[Evaluation of DNA recombinant chitinase fusion protein antigens in serological diagnosis for filariasis].
OBJECTIVE
To evaluate DNA-recombinant chitinase fusion protein antigen in serodiagnosis for Bancroft's filariasis in jirds rats with microfilaremia and normal jirds rats with ELISA, and its prospect in the market to be spread.


METHODS
Oligonucleotide was synthesized with filaria monoclonal antibody (Mf(1))-recognized microfilaria chitinase fusion protein and basic primer recognized by original clonal nucleosides, and amplified with polymerase chain reaction (PCR). PCR products were expressed in Pmal-c vector and purified by affinity chromatography. Experimental animals were inoculated with chitinase fusion protein antigen and infected with larval stage filaria Brugia malayi, respectively. Functional protein molecule of chitinase antigen was analyzed with SDS-PAGE and western blot. Serum level of specific antibody to chitinase antigen was determined by ELISA, and compared with that to microfilaria xt antigen (Mf-xt).


RESULTS
Specific function protein molecule of the above-mentioned chitinase antigen has been identified as 69,000. Serum antibody against chitinase antigen was 100% positive for jirds and patients with microfilaremia, but, that against Mf-xt only 80% positive. Serum antibody against chitinase antigen was negative for all normal jirds and normal persons, but that against Mf-xt had 5% false positive in normal serum. For those with microfilaremia from non-filariasis-prevalent areas, false sero-positivity was 5% and 20% with chitinase antigen and Mf-xt, respectively.


CONCLUSIONS
ELISA with DNA recombinant fusion protein antigen is a sensitive and specific method in serological diagnosis and surveillance for filariasis, with simple, easy and convenient manipulation. It can be used in field serologic surveillance and diagnosis for filariasis during the late phase in control of filariasis and can be spread in good prospects.
Wang
S
S
Guizhou Provincial Institute of Parasitic Diseases, Guiyang 550001.
Xiong
M
M
Liu
T
T
Tang
L
L
Fang
R
R
D000818:Animals; D000911:Antibodies, Monoclonal; D000947:Antigens, Helminth / Q000235:genetics / Q000276:immunology; D017178:Brugia malayi / Q000276:immunology; D002688:Chitinases / Q000235:genetics* / Q000276:immunology; D004274:DNA, Recombinant / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005368:Filariasis / Q000175:diagnosis* / Q000276:immunology / Q000469:parasitology; D005849:Gerbillinae; D008842:Microfilariae / Q000276:immunology; D011993:Recombinant Fusion Proteins / Q000276:immunology; D012698:Serologic Tests
D000911:Antibodies, Monoclonal; D000947:Antigens, Helminth; D004274:DNA, Recombinant; D011993:Recombinant Fusion Proteins; D002688:Chitinases