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Pallecchi L.,University of Siena | Riccobono E.,University of Siena | Sennati S.,University of Siena | Trigoso C.,University of Florence | And 3 more authors.
Antimicrobial Agents and Chemotherapy | Year: 2010

In this work, we have characterized two small ColE-like plasmids (pECY6-7, 2.7 kb in size, and pECC14-9, of 3.0 kb), encoding the QnrB19 quinolone resistance determinant, that were carried by several clonally unrelated quinolone-resistant commensal Escherichia coli strains isolated from healthy children living in different urban areas of Peru and Bolivia. The two plasmids are closely related to each other and carry the qnrB19 gene as the sole resistance determinant, located in a conserved genetic context between the plasmid RNAII sequence (which controls plasmid replication) and the plasmid Xer site (involved in plasmid dimer resolution). ISEcp1-like or other putative insertion sequences are not present in the qnrB19-flanking regions or elsewhere on the plasmids. Since we previously observed a high prevalence (54%) of qnrB genes in the metagenomes of commensal enterobacteria from the same population of healthy children, the presence of pECY6-7- and pECC14-9-like plasmids in those qnrB-positive metagenomes was investigated by PCR mapping. Both plasmids were found to be highly prevalent (67% and 16%, respectively) in the qnrB-positive metagenomes, suggesting that dissemination of these small plasmids played a major role in the widespread dissemination of qnrB genes observed in commensal enterobacteria from healthy children living in those areas. Copyright © 2010, American Society for Microbiology. All Rights Reserved.


Lardeux F.,Institute Of Recherche Pour Le Developpement Ird | Lardeux F.,Instituto Nacional Of Laboratorios Of Salud Inlasa | Aliaga C.,Institute Of Recherche Pour Le Developpement Ird | Aliaga C.,Instituto Nacional Of Laboratorios Of Salud Inlasa | And 3 more authors.
Comptes Rendus - Biologies | Year: 2012

Using the Anopheles gambiae Giles genome as a template, we designed, screened and identified 14 novel Exon-Primed Intron-Crossing (EPIC) PCR primer pairs for Anopheles pseudopunctipennis Theobald 1901, a major vector of human Plasmodium sp. in South America. These primers were designed to target the conserved regions flanking consecutive exons of different genes and enabled the amplification of 17 loci of which nine were polymorphic. Polymorphisms at these loci ranged from two to four alleles. Intron length polymorphism analysis is a useful tool, which will allow the study of the population structure of this mosquito species, which remains poorly understood. © 2012 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.


Lardeux F.,Institute Of Recherche Pour Le Developpement Ird | Depickere S.,Institute Of Recherche Pour Le Developpement Ird | Aliaga C.,Institute Of Recherche Pour Le Developpement Ird | Chavez T.,Instituto Nacional Of Laboratorios Of Salud Inlasa | Zambrana L.,Gabriel René Moreno Autonomous University
Transactions of the Royal Society of Tropical Medicine and Hygiene | Year: 2014

Background: Triatoma infestans is the main vector of Chagas disease in the southern cone countries. Present control strategies based on indoor and outdoor residual insecticide spraying are not sufficient to control disease transmission, particularly in Bolivia. Techniques based on the management of the human environment may be good alternatives or supplements. Methods: Social and entomological surveys were carried out in four villages of Bolivia situated in the dry inter-Andean Valleys and the Chaco region. Risk factors for house infestation by T. infestanswere identified, and an ecohealth intervention based on education and community participation was carried out to reduce the risks of house infestation. It consisted of implementing simple and low cost vector control techniques such as coating of mud walls, cleaning activities and removal of poultry that enter rooms to lay eggs. Results: The eco-health intervention significantly reduced the number of infested bedrooms, the mean abundance of T. infestans in bedrooms and beds, especially in the Chaco region. Mud wall coating was well accepted and could be proposed as a supplementary tool to the National Program of Chagas Disease Control to enhance the effects of insecticide sprayings. Conclusions: Even if cleaning activities were still neglected, community participation proved to be effective in reducing house infestation. © The author 2015.


Lardeux F.,Institute Of Recherche Pour Le Developpement Ird | Lardeux F.,Montpellier University | Lardeux F.,Instituto Nacional Of Laboratorios Of Salud Inlasa | Aliaga C.,Institute Of Recherche Pour Le Developpement Ird | And 4 more authors.
Malaria Journal | Year: 2013

Background: Anopheles (Anopheles) pseudopunctipennis is a recognized malaria vector in the slopes of the Andes of Bolivia. There, other species might be involved in malaria transmission and one candidate could be Anopheles argyritarsis. Although it is generally admitted that this species is not a malaria vector in the neotropical region, its potential role in transmission is still controversial and this situation has to be cleared, at least for Bolivia. Comparing the vectorial efficiency of An. pseudopunctipennis with that of An. argyritarsis could solve the question. Methods. The two species were sampled throughout Bolivia to estimate their degree of co-existence in their distribution range. Vectorial efficiencies of the two species were compared in two ecologically different localities where the species were sympatric by analysing their vectorial capacities and components (i e, human biting rates, human biting index, survival, durations of the gonotrophic cycle and extrinsic cycle), and the entomological inoculation rates (EIR). Mosquitoes were sampled monthly during more than one year in the two localities. A monthly sample consisted in hourly captures in four houses (inside and outside) in each locality, during four consecutive nights. Climatic variables (temperature, humidity, potential evapo-transpiration and precipitations) were recorded to better understand variability in the entomological parameters. Relationships were analysed using multivariate methods. Results: Anopheles pseudopunctipennis and An. argyritarsis are "altitude" species, sharing the same geographical distribution range in the Andes of Bolivia. No Plasmodium parasite was identified in An. argyritarsis and estimates of the vectorial capacity indicated that it is not a malaria vector in the two studied localities, unlike An. pseudopunctipennis which showed positive EIRs. This latter species, although not a very good malaria vector, exhibited better life traits values and better behavioural characteristics in favour of transmission as compared to An. argyritarsis. Conclusions: In the Andes of Bolivia, above 1000 m of altitude, An. pseudopunctipennis is likely to be the only malaria vector. There, it is present almost everywhere and priority control effort should be directed toward this species. Below 1000 m of altitude, vector incrimination should also be focused on other sympatric species (likely not An. argyritarsis) that might be locally important. From the present study, candidates would be among Anopheles rangeli, Anopheles triannulatus s.l., Anopheles trinkae, Anopheles nuneztovari s.l., Anopheles oswaldoi s.l. and Anopheles benarrochi s.l. © 2013 Lardeux et al.; licensee BioMed Central Ltd.


Chippaux J.-P.,IRD Montpellier | Chippaux J.-P.,University of Paris Descartes | Chippaux J.-P.,Instituto Nacional Of Laboratorios Of Salud Inlasa | Postigo J.R.,IRD Montpellier
Toxicon | Year: 2014

No information has been yet published on snakebite in Bolivia. The country includes very different ecological situations leading to various epidemiological risks. A study has been carried out to evaluate the incidence and location of snakebite, particularly in relation with altitude, in order to improve management. Investigations on snakebite epidemiology were based on a) cases treated in health facilities as reported by health authorities and b) household surveys carried out in areas with high variations of altitude, in various regions of Bolivia. An average of 700 bites was treated each year in Bolivia (national annual incidence = 8 bites per 100,000 people) with a great disparity between districts. Household surveys showed annual incidences ranged from 30 to 110 bites per 100,000 inhabitants depending on location. Annual mortality ranged 0.1-3.9 per 100,000 people. A significant and constant inverse correlation was shown between snakebite incidence and altitude, which may be explained by both snake and human distributions and activities. Notification of snakebite is useful for improving patient management and informing antivenom distribution. It should also involve the report of deaths and clinical details of envenomation. © 2014 Elsevier Ltd. All rights reserved.


Salas Clavijo N.A.,IRD Montpellier | Postigo J.R.,IRD Montpellier | Schneider D.,IRD Montpellier | Schneider D.,University of Paris Descartes | And 6 more authors.
Acta Tropica | Year: 2012

Congenital transmission of Chagas disease stand out as a major public health problem since the vector control was performed in all endemic areas and has shown its effectiveness. An epidemiological study was performed in three maternity hospitals of the city of Santa Cruz de la Sierra, Bolivia from 2006 to 2008. The serological screening for Trypanosoma cruzi infection was carried out in 15,767 pregnant women. Chagas infection was detected in 3725 women (23.6%), who gave birth to 125 newborns infected by T. cruzi at birth, representing an incidence of 790 per 100,000 births during a period of 16 months and a vertical transmission rate by 3.4%. There was a significant difference between hospitals that might be explained by socio-economic origins of mothers and diagnostic constraints. © 2012 Elsevier B.V.


Panzera F.,University of the Republic of Uruguay | Pita S.,University of the Republic of Uruguay | Nattero J.,National University of Cordoba | Nattero J.,University of Buenos Aires | And 6 more authors.
Parasites and Vectors | Year: 2015

Background: Chagas disease vectors (Hemiptera-Reduviidae) comprise more than 140 blood-sucking insect species of the Triatominae subfamily. The largest genus is Triatoma, subdivided in several complexes and subcomplexes according to morphology, ecology and genetic features. One of them is the sordida subcomplex, involving four species: Triatoma sordida, T. guasayana, T. garciabesi and T. patagonica. Given the great morphological similarity of these species, their taxonomic identification, evolutionary relationships and population differentiation have been controversial for many years and even today remain under discussion. Methods: We simultaneously analyzed two chromosomal markers, C-heterochromatin distribution and 45S ribosomal genes chromosomal position, of 139 specimens from several sordida subcomplex populations from Argentina, Bolivia, Brazil and Paraguay, collected both in nature and from several established insectaries. Our results were compared with COI sequences deposited in GenBank. Results: We recognized five chromosomal taxa with putative hybrids, which each differ in at least one chromosome marker. Most of them present significant differences in their mtDNA sequences. Conclusion: The chromosomal taxa here show a significant chromosome differentiation involving changes in the C-heterochromatin content and in the ribosomal clusters position. This paper identifies several erroneously classified populations by morphological methods, delimits the geographical distribution of each taxon and proposes the existence of a new cryptic species, widely distributed in Argentina. We also suggest that sordida sibling species involve closely related as well as evolutionary distant species. Taxonomic status of each chromosomal taxon is discussed considering phenotypic and genetic results previously published. © 2015 Panzera et al.


PubMed | University of the Republic of Uruguay, Instituto Oswaldo, Instituto Paraguayo Of Tecnologia Agraria, Instituto Nacional Of Laboratorios Of Salud Inlasa and 3 more.
Type: | Journal: Parasites & vectors | Year: 2015

Chagas disease vectors (Hemiptera-Reduviidae) comprise more than 140 blood-sucking insect species of the Triatominae subfamily. The largest genus is Triatoma, subdivided in several complexes and subcomplexes according to morphology, ecology and genetic features. One of them is the sordida subcomplex, involving four species: Triatoma sordida, T. guasayana, T. garciabesi and T. patagonica. Given the great morphological similarity of these species, their taxonomic identification, evolutionary relationships and population differentiation have been controversial for many years and even today remain under discussion.We simultaneously analyzed two chromosomal markers, C-heterochromatin distribution and 45S ribosomal genes chromosomal position, of 139 specimens from several sordida subcomplex populations from Argentina, Bolivia, Brazil and Paraguay, collected both in nature and from several established insectaries. Our results were compared with COI sequences deposited in GenBank.We recognized five chromosomal taxa with putative hybrids, which each differ in at least one chromosome marker. Most of them present significant differences in their mtDNA sequences.The chromosomal taxa here show a significant chromosome differentiation involving changes in the C-heterochromatin content and in the ribosomal clusters position. This paper identifies several erroneously classified populations by morphological methods, delimits the geographical distribution of each taxon and proposes the existence of a new cryptic species, widely distributed in Argentina. We also suggest that sordida sibling species involve closely related as well as evolutionary distant species. Taxonomic status of each chromosomal taxon is discussed considering phenotypic and genetic results previously published.


Buitrago N.L.R.,University Institute of La Paz | Bosseno M.F.,University Institute of La Paz | Bosseno M.F.,Instituto Nacional Of Laboratorios Of Salud Inlasa | Waleckx E.,University Institute of La Paz | And 6 more authors.
Infection, Genetics and Evolution | Year: 2013

We analyzed the food sources of Bolivian wild Triatoma infestans (the main vector of Chagas disease in this country), to assess the role of these populations in the epidemiological context of Chagas disease. Ninety-eight blood meals were identified by heteroduplex assay and sequencing. Most of them were from wild mammals but surprisingly 27 were from humans. This brings to light the occurrence of human-vector contacts at risk of Trypanosoma cruzi transmission in the wild environment by highly infected insects. © 2013 Elsevier B.V.


PubMed | CIRAD - Agricultural Research for Development and Instituto Nacional Of Laboratorios Of Salud Inlasa
Type: | Journal: Parasites & vectors | Year: 2016

Chagas disease is a major public health problem in Latin America. Its etiologic agent, Trypanosoma cruzi, is mainly transmitted through the contaminated faeces of blood-sucking insects called triatomines. Triatoma infestans is the main vector in various countries in South America and recently, several foci of wild populations of this species have been described in Bolivia and other countries. These wild populations are suspected of affecting the success of insecticide control campaigns being carried out in South America. To assess the risk that these T. infestans populations pose to human health, it is helpful to determine blood meal sources.In the present work, blood meals were identified in various Bolivian wild T. infestans populations and in three specific areas, in both wild and intra-peridomestic populations to assess the links between wild and domestic cycles of T. cruzi transmission. PCR-HDA and sequencing of Cytb gene were used to identify these blood meal sources.Fourteen vertebrate species were identified as wild blood meal sources. Of those, the most prevalent species were two Andean endemic rodents, Octodontomys gliroides (36%) and Galea musteloides (30%), while humans were the third most prevalent source (18.7%). Of 163 blood meals from peridomestic areas, more than half were chickens, and the others were generally domestic animals or humans. Interestingly, blood from wild animals was identified in triatomines captured in the peridomestic and domestic environment, and blood from domestic animals was found in triatomines captured in the wild, revealing links between wild and domestic cycles of T. cruzi transmission.The current study suggests that wild T. infestans attack humans in the wild, but is also able to bite humans in domestic settings before going back to its natural environment. These results support the risk to human health posed by wild populations of T. infestans.

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