Photobacterium damselae subsp. damselae causes infections and fatal disease in marine animals and in humans. Highly hemolytic strains produce damselysin (Dly) and plasmid-encoded HlyA (HlyA(pl)). These hemolysins are encoded by plasmid pPHDD1 and contribute to hemolysis and virulence for fish and mice. In this study, we report that all the hemolytic strains produce a hitherto uncharacterized ch...

Escherichia coli alpha-hemolysin (HlyA), archetype of a bacterial pore-forming toxin, has been reported to deregulate physiological Ca2+ channels, thus inducing periodic low-frequency Ca2+ oscillations that trigger transcriptional processes in mammalian cells. The present study was undertaken to delineate the mechanisms underlying the Ca2+ oscillations. Patch-clamp experiments were combined wit...

The pore-forming hemolysin (HlyA) of Escherichia coli represents a unique class of bacterial toxins that require a posttranslational modification for activity. The inactive protoxin pro-HlyA is activated intracellularly by amide linkage of fatty acids to two internal lysine residues 126 amino acids apart, directed by the cosynthesized HlyC protein with acyl carrier protein as the fatty acid don...

AIM Aim of the study was to investigate the prevalence, virulence gene profiles, and antimicrobial resistance pattern of Shiga toxigenic Escherichia coli (STEC) in diarrheic buffalo calves from Andhra Pradesh and Telangana States. MATERIALS AND METHODS A total of 375 fecal samples from diarrheic buffalo calves of 1-7, 8-30, 31-60, and 61-90 days age were collected from which STEC were isolate...

The pore-forming hemolysin of Escherichia coli (HlyA), an important virulence factor in extraintestinal E. coli infections, causes thromboxane generation and related vasoconstriction in perfused rabbit lungs (Seeger, W., H. Walter, N. Suttorp, M. Muhly, and S. Bhakdi. 1989. J. Clin. Invest. 84:220). We investigated the influence of pulmonary vascular "priming" with endotoxin on the responsivene...

background cholera is a severe diarrheal illness caused by vibrio cholerae, which produces a virulence factor named el tor hemolysin encoded by the hlya gene. objectives this study meant to analyze the phenotypic characteristics and presence of hlya gene in v. cholerae isolated from patients in iran. the hlya gene which codes for hemolysin, plays an essential role in manifestation of cholera ,a...

A pair of primers targeting the hlyA gene for Vibrio cholerae which could distinguish the classical from El Tor biotypes was designed and combined with other specific primers for ompW, rfb complex, and virulence genes such as ctxA, toxR, and tcpI in a multiplex PCR (m-PCR) assay. This m-PCR correctly identified 39 V. cholerae from clinical, water and seafood samples. The efficiency of this mult...

alpha-hemolysin (HlyA) is an extracellular protein toxin secreted by Escherichia coli that acts at the level of plasma cell membranes of target eukaryotic cells. Previous studies showed that toxin binding to the bilayers occurs in at least two ways, a reversible adsorption and an irreversible insertion. Studies of HlyA insertion into bilayers formed from phosphatidylcholine show that insertion ...

Urinary tract infections (UTIs) are among the most common bacterial infections, causing considerable morbidity in females. Infection is highly recurrent despite appropriate antibiotic treatment. Uropathogenic Escherichia coli (UPEC), the most common causative agent of UTIs, invades bladder epithelial cells (BECs) and develops into clonal intracellular bacterial communities (IBCs). Upon maturati...

α-Hemolysin (HlyA) from Escherichia coli is considered as the prototype of a family of toxins called RTX (repeat in toxin), a group of proteins that share genetic and structural features. HlyA is an important virulence factor in E. coli extraintestinal infections, such as meningitis, septicemia and urinary infections. High concentrations of the toxin cause the lysis of several cells such as ery...