Biomaterial Database

In vitro studies of 5-fluorocytosine resistance in Candida albicans and Torulopsis glabrata. 1972

S Normark, and J Schönebeck

Spontaneous mutants of Candida albicans resistant to 5-fluorocytosine (5-FC) were isolated from a strain susceptible to 5-FC. These mutants were compared with 5-FC-resistant strains of C. albicans and Torulopsis glabrata isolated from patients treated with the drug and from untreated patients. Resistance to 5-FC was in all cases followed by a decreased susceptibility to 5-fluorouracil. Most strains were also more resistant to 5-fluorouridine and had a lowered incorporation of uridine. In one spontaneous mutant totally resistant to all three 5-fluoropyrimidines, the uridine monophosphate pyrophosphorylase activity was greatly decreased. The 5-FC-resistant strains were of two main phenotypic classes. Class one was unaffected by 5-FC at the highest concentration tested. The growth rate of strains belonging to the other class was markedly decreased by low concentrations of 5-FC, but these strains were still able to form colonies after 7 days of incubation on plates containing very high concentrations of the drug (2,000 mug/ml). The frequency of spontaneous mutation of a susceptible strain to 5-FC resistance was fairly high. The number of mutants growing on media containing 5-FC was unchanged by concentrations ranging from 25 to 500 mug/ml.

UI	MeSH Term	Description	Entries
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D002175	Candida	A genus of yeast-like mitosporic Saccharomycetales fungi characterized by producing yeast cells, mycelia, pseudomycelia, and blastophores. It is commonly part of the normal flora of the skin, mouth, intestinal tract, and vagina, but can cause a variety of infections, including CANDIDIASIS; ONYCHOMYCOSIS; VULVOVAGINAL CANDIDIASIS; and CANDIDIASIS, ORAL (THRUSH).	Candida guilliermondii var. nitratophila,Candida utilis,Cyberlindnera jadinii,Hansenula jadinii,Lindnera jadinii,Monilia,Pichia jadinii,Saccharomyces jadinii,Torula utilis,Torulopsis utilis,Monilias
D002176	Candida albicans	A unicellular budding fungus which is the principal pathogenic species causing CANDIDIASIS (moniliasis).	Candida albicans var. stellatoidea,Candida stellatoidea,Dematium albicans,Monilia albicans,Myceloblastanon albicans,Mycotorula albicans,Parasaccharomyces albicans,Procandida albicans,Procandida stellatoidea,Saccharomyces albicans,Syringospora albicans
D003596	Cytosine	A pyrimidine base that is a fundamental unit of nucleic acids.
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
D005437	Flucytosine	A fluorinated cytosine analog that is used as an antifungal agent.	5-Fluorocytosine,Alcobon,Ancobon,Ancotil
D000935	Antifungal Agents	Substances that destroy fungi by suppressing their ability to grow or reproduce. They differ from FUNGICIDES, INDUSTRIAL because they defend against fungi present in human or animal tissues.	Anti-Fungal Agents,Antifungal Agent,Fungicides, Therapeutic,Antibiotics, Antifungal,Therapeutic Fungicides,Agent, Antifungal,Anti Fungal Agents,Antifungal Antibiotics