Biomaterial Database

Characteristics of rifampin-resistant variants obtained from clinical isolates of Staphylococcus aureus. 1981

D R Moorman, and G L Mandell

Twenty clinical isolates of Staphylococcus aureus were examined to determine the frequency of rifampin-resistant variants. All isolates were highly susceptible to rifampin, with mean minimum inhibitory concentrations of 0.11 +/- 0.1 microgram/ml and mean minimum bactericidal concentrations of 0.22 +/- 0.2 microgram/ml. The frequency of isolation of resistant variants was similar to all rifampin concentrations tested. Rifampin-resistant variants maintained their resistance upon daily subculture in rifampin-free broth. Rifampin-susceptible S. aureus exhibited a growth and survival advantage over the rifampin-resistant mutants both in pure cultures and in mixtures with rifampin-resistant antecedents. A comparison of the virulence for mice of five susceptible isolates and their 100 microgram/ml-rifampin-resistant variants showed that two of the resistant variants were less virulent than the susceptible strains via intraperitoneal challenge, whereas three of the resistant variants were less virulent by intravenous challenge (P less than 0.05).

UI	MeSH Term	Description	Entries
D004352	Drug Resistance, Microbial	The ability of microorganisms, especially bacteria, to resist or to become tolerant to chemotherapeutic agents, antimicrobial agents, or antibiotics. This resistance may be acquired through gene mutation or foreign DNA in transmissible plasmids (R FACTORS).	Antibiotic Resistance,Antibiotic Resistance, Microbial,Antimicrobial Resistance, Drug,Antimicrobial Drug Resistance,Antimicrobial Drug Resistances,Antimicrobial Resistances, Drug,Drug Antimicrobial Resistance,Drug Antimicrobial Resistances,Drug Resistances, Microbial,Resistance, Antibiotic,Resistance, Drug Antimicrobial,Resistances, Drug Antimicrobial
D005260	Female		Females
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012293	Rifampin	A semisynthetic antibiotic produced from Streptomyces mediterranei. It has a broad antibacterial spectrum, including activity against several forms of Mycobacterium. In susceptible organisms it inhibits DNA-dependent RNA polymerase activity by forming a stable complex with the enzyme. It thus suppresses the initiation of RNA synthesis. Rifampin is bactericidal, and acts on both intracellular and extracellular organisms. (From Gilman et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 9th ed, p1160)	Rifampicin,Benemycin,Rifadin,Rimactan,Rimactane,Tubocin
D013203	Staphylococcal Infections	Infections with bacteria of the genus STAPHYLOCOCCUS.	Infections, Staphylococcal,Staphylococcus aureus Infection,Staphylococcal Infection,Staphylococcus aureus Infections
D013211	Staphylococcus aureus	Potentially pathogenic bacteria found in nasal membranes, skin, hair follicles, and perineum of warm-blooded animals. They may cause a wide range of infections and intoxications.
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor
D051379	Mice	The common name for the genus Mus.	Mice, House,Mus,Mus musculus,Mice, Laboratory,Mouse,Mouse, House,Mouse, Laboratory,Mouse, Swiss,Mus domesticus,Mus musculus domesticus,Swiss Mice,House Mice,House Mouse,Laboratory Mice,Laboratory Mouse,Mice, Swiss,Swiss Mouse,domesticus, Mus musculus