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  1. Article ; Online: Estimation of parasite age and synchrony status in Plasmodium falciparum infections

    Laura Ciuffreda / Felix Kwame Zoiku / Neils B. Quashie / Lisa C. Ranford-Cartwright

    Scientific Reports, Vol 10, Iss 1, Pp 1-

    2020  Volume 10

    Abstract: Abstract Human malaria parasites have complex but poorly understood population dynamics inside their human host. In some but not all infections, parasites progress synchronously through the 48 h lifecycle following erythrocyte invasion, such that at any ... ...

    Abstract Abstract Human malaria parasites have complex but poorly understood population dynamics inside their human host. In some but not all infections, parasites progress synchronously through the 48 h lifecycle following erythrocyte invasion, such that at any one time there is a limited spread of parasites at a particular time (hours) post-invasion. Patients presenting with older parasites, and with asynchronous infections, have been reported to have higher risks of fatal outcomes, associated with higher parasite biomass and multiplication rates respectively. However, practical tools to assess synchrony and estimate parasite age post-invasion in patient samples are lacking. We have developed a novel method based on three genes differentially expressed over the parasite intra-erythrocytic lifecycle, and applied it to samples from patients with uncomplicated malaria attending two health clinics in Ghana. We found that most patients presented with synchronous infections, and with parasites within 12 h of erythrocyte invasion. Finally we investigated if clinical features such as fever and parasite density could act as predictors of parasite age and synchrony. The new method is a simple and practicable approach to study parasite dynamics in naturally-infected patients, and is a significant improvement on the subjective microscopical methods for parasite staging in vivo, aiding patient management.
    Keywords Medicine ; R ; Science ; Q
    Subject code 572 ; 616
    Language English
    Publishing date 2020-07-01T00:00:00Z
    Publisher Nature Publishing Group
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article ; Online: The impact of storage conditions on human stool 16S rRNA microbiome composition and diversity

    Lauren V. Carruthers / Arinaitwe Moses / Moses Adriko / Christina L. Faust / Edridah M. Tukahebwa / Lindsay J. Hall / Lisa C. Ranford-Cartwright / Poppy H.L. Lamberton

    PeerJ, Vol 7, p e

    2019  Volume 8133

    Abstract: Background Multiple factors can influence stool sample integrity upon sample collection. Preservation of faecal samples for microbiome studies is therefore an important step, particularly in tropical regions where resources are limited and high ... ...

    Abstract Background Multiple factors can influence stool sample integrity upon sample collection. Preservation of faecal samples for microbiome studies is therefore an important step, particularly in tropical regions where resources are limited and high temperatures may significantly influence microbiota profiles. Freezing is the accepted standard to preserve faecal samples however, cold chain methods are often unfeasible in fieldwork scenarios particularly in low and middle-income countries and alternatives are required. This study therefore aimed to address the impact of different preservative methods, time-to-freezing at ambient tropical temperatures, and stool heterogeneity on stool microbiome diversity and composition under real-life physical environments found in resource-limited fieldwork conditions. Methods Inner and outer stool samples collected from one specimen obtained from three children were stored using different storage preservation methods (raw, ethanol and RNAlater) in a Ugandan field setting. Mixed stool was also stored using these techniques and frozen at different time-to-freezing intervals post-collection from 0–32 h. Metataxonomic profiling was used to profile samples, targeting the V1–V2 regions of 16S rRNA with samples run on a MiSeq platform. Reads were trimmed, combined and aligned to the Greengenes database. Microbial diversity and composition data were generated and analysed using Quantitative Insights Into Microbial Ecology and R software. Results Child donor was the greatest predictor of microbiome variation between the stool samples, with all samples remaining identifiable to their child of origin despite the stool being stored under a variety of conditions. However, significant differences were observed in composition and diversity between preservation techniques, but intra-preservation technique variation was minimal for all preservation methods, and across the time-to-freezing range (0–32 h) used. Stool heterogeneity yielded no apparent microbiome differences. Conclusions Stool ...
    Keywords Microbiome ; Stool ; Storage conditions ; 16S rRNA ; Bacteria ; Microbiota ; Medicine ; R ; Biology (General) ; QH301-705.5
    Subject code 500
    Language English
    Publishing date 2019-12-01T00:00:00Z
    Publisher PeerJ Inc.
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  3. Article ; Online: Characterisation of Species and Diversity of Anopheles gambiae Keele Colony.

    Lisa C Ranford-Cartwright / Sion McGeechan / Donald Inch / Graeme Smart / Lenka Richterová / Jonathan M Mwangi

    PLoS ONE, Vol 11, Iss 12, p e

    2016  Volume 0168999

    Abstract: Anopheles gambiae sensu stricto was recently reclassified as two species, An. coluzzii and An. gambiae s.s., in wild-caught mosquitoes, on the basis of the molecular form, denoted M or S, of a marker on the X chromosome. The An. gambiae Keele line is an ... ...

    Abstract Anopheles gambiae sensu stricto was recently reclassified as two species, An. coluzzii and An. gambiae s.s., in wild-caught mosquitoes, on the basis of the molecular form, denoted M or S, of a marker on the X chromosome. The An. gambiae Keele line is an outbred laboratory colony strain that was developed around 12 years ago by crosses between mosquitoes from 4 existing An. gambiae colonies. Laboratory colonies of mosquitoes often have limited genetic diversity because of small starting populations (founder effect) and subsequent fluctuations in colony size. Here we describe the characterisation of the chromosomal form(s) present in the Keele line, and investigate the diversity present in the colony using microsatellite markers on chromosome 3. We also characterise the large 2La inversion on chromosome 2. The results indicate that only the M-form of the chromosome X marker is present in the Keele colony, which was unexpected given that 3 of the 4 parent colonies were probably S-form. Levels of diversity were relatively high, as indicated by a mean number of microsatellite alleles of 6.25 across 4 microsatellites, in at least 25 mosquitoes. Both karyotypes of the inversion on chromosome 2 (2La/2L+a) were found to be present at approximately equal proportions. The Keele colony has a mixed M- and S-form origin, and in common with the PEST strain, we propose continuing to denote it as an An. gambiae s.s. line.
    Keywords Medicine ; R ; Science ; Q
    Subject code 590
    Language English
    Publishing date 2016-01-01T00:00:00Z
    Publisher Public Library of Science (PLoS)
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  4. Article ; Online: Associations between Season and Gametocyte Dynamics in Chronic Plasmodium falciparum Infections.

    Amal A H Gadalla / Petra Schneider / Thomas S Churcher / Elkhansaa Nassir / Abdel-Muhsin A Abdel-Muhsin / Lisa C Ranford-Cartwright / Sarah E Reece / Hamza A Babiker

    PLoS ONE, Vol 11, Iss 11, p e

    2016  Volume 0166699

    Abstract: INTRODUCTION:In a markedly seasonal malaria setting, the transition from the transmission-free dry season to the transmission season depends on the resurgence of the mosquito population following the start of annual rains. The sudden onset of malaria ... ...

    Abstract INTRODUCTION:In a markedly seasonal malaria setting, the transition from the transmission-free dry season to the transmission season depends on the resurgence of the mosquito population following the start of annual rains. The sudden onset of malaria outbreaks at the start of the transmission season suggests that parasites persist during the dry season and respond to either the reappearance of vectors, or correlated events, by increasing the production of transmission stages. Here, we investigate whether Plasmodium falciparum gametocyte density and the correlation between gametocyte density and parasite density show seasonal variation in chronic (largely asymptomatic) carriers in eastern Sudan. MATERIALS AND METHODS:We recruited and treated 123 malaria patients in the transmission season 2001. We then followed them monthly during four distinct consecutive epidemiological seasons: transmission season 1, transmission-free season, pre-clinical period, and transmission season 2. In samples collected from 25 participants who fulfilled the selection criteria of the current analysis, we used quantitative PCR (qPCR) and RT-qPCR to quantify parasite and gametocyte densities, respectively. RESULTS AND DISCUSSION:We observed a significant increase in gametocyte density and a significantly steeper positive correlation between gametocyte density and total parasite density during the pre-clinical period compared to the preceding transmission-free season. However, there was no corresponding increase in the density or prevalence of total parasites or gametocyte prevalence. The increase in gametocyte production during the pre-clinical period supports the hypothesis that P. falciparum may respond to environmental cues, such as mosquito biting, to modulate its transmission strategy. Thus, seasonal changes may be important to ignite transmission in unstable-malaria settings.
    Keywords Medicine ; R ; Science ; Q
    Subject code 333
    Language English
    Publishing date 2016-01-01T00:00:00Z
    Publisher Public Library of Science (PLoS)
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  5. Article: A comprehensive transcriptomic view of renal function in the malaria vector, Anopheles gambiae

    Overend, Gayle / Pablo Cabrero / Kenneth A. Halberg / Lisa C. Ranford-Cartwright / Debra J. Woods / Shireen A. Davies / Julian A.T. Dow

    Insect biochemistry and molecular biology. 2015 Dec., v. 67

    2015  

    Abstract: Renal function is essential to maintain homeostasis. This is particularly significant for insects that undergo complete metamorphosis; larval mosquitoes must survive a freshwater habitat whereas adults are terrestrial, and mature females must maintain ... ...

    Abstract Renal function is essential to maintain homeostasis. This is particularly significant for insects that undergo complete metamorphosis; larval mosquitoes must survive a freshwater habitat whereas adults are terrestrial, and mature females must maintain ion and fluid homeostasis after blood feeding. To investigate the physiological adaptations required for successful development to adulthood, we studied the Malpighian tubule transcriptome of Anopheles gambiae using Affymetrix arrays. We assessed transcription under several conditions; as third instar larvae, as adult males fed on sugar, as adult females fed on sugar, and adult females after a blood meal. In addition to providing the most detailed transcriptomic data to date on the Anopheles Malpighian tubules, the data provide unique information on the renal adaptations required for the switch from freshwater to terrestrial habitats, on gender differences, and on the contrast between nectar-feeding and haematophagy. We found clear differences associated with ontogenetic change in lifestyle, gender and diet, particularly in the neuropeptide receptors that control fluid secretion, and the water and ion transporters that impact volume and composition. These data were also combined with transcriptomics from the Drosophila melanogaster tubule, allowing meta-analysis of the genes which underpin tubule function across Diptera. To further investigate renal conservation across species we selected four D. melanogaster genes with orthologues highly enriched in the Anopheles tubules, and generated RNAi knockdown flies. Three of these genes proved essential, showing conservation of critical functions across 150 million years of phylogenetic separation. This extensive data-set is available as an online resource, MozTubules.org, and could potentially be mined for novel insecticide targets that can impact this critical organ in this pest species.
    Keywords Anopheles gambiae ; Drosophila melanogaster ; Malpighian tubules ; RNA interference ; adulthood ; adults ; data collection ; diet ; females ; freshwater ; gender differences ; genes ; habitats ; hematophagy ; homeostasis ; insect vectors ; insecticides ; instars ; larvae ; lifestyle ; males ; meta-analysis ; metamorphosis ; nectar feeding ; neuropeptide receptors ; ontogeny ; pests ; phylogeny ; renal function ; secretion ; sugars ; transcription (genetics) ; transcriptome ; transcriptomics ; transporters
    Language English
    Dates of publication 2015-12
    Size p. 47-58.
    Publishing place Elsevier Ltd
    Document type Article
    ZDB-ID 1483248-3
    ISSN 1879-0240 ; 0965-1748
    ISSN (online) 1879-0240
    ISSN 0965-1748
    DOI 10.1016/j.ibmb.2015.05.007
    Database NAL-Catalogue (AGRICOLA)

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