The genes encoding the heat-labile toxin of Escherichia coli were isolated by recombinant DNA methods from enterotoxigenic E. coli recovered from a human and a piglet with diarrhea. With restriction endonucleases, a fine-structure map was made for the toxin genes. Both genes were found to be highly homologous within the toxin-coding DNA, but the surrounding DNA sequences were found to be quite ...

A novel gene that regulates the alpha-toxin (plc), kappa-toxin (colA), and theta;-toxin (pfoA) genes was identified using toxin-negative mutant strains of Clostridium perfringens. The cloned 3.2-kb fragment contained the virX gene encoding a 51-amino acid polypeptide of unknown function that seemed to be responsible for the activation of toxin genes. The virX knock out mutant of wild-type strai...

To estimate the prevalence of Shiga toxin producing Escherichia coli in Australia, bloody stool samples from two Australian locations were screened for the presence of Shiga toxin genes, stx1 and stx2. Four of 126 (3.2%) and 139 of 5,829 (2.4%) patients from the two locations had a positive polymerase chain reaction for Shiga toxin genes.

The aim of this study was to identify virulent Shiga toxin-producing Escherichia coli (STEC) strains isolated from faecal samples of 100 clinically healthy calves. In the present study, a total of 100 Escherichia coli (E. coli) isolates from clinically healthy calves belonging to 6 different farms located in Khorasan Razavi province, Iran, were examined for presence of virulence genes character...

Fish venom remains a virtually untapped resource. There are so few fish toxin sequences for reference, which increases the difficulty to study toxins from venomous fish and to develop efficient and fast methods to dig out toxin genes or proteins. Here, we utilized Chinese yellow catfish (Pelteobagrus fulvidraco) as our research object, since it is a representative species in Siluriformes with i...

The Clostridium perfringens ε-toxin is an extremely potent toxin associated with lethal toxemias in domesticated ruminants and may be toxic to humans. Intoxication results in fluid accumulation in various tissues, most notably in the brain and kidneys. Previous studies suggest that the toxin is a pore-forming toxin, leading to dysregulated ion homeostasis and ultimately cell death. However, mam...

background and objectives: shiga toxin-producing escherichia coli ( stec) have emerged as human pathogens and contamination of foods of animal origin has been a major public health concern. the aim of the present study was to determine the dissemination of stec in healthy and diarrheic calves in urmia region which is located in west azerbaijan province, iran. materials and methods: in the curre...

Paralytic shellfish poisoning (PSP) is a human foodborne syndrome caused by the consumption of that accumulate paralytic toxins (PSTs, saxitoxin group). In PST-producing dinoflagellates such as Alexandrium spp., toxin synthesis encoded in nuclear genome via gene cluster ( sxt ). Toxin production supposedly associated with presence 4th domain sxtA sxtA4 ), one core genes PST cluster. It postulat...

Lysinibacillus sphaericus produces the mosquito larvicidal binary toxin consisting of BinA and BinB, which are both required for toxicity against Culex and Anopheles larvae. The molecular mechanisms behind Bin toxin-induced damage remain unexplored. We used whole-genome microarray-based transcriptome analysis to better understand how Culex larvae respond to Bin toxin treatment at the molecular ...

Scorpion venom is the richest source of peptide toxins with high levels of specific interactions with different ion-channel membrane proteins. The present study involved the amplification and sequencing of a 310-bp cDNA fragment encoding a beta-like neurotoxin active on sodium ion-channel from the venom glands of scorpion Androctonus crassicauda belonging to the Buthidae family using r...