ArdB proteins are known to inhibit the activity of the type I restriction-modification (RM-I) system, in particular EcoKI (IA family). The mechanism of ArdB's activity still remains unknown; the spectrum of targets inhibited has been poorly studied. In this work, it was shown that the presence of the ardB gene from the R64 plasmid could suppress the activity of EcoAI endonuclease (IB family) in Escherichia coli TG1 cells. Due to the absence of specificity of ArdB to a certain RM-I system (it inhibits both the IA- and IB-family), it can be assumed that the mechanism of the anti-restriction activity of this protein does not depend on the sequence DNA at the recognition site nor the structure of the restriction enzyme of the RM-I systems.

• MeSH
• DNA MeSH
• Escherichia coli * genetika   metabolismus   MeSH
• plazmidy genetika   MeSH
• proteiny z Escherichia coli * genetika   chemie   MeSH
• restrikční enzymy genetika   MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH

Green tea polyphenols (GTP) are widely believed to function as antioxidants and antimicrobial agents. Here we observed that GTP and epigallocatechin gallate, the most abundant catechin in GTP, could also function as prooxidants and produce hydrogen peroxide (H2O2) to inhibit the growth of Pseudomonas aeruginosa. pH value of the medium was the key factor that affected prooxidant versus antioxidant property of GTP. Under weakly acidic conditions (pH 5.5-6.5), GTP showed antioxidant activity by eliminating H2O2; whereas, under neutral and weakly alkaline conditions (pH 7.0-8.0), GTP showed prooxidant activity and inhibited the growth of P. aeruginosa. Furthermore, we studied the effects of GTP on gene expression profiles of a few oxidative stress-related genes by quantitative real-time PCR analysis. After 10 min to 1 h of exposure under weakly alkaline condition, GTP significantly up-regulated expression levels of katB, sodM, ohr, lexA, and recN gene. These findings highlight that the pH-dependent H2O2 production by GTP contributes to the antibacterial activity and can induce oxidative stress-related responses in P. aeruginosa.

• MeSH
• antibakteriální látky farmakologie   MeSH
• antioxidancia farmakologie   MeSH
• bakteriální proteiny genetika   metabolismus   MeSH
• čaj chemie   MeSH
• katechin analogy a deriváty   farmakologie   MeSH
• koncentrace vodíkových iontů MeSH
• kvantitativní polymerázová řetězová reakce MeSH
• oxidační stres účinky léků   MeSH
• peroxid vodíku analýza   metabolismus   MeSH
• polyfenoly analýza   farmakologie   MeSH
• Pseudomonas aeruginosa účinky léků   růst a vývoj   MeSH
• reaktivní formy kyslíku analýza   farmakologie   MeSH
• restrikční enzymy genetika   metabolismus   MeSH
• rostlinné extrakty analýza   farmakologie   MeSH
• serinové endopeptidasy genetika   metabolismus   MeSH
• upregulace MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Genome predictions based on selected genes would be a very welcome approach for taxonomic studies. We analyzed three genes, recN, flaA, and ftsY, for determining if these genes are useful tools for systematic analyses in the genus Anoxybacillus. The genes encoding a DNA repair and genetic recombination protein (recN), the flagellin protein (flaA), and GTPase signal docking protein (ftsY) were sequenced for ten Anoxybacillus species. The sequence comparisons revealed that recN sequence similarities range between 61% and 99% in the genus Anoxybacillus. Comparisons to other bacterial recN genes indicated that levels of similarity did not differ from the levels within genus Anoxybacillus. These data showed that recN is not a useful marker for the genus Anoxybacillus. A 550-600-bp region of the flagellin gene was amplified for all Anoxybacillus strains except for Anoxybacillus contaminans. The sequence similarity of flaA gene varies between 61% and 76%. Comparisons to other bacterial flagellin genes obtained from GenBank (Bacillus, Pectinatus, Proteus, and Vibrio) indicated that the levels of similarity were lower (3-42%). Based on these data, we concluded that the variability in this single gene makes it a particularly useful marker. Another housekeeping gene ftsY suggested to reflect the G+C (mol/mol) content of whole genome was analyzed for Anoxybacillus strains. A mean difference of 1.4% was observed between the G+C content of the gene ftsY and the G+C content of the whole genome. These results showed that the gene ftsY can be used to represent whole G+C content of the Anoxybacillus species.

• MeSH
• Anoxybacillus chemie   klasifikace   genetika   izolace a purifikace   MeSH
• bakteriální proteiny chemie   genetika   MeSH
• flagelin chemie   genetika   MeSH
• fylogeneze MeSH
• molekulární sekvence - údaje MeSH
• receptory cytoplazmatické a nukleární chemie   genetika   MeSH
• restrikční enzymy chemie   genetika   MeSH
• sekvence nukleotidů MeSH
• sekvenční homologie nukleových kyselin MeSH
• zastoupení bazí MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Two hundred eighty-four isolates of enterococci from feces of wild living chamois from alpine environments were tested for sensitivity to three antibiotics. Low frequency of resistance was observed in studied enterococcal populations (about 5 % for tetracycline and erythromycin and 0 % for ampicillin). In six animals, the population of enterococci lacked any detectable resistance. Our data indicated that enterococcal population in feces of the majority of studied animals did not encounter mobile genetic elements encoding antibiotic resistance probably due to spatial separation and/or due to low exposure to the antibiotics. Based on resistance profiles observed, three populations were analyzed for the presence of restriction endonucleases. The restriction enzymes from two isolates-31K and 1K-were further purified and characterized. Restriction endonuclease Efa1KI recognizes CCWGG sequence and is an isoschizomer of BstNI. Endonuclease Efc31KI, a BsmAI isoschizomer, recognizes the sequence GTCTC and it is a first restriction endonuclease identified in Enterococcus faecium. Our data indicate that restriction-modification (R-M) systems do not represent an efficient barrier for antibiotic resistance spreading; enterococcal populations colonized by antibiotics resistance genes were also colonized by the R-M systems.

• MeSH
• antibakteriální látky farmakologie   MeSH
• bakteriální léková rezistence MeSH
• bakteriální proteiny chemie   genetika   metabolismus   MeSH
• Enterococcus účinky léků   enzymologie   genetika   izolace a purifikace   MeSH
• feces mikrobiologie   MeSH
• mikrobiální testy citlivosti MeSH
• restrikční enzymy chemie   genetika   metabolismus   MeSH
• Rupicapra mikrobiologie   MeSH
• substrátová specifita MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• MeSH
• delece genu MeSH
• DNA fingerprinting MeSH
• finanční podpora výzkumu jako téma MeSH
• genomika statistika a číselné údaje   MeSH
• inzerční mutageneze genetika   statistika a číselné údaje   MeSH
• restrikční enzymy genetika   MeSH
• sekvenční homologie MeSH
• Treponema pallidum genetika   MeSH

• MeSH
• bakteriální proteiny genetika   metabolismus   MeSH
• bodová mutace MeSH
• restrikční enzymy genetika   MeSH
• teplota MeSH

• MeSH
• Acinetobacter genetika   izolace a purifikace   metabolismus   MeSH
• DNA bakterií analýza   diagnostické užití   genetika   MeSH
• fenotyp MeSH
• genotyp MeSH
• lidé MeSH
• restrikční enzymy analýza   diagnostické užití   genetika   MeSH
• techniky typizace bakterií klasifikace   MeSH
• Check Tag
• lidé MeSH
• Geografické názvy
• Česká republika MeSH

• MeSH
• gramnegativní anaerobní bakterie enzymologie   MeSH
• molekulární sekvence - údaje MeSH
• přežvýkavci mikrobiologie   MeSH
• restrikční enzymy genetika   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH

• MeSH
• genetické markery MeSH
• restrikční enzymy genetika   MeSH
• rostliny genetika   MeSH
• Publikační typ
• přehledy MeSH