scholarly journals Drug Resistance Profile and Clonality of Plasmodium Falciparum Parasites in Cape Verde: The 2017 Malaria Outbreak

Author(s):  
Silvânia da Veiga Leal ◽  
Daniel Ward ◽  
Susana Campino ◽  
Ernest Diez Benavente ◽  
Amy Ibrahim ◽  
...  

Abstract BackgroundCape Verde is an archipelago located off the West African coast, and is in a pre-elimination phase of malaria control. Since 2010, less than 20 Plasmodium falciparum malaria cases have been reported annually, except in 2017, when an outbreak in Praia before the rainy season led to 423 autochthonous cases. It is important to understand the genetic diversity of circulating P. falciparum to inform on drug resistance, potential transmission networks, and sources of infection, including parasite importation.MethodsEnrolled subjects involved malaria patients admitted to Dr. Agostinho Neto Hospital at Praia city, Santiago island, Cape Verde, between July and October 2017. Neighbours and family members of enrolled cases were assessed for the presence of anti-P. falciparum antibodies. Sanger sequencing and real time PCR was used to identify SNPs in genes associated with drug resistance (e.g. pfdhfr, pfdhps, pfmdr1, pfk13, pfcrt), and whole genome sequencing data was generated to investigate the population structure of P. falciparum parasites.ResultsWe analysed 190 parasite samples, 187 indigenous and three from imported infections. Malaria cases were distributed throughout Praia city. There were no cases of severe malaria, and all patients had an adequate clinical and parasitological response after treatment. Anti-P. falciparum antibodies were not detected in the 137 neighbours and family members tested. No mutations were detected in pfdhps. The triple mutation S108N/N51I/C59R in pfdhfr and the chloroquine resistant CVIET haplotype in the pfcrt gene were detected in almost all samples. Variations in pfk13 were identified in only one sample (R645T, E668K). The haplotype NFD for pfmdr1 was detected in the majority of samples (89.7%).ConclusionsPolymorphisms in pfk13 associated with ACTs tolerance in Southeast Asia were not detected, but the majority of the tested samples carried the pfmdr1 haplotype NFD and antimalarial associated mutations in the the pfcrt and pfdhfr genes. We performed the first WGS for Cape Verdean parasites that showed that the samples cluster together, have a very high level of similarity and are close to other parasites populations from West Africa.

2021 ◽  
Author(s):  
Silvânia da Veiga Leal ◽  
Daniel Ward ◽  
Susana Campino ◽  
Ernest Diez Benavente ◽  
Amy Ibrahim ◽  
...  

Abstract Background Cape Verde is an archipelago located off the West African coast, and is in a pre-elimination phase of malaria control. Since 2010, less than 20 Plasmodium falciparum malaria cases have been reported annually, except in 2017, when an outbreak in Praia before the rainy season led to 423 autochthonous cases. It is important to understand the genetic diversity of circulating P. falciparum to inform on drug resistance, potential transmission networks, and sources of infection, including parasite importation.Methods Enrolled subjects involved malaria patients admitted to Dr. Agostinho Neto Hospital at Praia city, Santiago island, Cape Verde, between July and October 2017. Neighbours and family members of enrolled cases were assessed for the presence of anti-P. falciparum antibodies. Sanger sequencing and real time PCR was used to identify SNPs in genes associated with drug resistance (e.g. pfdhfr, pfdhps, pfmdr1, pfk13, pfcrt), and whole genome sequencing data was generated to investigate the population structure of P. falciparum parasites.Results We analysed 190 parasite samples, 187 indigenous and three from imported infections. Malaria cases were distributed throughout Praia city. There were no cases of severe malaria, and all patients had an adequate clinical and parasitological response after treatment. Anti-P. falciparum antibodies were not detected in the 137 neighbours and family members tested. No mutations were detected in pfdhps. The triple mutation S108N/N51I/C59R in pfdhfr and the chloroquine resistant CVIET haplotype in the pfcrt gene were detected in almost all samples. Variations in pfk13 were identified in only one sample (R645T, E668K). The haplotype NFD for pfmdr1 was detected in the majority of samples (89.7%).Conclusions Polymorphisms in pfk13 associated with ACTs tolerance in Southeast Asia were not detected, but the majority of the tested samples carried the pfmdr1 haplotype NFD and antimalarial associated mutations in the the pfcrt and pfdhfr genes. We performed the first WGS for Cape Verdean parasites that showed that the samples cluster together, have a very high level of similarity and are close to other parasites populations from West Africa.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Silvania Da Veiga Leal ◽  
Daniel Ward ◽  
Susana Campino ◽  
Ernest Diez Benavente ◽  
Amy Ibrahim ◽  
...  

Abstract Background Cape Verde is an archipelago located off the West African coast and is in a pre-elimination phase of malaria control. Since 2010, fewer than 20 Plasmodium falciparum malaria cases have been reported annually, except in 2017, when an outbreak in Praia before the rainy season led to 423 autochthonous cases. It is important to understand the genetic diversity of circulating P. falciparum to inform on drug resistance, potential transmission networks and sources of infection, including parasite importation. Methods Enrolled subjects involved malaria patients admitted to Dr Agostinho Neto Hospital at Praia city, Santiago island, Cape Verde, between July and October 2017. Neighbours and family members of enrolled cases were assessed for the presence of anti-P. falciparum antibodies. Sanger sequencing and real-time PCR was used to identify SNPs in genes associated with drug resistance (e.g., pfdhfr, pfdhps, pfmdr1, pfk13, pfcrt), and whole genome sequencing data were generated to investigate the population structure of P. falciparum parasites. Results The study analysed 190 parasite samples, 187 indigenous and 3 from imported infections. Malaria cases were distributed throughout Praia city. There were no cases of severe malaria and all patients had an adequate clinical and parasitological response after treatment. Anti-P. falciparum antibodies were not detected in the 137 neighbours and family members tested. No mutations were detected in pfdhps. The triple mutation S108N/N51I/C59R in pfdhfr and the chloroquine-resistant CVIET haplotype in the pfcrt gene were detected in almost all samples. Variations in pfk13 were identified in only one sample (R645T, E668K). The haplotype NFD for pfmdr1 was detected in the majority of samples (89.7%). Conclusions Polymorphisms in pfk13 associated with artemisinin-based combination therapy (ACT) tolerance in Southeast Asia were not detected, but the majority of the tested samples carried the pfmdr1 haplotype NFD and anti-malarial-associated mutations in the the pfcrt and pfdhfr genes. The first whole genome sequencing (WGS) was performed for Cape Verdean parasites that showed that the samples cluster together, have a very high level of similarity and are close to other parasites populations from West Africa.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Karin Wallander ◽  
Jessada Thutkawkorapin ◽  
Ellika Sahlin ◽  
Annika Lindblom ◽  
Kristina Lagerstedt-Robinson

Abstract Background We have previously reported a family with a suspected autosomal dominant rectal and gastric cancer syndrome without any obvious causative genetic variant. Here, we focused the study on a potentially isolated rectal cancer syndrome in this family. Methods We included seven family members (six obligate carriers). Whole-exome sequencing and whole-genome sequencing data were analyzed and filtered for shared coding and splicing sequence and structural variants among the affected individuals. Results When considering family members with rectal cancer or advanced adenomas as affected, we found six new potentially cancer-associated variants in the genes CENPB, ZBTB20, CLINK, LRRC26, TRPM1, and NPEPL1. All variants were missense variants and none of the genes have previously been linked to inherited rectal cancer. No structural variant was found. Conclusion By massive parallel sequencing in a family suspected of carrying a highly penetrant rectal cancer predisposing genetic variant, we found six genetic missense variants with a potential connection to the rectal cancer in this family. One of them could be a high-risk genetic variant, or one or more of them could be low risk variants. The p.(Glu438Lys) variant in the CENPB gene was found to be of particular interest. The CENPB protein binds DNA and helps form centromeres during mitosis. It is involved in the WNT signaling pathway, which is critical for colorectal cancer development and its role in inherited rectal cancer needs to be further examined.


2017 ◽  
Vol 5 (45) ◽  
Author(s):  
Ashraf A. Khan ◽  
Bijay K. Khajanchi ◽  
Sana A. Khan ◽  
Christopher A. Elkins ◽  
Steven L. Foley

ABSTRACT We report here the draft genome sequences of 15 ciprofloxacin-resistant Salmonella enterica strains with resistance to multiple other antibiotics, including aminoglycosides, β-lactams, sulfonamides, tetracycline, and trimethoprim, isolated from different imported foods. Three strains (NCTR75, NCTR281, and NCTR350) showed a high level of ciprofloxacin resistance compared to that of the other isolates. The whole-genome sequencing data provide a better understanding of the antibiotic resistance mechanisms and virulence properties of these isolates.


2016 ◽  
Author(s):  
Lyndal Henden ◽  
Stuart Lee ◽  
Ivo Mueller ◽  
Alyssa Barry ◽  
Melanie Bahlo

AbstractIdentification of genomic regions that are identical by descent (IBD) has proven useful for human genetic studies where analyses have led to the discovery of familial relatedness and fine-mapping of disease critical regions. Unfortunately however, IBD analyses have been underutilized inanalysis of other organisms, including human pathogens. This is in part due to the lack of statistical methodologies for non-diploid genomes in addition to the added complexity of multiclonal infections. As such, we have developed an IBD methodology, called isoRelate, for analysis of haploid recombining microorganisms in the presence of multiclonal infections. Using the inferred IBD status at genomic locations, we have also developed a novel statistic for identifying loci under positive selection and propose relatedness networks as a means of exploring shared haplotypes within populations. We evaluate the performance of our methodologies for detecting IBD and selection, including comparisons with existing tools, then perform an exploratory analysis of whole genome sequencing data from a global Plasmodium falciparum dataset of more than 2500 genomes. This analysis identifies Southeast Asia as havingmany highly related isolates, possibly as a result of both reduced transmission from intensified control efforts and population bottlenecks following the emergence of antimalarial drug resistance. Many signals of selection are also identified, most of which overlap genes that are known to be associated with drug resistance, in addition to two novel signals observed in multiple countries that have yet to be explored in detail. Additionally, we investigate relatedness networks over the selected loci and determine that one of these sweeps has spread between continents while the other has arisen independently in different countries. IBD analysis of microorganisms using isoRelate can be used for exploring population structure, positive selection and haplotype distributions, and will be a valuable tool for monitoring disease control and elimination efforts of many diseases.


2019 ◽  
Author(s):  
Mukul Rawat ◽  
Abhishek Kanyal ◽  
Aishwarya Sahasrabudhe ◽  
Shruthi S. Vembar ◽  
Jose-Juan Lopez-Rubio ◽  
...  

AbstractPlasmodium falciparumhas evolved resistance to almost all front-line drugs including artemisinins, which threatens malaria control and elimination strategies. Oxidative stress and protein damage responses have emerged as key players in the generation of artemisinin resistance. In this study, we show that PfGCN5, a histone acetyltransferase, binds to the stress responsive and multi-variant family genes in poised state and regulates their expression under stress conditions. We have also provided biochemical and cellular evidences that PfGCN5 regulates stress responsive genes by acetylation of PfAlba3. Furthermore, we show that upon artemisinin exposure, genome-wide binding sites for PfGCN5 are increased and it is directly associated with the genes implicated in artemisinin resistance generation like BiP and TRiC chaperone. Moreover, inhibition of PfGCN5 in artemisinin resistant parasites, Kelch13 mutant, K13I543T and K13C580Y (RSA∼ 25% and 6%, respectively) reverses the sensitivity of the parasites to artemisinin treatment indicating its role in drug resistance generation. Together, these findings elucidate the role of PfGCN5 as a global chromatin regulator of stress-responses with potential role in modulating artemisinin drug resistance, and identify PfGCN5 as an important target against artemisinin resistant parasites.Author SummaryMalaria parasites are constantly adapting to the drugs we used to eliminate them. Thus, when we use the drugs to kill parasites; with time, we select the parasites with the favourable genetic changes. Parasites develop various strategies to overcome exposure to the drugs by exhibiting the stress responses. The changes specific to the drug adapted parasites can be used to understand the mechanism of drug resistance generation. In this study, we have identified PfGCN5 as a global transcriptional regulator of stress responses inPlasmodium falciparum. Inhibition of PfGCN5 reverses the sensitivity of the parasites to the artemisinin drug and identify PfGCN5 as an important target against artemisinin resistant parasites.


Author(s):  
Sofonias K Tessema ◽  
Nicholas J Hathaway ◽  
Noam B Teyssier ◽  
Maxwell Murphy ◽  
Anna Chen ◽  
...  

Abstract Background Targeted next-generation sequencing offers the potential for consistent, deep coverage of information-rich genomic regions to characterize polyclonal Plasmodium falciparum infections. However, methods to identify and sequence these genomic regions are currently limited. Methods A bioinformatic pipeline and multiplex methods were developed to identify and simultaneously sequence 100 targets and applied to dried blood spot (DBS) controls and field isolates from Mozambique. For comparison, whole-genome sequencing data were generated for the same controls. Results Using publicly available genomes, 4465 high-diversity genomic regions suited for targeted sequencing were identified, representing the P. falciparum heterozygome. For this study, 93 microhaplotypes with high diversity (median expected heterozygosity = 0.7) were selected along with 7 drug resistance loci. The sequencing method achieved very high coverage (median 99%), specificity (99.8%), and sensitivity (90% for haplotypes with 5% within sample frequency in dried blood spots with 100 parasites/µL). In silico analyses revealed that microhaplotypes provided much higher resolution to discriminate related from unrelated polyclonal infections than biallelic single-nucleotide polymorphism barcodes. Conclusions The bioinformatic and laboratory methods outlined here provide a flexible tool for efficient, low-cost, high-throughput interrogation of the P. falciparum genome, and can be tailored to simultaneously address multiple questions of interest in various epidemiological settings.


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