RESUMO
Penicillin tolerance was elicited in 18 of 46 strains of viridans streptococci isolated from the mouths of 19 of 20 healthy subjects and in 31 of 54 consecutive blood-culture isolates of streptococci. Enterococci and Streptococcus sanguis were the organisms most frequently tolerant but the property was also common among isolates of S. mutans, S. mitior and Lancefield Group G streptococci. Pneumococci and S. salivarius were rarely tolerant. When incubated with penicillin at 5 x MIC in batch or continuous cultures, both tolerant and sensitive strains of oral streptococci declined in number less rapidly than S. pyogenes. However, combinations of penicillin and gentamicin killed tolerant and sensitive oral streptococci.
Assuntos
Boca/microbiologia , Resistência às Penicilinas , Streptococcus/efeitos dos fármacos , Tolerância a Medicamentos , Humanos , Streptococcus mutans/efeitos dos fármacos , Streptococcus pneumoniae/efeitos dos fármacos , Streptococcus pyogenes/efeitos dos fármacos , Streptococcus sanguis/efeitos dos fármacosRESUMO
An assay based on reverse transcription and nested PCR amplification of hypervariable regions within the 16S rRNA sequence was used to specifically detect Renibacterium salmoninarum, the slowly growing causative agent of bacterial kidney disease in salmonid fish. This assay detected 1 to 10 bacteria per sample and took 1 to 2 days to perform. The assay was used to detect R. salmoninarum in ovarian fluid obtained from naturally infected fish. The assay was unreliable when it was used to examine kidney tissue.