Detection and Identification of the Four Malaria Parasite Species Infecting Humans by PCR Amplification

False-Negative Rapid Diagnostic Tests for Malaria and Deletion of the Histidine-Rich Repeat Region of the hrp2 Gene

“…Re-examination of the blood smears for the 26 smear-positive, RDT-negative specimens excluded falsepositive readings by microscopy. Likewise, PCR amplification with primers for the polymorphic block 2 region of msp1 and species-specific primers for P. falciparum ribosomal DNA showed that P. falciparum DNA was present (consistent with true-positive blood smears) and excluded PCR inhibitors 10,11 as an explanation for the negative hrp2 PCR results (for the 10 smear-positive specimens with false-negative RDTs).…”

“…9 PCR amplification was performed using primers specific for the conserved 5 0 and 3 0 regions of the hrp2 gene that flank the central histidinerich repeat region ( Figure 1 and Table 1). Allotype-specific primers for the polymorphic block 2 region of merozoite surface protein 1 (MSP-1) 10 and species-specific primers for ribosomal DNA 11 were used as controls for smear-positive specimens, which yielded negative results with the HRP2-based RDT to determine whether P. falciparum DNA was present and thus, exclude nonspecific inhibition of the PCR.…”

“…To exclude nonspecific inhibition of the PCR, we used allotype-specific primers for the block 2 region of msp1 and species-specific primers for parasite ribosomal DNA. 10,11 Those results were positive for each of the 10 smear-positive specimens that were negative in the hpr2 PCR.…”

Urban malaria in the Brazilian Western Amazon Region I: high prevalence of asymptomatic carriers in an urban riverside district is associated with a high level of clinical malaria

“…DNA was extracted from blood samples using the phenol-chloroform protocol (Schlichtherle et al 2000). The nested PCR used was based on the 18S rRNA gene target and genus and species-specific primers proposed by Snounou et al (1993) and Snounou (1996) were used with minor modifications, as previously described (Alves et al 2002). Although all inhabitants of the Village were encouraged to participate in the cross-sectional study, participation varied from 40 to 70% of the population in the four surveys.…”

Cross-reactive anti-PfCLAG9 antibodies in the sera of asymptomatic parasite carriers of Plasmodium vivax

“…Malaria infection diagnostic procedures were performed by microscopy examination and nested polymerase chain reaction (PCR) methods. The protocol used was based in Snounou (1996) and used genus-specific (rPLUS5 and rPLUS6) and species-specific (rFAL1,rFAL2, rMAL1, rMAL2, rVIV1 and rVIV2) primers. Briefly, the 20 µL of reaction volume per tube consisted of 250 nm of each primer, 125 µM dNTPs, 2 mM MgCl 2 , 50 mM KCL, 10 mM Tris pH 8.3, 0.4U Taq polymerase (Invitrogen) and 1 µL of genomic DNA.…”