Spectrum and resistance determinants of oral streptococci clinical isolates

Fusidic Acid Resistance Determinants in Staphylococcus aureus Clinical Isolates 1

Fusidic acid resistance determinants in Staphylococcus aureus clinical isolates.

A total of 71 fusidic acid-resistant Staphylococcus aureus (45 methicillin-resistant and 26 methicillin-susceptible) isolates were examined for the presence of resistance determinants. Among 45 fusidic acid-resistant methicillin-resistant S. aureus (MRSA), isolates, 38 (84%) had fusA mutations conferring high-level resistance to fusidic acid (the MIC was ≥128 μg/ml for 22/38), none had fusB, an...

Prevalence and mechanisms of macrolide resistance in clinical isolates of group A streptococci from Ontario, Canada.

A total of 3,205 group A streptoccal isolates were collected in 1997 through a private laboratory which serves community physicians in southern Ontario and which represents a population base of 6 million people. Nonsusceptibility to erythromycin was detected for 67 (2.1%) isolates both by disk diffusion and by broth microdilution. Of these, 47 (70%) were susceptible to clindamycin and were foun...

Comparison of Distribution of Virulence Determinants in Clinical and Environmental Isolates of Vibrio cholera

Background: The virulence of a pathogenic Vibrio cholerae is dependent on a discrete set of genetic determinants. In this study, we determined the distribution of virulence determinants among the clinical and environmental isolates of V. cholerae. Methods: The antibiotic resistance profiles of the isolates were determined using standard disk diffusion assay. PCR assay was performed to analyze t...

Resistance to penicillin-streptomycin synergy among clinical isolates of viridans streptococci.

Viridans streptococci are thought to be highly susceptible to penicillin and streptomycin. We recently encountered a unique group of 15 isolates from South Africa epidemiologically related to the isolation of penicillin-resistant pneumococci. These organisms were highly resistant to penicillin (PCN) (minimal inhibitory concentration, 1 to 32 micrograms/ml) and streptomycin (SM) (minimal inhibit...