Molecualar diagnosis for vector mosquitoes Molecualr diagnosis for filarial parasites

Molecular diagnosis of Vector Mosquitoes

• The Centre has developed rDNA-ITS2-PCR assay for two of the sibling species of An. fluviatilis , a major vector of malaria in Central and Northern parts of India.

• The rDNA-ITS2 region based PCR assay showed that a PCR product of size 620 bp in species B a salt water form and a vector of malaria was distinct enough to permit its differentiation from the other members of the Anopheles subpictus complex A, C and D.

• Two genes specific for infective stage (L3) larvae of Wuchereria bancrofti were identified, sequenced and developed as probes for detecting vector infectivity by RT-PCR assay.

• A monoclonal antibody specific to e/s antigens of fourth stage larvae of Wuchereria bancrofti was developed which has potential application in the early diagnosis of filarial infection.

• PCR assays developed for detecting Wuchereria bancrofti and Brugia malayi infection in respective vectors were evaluated and found to be highly specific. Sensitivity-wise B. malayi PCR assay was found to be equal to the conventional technique and that of Wuchereria bancrofti was less.

• A simple, efficient, rapid and cost-effective method for the extraction of DNA from a single mf in pools of 25 mosquitoes, stable for about a year and suitable for PCR amplification yielding a species specific band of 322 bp with primers specific for Brugia malayi was developed.

• Random Amplified Fragment (RAPD) analysis of Wuchereria bancrofti from three villages showed heterogeneity among parasite population.

• The sensitivity and specificity of the day blood Immunochormatography Card Test (ICT) for bancroftian filariasis was 98.5% and 100% respectively compared to the finger prick thick smear night blood test.

• The ICT is suitable for delimitation and for spot treatment decision as the result is available within 2-5 min of testing.

• The sensitivity and specificity of Og4C3 monoclonal antibody ELISA test were 100% and 97% respectively compared to the finger prick thick smear night blood test.

• The Og4C3 kit is suitable for quantifying antigen levels for monitoring and evaluation of control programmes.

• Two conserved antigens of Plasmodium falciparum which hold promise as vaccine candidates were expressed in E.coli.

• These were found to contain novel genes, which were conserved across different species of Plasmodium.