Previous genetic studies demonstrated that survival and proliferation of Plasmodium falciparum parasites is dependent on salvage of essential purines from the host. Plasmodium falciparum, the causative agent of the most lethal form of human malaria lacks the enzymes required for de novo synthesis of purines. Analysis of the hypothetical nucleoside/nucleobase transporter protein, the gene product of PfNT3 (PF14_0662) gene in P. falciparum parasites was carried out by localisation, in view of a novel chemotherapeutic target. Immunoblotting, immunofluorescent and immunoelectron microscopic localization of PfNT3 was demonstrated using polyclonal antiserum in in vitro cultured Plasmodium falciparum parasites, propagated in human red blood cells. PfNT3 protein, the translated product of PfNT3 gene was detected in intraerythrocytic ring, trophozoite, and schizont stages. PfNT3 was localized primarily to the PPM (Parasite Plasma Membrane). The endogenous PfNT3 putative nucleoside transporter with the predominant location to the parasite plasma membrane may serve not only as routes for targeting of purine analogs/cytotoxic agents into the intracellular parasite but may also serve as drug targets. Being genome encoded the vital transporter protein can be prevented from expression by silencing of the gene, validating it to be a novel drug target.
Plasmodium falciparum

No abstract available.
Megakaryocytes ; Plasmodium ; Plasmodium falciparum

No abstract available.
Malaria, Cerebral* ; Plasmodium falciparum*

The response of the malarial parasite, Plasmodium falciparum to a number of Vietnamese medicinal plants in vitro was carried out. The results showed that the ethanol extract of the plant materials has a stronger inhibitory effect on the growth of P. faciparum than the corresponding water extract. Both ethanol and water extracts of the leaves of Dichroa febrifuge Lour. and the ethnologic extracts from the leaves of Parthenium hysterrophorus L. and Harrisonia perforate (Blanco) Merr. have a clear effect on the chloroquine sensitivity as well as the chloroquine resistant P. falciparum strain
Plants, Medicinal ; Antimalarials ; Plasmodium falciparum

PCR-RFLP and DNA sequencing techniques were used for Pyrimethamine (PYR) and Cycloguanil (CYC) resistant mutations. The study results showed that 46 of 58 Plasmodium falciparum isolates were genotype resistant to pyrimethamine (79.31%). Thirty-one isolates were taken in vitro microscopic examination and revealed that 26 of 31 isolates were PYR resistance (83.87%) and 6 of 31 isolates of CYC resistance (19.35%). The resistant levels of these isolates were related to the mutations in DHFR genes
Plasmodium falciparum ; Pyrimethamine ; Chloroguanide ; malaria

Cerebral malaria is a severe neurological complication of Plasmodium falciparum infection. Cerebral malaria can lead to cerebral infarction by several mechanisms including systemic inflammatory response. The systemic inflammatory response is known to rarely occur in Plasmodium vivax infection. We report a patient who developed multiple cerebral infarctions following Plasmodium vivax infection.
Cerebral Infarction ; Humans ; Malaria, Cerebral ; Plasmodium ; Plasmodium falciparum ; Plasmodium vivax

Plasmodium culture in vitro is often used as an antimalarial drug evaluation model, but the lifecycle of P. falciparum culture in vitro tends to be disordered, which affects the research and evaluation of antimalarial drug mechanism in vitro. By combining magnetic bead separation method with sorbitol synchronization method, a synchronization method was constructed to quickly acquire different lifecycles of P. falciparum and obtain large amounts of parasite with a narrow synchronization window in a short period. Furthermore, the dihydroartemisinin(DHA) was used to treat the early trophozoite phase of P. falciparum 3 D7 for 4 h. Then mRNA was extracted and RNA-seq was conducted to analyze the differential expression of mRNA after drug treatment and obtain the differential gene expression profile. Differential expression of up-regulated genes and down-regulated genes was analyzed according to the screening criteria of |log_2FC|>1 and P<0.05. There, 262 genes were up-regulated and 77 genes were down-regulated. GO functional enrichment analysis of all the differentially expressed genes showed that the enrichment items mainly included cell membrane components, transporter activity, serine/threonine kinase activity, Maurer's clefts(MCs), rhoptry, antigen variation and immune evasion. The enrichment of KEGG pathway included malaria, fatty acid metabolism and peroxisome. Protein-protein interaction(PPI) analysis showed that the down-regulated genes in the modules with high degree of association included rhoptry, myosin complex, transporter and other genes related to the important life activities of malaria invasion and immune escape; the up-regulated genes were mainly related to various toxic exportins of malaria, such as PfSBP1 of MCs. qRT-PCR was used to verify the expression level of some genes, and most of the results were the same as the sequencing results. SBP1 was significantly up-regulated, while some antigenic protein expression levels were down-regulated. Above all, key molecules of DHA therapy were mainly involved in the parasites' rhoptry, transporter, antigenic variation, plasmodium exportin. These results offer us many hints to guide the further studies on mechanism of artemisinin and provide a new way for development of new antimalarial drugs.
Animals ; Antimalarials ; Artemisinins ; Erythrocytes ; Plasmodium falciparum ; Transcriptome

We experienced a case of Plasmodium falciparum gametocytemia successfully treated with primaquine in a twenty seven-years old woman. The patient had been admitted due to general malaise after diagosis and treatment of P. falciparum at Tanzania one month ago. On microscopic examination, P. falciparum gametocytemia was seen and treated with mefloquine for one week but gametocytemia was not disappeared. After primaquine treatment for two weeks, she was successfully treated.
Female ; Humans ; Mefloquine ; Plasmodium falciparum* ; Plasmodium* ; Primaquine* ; Tanzania

Artemisinin-based combination therapy (ACT) resistance is widespread throughout the Greater Mekong Subregion. This raises concern over the antimalarial treatment in Thailand since it shares borders with Cambodia, Laos, and Myanmar where high ACT failure rates were reported. It is crucial to have information about the spread of ACT resistance for efficient planning and treatment. This study was to identify the molecular markers for antimalarial drug resistance: Pfkelch13 and Pfmdr1 mutations from 5 provinces of southern Thailand, from 2012 to 2017, of which 2 provinces on the Thai- Myanmar border (Chumphon and Ranong), one on Thai-Malaysia border (Yala) and 2 from non-border provinces (Phang Nga and Surat Thani). The results showed that C580Y mutation of Pfkelch13 was found mainly in the province on the Thai-Myanmar border. No mutations in the PfKelch13 gene were found in Surat Thani and Yala. The Pfmdr1 gene isolated from the Thai-Malaysia border was a different pattern from those found in other areas (100% N86Y) whereas wild type strain was present in Phang Nga. Our study indicated that the molecular markers of artemisinin resistance were spread in the provinces bordering along the Thai-Myanmar, and the pattern of Pfmdr1 mutations from the areas along the international border of Thailand differed from those of the non-border provinces. The information of the molecular markers from this study highlighted the recent spread of artemisinin resistant parasites from the endemic area, and the data will be useful for optimizing antimalarial treatment based on regional differences.
Cambodia ; Drug Resistance ; Laos ; Myanmar ; Parasites ; Plasmodium falciparum ; Plasmodium ; Thailand

Malaria remains a serious public health problem in Shandong Province, China; therefore, it is important to explore the characteristics of the current malaria prevalence situation in the province. In this study, data of malaria cases reported in Shandong during 2012-2014 were analyzed, and Plasmodium species were confirmed by smear microscopy and nested-PCR. A total of 374 malaria cases were reported, 80.8% of which were reported from 6 prefectures. Of all cases, P. falciparum was dominant (81.3%), followed by P. vivax (11.8%); P. ovale and P. malariae together accounted for 6.4% of cases. Notably, for the first time since 2012, no indigenous case had been reported in Shandong Province, a situation that continued through 2014. Total 95.2% of cases were imported from Africa. The ratio of male/female was 92.5:1, and 96.8% of cases occurred in people 20-54 years of age. Farmers or laborers represented 77.5% of cases. No significant trends of monthly pattern were found in the reported cases. All patients were in good condition after treatment, except for 3 who died. These results indicate that imported malaria has increased significantly since 2012 in Shandong Province, especially for P. falciparum, and there is an emergence of species diversity.
Africa ; China* ; Farmers ; Humans ; Malaria* ; Microscopy ; Plasmodium falciparum ; Plasmodium malariae ; Plasmodium ovale ; Plasmodium vivax ; Plasmodium* ; Prevalence ; Public Health