Review Article

Current Bancroftian Filariasis Elimination on Thailand-Myanmar Border: Public Health Challenges toward Postgenomic MDA Evaluation

Figure 8

Detection and identification of benzimidazole susceptibility and resistance in W. bancrofti population by allele-specific nested multiplex PCR assay. (a) IBF microfilaremic carriers used in testing a hypothesis that W. bancrofti parasite population harbor benzimidazole susceptible phenotype although the adaptation of parasite population is influenced by chain migration of MMWs over a space and time as described in Figure 7. (b) Fitness of W. bancrofti parasite population could yield descendants of parasites with allele frequencies in dynamic cross-border MMWs under suppression of Thai/Myanmar PELF. An individual carrying one dominant and one recessive allele (Sr) is referred to as heterozygous dominant. An individual has two dominant alleles (SS), the condition is referred to as BZ-susceptible homozygous allele; an individual with two recessive alleles (rr) is called BZ-resistant homozygous allele. (c) Allele-specific nested multiplex PCR assay whose amplification conditions have been previously established by Bhumiratana et al. (2010) [19] and Pechgit et al. (2011) [24] employs the primers BT121 and BT122 originally derived from the exon 5 of W. bancrofti β-tubulin gene hypothetically conferring a single-point mutation at codon F200Y. Only the primers BT121R and BT122S are newly developed for this investigation.