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%).
Baquero
María-Rosario
MR
Servicio de Microbiología, Hospital Ramón y Cajal, Madrid, Spain. fbaquero.hrc@salud.madrid.org
Nilsson
Annika I
AI
Turrientes
María del Carmen
Mdel C
Sandvang
Dorthe
D
Galán
Juan Carlos
JC
Martínez
Jose Luís
JL
Frimodt-Møller
Niels
N
Baquero
Fernando
F
Andersson
Dan I
DI
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