American Journal of Research Communication www.usa-journals.com Shayo, et al., 2014: Vol 2(11) 52 ajrc.journal@gmail.com Molecular marker of Plasmodium falciparum resistance to chloroquine (Pfcrt) in an area with long history of antimalarial resistance Alex Shayo 1* , Deus Ishengoma 2 , Vito Baraka 2 , Rashid Madebe 2 , Francis Shahada 1 , and Joram Buza 1 1 The Nelson Mandela African Institution of Science and Technology, P.O.BOX 447, Arusha, Tanzania 2 National Institute for Medical Research, Tanga Medical Research Centre, P.O, BOX 5004, Tanga, Tanzania *Corresponding author: Alex Shayo Tel: +255767383574; Fax: 0736601673, Email: alex.shayo@gmail.com Abstract Background High levels Plasmodium falciparum resistance to Chloroquine (CQ) compelled Tanzania to replace CQ with Suphadoxine-pyrimethamine (SP) as first-line antimalarial in 2001 which was however replaced with Artemether Lumefantrine (AL) in 2006. Studies in Malawi have shown sufficient recovery of CQ-sensitivity after its withdrawal warranting re-using CQ in combination with other antimalarials in the future. This paper assessed the level of CQ resistance at molecular level in an area with long history of antimalarial resistance in North- eastern Tanzania. Materials and Methods Samples were obtained from patients recruited in a clinical trial to assess in vivo efficacy of AL at Mkuzi health centre in Muheza district, North-eastern Tanzania. DNA was extracted from venous blood using Qiagen extraction midi kit. The samples were analyzed for single nucleotide polymorphisms (SNPs) in the P. falciparum CQ resistance transporter gene (Pfcrt; codons 72–76) using polymerase chain reaction (PCR) and sequence-specific oligonucleotide probe (SSOP) enzymelinked immunosorbent assay (ELISA). Prevalence of Pfcrt haplotypes before and after treatment samples was compared.