Comparison of DNA from virulent strains of bacterial pathogens with DNA from less virulent or avirulent close relatives allows the identification of those genomic regions that are present only in virulent strains. Such regions are often associated with pathogenicity islands (PIs) and their characterisation can lead to a greater understanding of the pathogenesis of infectious diseases. There is ...

The Arabidopsis NPR1 gene controls the onset of systemic acquired resistance (SAR), a plant immunity, to a broad spectrum of pathogens that is normally established after a primary exposure to avirulent pathogens. Mutants with defects in NPR1 fail to respond to various SAR-inducing treatments, displaying little expression of pathogenesis-related (PR) genes and exhibiting increased susceptibility...

In human patients, disseminated candidiasis, a life-threatening disease for immunocompromised patients, is often associated with intestinal lesions. In this study, we demonstrate that immunosuppressed gnotobiotic (IGB) piglets orally inoculated with wild-type Candida albicans developed extensive intestinal lesions and disseminated infection. Severe ulceration of the ileal mucosa was observed ov...

Antisera produced in rabbits immunized with an enteroinvasive O143 strain of Escherichia coli were absorbed with an avirulent derivative of the same strain. The resulting sera have been previously shown to recognize enteroinvasive pathogens when used in an enzyme-linked immunosorbent assay. In the current study, Western blots (immunoblots) showed that such an absorbed rabbit antiserum recognize...

In the course of conducting forensic analysis of human skeletal material, anthropologists are exposed to a number of biological and chemical hazards. This paper reviews the primary concerns in terms of infection or exposure. Handling of human tissue provides an avenue through which bloodborne pathogens may be transported. Scene recovery also includes a set of hazards through exposure to human, ...

The ability of potential pathogens to acquire iron in a host is an important determinant of both their virulence and the nature of the infection produced. Virulent gram-negative bacteria are capable of acquiring sufficient iron from the host because their virulence (for chick embryos) is unaffected by exogenous iron. Avirulent mutants which are apparently limited in their ability to acquire iro...

Plants activate distinct defense responses depending on the lifestyle of the attacker encountered. In these responses, salicylic acid (SA) and jasmonic acid (JA) play important signaling roles. SA induces defense against biotrophic pathogens that feed and reproduce on live host cells, whereas JA activates defense against necrotrophic pathogens that kill host cells for nutrition and reproduction...

Viral vaccine vectors have shown to be effective in inducing a robust immune response against the vaccine antigen. Newcastle disease virus (NDV), an avian paramyxovirus, is a promising vaccine vector against human and veterinary pathogens. Avirulent NDV strains LaSota and B1 have long track records of safety and efficacy. Therefore, use of these strains as vaccine vectors is highly safe in avia...

BACKGROUND Avirulent pathogens elicit a battery of plant defenses, often accompanied by collapse of the challenged cells. In soybean cells, sustained accumulation of H2O2 from an oxidative burst cues localized host cell death. Such hypersensitive cell death appears to be an active process, but little is known about the mechanisms underlying cellular collapse. RESULTS We show that H2O2 stimula...