Phenotypic diversity is critical to the lifestyles of many microbial species, enabling rapid responses to changes in environmental conditions. In the human fungal pathogen Candida albicans, cells exhibit heritable switching between two phenotypic states, white and opaque, which yield differences in mating, filamentous growth, and interactions with immune cells in vitro. Here, we address the in ...

The study of freshly isolated cultures is necessary to form an objective idea the properties plague microbe natural populations. analysis levels investigating strains has been carried out and characteristics Yersinia pestis in Kazakhstan are presented. results studying phenotypic genetic provided. Following epizootiological survey foci, museums live at control stations annually receive pathogen...

Genetic variation among isolates of Escherichia coli O111 obtained mostly from patients with diarrhea in Brazil was assessed by multilocus enzyme electrophoresis to characterize chromosomal genotypes and by gene probes and adherence assays to characterize virulence properties. Among the 152 isolates, we resolved 16 distinct electrophoretic types (ETs), which differed on average at 40% of the en...

To cause disease, influenza virus must possess several genetically determined abilities that mediate stages in pathogenesis. The virulent mouse-adapted variant A/FM/1/47-MA (FM-MA), derived from the avirulent A/FM/1/47 (FM) strain, had acquired mutations in genes that control virulence. The purpose of this study was to identify those genes that had mutated to result in increased virulence and t...

One of the hypotheses invoked to explain the occurrence of different diseases associated with dengue virus infection is that dengue viruses differ in virulence properties. Observations on virologically studied dengue fever and dengue hemorrhagic fever (DHF)"'8 patients have reasonably established that both of these diseases are associated with dengue viruses of all known antigenic types. The po...

UNLABELLED Streptococcal surface dehydrogenase (SDH) (glyceraldehyde-3-phosphate dehydrogenase [GAPDH]) is an anchorless major multifunctional surface protein in group A Streptococcus (GAS) with the ability to bind important mammalian proteins, including plasmin(ogen). Although several biological properties of SDH are suggestive of its possible role in GAS virulence, its direct role in GAS path...

Strains of Staphylococcus aureus, an important human pathogen, display up to 20% variability in their genome sequence, and most sequence information is available for human clinical isolates that have not been subjected to genetic analysis of virulence attributes. S. aureus strain Newman, which was also isolated from a human infection, displays robust virulence properties in animal models of dis...

The association of axenically grown trophozoites of Entamoeba histolytica strains HK-9 or HM-1:IMSS with various types of gram-negative bacteria for relatively short periods markedly increased their virulence, as evidenced by their ability to destroy monolayers of tissue-cultured cells. Interaction of trophozoites with bacteria that were heat inactivated, glutaraldehyde fixed, or disrupted by s...