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Volume 6
Journal of Infectious Diseases and Therapy
ISSN: 2332-0877
Infection Congress 2018
March 01-02, 2018
March 01-02, 2018 Berlin, Germany
5
th
International Congress on
INFECTIOUS DISEASES
Changing
Plasmodium falciparum
genotypes during long term and short time culture in drug free
media
Redemptah Yeda, Charles Okudo, Agnes C Cheruiyot, Dennis Juma, Benjamin Opot, Gladys Chemwor, Lorna J Chebon, Ben Andagalu, Hoseah M Akala
and
Managbanag Jim Ray
United States Army Medical Research Directorate-Kenya Medical Research Institute, Kenya
P
arasite culture assay is an important tool for malaria drug resistance surveillance. This assay usually leads to the large-scale
production of cultured parasites. Consequently, the nature and longevity of parasite genotypes are monitored without
influence from the host factors. Here, we set out to study the genotypic and phenotypic dynamics and stability of field isolates
adapted in continuous cultures. Three field isolates collected from patients presenting with uncomplicated malaria in high
transmission area were maintained in drug-free continuous culture media period spanning 90 days. Aliquots picked at
intervals of 24-48 hours gave 56 samples from each of the isolate within the 90 days period. Each aliquot was regarded as
a separate parasite sample and genotyped using 12 microsatellite (MS) markers. Further, single nucleotide polymorphism
(SNP) analyses of 23 drug resistance markers were done. The 50% inhibitory concentrations (IC50) against four antimalarial
drugs were estimated in some of the samples at aliquoting time-points that coincided with parasitemia levels greater than 3%.
Samples from each patient (parasite-line) were compared as they were passed through the continuous culture. Data revealed
genotypic and phenotypic profiles for the three parasite-lines fluctuated from one generation to the next with no specific
pattern or periodicity. Multilocus analysis revealed that of the three parasite-lines showed genetic diversity and structure. SNP/
MS changes occurred simultaneously in the parasite generation. The mean IC50 for the four drugs tested in the three parasite
lines changed significantly from generation to generation. Our study revealed parasite genetic and phenotypic characteristics
fluctuates in short-and long-term cultures, which indicates that parasite genetic information obtained even in short cultures
is likely to be different from that of the natural infection parasites. These findings endorse ex vivo analyses of parasites in real-
time is important in formulation of anti-malaria drug policies
.
rambogo8285@gmail.comJ Infect Dis Ther 2018, Volume 6
DOI: 10.4172/2332-0877-C1-039