piperidines and toltrazuril

Cystoisospora suis is a common diarrheal pathogen of piglets and typically controlled by metaphylactic toltrazuril application. Recently, toltrazuril resistance has been reported in the field; however, both evaluation of toltrazuril efficacy against field isolates and the anticoccidial drug development for pigs is hampered by costs and labor of animal experimentation. Therefore an in vitro merozoite development assay was developed to evaluate the efficacy of compounds against C. suis in vitro. Monolayers of IPEC-1 cells were infected with sporozoites derived from oocysts of defined C. suis laboratory strains and the optimal infection dose as well as concentration, time point and duration of treatment were evaluated by quantitative real-time PCR. Cell cultures were treated with bumped kinase inhibitor (BKI) 1369 at different time points to evaluate the possibility to delineate effects on different developmental stages in vitro during invasion and early infection, and to determine different inhibitory concentrations (IC

Topics: Animals; Cell Line; Coccidiosis; Coccidiostats; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Drug Resistance; Inhibitory Concentration 50; Merozoites; Pilot Projects; Piperidines; Pyrimidines; Quinolines; Real-Time Polymerase Chain Reaction; Sarcocystidae; Sulfones; Sulfoxides; Swine; Swine Diseases; Triazines

We describe an outbreak of cryptosporidiosis in Stone curlews kept in a mixed-species rearing unit in Dubai. Cryptosporidium was the predominant intestinal pathogen detected, although microbiological investigations revealed a concurrent Salmonella infantis infection in two of the 29 Stone curlew chicks that died. Nineteen of 29 birds had catarrhal enteritis associated with histopathological findings of numerous Cryptosporidium developmental stages at the mucosal surface. Catarrhal enteritis was present without associated Cryptosporidium oocysts in five cases. Histology of the intestine, faecal examination by direct microscopy and antigenic detection by immunochromatography revealed the presence of Cryptosporidium spp. associated with catarrhal enteritis in intestinal sections and faeces. Clinical and histopathological outcomes of infection were severe, including disruption of intestinal epithelial integrity, the presence of numerous endogenous Cryptosporidium stages in intestinal epithelia and the excretion of large numbers of sporulated oocysts. The application of polymerase chain reaction and restriction fragment length polymorphism techniques at two 18S rRNA and one Cryptosporidium oocyst wall protein gene locus confirmed the presence of Cryptosporidium parvum DNA in faecal samples.

Topics: Animals; Antiprotozoal Agents; Bird Diseases; Birds; Cryptosporidiosis; Disease Outbreaks; Feces; Piperidines; Quinazolinones; Spiramycin; Triazines; United Arab Emirates

Ten Eimeria field isolates from North Germany were studied in battery tests for sensitivity to selected anticoccidials. A high percentage of the Eimeria field isolates (9 out of 10) showed resistance to anticoccidials, mostly multiple resistance. Partial or complete resistance to maduramicin was found in 7 field isolates, to monensin in 6, to salinomycin in 5, to nicarbazin in 8, to halofuginone in 7, to robenidine and toltrazuril in 1, and to diclazuril in 2 field isolates. Multiple resistance had developed in 7 of the 10 isolates. Cross-resistance between maduramicin, monensin, and salinomycin occurred in 5 Eimeria isolates. One isolate showed cross-resistance between diclazuril and toltrazuril. From the resistant isolates 15 pure E. acerculina and 5 pure E. brunetti strains were obtained by single oocyst infections. Seven of the E. acerculina and 4 of the E. brunetti strains showed resistance or partial resistance that was also present in the original isolate. Ten of 11 resistant strains were multiply resistant.

Topics: Animals; Chickens; Coccidiosis; Coccidiostats; Drug Resistance; Drug Resistance, Multiple; Eimeria; Germany; Lactones; Male; Monensin; Nicarbazin; Nitriles; Piperidines; Poultry Diseases; Pyrans; Quinazolines; Quinazolinones; Robenidine; Triazines