Chemical extraction and analysis ofreaction mixtures of preparations of staphylococcal alpha toxin and human plasma ~-lipoproteln (HDL) indicated that the cholesteryl esters which form an integral part of the lipoprotein molecules were de-esterified by the toxin preparations with no apparent destruction of the cholesterol moiety° This report is the first of cholesterol esterase produced by stap...

Abstract Background Bladder melanosis is rare. It has previously been described only in the fifth decade of life or beyond; it not childhood. Previous descriptions have generally case reports, and so natural history poorly understood. Urinary symptoms present at time cystoscopy frequently attributed to bladder melanosis. A possible suggested aetiology aberrant migration melanocyte during embryo...

t-2 toxin is the most poisonous trichothecene produced by fusarium species especially f.sporotrichioides . t-2 toxin is a biological contaminant in a number of agricultural commodities that can cause severe diseases among humans and animals and even lead to death. the aim of the current study is the analysis of t-2 mycotoxin in fusarium species by high-performance liquid chromatography (hplc) c...

Botulinum neurotoxins are natural molecules produced by anaerobic spore-forming bacteria called Clostradium boltulinum. The toxin has a peculiar mechanism of action by preventing the release of acetylcholine from the presynaptic membrane. Consequently, it has been used in the treatment of various neurological conditions related to muscle hyperactivity and/or spasticity. Also, it has an impact o...

Shiga toxin-producing Escherichia coli (STEC) are important enteric pathogens worldwide, causing diarrhea with or without blood visibly present and hemolytic uremic syndrome. STEC are unique among diarrheogenic E coli in producing Shiga toxin type 1 and type 2, the virulence factors responsible for bloody diarrhea and hemolytic uremic syndrome. Cattle and other ruminants are the natural reservo...

Delta-toxin produced by Clostridium perfringens types B and C is a β-pore-forming cytotoxin. Here, using site-directed mutagenesis, we identified the amino acid residues that contribute to delta-toxin oligomerization binding. We replaced Lys-43 Ser-109 located in β-sandwich domain Arg-200 rim domain. Substitution of alanine for caused reductions both cytotoxicity oligomerization. However, excha...

background : clostridium perfringens type c strains cause severe necrotizing enteritis in sheep, calves, goats, pigs and humans. beta-toxin is introduced to be the essential virulence factor of this microorganism. in the present study, a new method was established for the purification of beta toxin from culture supernatant fluid of c. perfringens type c vaccinal strain. methods : the four steps...