The level of environmental oxygen (EO) within various Pseudomonas aeruginosa infection sites is low (microaerobic), and this can affect the production of different virulence factors. Expression of the toxA gene, encoding exotoxin A (ETA), is regulated by regA, ptxR and pvdS. Moreover, the iron-starvation sigma factor PvdS directs the transcription of pyoverdine siderophore genes (e.g. pvdD). DN...

Pyrenophora tritici-repentis (Ptr), a necrotrophic fungus and the causal agent of tan spot of wheat, produces one or a combination of host-selective toxins (HSTs) necessary for disease development. The two most studied toxins produced by Ptr, Ptr ToxA (ToxA) and Ptr ToxB (ToxB), are proteins that cause necrotic or chlorotic symptoms respectively. Investigation of host responses induced by HSTs ...

Tan spot and Septoria nodorum blotch (SNB) are important diseases of wheat caused by the necrotrophic fungi Pyrenophora tritici-repentis and Parastagonospora nodorum, respectively. The P. tritici-repentis necrotrophic effector (NE) Ptr ToxB causes tan spot when recognized by the Tsc2 gene. The NE ToxA is produced by both pathogens and has been associated with the development of both tan spot an...

The wheat tan spot fungus (Pyrenophora tritici-repentis) produces a well-characterized host-selective toxin (HST) known as Ptr ToxA, which induces necrosis in genotypes that harbor the Tsn1 gene on chromosome 5B. In previous work, we showed that the Stagonospora nodorum isolate Sn2000 produces at least 2 HSTs (SnTox1 and SnToxA). Sensitivity to SnTox1 is governed by the Snn1 gene on chromosome ...

BACKGROUND Progressive atrophic rhinitis (PAR) in pigs is caused by toxigenic Pasteurella multocida. In Switzerland, PAR is monitored by selective culture of nasal swabs and subsequent polymerase chain reaction (PCR) screening of bacterial colonies for the P. multocida toxA gene. A panel of 203 nasal swabs from a recent PAR outbreak were used to evaluate a novel quantitative real-time PCR for t...

Toxin production and the presence of the toxA gene was assayed in 24 Pasteurella multocida strains isolated from pigs with pneumonia and pleuritis in the State of Rio Grande do Sul, Brazil. Toxigenicity was assessed through a mouse lethality test and a PCR amplification assay was used to obtain a 300 bp product from the toxA gene. In order to demonstrate that the amplified product corresponded ...

The role of Pseudomonas aeruginosa exotoxin A (ETA) as a virulence factor in the lung infections of cystic fibrosis (CF) patients is not well understood. Transcript-accumulation studies of bacterial populations in sputum reveal high levels of transcription of toxA, which encodes ETA, in some patients with CF. However, in general, tissue damage in the lungs of patients with CF does not seem to b...

Clostridium difficile and Clostridium perfringens type A are infectious agents of enteric diseases. The main virulence factors of these microorganisms include toxins A and B of C. difficile (ToxA and ToxB) and enterotoxin of C. perfringens (Cpe). In this study genetic constructions have been created for the expression of ToxA, ToxB and Cpe fragments either as individual components or as a hybri...

The ToxA gene of Pyrenophora tritici-repentis encodes a host-selective toxin (Ptr ToxA) that has been shown to confer pathogenicity when used to transform a non-pathogenic wheat isolate. Major karyotype polymorphisms between pathogenic and non-pathogenic strains, and to a lesser extent among pathogenic strains, and among non-pathogenic strains were identified. ToxA was localized to a 3.0 Mb chr...

INTRODUCTION Pseudomonas aeruginosa is a gram-negative and opportunistic bacterium that causes opportunistic infections in immunosuppressed patients. The main purpose of this study was to investigate the association between exotoxin A and exoenzyme S production with antibiotic resistance patterns. METHODS The toxA and exoS genes were detected in 102 clinical isolates by PCR. Antibiotic suscep...