Chemical Composition and In Vitro Antioxidant, Cytotoxic, Antimicrobial, and Larvicidal Activities of the Essential Oil of Mentha piperita L. (Lamiaceae).

The essential oil was obtained by hydrodistillation and the identification and quantification of components were achieved with the use of GC-MS analysis. The antioxidant activity was evaluated by the method of sequestration of DPPH. Essential oils were used for study the cytotoxic front larvae of Artemia salina. In the evaluation of the antimicrobial activity of essential oils, we employed the disk-diffusion method. The potential larvicide in mosquito larvae of the third stage of development of Aedes aegypti to different concentrations of essential oils was evaluated. The major compounds found in the essential oils of M. piperita were linalool (51.8%) and epoxyocimene (19.3%). The percentage of antioxidant activity was 79.9 ± 1.6%. The essential oil showed LC50 = 414.6 µg/mL front of A. saline and is considered highly toxic. It shows sensitivity and halos significant inhibition against E. coli. The essential possessed partial larvicidal efficiency against A. aegypti.

Larvicidal and Adulticidal Activity of Essential Oils from Four Cuban Plants against Three Mosquito Vector Species.

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.

Ants (Hymenoptera: Formicidae) as Potential Mechanical Vectors of Pathogenic Bacteria in a Public Hospital in the Eastern Amazon, Brazil.

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.

Nano-emulsification Enhances the Larvicidal Potential of the Essential Oil of Siparuna guianensis (Laurales: Siparunaceae) Against Aedes (Stegomyia) aegypti (Diptera: Culicidae).

Siparuna guianensis (Laurales: Siparunaceae) has a terpene-rich essential oil with great potential for larvicides. The poor water miscibility of their compounds makes nano-emulsions of great interest for novel bioactive systems, including for control of Aedes aegypti (Diptera: Culicidae). This species is adapted to urban environments with important role in the epidemiology of some arboviruses such as dengue, chikungunya fever, zika, and urban yellow fever. The aim of the present study was to evaluate the feasibility of nano-emulsification to affect Ae. aegypti larvae. An optimal system was achieved by using a nonionic single surfactant, highlighted by its satisfactory size distribution profile. Moreover, improved larvicidal activity in comparison to bulk essential oil can be observed for the nano-emulsions. The estimated LC50 and LC90 values after 24 h of treatment of larvae with the essential oil were, respectively, 86.5232 and 134.814 µg/ml, while the estimated LC50 and LC90 value after treatment with the nano-emulsion were 24.7572 and 75.2452 µg/ml, respectively. The utilization of a simple technique to produce a fine nano-emulsion opens perspective for further integrative practices of mosquito control and giving value to this Amazon plant species may encourage its sustainable use and contribute to conservation policies.

Ecological aspects and molecular detection of Leishmania DNA (Kinetoplastida: Trypanosomatidae) in phlebotomine sand flies (Diptera: Psychodidae) from a rural settlement in the Eastern Amazon, Brazil

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.

New records of dragonflies and damselflies (Insecta: Odonata) from Amapá state, Brazil / Libélulas e donzelinhas (Insecta: Odonata) novos registros para o estado do Amapá, Brasil

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.

Composition, abundance and aspects of temporal variation in the distribution of Anopheles species in an area of Eastern Amazonia.

INTRODUCTION: The diverse and complex environmental conditions of the Amazon Basin favor the breeding and development of Anopheles species. This study aimed to describe the composition, abundance and temporal frequency of Anopheles species and to correlate these factors with precipitation, temperature and relative humidity. METHODS: The study was conducted in the District of Coração, State of Amapá, Brazil. Samples were collected monthly during three consecutive nights, from 6:00 PM to 10:00 PM, from December 2010 to November 2011. In addition, four 12-hour collections (i.e., 6:00 PM to 6:00 AM) were performed during this period. RESULTS: A total of 1,230 Anopheles specimens were collected. In the monthly collections, Anopheles darlingi was the predominant species, followed by An. braziliensis and An. albitarsis s.l., whereas An. darlingi, An. peryassui and An. braziliensis were the most frequent species collected in the 12-hour collections. The greatest number of anophelines was collected in September (the dry season). The highest frequency of anophelines was observed for An. darlingi during September, when there were the least rainfalls of the year, along with lower relative humidity and higher temperatures. There was little variation in the abundance of this species in other months, with the exception of slight increases in February, July and August. CONCLUSIONS: The major malaria vectors, An. darlingi and An. albitarsis s.l. (likely An. marajoara), were the most abundant species collected in the study area. Consequently, prevention and control measures should be taken to prevent malaria outbreaks in the District of Coração.

Nanosuspension of quercetin: preparation, characterization and effects against Aedes aegypti larvae

Abstract Aedes aegypti (Diptera: Culicidae) is the main vector of some neglected diseases, including dengue. It is very important to develop formulations that increase effectiveness of vector control with low toxicity. Quercetin is a plant-derived flavonoid that modulates the development of some insects. The low water solubility of quercetin impairs the development of water-dispersible commercial products. To circumvent this problem, the preparation of nanoformulations is considered promising. Thus, this study aimed to evaluate the effect of bulk and quercetin nanosuspension against A. aegypti larvae and also to investigate their ecotoxicity. Quercetin nanosuspension was produced by a solvent displacement method followed by solvent evaporation and was maintained in two different temperatures (4 and 25 ºC). Its size distribution and zeta potential were monitored along 30 days. The influence of quercetin nanosuspension and bulk-quercetin was investigated at various concentrations against A. aegypti and the green algae Chlorella vulgaris. The quercetin nanosuspension presented higher stability at 4 ºC and negative zeta potential values. Quercetin nanosuspension and bulk-quercetin adversely affected the larvae development, especially at the highest concentrations. Larvae mortality was between 44% and 100% (48 h) for quercetin nanosuspension at 100 and 500 ppm, respectively. The bulk-quercetin induced around 50% mortality regardless the concentration used at this same time-period. Absence of emerging mosquitoes from water was observed on the survival larvae of all the treated groups. Quercetin nanosuspension was less toxic than bulk-quercetin against C. vulgaris, especially at higher concentrations. These data indicate that quercetin nanosuspension may represent a potential larvicide for A. aegypti control, once they induced larvae death and inhibited the survival ones to emerge from water. In addition, it did not demonstrated ecotoxicity against a non-target organism, highlighting its better properties, when compared to the bulk-quercetin.

Entomological survey of phlebotominae sand flies (diptera: psychodidae) and vector species in the tegumentary leishmaniasis endemic area in eastern brazilian Amazon, Amapá state / Levantamento entomológico de flebotomíneos (Diptera: Psychodidae) e espécies vetoras na área endêmica de leishmaniose tegumentar na Amazônia oriental brasileira, Estado do Amapá

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.

Composition, abundance and aspects of temporal variation in the distribution of Anopheles species in an area of Eastern Amazonia

Introduction The diverse and complex environmental conditions of the Amazon Basin favor the breeding and development of Anopheles species. This study aimed to describe the composition, abundance and temporal frequency of Anopheles species and to correlate these factors with precipitation, temperature and relative humidity. Methods The study was conducted in the District of Coração, State of Amapá, Brazil. Samples were collected monthly during three consecutive nights, from 6:00 PM to 10:00 PM, from December 2010 to November 2011. In addition, four 12-hour collections (i.e., 6:00 PM to 6:00 AM) were performed during this period. Results A total of 1,230 Anopheles specimens were collected. In the monthly collections, Anopheles darlingi was the predominant species, followed by An. braziliensis and An. albitarsis s.l., whereas An. darlingi, An. peryassui and An. braziliensis were the most frequent species collected in the 12-hour collections. The greatest number of anophelines was collected in September (the dry season). The highest frequency of anophelines was observed for An. darlingi during September, when there were the least rainfalls of the year, along with lower relative humidity and higher temperatures. There was little variation in the abundance of this species in other months, with the exception of slight increases in February, July and August. Conclusions The major malaria vectors, An. darlingi and An. albitarsis s.l. (likely An. marajoara), were the most abundant species collected in the study area. Consequently, prevention and control measures should be taken to prevent malaria outbreaks in the District of Coração. .