Analysis of antibiotic susceptibility and extrachromosomal DNA content of XXXX and @entity39989 .

@entity1214 @entity7913 @entity26 @entity2929 @entity39989 @entity3639 @entity41193 @entity803 @entity8294
Seventeen @entity8294 and @entity39989 strains have been screened for naturally occurring antibiotic resistance, as determined by zones of inhibition from antibiotic disks. These strains were also examined for extrachromosomal DNA content. All strains screened are resistant to low levels (10-200 micrograms/mL) of @entity3639 . In contrast to the previously reported data, we have found that @entity39989 C-94 is now susceptible to both @entity7913 and @entity803 . However, @entity39989 @entity41193 is not susceptible to @entity7913 (minimum inhibitory concentration (MIC) = 40 micrograms/mL). Furthermore, @entity8294 8 is resistant to @entity803 (MIC = 40 micrograms/mL), and @entity2929 (MIC = 100 micrograms/mL). Six freshly isolated strains showed resistance to @entity803 (35-70 micrograms/mL), and all @entity803 -resistant strains also showed resistance to @entity1214 . None of these @entity8294 determinants share homology with the streptococcal tetL, tetM, or tetN determinants. All 17 strains were screened for extrachromosomal DNA content. Nine different techniques for the detection and isolation of extrachromosomal DNA were tested. However, owing to difficulties in demonstrating or isolating plasmid DNA, it has not been possible to determine if these antibiotic resistance genes are plasmid borne. Evidence is presented to suggest that the presence of @entity26 may affect the quality of the DNA obtained from @entity8294 .
