Characterization of Eimeria Species in Commercial Broilers by PCR Based on ITS1 Regions of rDNA

Background: Coccidiosis is an intestinal disease of chickens caused by various species of proto­zoan parasites within the genus Eimeria. Diagnosis and genetic characterization of different spe­cies of Eimeria are central to the prevention, surveillance, and control of coccidiosis. The aim of this study was to detect different chicken Eimeria species from several areas in Khuzestan, south­west Iran.Methods: From February to September 2008, PCR assay as well as parasitological examinations was applied for the identification of field isolates of Eimeria parasites around Ahvaz, center of Khuzestan, southwest Iran. Data were analyzed by the Kappa statistic test.Results: Eimeria maxima, E. necatrix, E. tenella, E. acervulina and E. mitis were detected in this study. The prevalence of Eimeria spp. was 31.5% (126 of 400) and E. tenella was the most preva­lent species in Khuzestan. Based on the Kappa statistical test, a good correlation between the results of PCR and traditional biometrical methods was only observed for E. maxima.Conclusion: The present study is the first on the prevalence of Eimeria species in Khuzestan, based on the molecular findings. We believe that traditional methods are not sufficiently reliable for specific diagnosis of Eimeria species in chickens and PCR based amplification of DNA se­quence of parasite, could resolve this problem

Molecular cloning of S1 glycoprotein gene of infectious bronchitis virus (IBV) serotype 793/B in secretory Pichia pastoris vector

In vitro protein expression is an important method of obtaining large amounts of viral proteins to investigate their biological properties. The S1 glycoprotein of infectious bronchitis virus, due to its effective immune-dominant role is an appropriate candidate for production of recombinant vaccine against infectious bronchitis disease. In this study, the S1 gene fragment of infectious bronchitis virus strain793/B was amplified using reverse transcriptase-polymerase chain reaction (RT-PCR) and purified. Itwas then cloned into pPICZαA a secretory expression vector of Pichia pastoris. The insertion was proved by PCR analysis and isolation of gene from construct by restriction enzymes and finally, it was sequenced. After the expression of S1 gene in P. pastoris expression system, it was found that it could be used in the production of recombinant vaccines against infectious bronchitis disease. Keywords: Infectious bronchitis, S1 glycoprotein, cloning, Pichia pastori

Sequence Analysis of the Genome of Piscine Orthoreovirus (PRV) Associated with Heart and Skeletal Muscle Inflammation (HSMI) in Atlantic Salmon (Salmo salar)

Piscine orthoreovirus (PRV) is associated with heart- and skeletal muscle inflammation (HSMI) of farmed Atlantic salmon (Salmo salar). We have performed detailed sequence analysis of the PRV genome with focus on putative encoded proteins, compared with prototype strains from mammalian (MRV T3D)- and avian orthoreoviruses (ARV-138), and aquareovirus (GCRV-873). Amino acid identities were low for most gene segments but detailed sequence analysis showed that many protein motifs or key amino acid residues known to be central to protein function are conserved for most PRV proteins. For M-class proteins this included a proline residue in m2 which, for MRV, has been shown to play a key role in both the formation and structural organization of virus inclusion bodies, and affect interferon-b signaling and induction of myocarditis. Predicted structural similarities in the inner core-forming proteins l1 and s2 suggest a conserved core structure. In contrast, low amino acid identities in the predicted PRV surface proteins m1, s1 and s3 suggested differences regarding cellular interactions between the reovirus genera. However, for s1, amino acid residues central for MRV binding to sialic acids, and cleavage- and myristoylation sites in m1 required for endosomal membrane penetration during infection are partially or wholly conserved in the homologous PRV proteins. In PRV s3 the only conserved element found was a zinc finger motif. We provide evidence that the S1 segment encoding s3 also encodes a 124 aa (p13) protein, which appears to be localized to intracellular Golgi-like structures. The S2 and L2 gene segments are also potentially polycistronic, predicted to encode a 71 aa- (p8) and a 98 aa (p11) protein, respectively. It is concluded that PRV has more properties in common with orthoreoviruses than with aquareoviruses