METHODOLOGY: The literatures published after April, 2015 up to December, 2016 on k13 mutant alleles for artemisinin resistance in Plasmodium falciparum and relevant literatures were comprehensively reviewed.
RESULTS: To date, 13 non-synonymous mutations of k13 gene have been observed to have slow parasite clearance. Worldwide mapping of k13 mutant alleles have shown mutants associated with artemisinin resistance were confined to southeast Asia and China and did not invade to African countries. Although in vitro ring stage survival assay of 0-3 h was a recently developed assay, it was useful for rapid detection of artemisinin resistance associated k13 allelic marker in the parasite. Recently, dissemination of k13 mutant alleles was recommended to be investigated by identity of haplotypes. Significant characteristics of well described alleles in the reports were mentioned in this review for the benefit of future studies.
CONCLUSION: According to the updates in the review, it can be concluded artemisinin resistance does not disseminate to India and African countries within short period whereas regular tracking of these mutants is necessary.
METHODOLOGY AND PRINCIPAL FINDINGS: A total of 120 retrospective dengue serum specimens were subjected to serotyping and genotyping by Taqman Real-Time RT-PCR, sequencing and phylogenetic analysis. Subsequently, the dengue serotype and genotype data were statistically analyzed for 101 of 120 corresponding patients' clinical manifestations to generate a descriptive relation between the genetic components and clinical outcomes of dengue infected patients. During the study period, predominant dengue serotype and genotype were found to be DENV 1 genotype I. Additionally, non-severe clinical manifestations were commonly observed in patients infected with DENV 1 and DENV 3. Meanwhile, patients with DENV 2 infection showed significant warning signs and developed severe dengue (p = 0.007). Cases infected with DENV 2 were also commonly presented with persistent vomiting (p = 0.010), epigastric pain (p = 0.018), plasma leakage (p = 0.004) and shock (p = 0.038). Moreover, myalgia and arthralgia were highly prevalent among DENV 3 infection (p = 0.015; p = 0.014). The comparison of genotype-specific clinical manifestations showed that DENV 2 Cosmopolitan was significantly common among severe dengue patients. An association was also found between genotype I of DENV 3 and myalgia. In a similar vein, genotype III of DENV 3 was significantly common among patients with arthralgia.
CONCLUSION: The current data contended that different dengue serotype and genotype had caused distinct clinical characteristics in infected patients.
Objectives: This is a prevalence study that assessed the genetic diversity of chronic hepatitis B patients and coinfection.
Methods: Chronic hepatitis B patients enrolled in this study were tested for antibodies of other hepatitis viruses using ELISA kits. Patient clinical profiles were collected and partial genes of HBV, HCV, and HEV were amplified, sequenced, and analyzed using phylogenetic analysis. The associations between variables were determined using the chi-squared test.
Results: Of the 82 patients recruited for this study, 53.7% were non-cirrhotic, 22.0% cirrhotic, 20.7% acute flare and 3.7% hepatocellular carcinoma. Majority (58%) of patients had a high level of ALT (≥34 U/L). Sequence analysis showed HBV (63.9%) belonged to genotype B, HEV belonged to genotype 4 while HCV belonged to genotype 3a and the genotypes were found to be significantly associated with the clinical stage of the patients (χ2=56.632; p<0.01). Similarly, Hepatitis B e antigen was also found to be significantly associated with the clinical stage of infection (χ2=51.952; p<0.01).
Conclusion: This study revealed that genetic diversity was found to have a significant impact on the severity of infection.
RESULTS: A noticeable variation between the RDT (Alltest Biotech, China) and nPCR results was observed, for RDT 78% (46/59) were P. falciparum positive, 6.8% (4/59) were co-infected with both P. falciparum and Plasmodium vivax, 15.3% (9/59) were negative by the RDT. However, when the nPCR was applied only 44.1% (26/59) and 55.9% (33/59) was P. falciparum positive and negative respectively. The pfhrp2 was further amplified form all nPCR positive samples. Only 17 DNA samples were positive from the 26 positive P. falciparum, interestingly, variation in band sizes was observed and further confirmed by DNA sequencing, and sequencing analysis revealed a high-level of genetic diversity of the pfhrp2 gene in the parasite population from the study area. However, despite extreme sequence variation, diversity of PfHRP2 does not appear to affect RDT performance.
Methods: Two complementary approaches, saturated transposon mutagenesis and spontaneous mutation induction with high concentrations of colistin and polymyxin B, were employed to select for mutations associated with resistance to polymyxins. Mutants were identified using transposon-directed insertion-site sequencing or Illumina WGS. A resistance phenotype was confirmed by MIC and further investigated using RT-PCR. Competitive growth assays were used to measure fitness cost.
Results: A transposon insertion at nucleotide 41 of the pmrB gene (EC958pmrB41-Tn5) enhanced its transcript level, resulting in a 64- and 32-fold increased MIC of colistin and polymyxin B, respectively. Three spontaneous mutations, also located within the pmrB gene, conferred resistance to both colistin and polymyxin B with a corresponding increase in transcription of the pmrCAB genes. All three mutations incurred a fitness cost in the absence of colistin and polymyxin B.
Conclusions: This study identified the pmrB gene as the main chromosomal target for induction of colistin and polymyxin B resistance in E. coli.
METHODS: The cytotoxicity activity was measured using MTS assay. The mode of cell death was analysed by early (phosphatidylserine externalization) and late apoptosis (DNA fragmentation). The caspases 8, 9, 3/7 and apoptotic proteins bax, bcl-2 study were done by western blot and ELISA method.
RESULTS: The methanol extract was found to inhibit 50% growth of T-47D cells at the concentration of 79.43µg/ml respectively after 72hr. From seven fractions, fraction F1, F2 and F3 produced cytotoxicity effects in T-47D cell line with IC50 (72hr) < 30µg/ml. The results obtained by Annexin V/PI apoptosis detection assay and TUNEL assay suggest that active fractions of Vitex rotundifolia induced early and late apoptosis (DNA fragmentation) in T-47D cell line. Moreover, western blot analysis and Caspase GloTM luminescent assay demonstrated that fractions F2 and F3 triggered apoptotic cell death via activation of caspases -8, -9 and -3/7 and up-regulation of Bax and down-regulation of Bcl-2 protein. Furthermore, chemical profiling confirms the presence of potential metabolites (vitexicarpin) in fractions of Vitex rotundifolia.
CONCLUSION: Thus, the present study suggests the remarkable potential of active metabolites in fractions of Vitex rotundifolia as future cancer therapeutic agent for the treatment of breast cancer.
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