct groups: transducible markers, including Fusr, Bacr, Ksg, SpCr, EYr, Sprr, Rift, Stlr, and Tstr (Bacr, Ksgr, Spcr, and Stlr refer to resistance to bacitracin, kasugamycin, spectinomycin, and streptolydigan, respectively), and nontransducible markers, including Grcr, Ebrr, Kanr, Neor, Oler, Genr, and Novr. By means of two-and three-point crosses, transducible markers (excluding tst) were located in three separate linkage groups. spr was found to be linked with ery and spc in the order spc-ery-spr, whereas in a separate linkage on August 1, 2020 by guest

Antibiotics of the virginiamycin family, inhibitors which contain synergistic components.

“…The overall conclusion is that, although a cross-resistant pattern to macrolides and virginiamycin-like antibiotics is frequent, a dissociation of the two types of resistance can be obtained (cf. 42-44, and 91,157,280).…”

Electrotransformation of Streptococcus pyogenes with plasmid and linear DNA

“…The methods of gene transfer most widely used in the group A streptococci have been transduction [1,2] and conjugation [3,4]. Although transduction has been useful in establishing several linkage groups of antibiotic resistance markers [5,6], and conjugation has been used in the transfer of selected genes [7], neither of these methods of gene transfer has been useful for work involving cloned DNA. Transformation is the method of choice for introduction of either native or genetically engi-neered DNA into microorganisms, although until recently this method of gene transfer had not been successfully demonstrated in the group A streptococci.…”