Contribution of usage to endoscope working channel damage and bacterial contamination.

BACKGROUND: Biofilm formation has been shown to be associated with damaged areas of endoscope channels. It was hypothesized that the passage of instruments and brushes through endoscope channels during procedures and cleaning contributes to channel damage, bacterial attachment and biofilm formation. AIM: To compare surface roughness and bacterial attachment in used and new endoscope channels in vivo and in vitro. METHODS: Surface roughness of 10 clinically used (retired) and seven new colonoscope biopsy channels was analysed by a surface profiler. For the in-vitro study, a flexible endoscope biopsy forceps was passed repeatedly through a curved 3.0-mm-diameter Teflon tube 100, 200 and 500 times. Atomic force microscopy was used to determine the degree of inner surface damage. The number of Escherichia coli or Enterococcus faecium attached to the inner surface of the new Teflon tube and the tube with 500 forceps passes in 1 h at 37oC was determined by culture. RESULTS: The average surface roughness of the used biopsy channels was found to be 1.5 times greater than that of the new biopsy channels (P=0.03). Surface roughness of Teflon tubes with 100, 200 and 500 forceps passes was 1.05-, 1.12- and 3.2-fold (P=0.025) greater than the roughness of the new Teflon tubes, respectively. The number of E. coli and E. faecium attached to Teflon tubes with 500 forceps passes was 2.9-fold (P=0.021) and 4.3-fold (P=0.004) higher compared with the number of E. coli and E. faecium attached to the new Teflon tubes, respectively. CONCLUSION: An association was found between endoscope usage with damage to the biopsy channel and increased bacterial attachment.

Maternal transference of passive humoral immunity to Haemonchus contortus in goats.

This study evaluated the transference of maternal-specific antibodies against Haemonchus contortus and the humoral immune response of 32 goat kids to natural infection by the parasite, from birth to 5 months of age. All serum samples collected immediately after birth and before colostrum ingestion were negative for H. contortus antibodies, as demonstrated by ELISA. However, 30 and 60 days after colostrum and milk ingestion, antibody detection was positive and faecal egg count (FEC) was negative, suggesting the transference of humoral immunity by colostrum. All animals were FEC-negative for Strongylodea until four months of age, consistent with the stage of animal development where nourishment comes only from breastfeeding. Animals also presented a high serum IgA concentration, associated with lower levels of total IgG. This work demonstrated that passive humoral immunity against H. contortus in goat kids occurs via the colostrum and not by transplacental transference of antibodies.