Identification of Eimeria tenella sporozoite immunodominant mimotopes by random phage-display peptide libraries-a proof of concept study.

Introduction: Coccidiosis, caused by parasites of numerous Eimeria species, has long been recognized as an economically significant disease in the chicken industry worldwide. The rise of anti-coccidian resistance has driven a search for other parasite management techniques. Recombinant antigen vaccination presents a highly feasible alternative. Properly identifying antigens that might trigger a potent immune response is one of the major obstacles to creating a viable genetically modified vaccine. Methods: This study evaluated a reverse immunology approach for the identification of B-cell epitopes. Antisera from rabbits and hens inoculated with whole-sporozoites of E. tenella were used to identify Western blot antigens. The rabbit IgG fraction from the anti-sporozoite serum exhibited the highest reactogenicity; consequently, it was purified and utilized to screen two random Phage-display peptide libraries (12 mer and c7c mer). After three panning rounds, 20 clones from each library were randomly selected, their nucleotide sequences acquired, and their reactivity to anti-sporozoite E. tenella serum assessed. The selected peptide clones inferred amino acid sequences matched numerous E. tenella proteins. Results and Conclusions: The extracellular domain of the epidermal growth factor-like (EGF-like) repeats, and the thrombospondin type-I (TSP-1) repeats of E. tenella micronemal protein 4 (EtMIC4) matched with the c7c mer selected clones CNTGSPYEC (2/20) and CMSTGLSSC (1/20) respectively. The clone CSISSLTHC that matched with a conserved hypothetical protein of E. tenella was widely selected (3/20). Selected clones from the 12-mer phage display library AGHTTQFNSKTT (7/20), GPNSAFWAGSER (2/20) and HFAYWWNGVRGP (8/20) showed similarities with a cullin homolog, elongation factor-2 and beta-dynein chain a putative E. tenella protein, respectively. Four immunodominant clones were previously selected and used to immunize rabbits. By ELISA and Western blot, all rabbit anti-clone serums detected E. tenella native antigens. Discussion: Thus, selected phagotopes contained recombinant E. tenella antigen peptides. Using antibodies against E. tenella sporozoites, this study demonstrated the feasibility of screening Phage-display random peptide libraries for true immunotopes. In addition, this study looked at an approach for finding novel candidates that could be used as an E. tenella recombinant epitope-based vaccine.

Histological Identification and Quantification of Eosinophils and Ascites in Leghorn Chickens Treated with High Oral Concentrations of NaCl-Pilot Study.

The purpose of this pilot study was to determine the role played by eosinophils in NaCl poisoning and right cardiac hypertrophy (ascitic syndrome) in Leghorn chickens, as well as the histological findings in the central nervous system (CNS), liver, and kidney. Moreover, the hypertrophy of the right ventricle index (HRVI) as an indicator of ascites was evaluated. Male SPF Leghorn birds at 28 days of age were submitted to two experiments. Food and water (FW) experiment: birds were treated with food plus 3.3% NaCl for the next 27 days and 1% NaCl in their drinking water from days 22 to 27. Water experiment (W): birds were treated with 1% NaCl in their drinking water for 5 days. In both experiments, the chickens exhibited loss of appetite, diuresis, and watery, green diarrhea during treatment days; at 24−27 td-FW and experiment W, the birds showed nervous signology (prostration, running movements, tremors, and comatose state). In the leukogram at 28 td-FW, an increase (p < 0.05) in heterophiles and basophils was observed. CNS eosinophilia was not observed in birds intoxicated with NaCl, though they did present demyelination in the brain and spinal cord, hepatic degeneration, mesangial proliferative glomerulopathy, and acute proximal renotubular necrosis.

Nitrogen fixation in a landrace of maize is supported by a mucilage-associated diazotrophic microbiota.

Plants are associated with a complex microbiota that contributes to nutrient acquisition, plant growth, and plant defense. Nitrogen-fixing microbial associations are efficient and well characterized in legumes but are limited in cereals, including maize. We studied an indigenous landrace of maize grown in nitrogen-depleted soils in the Sierra Mixe region of Oaxaca, Mexico. This landrace is characterized by the extensive development of aerial roots that secrete a carbohydrate-rich mucilage. Analysis of the mucilage microbiota indicated that it was enriched in taxa for which many known species are diazotrophic, was enriched for homologs of genes encoding nitrogenase subunits, and harbored active nitrogenase activity as assessed by acetylene reduction and 15N2 incorporation assays. Field experiments in Sierra Mixe using 15N natural abundance or 15N-enrichment assessments over 5 years indicated that atmospheric nitrogen fixation contributed 29%-82% of the nitrogen nutrition of Sierra Mixe maize.