Monitoring of resistance or susceptibility of adults and larvae of Amblyomma cajennense (Acari: Ixodidae) to synthetic acaricides in Goiás, Brazil.

Amblyomma cajennense or the Cayenne tick is a three-host ixodid tick species of low parasitic specificity that is the principal vector of Brazilian spotted fever. The primary objective of this study was to evaluate the possible development of resistance by adult specimens of A. cajennense to deltamethrin, a synthetic pyrethroid insecticide and the principal miticide/acaricide commercially available in the region. The second objective was to monitor the susceptibility and/or resistance of larvae of this species to 12 synthetic acaricide formulations selected from the principal pesticides available in Goiás for the control of ticks. Unfed male and female adult specimens of A. cajennense were collected from leaves of bushes along a nature trail in the municipality of Caldas Novas, Goiás, Brazil. They were submitted to immersion in the highest recommended dose of deltamethrin and subsequently, were placed in contact with filter paper impregnated with the substance. The toxicological effects caused by the insecticide were observed every 6 h over a 36 h period. To obtain larvae, engorged females of A. cajennense were collected from naturally infested horses that had been free of acaricidal residue for at least 45 days, in farms situated in five different municipalities in the state (Caldas Novas, Hidrolândia, Goiás, Terezópolis and Goiânia). The larvae were exposed to different concentrations of 12 commercially available acaricidal formulations using the larval packet test (LPT) method. The control groups were treated with distilled water alone. The bioassays were performed in quadruplicate at a temperature of 27 °C, relative air humidity > 80% and 12 h light/dark cycles. The mean percentage of mortality MX was 72.6% in the adult specimens after 24 h of exposure to the dose of deltamethrin recommended by the manufacturer, characterizing a status of resistance. MX of 82, 89, 89.6 and 90% of the larvae were obtained, respectively, for deltamethrin, cypermethrin + piperonyl butoxide (PBO), amitraz and permethrin, characterizing a status of probable resistance of the larvae to these acaricides. No significant mortality was found in the control groups.

Ultrastructural Analysis of Mouthparts of Adult Horn Fly (Diptera: Muscidae) From the Brazilian Midwest Region.

The ultrastructure of the mouthparts of Haematobia irritans (L.) was investigated by scanning electron microscopy. The morphological characteristics of the maxillary palps, labium (prementum and postmentum), labrum, hypopharynx, haustellum, and labellar lobes are described, as well as of the sensilla evidenced on all the surface of the mouthparts, and the set of different positions assumed by the mouth apparatus of this fly. Based on their morphology, 12 well-differentiated sensilla were identified, among three types of cuticular sensilla: trichoidea, coeloconica, and campaniformia. A slight sexual dimorphism in the sensilla patterns found in the mouthparts of H. irritans was evidenced. These observations are discussed with reference to the current literature on the functional morphology of sense organs of Insecta. These results could facilitate the recognition of the chemosensory sensilla by electrophysiological techniques, and foment future taxonomic and phylogenetic studies to better elucidate the evolution of Diptera, Muscomorpha.

Ultrastructure of the Antennae and Sensilla of Nyssomyia intermedia (Diptera: Psychodidae), Vector of American Cutaneous Leishmaniasis.

The antennal sensilla and the antenna of females Nyssomyia intermedia, one of the main vectors of American cutaneous leishmaniasis, were studied by scanning electron microscopy. The main goal was to characterize the quantity, typology, and topography of the sensilla with particular attention to the olfactory types. The insects were captured in the city of Corte de Pedra, State of Bahia, Brazil, by CDC-type light traps and raised in a laboratory as a new colony. Fourteen well-differentiated sensilla were identified, among six cuticular types: trichoidea, campaniformia, squamiformia, basiconica, chaetica, and coeloconica. Of these, six sensilla were classified as olfactory sensilla due to their specific morphological features. Smaller noninnervated pilosities of microtrichiae type were also evidenced by covering all antennal segments. The antennal segments differ in shapes and sizes, and the amount and distribution of types and subtypes of sensilla. This study may foment future taxonomic and phylogenetic analysis for a better evolutionary understanding of the sand flies. Besides, it may assist the targeting of future electrophysiological studies by Single Sensillum Recording, and aim to develop alternative measures of monitoring and control of this vector.

Fine structure and distribution pattern of antennal sensilla of Lutzomyia longipalpis (Diptera: Psychodidae) sand flies.

The specific aims of this work were to examine the antennal sensilla of Lutzomyia longipalpis (Lutz & Neiva 1912) (Diptera: Psychodidae) adults and to characterize their typology and topography, with special attention to olfactory sensilla. The surfaces of the antennal segments of Lu. longipalpis males and females were studied by scanning electron microscopy (SEM). Lu. longipalpis used in the current study were obtained from a colony originating from Lapinha Cave, Minas Gerais state, Brazil. Microtrichiae and 11 subtypes of sensilla were observed and characterized according to the following categories: five subtypes of trichoid sensilla (short, medium, long blunt-tipped, long pointed-tipped, and apical), two coeloconic sensilla (grooved and praying hands), and campaniform, chaetic, basiconic, and squamiform sensilla. SEM analyses showed few differences between males and females in the typology, topography, and quantity of antennal sensilla described. The current study is the first to identify several categories of antennal sensilla of the genus Lutzomyia and their distribution patterns. The identification of these sensillar types may be important in planning future electrophysiological studies to develop alternative measures of control and monitoring of Lu. longipalpis.

Ultrastructure of contact-chemoreceptor sensilla found among the genae of female Gasterophilus nasalis.

Scanning electron microscopy was used to observe contact-chemoreceptor sensilla in the genae of the anterior vestigial mouthparts of female Gasterophilus nasalis. These were of the uniporous trichoid type and were surrounded by mechanosensory aporous trichoid sensilla of variable size. Contact-chemoreceptor sensilla could be involved in detecting different chemical substances, including the equine kairomones that stimulate females to lay eggs on the hair of the host and/or the short-range sexual pheromones used in precopulatory courtship. The probable functions of these sensilla are discussed with reference to the current literature on the sensorial organs of muscomorphid dipterans.

Observations on mouthparts of Dermatobia hominis (Linneaus Jr., 1781) (Diptera: Cuterebridae) by scanning electron microscopy.

The ultrastructure of the mouthparts of Dermatobia hominis was studied using scanning electron microscopy. The morphological characteristics of the segments, articulations, sensory organs, and pilose covering are described. Mechanoreceptors of the long trichoid sensillum and smaller trichoid sensillum types were observed, as well as labellar gustatory receptors of the basiconic sensillum type, which differed between the sexes. These observations are discussed with reference to the current literature on the morphology and sense organs of dipteran mouthparts, and the prevailing view that the adult mouthparts of this species are non-functional is challenged.

Evaluation of activity of the crude ethanolic extract of Magonia pubescens St. Hil (Sapindaceae) against larvae of the cattle tick Rhipicephalus (Boophilus) microplus (Canestrini, 1887) (Acari: Ixodidae)

The acaricidal potential of the crude ethanolic extract (c.e.e.) of the stem peel of Magonia pubescens was evaluated against larvae of Rhipicephalus (Boophilus) microplus. The larvae were placed in filter paper envelopes impregnated with different concentrations of c.e.e., dissolved in dimethylsulfoxide (DMSO) and distilled water for determination of lethal concentrations (LC). The following treatments were used: 1. Envelopes of dry filter paper; 2. Envelopes of filter paper moistened with distilled water; 3. Envelopes of filter paper moistened with a solution of DMSO in distilled water; and 4. Envelopes moistened with 2 mL of each concentration of the c.e.e. to be tested. The bioassays were carried out in quadruplicate at 27°±1° C and RH e"80 percent and 12h light. Mortality was observed after 48 h, LC50 and LC99 values of 365 and 4,000 ppm being obtained. There was no significant mortality in larvae exposed to the first three treatments (p < 0.05).

Este trabalho objetivou avaliar o potencial acaricida do extrato-bruto etanólico (e.b.e.) da casca do caule de Magonia pubescens sobre larvas do carrapato bovino Rhipicephalus (Boophilus) microplus. As larvas foram acondicionadas em B.O.D. climatizada, em envelopes de papel filtro impregnados com diferentes concentrações do e.b.e., solubilizado com dimetilsulfóxido (DMSO) e água destilada, para determinação das Concentrações Letais (CL). Foram realizados os seguintes tratamentos: 1. envelopes de papel filtro seco; 2. envelopes de papel filtro umedecidos com água destilada; 3. envelopes de papel filtro umedecidos com solução de DMSO e água destilada; e 4. envelopes umedecidos com 2 mL de cada concentração do e.b.e. testada. Os bioensaios foram feitos em quadruplicata, em uma câmara climatizada a 27°±1° C, URe"80 por cento e fotofase natural de 12 horas. A mortalidade foi observada após 48h. Obtiveram-se as CL50 de 365 e CL99 de 4.000 ppm. Não houve mortalidade significativa para os três primeiros tratamentos (p<0,05).

Isolamento e perfil de suscetibilidade de bactérias de pé diabético e úlcera de estase venosa de pacientes admitidos no pronto-socorro do principal hospital universitário do estado de Goiás, Brasil / Isolation and susceptibility profile of bacteria in diabetic foot and venous stasis ulcer of patients admitted to the emergency room of the main university hospital in the state of Goiás, Brazil / Isolation and susceptibility profile of bacteria in diabetic foot and venous stasis ulcer of patients admitted to the emergency room of the main university hospital in the state of Goiás, Brazil

CONTEXTO: Lesões infectadas de membros inferiores (úlceras diabéticas e úlceras de estase venosa) são causa de grande sofrimento e incapacitação funcional com impacto social, econômico e aumento do risco de complicações severas. OBJETIVO: Caracterizar a microbiota e determinar o perfil de suscetibilidade antimicrobiana das bactérias isoladas de lesões de membros inferiores secundárias a úlcera de estase venosa e pé diabético. MÉTODOS: Foram incluídos no estudo pacientes portadores de lesões de membros inferiores, sendo diabéticos, e pacientes com úlcera de estase venosa, atendidos em um serviço de urgência de um hospital universitário de Goiânia (GO), no período de fevereiro de 2005 a agosto de 2006. A coleta de material foi realizada com swab de algodão para realização de cultura e teste de sensibilidade antimicrobiana, empregando-se técnicas preconizadas. RESULTADOS: Das amostras analisadas, foi detectada a presença de bactérias em 88,46 por cento. Os cocos gram-positivos foram caracterizados como Staphylococcus aureus e Staphylococcus epidermidis. Dentre os bastonetes gram-negativos, detectou-se Pseudomonas aeruginosa,Escherichia coli,Proteus mirabilis e Enterobacter sp. CONCLUSÕES: Os microrganismos isolados das lesões de membros inferiores (pé diabético e úlcera de estase venosa) incluíram bactérias gram-positivas e negativas, sendo Staphylococcus aureus,Pseudomonas aeruginosa e Escherichia coli as mais freqüentes, com elevada resistência a diversos antimicrobianos.

BACKGROUND: Infected lower limb injuries (diabetic ulcers and venous stasis ulcers) cause great suffering and functional disability with social and economic impact and increase in risk of severe complications. OBJECTIVE: To characterize the microbiota and determine the antimicrobial susceptibility profile of isolated bacteria in lower limb injuries secondary to the venous stasis ulcer and diabetic foot. METHODS: Patients with lower limb lesions were included in the study, both diabetics and patients with venous stasis ulcer, receiving care at the emergency service of a university hospital in Goiânia (Brazil) from February 2005 to August 2006. Samples were collected with cotton swab to perform culture and antimicrobial sensitivity test applying standardized techniques. RESULTS: Presence of bacteria was detected in 88.46 percent of the samples. Gram-positive cocci were characterized as Staphylococcus aureus and Staphylococcus epidermidis. Among Gram-negative rods, Pseudomonas aeruginosa,Escherichia coli,Proteus mirabilis and Enterobacter sp. were detected. CONCLUSIONS: Isolated microorganisms of lower limb injuries (diabetic foot and venous stasis ulcer) included Gram-positive and Gram-negative bacteria, such as Staphylococcus aureus,Pseudomonas aeruginosa and Escherichia coli, which werethemost frequent and highly resistant to several kinds of antimicrobial agents.

Dispositivo para testes biológicos com inseticida, na formulaçäo de ultrabaixo volume e termonebulizaçäo / Experimental device of biological test inseticida in ultra-low-volume and thermal fog formulation

Para realizar testes biológicos com inseticidas em formulaçäo de ultrabaixo volume (UBV) e termobulizaçäo (FOG), com a finalidade de combater mosquitos hematófagos, construiu-se um dispositivo para exposiçäo ao inseticida e repouso dos mosquitos durante o período de observaçäo. Este dispositivo mostrou ser prático, de fácil manuseio e eficiente na realizaçäo dos bioensaios

Influência da temperatura na biologia de tritomíneos. XX.Triatoma maculata (Erichson,1848) (Hemiptera, Reduviidae) / The influence of temperature on the biology of triatominae.XX. Triatoma maculata (Erichson, 1848) (Hemiptera, Reduviidae)

Estudou-se o efeito da temperatura no ciclo evolutivo de Triatoma maculata (Erichson, 1848) para estabelecer a sua influência no desenvolvimento do triatomíneo, conhecer alguns aspectos de sua biologia e dominar técnicas de criaçäo para viabilizar o uso dessa espécie nos testes experimentais em doença de Chagas. O período médio de incubaçäo dos ovos de T. maculata, para machos e fêmeas, foi de 29 e de 16 dias, à temperatura de 25º e 30ºC, respectivamente. A temperatura de 25ºC, a duraçäo média do ciclo evolutivo para machos e fêmeas,foi, respectivamente de 223,5 e 222,3 dias e, de 168,7 e 167,2 dias, a 30ºC. Os experimentos foram realizados a 25ñ 0,5ºC e 30 ñ 1,0ºC, com umidade de 70 ñ 5(pör cento) e fotoperíodo de 12 horas

Açäo da deltametrina na dosagem de 0,8g/Ha sobre o aedes aegypti (Lin., 1762), na formulaçäo de ultra-baixo-volume / Action of deltamethrin in the dose of 0,8 g/Ha over the aedes aegypti, in ultra low volume fformulation

Realizaram-se provas biológicas visando determinar a suscetibilidade do aedes aegypti(Lin., 1762)à açäo da deltametrina, na concentraçäo de 1 por cento, aplicada em ultrabaixo volume(UBV), em diferentes horários na dosagem de 0,8 g/Ha. A aplicaçäo da deltametrina foi realizada com equipamento LECO UBV/HD, acoplado à carroceria de uma pick-up. Foram realizados 15 ensaios com 24 gaiolas e tendo em cada uma 20 mosquitos, colocadas no intradomicílio e peridomicílio. Os mosquitos ficaram expostos à deltametrina por uma hora na área-teste. Posteriormente, foram levados ao laboratório e transferidos das gaiolas de exposiçäo para as de repouso, onde permaneceram sob observaçäo por 36 horas. utilizaram-se 200 mosquitos como controle, para cada bioensaio, colocados a aproximadamente 2 Km da área-teste. A dosagem de 0,8g/Ha mostrou-se eficaz para combater o aedes aegypti. As fêmeas alimentadas com sangue foram mais resistentes à deltametrina do que as em jejum. Machos alimentados com água açucarada foram mais resistentes do que os em jejum e estes foram mais suscetíveis ao inseticida do que as fêmeas. Estes dados säo orientativos para a realizaçäo de provas biológicas, confirmando a premissa de se utilizar apenas fêmeas alimentadas para determinar a suscetibilidade desse mosquito ao inseticida. Os horários das 12 e 18 horas mostraram-se como os melhores para aplicaçäo da deltametrina para matar o a. aegypti. Houve mortalidade de 0,9 por cento no grupo controle. Os bioensaios foram realizado à temperatura média de 27,5mais ou menos 0,4 graus C,e 66,1 mais ou menos 2,5por cento de umidade relativa do ar

Teste de suscetibilidade do aedes aegypti (Linnaeus, 1762) ao cythion / Susceptibility test of Aedes aegypti (linnaeus, 1762) with the Cythion

Realizaram-se testes biológicos para verificar a açäo do Cythion, na formulaçäo em ultrabaixo volume (UBV), sobre o Aedes aegypti (Linnaeus, 1762). O cYthion a 95 por cento, em UBV, foi aplicado pelo equipamento LECO, na dosagem de 120ml por minuto. Utilizaram-se 20 gaiolas com 20 insetos em cada uma. Cem insetos foram empregados como controle, colocados cerca de 2,5km fora da área tratada. Os mosquitos utilizados para teste foram distribuidos no intradomicilio e no quintal, em gaiolas, perfazendo um total de 300 exemplares para cada ambiente, que ficaram expostos ao inseticida por uma hora. Logo em seguida, foram levados ao laboratório e transferidos das gaiolas de exposiçäo para as de repouso, onde permaneceram em observaçäo por 36 horas. A mortalidade média observada para o A. aegypti, após este período, foi de 58 por cento para fêmeas e de 63,3 por cento para machos. Näo houve mortalidade no grupo controle