scholarly journals Is genetic diversity of Plasmodium falciparum suggestive of malaria endemic zone in West Africa? An attempt to respond by a cross-sectional comparative study between Senegal and Nigeria

Author(s):  
Mary Aigbiremo Oboh ◽  
Tolla Ndiaye ◽  
Khadim Diongue ◽  
Yaye D Ndiaye ◽  
Mouhamad Sy ◽  
...  

Background: Characterization of malaria parasite populations in different endemic settings (from low to high) could be helpful for ascertaining the progress of malaria interventions in endemic settings. The present study aims to compare Plasmodium falciparum parasite population structure between two West African countries with very different level of endemicity using P. falciparum allelic polymorphic markers: msp1 and msp2. Methods: Parasite genomic DNA was extracted from 187 dried blood spot collected from confirmed uncomplicated P. falciparum malaria infected patients in Senegal (94) being at the pre-elimination stage in most part of the country and Nigeria (93) which is still at the control stage. Allelic polymorphism of msp1 and msp2 genes were assessed by nested PCR. Results: In Senegal as well as in Nigeria, K1 and IC3D7 allelic families were the most represented for msp1 and msp2 genes respectively. A higher multiplicity of infection (MOI) was found in both study sites in Senegal (Thies:1.51/2.53; Kedougou:2.2/2.0 for msp 1/2) than from sites in Nigeria (Gbagada: 1.39/1.96; Oredo: 1.35/1.75]). The heterozygosity of msp 1 gene was higher in P. falciparum isolates from Senegal (Thies: 0.62; Kedougou: 0.53) than isolates from Nigeria (Gbagada: 0.55; Oredo: 0.50). In Senegal, K1 alleles were associated with heavy (28) than with moderate (18) infections, in Nigeria however, equal proportions of K1 were observed in both infection types. The IC3D7 subtype allele of the msp 2 family showed high occurrence in heavily infected individuals from both countries (Senegal- 32; Nigeria- 26) than in the moderately infected participants. Conclusion: With the unusual high genetic diversity obtained in low endemic setting in Senegal and low genetic diversity in a high endemic Nigerian setting, multiple holistic approach should be employed in evaluating the actual transmission of a place in order to effectively direct control measures.

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Mary A. Oboh ◽  
Tolla Ndiaye ◽  
Khadim Diongue ◽  
Yaye D. Ndiaye ◽  
Mouhamad Sy ◽  
...  

Abstract Background Characterizing the genetic diversity of malaria parasite populations in different endemic settings (from low to high) could be helpful in determining the effectiveness of malaria interventions. This study compared Plasmodium falciparum parasite population diversity from two sites with low (pre-elimination) and high transmission in Senegal and Nigeria, respectively. Methods Parasite genomic DNA was extracted from 187 dried blood spot collected from confirmed uncomplicated P. falciparum malaria infected patients in Senegal (94) and Nigeria (93). Allelic polymorphism at merozoite surface protein 1 (msp1) and merozoite surface protein- 2 (msp2) genes were assessed by nested PCR. Results The most frequent msp1 and msp2 allelic families are the K1 and IC3D7 allelotypes in both Senegal and Nigeria. Multiplicity of infection (MOI) of greater that 1 and thus complex infections was common in both study sites in Senegal (Thies:1.51/2.53; Kedougou:2.2/2.0 for msp1/2) than in Nigeria (Gbagada: 1.39/1.96; Oredo: 1.35/1.75]). The heterozygosity of msp1 gene was higher in P. falciparum isolates from Senegal (Thies: 0.62; Kedougou: 0.53) than isolates from Nigeria (Gbagada: 0.55; Oredo: 0.50). In Senegal, K1 alleles was associated with heavy than with moderate parasite density. Meanwhile, equal proportions of K1 were observed in both heavy and moderate infection types in Nigeria. The IC3D7 subtype allele of the msp2 family was the most frequent in heavily parasitaemic individuals from both countries than in the moderately infected participants. Conclusion The unexpectedly low genetic diversity of infections high endemic Nigerian setting compared to the low endemic settings in Senegal is suggestive of possible epidemic outbreak in Nigeria.


Open Medicine ◽  
2006 ◽  
Vol 1 (4) ◽  
pp. 392-398
Author(s):  
Kazima Bulayeva ◽  
John McGrath

AbstractWhile the season-of-birth effect is one of the most consistent epidemiological features of schizophrenia, there is a lack of consistency with respect to the interaction between season of birth and family history of schizophrenia. Apart from family history, measures related to consanguinity can be used as proxy markers of genomic heterogeneity. Thus, these measures may provide an alternate, indirect index of genetic susceptibility. We had the opportunity to explore the interaction between season of birth and measure of consanguinity in well-described genetic isolates in Daghestan, some of which are known for their relatively high prevalence of schizophrenia. Our previous population-genetic study showed Daghestan has an extremely high genetic diversity between the ethnic populations and a low genetic diversity within them. The isolates selected for this study include some with more than 200 and some with less than 100 generations of demographical history since their founding. Based on pedigrees of multiply-affected families, we found that among individuals with schizophrenia, the measure of consanguinity was significantly higher in the parents of those born in winter/spring compared to those born in summer/autumn. Furthermore, compared to summer/autumn born, winter/spring born individuals with schizophrenia had an earlier age-of-onset, and more prominent auditory hallucinations. Our results suggest that the offspring of consanguineous marriages, and thus those with reduced allelic heterogeneity, may be more susceptible to the environmental factor(s) underpinning the season-of-the effect in schizophrenia.


Parasitology ◽  
2020 ◽  
Vol 147 (13) ◽  
pp. 1532-1537 ◽  
Author(s):  
Juan C. Garcia-R ◽  
Murray P. Cox ◽  
David T. S. Hayman

AbstractParasites sometimes expand their host range and cause new disease aetiologies. Genetic changes can then occur due to host-specific adaptive alterations, particularly when parasites cross between evolutionarily distant hosts. Characterizing genetic variation in Cryptosporidium from humans and other animals may have important implications for understanding disease dynamics and transmission. We analyse sequences from four loci (gp60, HSP-70, COWP and actin) representing multiple Cryptosporidium species reported in humans. We predicted low genetic diversity in species that present unusual human infections due to founder events and bottlenecks. High genetic diversity was observed in isolates from humans of Cryptosporidium meleagridis, Cryptosporidium cuniculus, Cryptosporidium hominis and Cryptosporidium parvum. A deviation of expected values of neutrality using Tajima's D was observed in C. cuniculus and C. meleagridis. The high genetic diversity in C. meleagridis and C. cuniculus did not match our expectations but deviations from neutrality indicate a recent decrease in genetic variability through a population bottleneck after an expansion event. Cryptosporidium hominis was also found with a significant Tajima's D positive value likely caused by recent population expansion of unusual genotypes in humans. These insights indicate that changes in genetic diversity can help us to understand host-parasite adaptation and evolution.


PLoS ONE ◽  
2019 ◽  
Vol 14 (4) ◽  
pp. e0215755
Author(s):  
Rokhaya Sane ◽  
Cheikh Talla ◽  
Babacar Diouf ◽  
Fatoumata Diene Sarr ◽  
Nafissatou Diagne ◽  
...  

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Taveesak Janetanakit ◽  
Supassama Chaiyawong ◽  
Kamonpan Charoenkul ◽  
Ratanaporn Tangwangvivat ◽  
Ekkapat Chamsai ◽  
...  

Abstract Background Enterovirus G (EV-G) causes subclinical infections and is occasionally associated with diarrhea in pigs. In this study, we conducted a cross-sectional survey of EV-G in pigs from 73 pig farms in 20 provinces of Thailand from December 2014 to January 2018. Results Our results showed a high occurrence of EV-Gs which 71.6 % of fecal and intestinal samples (556/777) and 71.2 % of pig farms (52/73) were positive for EV-G by RT-PCR specific to the 5’UTR. EV-Gs could be detected in all age pig groups, and the percentage positivity was highest in the fattening group (89.7 %), followed by the nursery group (89.4 %). To characterize the viruses, 34 EV-G representatives were characterized by VP1 gene sequencing. Pairwise sequence comparison and phylogenetic analysis showed that Thai-EV-Gs belonged to the EV-G1, EV-G3, EV-G4, EV-G8, EV-G9 and EV-G10 genotypes, among which the EV-G3 was the predominant genotype in Thailand. Co-infection with different EV-G genotypes or with EV-Gs and porcine epidemic diarrhea virus (PEDV) or porcine deltacoronavirus (PDCoV) on the same pig farms was observed. Conclusions Our results confirmed that EV-G infection is endemic in Thailand, with a high genetic diversity of different genotypes. This study constitutes the first report of the genetic characterization of EV-GS in pigs in Thailand.


2021 ◽  
Author(s):  
Muzafar Shah ◽  
Ibrar Ullah ◽  
Sahib Gul Afridi ◽  
Muhammad Israr ◽  
Asifullah Khan ◽  
...  

Plasmodium falciparum, the main causative agent of malaria is an important public health vector in Khyber Pakhtunkhwa, Pakistan. Identification of the genetic diversity of malaria parasites can inform the intensity of transmission and identify potential deficiencies in malaria control programs. The aim of this study was to investigate the genetic diversity, allele frequencies and multiplicity of infection (MOI) of P. falciparum in Khyber Pakhtunkhwa, Pakistan. Methods: A total of 85 isolates from patients presenting to the local health centers with P. falciparum species were collected from 2017 to 2019. Parasite DNA was extracted from a total of 200 micro litter whole blood per patient using the Qiagen DNA extraction kit according to manufactures instructions. The polymorphic region of msp-1, msp-2 and glurp loci were genotyped by using nested polymerase chain reactions followed by gel electrophoresis for fragment analysis. Results: Genetic diversity and allelic frequencies of msp-1, msp-2 and glurp were identified in 85 blood samples. A total of 62 msp alleles were detected in which 30 for msp-1 and 32 for msp-2. For msp-1 the successful amplification occurred in (75/85) 88.23% isolates for msp-1, 78.9% (67/85) for msp-2 and 70% (60/85) for glurp. For msp-1, the K1 allelic family was predominant at 66.66% (50/75), followed by RO33 and MAD20. The frequency of samples having only K1, MAD20 and RO33 were 21.34% (16/75), 8% (6/75) and 10.67% (8/75) respectively. In msp-2, the FC27 allelic family was the most abundant with 70.14% (47/67) compared to 3D7 with 67.16% (45/67). Nine glurp RII region genotypes were identified. The overall mean multiplicity of infection was 2.6 with1.8 and 1.4 for msp-1 and msp-2 respectively while for glurp RII genes (MOI=1.03). There was no significant association between multiplicity of infection and age group (Spearman rank coefficient = 0.050; P = 0.6). There was significant correlation between MOI and parasite density for msp-2 allelic family. Conclusion: Our study showed high genetic diversity and allelic frequency with multiple clones of msp-1, msp-2 and glurp in P. falciparum isolates from malaria patients in Khyber Pakhtunkhwa Pakistan. In the present study the genotype data provided the valuable information which is essential for monitoring the impact of malaria eradication efforts in this region.


2019 ◽  
Vol 4 (Suppl 3) ◽  
pp. A40.1-A40
Author(s):  
Dossou Akpéyédjé ◽  
Saadou Issifou

BackgroundIn sub-Saharan Africa, malaria during pregnancy is a major health problem because it poses significant risks for the pregnant woman and the foetus. The sequestration of Plasmodium falciparum-infected erythrocytes in the placenta has consequences for the mother and the foetus. This study aimed to evaluate the allelic polymorphism of the Plasmodium falciparum MSP-2 gene related to the consequences of placental malaria.MethodsIt was a cross-sectional study conducted over two periods lasting six months in 2016 and 2017. The maternity center of the Hospital of Borgou-Alibori in Benin served as a framework for the study. From the 98 parturients included, placental blood samples were taken and then genotyped.ResultsUsing the MSP-2 gene as marker, the prevalence was 17, 34%. The MSP-2 gene was polymorphic with 9 distinct allelic types for both 3D7 and FC27 families (150 bp; 200 bp; 250 bp; 275 bp; 300 bp; 350 bp; 400 bp; 450 bp and 500 bp). The FC27 allelic family was predominant over the 3D7 family with 56, 25% and 43, 75% respectively. The 300 bp allelic type (50%) was predominant in the FC27 family while the 400 bp type was predominant in 3D7 family (35, 71%). 9 women had polyclonality (52,94%). The multiplicity of infection (MOI) was 1, 88. The number of strains ranged 1 to 4 in infected women. In univariate analysis there was no significant relationship between MSP-2 gene polymorphism and maternofoetal consequences. The absence of „prenatal consultation (p=0.0270), non-taking of IPTp/SP (p=0.0060), the occurrence of malaria in the third trimester (p=0,0364) and moderate maternal anaemia (p=0.0277) were associated with the polymorphism of MSP-2 gene. The MOI was significantly associated with parasite density of infected women.ConclusionPlasmodium falciparum MSP-2 gene was polymorphic in infected women at Parakou. Several factors related to pregnancy monitoring were associated with this genetic diversity. It is therefore essential to ensure correct follow-up of pregnancies.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Jiahai Wang ◽  
Ning Wang ◽  
Dandan Hu ◽  
Xiuqin Zhong ◽  
Shuxian Wang ◽  
...  

We evaluated genetic diversity and structure ofEchinococcus granulosusby analyzing the complete mitochondrial NADH dehydrogenase subunit 2 (ND2) gene in 51 isolates ofE. granulosus sensu strictometacestodes collected at three locations in this region. We detected 19 haplotypes, which formed a distinct clade with the standard sheep strain (G1). Hence, all 51 isolates were identified asE. granulosus sensu stricto(G1–G3). Genetic relationships among haplotypes were not associated with geographical divisions, and fixation indices (Fst) among sampling localities were low. Hence, regional populations ofE. granulosusin the southwest China are not differentiated, as gene flow among them remains high. This information is important for formulating unified region-wide prevention and control measures. We found large negative Fu’s Fs and Tajima’sDvalues and a unimodal mismatch distribution, indicating that the population has undergone a demographic expansion. We observed high genetic diversity among theE. granulosus s. s.isolates, indicating that the parasite population in this important bioregion is genetically robust and likely to survive and spread. The data from this study will prove valuable for future studies focusing on improving diagnosis and prevention methods and developing robust control strategies.


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