Laboratory grazing experiments compared ingestion of two subclones of the dinoflagellate Alexandrium lusitanicum by gastropod veliger larvae (Nassarius sp.). While the two prey subclones originated from the same monoclonal isolate of A. lusitanicum, one possessed the ability to produce paralytic-shellfish-poisoning toxins (PSTs), while the other did not. Ingestion rates on the two Alexandrium s...

We describe a mutant derived from Chinese hamster ovary cells that is offt-sensitive for viability and for resistance to certain protein toxins. This mutant, termed G.7.1, grows normally at 34 degrees C but does not grow in Dulbecco's modified Eagle's medium at 39.5 degrees C. However, when this medium is supplemented with FeSO4, the mutant cells will grow at the elevated temperature. At 39.5 d...

Type II toxin-antitoxin (TA) systems are generally composed of two genes organized in an operon, encoding a labile antitoxin and a stable toxin. They were first discovered on plasmids where they contribute to plasmid stability by a phenomenon denoted as 'addiction', and subsequently in bacterial chromosomes. To discover novel families of antitoxins and toxins, we developed a bioinformatics appr...

A multiplex PCR system was developed for specific identification of genes encoding heat-labile (LTI) and heat-stable (STI and STII) toxins of enterotoxigenic Escherichia coli (ETEC) strains. In addition, primers specific for the E. coli gene coding for 16S rRNA were used as an internal control of the DNA amplification. The specificity of the method was validated by single PCR tests performed wi...

An alkaline phosphatase-labeled oligonucleotide DNA probe (CTAP) that was specific for the cholera toxin gene (ctxA) was identified. All cholera toxin-producing strains of Vibrio cholerae, regardless of serotype, hybridized with the CTAP probe, while nontoxigenic strains from either environmental sources or from deletion or substitution mutations did not hybridize. Unlike the whole-gene probes ...

Diagnosis of enterotoxigenic Escherichia coli diarrhea was made in 109 adult males with an acute dehydrating cholera-like syndrome in Dacca, Bangladesh, by testing 10 colonies isolated from admission stool specimens for production of heat-labile and heat-stable toxins. Toxin testing of one colony yielded a diagnosis in 92% of the cases, testing of two colonies yielded a diagnosis in 95% of the ...

Escherichia vulneris is an opportunistic human pathogen. It has been primarily reported in adult patients and invasive infections have been observed in immune-suppressed individuals. This is the first report of E. vulneris causing complicated diarrhoea and sepsis in an infant. Two month old sick infant, born full-term, was admitted to the paediatrics department with loose motions and refusal to...

Molds and mycotoxins are contaminants of animal feed causing spoilage and clinical intoxication. Animal exposure to mycotoxins reflects diet composition with major differences occurring between animals kept predominantly of pastures, i.e. ruminants and horses, and those consuming formulated feed like pigs and poultry. Mixed feeds are composed of several ingredients, often sourced from different...

the aim of this study was to determine the occurrence of enterotoxigenic and enteroaggregative escherichia coli strains and antibiotic resistance of the isolates in raw milk and unpasteurized cheese. out of 200 samples of raw milk and 50 samples of unpasteurized cheeses, 96 and 24 strains of e. coli were isolated, respectively. polymerase chain reaction (pcr) was used to detect the genes encodi...

BACKGROUND The enteric nervous system is important in the pathophysiology of intestinal fluid secretion induced by cholera toxin (CT), Escherichia coli heat labile (LT), and heat stable (STa) toxins. The neurotransmitters involved are not fully elucidated. Vasoactive intestinal polypeptide (VIP), a potent intestinal secretagogue present in the enteric nervous system, is increased after exposure...