SIR-Uptake of avirulent T. pallidum (Nichols strain) was demonstrated in an in vitro system. Motile treponemes were harvested after culture for 7 days in spirolate broth (Izzat, Knox, and Wende, 1971). Non-motile treponemes were also obtained by keeping some of these at 4°C. for 18 hours. Macrophages were obtained from the peritoneal cavity of a rabbit bywashing with 100 ml. Hanks's balanced sa...

An avirulent and a virulent strain of Mycobacterium avium were selected on the basis of their growth patterns in human monocyte-derived macrophages. The virulent 7497 M. avium grew progressively in untreated macrophages, whereas the avirulent LR/149 M. avium was killed to a moderate extent by untreated human macrophages (50% of the original infectious inoculum killed 7 days after infection). We...

Ca(2+) rise and nitric oxide (NO) generation are essential early steps in plant innate immunity and initiate the hypersensitive response (HR) to avirulent pathogens. Previous work from this laboratory has demonstrated that a loss-of-function mutation of an Arabidopsis (Arabidopsis thaliana) plasma membrane Ca(2+)-permeable inwardly conducting ion channel impairs HR and that this phenotype could...

Salicylic acid (SA) plays a central role in plant disease resistance, and emerging evidence indicates that auxin, an essential plant hormone in regulating plant growth and development, is involved in plant disease susceptibility. GH3.5, a member of the GH3 family of early auxin-responsive genes in Arabidopsis (Arabidopsis thaliana), encodes a protein possessing in vitro adenylation activity on ...

Ca rise and nitric oxide (NO) generation are essential early steps in plant innate immunity and initiate the hypersensitive response (HR) to avirulent pathogens. Previous work from this laboratory has demonstrated that a loss-of-function mutation of an Arabidopsis (Arabidopsis thaliana) plasma membrane Ca-permeable inwardly conducting ion channel impairs HR and that this phenotype could be resc...

Mitogen-activated protein (MAP) kinase cascades are readily activated during the response of plants to avirulent pathogens or to pathogen-derived elicitors. Here we show that the tomato MAP kinase LeMPK3 is specifically induced at the mRNA level during elicitation of the hypersensitive response in resistant plants infected by avirulent strains of the phytopathogenic bacteria Xanthomonas campest...

The change in gene expression patterns in response to host environments is a prerequisite for bacterial infection. Bacterial diseases often occur as an outcome of the complex interactions between pathogens and the host. The indigenous, usually non-pathogenic microflora is a ubiquitous constituent of the host. In order to understand the interactions between pathogens and the resident microflora ...

Random-bred ICR mice recovered from infection with avirulent Plasmodium yoelii were challenged at various later times with virulent P. yoelii or with another species of Plasmodium, P. berghei, to characterize the immunological nature of the long-term state of immunity generated in response to the avirulent infection. It was found that recovered mice resisted lethal challenge with virulent P. yo...

Preventing disease outbreaks in cultured turbot Psetta maxima L. caused by Aeromonas salmonicida subsp. salmonicida (ASS) requires a better understanding of how this pathogen colonizes its host. Distribution of 1 virulent and 2 avirulent ASS strains in turbot tissues was investigated during early and late stages of infection following an immersion challenge. To track bacteria within the turbot,...

Candida albicans is an opportunistic fungus responsible for the majority of systemic fungal infections. Multiple factors contribute to C. albicans pathogenicity. C. albicans strains lacking CaArv1 are avirulent. Arv1 has a conserved Arv1 homology domain (AHD) that has a zinc-binding domain containing two cysteine clusters. Here, we explored the role of the CaAHD and zinc-binding motif in CaArv1...