RESUMO
The summarized experimental data on ombrophilic bacteria isolated from dystrophic waters formed by a mycobacterial community during the process of spruce wood decomposition are presented. It was demonstrated that the ombrophilic microbial community was characterized by wide phylogenetic diversity at the initial stage of spruce wood decomposition by xylotrophic fungi under low mineralization conditions. It was noted that bacteria were able to grow under acidic and ultrafresh conditions and most of them were referred to oligotrophs. It was determined that all isolated ombrophilic bacteria divided into three groups depending on the substrate specifity: saccharolytic, acidotrophic bacteria, and bacteria, which used C1-compounds as the substrate. The position of the ombrophilic bacteria in the trophic chain was determined.
Assuntos
Bactérias/metabolismo , Consórcios Microbianos , Madeira/microbiologia , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/genética , Bactérias/isolamento & purificação , Carbono/metabolismo , Celulose/metabolismo , Ecossistema , Hidrólise , Filogenia , Cloreto de Sódio/metabolismo , Cloreto de Sódio/farmacologia , Madeira/metabolismoRESUMO
We report draft genome sequences of two pyrazinamide (PZA)-resistant isolates, Mycobacterium tuberculosis 13-4152 and 13-2459. Isolate 13-4152 is PZA resistant, though it lacks mutations in known genes of PZA resistance. The comparative analysis of these genomes with those stored in GenBank revealed unique mutations, which may elucidate new mechanisms of PZA resistance.
RESUMO
This review describes and summarizes the data of ESX secretory system peculiarities characteristic of mainly mycobacteria. This system is involved in the secretion of small proteins of the WXG100 family. Some of these proteins represent virulence factors of Mycobacterium tuberculosis and other pathogenic mycobacteria. The role of these proteins in pathogenesis apparently consists of protecting mycobacteria from lysis in the macrophages that absorb them; the cytolysis of macrophages; and, hence, mycobacterium output into the surrounding tissue. A number of proteins that make up this secretory system are homologs of proteins involved in the conjugation process in saprophytic Mycobacterium smegmatis.
Assuntos
Proteínas de Bactérias/genética , Genes Bacterianos , Mycobacterium/genética , Antígenos de Bactérias/genética , Exocitose/genética , Macrófagos/imunologia , Macrófagos/microbiologia , Mycobacterium/imunologia , Mycobacterium/metabolismo , Mycobacterium/patogenicidade , Mycobacterium smegmatis/genética , Virulência/genéticaRESUMO
The review summarizes the data on the Mycobacterium tuberculosis mutations that lead to multidrug resistance (MDR) to various antibiotics. MDR strains arose over the past 30 years as a variety of antituberculosis drugs were introduced in medicine, and they largely discount the results of chemotherapy for tuberculosis. The most dangerous of them are strains with extensive drug resistance (XDR), which are resistant to four or five different drugs on average. The molecular mechanisms that make a strain resistant are considered. XDR and MDR strains result from successive and usually independent resistance mutations, which arise in various regions of the mycobacterial genome. In addition, the formation of resistant strains is affected by the phenomenon of tolerance and mycobacterial latency in infected tissues.
