It was reported by Freeman (1951) and Freeman and Morse (1952) that exposure of certain nontoiigenic strains of Corynebacterium diphtheriae to specific bacteriophage resulted in the appearance of toxigenic C. diphtheriae which were resistant to the bacteriophage. It was established further by Freeman (1951) that all toxigenic cells isolated from the resistant growth were lysogenic, carrying a p...

Non-toxigenic Corynebacterium diphtheriae have become increasingly recognised as emerging pathogens across Europe causing severe invasive disease. A subset of non-toxigenic C. diphtheriae are ‘non-toxigenic tox gene-bearing’ (NTTB) strains; these strains are genotypically toxpositive, but do not express the protein. The circulation of NTTB strains was first observed during the 1990s upsurge of ...

Infection with Clostridium difficile is a growing concern because of the increasing prevalence and spread of nosocomial infections. Emergence of the hypervirulent 027/NAP1/BI strain is also notable. Existing diagnostic methods have low sensitivity or are time-consuming. Therefore, establishing a rapid and accurate microbiological diagnostic assay is needed. We evaluated the Xpert C. difficile a...

Vibrio cholerae is a natural inhabitant of the aquatic environment. However, its toxigenic strains can cause potentially life-threatening diarrhea. A quadruplex real-time PCR assay targeting four genes, the cholera toxin gene (ctxA), the hemolysin gene (hlyA), O1-specific rfb, and O139-specific rfb, was developed for detection and differentiation of O1, O139, and non-O1, non-O139 strains and fo...

Non-toxigenic V. parahaemolyticus isolates (tdh-/trh-/T3SS2-) have recently been isolated from patients with gastroenteritis. In this study we report that the larvae of the wax moth (Galleria mellonella) are susceptible to infection by toxigenic or non-toxigenic clinical isolates of V. parahaemolyticus. In comparison larvae inoculated with environmental isolates of V. parahaemolyticus did not s...

Bordetella bronchiseptica and Pasteurella multocida are etiologic agents of progressive atrophic rhinitis (PAR) and bronchopneumonia in swine. Only dermonecrotic toxin-producing strains of P. multocida play a role in atrophic rhinitis while both toxigenic and nontoxigenic strains have been associated with pneumonia. Monitoring and investigation of outbreaks involving these bacteria require sens...

Toxigenic Vibrio cholerae is the etiological agent of cholera, an acute dehydrating diarrhoea that occurs in epidemic form in many developing countries. Aquatic ecosystem is the major habitat of toxigenic V. cholerae, where it interacts with various abiotic and biotic factors to survive. To acknowledge the seasonal appearance, endemic nature and genetic deviation of V. cholerae it is essential ...

Some rare strains of Clostridium butyricum carry the gene encoding the botulinal type E neurotoxin and must be considered as possible hazards in certain types of food. The limiting growth conditions for C. butyricum were determined in peptone yeast glucose starch (PYGS) broth incubated anaerobically at 30°C for up to 42 days. The minimum pH values permitting growth depended on the acidulant and...

conclusions this study indicated the contamination of lettuce by stec strains and its possible role as the source of infection. resistance to both tetracycline and ampicillin may be considered as an emergency alarm for a multidrug resistance of stec strains. results eight samples were positive for presence of stec strains, three contained stx1, five contained stx2, and one sample was positive f...