Identification ofRiemerella anatipestifergenes differentially expressed in infected duck livers by the selective capture of transcribed sequences technique

Abstract

Riemerella anatipestifer is the causative agent of duck septicaemia. Determination of R. anatipestifer virulence mechanisms will help us to effectively control this contagious agent. The differentially expressed gene profile of R. anatipestifer in infected duck livers was therefore identified and compared with in vitro cultures by selective capture of transcribed sequences analysis. A total of 48 genes were identified, of which 43 were genes that encode enzymes for amino acid biosynthesis and metabolism, intermediary metabolism, and energy metabolism, or proteins for regulatory adaptive responses, general microbial stress response, transport proteins and secreted proteinases. Five were unknown, novel genes. Eight genes representing the categories were randomly chosen and verified by real-time reverse transcriptase-polymerase chain reaction analysis. All were upregulated by R. anatipestifer in infected duck livers, with changes ranging from 1.44-fold to 4.62-fold compared with in vitro cultures. The results from the present study revealed a gene expression profile of R. anatipestifer in infected duck livers. The unknown but novel genes may be potential novel virulence factors for R. anatipestifer. In conclusion, the data from this study will provide a molecular basis for further study of R. anatipestifer pathogenesis.

Genome Sequence of Poultry Pathogen Riemerella anatipestifer Strain RA-YM

“…Presently, 21 serotypes of R. anatipestifer have been identified and no significant cross-protection was reported (10,12,13). Despite the devastating losses it causes in poultry production, not much is known about the pathogenesis and few data on virulence factors are available (4,16,18). Here, we sequenced the genome of R. anatipestifer strain RA-YM, a highly virulent field isolate of serotype 1 (9).…”

Protein Expressions and Their Immunogenicity from Riemerella anatipestifer Cultured in Iron Restriction Medium

“…At seven-day-old, they were then divided into five groups with six ducklings, each our groups were subcutaneously immunized with 500 µg substance as fllows: (1) recombinant Riean_1750 protein, (2) recombinant Riean_1752 protein, (3) recombinant two novel protein mixture, (4) and (5) phosphate buffer solution (PBS), in Freund's complete adjuvant (Sigma) and boosted twice with 500 µg recombinant protein in Freund's incomplete adjuvant (Sigma) on day 14 and day 21. The LD50 of R. anatipestifer was 1×10 9 CFU (data not shown) and the challenge dose was set to double LD50 acording to the previous data [20], [21]. The ducklings of (1),(2),(3),(4) group were challenged by subcutaneous injections with 2 mL inoculum (1×10 9 CFU/mL) of the serotype strain 1 at the left or right proximal femur on day 28, and the ducklings of (5) group were injected with PBS.…”

Selective Capture of Transcribed Sequences: A Promising Approach for Investigating Bacterium-Insect Interactions

“…Further analyses of these identified genes have indicated possible mechanistic associations between the identified gene products in metabolic pathways, providing an interactive model of pathogenesis for each bacterium species. Success of SCOTS in other bacterial pathogenic interactions includes Moraxella osloensis in slugs [ 41 ], Streptococcus suis in pigs [ 42 ], Ehrlichia ruminantium in ruminants [ 43 ], Riemerella anatipestifer in ducks [ 44 ], and Haemophilus parasuis in necrotic porcine [ 45 ], etc .…”