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1.
Biochim Biophys Acta. 2016 Sep;1860(9):1898-909. doi: 10.1016/j.bbagen.2016.05.033. Epub 2016 May 27.

A novel mosquito ubiquitin targets viral envelope protein for degradation and reduces virion production during dengue virus infection.

Author information

  • 1Department of Pathology, Microbiology & Immunology, University of South Carolina School of Medicine, Columbia, SC 29209, United States.
  • 2Foundational Sciences, Central Michigan University College of Medicine, Mount Pleasant, MI 48859, United States.
  • 3Department of Tropical Medicine, Tulane University School of Public Health, New Orleans, LA 70112, United States.
  • 4Biosecurity Research Institute, Kansas State University, Manhattan, KS 66506, United States; Diagnostic Medicine and Pathobiology, Kansas State University, Manhattan, KS 66506, United States.
  • 5Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, United States; Howard Hughes Medical Institute, Chevy Chase, MD 20815, United States.
  • 6Department of Pathology, Microbiology & Immunology, University of South Carolina School of Medicine, Columbia, SC 29209, United States. Electronic address: tonya.colpitts@uscmed.sc.edu.

Abstract

BACKGROUND:

Dengue virus (DENV) is a mosquito-borne flavivirus that causes significant human disease and mortality in the tropics and subtropics. By examining the effects of virus infection on gene expression, and interactions between virus and vector, new targets for prevention of infection and novel treatments may be identified in mosquitoes. We previously performed a microarray analysis of the Aedes aegypti transcriptome during infection with DENV and found that mosquito ubiquitin protein Ub3881 (AAEL003881) was specifically and highly down-regulated. Ubiquitin proteins have multiple functions in insects, including marking proteins for proteasomal degradation, regulating apoptosis and mediating innate immune signaling.

METHODS:

We used qRT-PCR to quantify gene expression and infection, and RNAi to reduce Ub3881 expression. Mosquitoes were infected with DENV through blood feeding. We transfected DENV protein expression constructs to examine the effect of Ub3881 on protein degradation. We used site-directed mutagenesis and transfection to determine what amino acids are involved in Ub3881-mediated protein degradation. Immunofluorescence, Co-immunoprecipitation and Western blotting were used to examine protein interactions and co-localization.

RESULTS:

The overexpression of Ub3881, but not related ubiquitin proteins, decreased DENV infection in mosquito cells and live Ae. aegypti. The Ub3881 protein was demonstrated to be involved in DENV envelope protein degradation and reduce the number of infectious virions released.

CONCLUSIONS:

We conclude that Ub3881 has several antiviral functions in the mosquito, including specific viral protein degradation.

GENERAL SIGNIFICANCE:

Our data highlights Ub3881 as a target for future DENV prevention strategies in the mosquito transmission vector.

Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

KEYWORDS:

Arbovirus; Dengue virus; Mosquito transmission; Protein degradation; Ubiquitin

PMID:
27241849
PMCID:
PMC4949077
[Available on 2017-09-01]
DOI:
10.1016/j.bbagen.2016.05.033
[PubMed - in process]
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2.
Methods Mol Biol. 2016;1435:1-13. doi: 10.1007/978-1-4939-3670-0_1.

A Brief Review of West Nile Virus Biology.

Author information

  • 1Department of Pathology, Microbiology and Immunology, School of Medicine, University of South Carolina, 6439 Garners Ferry Rd, Bldg 2, Room B4, Columbia, SC, 29209, USA.
  • 2Department of Pathology, Microbiology and Immunology, School of Medicine, University of South Carolina, 6439 Garners Ferry Rd, Bldg 2, Room B4, Columbia, SC, 29209, USA. tonya.colpitts@uscmed.sc.edu.

Abstract

West Nile virus (WNV) is an arbovirus with increased global incidence in the last decade. It is also a major cause of human encephalitis in the USA. WNV is an arthropod-transmitted virus that mainly affects birds but humans become infected as incidental dead-end hosts which can cause outbreaks in naïve populations. The main vectors of WNV are mosquitoes of the genus Culex, which preferentially feed on birds. As in many other arboviruses, the characteristics that allow Flaviviruses like WNV to replicate and transmit to different hosts are encrypted in their genome, which also contains information for the production of structural and nonstructural proteins needed for host cell infection. WNV and other Flaviviruses have developed different strategies to establish infection, replication, and successful transmission. Most of these strategies include the diversion of the host's immune responses away from the virus. In this review, we describe the molecular structure and protein function of WNV with emphasis on protein involvement in the modulation of antiviral immune responses.

KEYWORDS:

Flavivirus; Virus immune evasion; WNV protein; WNV structure; West Nile virus

[PubMed - in process]
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3.
Biomedica. 2015 Oct-Dec;35(4):572-81. doi: 10.7705/biomedica.v35i4.2530.

Aedes aegypti anti-salivary gland antibody concentration and dengue virus exposure history in healthy individuals living in an endemic area in Colombia.

Author information

  • 1Grupo de Investigaciones en Enfermedades Parasitarias e Infecciosas, Universidad de Pamplona, Norte de Santander, Colombia.
  • 2Hospital Local Los Patios, Norte de Santander, Colombia.
  • 3Pathobiological Sciences, Vector-borne Disease Laboratories, School of Veterinary Medicine, Louisiana State University.
  • 4School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA, USA.
  • 5Department of Pathology, Microbiology and Immunology, University of South Carolina, Columbia, SC, USA.

Abstract

INTRODUCTION:

Mosquito salivary proteins are able to induce an antibody response that reflects the level of human-vector contact. IgG antibodies against dengue virus (DENV-IgG) are indicators of previous exposure. The risk of DENV transmission is not only associated to mosquito or dengue factors, but also to socioeconomic factors that may play an important role in the disease epidemiology.

OBJECTIVE:

To determine the effect of the presence of Aedes aegypti mosquitos in different stages in households and the history of dengue exposure on vector-human contact determined by the level of anti-salivary protein antibodies in people living in a Colombian endemic area.

MATERIALS AND METHODS:

A pilot study of 58 households and 55 human subjects was conducted in Norte de Santander, Colombia. A questionnaire for socioeconomic factors was administered and houses were examined for the presence of Ae. aegypti specimens in the aquatic stages. The level of DENV-IgG antibodies (DENV-IgG), in addition to IgG and IgM anti- Ae. aegypti salivary gland extract (SGE) antibodies (SGE-IgG, SGE-IgM) were evaluated by ELISA using blood collected in filter paper.

RESULTS:

We found a significant higher level of SGE-IgG antibodies in subjects living in houses with Ae. aegypti in aquatic stages. We also found a higher concentration of SGE-IgG antibodies in people exposed to DENV, a positive correlation between IgM-SGE and IgG-DENV and a negative correlation with IgG-SGE.

CONCLUSION:

Anti-salivary proteins antibodies are consistent with the presence of Ae. aegypti aquatic stages inside houses and DENV-IgG antibodies concentrations.

[PubMed - in process]
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4.
J Med Entomol. 2016 Feb 3. pii: tjw003. [Epub ahead of print]

Human C5a Protein Participates in the Mosquito Immune Response Against Dengue Virus.

Author information

  • 1Department of Pathology, Microbiology and Immunology, University of South Carolina School of Medicine, Columbia, SC, 29209 (berlinlondo@yahoo.com; Andrea.Troupin@uscmed.sc.edu), berlinlondo@yahoo.com.
  • 2Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, New Orleans, LA, 70130 (cgrippin@tulane.edu), and.
  • 3Microbiology and Clinical Laboratory, Hospital San Juan de Dios, Los Patios - Norte de Santander, Colombia (carocardenasg@hotmail.com).
  • 4Department of Pathology, Microbiology and Immunology, University of South Carolina School of Medicine, Columbia, SC, 29209 (berlinlondo@yahoo.com; Andrea.Troupin@uscmed.sc.edu).

Abstract

Dengue virus (DENV) is transmitted by Aedes spp mosquitoes during a bloodmeal uptake. The bloodmeal consists of host cells, immune factors, and possibly blood-borne pathogens, such as arboviruses. Human cells and immune-related factors, like the complement system, can remain active in the bloodmeal and may be able to interact with pathogens in the mosquito. Previous studies have shown that active complement proteins impact Plasmodium parasite viability in the Anopheles midgut. Thus, we investigated the effects of the human complement on DENV infection in the midgut of Aedes aegypti. Our findings indicate that mosquitoes receiving DENV mixed with normal non-inactivated human serum showed significantly lower viremia than those fed with heat-inactivated serum. This implies that human complement may act to limit DENV infection in the mosquito midgut. In addition, we found that human complement C5a protein was able to directly communicate with mosquito cells, affecting the cell antiviral response against DENV. Our results also show that human C5a protein is able to interact with several membrane-bound mosquito proteins. Together these results suggest an important role of human complement protein in DENV transmission.

© The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

KEYWORDS:

Aedes; dengue; human complement; mosquito

PMID:
26843451
PMCID:
PMC4892811
[Available on 2017-05-01]
DOI:
10.1093/jme/tjw003
[PubMed - as supplied by publisher]
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5.
PLoS Pathog. 2015 Oct 22;11(10):e1005202. doi: 10.1371/journal.ppat.1005202. eCollection 2015.

Dengue Virus Infection of Aedes aegypti Requires a Putative Cysteine Rich Venom Protein.

Author information

  • 1Department of Pathology, Microbiology & Immunology, University of South Carolina School of Medicine, Columbia, South Carolina, United States of America.
  • 2Foundational Sciences, Central Michigan University College of Medicine, Mount Pleasant, Michigan, United States of America.
  • 3L2 Diagnostics, New Haven, Connecticut, United States of America.
  • 4Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana, United States of America.
  • 5Biosecurity Research Institute, Kansas State University, Manhattan, Kansas, United States of America; Diagnostic Medicine and Pathobiology, Kansas State University, Manhattan, Kansas, United States of America.
  • 6Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America; Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America.

Abstract

Dengue virus (DENV) is a mosquito-borne flavivirus that causes serious human disease and mortality worldwide. There is no specific antiviral therapy or vaccine for DENV infection. Alterations in gene expression during DENV infection of the mosquito and the impact of these changes on virus infection are important events to investigate in hopes of creating new treatments and vaccines. We previously identified 203 genes that were ≥5-fold differentially upregulated during flavivirus infection of the mosquito. Here, we examined the impact of silencing 100 of the most highly upregulated gene targets on DENV infection in its mosquito vector. We identified 20 genes that reduced DENV infection by at least 60% when silenced. We focused on one gene, a putative cysteine rich venom protein (SeqID AAEL000379; CRVP379), whose silencing significantly reduced DENV infection in Aedes aegypti cells. Here, we examine the requirement for CRVP379 during DENV infection of the mosquito and investigate the mechanisms surrounding this phenomenon. We also show that blocking CRVP379 protein with either RNAi or specific antisera inhibits DENV infection in Aedes aegypti. This work identifies a novel mosquito gene target for controlling DENV infection in mosquitoes that may also be used to develop broad preventative and therapeutic measures for multiple flaviviruses.

[PubMed - indexed for MEDLINE]
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6.
Parasit Vectors. 2015 Oct 13;8:533. doi: 10.1186/s13071-015-1160-3.

An. gambiae gSG6-P1 evaluation as a proxy for human-vector contact in the Americas: a pilot study.

Author information

  • 1Department of Pathology, Microbiology and Immunology, University of South Carolina, Columbia, SC, USA. blondono@uscmed.sc.edu.
  • 2Department of Pathology, Microbiology and Immunology, University of South Carolina School of Medicine, 6439 Garners Ferry Rd, Bldg 2 Rm C3, Columbia, SC, 29209, USA. blondono@uscmed.sc.edu.
  • 3Laboratory of Parasitic Diseases, National Institutes of Health, NIAID, Bethesda, MD, USA. dramepm@niaid.nih.gov.
  • 4Laboratorio Clínico/Programa Medicina del Viajero, Clínica Alemana, Universidad del Desarrollo, Santiago, Chile. thomas.weitzel@gmail.com.
  • 5Hospital Militar, Santiago, Chile. reinaldo.rosas@gmail.com.
  • 6Department of Tropical Medicine, Tulane University, New Orleans, LA, USA. cgrippin@tulane.edu.
  • 7Hospital Los Patios, Los Patios, Norte de Santander, Colombia. carocardenasg@hotmail.com.
  • 8Hospital Emiro Quintero Canizales, Ocana, Norte de Santander, Colombia. marcealvareza@gmail.com.
  • 9Department of Tropical Medicine, Tulane University, New Orleans, LA, USA. wesson@tulane.edu.
  • 10Institut de Recherche pour le Développement-IRD, Bouaké, Côte d'Ivoire. anne.poinsignon@ird.fr.
  • 11Institut de Recherche pour le Développement-IRD, Bouaké, Côte d'Ivoire. franck.remoue@ird.fr.
  • 12Department of Pathology, Microbiology and Immunology, University of South Carolina, Columbia, SC, USA. Tonya.Colpitts@uscmed.sc.edu.

Abstract

BACKGROUND:

During blood meal, the female mosquito injects saliva able to elicit an immune response in the vertebrate. This immune response has been proven to reflect the intensity of exposure to mosquito bites and risk of infection for vector transmitted pathogens such as malaria. The peptide gSG6-P1 of An. gambiae saliva has been demonstrated to be antigenic and highly specific to Anopheles as a genus. However, the applicability of gSG6-P1 to measure exposure to different Anopheles species endemic in the Americas has yet to be evaluated. The purpose of this pilot study was to test whether human participants living in American countries present antibodies able to recognize the gSG6-P1, and whether these antibodies are useful as a proxy for mosquito bite exposure and malaria risk.

METHODS:

We tested human serum samples from Colombia, Chile, and the United States for the presence of IgG antibodies against gSG6-P1 by ELISA. Antibody concentrations were expressed as delta optical density (ΔOD) of each sera tested in duplicates. The difference in the antibody concentrations between groups was tested using the nonparametric Mann Whitney test (independent groups) and the nonparametric Wilcoxon matched-pairs signed rank test (dependent groups). All differences were considered significant with a P < 0.05.

RESULTS:

We found that the concentration of gSG6-P1 antibodies was significantly correlated with malaria infection status and mosquito bite exposure history. People with clinical malaria presented significantly higher concentrations of IgG anti-gSG6-P1 antibodies than healthy controls. Additionally, a significant raise in antibody concentrations was observed in subjects returning from malaria endemic areas.

CONCLUSION:

Our data shows that gSG6-P1 is a suitable candidate for the evaluation of exposure to Anopheles mosquito bites, risk of malaria transmission, and effectiveness of protection measures against mosquito bites in the Americas.

[PubMed - indexed for MEDLINE]
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7.
Am J Trop Med Hyg. 2015 Oct;93(4):869-74. doi: 10.4269/ajtmh.15-0130. Epub 2015 Jul 20.

Long-Lasting Permethrin-Impregnated Clothing Protects Against Mosquito Bites in Outdoor Workers.

Author information

  • 1Department of Pathology, Immunology and Microbiology, University of South Carolina, Columbia, South Carolina; Department of Tropical Medicine, Tulane University, New Orleans, Louisiana; Department of Epidemiology, Gillings School of Global Public Health, Chapel Hill, North Carolina; Department of Entomology, North Carolina State University, Raleigh, North Carolina; Department of Pathobiological Sciences, Louisiana State University, Baton Rouge, Louisiana berlinlondo@yahoo.com.
  • 2Department of Pathology, Immunology and Microbiology, University of South Carolina, Columbia, South Carolina; Department of Tropical Medicine, Tulane University, New Orleans, Louisiana; Department of Epidemiology, Gillings School of Global Public Health, Chapel Hill, North Carolina; Department of Entomology, North Carolina State University, Raleigh, North Carolina; Department of Pathobiological Sciences, Louisiana State University, Baton Rouge, Louisiana.

Abstract

Outdoor exposure to mosquitoes is a risk factor for many diseases, including malaria and dengue. We have previously shown that long-lasting permethrin-impregnated clothing protects against tick and chigger bites in a double-blind randomized controlled trial in North Carolina outdoor workers. Here, we evaluated whether this clothing is protective against mosquito bites by measuring changes in antibody titers to mosquito salivary gland extracts. On average, there was a 10-fold increase in titer during the spring and summer when mosquito exposure was likely to be the highest. During the first year of the study, the increase in titer in subjects wearing treated uniforms was 2- to 2.5-fold lower than that of control subjects. This finding suggests that long-lasting permethrin-impregnated clothing provided protection against mosquito bites.

© The American Society of Tropical Medicine and Hygiene.

PMID:
26195460
PMCID:
PMC4596613
[Available on 2016-10-07]
DOI:
10.4269/ajtmh.15-0130
[PubMed - indexed for MEDLINE]
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8.
J Med Entomol. 2014 Sep;51(5):1043-50.

Factors associated with peridomestic Triatoma sanguisuga (Hemiptera: Reduviidae) presence in southeastern Louisiana.

Abstract

Although rare, there have been isolated reports of autochthonous transmission of Trypanosoma cruzi Chagas in the United States. In June 2006, a human case of domestically transmitted T. cruzi was identified in southern Louisiana. To examine the localized risk of human T. cruzi infection in the area surrounding the initial human case, environmental surveys of households in the area and a serological survey of the residents were performed between September 2008 and November 2009. Human T. cruzi infection was determined using a rapid antigen field test, followed by confirmatory enzyme-linked immunosorbent assay testing in the laboratory. A perimeter search of each participating residence for Triatoma sanguisuga (LeConte), the predominant local triatomine species, was also performed. No participating individuals were positive for antibodies against T. cruzi; however, high levels of T. cruzi infection (62.4%) were detected in collected T. sanguisuga. Households with T. sanguisuga presence were less likely to use air conditioning, and more likely to have either chickens or cats on the property. While the human risk for T cruzi infection in southeastern Louisiana is low, a high prevalence of infected T. sanguisuga does indicate a substantial latent risk for T. cruzi peridomestic transmission. Further examination of the behavior and ecology of T. sanguisuga in the region will assist in refining local T. cruzi risk associations.

PMID:
25276935
[PubMed - indexed for MEDLINE]
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9.
Parasit Vectors. 2014 May 30;7:252. doi: 10.1186/1756-3305-7-252.

Infection with dengue-2 virus alters proteins in naturally expectorated saliva of Aedes aegypti mosquitoes.

Author information

  • 1Department of Pathobiological Sciences, Vector-borne Disease Laboratories, Louisiana State University, School of Veterinary Medicine, Baton Rouge, LA, USA. cmores@lsu.edu.

Abstract

BACKGROUND:

Dengue virus (DENV) is responsible for up to approximately 300 million infections and an increasing number of deaths related to severe manifestations each year in affected countries throughout the tropics. It is critical to understand the drivers of this emergence, including the role of vector-virus interactions. When a DENV-infected Aedes aegypti mosquito bites a vertebrate, the virus is deposited along with a complex mixture of salivary proteins. However, the influence of a DENV infection upon the expectorated salivary proteome of its vector has yet to be determined.

METHODS:

Therefore, we conducted a proteomic analysis using 2-D gel electrophoresis coupled with mass spectrometry based protein identification comparing the naturally expectorated saliva of Aedes aegypti infected with DENV-2 relative to that of uninfected Aedes aegypti.

RESULTS:

Several proteins were found to be differentially expressed in the saliva of DENV-2 infected mosquitoes, in particular proteins with anti-hemostatic and pain inhibitory functions were significantly reduced. Hypothetical consequences of these particular protein reductions include increased biting rates and transmission success, and lead to alteration of transmission potential as calculated in our vectorial capacity model.

CONCLUSIONS:

We present our characterizations of these changes with regards to viral transmission and mosquito blood-feeding success. Further, we conclude that our proteomic analysis of Aedes aegypti saliva altered by DENV infection provides a unique opportunity to identify pro-viral impacts key to virus transmission.

[PubMed - indexed for MEDLINE]
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10.
Am J Trop Med Hyg. 2014 Mar;90(3):431-7. doi: 10.4269/ajtmh.13-0412. Epub 2014 Jan 20.

Effect of dengue-2 virus infection on protein expression in the salivary glands of Aedes aegypti mosquitoes.

Author information

  • 1School of Veterinary Medicine, Department of Pathobiological Sciences, Louisiana State University, Baton Rouge, Louisiana; Faculty of Health, Department of Microbiology, University of Pamplona, Pamplona, Norte de Santander, Colombia.

Abstract

Dengue virus (DENV) is the most important mosquito-transmitted flavivirus that is transmitted throughout the tropical and subtropical regions of the world. The primary mosquito vector of DENV in urban locations is Aedes aegypti. Key to understanding the transmission of DENV is the relationship between pathogen and vector. Accordingly, we report our preliminary characterization of the differentially expressed proteins from Ae. aegypti mosquitoes after DENV infection. We investigated the virus-vector interaction through changes in the proteome of the salivary glands of mosquitoes with disseminated DENV serotype 2 (DENV-2) infections using two-dimensional gel electrophoresis and identification by mass spectrometry. Our findings indicate that DENV-2 infection in the Ae. aegypti salivary gland alters the expression of structural, secreted, and metabolic proteins. These changes in the salivary gland proteome highlight the virally influenced environment caused by a DENV-2 infection and warrant additional investigation to determine if these differences extend to the expectorated saliva.

[PubMed - indexed for MEDLINE]
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11.
PLoS One. 2013 Dec 2;8(12):e81211. doi: 10.1371/journal.pone.0081211. eCollection 2013.

Use of anti-Aedes aegypti salivary extract antibody concentration to correlate risk of vector exposure and dengue transmission risk in Colombia.

Author information

  • 1Louisiana State University, Baton Rouge, Louisiana, United States of America ; Universidad de Pamplona, Pamplona, Colombia.

Abstract

Norte de Santander is a region in Colombia with a high incidence of dengue virus (DENV). In this study, we examined the serum concentration of anti-Aedes salivary gland extract (SGE) antibodies as a biomarker of DENV infection and transmission, and assessed the duration of anti-SGE antibody concentration after exposure to the vector ceased. We also determined whether SGE antibody concentration could differentiate between positive and negative DENV infected individuals and whether there are differences in exposure for each DENV serotype. We observed a significant decrease in the concentration of IgG antibodies at least 40 days after returning to an "Ae. aegypti-free" area. In addition, we found significantly higher anti-SGE IgG concentrations in DENV positive patients with some difference in exposure to mosquito bites among DENV serotypes. We conclude that the concentration of IgG antibodies against SGE is an accurate indicator of risk of dengue virus transmission and disease presence.

[PubMed - indexed for MEDLINE]
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12.
Acta Trop. 2012 Jan;121(1):6-12. doi: 10.1016/j.actatropica.2011.09.005. Epub 2011 Sep 29.

Genetic diversity in the merozoite surface protein 1 and 2 genes of Plasmodium falciparum from the Artibonite Valley of Haiti.

Author information

  • 1Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, New Orleans, LA 70112, USA. berlinlondo@yahoo.com

Abstract

Describing genetic diversity of the Plasmodium falciparum parasite provides important information about the local epidemiology of malaria. In this study, we examined the genetic diversity of P. falciparum isolates from the Artibonite Valley in Haiti using the allelic families of merozoite surface protein 1 and 2 genes (msp-1 and msp-2). The majority of study subjects infected with P. falciparum had a single parasite genotype (56% for msp-1 and 69% for msp-2: n=79); 9 distinct msp-1 genotypes were identified by size differences on agarose gels. K1 was the most polymorphic allelic family with 5 genotypes (amplicons from 100 to 300 base pairs [bp]); RO33 was the least polymorphic, with a single genotype (120-bp). Although both msp-2 alleles (3D7/IC1, FC27) had similar number of genotypes (n=4), 3D7/IC1 was more frequent (85% vs. 26%). All samples were screened for the presence of the K76T mutation on the P. falciparum chloroquine resistance transporter (pfcrt) gene with 10 of 79 samples positive. Of the 2 (out of 10) samples from individuals follow-up for 21 days, P. falciparum parasites were present through day 7 after treatment with chloroquine. No parasites were found on day 21. Our results suggest that the level of genetic diversity is low in this area of Haiti, which is consistent with an area of low transmission.

Copyright © 2011 Elsevier B.V. All rights reserved.

[PubMed - indexed for MEDLINE]
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13.
J Med Entomol. 2010 Nov;47(6):1156-63.

Antibody response against Anopheles albimanus (Diptera: Culicidae) salivary protein as a measure of mosquito bite exposure in Haiti.

Author information

  • 1Department of Tropical Medicine, SPHTM, Tulane University, New Orleans, LA 70112, USA. blondono@tulane.edu

Abstract

Antibodies against arthropod saliva have shown to be a good marker of bite exposure. Because Anopheles albimanus Wiedemann (Diptera: Culicidae) is the principal malaria vector in Haiti, we evaluated the immune response against salivary gland extract (SGE) of this species in malaria-positive and malaria-negative subjects from this country. The results showed that the level of anti-SGE immunoglobulin (Ig)G antibodies was higher in patients with clinical malaria than those in malaria uninfected people living in the same region. In addition, a significant positive correlation between the level of anti-An. albimanus IgG and IgM antibody levels was observed. These results suggest that antibodies against An. albimanus saliva, especially IgG, are useful markers of mosquito bite exposure in Haiti.

PMID:
21175067
[PubMed - indexed for MEDLINE]
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14.
Emerg Infect Dis. 2009 May;15(5):735-40. doi: 10.3201/eid1505.081063.

Chloroquine-resistant haplotype Plasmodium falciparum parasites, Haiti.

Author information

  • 1Tulane University, New Orleans, Louisiana, USA.

Abstract

Plasmodium falciparum parasites have been endemic to Haiti for >40 years without evidence of chloroquine (CQ) resistance. In 2006 and 2007, we obtained blood smears for rapid diagnostic tests (RDTs) and filter paper blots of blood from 821 persons by passive and active case detection. P. falciparum infections diagnosed for 79 persons by blood smear or RDT were confirmed by PCR for the small subunit rRNA gene of P. falciparum. Amplification of the P. falciparum CQ resistance transporter (pfcrt) gene yielded 10 samples with amplicons resistant to cleavage by ApoI. A total of 5 of 9 samples had threonine at position 76 of pfcrt, which is consistent with CQ resistance (haplotypes at positions 72-76 were CVIET [n = 4] and CVMNT [n = 1]); 4 had only the wild-type haplotype associated with CQ susceptibility (CVMNK). These results indicate that CQ-resistant haplotype P. falciparum malaria parasites are present in Haiti.

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15.
Emerg Infect Dis. 2007 Oct;13(10):1494-6. doi: 10.3201/eid1310.070567.

Prevalence of Plasmodium falciparum infection in rainy season, Artibonite Valley, Haiti, 2006.

Author information

  • 1Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana 70112, USA. teisele@tulane.edu

Abstract

We conducted a population-based survey to estimate the prevalence of Plasmodium falciparum infection among persons older than 1 month in the Artibonite Valley of Haiti during the high malaria transmission season in 2006. Results from PCR for 714 persons showed a prevalence of 3.1% for P. falciparum infection.

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16.
Phytother Res. 2006 Jun;20(6):444-7.

Prevention of sporogony of Plasmodium vivax in Anopheles albimanus by steroids of Solanum nudum Dunal (Solanaceae).

Author information

  • 1Grupo Malaria, Universidad de Antioquia, Medellín, Colombia.

Abstract

The sporontocidal activity of three steroids (SN-1, SN-2 and SN-4) from Solanum nudum Dunal (Solanaceae) was determined against naturally circulating isolates of Plasmodium vivax in Anopheles albimanus. Laboratory-reared Anopheles albimanus mosquitoes were infected with P. vivax from gametocytemic blood of volunteers resident in Buenaventura, Valle del Cauca (Colombian Pacific Coast) by using an artificial membrane feeder. Prior to mosquito feeding, gametocytemic blood was centrifuged, plasma was separated, packed blood red cells were washed with RPMI 1640 and then resuspended in non-immune AB serum, then the steroids were added at different doses. On day 7 after infection, the presence and number of oocysts in mosquitoes was determined. The steroid SN-2 reduced the infection of mosquitoes by 90% and the mean number of oocysts by 60%. These data confirmed that the experimental steroid is capable of interrupting the sporogonic development of P. vivax in Anopheles albimanus. This experimental steroid has potential for transmission blocking in vivax malaria.

[PubMed - indexed for MEDLINE]
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17.
Phytother Res. 2006 Apr;20(4):267-73.

Effect of Solanum nudum Dunal (Solanaceae) steroids on hepatic trophozoites of Plasmodium vivax.

Author information

  • 1Grupo Malaria, Universidad de Antioquia, Medellín, Colombia.

Erratum in

  • Phytother Res. 2006 Jun;20(6):518.

Abstract

Steroids isolated from the plant Solanum nudum showed antiplasmodial activity against the blood stages of Plasmodium falciparum. It has been demonstrated that these steroids are neither mutagenic in vitro nor clastogenic in vivo. This study evaluated the effect of five steroids of S. nudum (SN-1, SN-2, SN-3, SN-4 and SN-5) on hepatic trophozoites of P. vivax, using an experimental design, non-balanced, with blind determination of the effect expressed as the percentage reduction of hepatic trophozoites. The sporozoites used to inoculate human hepatoma cells HepG2-A16 were obtained from gametocytemic blood of volunteers infected only with P. vivax, and passed into laboratory-reared Anopheles albimanus mosquitoes. Steroids were added at three different doses (100, 10 and 1 microg/mL) just after inoculation of the cells with sporozoites. The effect was determined by indirect immunofluorescence assays using the monoclonal antibodies Pv210 or Pv47E-2E10 and steroid cytotoxicity on HepG2-A16 cells was assessed by the MTT method. All the steroids reduced the number of hepatic P. vivax trophozoites, SN-2 and SN-4 reduced the number of hepatic trophozoites by 47% and 39% (p < 0.05), respectively.

Copyright 2006 John Wiley & Sons, Ltd.

[PubMed - indexed for MEDLINE]
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18.
Biomedica. 2002 Dec;22(4):466-75.

[Comparison between OptiMAL and the thick smear tests for malaria diagnosis in an endemic area during a non-epidemic period].

[Article in Spanish]

Author information

  • 1Grupo Malaria, Facultad de Medicina, Universidad de Antioquia.

Abstract

The capacity of Optimal to diagnose malaria was compared with the thick smear test in two representative samples, one with acute febrile syndrome (AFS) n = 107, and another diagnosed by thick smear test (AFS + M) n = 82. The samples were chosen from patients at the malaria diagnostic clinic in Turbo, Antioquia, Colombia, between June and August 2000. The study was designed to be descriptive, prospective, and cross-sectional. The two tests were applied simultaneously in the AFS group (parallel, double blind design), and in sequential form in the AFS + M group. The thick smear test was the standard test. Optimal tests were carried out according to the manufacturer's instructions. In the parallel design, Optimal showed, for Plasmodium falciparum, a sensitivity of 40% [95% CI: 18-67], a specificity of 98% (95% CI: 92-100) and positive and negative predictive values of 75% (95% CI: 36-96) and 91% (95% CI: 83-96%), respectively. For Plasmodium vivax, it showed a sensitivity of 97% (95% CI: 82-100), a specificity of 89% (95% CI: 80-95) and positive and negative predictive values of 79% (95% CI: 62-90) and 98% (95% CI: 91-100). With the sequential design, Optimal showed a sensitivity of 67% (95% CI: 52-79) and 97% (95% CI: 83-100) for P. falciparum and P. vivax, respectively. For P. falciparum, the sensitivity was directly proportional to the parasitemia, while the sensitivity for P. vivax was independent from the parasitemia. The diagnostic values and operative characteristics of the thick smear test surpassed the Optimal test in its sensitivity for P. falciparum; the specificities were similar. Both tests were nearly identical in their diagnostic capacity for P. vivax. These results recommend that the thick smear test be retained as a routine or reference test for malaria diagnosis, with Optimal used as an ancillary test.

PMID:
12596444
[PubMed - indexed for MEDLINE]
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