Pathogenicity islands are sets of successive genes in a genome that determine the virulence of a bacterium. In a growing number of studies, bacterial virulence appears to be determined by multiple islands scattered along the genome. This is the case in a family of seven plant pathogens and a human pathogen that, under KdgR regulation, massively secrete enzymes such as pectinases that degrade pl...

Staphylococci of the albus and aureus varieties have long been known to inhabit the human vaginal tract in health as well as in disease, and various roles have been attributed to them in the causation of certain types of disease of the female genitalia. Thus, Staphylococcus aureus of the vagina has been considered the causative agent in some cases of puerperal fever, but on the whole these orga...

Controlled exposure experiments can be very informative, however, they are based on the assumption that pathogens maintained on artificial media under long-term storage retain the infective and pathogenic properties of the reproducing pathogen as it occurs in a host. We observed that JEL284, an in vitro cultured and maintained isolate of Batrachochytrium dendrobatidis (Bd), was becoming less in...

cytospora dieback and canker disease is one of prevalent disease of walnut trees in iran caused by several species of cytospora genus. the aim of this study was to determination of virulence degree in 58 isolates of dominant species, cytospora chrysosperma. isolates from 12 provinces of iran; hamedan, kurdistan, kermanshah, ilam, west azarbaijan, zanjan, markazi, lorestan, chaharmahal va bakhti...

Rickettsiae are obligate intracellular parasitic bacteria that cause febrile exanthematous illnesses such as Rocky Mountain spotted fever, Mediterranean spotted fever, epidemic, and murine typhus, etc. Although the vector ranges of each Rickettsia species are rather restricted; i.e., ticks belonging to Arachnida and lice and fleas belonging to Insecta usually act as vectors for spotted fever gr...