Clostridium difficile genotypes in piglet populations in Germany.

Clostridium difficile was isolated from 147 of 201 (73%) rectal swabs of piglets from 15 farms of Lower Saxony and North Rhine-Westphalia. In 14 farms, 14 to 100% (mean, 78%) of the animals tested were culture positive. The rate of isolation was 68% postpartum, increased to 94% in animals 2 to 14 days of age, and declined to 0% for animals 49 days of age and older. There was no link between isolation and antibiotic treatment or diarrhea of piglets. Strains were assigned to 10 PCR ribotypes, and up to 4 PCR ribotypes were found to be present at the same time on a farm. The closely related PCR ribotypes 078 (55%) and 126 (20%) were most frequently recovered and were present in 13 of the 14 positive farms. The comparison of multilocus VNTR (variable number of tandem repeats) analysis (MLVA) data from this study and previously published data on human, porcine, and bovine PCR ribotype 078 isolates from 5 European countries revealed genetic differences between strains of different geographic origin and confirmed the relatedness of human and porcine C. difficile isolates. This study demonstrated that the human-pathogenic PCR ribotypes 078 and 126 are predominant in piglets in Germany. The results suggest that presence of C. difficile is correlated with animal age but not with antibiotic treatment or clinical disease. MLVA indicated that strains of the same geographical origin are often genetically related and corroborated the hypothesis of a close epidemiological connection between human and porcine C. difficile isolates.

Hydrogen peroxide-scavenging properties of normal human airway secretions.

To examine the antioxidant capacity of normal human airway secretions and to characterize its molecular components, tracheal lavages were obtained from eight patients intubated for elective surgery and free of lung disease. These samples (20 microl, approximately 6.8 microg of protein) scavenged 0.57 +/- 0.09 nmol of added 0.96 nmol hydrogen peroxide (H2O2) within 10 minutes at room temperature (n = 8). The scavenging activity was inhibited 60 +/- 4% by azide (an inhibitor of heme-containing peroxidases and catalase) and 42 +/- 9% by dapsone (an inhibitor of lactoperoxidase). Mercaptosuccinic acid (an inhibitor of glutathione peroxidase) did not significantly inhibit H2O2 scavenging by these secretions. Fourfold diluted secretions showed only nonenzymatic scavenging activity, but the addition of thiocyanate to these samples (0.4 mM; substrate for lactoperoxidase) restored their ability to scavenge H2O2. The addition of reduced glutathione (8 microM) only enhanced nonenzymatic scavenging activity. These data provide evidence that multiple enzymatic and nonenzymatic systems coexist in human airway secretions that contribute to H2O2 scavenging. It appears, however, that H2O2 is mainly consumed by the lactoperoxidase system.