Environmental mutagens may be implicated in the emergence of drug-resistant microorganisms.
The emergence of drug-resistant microorganisms is an important medical and social problem. Drug-resistant microorganisms are thought to grow selectively in the presence of antibiotics. Most clinically isolated drug-resistant microorganisms have mutations in the target genes for the drugs. While any of the many mutagens in the environment may cause such genetic mutations, no reports have yet described whether these mutagens can confer drug resistance to clinically important microorganisms. We investigated how environmental mutagens might be implicated in acquired resistance to antibiotics in clinically important microorganisms, which causes human diseases. We selected mutagens found in the environment, in cigarette smoke, or in drugs, and then exposed Pseudomonas aeruginosa to them. After exposure, the incidence of rifampicin- and ciprofloxacin-resistant P. aeruginosa strains markedly increased, and we found mutations in genes for the antibiotic-target molecule. These mutations were similar to those found in drug-resistant microorganisms isolated from clinical samples. Our findings show that environmental mutagens, and an anticancer drug, are capable of inducing drug-resistant P. aeruginosa similar to strains found in clinical settings.
Department of Environmental Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan.
Emiko
E
Miyahara
Makiko
M
Nishie
Shota
S
Takumi
Hiroaki
H
Miyanohara
Junichiro
J
Nishi
Kiyotaka
K
Yoshiie
Hiroshi
H
Oda
Minoru
M
Takeuchi
Masaharu
M
Komatsu
Kohji
K
Aoyama
Masahisa
M
Horiuchi
Toru
T
Takeuchi
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D001580:Benzopyrenes / Q000633:toxicity; D002330:Carmustine / Q000633:toxicity; D002939:Ciprofloxacin / Q000494:pharmacology; D027081:DNA Gyrase / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000235:genetics; D005020:Ethyl Methanesulfonate / Q000633:toxicity; D008782:Methylurea Compounds / Q000633:toxicity; D009602:Nitrosamines / Q000633:toxicity; D016133:Polymerase Chain Reaction; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000235:genetics*; D012293:Rifampin / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D001580:Benzopyrenes; D008782:Methylurea Compounds; D009602:Nitrosamines; D002939:Ciprofloxacin; D005020:Ethyl Methanesulfonate; D027081:DNA Gyrase; D002330:Carmustine; D012293:Rifampin; C008655:N'-nitrosonornicotine