Disease relevance of cpb2

• Using polymerase chain reaction (PCR), the current study determined that the cpb2 gene encoding the recently discovered beta2 toxin is present in <15% of food poisoning isolates, which typically carry a chromosomal cpe gene [1].
• The finding that CpCna binds collagen and that the cna gene is associated with the consensus cpb2 allele implicates CpCna as a potential virulence factor in porcine enteritis caused by C. perfringens [2].
• Molecular characterization of Clostridium perfringens isolates from humans with sporadic diarrhea: evidence for transcriptional regulation of the beta2-toxin-encoding gene [3].
• In addition, Beta2 toxin-producing C. perfringens strains were found to be associated with animal diseases such as necrotic enteritis in piglets and enterocolitis in horses [4].
• Enterotoxemia associated with beta2 toxin-producing Clostridium perfringens type A in two Asiatic black bears (Selenarctos thibetanus) [5].

High impact information on cpb2

• However, >75% of AAD/SD isolates, which usually carry a plasmid cpe gene, tested cpb2(+) by PCR [1].
• The 34.5-kb pCPF4969 variable region contains ORFs that putatively encode two bacteriocins and a two-component regulator similar to VirR/VirS, while the approximately 43.6-kb pCPF5603 variable region contains a functional cpb2 gene and several metabolic genes [6].
• Regulated expression of the beta2-toxin gene (cpb2) in Clostridium perfringens type a isolates from horses with gastrointestinal diseases [7].
• Recent epidemiological studies suggested that C. perfringens isolates carrying the gene encoding CPB2 (cpb2) are strongly associated with clostridial GI diseases in domestic animals, including necrotic enteritis in piglets and typhlocolitis in horses [8].
• PCR and restriction fragment length polymorphism analysis reconfirmed the presence of cpb2 gene sequences in all the disease isolates included in the study [8].

Chemical compound and disease context of cpb2

• Some isolates carried the gene for beta2 toxin, suggesting a role for beta2 toxin in caprine enterotoxemia, a common cause of death in growing kids [9].

Biological context of cpb2

• Beta2 toxin, encoded by one of two cpb2 alleles, is implicated as a virulence factor in this disease [2].
• In C. perfringens strain 13, the consensus cpb2 allele is found on the plasmid pCP13, which also carries cna, encoding a putative collagen binding protein, CpCna [2].
• Most of the isolates were found to be genotype A and the gene encoding beta2-toxin [corrected] was present in 50% of the isolates genotyped [10].
• This study compared genotype and phenotype of the beta2 toxin between C. perfringens isolates from a group of healthy calves (n=14, 87 isolates) and from a group of enterotoxaemic calves (n=8, 41 isolates) [11].
• Seven hundred and fourteen non-enterotoxigenic type A C. perfringens isolated from 133 calves with lesions of enterotoxaemia and high clostridial cell counts (study population) and 386 isolated from a control population of 87 calves were tested by a colony hybridisation assay for the beta2 toxin [12].

Anatomical context of cpb2

• These data are supportive for the suggestion of a causal relationship of beta2 toxin-producing strains with digestive tract diseases in piglets [13].
• This is the first report of enterotoxemia associated with the presence of C. perfringens producing beta2-toxin in the tissues and intestinal content of Asiatic black bears [5].
• The expression of the beta2-toxin gene in vivo was demonstrated by the immunohistochemical localisation of the beta2-toxin to the microscopical lesions in the small intestine [14].
• Twelve adult nonlactating dairy cows were inoculated with 10 mL of pure culture broth of C. perfringens type A (beta2 toxin positive) into the abomasum (n = 6) or jejunum (n = 6) [15].

Analytical, diagnostic and therapeutic context of cpb2

• Finally, CPB2-specific Western blotting demonstrated CPB2 expression by all of the cpb2-positive isolates surveyed [8].
• Furthermore, genotyping by pulsed-field gel electrophoresis analyses showed that the pig GI disease isolates included in this study all carry a plasmid cpb2 gene, yet no clonal relationships were detected between the cpb2-positive pig GI disease isolates surveyed [8].
• Recent epidemiological studies suggested that cpb2-positive Clostridium perfringens isolates are associated with gastrointestinal (GI) diseases in horses [7].
• However, Southern blot and nucleotide sequencing analyses identified intact cpb2 open reading frames in all of our surveyed horse GI disease isolates [7].
• Furthermore, reverse transcriptase PCR and Northern blot analyses showed that cpb2 genes in all of our surveyed horse GI disease isolates were transcriptionally active, i.e., an approximately 1.2-kb cpb2-specific mRNA was identified in total RNA from our surveyed isolates [7].

References