Polymorphic mutation frequencies in Escherichia coli: emergence of weak mutators in clinical isolates.
Polymorphisms in the rifampin resistance mutation frequency (f) were studied in 696 Escherichia coli strains from Spain, Sweden, and Denmark. Of the 696 strains, 23% were weakly hypermutable (4 x 10(-8) < or = f < 4 x 10(-7)), and 0.7% were strongly hypermutable (f > or = 4 x 10(-7)). Weak mutators were apparently more frequent in southern Europe and in blood isolates (38%) than in urinary tract isolates (25%) and feces of healthy volunteers (11%).
Servicio de Microbiología, Hospital Ramón y Cajal, Madrid, Spain. fbaquero.hrc@salud.madrid.org
María-Rosario
MR
Baquero
Annika I
AI
Nilsson
María del Carmen
Mdel C
Turrientes
Dorthe
D
Sandvang
Juan Carlos
JC
Galán
Jose Luís
JL
Martínez
Niels
N
Frimodt-Møller
Fernando
F
Baquero
Dan I
DI
Andersson
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001769:Blood / Q000382:microbiology; D003718:Denmark; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology; D005243:Feces / Q000382:microbiology; D005798:Genes, Bacterial; D006801:Humans; D009154:Mutation; D011110:Polymorphism, Genetic; D012293:Rifampin / Q000494:pharmacology*; D013030:Spain; D013548:Sweden; D014552:Urinary Tract Infections / Q000382:microbiology
D000900:Anti-Bacterial Agents; D012293:Rifampin