Common occurrence of zoonotic pathogen Cryptosporidium meleagridis in broiler chickens and turkeys in Algeria.

Only a small number of birds have been identified by molecular techniques as having Cryptosporidium meleagridis, the third most important species for human cryptosporidiosis. In this study, using PCR-RFLP analysis of the small subunit (SSU) rRNA gene, we examined the ileum of 90 dead chickens from 23 farms and 57 dead turkeys from 16 farms in Algeria for Cryptosporidium spp. C. meleagridis-positive specimens were subtyped by sequence analysis of the 60 kDa glycoprotein gene. Cryptosporidium infection rates were 34% and 44% in chickens and turkeys, respectively, with all positive turkeys (25) and most positive chickens (26/31) having C. meleagridis. All C. meleagridis specimens belonged to a new subtype family. The frequent occurrence of C. meleagridis in chickens and turkeys illustrates the potential for zoonotic transmission of cryptosporidiosis in Algeria.

Effects of the polyene antibiotic derivative MS-8209 on the astrocyte lysosomal system of scrapie-infected hamsters.

Amphotericine B (AmB), a macrolide polyene antibiotic, is one of a few drugs that has shown therapeutic properties in scrapie-infected hamster. Its beneficial effect on survival time is mostly marked when animals are treated with its derivative MS-8209. To explore the MS-8209 effect at the cellular level, we investigated at the light and electron microscopy levels, the sequential appearance and distribution of PrP concurrently with histopathological changes in hamsters that were infected intracerebrally with the 263 K scrapie strain and treated or not with the drug. The first histopathological modifications and PrP immunostaining were observed in the thalamus and at the inoculation site where the drug caused a delay in the appearance of lesions and PrP accumulation. Using immunoelectron microscopy, at 70 d postinfection, the inoculation site of untreated animals showed an accumulation of PrP in plaque areas constitued by filaments mixed with alterated membrane structures and in developed lysosomal system of reactive astrocytes. Most of the numerous lysosomes containing PrP showed intra-organelle filaments. In contrast, in MS-8209 treated animals, the number of lysosomes was significantly lower (p < 0.0038), with very few organelles harboring PrP. Our results suggest that in this scrapie model, MS-8209 treatment delays the disease by preventing the replication of the scrapie agent at the inoculation site where the astrocytes appear to be the first cells producing abnormal PrP. The lysosomal system of these astrocytes could constitute a privileged target for MS-8209.