Pathogenic microorganisms possess antioxidant defense mechanisms for protection from reactive oxygen metabolites such as hydrogen peroxide (H202), which are generated during the respiratory burst of phagocytic cells. These defense mechanisms include enzymes such as catalase, which detoxify reactive oxygen species, and DNA repair systems which repair damage resulting from oxidative stress. To de...

An in vitro pharmacokinetic model was used to simulate the pharmacokinetics of trovafloxacin, ofloxacin, and ciprofloxacin in human serum and to compare their pharmacodynamics against eight Streptococcus pneumoniae strains. The MICs of ofloxacin and ciprofloxacin ranged from 1 to 2 micrograms/ml. Trovafloxacin was 8- to 32-fold more potent, with MICs of 0.06 to 0.12 microgram/ml. Logarithmic-ph...

Seven of eight plasmids of incompatibility group P were found to code for the capacity to propagate bacteriophage IKe in Escherichia coli. Six of the seven plasmids allowed propagation of IKe by one bacterial host (RG172) but not by another (RG176); the other plasmid allowed IKe propagation by both hosts. IKe propagation by a number of E. coli K-12 strains was quite variable. IKeh, an extended ...

We report a simple and efficient colorimetric method to screen large numbers of bacterial strains for UV- and X-radiation sensitivity. We used reference radiation-sensitive and control strains of Escherichia coli K-12 to compare our colorimetric method to a standard clonogenic plating method. Our colorimetric method was as accurate as the standard method and was superior in terms of savings in ...

Due to the serovar diversity in Haemophilus (H.) parasuis, it is difficult to develop a universal serological method for detection of this pathogen. Here, we report a universal plate-agglutination test for detecting H. parasuis. Diagnostic antisera were prepared by mixing antisera of serovars 4, 5, 12, 13 and 14 in the optimized ratio. The results of the plate-agglutination test showed that the...

In several Escherichia coli K-12 strains grown on a limiting concentration of glucose, isocitrate dehydrogenase (IDH) was inactivated about 90% after cessation of growth upon exhaustion of the glucose. Such inactivation has been previously observed in several E. coli strains but not in E. coli K-12 (unless acetate was added to the bacterial culture when growth ceased). IDH was inactivated 75 to...

fusarium wilt of chickpea, caused by f. oxysporum f. sp. ciceris, is one of the most important diseases of this plant in iran. in order to control this disease, fluorescent pseudomonads were isolated from the rhizosphere of chickpea plants in khorasan province by using king,s b medium (kb). antifungal activity of 80 bacterial strains against f. oxysporum f. sp. ciceris was evaluated on kb and p...

Over fifty bacterial strains were isolated from seawater samples in the presence of naphthalene as a sole source of carbon and energy. Among them, three isolates with higher growth rate and naphthalene degradation ability were selected for further studies. Biochemical and molecular analysis revealed that two Persian Gulf isolates, strain PG-10 and strain PG-48 belonged to the group of hydrocarb...

Background: Due to multiple drug resistance against antimicrobial drugs for treatment of infectious disease, investigations to discovering new antibacterial compounds from natural sources have been designated. Objective: According to antimicrobial effects of some Capparis species, this study was carried out to evaluate the antimicrobial activity of the extract and fractions of Capparis cart...