The Clostridium perfringens alpha-toxin has previously been implicated as the major virulence factor in necrotic enteritis in chickens, although definitive proof has not been reported. In this study an alpha-toxin mutant was constructed in a virulent chicken isolate and shown to retain full virulence in a chicken disease model. These results demonstrated that alpha-toxin is not an essential vir...

Helicobacter pylori (H. pylori) infection has been reported in more than half of the world human population. It is associated with gastric inflammation and noticeable infiltration of the immune cells to the stomach mucosa by several cytokines secretion. IL-1&beta, IL-18 have been shown to contribute to H. pylori induced gastritis, but the details of inflammation and association of virulence fac...

The virulence factor concept has been a powerful engine in driving research and the intellectual flow in the fields of microbial pathogenesis and infectious diseases. This review analyzes virulence factors from the viewpoint of the damage-response framework of microbial pathogenesis, which defines virulence factor as microbial components that can damage a susceptible host. At a practical level,...

In this study, a number of 85 Staphylococcus aureus isolates were collected from various clinical sources including diabetic foot, burns, urine, wound, abcesses, boils, nasal discharge and vaginal smear from 135 inpatients at different Mansoura hospitals, Dakahlia governorate, Egypt. Isolates were phenotypically investigated for some virulence factors (biofilm, lipase, protease, staphylokinase ...

background : helicobacter pylori ( h. pylori ) infection is known as a major etiologic factor for a variety of gastroduodenal diseases. in iran, with a high rate of h. pylori infection close to 90%, numerous studies have revealed many aspects of interaction between the bacterium, mucosal surface and induction of disease outcome. the organism is genetically diverse and several virulence factors ...

The aim of this study was to investigate the phenotypic and genotypic characteristics of Streptococcus uberis isolated from subclinical mastitis (SCM) cases, and to examine the possible association between both characteristics. A total of 32 S. uberis were isolated from 772 quarter milk samples (SCM > 250,000 cells/ml) collected from 195 cows selected randomly from 18 dairy farms located in Arg...

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...