RESUMO

Mosquitoes are one of the main vectors of many important diseases and their degree of resistance to chemical insecticides has increased. Nowadays, it has become crucial to identify novel plant larvicides with an eco-friendly impact. The components of essential oils from Croton linearis Jacq. (EO-Cl), Lantana involucrata L. (EO-Li), Ocimum sanctum var. cubensis M. Gómez. (EO-Os), and Zanthoxylum pistaciifolium Griseb. (syn. Zanthoxylum flavum subsp. pistaciifolium (Griseb.) Reynel (EO-Zp) were determined using gas chromatography-mass spectrometry (GC-MS) analysis. Larvicidal and adulticidal bioassays against Aedes aegypti, Anopheles albitarsis and Culex quinquefasciatus, were performed according to the World Health Organization standard methods. A high diversity of compounds was identified in the four oils, with a total of 152 compounds (33-70 components). EO-Cl, EO-Li, and EO-Os were classified as active against both insect forms, larvae and adults. Lantana involucrata showed the best results, with LC50 values from 33.8 to 41.7 mg/L. In most of the cases, it was not possible to associate the main compounds with the measured activity, supporting the hypothesis about probable synergistic interactions among major and minor compounds. The results indicate EO-Cl, EO-Os, and EO-Li as good eco-friendly insecticides with potential.

RESUMO

Fatal poisonings with diazinon may occur both accidentally or intentionally in suicide cases. Forensic entomotoxicology can aid in understanding these deaths by detecting and analyzing the interference of toxic substances in the biology of necrophagous insects. Hence, this study sought to evaluate diazinon's effect on the composition and succession of calliphorid species in the tropical savannas of the Amazon. Nine rabbit carcasses were divided into three groups: one control and two diazinon treatments (100 mg/kg and 300 mg/kg); each group had three replicates. Three fragments of the Amazon tropical savanna were selected for the experiments. Daily collections of adult and immature calliphorids were performed. Five decomposition stages were observed: fresh, bloated, active decay co-occurring, advanced decay, and dry. Eight species of Calliphoridae were identified among the collected adults: Chloroprocta idioidea (0.1%), Chrysomya albiceps (58.3%), Chrysomya megacephala (14.2%), Chrysomya putoria (2.6%), Cochliomyia hominivorax (1.3%), Cochliomyia macellaria (0.5%), Lucilia eximia (19.8%), and Paralucilia paraensis (3.3%). The adult specimens in the control group with the highest abundance were observed only from the advanced decay stage onward. In the dry stage, abundance was higher in control than in treated carcasses. From the sampled 941 Calliphorid immatures, three species were identified: C. albiceps (76,3%), C. putoria (1%), and L. eximia (22,7). The number of immatures was higher in control than in treated carcasses. Therefore, diazinon interferes with the putrefaction timeframe in carcasses, slowing the decomposition stages and affecting their colonization by immature forms of Calliphoridae.

Assuntos

RESUMO

American tegumentary leishmaniasis is an endemic that has increased considerably in recent decades in the Amazon region, sand flies are the vectors of the transmission of the protozoan that causes leishmaniasis, so the objective of this study was to carry out a survey of the diversity of species and the presence of Leishmania DNA in vectors circulating in three endemic counties for tegumentary leishmaniasis in the eastern Brazilian Amazon (Amapá state, Brazil). Using CDC light traps, a total of 10,773 specimens were collected between February 2019 and February 2020, representing 64 species in 15 genera. The vector specie Nyssomyia umbratilis Ward and Frahia, 1977 was the predominant species (13.20% of the total), being collected in all three counties, followed by Trichopygomyia trichopyga Floch & Abonnenc, 1945 (11.41%), Trichophoromyia ubiquitalis Mangabeira,1942 (9.47%) and Nyssomyia anduzei Rozeboom, 1942 (7.61%). For the identification of Leishmania DNA, 775 pools of unengorged females were used, of which 5 tested positive, 2 of Nyssomya umbratilis Ward & Fraiha,1977, 1 of Nyssomyia anduzei and 2 of Psychodopygus davisi Root,1934, demonstrating a natural total infection rate of 0.64%. This study increases the knowledge of vector diversity, as well as identifying Leishmania spp. in circulation in the eastern region of the Amazon.

A leishmaniose tegumentar americana é uma endemia que aumentou consideravelmente nas últimas décadas na região amazônica, os flebotomíneos são os vetores da transmissão do protozoário causador da leishmaniose, portanto o objetivo deste estudo foi realizar um levantamento da diversidade de espécies e a presença de DNA de Leishmania em vetores que circulam em três municípios endêmicos de leishmaniose tegumentar na Amazônia oriental brasileira (Amapá, Brasil). Usando armadilhas luminosas do tipo CDC, um total de 10.773 espécimes foram coletados entre fevereiro de 2019 e fevereiro de 2020, representando 64 espécies em 15 gêneros. As espécie vetoras - singular Nyssomyia umbratilis Ward e Frahia 1977 foram as espécies predominantes (13,20% do total), sendo coletadas nos três municípios, seguido por Trichopygomyia trichopyga Floch & Abonnenc, 1945 (11,41%), Trichophoromyia ubiquitalis Mangabeira, 1942 (9,47%) e Nyssomyia anduzei Rozeboom, 1942 (7,61%). Para a identificação do DNA de Leishmania, foram utilizados 775 pools de fêmeas não ingurgitadas, dos quais 5 foram positivos, 2 de Nyssomya umbratilis Ward & Fraiha, 1977, 1 de Nyssomyia anduzei e 2 de Psychodopygus davisi Root, 1934, demonstrando uma taxa de infecção total de 0,64%. Este estudo aumenta o conhecimento da diversidade de vetores, bem como a identificação das espécies de Leishmania spp. em circulação na região oriental da Amazônia.

RESUMO

To analyze the application of the metagenomics method in the identification of viral infectious agents that lead to diarrhea outbreaks. This study is a systematic review, which looked for publications on the following platforms: PubMed, Scientific Electronic Library Online (SciELO), LILACS and CAPES periodicals, conducted according to the PRISMA methodology, investigating in the literary composition studies related to metagenomics applied in the identification of viral infectious agents, which lead to diarrhea in humans. 1198 publications were identified. Of these, after analyzes and exclusions at different stages, 18 studies remained, which directly corresponded to the theme. Diarrhea was presented as a universal health concern. Despite the emergence of vaccines, cases of diarrhea remain persistent in poor populations. In this context, metagenomics emerges as a primary tool in detecting enteric viruses and identifying new viruses, revolutionizing health diagnoses, knowledge of viral diversity, and health surveillance, contributing to the correct etiology of infectious agents that would never be identified by conventional methods. The 18 articles studied point to advances in research in viral metagenomics of diarrheal samples, contributing to the discernment of diarrhea outbreaks, and properly associating with their etiological agents, they are presented in an innovative way for studies on the understanding of viral diversity.

Assuntos

RESUMO

ABSTRACT Notifications concerning American tegumentary leishmaniasis (ATL) are increasing in the northern areas of Brazil, particularly due to the ongoing increase in human settlements inside the Amazon Forest. Notwithstanding the economical and sanitary importance of the ATL, the ecological aspects of its potential vectors, the Phlebotomine sand flies (Diptera: Psychodidae), remains largely neglected. This study aimed to investigate the diversity of the phlebotomine fauna as well as the detection of Leishmania DNA in these insects in the rural settlement Perimetral Norte, in the state of Amapá, eastern region of the Amazon, endemic region for tegumentary leishmaniasis. Sand flies were collected bimonthly from February 2018 to February 2019, using CDC light traps exposed for three consecutive nights in 10 houses of settlement residents. DNA extraction and multiplex PCR were performed to detect trypanosomatids. A total of 3,946 sandflies belonging to 37 species were collected. The most abundant species were Ty. trichopyga (Floch & Abonnenc, 1945) (21.9%) and Mi. rorotaensis (Floch & Abonnenc, 1944) (16.9%). A total of 36 positive pools were found with Leishmania DNA (Kinetoplastida: Trypanosomatidae), representing 17.9% of the total pools tested (201), those with the highest Minimum infection rates were Mg. migonei (França, 1920) and Lu. gomezi (Nitzulescu, 1931), Leishmania DNA was also detected in Bi. flaviscutellata (Mangabeira, 1942), Ny. umbratilis (Ward & Fraiha, 1977), Ny. anduzei (Roseboom, 1942) and Ny. antunesi (Coutinho, 1939). These data confirm the probable participation of these four species in the tegumentary leishmaniasis cycle in the eastern Amazon.

RESUMO

Abstract: The Odonata Order comprises one of the largest groups of aquatic insects, 7,000 species are described worldwide, with approximately 860 species registered in Brazil, around 14% of the global fauna known to date. However, there are still great gaps in the knowledge of Odonata fauna in many areas of Brazil. This study aims to present the results of the survey of Odonata species sampled in three counties in the state of Amapá. The state is located in the north of the country, inserted in the Amazon Biome. Odonata were caught between January and December 2018, with 472 specimens being sampled, belonging to seven families, 36 genera and 53 species. In total, 27 of the species found during the study correspond to new records for the state of Amapá. Due to the lack of information on the diversity of the Odonata order in Amapá, the list of species presented should serve as input for new studies contributing to the knowledge of the order in the state.

Resumo: A ordem Odonata compreende um dos maiores grupos de insetos aquáticos, mundialmente são descritas 7.000 espécies, sendo que, para o Brasil estão registradas aproximadamente 860 espécies, algo em torno de 14% da fauna global conhecida até o momento. No entanto, ainda existem grandes lacunas no conhecimento da odonatofauna em muitas áreas do Brasil. Este estudo tem como objetivo apresentar o resultado do levantamento de espécies de Odonata amostradas em três municípios do estado Amapá. O estado se encontra na região norte do país, inserido no Bioma amazônico. As capturas de Odonata foram realizadas entre os meses de janeiro e dezembro de 2018, sendo amostrados 472 espécimes pertencentes a sete famílias, 36 gêneros e 53 espécies. No total, 27 das espécies encontradas durante o estudo correspondem a novos registros para o estado do Amapá. Devido à falta de informação sobre a diversidade da ordem Odonata no Amapá, a lista de espécies apresentada deve servir de aporte para novos estudos contribuindo com o conhecimento da ordem no estado.

RESUMO

Viruses are the most diverse and abundant microorganisms on earth, highly adaptive to a wide range of hosts. Viral diversity within invertebrate hosts has gained notoriety in recent years in public health as several such viruses have been of medical importance. Aedes aegypti serves as a vector for several viruses that have caused epidemics within the last year throughout Brazil; including Dengue, Zika and Chikungunya. This study aimed to identify new viral agents within Aedes aegypti mosquito in a city of the Amazonian region, where it is highly endemic. Metagenomic investigation was performed on 60 mosquito pools and viral RNA sequences present in their microbiota were characterized using genomic and phylogenetic tools. In total, we identified five putative novel virus species related to the Sobemovirus genus, Iflavirus genus and Permutatetraviridae family. These findings indicate a diverse taxonomy of viruses present in the mosquito microbiota of the Amazon, the region with the greatest invertebrate diversity in the world.

Assuntos

RESUMO

Studies related to ants found in hospital environments have aroused interest in their role as mechanical vectors of pathogenic microorganisms. The objective of the current research was to determine the species composition and bacterial contamination of ant species found in a public hospital in the eastern Amazonian region. Ants were captured using bait containing honey and sterilized sardines in 15 locations within the Macapá Emergency Hospital, Amapá. Ants were identified morphologically using specific keys. Bacteria were first inoculed in a Brain Heart Infusion broth and then plated on 5% Agar with blood or MacConkey media. Bacterial species were identified through biochemical procedures. In total, 9,687 ants were collected, with 69.8% from the dry season and 30.2% from the rainy season. Nine species of ants were identified belonging to three subfamilies: the Monomorium pharaonis (Linnaeus 1758) being the most common, comprising 39.2% of the total specimens. Only one ant species was found in each bait, facilitating microbiological analyses. In total, 92 bacteria isolates were identified comprising 12 species. Pseudomonas aeruginosa Schroeter 1872 (Pseudomonadales: Pseudomonadaceae) was pathogenic bacteria, most frequently isolated, comprising 10.9% of the positive samples. The most contaminated ant in the study was M. pharaonis with 38.3%. It was the dominant ant species in this hospital environment. Its wide prevalence, forage day and night of this vector in hospital facilitated bacterial contamination. The presence of bacteria on ants may be associated with the dissemination of pathogens which cause hospital infections, making pest control a necessity in these institutions.

Assuntos

RESUMO

Aedes aegypti is associated with epidemic diseases in Brazil, such as urban yellow fever, dengue, and more recently, chikungunya and Zika viruses infections. More information about Ae. aegypti infestation is fundamental to virological surveillance in order to ensure the effectiveness of control measures in use. Thus, the present study aims to identify and compare infestation and infectivity of Ae. aegypti females in Macapa city, Amapa State (Amazon region), Brazil, between the epidemiological weeks 2017/02 and 2018/20. A total number of 303 Ae. aegypti females were collected at 21 fixed collection points, 171 at the 10 collection points in the Marabaixo neighborhood and 132 at the 11 collection points in the Central neighborhood. Among the collected samples, only two were positive for dengue virus, with a 2.08% (2/96 pools) infectivity rate for Marabaixo. The difference between the medians of Ae. aegypti females captured in Central and Marabaixo sites was not statistically significant. The findings indicate similar mosquito infestation levels between the neighborhoods, and a low-level of mosquito infectivity, although dengue virus was found only in Marabaixo. Virological surveillance of Ae. aegypti was important to identify sites of infection and determine possible routes of transmission to enable health surveillance teams to adopt preventive strategies where infected mosquitoes are present and act faster.

Assuntos

RESUMO

In this study, the essential oil (EO) from leaves of Croton linearis Jacq was extracted and characterized by GC/MS. The EO hydrophilic-lipophilic balance required (rHLB) for nanoemulsion (NE) development was determined by the Griffin' method. For evaluating the larvicidal effect against Aedes aegypti, the preparation process of NE was optimized, using a central composite design. It was also evaluated the possible toxic effect of NE in nontarget species. The leaves of C. linearis contain 1.50% of EO, enclosing 61 volatile compounds, mainly eucalyptol (26.66%). The best surfactant, oil:water ratio (4.5-5.0-91.5; % w:w:w), allows to achieve the optimal NE, using a stirring speed of 800 rpm, the addition rate of 0.5 ml/min, and a stirring time of 30 min. NE (with particle size = 163 nm) showed a larvicide effect (LC50 = 17.86 µg/mL) more potent than the whole EO (LC50 = 64.24 µg/mL). NE showed neither hemolytic effect nor cytotoxicity, and it was classified as a nontoxic product, according to the OECD class toxicity test (IC50 > 2000 mg/kg). This product arises in a new green bio-larvicide that could be used for mosquito control.

Assuntos