By random transposon Tn5 insertions, we previously identified six virulence-associated SalI fragments, B, D, F, G, H, and P, in the 230-kilobase plasmid pMYSH6000 of Shigella flexneri 2a. In this study, we analyzed the sites of 134 independent Tn5 insertions on four contiguous SalI fragments, B, P, H, and D, of pMYSH6000 and identified five virulence-associated regions; four were associated wit...

A Leishmania model to explain microbial virulence in chronic infectious diseases is proposed. All these diseases progress from infection to symptomatic phase to host death or recovery. The outcome of each phase is depicted to result from the interactions of a distinct group of parasite molecules with a specific host immune compartment. The first group consists of invasive/evasive determinants, ...

Area-based strategies have been widely employed in efforts to improve population health and take action on social determinants of health (SDH) and health inequities, including in urban areas where many of the social, economic and environmental factors converge to influence health. Increasingly, these factors are recognized as being part of a complex system, where population health outcomes are ...

The attenuated Japanese encephalitis virus (JEV) strain SA14-14-2 has been successfully utilized to prevent JEV infection; however, the attenuation determinants have not been fully elucidated. The envelope (E) protein of the attenuated JEV SA14-14-2 strain differs from that of the virulent parental SA14 strain at eight amino acid positions (E107, E138, E176, E177, E264, E279, E315, and E439). H...

Phytopathogens coordinate multifaceted life histories and deploy stratified virulence determinants via complex, global regulation networks. We dissect the global regulation of four distantly related model phytopathogens to evaluate large-scale events and mechanisms that determine successful pathogenesis. Overarching themes include dependence on centralized cell-to-cell communication systems, pe...

Because human milk is thought to protect infants from shigellosis, we evaluated milk for immunoglobulin A to Shigella virulence determinants. Milk was preincubated to remove antibodies unrelated to each locus of interest, using defined Shigella and E. coli hybrids containing known Shigella genetic segments prior to immunoblotting. The milk could not be shown to contain antibodies to chromosomal...

Several environmental factors regulate the expression of virulence genes under certain conditions and the expression of bacterial virulence determinants. Cytolethal distending toxin (CDT) is an important virulence determinant secreted by Campylobacter jejuni (C. jejuni), a leading cause of gastrointestinal bacterial pathogen worldwide. Therefore, the aim of the study was to investigate the effe...