salinomycin and diclazuril

Anticoccidial vaccine and an anticoccidial drug rotation program were compared to determine which program was more effective in producing coccidia populations sensitive of 1 ppm diclazuril. The study used an anticoccidial drug-sensitivity battery test (AST) to determine the baseline level of diclazuril sensitivity to field isolates of Eimeria spp. from seven broiler complexes that had used diclazuril. Based on percentage reduction in weight gain and lesion scores, 25% or fewer of the isolates were effectively controlled by diclazuril. Following the baseline sampling, four of the complexes switched to a nondiclazuril in-feed anticoccidial drug program and three of the complexes switched to a vaccination program for two broiler grow-out cycles as the sole coccidiosis-control program. This study demonstrated that the vaccine used (Coccivac-B) contained anticoccidial drug-sensitive strains. Eimeria isolates were subsequently collected from the identical houses and diclazuril AST results were compared with the baseline AST results. Following the two grow-out cycles, sensitivity of the isolates to diclazuril from the four complexes that continued to use in-feed anticoccidial drugs remained essentially unchanged. The isolates from the three complexes that switched to the vaccination program demonstrated a marked increase in diclazuril sensitivity, with 60%-100% of the isolates from each complex effectively controlled by diclazuril. Vaccination with the anticoccidial drug-sensitive strains produced a measurable increase in the level of sensitivity to diclazuril.

Topics: Animals; Chickens; Coccidiosis; Coccidiostats; Drug Resistance; Eimeria; Male; Monensin; Nicarbazin; Nitriles; Poultry Diseases; Protozoan Vaccines; Pyrans; Triazines

A 49-d floor pen study was conducted with broiler chickens to compare the effects of different anticoccidial withdrawal times on the efficacy of 1 ppm diclazuril. The starter diet in three treatments contained 66 ppm salinomycin + 50 ppm roxarsone (3-nitro-4-hydroxyphenylarsonic acid), followed by 1 ppm diclazuril in the grower diet commencing on Day 17. Diclazuril was withdrawn from these treatments on Day 28, 35, or 42 (finisher diet), respectively. Two other treatments in the study were given 66 ppm salinomycin + 50 ppm roxarsone in the starter and grower diets to Day 28 or no anticoccidial (unmedicated). The starter (Days 0 to 16), grower (Days 17 to 35), and finisher (Days 36 to 49) diets in each treatment included 55 ppm bacitracin methylene disalicylate for growth promotion. Fifty 1-d-old chicks were randomly allotted to each of 10 pens per treatment using a randomized complete block design. Birds in each pen were raised on litter naturally contaminated with a mixture of Eimeria acervulina, Eimeria maxima, and Eimeria tenella. The results demonstrated that some performance loss occurred in the salinomycin Day 28 treatment. Means for weight gain and feed conversion on Day 49 were improved (P < 0.05) in each diclazuril treatment in comparison with the salinomycin and unmedicated treatments. Feed conversion means in the diclazuril Day 35 and Day 42 treatments were improved (P < 0.05) in comparison with the diclazuril Day 28 treatment, indicating that shorter withdrawal times provided further benefit.

Topics: Aging; Animal Nutritional Physiological Phenomena; Animals; Chickens; Coccidiosis; Coccidiostats; Diet; Eimeria; Housing, Animal; Nitriles; Parasite Egg Count; Poultry Diseases; Pyrans; Triazines; Weight Gain

Chicken coccidiosis, caused by an obligate intracellular protozoan parasite of the genus Eimeria, is a major parasitic disease in the intensively reared poultry industry. Due to the widespread use of anticoccidial drugs, resistance has become an inevitable problem. In our previous study, Eimeria tenella citrate synthase (EtCS) was found to be up-expressed in two drug-resistant strains (diclazuril-resistant and maduramycin-resistant strains) compared to drug-sensitive strain by RNA sequence. In this study, we cloned and expressed EtCS and obtain its polyclonal antibodies. Quantitative real-time polymerase chain (qPCR) reactions and Western blots were used to analyze the transcription and translation levels of EtCS in sensitive and three drug-resistant strains. Compared with the sensitive strain, the transcription of EtCS was both significantly upregulated in diclazuril-resistant and maduramycin-resistant strains, but was not significantly different in salinomycin-resistant strain. No significant difference was seen in translation level in the three drug-resistant strains. Indirect immunofluorescence indicated that EtCS was mainly located in the cytoplasm of sporozoites except for posterior refractile bodies and in the cytoplasm and surface of merozoites. Anti-rEtCS antibody has inhibitory effects on E. tenella sporozoite invasion of DF-1 cells and the inhibition rate is more than 83%. Binding of the protein to chicken macrophage (HD11) cells was confirmed by immunofluorescence assays. When macrophages were treated with rEtCS, secretion of nitric oxide and cell proliferation of the macrophages were substantially reduced. These results showed that EtCS may be related to host cell invasion of E. tenella and involve in the development of E.tenella resistance to some drugs.

Topics: Amino Acid Sequence; Animals; Antibodies, Protozoan; Base Sequence; Blotting, Western; Chickens; Citrate (si)-Synthase; Cloning, Molecular; Coccidiosis; Eimeria tenella; Fluorescent Antibody Technique, Indirect; Immune Sera; Macrophages; Merozoites; Mice; Nitric Oxide; Nitriles; Poultry Diseases; Pyrans; Rabbits; Real-Time Polymerase Chain Reaction; Specific Pathogen-Free Organisms; Sporozoites; Triazines

The presence of mycotoxins in broiler feed can have deleterious effects on the wellbeing of the animals and their performance. Mycotoxin binders are feed additives that aim to adsorb mycotoxins in the intestinal tract and thereby prevent the oral absorption of the mycotoxin. The simultaneous administration of coccidiostats and/or antimicrobials with mycotoxin binders might lead to a reduced oral bioavailability of these veterinary medicinal products. This paper describes the influence of 3 mycotoxin binders (i.e., clay 1 containing montmorillonite, mica, and feldspars; clay 2 containing montmorillonite and quartz; and yeast 1 being a modified glucomannan fraction of inactivated yeast cells) and activated carbon on the oral bioavailability and pharmacokinetic parameters of the antimicrobials doxycycline and tylosin, and the coccidiostats diclazuril and salinomycin. A feeding study with 40 15 day-old broilers was performed evaluating the effects of long-term feeding 2 g mycotoxin binder/kg of feed. The birds were randomly divided into 5 groups of 8 birds each, i.e., a control group receiving no binder and 4 test groups receiving either clay 1, clay 2, yeast 1, or activated carbon mixed in the feed. After 15 d of feeding, both the control and each test group were administered doxycycline, tylosin, diclazuril, and salinomycin, consecutively, respecting a wash-out period of 2 to 3 d between each administration. The 4 medicinal products were dosed using a single bolus administration directly in the crop. After each bolus administration, blood was collected for plasma analysis and calculation of the main pharmacokinetic parameters and relative oral bioavailability (F = area under the plasma concentration-time curve (AUC0-8 h) in the test groups/AUC0-8 h in the control group)*100). No effects were observed of any of the mycotoxin binders on the relative oral bioavailability of the coccidiostats (i.e., F between 82 and 101% and 79 and 93% for diclazuril and salinomycin, respectively). Also, no significant effects could be noticed of any of the mycotoxin binders on the relative oral bioavailability of the antimicrobials doxycycline and tylosin (i.e., F between 67 and 83% and between 43 and 104%, respectively).

Topics: Administration, Oral; Animals; Anti-Bacterial Agents; Biological Availability; Chickens; Coccidiostats; Doxycycline; Mycotoxins; Nitriles; Pyrans; Random Allocation; Triazines; Tylosin

This study investigated the effects of various coccidiosis control programs in combination with antibiotic growth promoters (AGPs) on growth performance and host immune responses in broiler chickens. The coccidiosis programs that were investigated included in ovo coccidiosis vaccination (CVAC) with Inovocox or in-feed medication with diclazuril as Clinacox (CLIN) or salinomycin (SAL). The AGPs were virginiamycin or bacitracin methylene disalicylate plus roxarsone. As a negative control, chickens were non-vaccinated and fed with non-supplemented diets (NONE). All animals were exposed to used litter from a commercial broiler farm with confirmed contamination by Eimeria parasites to simulate in-field exposure to avian coccidiosis. Broiler body weights in the CVAC group were greater at 14 and 32 days of age, but not at day 42, compared with the NONE, CLIN, and SAL groups. At day 14, the SAL group showed decreased body weight and reduced ConA-stimulated spleen cell proliferation compared with the CLIN and SAL groups. In contrast, at days 34 and 43, splenocyte proliferation was greater in the CVAC and CLIN groups compared with the NONE and SAL groups. Lymphocyte subpopulations and cytokine mRNA expression levels in the intestine and spleen were also altered by the denoted treatments. Collectively, these results suggest that in ovo coccidiosis vaccination or coccidiostat drug medication programs in combination with AGPs influences chicken growth and immune status in an Eimeria-contaminated environment.

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Chick Embryo; Chickens; Coccidiosis; Coccidiostats; Cytokines; Eimeria; Gene Expression Regulation; Male; Nitriles; Poultry Diseases; Protozoan Vaccines; Pyrans; RNA, Messenger; Spleen; Triazines

Seven anticoccidial drugs commonly used in poultry (diclazuri), monensin, salinomycin, halofuginone, nicarbazin, robenidine, amprolium, and lasalocid) were tested for residual activity after withdrawal. In each test, the products were given at the recommended level to cages of 10 broiler chickens. Oral inoculation with coccidia was given after withdrawal of medication. Birds pretreated with 1 ppm of diclazuril and inoculated with Eimeria tenella after drug withdrawal had normal weight gain and very low lesion scores. Residual activity depleted gradually over several days, as shown by higher lesion scores when medication was withdrawn for up to 3 days before inoculation. Similar results were observed when young birds were inoculated with a mixture of E. tenella, E. maxima and E. acervulina, and also when birds were given diclazuril to market weight (6 weeks of age) and inoculated with a mixture of six species of Eiméria (The above species plus E. brunetti, E. mitis, and E. necatrix) after withdrawal of medication for 2 days. In contrast, there was no evidence of residual anticoccidial activity with nicarbazin, halofuginone, lasalocid, amprolium, salinomycin or monensin. Overall, the residual activity was unique to diclazuril.

Topics: Amprolium; Animal Feed; Animals; Chickens; Coccidiosis; Coccidiostats; Eimeria tenella; Feces; Female; Lasalocid; Male; Monensin; Nicarbazin; Nitriles; Piperidines; Poultry Diseases; Pyrans; Quinazolines; Quinazolinones; Random Allocation; Triazines

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