Two hundred selected Swedish clinical strains of Streptococcus pyogenes, identified as erythromycin-resistant and isolated between 1980 and 1988, and 37 consecutive, resistant strains from 1989-90 were examined for resistance phenotype by disc diffusion. Strains constitutively resistant to macrolides, lincosamides and streptogramin B were absent in 1980-85 but accounted for 10% in 1986-88. The ...

Erythromycin is the drug of choice for treatment of Mycoplasma pneumoniae infections due to its susceptibility to low levels of this antibiotic. After exposure of susceptible strains to erythromycin in vitro and in vivo, mutants resistant to erythromycin and other macrolides were isolated. Their phenotypes have been characterized, but the genetic basis for resistance has never been determined. ...

We evaluated the activities of quinupristin-dalfopristin (Q-D), alone or in combination with rifampin, against three strains of Staphylococcus aureus susceptible to rifampin (MIC, 0.06 microg/ml) and to Q-D (MICs, 0.5 to 1 microg/ml) but displaying various phenotypes of resistance to macrolide-lincosamide-streptogramin antibiotics: S. aureus HM1054 was susceptible to quinupristin and dalfoprist...

INTRODUCTION MRSA population dynamics is undergoing significant changes, and for this reason it is important to know which clones are circulating in our nosocomial environment. MATERIALS AND METHODS A total of 118 MRSA isolates were collected from clinical samples from patients with previous hospital or healthcare contact (named as hospital-onset MRSA (HO-MRSA)) during a one year period. Susc...

Increasing frequency of methicillin resistant Staphylococcus aureus (MRSA) infections and changing patterns in antimicrobial resistance have led to renewed interest in the use of macrolide-lincosamide-streptogramin (MLS) antibiotics to treat such infections. Inducible macrolides, lincosamides, type B streptogramins (MLS(Bi)) resistance has to be identified to avoid clinical failure of clindamyc...

The in vitro susceptibilities of 266 isolates of Streptococcus agalactiae determined by the agar dilution method showed that 6% of isolates were nonsusceptible to penicillin and 46% was resistant to erythromycin. Of the erythromycin-resistant isolates, 86.3% had the macrolide-lincosamide-streptogramin (MLS) resistance phenotype (constitutive MLS, 85.5%; inducible MLS, 0.8%) and 13.7% had the M ...