02705     2200241   4500001002100000005001500021035002000036245014000056700001900196700001900215700007400234700001300308700006400321250003800385260004500423300000700468084001500475082001500490008003900505520188500544100001902429990001502448INLIS00000000001602920250108024434  a0010-07210005611 aFractionation, identification and vaccination efficacy of native antigens from the screwworm fly, Chrysomya bezziana. /cRiding, George  aPearson, Roger  aWijffels, Gene  aWilladsen, Peter(CSIRO Livestock, Queensland Australia)Muharsini, Sri  aSukarsih  aSatria, Edy(Balai Penelitian Veteriner, Bogor (Indonesia)).  aJurnal Ilmu Ternak dan Veteriner.  aBalai Penelitian Veteriner, Bogor,c2000  a10  aARTVET0559  aARTVET0559250108                |          | |    aProteases of larval excretory/secretory material and proteins of the peritrophic membrane are the most intensively studied
sources of potential protective antigens from the sheep blowfly Lucilia cuprina. Their importance in the screwworm fly
Chrysomya bezziana has now been investigated. Purified serine proteases from Chrysomya bezziana were tested for their
potential as vaccine antigens in sheep, efficacy being assessed by in vitro and in vivo assays with larval Chrysomya bezziana. No
effect of vaccination was observed by the in vitro assay. However, in the in vivo challenge, larval weights were diminished in the
vaccinated sheep, although larval recoveries increased marginally. Vaccination with Chrysomya bezziana peritrophic membrane
does induce an effective immune response against the parasite resulting in a significant reduction in larval growth and
considerable larval mortality in the in vitro assay. Sequential fractionation of the peritrophic membrane with various surfactants
and chaotrophic agents of increasing solubilisation capacity resulted in the separation of discrete groups of proteins. The groups
of fractionated proteins were tested in a vaccination trial in sheep with vaccine efficacy assessed by in vitro assays. The urea
extract, guanidine-HCl extract and SDS soluble fraction each induced significant levels of protection against Chrysomya
bezziana larvae but the effects were poorer than those obtained from vaccination with whole, native peritrophic membrane.
Several major proteins selected from the three most protective fractions were purified by SDS polyacrylamide gel
electrophoresis. Since insufficient quantities of these proteins were available for vaccination trials, they were either sequenced
directly from the N-terminus or subjected to endoproteinase Lys-C digestion, followed by peptide purification and amino acid0 aRiding, George  aARTVET0559