Pigbel remains a likely significant cause of morbidity and mortality in the highlands of Papua New Guinea (PNG), two decades after the administration of pigbel vaccination ceased. There is a need for an effective surveillance program for pigbel to better understand the disease burden and to target communities for preventive strategies. This paper reviews the epidemiology, pathogenesis, recent history and current data on the burden of pigbel in PNG. We propose a surveillance program based on clinical recognition of likely cases and laboratory confirmation using an ELISA assay for Clostridium perfringens type C beta-toxin. Research aimed at validating this approach in the clinical setting is outlined.
Clostridium Infections/epidemiology/*microbiology/*prevention & control ; Clostridium perfringens/pathogenicity ; Enteritis/epidemiology/*microbiology/*prevention & control ; Health Services Needs and Demand ; Humans ; Incidence ; Papua New Guinea/epidemiology ; Population Surveillance

Clostridium (C.) difficile is a common cause of nosocomial diarrhea in horses. Vancomycin and metronidazole have been used as standard treatments but are only moderately effective, which highlights the need for a novel alternative therapy. In the current study, we prepared antiserum of equine origin against both C. difficile toxins A and B as well as whole-cell bacteria. The toxin-neutralizing activities of the antibodies were evaluated in vitro and the prophylactic effects of in vivo passive immunotherapy were demonstrated using a conventional mouse model. The data demonstrated that immunized horses generated antibodies against both toxins A and B that possessed toxin-neutralizing activity. Additionally, mice treated with the antiserum lost less weight without any sign of illness and regained weight back to a normal range more rapidly compared to the control group when challenged orally with 10(7) C. difficile spores 1 day after serum injection. These results indicate that intravenous delivery of hyperimmune serum can protect animals from C. difficile challenge in a dose-dependent manner. Hence, immunotherapy may be a promising prophylactic strategy for preventing C. difficile infection in horses.
Animals ; Antibodies, Bacterial/blood/*immunology/therapeutic use ; Bacterial Proteins/immunology/therapeutic use ; Bacterial Toxins/immunology/therapeutic use ; Clostridium Infections/microbiology/prevention & control/*veterinary ; Clostridium difficile/*immunology ; Enterotoxins/immunology/therapeutic use ; Female ; Horse Diseases/microbiology/*prevention & control ; Horses ; Immune Sera/*immunology ; Immunization, Passive/*veterinary ; Mice ; Mice, Inbred C57BL ; Spores, Bacterial/immunology

In order to amplify alpha toxin gene of Clostridium septicum HeB01 strain, one pair of primers was designed according to the GenBank sequence, and a 1323bp alpha toxin gene fragment was obstained by PCR. Sequence analysis indicated that the homology of the nucleotid sequence of HeB01 strain to those other reference strains was more than 99.5% . The expression plasmid pQE30-alpha was constructed by inserting alpha toxin gene into the prokaryotic expression vector pQE30. The plasmid expressed when the recombinant strain M15(pQE30-alpha) was induced by IPTG. The specific 48 kD protein was detected SDS-PAGE and the immunogenicity of the expressed alpha toxin was confirmed by Western blot and ELISA. The expressed alpha toxin was transformed into alpha toxoid vaccine by adding 0.3% formaldehyde into alpha toxin. The protective immune response was proved after the mice was immunized with alpha toxoid vaccine. The results showed that the recombinanted strain M15 (pQE30-alpha) could be as a candidate of alpha toxoid vaccine to provide protective immune response against clostridium septicum infection.
Animals ; Antibodies, Bacterial ; blood ; immunology ; Bacterial Toxins ; genetics ; immunology ; metabolism ; Blotting, Western ; Cloning, Molecular ; Clostridium Infections ; immunology ; microbiology ; prevention & control ; Clostridium septicum ; genetics ; immunology ; metabolism ; Electrophoresis, Polyacrylamide Gel ; Enzyme-Linked Immunosorbent Assay ; Escherichia coli ; genetics ; Gene Expression Regulation, Bacterial ; Mice ; Polymerase Chain Reaction ; Recombinant Proteins ; administration & dosage ; immunology ; metabolism ; Toxoids ; immunology ; Vaccination