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Efficacy and Safety of an Oral Somatostatin DNA Vaccine without Antibiotic Resistance Gene in Promoting Growth of Piglets
Author(s) -
Han Y.G.,
Liang A.X.,
Han L.,
Guo A.Z.,
Jiang X.P.,
Yang L.G.
Publication year - 2014
Publication title -
scandinavian journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.934
H-Index - 88
eISSN - 1365-3083
pISSN - 0300-9475
DOI - 10.1111/sji.12155
Subject(s) - somatostatin , dna vaccination , bacteria , antibiotics , plasmid , antibody , biology , recombinant dna , microbiology and biotechnology , gene , immunization , endocrinology , immunology , biochemistry , genetics
This study aimed to evaluate the efficacy and safety of an oral DNA vaccine against somatostatin ( SS ) (p GS /2 SS ‐asd, encoding two copies of somatostatin genes) mediated by attenuated S almonella choleraesuis C 500 without antibiotic resistance gene on piglets growth. A total of 50 piglets were uniformly divided into five groups. The animals in the first three groups were orally given vaccine in dose of either 5 × 10 10 , 5 × 10 9 or 5 × 10 8 colony‐forming units (CFU). The remaining two groups were orally administered with either bacteria C 500 (containing p VAX ‐asd plasmid without somatostatin gene) or phosphate‐buffered saline (PBS) as controls. The results indicated that the vaccine induced SS ‐specific antibodies in a dose‐dependent pattern. Compared with the PBS control, animals in the high‐dose group showed lower SS levels and higher growth hormone ( GH ) levels in sera. Average daily gain of animals in the high‐dose group was increased by 32.88% and 26.46% during 4 and 8 weeks, respectively. Anti‐ SS antibodies were positively correlated with either GH levels or average daily gain at week 8 after primary immunization ( P < 0.05). Faecal, soil and water samples originating from immunized piglets and surrounding environment were collected. The target gene (the fusion gene GS /2 SS ) of C 500 (p GS /2 SS ‐asd) was not detected by PCR amplification in these samples, indicating that the surrounding environment was not contaminated by residual recombinant bacteria. In conclusion, the vaccine without antibiotic resistance gene is attributable to improve growth performance of piglets through an influence on GH secretion. Moreover, the immunization did not contaminate the surrounding environment of animals.