Comparing the effect of phytobiotic, coccidiostat, toltrazuril, and vaccine on the prevention and treatment of coccidiosis in broilers.

This study compared 2 herbal anticoccidiosis drugs (water-soluble and feed-additive drugs) with monensin coccidiostat, toltrazuril (TTZ, anticoccidiosis drug), and Livacox Q (anticoccidiosis vaccine) in terms of their effects on the prevention and treatment of coccidiosis in broilers. In this study, 280 Ross 308 broiler chickens (a mix of both genders) were used in a completely randomized design with 7 treatments and 5 replications each including 8 chickens per replicate. On d 21 of rearing, all experimental groups, except for the negative control group (NC), were challenged with a mixed suspension of common strains of Eimeria, and the intended indices were assessed, including performance indices, number of oocysts per gram (OPG) of feces, intestinal injuries, and the total number of intestinal bacteria. In addition, the NC and the group receiving the monensin had greater body weight gain (BWG) (P < 0.05). At the end of week 6, the monensin group had the highest feed intake (FI), while the water soluble medicine treatment resulted in the lowest feed intake (P < 0.05). Regarding the lesion scores on day 28, the highest and lowest rates of jejunal injuries were observed in the positive control group (PC), the monensin and vaccine group respectively. The rate of oocysts excretion (oocysts per gram of feces = OPG) on different days was higher in the PC group, and the use of monensin could further reduce excretion compared to the other groups (P > 0.05). Based on a comparison of the population of lactic acid bacteria between the NC and both medicinal plant treated groups, the use of these products could increase the population of these types of bacteria. Moreover, the population of Escherichia coli was less considerable in the NC and herbal powder groups (P < 0.05). Overall, similar to commercial medicines, the herbal medicines used in this project can be effective in the prevention and treatment of coccidiosis and can improve profitability in broiler rearing centers by improving intestinal health.

Process Development of Sj-p80: A Low-Cost Transmission-Blocking Veterinary Vaccine for Asiatic Schistosomiasis.

Asiatic schistosomiasis caused by Schistosoma japonicum is a neglected tropical disease resulting in significant morbidity to both humans and animals - particularly bovines - in endemic areas. Infection with this parasite leads to less healthy herds, causing problems in communities which rely on bovines for farming, milk and meat production. Additionally, excretion of parasite eggs in feces perpetuates the life cycle and can lead to human infection. We endeavored to develop a minimally purified, inexpensive, and effective vaccine based on the 80 kDa large subunit of the calcium activated neutral protease (calpain) from S. japonicum (Sj-p80). Here we describe the production of veterinary vaccine-grade Sj-p80 at four levels of purity and demonstrate in a pilot study that minimally purified antigen provides protection against infection in mice when paired with a low-cost veterinary adjuvant, Montanide™ ISA61 VG. Preliminary data demonstrate that the vaccine is immunogenic with robust antibody titers following immunization, and vaccination resulted in a reduction of parasite eggs being deposited in the liver (23.4-51.4%) and intestines (1.9-55.1%) depending on antigen purity as well as reducing the ability of these eggs to hatch into miracidia by up to 31.6%. We therefore present Sj-p80 as a candidate vaccine antigen for Asiatic schistosomiasis which is now primed for continued development and testing in bovines in endemic areas. A successful bovine vaccine could play a major role in reducing pathogen transmission to humans by interrupting the parasitic life cycle and improving quality of life for people living in endemic countries.

Effects of feeding Original XPC™ to broilers with a live coccidiosis vaccine under industrial conditions: Part 2. Cecal microbiota analysis.

Biological supplements in poultry feed are of continued interest due to the improvements in growth performance, protection from pathogen invasion, and benefits in overall host health. The fermentation metabolites of Diamond V Original XPC™ (XPC) have previously been shown to improve commercial performance and reduce Salmonella in poultry. The current study sought to characterize the cecal microbiota using culture-independent analysis based on 16S rRNA gene in Coccivac-D sprayed broilers supplemented with XPC and/or Salinomycin (SAL). Ross 708 male broilers (n = 640) were assigned to one of 4 treatments: Cocci-vaccine (T1), Cocci-vaccine + XPC (T2), Cocci-vaccine + SAL (in the grower diet only) (T3), and Cocci-vaccine + SAL (in the grower diet only) + XPC (T4). Analysis with a PCR-based denaturing gradient gel electrophoresis (DGGE) indicated a shift in the microbial populations present at the various sampling ages - 16, 28, and 42 days. Phylogenetic analysis indicated further consistency in microbial communities directly related to bird age. Identification of microbial communities present and the assessment of their respective quantities using an Illumina MiSeq indicated treatment with XPC had no significant impact on microbial diversity (Chao1 index, observed operational taxonomic unit (OTU) and phylogenetic diversity (PD) whole tree). Sampling age revealed significantly greater diversity at 16 and 28 d (P < 0.05) as compared to the 42 d for the Shannon diversity index, while showing significantly decreased richness and diversity in the 42 d sampling age (Chao1 and observed OTU; P < 0.05). The results of the current study indicate that the chicken intestinal microbiota are impacted more by temporal changes rather than by the feed additive studied.

Transcriptome profiling of gene expression during immunisation trial against Fasciola hepatica: identification of genes and pathways involved in conferring immunoprotection in a murine model.

BACKGROUND: Fasciolosis remains a significant food-borne trematode disease causing high morbidity around the world and affecting grazing animals and humans. A deeper understanding concerning the molecular mechanisms by which Fasciola hepatica infection occurs, as well as the molecular basis involved in acquiring protection is extremely important when designing and selecting new vaccine candidates. The present study provides a first report of microarray-based technology for describing changes in the splenic gene expression profile for mice immunised with a highly effective, protection-inducing, multi-epitope, subunit-based, chemically-synthesised vaccine candidate against F. hepatica. METHODS: The mice were immunised with synthetic peptides containing B- and T-cell epitopes, which are derived from F. hepatica cathepsin B and amoebapore proteins, as novel vaccine candidates against F. hepatica formulated in an adjuvant adaptation vaccination system; they were experimentally challenged with F. hepatica metacercariae. Spleen RNA from mice immunised with the highest protection-inducing synthetic peptides was isolated, amplified and labelled using Affymetrix standardised protocols. Data was then background corrected, normalised and the expression signal was calculated. The Ingenuity Pathway Analysis tool was then used for analysing differentially expressed gene identifiers for annotating bio-functions and constructing and visualising molecular interaction networks. RESULTS: Mice immunised with a combination of three peptides containing T-cell epitopes induced high protection against experimental challenge according to survival rates and hepatic damage scores. It also induced differential expression of 820 genes, 168 genes being up-regulated and 652 genes being down-regulated, p value <0.05, fold change ranging from -2.944 to 7.632. A functional study of these genes revealed changes in the pathways related to nitric oxide and reactive oxygen species production, Interleukin-12 signalling and production in macrophages and Interleukin-8 signalling with up-regulation of S100 calcium-binding protein A8, Matrix metallopeptidase 9 and CXC chemokine receptor 2 genes. CONCLUSION: The data obtained in the present study provided us with a more comprehensive overview concerning the possible molecular pathways implied in inducing protection against F. hepatica in a murine model, which could be useful for evaluating future vaccine candidates.

Investigation of the effect of coccidial vaccine challenge on apparent and standardized ileal amino acid digestibility in grower and finisher broilers and its evaluation in 21-day-old broilers.

The effect of coccidial vaccine challenge (CVC, Coccivac(®)B; challenged, CHA; or unchallenged, NCH) on ileal endogenous amino acid (IEAA) losses and standardized ileal AA digestibility (SIAAD) in 21- and 42-day-old broilers fed a corn-soybean meal-dried distillers' grains with solubles-poultry by-product meal-based diet (Expt. 1) and the effect of supplemental AA in ameliorating the effect of CVC (Expt. 2) were evaluated. Expt. 1 was designed as a 2 (d 21 or 42) x 2 (NCH or CHA) factorial arrangement of treatments with 8 replicates in a complete randomized design. The CVC birds were gavaged with 12 x coccidial vaccine on d 15 and 36 and were sampled on 6 d post challenge. SIAAD was determined by correcting apparent ileal AA digestibility for IEAA losses. Feed intake (FI) and BW gain were higher (P ≤ 0.05) in 21-day-old NCH birds compared to the 21-day-old CHA birds while 42-day-old birds had higher FI and BW gain than 21-day-old NCH and CHA birds. Ileal endogenous nitrogen loss was higher (P ≤ 0.05) in 42-day-old CHA birds compared to 42-day-old NCH birds. Apparent ileal AA digestibility in 21-day-old CHA birds was lower (P ≤ 0.05) than for 21-day-old NCH and 42-day-old NCH and CHA birds. SIAAD in 21-day-old CHA birds was lower (indispensable AA = 15.2 and dispensable AA = 17.8%-unit; P ≤ 0.05) than for 21-day-old NCH and 42-day-old NCH and CHA birds. Apparent ileal digestibility and total tract utilization of DM, N, and energy were not different between d 21 NCH and d 42 NCH and CHA birds but higher (P ≤ 0.05) than for d 21 CHA birds. Supplemental AA restored feed efficiency, but not BW gain, to that of the positive control (0.715 vs. 0.737). Results from Expt.1 showed that CVC significantly influenced ileal AA digestibility in 21- but not in 42-day-old birds. Expt. 2 showed that consideration of SIAAD in feed formulation may benefit feed efficiency.

Interleukin-10 neutralizing antibody for detection of intestinal luminal levels and as a dietary additive in Eimeria challenged broiler chicks.

Interleukin-10 (IL-10) mRNA levels are increased within intestinal mucosa after Eimeria infection. IL-10 apical receptor presence on enterocytes suggests IL-10 is secreted into the intestinal lumen. Increased IL-10 has been shown to be central to the pathogenesis of numerous intracellular pathogens; we hypothesize luminal secretion of IL-10 enables Eimeria spp. infection in chickens. This study examines intestine luminal IL-10 levels and performance in broilers challenged with Eimeria when fed an anti-IL-10 antibody. Chicks were fed a diet (1 to 21 d) with control or anti-IL-10 antibody (0.34 g egg yolk antibody powder/Kg diet) with a saline or 10× dose of Advent coccidiosis vaccine on d 3. One chick per pen was euthanized on days 2, 4, 7, 10, 13, 16, and 19 post-challenge, bled, and intestines were collected for luminal fluid IL-10 concentrations. Body weight and feed intake were measured on d 21, and oocyst shedding was assessed on d 7 post-challenge. A significant Eimeria × antibody interaction on d 21 body weight (P < 0.05) showed chicks fed control antibody, but not anti-IL-10, had significant reductions in body weight when challenged with Eimeria spp. Oocyst shedding was increased with Eimeria challenge, but dietary antibody had no effect. Plasma carotenoid levels were reduced in Eimeria challenged chicks 4, 7, 10, and 16 days post-challenge compared to unchallenged chicks. Lack of an Eimeria × antibody interaction showed anti-IL-10 was not protective against Eimeria-induced decreases in plasma carotenoids. Eimeria challenge increased intestine luminal IL-10 on days 4 and 7 post-challenge in the cecum and jejunum, respectively, compared to unchallenged. Dietary anti-IL-10 decreased luminal IL-10 in the ileum on day 2 post-challenge when compared to control antibody fed chicks. No interaction between Eimeria challenge and antibody was observed on intestine luminal contents of IL-10, suggesting anti-IL-10 was ineffective at preventing increased Eimeria-induced luminal IL-10. In conclusion, Eimeria challenge increased intestinal luminal IL-10 and anti-IL-10 was effective at preventing Eimeria-induced decreased body weight, however the mechanism anti-IL-10 antibody protects body weight during Eimeria challenge remains unknown.

Coccidiosis in poultry: anticoccidial products, vaccines and other prevention strategies.

Coccidiosis in chickens is a parasitic disease with great economic significance, which has been controlled successfully for decades using mainly anticoccidial products. However, large-scale and long-term use of anticoccidial drugs has led to the worldwide development of resistance against all these drugs. In order to minimize the occurrence of resistance, the rotation of various anticoccidial drugs in single and/or shuttle programmes is used. Unfortunately, this has not solved the anticoccidial resistance problem. Recently, live anticoccidial vaccines have been incorporated into rotation programmes, resulting in an increasing incidence of anticoccidial drug-sensitive Eimeria spp. field isolates, which may ameliorate the efficacy of anticoccidial drugs. Nevertheless, possible upcoming bans restricting the use of anticoccidials as feed additives, consumer concerns on residues and increasing regulations have prompted the quest for alternative coccidiosis control strategies. Although management and biosecurity measures could halt the introduction of Eimeria spp. to a farm, in practice they do not suffice to prevent coccidiosis outbreaks. Phytotherapy, aromatherapy and pre- and probiotics either show conflicting, non-consistent or non-convincing results, and have therefore not been applied at a large scale in the field. So far, live attenuated and non-attenuated anticoccidial vaccines have proved to be the most solid and successful coccidiosis prevention and control strategy. Despite the drawbacks associated with their production and use, their popularity is increasing. If with time, the immunogenicity of subunit vaccines can be improved, they could represent the next generation of highly efficient and low-cost anticoccidial strategies.