In an effort to understand what limits the virulence of malaria parasites, we infected inbred mice of three genotypes (C57Bl/6J, CBA/Ca and DBA/2) with one of two parasite lines of the rodent malaria Plasmodium chabaudi. One of these parasite lines had been serially passaged through C57Bl/6J mice and had evolved higher asexual growth rate, virulence and transmission in the process. The other pa...

conclusions the trat gene and pai markers were highly prevalent among upec strains isolated from patients in kashan, iran; therefore these determinants could be used as targets for prophylactic interventions. also there was a high level of resistance against the antibiotics commonly used for urinary tract infection treatment. to reach better therapeutic outcomes, treatment regimens have to be m...

to isolate and detect anthrax spores form soil in different regions of iran in order to find the anthrax foci‚ a total of 668 environmental specimens were collected during 2003-2004. bacterial endospores were extracted from soil specimens via flotation in distilled water, incubation at room temperature, filtration, heat shock and culture on blood agar and selective plet media. bacillus anthraci...

Integration of the Salmonella typhimurium virulence plasmid into the chromosome reduces mouse virulence, serum resistance, and HeLa cell adhesion-invasion while prolonging lag time in minimal medium. The proposed virulence plasmid regulatory element, rsk, partially restores virulence and fully restores the other three phenotypes to wild-type levels. Plasmid curing reduces virulence without affe...

UNLABELLED Previous work has shown that environmental and clinical isolates of Aspergillus fumigatus represent a diverse population that occupies a variety of niches, has extensive genetic diversity, and exhibits virulence heterogeneity in a number of animal models of invasive pulmonary aspergillosis (IPA). However, mechanisms explaining differences in virulence among A. fumigatus isolates rema...

Virulence, defined as damage to the host, is a trait of pathogens that evolutionary theory suggests benefits the pathogen in the "struggle for existence". Pathogens employ virulence mechanisms that contribute to disease. Central to the evolution of virulence of the infectious agents causing an array of bacterial disease is the evolutionary acquisition of type III secretion, a macromolecular com...

BACKGROUND Vibriosis is one of the most ubiquitous fish diseases caused by bacteria belonging to the genus Vibrio such as Vibrio (Listonella) anguillarum. Despite a lot of research efforts, the virulence factors and mechanism of V. anguillarum are still insufficiently known, in part because of the lack of standardized virulence assays. METHODOLOGY/PRINCIPAL FINDINGS We investigated and compar...

SUMMARY The costs and benefits of parasite virulence are analyzed in an Evolutionarily Stable Strategy (ESS) model. Increased host mortality caused by disease (virulence) reduces a parasite's fitness by damaging its food supply. The fitness costs of high virulence may be offset by the benefits of increased transmission or ability to withstand the host's defenses. It has been suggested that mult...

Background & Aims: Pseudomonas aeruoginosa is an opportunistic pathogen and an important cause of nosocomial infections. Different factors are involved in the pathogenicity of this bacterium. This study was performed to compare some factors associated with the virulence of clinical and environmental isolates of P. aeruoginosa. Methods: The present study was performed on 25 environmental isolate...