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PURPOSE: The flea Ctenocephalides felis (Siphonaptera: Pulicidae), parasitizes dogs and cats globally, acting as a vector for various pathogens affecting both animals and humans. Growing interest in environmentally friendly, plant-based products prompted this study. The aim of the study was to determine the chemical composition of essential oils (EOs) from Copaifera reticulata, Citrus paradisi, Lavandula hybrida and Salvia sclarea, assessing their insecticidal and repellent properties, determining lethal concentrations (LC50 and LC90), and evaluating residual efficacy in vitro against Ctenocephalides felis felis. METHODS: Gas Chromatography with Flame Ionization Detector analyzed EO composition. In vitro tests involved preparing EO solutions at various concentrations. Ten specimens from each life stage (egg, larva, pupa, adult) were used for insecticidal activity assessment. Adulticidal activity was assessed using 10 cm2 filter paper strip, each treated with 0.200 mL of the test solution. Immature stages activities were evaluated using 23.76 cm2 discs of the same filter paper, each treated with 0.470 mL of the test solution. Mortality percentage was calculated using (number of dead insects × 100) / number of incubated insects. Probit analysis calculated LC50 values with a 95% confidence interval. RESULTS: Major EO constituents were ß-caryophyllene (EOCR), linalool (EOLH), linalyl acetate (EOSS), and limonene (EOCP). LC50 values were obtained for all stages except for the essential oil of C. paradisi. All oils showed repellent activity at 800 µg/cm2. OECR exhibited greater residual efficacy. CONCLUSION: Each EO demonstrated superior insecticidal activity against specific C. felis felis stages.
Assuntos
Ctenocephalides , Repelentes de Insetos , Inseticidas , Óleos Voláteis , Salvia , Animais , Óleos Voláteis/farmacologia , Óleos Voláteis/química , Salvia/química , Repelentes de Insetos/farmacologia , Repelentes de Insetos/química , Inseticidas/farmacologia , Inseticidas/química , Ctenocephalides/efeitos dos fármacos , Fabaceae/química , Lavandula/química , Larva/efeitos dos fármacos , Pupa/efeitos dos fármacos , Citrus/química , Monoterpenos Acíclicos/farmacologia , Monoterpenos/farmacologia , Monoterpenos/química , Óleos de Plantas/farmacologia , Óleos de Plantas/química , Dose Letal MedianaRESUMO
Stomoxys calcitrans L. (Diptera: Muscidae), the stable fly, is a hematophagous insect of great veterinary importance, because it is a mechanical vector of diverse pathogens in livestock. The saliva of blood-feeding insects presents important pharmacologically active molecules that impair blood clotting, promote vasodilation and modulate the host immune system response, crucial processes for successful feeding. These properties also enable pathogens' transmission. In the present work, we describe an efficient protocol to dissect S. calcitrans salivary glands, their morphological characteristics and lipid profile. The mean length of the tubular gland is 3.23 mm with a bulbous posterior end and a narrow anterior end. Histological analysis revealed a monolayer of large polygonal epithelial cells with voluminous nuclei and high lipid content in their cytoplasm. Ultrastructural analysis showed that the epithelium is rich in mitochondria, free ribosomes, Golgi complex cisternae, presenting a great extension of rough endoplasmic reticulum that contains an electron-dense material. Lipid analysis by thin-layer chromatography showed that neutral fatty acids and phosphatidylcholine are predominant in the fly salivary glands. Lysophosphatidylcholine, an important signalling biomolecule involved in different metabolic processes, including host's immunomodulation and pathogens proliferation and differentiation, is also present.
Stomoxys calcitrans L. (Diptera: Muscidae), a moscadosestábulos, é um inseto hematófago de grande importância veterinária, uma vez que é vetor mecânico de diversos patógenos que infectam animais da pecuária. A saliva de insetos que se alimentam de sangue apresenta importantes moléculas farmacologicamente ativas que impedem coagulação sanguínea, promovem vasodilatação e modulam o sistema imune do hospedeiro, processos cruciais para uma alimentação bem sucedida. Tais propriedades também permitem a transmissão de patógenos. No presente trabalho, nós descrevemos um protocolo eficiente para dissecar as glândulas salivares de S. calcitrans, suas características morfológicas e perfil lipídico. O comprimento médio da glândula tubular é 3.23 mm com uma porção posterior bulbosa e porção anterior estreita. Análises histológicas revelaram uma monocamada de células epiteliais largas e poligonais com núcleos volumosos e alto conteúdo lipídico em seus citoplasmas. Análises ultraestruturais mostraram um epitélio rico em mitocôndria, ribossomos livres, cisternas do complexo de Golgi, apresentando uma grande extensão de retículo endoplasmático que contém um material eletrodenso. A análise lipídica mostrou que ácidos graxos neutros e fosfatidilcolina predominam nas glândulas salivares da mosca. Lisofosfatidilcolina, uma importante biomolécula sinalizadora envolvida em diferentes processos metabólicos, incluindo imunomodulação do hospedeiro e proliferação e diferenciação de patógenos, também se encontra presente.
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Mosquitoes can transmit several pathogenic viruses to humans, but their natural viral community is also composed of a myriad of other viruses such as insect-specific viruses (ISVs) and those that infect symbiotic microorganisms. Besides a growing number of studies investigating the mosquito virome, the majority are focused on few urban species, and relatively little is known about the virome of sylvatic mosquitoes, particularly in high biodiverse biomes such as the Brazilian biomes. Here, we characterized the RNA virome of 10 sylvatic mosquito species from Atlantic forest remains at a sylvatic-urban interface in Northeast Brazil employing a metatranscriptomic approach. A total of 16 viral families were detected. The phylogenetic reconstructions of 14 viral families revealed that the majority of the sequences are putative ISVs. The phylogenetic positioning and, in most cases, the association with a high RNA-dependent RNA polymerase amino acid divergence from other known viruses suggests that the viruses characterized here represent at least 34 new viral species. Therefore, the sylvatic mosquito viral community is predominantly composed of highly divergent viruses highlighting the limited knowledge we still have about the natural virome of mosquitoes in general. Moreover, we found that none of the viruses recovered were shared between the species investigated, and only one showed high identity to a virus detected in a mosquito sampled in Peru, South America. These findings add further in-depth understanding about the interactions and coevolution between mosquitoes and viruses in natural environments. IMPORTANCE: Mosquitoes are medically important insects as they transmit pathogenic viruses to humans and animals during blood feeding. However, their natural microbiota is also composed of a diverse set of viruses that cause no harm to the insect and other hosts, such as insect-specific viruses. In this study, we characterized the RNA virome of sylvatic mosquitoes from Northeast Brazil using unbiased metatranscriptomic sequencing and in-depth bioinformatic approaches. Our analysis revealed that these mosquitoes species harbor a diverse set of highly divergent viruses, and the majority comprises new viral species. Our findings revealed many new virus lineages characterized for the first time broadening our understanding about the natural interaction between mosquitoes and viruses. Finally, it also provided several complete genomes that warrant further assessment for mosquito and vertebrate host pathogenicity and their potential interference with pathogenic arboviruses.
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Culicidae , Filogenia , Viroma , Animais , Brasil , Viroma/genética , Culicidae/virologia , Mosquitos Vetores/virologia , Genoma Viral , RNA Viral/genética , Vírus de Insetos/genética , Vírus de Insetos/classificação , Vírus de Insetos/isolamento & purificação , Vírus de RNA/genética , Vírus de RNA/classificação , Vírus de RNA/isolamento & purificaçãoRESUMO
The Orthoflavivirus ilheusense (ILHV) is an arbovirus that was first isolated in Brazil in 1944 during an epidemiologic investigation of yellow fever. Is a member of the Flaviviridae family and it belongs to the antigenic complex of the Ntaya virus group. Psorophora ferox is the primary vector of ILHV and this study presents the isolation and phylogenetic analysis of ILHV in a pool of Ps. ferox collected in the state of Goiás in 2021. Viral isolation tests were performed on Vero cells and C6/36 clones. The indirect immunofluorescence test (IFI) was used to confirm the positivity of the sample. The positive sample underwent RT-qPCR, sequencing, and phylogenetic analysis. This is the first report of ILHV circulation in this municipality and presented close relationship between this isolate and another ILHV isolate collected in the city of Belém (PA).
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Culicidae , Filogenia , Animais , Brasil , Células Vero , Culicidae/virologia , Chlorocebus aethiops , Flavivirus/genética , Flavivirus/isolamento & purificação , Flavivirus/classificação , Mosquitos Vetores/virologiaRESUMO
Leishmaniasis is a group of diseases caused by protozoa of the genus Leishmania and is transmitted by the bite female sand fly. The present work is characterized as a descriptive study in two areas: a forest area located in the Parque Estadual do Rio Doce, and another urban area located in the municipality of Timóteo-MG, with the objective of identifying the presence of Leishmania spp. and the blood source of the collected female sand flies. Part of the females were obtained from the Parque Estadual do Rio Doce, and part was collected using 19 ligth traps distributed in residences of Timóteo. For molecular studies of Leishmania spp. DNA, the ITS1 gene was used, and in the search for blood source, the CytB gene was used and positive samples were sequenced. The study demonstrated that there are at least three species of Leishmania circulating in the study areas: Leishmania (Viannia) braziliensis, Leishmania (Leishmania) amazonensis, and Leishmania (V.) guyanensis. Nyssomyia whitmani was the predominant sand fly species in the urban area of Timóteo with a positive diagnosis for the presence of Leishmania braziliensis DNA. We found the presence of blood from Gallus gallus (Chicken) and Sus scrofa (Pig) in sand flies. The present study demonstrates that Leishmania braziliensis is the main agent of cutaneous leishmaniasis in the study area, with the effective participation of Nyssomyia whitmani as the vector and both Gallus gallus and Sus scrofa acting as a food source for female sand flies, and helping maintaining the sand fly life.
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BACKGROUND: Mexico has experienced a significant reduction in malaria cases over the past two decades. Certification of localities as malaria-free areas (MFAs) has been proposed as a steppingstone before elimination is achieved throughout the country. The Mexican state of Quintana Roo is a candidate for MFA certification. Monitoring the status of insecticide susceptibility of major vectors is crucial for MFA certification. This study describes the susceptibility status of Anopheles albimanus, main malaria vector, from historically important malaria foci in Quintana Roo, using both phenotypic and genotypic approaches. METHODS: Adult mosquito collections were carried out at three localities: Palmar (Municipality of Othon P. Blanco), Buenavista (Bacalar) and Puerto Morelos (Puerto Morelos). Outdoor human-landing catches were performed by pairs of trained staff from 18:00 to 22:00 during 3-night periods at each locality during the rainy season of 2022. Wild-caught female mosquitoes were exposed to diagnostic doses of deltamethrin, permethrin, malathion, pirimiphos-methyl or bendiocarb using CDC bottle bioassays. Mortality was registered at the diagnostic time and recovery was assessed 24 h after exposure. Molecular analyses targeting the Voltage-Gated Sodium Channel (vgsc) gene and acetylcholinesterase (ace-1) gene were used to screen for target site polymorphisms. An SNP analysis was carried out to identify mutations at position 995 in the vgsc gene and at position 280 in the ace-1 gene. RESULTS: A total of 2828 anophelines were collected. The main species identified were Anopheles albimanus (82%) and Anopheles vestitipennis (16%). Mortalities in the CDC bottle bioassay ranged from 99% to 100% for all the insecticides and mosquito species. Sequence analysis was performed on 35 An. albimanus across the three localities; of those, 25 were analysed for vgsc and 10 for ace-1 mutations. All individuals showed wild type alleles. CONCLUSION: The results demonstrated that An. albimanus populations from historical malaria foci in Quintana Roo are susceptible to the main insecticides used by the Ministry of Health.
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Anopheles , Resistência a Inseticidas , Inseticidas , Mosquitos Vetores , Animais , Anopheles/genética , Anopheles/efeitos dos fármacos , Inseticidas/farmacologia , Resistência a Inseticidas/genética , México , Feminino , Mosquitos Vetores/genética , Mosquitos Vetores/efeitos dos fármacos , Malária/transmissãoRESUMO
BACKGROUND: Orthoflavivirus ilheusense (ILHV) is a member of the Flaviviridae family. It was first isolated in 1944 from pools of Aedes serratus and Psorophora ferox mosquitoes; however, it has also been detected in species of the genus Culex, such as Cx. portesi and Cx. coronator. The objective of this study was to examine the vector competence of Cx. quinquefasciatus mosquitoes to ILHV infection and the subsequent transmission of the virus through their saliva during feeding on blood. METHODS: F1 generation females of Cx. quinquefasciatus (Ananindeua/PA) were orally infected with goose blood infected with strain BeH7445, and body, head and saliva samples were analyzed at 7, 14, and 21 dpi using the techniques of virus isolation in cells and indirect immunofluorescence. RESULTS: The presence of ILHV was not detected in the body and head samples of Cx. quinquefasciatus females at any of the three dpi's analyzed, indicating that the lineage of mosquitoes analyzed was resistant to ILHV. CONCLUSIONS: According to the results obtained in this study, the species Cx. quinquefasciatus proved resistant to ILHV, regardless of the virus titers to which it was exposed, which suggests the possibility that this species does not act as a vector in the ILHV transmission cycle.
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In the signal analysis context, the entropy concept can characterize signal properties for detecting anomalies or non-representative behaviors in fiscal systems. In motor fault detection theory, entropy can measure disorder or uncertainty, aiding in detecting and classifying faults or abnormal operation conditions. This is especially relevant in industrial processes, where early motor fault detection can prevent progressive damage, operational interruptions, or potentially dangerous situations. The study of motor fault detection based on entropy theory holds significant academic relevance too, effectively bridging theoretical frameworks with industrial exigencies. As industrial sectors progress, applying entropy-based methodologies becomes indispensable for ensuring machinery integrity based on control and monitoring systems. This academic endeavor enhances the understanding of signal processing methodologies and accelerates progress in artificial intelligence and other modern knowledge areas. A wide variety of entropy-based methods have been employed for motor fault detection. This process involves assessing the complexity of measured signals from electrical motors, such as vibrations or stator currents, to form feature vectors. These vectors are then fed into artificial-intelligence-based classifiers to distinguish between healthy and faulty motor signals. This paper discusses some recent references to entropy methods and a summary of the most relevant results reported for fault detection over the last 10 years.
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Light-Emitting Diodes (LEDs) have been effective light sources in attracting Anopheles mosquitoes, but the broad-spectrum white light, even with a wide-ranging application in lighting, have not been evaluated yet. In this study, the white light was field evaluated against the green one in the light trapping of anopheline mosquitoes by using two non-suction Silva traps and two CDC-type suction light traps. Anopheline mosquitoes were captured for two 21-night periods of collecting (2022 and 2023). In the first period, two LEDs were used per Silva trap, but three were used in the second one to increase the luminance/illuminance at traps. A CDC-type suction light trap equipped with an incandescent lamp was used in 2022 and a CDC-type suction light trap equipped with a 6 V-white light (higher luminance/illuminance) in 2023. A total of eight species and 3,289 specimens were captured in both periods. The most frequent species were Anopheles triannulatus s.l., An. goeldii, An. evansae and An. argyritarsis. In 2022, white LEDs were less attractive to anopheline mosquitoes than the other light sources, but without statistical difference among treatments (F = 2.703; P = 0.0752; df = 2). In 2023, even with an increased luminance/illuminance at traps, no statistical difference was found between the two LED-baited Silva traps (F = 6.690; P = 0.0024; df = 2), but rather between the 6 V-white-baited CDC-type suction light trap and green-baited Silva traps. Due to some drawbacks and the lower abundance of individuals caught by using white LEDs, the narrow-banded green LEDs is preferable to white ones for attracting anophelines.
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Anopheles , Luz , Controle de Mosquitos , Animais , Anopheles/fisiologia , Anopheles/efeitos da radiação , Controle de Mosquitos/métodos , Controle de Mosquitos/instrumentaçãoRESUMO
BACKGROUND: In malaria endemic regions of the Peruvian Amazon, rainfall together with river level and breeding site availability drive fluctuating vector mosquito abundance and human malaria cases, leading to temporal heterogeneity. The main variables influencing spatial transmission include location of communities, mosquito behaviour, land use/land cover, and human ecology/behaviour. The main objective was to evaluate seasonal and microgeographic biting behaviour of the malaria vector Nyssorhynchus (or Anopheles) darlingi in Amazonian Peru and to investigate effects of seasonality on malaria transmission. METHODS: We captured mosquitoes from 18:00 to 06:00 h using Human Landing Catch in two riverine (Lupuna, Santa Emilia) and two highway (El Triunfo, Nuevo Horizonte) communities indoors and outdoors from 8 houses per community, during the dry and rainy seasons from February 2016 to January 2017. We then estimated parity rate, daily survival and age of a portion of each collection of Ny. darlingi. All collected specimens of Ny. darlingi were tested for the presence of Plasmodium vivax or Plasmodium falciparum sporozoites using real-time PCR targeting the small subunit of the 18S rRNA. RESULTS: Abundance of Ny. darlingi varied across village, season, and biting behaviour (indoor vs outdoor), and was highly significant between rainy and dry seasons (p < 0.0001). Biting patterns differed, although not significantly, and persisted regardless of season, with peaks in highway communities at ~ 20:00 h in contrast to biting throughout the night (i.e., 18:00-06:00) in riverine communities. Of 3721 Ny. darlingi tested for Plasmodium, 23 (0.62%) were infected. We detected Plasmodium-infected Ny. darlingi in both community types and most (20/23) were captured outdoors during the rainy season; 17/23 before midnight. Seventeen Ny. darlingi were infected with P. vivax, and 6 with P. falciparum. No infected Ny. darlingi were captured during the dry season. Significantly higher rates of parity were detected in Ny. darlingi during the rainy season (average 64.69%) versus the dry season (average 36.91%) and by community, Lupuna, a riverine village, had the highest proportion of parous to nulliparous females during the rainy season. CONCLUSIONS: These data add a seasonal dimension to malaria transmission in peri-Iquitos, providing more evidence that, at least locally, the greatest risk of malaria transmission is outdoors during the rainy season mainly before midnight, irrespective of whether the community was located adjacent to the highway or along the river.