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1.
Med Vet Entomol ; 33(1): 44-55, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30168152

RESUMO

Culex quinquefasciatus Say (Diptera: Culicidae), an important vector of West Nile virus (WNV) in the U.S.A., was first detected on the Galápagos Islands (Ecuador) in the 1980s. However, little is known of its ecology, distribution or capacity for arbovirus transmission in the Galápagos. We characterize details of lifecycle (including gonotrophic period), temporal abundance, spatial distribution, vector competence and host-feeding behaviour. Culex quinquefasciatus was detected on five islands of the Galápagos during 2006-2011. A period of 7-14 days was required for egg-adult emergence; water salinity above 5 ppt was demonstrated to hinder larval development. Blood-meal analysis indicated feeding on reptiles, birds and mammals. Assessment of WNV vector competency of Galápagos C. quinquefasciatus showed a median infectious dose of 7.41 log10 plaque-forming units per millilitre and evidence of vertical transmission (minimal filial infection rate of 3.7 per 1000 progeny). The distribution of C. quinquefasciatus across the archipelago could be limited by salt intolerance, and its abundance constrained by high temperatures. Feeding behaviour indicates potential to act as a bridge vector for transmission of pathogens across multiple taxa. Vertical transmission is a potential persistence mechanism for WNV on Galápagos. Together, our results can be used for epidemiological assessments of WNV and target vector control, should this pathogen reach the Galápagos Islands.


Assuntos
Distribuição Animal , Culex/fisiologia , Características de História de Vida , Mosquitos Vetores/fisiologia , Febre do Nilo Ocidental/epidemiologia , Animais , Culex/crescimento & desenvolvimento , Equador/epidemiologia , Comportamento Alimentar , Feminino , Espécies Introduzidas , Masculino , Mosquitos Vetores/crescimento & desenvolvimento , Risco , Tolerância ao Sal , Febre do Nilo Ocidental/virologia , Vírus do Nilo Ocidental/fisiologia
2.
Infect Genet Evol ; 12(3): 577-85, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22342744

RESUMO

This paper presents the first evaluation of the molecular epidemiology of Mycobacterium tuberculosis in Peru. We characterised 323 isolates using spoligotyping and mycobacterial interspersed repetitive units variable number tandem repeats (MIRU-VNTR) typing. We aimed to determine the levels of genetic diversity and genetic differentiation among and within Peruvian isolates and the epidemiological factors which may be driving patterns of population structure and evolution of M. tuberculosis in Peru. Our results compared to the fourth international spoligotyping database (SpolDB4) and MIRU-VNTRplus, show that the main M. tuberculosis families present are Latin American-Mediterranean, Haarlem, T, and Beijing. Bayesian clustering recovered 15 groups in the Peruvian M. tuberculosis isolates, among which two were composed mainly of orphans, implying the presence of native "Peruvian" strains not previously reported. Variable levels of association with drug resistance were observed, with Beijing genotypes not showing any association with multidrug resistance, while in other groups MIRU-VNTR loci 2, 23, 31, and 40 were found to be associated with the multidrug-resistant tuberculosis (MDR-TB) phenotype, suggesting that a linkage disequibrium between these MIRU and drug resistance loci may be present. Genetic differentiation was present among drug resistant and sensitive strains. Ethambutol appeared to be the main driver of differentiation, suggesting that strong selection pressure could have been exerted by drug treatment in Peru over recent years.


Assuntos
Técnicas de Tipagem Bacteriana/métodos , Farmacorresistência Bacteriana Múltipla , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/genética , Adolescente , Adulto , Alelos , Teorema de Bayes , Bases de Dados Genéticas , Etambutol/farmacologia , Feminino , Variação Genética , Genótipo , Humanos , Desequilíbrio de Ligação , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Repetições Minissatélites , Tipagem Molecular/métodos , Mycobacterium tuberculosis/isolamento & purificação , Mycobacterium tuberculosis/patogenicidade , Peru/epidemiologia , Filogenia , Seleção Genética , Escarro/microbiologia , Tuberculose/epidemiologia , Tuberculose/microbiologia , Adulto Jovem
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