Lethal mutagenesis of bacteria.
نویسندگان
چکیده
Lethal mutagenesis, the killing of a microbial pathogen with a chemical mutagen, is a potential broad-spectrum antiviral treatment. It operates by raising the genomic mutation rate to the point that the deleterious load causes the population to decline. Its use has been limited to RNA viruses because of their high intrinsic mutation rates. Microbes with DNA genomes, which include many viruses and bacteria, have not been considered for this type of treatment because their low intrinsic mutation rates seem difficult to elevate enough to cause extinction. Surprisingly, models of lethal mutagenesis indicate that bacteria may be candidates for lethal mutagenesis. In contrast to viruses, bacteria reproduce by binary fission, and this property ensures their extinction if subjected to a mutation rate >0.69 deleterious mutations per generation. The extinction threshold is further lowered when bacteria die from environmental causes, such as washout or host clearance. In practice, mutagenesis can require many generations before extinction is achieved, allowing the bacterial population to grow to large absolute numbers before the load of deleterious mutations causes the decline. Therefore, if effective treatment requires rapid population decline, mutation rates >>0.69 may be necessary to achieve treatment success. Implications for the treatment of bacteria with mutagens, for the evolution of mutator strains in bacterial populations, and also for the evolution of mutation rate in cancer are discussed.
منابع مشابه
Bacterial and mammalian DNA alkyltransferases sensitize Escherichia coli to the lethal and mutagenic effects of dibromoalkanes.
Here we confirm and extend our previous studies demonstrating that the mutagenic potency of 1,2-dibromoethane (DBE) and dibromomethane (DBM) is markedly enhanced (not prevented) in bacteria expressing the O6-alkylguanine-DNA alkyltransferase (ATase) encoded by the Escherichia coli ogt gene. We demonstrate that, in close parallel with mutagenesis, the Ogt ATase sensitizes the bacteria to the let...
متن کاملConstruction of a recombinant vector for site-directed mutagenesis in Salmonella typhimurium
BACKGROUND: Among all common techniques in sitedirectedmutagenesis, λ Red recombinase system has beenwidely used to knock out chromosomal genes in bacteria. In thismethod, there is always the risk of DNA Linear digestion byhost's restriction enzymes that leads to the low frequency ofrecombination. OBJECTIVES:To overcome this, we constructeda recombinant vector to disrupt phoP gene in Salmonella...
متن کاملMutation Induced Extinction in Finite Populations: Lethal Mutagenesis and Lethal Isolation
Reproduction is inherently risky, in part because genomic replication can introduce new mutations that are usually deleterious toward fitness. This risk is especially severe for organisms whose genomes replicate "semi-conservatively," e.g. viruses and bacteria, where no master copy of the genome is preserved. Lethal mutagenesis refers to extinction of populations due to an unbearably high mutat...
متن کاملTheory of lethal mutagenesis for viruses.
Mutation is the basis of adaptation. Yet, most mutations are detrimental, and elevating mutation rates will impair a population's fitness in the short term. The latter realization has led to the concept of lethal mutagenesis for curing viral infections, and work with drugs such as ribavirin has supported this perspective. As yet, there is no formal theory of lethal mutagenesis, although referen...
متن کاملThe Yeast Environmental Stress Response Regulates Mutagenesis Induced by Proteotoxic Stress
Conditions of chronic stress are associated with genetic instability in many organisms, but the roles of stress responses in mutagenesis have so far been elucidated only in bacteria. Here, we present data demonstrating that the environmental stress response (ESR) in yeast functions in mutagenesis induced by proteotoxic stress. We show that the drug canavanine causes proteotoxic stress, activate...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Genetics
دوره 180 2 شماره
صفحات -
تاریخ انتشار 2008