Sensitivity of Field Isolates of Eimeria to Monensin in the Turkey

The path of least resistance: paying for antibiotics in non-human uses

Antibiotic resistance is a critical threat to human and animal health. Despite the importance of antibiotics, regulators continue to allow antibiotics to be used in low-value applications--subtherapeutic dosing in animals, and spraying tobacco plants for blue mold, for example--where the benefits are unlikely to outweigh the costs in terms of increased resistance. We explore the application of a user fee in non-human uses of antibiotics. Such a fee would efficiently deter low value uses while also providing funding to support the development of the urgently needed new antibiotics.

Biological re-description of a genetically typed, single oocyst line of the turkey coccidium, Eimeria meleagrimitis Tyzzer 1929

For the purpose of re-describing the Eimeria species that infect the turkey (Meleagris gallopavo) and to establish benchmark biological information linked to genetic markers for each species, a strain of Eimeria meleagrimitis Tyzzer 1929 was obtained from a litter sample from a turkey farm in Minnesota, USA in 2008. Multiple pure lines were derived by infecting turkey poults with a single oocyst; one of these lines was then used to re-describe biological and morphological features of E. meleagrimitis in the turkey and to designate a neotype of E. meleagrimitis in the turkey. Oocyst morphometrics of this line matched those of this species as originally described by Tyzzer (Am J Hyg 10:269-383, 1929). Three asexual generations of merogony (the first generation of meronts large in size and the second and third generations small) were detected in the intestines before the onset of gametogony; no developmental stages were detected in the cecal pouches. No mortality was induced by this line of E. meleagrimitis even when turkey poults were infected with high doses of oocysts (up to 5 × 10(5) oocysts/bird) and despite the ability of E. meleagrimitis to induce severe mucosal damage in the upper and middle duodenum. Macroscopic lesions were characterized to provide a graded lesion scoring guide that should assist assessment of the severity of infections with this species in infected turkeys. The pathogenicity of the strain was investigated, and a significant reduction in weight gain and feed conversion ratio was observed with doses of 10(4) oocysts/bird or more. The maximum yield of oocysts in the feces was obtained when birds were inoculated with 5 × 10(3) oocysts.

Synthesis and Anticoccidial Activities of Eight Novel Ethyl 7-Alkyl-6-(2-Aryloxyethoxy)-4-Hydroxyquinoline-3-Carboxylates

Eight novel ethyl 7-alkyl-6-(2-aryloxyethoxy)-4-hydroxyquinoline-3-carboxylates were synthesised and their structures were identified by 1H NMR, MS, and IR spectra. The anticoccidial activities of these compounds were evaluated according to the ACI (the anticoccidial index) method. The results showed that two of these compounds exhibited anticoccidial activities against Eimeria tenella in the chicken’ diet with a dose of 27 mg kg−1.

Synthesis and Anticoccidial Activity of ethyl 6-substitutedbenzyloxy-7-alkoxy-4-hydroxyquinoline-3-carboxylates

A series of novel ethyl 6-substitutedbenzyloxy-7-alkoxy-4-hydroxyquinoline-3-carboxylates have been designed and synthesised from 4-nitro-2-alkoxyphenol. Their structures have been characterised by 1H NMR, HRMS and IR spectra. Anticoccidial activities of these compounds were evaluated according to the ACI (the anticoccidial index) method. The results indicated that three of the tested compounds exhibited anticoccidial activities against Eimeria tenella in chicken feed with a dose of 27 mg/kg.