RESUMEN
Drug-resistant (including multidrug-resistant) bacteria increase continuously with the wide use of antibiotics, which have seriously threatened the human health. It is an important way to fight against drug-resistance by screening and developing novel drugs based on the various mechanisms of the bacterial drug tolerances. Meanwhile, the basic research related to the new drug R. & D. and studies on the new screening methods for the antimicrobial agents should be taken seriously and strengthened, so as to accelerate the process of finding new drugs and meet the challenge of new pathogens and new drug-resistant strains.
Asunto(s)
Humanos , Antibacterianos , Farmacología , Bacterias , Genética , Fenómenos Fisiológicos Bacterianos , Diseño de Fármacos , Evaluación Preclínica de Medicamentos , Farmacorresistencia Bacteriana Múltiple , Genética , Fisiología , PéptidosRESUMEN
<p><b>OBJECTIVE</b>To establish an efflux pump inhibitor screening model with the out-membrane protein OprM in Pseudomonas aeruginosa efflux pump system as the target point.</p><p><b>METHODS</b>Efflux pump out-membrane protein gene oprM was obtained from standard Pseudomonas aeruginosa PA01 strain. Expression of OprM protein was induced in E. coli strain HS151 with T-easy vector as the cloning vector, and pMMB67EH as the expression vector. In order to evaluate the function of OprM protein, we measured intracellular tetracycline concentrations with liquid scintillation counter, measured the diameters of bacteriostatic circles with paper disc, and then established a screening model accordingly.</p><p><b>RESULTS</b>OprM protein was highly expressed. Using Pseudomonas aeruginosa as the main detecting bacteria, we established a drug screening model acting on OprM. A total of 1 600 microbial fermentation samples were screened with this model, among which 56 positive strains were found, with a positive rate of 3.5%.</p><p><b>CONCLUSION</b>OprM plays an important role in drug efflux. The established model has good specificity and maneuverability.</p>
Asunto(s)
Humanos , Antibacterianos , Metabolismo , Farmacología , Proteínas de la Membrana Bacteriana Externa , Genética , Proteínas Bacterianas , Genética , Evaluación Preclínica de Medicamentos , Métodos , Farmacorresistencia Microbiana , Resistencia a Múltiples Medicamentos , Genética , Escherichia coli , Genética , Proteínas de Transporte de Membrana , Genética , Plásmidos , Genética , Pseudomonas aeruginosa , GenéticaRESUMEN
The lineage-Actinobacteria class nov.comprises organisms with a DNA base composition which generally is above 50% G+C (with a few exceptions).We set up a method that has been used in isolating Actinobacteria and Actinomycetes. We added 25?g/mL Nalidixic acid and 25?g/mL Aztreonam into isolation media to inhibit the other bacteria and 20?g/mL Benlete to inhibit fungi.We used fluorescent in situ hybridization to identi 1fy Actinobacteria. Using the four probes,PA-1,PA-2,PHGC and PNHGC,we made the identification on the 31 strains of the 56 gram-positive bacteria randomly selected and got 22 positive results,6 negative results and 3 ambiguous results.It was showed that the results of G+C content determination and FISH method were identical.Among 31 strain,there were 24 strains of Actinobacteria,the rate was 77.4%.This proved the isolation and FISH identification methods were effective and reliable.