Administration of yeast glucan enhances survival and some non-specific and specific immune parameters in carp (Cyprinus carpio) infected with Aeromonas hydrophila.
Effects of beta-glucan administration on survival and immune modulations were studied in Cyprinus carpio against the bacterial pathogen, Aeromonas hydrophila. Beta-glucan was extracted from Saccharomyces cervisiae and purified. A virulent strain of the pathogen A. hydrophila was collected from infected fish. Different concentrations of beta-glucan were administered to test animals on day 1, 3 and 5 through different routes (intraperitoneal injection (ip), bathing and oral administration). Control and test animals were challenged by ip injection of LD50 concentration of A. hydrophila on day 7 and mortality was observed and Relative Percent Survival (RPS) was calculated. Intraperitoneal injection of 500 microg of glucan significantly enhanced the RPS; bathing and oral administration of glucan did not influence the RPS. On day 7, test animals injected with 100, 500 and 1000 microg of glucan had a significant increase in total blood leucocyte counts and an increase in the proportion of neutrophils and monocytes. Superoxide anion production by kidney macrophages was also elevated. RT-PCR and northern blot analysis of interleukin-1 mRNA showed elevated expression in kidney on day 7 in fish injected with glucan. Glucan had an adjuvant effect on antibody production as pretreatment by injection of 100-1000 microg glucan/fish resulted in the highest antibody titer against A. hydrophila following vaccination. Classical and alternative complement pathways were not affected by glucan administration by any of the three routes.
Selvaraj
V
V
Spic Research and Development, Spic Limited, Tuticorin 628 005, Tamilnadu, India. sselvarajv@yahoo.co.in
Sampath
K
K
Sekar
V
V
D016980:Aeromonas hydrophila; D000818:Animals; D015152:Blotting, Northern / Q000662:veterinary; D002347:Carps; D003170:Complement Pathway, Alternative / Q000276:immunology; D017931:DNA Primers; D018076:DNA, Complementary / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D005393:Fish Diseases / Q000276:immunology* / Q000382:microbiology*; D016905:Gram-Negative Bacterial Infections / Q000276:immunology / Q000662:veterinary*; D007375:Interleukin-1 / Q000378:metabolism; D007668:Kidney / Q000166:cytology / Q000378:metabolism; D007958:Leukocyte Count / Q000662:veterinary; D008264:Macrophages / Q000187:drug effects; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D012441:Saccharomyces cerevisiae / Q000737:chemistry; D013481:Superoxides / Q000378:metabolism; D016019:Survival Analysis; D047071:beta-Glucans / Q000008:administration & dosage / Q000494:pharmacology*
D017931:DNA Primers; D018076:DNA, Complementary; D007375:Interleukin-1; D047071:beta-Glucans; D013481:Superoxides