title: Prevalence of drug resistance associated mutations in Plasmodium vivax against sulphadoxine-pyrimethamine in southern Pakistan.
abstract: BACKGROUND
  In Pakistan, Plasmodium vivax and Plasmodium falciparum co-exist and usage of sulphadoxine-pyrimethamine (SP) against P. falciparum exposes P. vivax to the drug leading to generation of resistant alleles. The main aim of this study was to investigate frequency distribution of drug resistance associated mutations in pvdhfr, pvdhps genes and provide baseline molecular epidemiological data on SP-associated resistance in P. vivax from southern Pakistan.
  
  
  METHODS
  From January 2008 to May 2009, a total of 150 samples were collected from patients tested slide-positive for P. vivax, at the Aga Khan University Hospital, Karachi, or its collection units located in Baluchistan and Sindh Province. Nested PCR using pvdhfr and pvdhps specific primers was performed for all samples.91.3% (137/150) of the samples were tested PCR positive of which 87.3% (131/137) were successfully sequenced. Sample sequencing data was analysed and compared against wild type reference sequences.
  
  
  RESULTS
  In dhfr, mutations were observed at codons F57L, S58R and S117N/T. Novel non-synonymous mutations were observed at codon positions N50I, G114R and E119K while a synonymous mutation was observed at codon position 69Y. In dhps, mutations were observed at codon position A383G and A553G while novel non-synonymous mutations were observed at codon positions S373T, E380K, P384L, N389T, V392D, T393P, D459A, M601I, A651D and A661V.
  
  
  CONCLUSIONS
  This is the first report from southern Pakistan on SP resistance in clinical isolates of P. vivax. Results from this study confirm that diverse drug resistant alleles are circulating within this region.
authors.affiliation: Department of Pathology and Microbiology, Aga Khan University, Stadium Road, Karachi, Pakistan.
authors.forename: Afsheen
authors.initials: A
authors.lastname: Raza
authors.forename: Najia K
authors.initials: NK
authors.lastname: Ghanchi
authors.forename: Muhammad Shahzeb
authors.initials: MS
authors.lastname: Khan
authors.forename: Mohammad Asim
authors.initials: MA
authors.lastname: Beg
mesh_terms: D000962:Antimalarials / Q000494:pharmacology*; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D004094:Dihydropteroate Synthase / Q000235:genetics; D004338:Drug Combinations; D004351:Drug Resistance; D005787:Gene Frequency; D006785:Hospitals, University; D006801:Humans; D016780:Malaria, Vivax / Q000469:parasitology*; D009154:Mutation; D010154:Pakistan; D010966:Plasmodium vivax / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D015995:Prevalence; D015800:Protozoan Proteins / Q000235:genetics; D011739:Pyrimethamine / Q000494:pharmacology*; D017422:Sequence Analysis, DNA; D013413:Sulfadoxine / Q000494:pharmacology*; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics
chemical_list: D000962:Antimalarials; D016054:DNA, Protozoan; D004338:Drug Combinations; D015800:Protozoan Proteins; C001205:fanasil, pyrimethamine drug combination; D013413:Sulfadoxine; D013762:Tetrahydrofolate Dehydrogenase; D004094:Dihydropteroate Synthase; D011739:Pyrimethamine
references.citation: Antimicrob Agents Chemother. 2003 May;47(5):1514-21
references.pmid: 12709316
references.citation: Am J Trop Med Hyg. 2008 Mar;78(3):462-7
references.pmid: 18337344
references.citation: Int J Infect Dis. 2008 Jan;12(1):37-42
references.pmid: 17576086
references.citation: Trends Parasitol. 2007 May;23(5):213-22
references.pmid: 17368986
references.citation: Antimicrob Agents Chemother. 2004 Jun;48(6):2214-22
references.pmid: 15155224
references.citation: J Clin Pathol. 1996 Jul;49(7):533-8
references.pmid: 8813948
references.citation: Antimicrob Agents Chemother. 2005 Feb;49(2):733-40
references.pmid: 15673758
references.citation: BMC Public Health. 2012 Nov 01;12:941
references.pmid: 23116148
references.citation: Antimicrob Agents Chemother. 2007 Mar;51(3):857-63
references.pmid: 17194833
references.citation: J Antimicrob Chemother. 2012 Feb;67(2):367-74
references.pmid: 22086859
references.citation: Mem Inst Oswaldo Cruz. 2011 Aug;106 Suppl 1:130-3
references.pmid: 21881767
references.citation: Malar J. 2011 Apr 24;10:102
references.pmid: 21513569
references.citation: Malar J. 2009 Jan 28;8:20
references.pmid: 19175936
references.citation: Korean J Parasitol. 2012 Dec;50(4):379-84
references.pmid: 23230341
references.citation: EMBO J. 1998 Jul 15;17(14):3807-15
references.pmid: 9669998
references.citation: Br Med Bull. 1998;54(3):703-15
references.pmid: 10326295
references.citation: Malar J. 2008 Feb 26;7:35
references.pmid: 18302746
references.citation: Am J Trop Med Hyg. 2009 Sep;81(3):525-8
references.pmid: 19706926
references.citation: Acta Trop. 2010 Sep;115(3):288-92
references.pmid: 20412783
references.citation: Exp Parasitol. 2012 Dec;132(4):410-6
references.pmid: 23043980
references.citation: Mol Microbiol. 2007 Jul;65(2):231-49
references.pmid: 17630968
references.citation: Pharmacol Rev. 2005 Mar;57(1):117-45
references.pmid: 15734729
references.citation: Proc Natl Acad Sci U S A. 2002 Oct 1;99(20):13137-41
references.pmid: 12198181
references.citation: Exp Parasitol. 2011 Jan;127(1):167-72
references.pmid: 20655913
references.citation: East Mediterr Health J. 2010;16 Suppl:S54-60
references.pmid: 21495589
references.citation: Malar J. 2011 Jan 28;10:18
references.pmid: 21272384
references.citation: JAMA. 2007 May 23;297(20):2201-9
references.pmid: 17519409
references.citation: Malar J. 2010 Mar 14;9:75
references.pmid: 20226087
references.citation: Am J Trop Med Hyg. 2006 Oct;75(4):617-21
references.pmid: 17038682
references.citation: Parasitol Res. 2005 Jul;96(5):321-5
references.pmid: 15924223
references.citation: Bull World Health Organ. 2008 Aug;86(8):650-2
references.pmid: 18797627
references.citation: J Infect Dis. 2004 Feb 15;189(4):744-50
references.pmid: 14767830
references.citation: Antimicrob Agents Chemother. 2005 Oct;49(10):4393-5
references.pmid: 16189131