Isolamento de amebas de vida livre potencialmente patogênicas em poeira de hospitais

OBJECTIVE: To evaluate the occurrence of free-living amoebas of the genera Acanthamoeba and Naegleria is dust samples colleted in two hospitals. METHODS: One-hundred and thirty-two dust samples were collected in two hospitals in Brazil. Hospital collection sites were the following: intensive care unit, operation rooms, nursery, kitchen, emergency and infectious diseases isolation room . The isolation of the amoebas was performed in three culture media: non-nutrient agar inoculated with Escherichia coli, soy agar, and microculture in Giazzi-modified Pavlova's medium. The amoebas were identified according to morphological criteria. RESULTS: Amoebas of the genera Acanthamoeba and Naegleria were found in 45.5% of the samples, of which 41.6% were collected in the university hospital and 50% in the state hospital. Of all, 45.5% were positive for the genera Acanthamoeba and 3.8% for genera Naegleria. CONCLUSIONS: Potentially pathogenic free-living amoebas were seen in all sites of the two hospitals and Acanthamoeba was the most frequently isolated genera.OBJETIVO: Observar a ocorrência de amebas de vida livre dos gêneros Acanthamoeba e Naegleria em amostras de poeira coletadas em hospitais. MÉTODOS: Foram coletadas 132 amostras de poeira em dois hospitais do município de Presidente Prudente, São Paulo. Os locais da coleta foram: Unidade de Terapia Intensiva, Centro Cirúrgico, Isolamento de Moléstias Infecciosas, Berçário, Emergência e Cozinha. As amostras foram semeadas em três meios de cultura: meio de ágar não nutriente com Escherichia coli, meio de ágar infusão de soja e microcultivo em meio de Pavlova modificado por Giazzi. As amebas isoladas foram identificadas segundo critérios morfológicos. RESULTADOS: O índice geral de positividade para amebas de vida livre, potencialmente patogênicas, dos gêneros Acanthamoeba e Naegleria, foi de 45,5%, sendo positivas 41,6% das amostras de poeira coletadas no hospital universitário e 50% no hospital estadual. Obtiveram-se 45,5% de positividade do gênero Acanthamoeba e 3,8% para amebas do gênero Naegleria. CONCLUSÕES: As amebas de vida livre, potencialmente patogênicas, estavam presentes em todos os ambientes estudados dos dois hospitais, sendo que as espécies do gênero Acanthamoeba foram as isoladas com maior freqüência

Taxonomy, evolution, and biogeography of the rhodniini tribe (Hemiptera: Reduviidae)

The Triatominae subfamily includes 151 extant and three fossil species. Several species can transmit the protozoan parasite Trypanosoma cruzi, the causative agent of Chagas disease, significantly impacting public health in Latin American countries. The Triatominae can be classified into five tribes, of which the Rhodniini is very important because of its large vector capacity and wide geographical distribution. The Rhodniini tribe comprises 23 (without R. taquarussuensis) species and although several studies have addressed their taxonomy using morphological, morphometric, cytogenetic, and molecular techniques, their evolutionary relationships remain unclear, resulting in inconsistencies at the classification level. Conflicting hypotheses have been proposed regarding the origin, diversification, and identification of these species in Latin America, muddying our understanding of their dispersion and current geographic distribution. Clarifying these factors can help for the design of vector control strategies. The aim of this review is to depict the different approaches used for taxonomy of the Rhodniini and to shed light on their evolution and biogeography. © 2020 by the authors

Trypanosoma cruzi isolado de triatomíneos coletados na Bahia e Rio Grande do Sul

Collection of triatomines in domestic, peridomestic and sylvatic environments in states of Bahia and Rio Grande do Sul, Northeastern and Southern Brazil respectively, and isolation of Trypanosoma cruzi strains. METHODS First, the captured triatomines were identified using insect identification keys, then their intestinal content was examined by abdominal compression, and the samples containing trypanosomatid forms were inoculated in LIT medium and Swiss mice. RESULTS Six triatomine species were collected in cities in Bahia, namely Panstrongylus geniculatus (01), Triatoma melanocephala (11), T. lenti (94), T. pseudomaculata (02), T. sherlocki (26) and T. sordida (460), and two in cities in Rio Grande do Sul, namely T. circummaculata (11) and T. rubrovaria (115). Out of the specimens examined, T. cruzi was isolated from 28 triatomine divided into four different species: T. melanocephala (one), T. lenti (one), T. rubrovaria (16) and T. sordida (10). Their index of natural infection by T. cruzi was 6.4%. CONCLUSIONS The isolation of T. cruzi strains from triatomines found in domestic and peridomestic areas shows the potential risk of transmission of Chagas disease in the studied cities. The maintenance of those T. cruzi strains in laboratory is intended to promote studies that facilitate the understanding of the parasite-vector-host relationship482295302COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP23038.005285/2011-1213/08826-5Isolar cepas de Trypanosoma cruzi em triatomíneos capturados nos ambientes domiciliar, peridomiciliar e silvestre da Bahia e do Rio Grande do Sul. MÉTODOS Os triatomíneos capturados nos estados da Bahia e Rio Grande do Sul foram identificados por meio de chaves entomológicas. O conteúdo intestinal foi examinado por compressão abdominal e as amostras que continham formas de Trypanosomatidae foram inoculadas em meio de cultura Liver Infusion Tryptose e em camundongos Swiss. RESULTADOS Foram identificadas seis espécies de triatomíneos nas coletas realizadas em municípios do Estado da Bahia: Panstrongylus geniculatus (01), Triatoma melanocephala (11), T. lenti (94), T. pseudomaculata (02), T. sherlocki (26) e T. sordida (460), e duas no Estado do Rio Grande do Sul: T. circummaculata (11) e T. rubrovaria (115). Dos exemplares examinados, T. cruzi foi isolado de 28 triatomíneos pertencentes a quatro espécies: T. melanocephala (uma), T. lenti (uma), T. rubrovaria (16) e T. sordida (10). O índice de infecção natural de triatomíneos por T. cruzi foi de 6,4%. CONCLUSÕES O isolamento de cepas de T. cruzi em triatomíneos encontrados no intra e peridomicílio reflete o potencial risco de transmissão da doença de Chagas nos municípios estudado

Trypanosoma cruzi isolado de triatomíneos coletados na Bahia e Rio Grande do Sul

OBJECTIVE Collection of triatomines in domestic, peridomestic and sylvatic environments in states of Bahia and Rio Grande do Sul, Northeastern and Southern Brazil respectively, and isolation of Trypanosoma cruzi strains. METHODS First, the captured triatomines were identified using insect identification keys, then their intestinal content was examined by abdominal compression, and the samples containing trypanosomatid forms were inoculated in LIT medium and Swiss mice. RESULTS Six triatomine species were collected in cities in Bahia, namely Panstrongylus geniculatus (01), Triatoma melanocephala (11), T. lenti (94), T. pseudomaculata (02), T. sherlocki (26) and T. sordida (460), and two in cities in Rio Grande do Sul, namely T. circummaculata (11) and T. rubrovaria (115). Out of the specimens examined, T. cruzi was isolated from 28 triatomine divided into four different species: T. melanocephala (one), T. lenti (one), T. rubrovaria (16) and T. sordida (10). Their index of natural infection by T. cruzi was 6.4%. CONCLUSIONS The isolation of T. cruzi strains from triatomines found in domestic and peridomestic areas shows the potential risk of transmission of Chagas disease in the studied cities. The maintenance of those T. cruzi strains in laboratory is intended to promote studies that facilitate the understanding of the parasite-vector-host relationship.OBJETIVO Isolar cepas de Trypanosoma cruzi em triatomíneos capturados nos ambientes domiciliar, peridomiciliar e silvestre da Bahia e do Rio Grande do Sul. MÉTODOS Os triatomíneos capturados nos estados da Bahia e Rio Grande do Sul foram identificados por meio de chaves entomológicas. O conteúdo intestinal foi examinado por compressão abdominal e as amostras que continham formas de Trypanosomatidae foram inoculadas em meio de cultura Liver Infusion Tryptose e em camundongos Swiss. RESULTADOS Foram identificadas seis espécies de triatomíneos nas coletas realizadas em municípios do Estado da Bahia: Panstrongylus geniculatus (01), Triatoma melanocephala (11), T. lenti (94), T. pseudomaculata (02), T. sherlocki (26) e T. sordida (460), e duas no Estado do Rio Grande do Sul: T. circummaculata (11) e T. rubrovaria (115). Dos exemplares examinados, T. cruzi foi isolado de 28 triatomíneos pertencentes a quatro espécies: T. melanocephala (uma), T. lenti (uma), T. rubrovaria (16) e T. sordida (10). O índice de infecção natural de triatomíneos por T. cruzi foi de 6,4%. CONCLUSÕES O isolamento de cepas de T. cruzi em triatomíneos encontrados no intra e peridomicílio reflete o potencial risco de transmissão da doença de Chagas nos municípios estudados

An updated and illustrated dichotomous key for the Chagas disease vectors of Triatoma brasiliensis species complex and their epidemiologic importance

In the subfamily Triatominae, Triatoma exhibits the largest number of species, which are arranged in complexes. For the T. brasiliensis species complex, recent investigations based on results of geometric morphometrics combined with phylogeny have provided evidence that it should be composed of seven species: T. brasiliensis, T. bahiensis, T. juazeirensis, T. lenti, T. melanica, T. petrocchiae, and T. sherlocki, in which T. brasiliensis is divided in two subspecies: T. b. brasiliensis and T. b. macromelasoma. A taxonomic key is presented to identify each taxon. Among members of this complex, T. b. brasiliensis is the most important in an epidemiologic context, due to its high prevalence in natural infection by Trypanosoma cruzi combined with a pronounced adaptation to domiciliary habitats. However, some members may be currently invading and colonizing homes, a process known as domiciliation. Therefore, the key presented here may be potentially useful for researchers as well as those involved in vector control measures

Trypanosoma cruzi vectors in a periurban area of the Western Brazilian Amazon

The etiological agent of American trypanosomiasis is the protozoan Trypanosoma cruzi, typically transmitted by triatomines. The aim of this study was to investigate the triatomine fauna and trypanosomiasis infections in Acre State, Western Brazilian Amazon. Insect collection was performed by dissecting palm trees and installing traps. We found that T. cruzi infection rate was 24.5% and Rhodnius pictipes (57.1%) was the most abundant triatomine species. Health education as well as epidemiological and entomological surveillance are necessary to diagnose and prevent new cases of Chagas disease in the region

Taxonomical over splitting in the Rhodnius prolixus (Insecta: Hemiptera: Reduviidae) clade: Are R. taquarussuensis (da Rosa et al., 2017) and R. neglectus (Lent, 1954) the same species?

El uso de características sutiles como características de diagnóstico de especies en taxones con una gran similitud morfológica a veces falla en discriminar la variación intraespecífica de las diferencias interespecíficas, lo que lleva a una delimitación incorrecta de la especie. Una evaluación clara de los límites de las especies es particularmente relevante en los organismos vectores de enfermedades para comprender los procesos epidemiológicos y evolutivos que afectan la capacidad de transmisión. Aquí, evaluamos la validez del Rhodnius taquarussuensis recientemente descrito (da Rosa et al., 2017) utilizando cruces interespecíficos y marcadores moleculares. No detectamos diferencias en las tasas de eclosión en cruces interespecíficos entre R. taquarussuensis y R. negligencias (Lent, 1954). Además, los análisis de divergencia genética y delimitación de especies muestran que R. taquarussuensis no es un linaje independiente en el grupo R. prolixus. Estos resultados sugieren que R. taquarussuensis es una forma fenotípica de R. negligenciaus en lugar de una especie distinta. Nos gustaría enfatizar que se necesitan diferentes fuentes de evidencia para delimitar correctamente las especies. Consideramos que este es un paso importante en la comprensión de la propagación y transmisión vectorial de la enfermedad de Chagas.The use of subtle features as species diagnostic traits in taxa with high morphological similarity sometimes fails in discriminating intraspecific variation from interspecific differences, leading to an incorrect species delimitation. A clear assessment of species boundaries is particularly relevant in disease vector organisms in order to understand epidemiological and evolutionary processes that affect transmission capacity. Here, we assess the validity of the recently described Rhodnius taquarussuensis (da Rosa et al., 2017) using interspecific crosses and molecular markers. We did not detect differences in hatching rates in interspecific crosses between R. taquarussuensis and R. neglectus (Lent, 1954). Furthermore, genetic divergence and species delimitation analyses show that R. taquarussuensis is not an independent lineage in the R. prolixus group. These results suggest that R. taquarussuensis is a phenotypic form of R. neglectus instead of a distinct species. We would like to stress that different sources of evidence are needed to correctly delimit species. We consider this is an important step in understanding vectorial Chagas disease spread and transmission

Taxonomical over splitting in the Rhodnius prolixus (Insecta: Hemiptera: Reduviidae) clade: Are R. Taquarussuensis (da Rosa et al., 2017) and R. Neglectus (Lent, 1954) the same species?

El uso de características sutiles como características de diagnóstico de especies en taxones con una gran similitud morfológica a veces falla en discriminar la variación intraespecífica de las diferencias interespecíficas, lo que lleva a una delimitación incorrecta de la especie. Una evaluación clara de los límites de las especies es particularmente relevante en los organismos vectores de enfermedades para comprender los procesos epidemiológicos y evolutivos que afectan la capacidad de transmisión. Aquí, evaluamos la validez del Rhodnius taquarussuensis recientemente descrito (da Rosa et al., 2017) utilizando cruces interespecíficos y marcadores moleculares. No detectamos diferencias en las tasas de eclosión en cruces interespecíficos entre R. taquarussuensis y R. negligencias (Lent, 1954). Además, los análisis de divergencia genética y delimitación de especies muestran que R. taquarussuensis no es un linaje independiente en el grupo R. prolixus. Estos resultados sugieren que R. taquarussuensis es una forma fenotípica de R. negligenciaus en lugar de una especie distinta. Nos gustaría enfatizar que se necesitan diferentes fuentes de evidencia para delimitar correctamente las especies. Consideramos que este es un paso importante en la comprensión de la propagación y transmisión vectorial de la enfermedad de Chagas.The use of subtle features as species diagnostic traits in taxa with high morphological similarity sometimes fails in discriminating intraspecific variation from interspecific differences, leading to an incorrect species delimitation. A clear assessment of species boundaries is particularly relevant in disease vector organisms in order to understand epidemiological and evolutionary processes that affect transmission capacity. Here, we assess the validity of the recently described Rhodnius taquarussuensis (da Rosa et al., 2017) using interspecific crosses and molecular markers. We did not detect differences in hatching rates in interspecific crosses between R. taquarussuensis and R. neglectus (Lent, 1954). Furthermore, genetic divergence and species delimitation analyses show that R. taquarussuensis is not an independent lineage in the R. prolixus group. These results suggest that R. taquarussuensis is a phenotypic form of R. neglectus instead of a distinct species. We would like to stress that different sources of evidence are needed to correctly delimit species. We consider this is an important step in understanding vectorial Chagas disease spread and transmission. © 2019 Nascimento et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited