scholarly journals Gene flow and cross-mating in Plasmodium falciparum in households in a Tanzanian village

Parasitology ◽  
1995 ◽  
Vol 111 (4) ◽  
pp. 433-442 ◽  
Author(s):  
H. A. Babiker ◽  
J. D. Charlwood ◽  
T. Smith ◽  
D. Walliker
Keyword(s):  
Plasmodium Falciparum ◽  
Gene Flow ◽  
Spatial Clustering ◽  
Natural Populations ◽  
Surface Proteins ◽  
Chain Reaction ◽  
Allelic Variants ◽  
Genes Encoding ◽  
Capture Recapture ◽  
Polymerase Chain

SUMMARYThe diversity of the genes encoding 2 merozoite surface proteins (MSP-1 and MSP-2) of Plasmodium falciparum has been examined in parasites infecting members of 4 households in a village in Tanzania. The polymerase chain reaction (PCR) was used to characterize allelic variants of these genes by the sizes and sequences of regions of tandemly repeated bases in each gene. In each household extensive polymorphism was detected among parasites in the inhabitants and in infected mosquitoes caught in their houses. Similar frequencies of the alleles of these genes were observed in all households. Capture-recapture data indicated that both Anopheles gambiae and A.funestus freely dispersed among households in the hamlet. The results confirm that cross-mating and gene flow occur extensively among the parasites, and are discussed within the context of spatial clustering of natural populations of P. falciparum.

scholarly journals The Yeast Signal Sequence Trap Identifies Secreted Proteins of the Hemibiotrophic Corn Pathogen Colletotrichum graminicola

2008 ◽  
Vol 21 (10) ◽  
pp. 1325-1336 ◽  
Author(s):  
Jorrit-Jan Krijger ◽  
Ralf Horbach ◽  
Michael Behr ◽  
Patrick Schweizer ◽  
Holger B. Deising ◽  
...  
Keyword(s):  
Cell Walls ◽  
Leaf Extract ◽  
Signal Sequence ◽  
Stem Rot ◽  
Colletotrichum Graminicola ◽  
In Planta ◽  
Chain Reaction ◽  
Genes Encoding ◽  
Polymerase Chain

The hemibiotroph Colletotrichum graminicola is the causal agent of stem rot and leaf anthracnose on Zea mays. Following penetration of epidermal cells, the fungus enters a short biotrophic phase, followed by a destructive necrotrophic phase of pathogenesis. During both phases, secreted fungal proteins are supposed to determine progress and success of the infection. To identify genes encoding such proteins, we constructed a yeast signal sequence trap (YSST) cDNA-library from RNA extracted from mycelium grown in vitro on corn cell walls and leaf extract. Of the 103 identified unigenes, 50 showed significant similarities to genes with a reported function, 25 sequences were similar to genes without a known function, and 28 sequences showed no similarity to entries in the databases. Macroarray hybridization and quantitative reverse-transcriptase polymerase chain reaction confirmed that most genes identified by the YSST screen are expressed in planta. Other than some genes that were constantly expressed, a larger set showed peaks of transcript abundances at specific phases of pathogenesis. Another set exhibited biphasic expression with peaks at the biotrophic and necrotrophic phase. Transcript analyses of in vitro-grown cultures revealed that several of the genes identified by the YSST screen were induced by the addition of corn leaf components, indicating that host-derived factors may have mimicked the host milieu.

scholarly journals Missed Plasmodium falciparum and Plasmodium vivax Mixed Infections in Ethiopia Threaten Malaria Elimination

2021 ◽  
Author(s):  
Colleen M. Leonard ◽  
Hussein Mohammed ◽  
Mekonnen Tadesse ◽  
Jessica N. McCaffery ◽  
Doug Nace ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Plasmodium Falciparum ◽  
Lactate Dehydrogenase ◽  
Plasmodium Vivax ◽  
Therapeutic Efficacy ◽  
Dried Blood Spots ◽  
Mixed Infections ◽  
Efficacy Study ◽  
Chain Reaction ◽  
Polymerase Chain

Plasmodium falciparum and Plasmodium vivax are co-endemic in Ethiopia. This study investigated whether mixed infections were missed by microscopy from a 2017 therapeutic efficacy study at two health facilities in Ethiopia. All patients (N = 304) were initially classified as having single-species P. falciparum (n = 148 samples) or P. vivax infections (n = 156). Dried blood spots were tested for Plasmodium antigens by bead-based multiplex assay for pan-Plasmodium aldolase, pan-Plasmodium lactate dehydrogenase, P. vivax lactate dehydrogenase, and histidine-rich protein 2. Of 304 blood samples, 13 (4.3%) contained both P. falciparum and P. vivax antigens and were analyzed by polymerase chain reaction for species-specific DNA. Of these 13 samples, five were confirmed by polymerase chain reaction for P. falciparum/P. vivax co-infection. One sample, initially classified as P. vivax by microscopy, was found to only have Plasmodium ovale DNA. Plasmodium falciparum/P. vivax mixed infections can be missed by microscopy even in the context of a therapeutic efficacy study with multiple trained readers.

Genes coding for LysM domains in the dermatophyte Trichophyton rubrum: A transcription analysis

2019 ◽  
Vol 58 (3) ◽  
pp. 372-379 ◽  
Author(s):  
Lúcia Lopes ◽  
Tamires A Bitencourt ◽  
Elza A S Lang ◽  
Pablo R Sanches ◽  
Nalu T A Peres ◽  
...  
Keyword(s):  
Catalytic Domain ◽  
Trichophyton Rubrum ◽  
Carbohydrate Binding ◽  
Biological Functions ◽  
Chain Reaction ◽  
Transcription Analysis ◽  
Lysm Domain ◽  
Genes Encoding ◽  
Polymerase Chain ◽  
In Silico Analyses

Abstract The filamentous fungus Trichophyton rubrum is a pathogen that causes superficial mycoses in humans, predominantly in keratinized tissues. The occurrence of dermatophytoses has increased in the last decades, mainly in immunocompromised patients, warranting research on the mechanisms involved in dermatophyte virulence. The genomes of dermatophytes are known to be enriched in genes coding for proteins containing the LysM domain, a carbohydrate-binding module, indicating the possible involvement of these genes in virulence. Although the LysM domains have already been described in other fungi, their biological functions in dermatophytes are unknown. Here we assessed the transcription of genes encoding proteins containing the LysM domains in T. rubrum grown on different substrates using quantitative real-time polymerase chain reaction. Some of these genes showed changes in transcription levels when T. rubrum was grown on keratin. In silico analyses suggest that some of these proteins share features, namely, they are anchored in the plasma membrane and contain the catalytic domain chitinase II and signal peptide domains. Here we show a detailed study of genes encoding the proteins with LysM-containing domains in T. rubrum, aiming to contribute to the understanding of their functions in dermatophytes.

HRP2/3 mutation in recrudescent Plasmodium falciparum malaria case acquired in Ethiopia

2020 ◽  
Author(s):  
Shiraz Gefen-Halevi ◽  
Valentin Belinson ◽  
Uri Manor ◽  
Zeala Gazit ◽  
Gill Smollan ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Plasmodium Falciparum ◽  
Lactate Dehydrogenase ◽  
Falciparum Malaria ◽  
Malaria Case ◽  
Rapid Detection ◽  
Plasmodium Falciparum Malaria ◽  
Malaria Prophylaxis ◽  
Chain Reaction ◽  
Polymerase Chain

A 65-year-old Israeli working in Welkait, Ethiopia, not using malaria prophylaxis, developed fever. Malaria rapid detection test was consistent with non-falciparum malaria (plasmodium lactate dehydrogenase+/histidine-rich protein− [LDH+/HRP−]) but microscopy showed typical Plasmodium falciparum. HRP2/3 were negative by polymerase chain reaction. The patient suffered two recrudescence episodes following artemether–lumefantrine and atovaquone–proguanil treatments, and responded to mefloquine treatment.

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