Malassezia pachydermatis fungemia has been reported in patients receiving parenteral nutrition. Biofilm formation on catheters may be related to the pathogenesis of this mycosis. We investigated the biofilm-forming ability of 12 M. pachydermatis strains using a metabolic activity plate-based model and electronic microscopic evaluation of catheter surfaces. All M. pachydermatis strains developed biofilms but biofilm formation showed variability among the different strains unrelated to their clinical origin. This study demonstrates the ability of M. pachydermatis to adhere to and form biofilms on the surfaces of different materials, such as polystyrene and polyurethane.
Three groups of 10 veal calves were treated, respectively, with 5 mg of dexamethasone‐21‐isonicotinate administered intramuscularly on days 0 and 7 (group A); 0·4 mg/day of dexamethasone‐21‐phosphate administered orally for 20 days (group B); or left untreated as controls (group C). Two animals from each group were slaughtered on day 3, 7, 14, 32 and 52. The size and weight of the thymus decreased progressively in both treated groups until day 32. On day 14, in comparison with the controls, there was a mean reduction of 76 per cent in the thymus weight of group A and 35 per cent in group B. On day 32, the reductions were 13 per cent in group A and 50 per cent in group B, but the thymus weight of both groups had recovered completely by day 52. Dexamethasone‐induced changes in thymus weight associated with lymphoid depletion and fat replacement, and there were clear correlations between these changes and apoptosis of thymocytes.
6 May 2005 in Journal of Veterinary Medicine Series A
Haemoparasites in feral pigeons have been studied in several countries but no data are available from Italy. The aim of this work was to evaluate the prevalence and diversity of Haemoproteus spp./Plasmodium spp. and Leucocytozoon spp. in feral pigeons from northwest Italy, as well as the association between infection and host age or sex. Feral pigeons were collected during a regional culling programme from the Piedmont region (northwest Italy) and subjected to necropsy. Infections were detected from DNA extracted from the spleen following a nested PCR protocol. The association between sex or age and infection status was evaluated using the chi-squared test for independence or Fisher’s exact test. Out of 51 animals, 15 were positive for Haemoproteus/Plasmodium spp. and eight for Leucocytozoon spp., with a significant difference between haemoparasites prevalence. There was no significant association between age or sex and infection status. The coinfection with different haemoparasites was very significant (p < 0.01), showing a greater relative risk to be infected by a second haemoparasite in birds already infected, in particular in male and in adult pigeons. DNA sequencing of Leucocytozoon spp. showed six different lineages in pigeons, and one of Haemoproteus and Plasmodium, respectively. Blood parasites are continuously circulating around the world, and the results presented in the paper suggest that cross infection of feral pigeons with haemoparasites typical of other migratory or nonmigratory bird species is possible. Moreover, the geographical location of Italy along the main migratory routes is a crucial factor to be considered for migratory birds, because they can be affected by blood parasites detected in feral pigeons, and vice versa.