Molecular analysis of constitutive mutations in ermB and ermA selected in vitro from inducibly MLSB-resistant enterococci.
Frequencies of spontaneous mutation from inducible resistance to constitutive resistance were determined for the four clinical isolates of erythromycin-resistant enterococci, including one isolate with ermB gene and three clinical isolates with ermA gene. The rate of ermB mutation was higher than that of ermA mutation by more than 10 fold. Sequence analysis of the regulatory regions of erm genes revealed that mutation type of ermB was just point mutation, by contraries the mutation type of ermA was either deletion or tandem duplication. These results showed distinct characteristics in mutation patterns of ermB and ermA.
Min
Yu-Hong
YH
College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 151-742, Korea.
Kwon
Ae-Ran
AR
Yoon
Jong-Min
JM
Yoon
Eun-Jeong
EJ
Shim
Mi-Ja
MJ
Choi
Eung-Chil
EC
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics*; D004252:DNA Mutational Analysis; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D013293:Enterococcus faecalis / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D016984:Enterococcus faecium / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D004917:Erythromycin / Q000494:pharmacology; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D005838:Genotype; D015570:Josamycin / Q000494:pharmacology; D018942:Macrolides / Q000494:pharmacology*; D008780:Methyltransferases / Q000235:genetics*; D009154:Mutation; D010641:Phenotype; D017354:Point Mutation; D017384:Sequence Deletion
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D018942:Macrolides; D004917:Erythromycin; D008780:Methyltransferases; C431709:ErmA protein, Bacteria; C035181:rRNA (adenosine-O-2'-)methyltransferase; D015570:Josamycin