The Shiga toxigenic Escherichia coli (STEC) O113:H21 strain 98NK2, which was responsible for an outbreak of hemolytic uremic syndrome, secretes a highly potent and lethal subtilase cytotoxin that is unrelated to any bacterial toxin described to date. It is the prototype of a new family of AB 5 toxins, comprising a single 35-kilodalton (kD) A subunit and a pentamer of 13-kD B subunits. The A sub...

Germfree mice associated with Clostridium difficile developed intestinal disease characterized by polymorphonuclear cell infiltration of the lamina propria, diarrhea, and cecal cytotoxin concentrations positive at a 10(-6) dilution. The numbers of viable bacteria never exceeded 10(10) colony-forming units per g (dry weight). Despite the high toxin levels and chronic inflammation over a 30-day p...

Earlier models of virus evolution during single infections do not include target cell limitation. Here we extend the basic mathematical framework of these theories and study the effect of target cell limitation on the evolution of antigenic variation, increasing replication rates and increasing virus load. We find that target cell limitation provides a selection pressure against antigenic diver...

OBJECTIVES We investigated the efficacy of the novel antimicrobial agent SMT19969 in treating simulated Clostridium difficile infection using an in vitro human gut model. METHODS Concentrations of the predominant cultivable members of the indigenous gut microfloras and C. difficile (total and spore counts) were determined by viable counting. Cytotoxin titres were determined using cell cytotox...

OBJECTIVES Therapeutic options in Clostridium difficile infection (CDI) are limited. We examined linezolid activity in vitro and potential therapeutic efficacy using a gut model of CDI. METHODS MICs were determined by agar incorporation for 118 diverse C. difficile faecal isolates, including epidemic strains and strains with reduced susceptibility to metronidazole. CDI was established in two ...

BACKGROUND VacA and CagA proteins have been reported to be major virulence factors of Helicobacter pylori. However, antibodies against these proteins are frequently found in the sera of Japanese patients regardless of their gastroduodenal status. AIM To evaluate the expression of VacA and CagA proteins by H pylori strains isolated in Japan. METHODS By using specific antibodies raised agains...

An outbreak of Vero cytotoxin-producing Escherichia coli O157 (VTEC O157) gastroenteritis in visitors to an open farm in North Wales resulted in 17 primary and 7 secondary cases of illness. E. coli O157 Vero cytotoxin type 2, phage type 2 was isolated from 23 human cases and environmental animal fecal samples. A case-control study of 16 primary case-patients and 36 controls (all children) showe...

Stool specimens examined for the presence of Clostridium difficile and its cytotoxin were screened by gas liquid chromatography for the presence of volatile fatty acids and p-cresol. Twenty seven of 110 (25%) stools yielded C difficile or cytotoxin; iso-valeric acid was detected in 63/110 (57%) and iso-caproic acid in 18/110 (16%) stools. Para-cresol was found in 24/71 (34%) stools examined. Is...