Volume 60, Issue 3
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645


The drug sensitivity characteristics and Plasmodium falciparum pfmdr1 status of five isolates of P. falciparum recently isolated from patients presenting for treatment from the Thailand/Myanmar border have been investigated. The aim of the study was to avoid the criticisms of some earlier studies by focusing on newly collected isolates from a specific geographic location. Three of the isolates studied exhibited clear resistance to chloroquine similar to that observed in the K1 Thai standard isolate obtained in the 1970s, and the other two isolates were of intermediate sensitivity to chloroquine with concentrations of drug that inhibit parasite growth by 50% of 50 and 43 nmol. The sensitivity of all isolates was enhanced by verapamil but we found no clear association between chloroquine sensitivity and gene copy number or intra-allelic variation of pfmdr1. In contrast, clear cross-resistance was seen between mefloquine and halofantrine, with the most sensitive isolates carrying the K1 mutation in pfmdr1.


Article metrics loading...

The graphs shown below represent data from March 2017
Loading full text...

Full text loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error