J Glenn Songer

..difficile alone, while an additional quarter of affected piglets may have had mixed infections. C. difficile may be the most important uncontrolled cause of neonatal diarrhea in pigs...

..difficile strains (either ribotype 078/toxinotype V [73%] or 027/toxinotype III [NAP1 or NAP1-related; 27%]). These findings indicate that food products may play a role in interspecies C. difficile transmission...

..difficile-associated disease of greater than historical severity. The diagnosis was peracute typhlocolitis, with lesions and history typical of those attributed to colitis X...

..8% of litters and 3.4% of piglets given spores orally. These data support a contention that precolonization by a nontoxigenic strain can ameliorate the pre-weaning growth retardation associated with C. difficile infection in piglets...

..difficile that in many cases are identical to those from food animals and diseased humans. Transmission, food animals to foods to humans, has not been documented...

..However, it may be important to consider the use of an additional method for the detection of beta2 toxin in non-porcine cpb2-positive isolates when making claims about the role of beta2 in enteritis in non-porcine species...

..St. Louis, MO, U.S.A.] and add strength to a working hypothesis that C. difficile infection and the accompanying intoxication can manifest as diarrhea in calves. It seems clear that calves serve as multiplying hosts for this organism...

..The repA gene from pAP2 was nonfunctional in Escherichia coli and at least one A. pyogenes isolate, suggesting that there may be host-encoded factors required for replication of this plasmid...

..NE strains must have specific poultry-associated virulence attributes, such as the recently identified NetB and other factors, which allow for the development of disease...

..However, in three strains, this insertion resulted in a partial duplication of orfY...

..Porcine isolates comprised four PCR ribotypes, but one, ribotype 078, predominated (83%). This was also the most common ribotype (94%) among 33 calf isolates but was rarely identified in other species...

..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...

..After challenge, vaccinated birds had average IgG (IgY) titers>15-fold higher than those in non-vaccinated birds. These results suggest that alpha toxin may serve as an effective immunogen, and, as such, may play a role in pathogenesis...

..6% of porcine isolates not present in clonal complex 3 (n=28). The data obtained indicates that MLST may be used to identify host species relationships with respect to these C. perfringens isolates...

..Its negative predictive value was 87, but its positive predictive value was 100. Thus, the Tox A/B II kit is apparently superior to the Gastro-tect Toxin A+B test for diagnosis of CDAD in neonatal pigs...

..While these mutations conferred resistance to erythromycin, oleandomycin, and spiramycin, they did not confer resistance to tylosin...

..Regardless, the presence of the plo gene as part of a genomic islet inserted between genes essential for normal growth may provide selective pressure for the retention of this important virulence factor...

..Furthermore, in a mouse model of infection, A. pyogenes carrying the F(497) mutation was as attenuated as a PLO-deficient strain, indicating that the cytolytic activity of PLO is important in virulence...

..The mobile nature of this determinant and the presence of A. pyogenes in the gastrointestinal tract of cattle and pigs suggest that A. pyogenes may have inherited this determinant within the gastrointestinal tracts of these animals...

..However, the identification of apparently nonexpressed, atypical cpb2 genes raises the question of whether this protein plays the same role in enteritis in other animal species...

..9- and 5.7-fold, respectively. These data indicate that CbpA, a collagen-binding protein of A. pyogenes, plays a role in the adhesion of this organism to host cells...

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..In addition, in vivo passage apparently increases strain virulence. Virulence varies from strain-to-strain; NetB-producing strains were virulent, as were some NetB non-producing strains...

..Finally, C. perfringens proved to have a dynamic population and availability of more genome sequences and use of comparative proteomics and animal modeling would provide more insight into the virulence of this organism...

..Future progress may be based in large part on genomic and proteomic analyses...

..Clostridium difficile can also be a normal inhabitant of the intestine of healthy pigs, and diagnosis of enteric infection with this microorganism is based on detection of its toxins in feces or intestinal contents...

..Given the widespread occurrence of the disease, there is substantial effort to develop immunoprophylactic products...

..The wild-type adhesion phenotype was restored by providing nanP in trans. These data indicate that the neuraminidases of A. pyogenes play a role in adhesion of this organism to host epithelial cells...

..pseudotuberculosis fagB(C) mutant in vitro, this mutant showed reduced virulence compared to wild-type in a goat model of caseous lymphadenitis. Thus, expression of the fag genes in the host appears to contribute to virulence...

..6% of porcine isolates were resistant to the tetracyclines, compared with 25.9% of bovine isolates. These data suggest that a large proportion of A. pyogenes field isolates may be resistant to these commonly used antimicrobial agents...

..Alternative tests such as immunohistochemical assay were diagnostically useful. Additional research might uncover virulence factors, host factors, and the burden of disease in the population...

..nodosus to cause ovine footrot is regulated, as we have shown that the biogenesis of type IV fimbriae in D. nodosus is regulated by a sigma 54-dependent PilR/S system that also indirectly controls protease secretion...

..The EIA test is considered suitable as an aid for the diagnosis of C. difficile enteritis because of the high correlation between EIA results and those of the tissue culture cytotoxicity assay...

..intermedia and C. pseudotuberculosis PLD is a result of exposure of phosphatidylserine, and the higher potency of P1 toxin can be explained by its additional effect of cleavage of glycophorins...

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..Collectively, our present results support a significant association between CPB2-positive C. perfringens isolates and diarrhea in piglets...

..Enterotoxigenic Clostridium perfringens type A is the third leading cause of foodborne disease in the United States, resulting annually in an estimated 250,000 cases of a typically mild, self-limiting gastrointestinal illness...

..However, although such tests have a presumptive diagnostic value when positive, they cannot be used to rule out a diagnosis of enterotoxemia when negative...

..Screening of these proteins against ovine antisera identified eight immunogenic proteins that are candidate antigens for a cross-protective vaccine...

..Since ceramide phosphate does not appear to have such effects, we suggest that SMase D is a useful probe of membrane SM...

..This information can be used to model the mode of action of ETX, and to define regions of the molecule that could be targeted for immunoprophylaxis and treatment. ..