Genetic diversity in merozoite surface protein 1 of Plasmodium falciparum isolates from Igbogbo-bayeku, Lagos, Nigeria

Mutations in merozoite surface protein 1 (MSP1) serve as indicators of genetic diversity in Plasmodium falciparum population in a given area. Diversity in MSP1 gene of P. falciparum isolates in Igbogbo-Bayeku, a periurban settlement of Lagos, Nigeria was assessed. Malaria was diagnosed by microscopy and polymerase chain reaction (PCR). MSP1 gene polymorphisms were analyzed in P. falciparum-positive samples using allele-specific primers of the three families of MSP1 block 2. Of the 63 malaria cases, 34 (54%) were microscopic while 29 (46%) were sub-microscopic cases. The three MSP1 families were present in the P. falciparum isolates with RO33 being the most abundant (55; 87.3%). Thirteen distinct genotypes of MSP1 were observed. There were more polyclonal infections (40; 63.5%) than monoclonal infections (23; 36.5%). The multiplicity of infection (MOI) was 1.98 and the expected heterozygosity (He) was 0.64. Participants aged >8 years had significantly higher MOI (2.26±0.98) than those aged £ 8 years (1.78±0.83) (P=0.04). Polyclonal infections were similar in microscopic (23/39; 67.6%) and sub-microscopic infections (17/29; 58.6%) (P=0.46). However, polyinfections were more in microscopic (26/34; 76.5%) than in submicroscopic infections (15/29; 51.7%) (P=0.04). A high level of genetic diversity was observed in the P. falciparum isolates in this community-based study which is an indication of intense malaria transmission.&nbsp

IN-VIVO ANTI-PLASMODIAL ACTIVITY AND IN-VITRO ANTIOXIDANT PROPERTIES OF METHANOLIC LEAF EXTRACT OF AZADIRACHTA INDICA AND ITS POSITIVE EFFECT ON HEMATOLOGICAL AND LIPID PARAMETERS IN SWISS ALBINO MICE INFECTED WITH PLASMODIUM BERGHEI NK 65.

The study was conducted to determine the effect of in vivo anti-plasmodial and in vitro antioxidant properties of methanolic leaf extract of Azadirachta indica and its positive effect on hematological and lipid parameters in Swiss albino mice infected with Plasmodium berghei NK65. Swiss albino mice were inoculated intraperitoneally with Plasmodium berghei NK65. The mice were grouped into six groups, five per group. Group I were not infected with P.berghei, Group II and III served as both the negative and positive control while Group IV, V, and VI were treated with 200, 400, and 800 mg/kg body weight of methanolic leaf extract of A. indica. The secondary metabolites in the extract include tannin, flavonoids, glycosides and saponin etc. The extract does not have any toxic effect that can lead to the death of the animals. The median lethal dose LD50 was estimated to be >5000mg/Kg body weight. The extract caused 47.80%, 50.96% and 52.30% suppression in parasitaemia at 200, 400 and 800mg/kg body weight respectively while Chloroquine exerted 100% suppression at 5mg/kg body weight. The curative test shows that the different concentration of the extract exert a growth inhibition of 50.1%, 74.57% and 73.68% at 200, 400, 800mg/kg body weight respectively while Chloroquine cleared the parasites by 94.07% at 5mg/kg body weight. The Hematological parameters showed that the extract is not hematotoxic since it significantly increase (P<0.05) RBC, HGB, and HCT values while their WBC count reduced significantly when compared to the infected untreated mice. There is a significant decrease (P<0.05) in plasma TC, TG and LDL-C in the treated groups and their HDL-C significantly increase when compared to infected untreated group. This study shows that A.indica extract has hypolipidemic effect. In the in-vitro antioxidant assay, the extract significantly increase (P<0.05) the level of SOD, CAT and GSH in the liver homogenate induced with oxidative stress using H2O2 while the MDA values reduced significantly with the administration of the extract of A.indica

IN-VIVO ANTI-PLASMODIAL ACTIVITY AND IN-VITRO ANTIOXIDANT PROPERTIES OF METHANOLIC LEAF EXTRACT OF AZADIRACHTA INDICA AND ITS POSITIVE EFFECT ON HEMATOLOGICAL AND LIPID PARAMETERS IN SWISS ALBINO MICE INFECTED WITH PLASMODIUM BERGHEI NK 65.

The study was conducted to determine the effect of in vivo anti-plasmodial and in vitro antioxidant properties of methanolic leaf extract of Azadirachta indica and its positive effect on hematological and lipid parameters in Swiss albino mice infected with Plasmodium berghei NK65. Swiss albino mice were inoculated intraperitoneally with Plasmodium berghei NK65. The mice were grouped into six groups, five per group. Group I were not infected with P.berghei, Group II and III served as both the negative and positive control while Group IV, V, and VI were treated with 200, 400, and 800 mg/kg body weight of methanolic leaf extract of A. indica. The secondary metabolites in the extract include tannin, flavonoids, glycosides and saponin etc. The extract does not have any toxic effect that can lead to the death of the animals. The median lethal dose LD50 was estimated to be >5000mg/Kg body weight. The extract caused 47.80%, 50.96% and 52.30% suppression in parasitaemia at 200, 400 and 800mg/kg body weight respectively while Chloroquine exerted 100% suppression at 5mg/kg body weight. The curative test shows that the different concentration of the extract exert a growth inhibition of 50.1%, 74.57% and 73.68% at 200, 400, 800mg/kg body weight respectively while Chloroquine cleared the parasites by 94.07% at 5mg/kg body weight. The Hematological parameters showed that the extract is not hematotoxic since it significantly increase (P<0.05) RBC, HGB, and HCT values while their WBC count reduced significantly when compared to the infected untreated mice. There is a significant decrease (P<0.05) in plasma TC, TG and LDL-C in the treated groups and their HDL-C significantly increase when compared to infected untreated group. This study shows that A.indica extract has hypolipidemic effect. In the in-vitro antioxidant assay, the extract significantly increase (P<0.05) the level of SOD, CAT and GSH in the liver homogenate induced with oxidative stress using H2O2 while the MDA values reduced significantly with the administration of the extract of A.indica

High cases of submicroscopic Plasmodium falciparum infections in a suburban population of Lagos, Nigeria.

BACKGROUND: Asymptomatic malaria parasites are significant sources of infections for onward malaria transmission. Conventional tools for malaria diagnosis such as microscopy and rapid diagnostic test kits (RDT) have relatively low sensitivity, hence the need for alternative tools for active screening of such low-density infections. METHODS: This study tested var acidic terminal sequence-based (varATS) quantitative polymerase chain reaction (qPCR) for screening asymptomatic Plasmodium falciparum infections among dwellers of a sub-urban community in Lagos, Nigeria. Clinically healthy participants were screened for malaria using microscopy, RDT and varATS qPCR techniques. Participants were stratified into three age groups: 1-5, 6-14 and > 14 years old. RESULTS: Of the 316 participants screened for asymptomatic malaria infection, 78 (24.68%) were positive by microscopy, 99 (31.33%) were positive by RDT and 112 (35.44%) by varATS qPCR. Participants aged 6-14 years had the highest prevalence of asymptomatic malaria, with geometric means of ~ 116 parasites/µL and ~ 6689 parasites/µL as detected by microscopy and varATS, respectively. CONCLUSION: This study has revealed high prevalence of asymptomatic malaria in the study population, with varATS detecting additional sub-microscopic infections. The highest concentration of asymptomatic malaria was observed among school-age children between 6 and 14 years old. A large-scale screening to identify other potential hotspots of asymptomatic parasites in the country is recommended

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

In Vivo Anti-Plasmodial Activity and the Effect of Ethanolic Leaf Extract of Rauvolfia Vomitoria on Hematological and Lipid Parameters in Swiss Mice Infected with Plasmodium Berghei NK 65

Rauvolfia vomitoria is a medicinal plant used locally in Nigeria for the management of malaria and other ailments. The study was conducted to determine the effect of ethanolic leaf extract of R. vomitoria on  hematological and lipid parameters in mice infected with Plasmodium berghei NK65. Swiss mice were inoculated intraperitoneally with P.berghei NK65. The mice were grouped into six groups, of five per group. Only Group A were not infected with P.berghei, Groups B and C served as both positive and negative control while Groups D, E, and F were treated with 200, 400, and 800 mg/kg body weight of R. vomitoria extract. The phytochemical constituents of the extract showed the presence of secondary metabolites like tannin, flavonoids, steroids and saponin. The extract of R.vomitoria showed marked anti-malaria effects in dose seeming fashion from the percentage parasitaemia computed after carrying out suppressive and curative test. The hematological parameters showed that R. vomitoria had a significant increase in HCT, RBC, HGB, and platelet values when compared to negative control. There was a significant increase in plasma TC, TG, VLDL, HDL-C and LDL-C in the infected untreated group compared to other groups. This study showed that R. vomitoria extract suppressed the growth of P. berghei NK65 and it had antihyperglycemic and hypolipidemic effect on animals infected with P. berghei NK65.Keywords: Rauvolfia vomitoria, Anti-plasmodial, Swiss albino mice, Plasmodium berghei NK 65 and Biochemical parameters

Optimization of the Protein Nutritive Value of Wheat/Cassava Breadmix by Supplementing with Limiting Amino-Acids (L-Lysine & L-Methionine)

This study was carried out in line with the National policy on bread to incorporate 10% cassava flour into wheat flour for all bread baked in Nigeria. The objective of this study was to investigate if the addition of 10% cassava flour or more could be accommodated without compromising the nutritive value of bread. The effect of fortifying with limiting amino-acids was also investigated. This study employed a feeding trial and bioassay of tissues from albino rats of Wistar strain, to evaluate the effect of supplementing various levels of wheat/cassava bread mix feed, with 0.1% L-lysine and 0.1% L-methionine. Nine different diet regimens were used with four rats in each diet group. Cassava (100%) diet group was used as the control; and the diets fortified with 0.1% L-lysine and 0.1% Lmethionine used as secondary control. The parameters measured as 'markers' of nutritive value included: body weight changes, food conversion ratio (FCR) and net protein utilisation (NPU). The effects of dietary intake of the various wheat/cassava supplemented diets on haematological indices such as mean corpuscular haemoglobin concentration and biochemical indices such as cortisol, total protein and albumin in the plasma of fed rats were also determined. Results indicated that both 10% and 20% cassava input supported adequate nutritional and biochemical development of the fed rats, although fortification of the diets with 0.1% L-lysine and 0.1% L-methionine resulted in 10 – 20% improvement in all the nutritional indicators measured. Based on the results of this study, it was concluded that incorporation of 20% cassava flour into wheat bread supplemented with L-lysine and L-methionine is nutritionally better than, but haematologically and biochemically comparable to whole wheat bread in rats. Therefore, this findings lend support to the national policy on nutrient fortification and cassava incorporation into wheatbread for the general goal of improving food security in Nigeria.Keywords: Bread fortification, Weanling rat, L-methionine, L-Lysine, haematological indices, biochemical indicesNigerian Journal of Parasitology, Vol. 32 [2] September 2011, pp. 287-29

Pro-inflammatory Cytokine Response and Genetic Diversity in Merozoite Surface Protein 2 of Plasmodium falciparum Isolates from Nigeria

Background: Polymorphisms in Plasmodium falciparum merozoite surface protein-2 (msp-2) and associated parasite genetic diversity which varies between malaria-endemic regions remain a limitation in malaria vaccine development. Pro-inflammatory cytokines are important in immunity against malaria, understanding the influence of genetic diversity on cytokine response is important for effective vaccine design. Methods: P. falciparum isolates obtained from 300 Nigerians with uncomplicated falciparum malaria at Ijede General Hospital, Ijede (IJE), General Hospital Ajeromi, Ajeromi (AJE) and Saint Kizito Mission Hospital, Lekki, were genotyped by nested polymerase chain reaction of msp-2 block 3 while ELISA was used to determine the pro-inflammatory cytokine response to describe the genetic diversity of P. falciparum. Results: Eighteen alleles were observed for msp-2 loci. Of the 195 isolates, 61 (31.0%) had only FC27-type alleles, 38 (19.7%) had only 3D7-type alleles, and 49.3% had multiple parasite lines with both alleles. Band sizes were 275–625 bp for FC27 and 150–425 bp for 3D7. Four alleles were observed from LEK, 2 (375–425 bp) and 2 (275–325 bp) of FC27-and 3D7-types, respectively; 12 alleles from AJE, 9 (275–625 bp) and 3 (325–425 bp) of FC27-types and 3D7-types, respectively; while IJE had a total of 12 alleles, 9 (275–625 bp) and 3 (325–425 bp) of FC27-types and 3D7-types, respectively. Mean multiplicity of infection (MOI) was 1.54. Heterozygosity (HE) ranged from 0.77 to 0.87 and was highest for IJE (0.87). Cytokine response was higher among 0.05) but with neither parasite density nor infection type. Conclusion: P. falciparum genetic diversity is extensive in Nigeria, protection via pro-inflammatory cytokines have little or no interplay with infection multiplicity

Genetic diversity and complexity of Plasmodium falciparum infections in Lagos, Nigeria

Objective: To analyse the genetic diversity of Plasmodium falciparum (P. falciparum) using msp-1 and msp-2 as antigenic markers. Methods: Parasite DNA was extracted from 100 blood samples collected from P. falciparum-positive patients confirmed by microscopy, and followed by PCR-genotyping targeting the msp-1 (block2) and msp-2 (block 3) allelic families. Results: All the families of msp-1 (K1, MAD20 and R033) and msp-2 (FC27 and 3D7) locus were observed. Results revealed that K1 (60/100) was the most predominant genotype of msp-1 allelic family followed by the genotypes of MAD20 (50/100) and R033 (45/100). In the msp-2 locus, FC27 genotype (62/100) showed higher frequency than 3D7 genotype (55/100). The allelic families were detected either alone or in combination with other families. However, no R033/MAD20 combination was observed. Multiplicity of infection (MOI) with msp-1 was higher in the locality of Ikorodu (1.50) than in Lekki (1.39). However, MOI with msp-2 was lower in the locality of Ikorodu (1.14) than in Lekki (1.76). There was no significant difference in the mean MOI between the two study areas (P=0.427). Conclusions: The observation of limited diversity of malaria parasites may imply that the use of antigenic markers as genotyping tools for distinguishing recrudescence and re-infections with P. falciparum during drug trials is subjective