Francisco Marlon Carneiro Feijó

Control of phlebotomine (Diptera: Psychodidae) leishmaniasis vectors

Phlebotomines are of medical and veterinary concern as they vector leishmaniasis, bartonellosis and some arboviruses. The adaptations of some species to places modified by humans bring these vectors into contact with dwellings, which can facilitate disease transmission, and the vector control strategies adopted have rendered controversial results. Regarding leishmaniasis, for instance, which vector and reservoirs control can be effective, there is an assumption that the incidence of human infection is directly related to the number of infectious dogs, as well as to entomological factors. Therefore, vector control can provide a cheaper and more practical solution to prevent cases of leishmaniasis. Nevertheless, due to the complexity of the factors involved, chemical control is still essential, and biological insecticides and insecticide plants, for example, represent areas for study that should be encouraged and developed since they show promising results. This paper summarizes the control strategies adopted so far, especially the methods and efficiency of the entomological components of leishmaniasis control programs.

Monitoring of Lutzomyia longipalpis Lutz & Neiva, 1912 in an area of intense transmission of visceral leishmaniasis in Rio Grande do Norte, Northeast Brazil

Urban increase of visceral leishmaniasis (VL) in Brazil is associated with the adaptation of its vector, Lutzomyia longipalpis, to environments modified by humans. The present study reports the results of an entomological monitoring of L. longipalpis and the effect of environmental variables on its population density. Sandflies were captured in the municipality of Mossoró, State of Rio Grande do Norte, Northeastern Brazil, from January 2005 to December 2006. Two CDC light traps were placed monthly for four consecutive nights in the peridomicile of selected households. Data analysis was based on the chi-square test and linear regression. A total of 2,087 sandflies were captured, 99.86% of which were L. longipalpis. A higher proportion of females were captured (p < 0.05). Monthly analysis of the variables temperature, relative humidity and rainfall did not show a significant influence on population density. However, there were seasonal differences: approximately 70% of sand flies were captured during the rainy season (p < 0.05). The predominant species, L. longipalpis, is present in substantial number, representing a public health risk. Therefore, because of higher prevalence during the rainy season, we recommend intensified VL control measures before and during this season to reduce the risk of disease transmission.

Sandflies (Psychodidae: Phlebotominae) survey in an urban transmission area of visceral leishmaniasis, Northeastern Brazil

Visceral leishmaniasis (VL) is a major public health challenge in Brazil, especially in states where it is endemic. The aim of this study was to investigate the relationship of sand fly population density with environmental variables (temperature, rainfall and relative humidity) in urban areas of the city of Mossoró, Rio Grande do Norte, Northeastern Brazil. Sand flies were captured with Center Disease Control (CDC) traps installed monthly in the intra and peridomicile of three houses. Data analysis was based on the chi-square test and linear regression. A total of 7,347 sand flies were captured, being 93.85% Lutzomyia longipalpis and 6.15% Lutzomyia evandroi. Sand flies were more commonly found in the peridomicile and there was no difference between the number of males and females. The variables rainy season as well as relative humidity and rainfall, alone or together, did not have an effect on sand fly population density. However, high temperatures had a negative effect. The study of the behavior of sand flies in specific units of endemic areas can provide input to public health authorities for planning appropriate VL vector control measures.

The effects of the fungus Metarhizium anisopliae var. acridum on different stages of Lutzomyia longipalpis (Diptera: Psychodidae)

The control of Visceral Leishmaniasis (VL) vector is often based on the application of chemical residual insecticide. However, this strategy has not been effective. The continuing search for an appropriate vector control may include the use of biological control. This study evaluates the effects of the fungus Metarhizium anisopliae var. acridum on Lutzomyia longipalpis. Five concentrations of the fungus were utilized, 1 x 10(4) to 1 x 10(8) conidia/ml, accompanied by controls. The unhatched eggs, larvae and dead adults previously exposed to fungi were sown to reisolate the fungi and analysis of parameters of growth. The fungus was subsequently identified by PCR and DNA sequencing. M. anisopliae var. acridum reduced egg hatching by 40%. The mortality of infected larvae was significant. The longevity of infected adults was lower than that of negative controls. The effects of fungal infection on the hatching of eggs laid by infected females were also significant. With respect to fungal growth parameters post-infection, only vegetative growth was not significantly higher than that of the fungi before infection. The revalidation of the identification of the reisolated fungus was confirmed post-passage only from adult insects. In terms of larvae mortality and the fecundity of infected females, the results were significant, proving that the main vector species of VL is susceptible to infection by this entomopathogenic fungus in the adult stage.

Microbiota fúngica de Melipona subnitida Ducke (Hymenoptera: Apidae)

O presente trabalho descreve a ocorrencia de fungos filamentosos sobre a superficie do corpo de abelhas da especie Melipona subnitida Ducke, que habita regioes pedregosas do semi-arido nordestino. Abelhas com causa de morte natural foram coletadas de colmeias pertencentes ao Centro de Multiplicacao de Animais Silvestres da Universidade Federal Rural do Semi-Arido. Foram encontrados os fungos: Aspergillus sp. 6 (37,5%); Aspergillus niger 2 (12,5%); Penicilium sp. 2 (12,5%); Aspergillus terreus 1 (6,3%); Curvularia sp. 1 (6,3%); Monilia sp. 1 (6,3%); Nigrospora sp. 1 (6,3%); Cladosporium sp. 1 (6,3%); Tricoderma sp. 1 (6,3%).

Rhinocerebral and rhinopharyngeal conidiobolomycosis in sheep

The present study aimed to report the occurrence as well as the clinical, laboratorial, pathological and mycological findings of three outbreaks of rhinocerebral and rhinopharyngeal conidiobolomycosis in sheep from Rio Grande do Norte state, Brazil. A total of six sheep with clinical signs of conidiobolomycosis were evaluated, and information on history was obtained from ranchers. Clinical signs included depression, progressive emaciation, sero-sanguinolent nasal discharge, tachycardia, dyspnea, miosis and unilateral exophthalmia with increased ocular globe volume, corneal ulceration and nervous system signs. The main hematological alteration was neutrophilia. Serum biochemical evaluation revealed increased values for AST, GGT, creatinine, urea, and glucose, and decreased total proteins and albumin levels. Cerebrospinal fluid analysis showed the presence of fibrin reticules and pleocytosis. Upon necropsy, longitudinal sections of the head revealed the presence of a nodular mass with a friable consistency and a white-yellowish coloration. Microscopic findings included meningitis, cortex necrosis and encephalitis with the presence of eosinophilic Splendore-Hoeppli substance. Histopathology of the lungs revealed a Splendore-Hoeppli-like material and hyperplasia of alveolar and bronchiolar epithelium. Renal lesions were suggestive of amyloidosis.

Knowledge of the Population about Visceral Leishmaniasis Transmission in Endemic Areas near the Banks of the Mossoró River in Northeastern Brazil

Visceral leishmaniasis (VL) is an anthropozoonosis with high prevalence and incidence in the Northeastern region of Brazil. This study aimed to determine whether people living near the Mossoró River in the city of Mossoró, Rio Grande do Norte, have knowledge of VL and to characterize the environmental properties of this region. Questionnaires were administered to 478 residents in three neighborhoods near the Mossoró River, addressing the population’s knowledge about VL and environmental characteristics. Most survey participants were female, with ages between 18 and 40 years, 53.8% had completed primary education, and 61.5% owned pet dogs (p < 0.05). The majority (95.9%) showed little knowledge about the characteristics inherent to sandflies, and 85.3% were unaware of the environments preferred by this vector (p < 0.05). Sewage from the homes of respondents was mainly dumped into the river (44.6%), and 76.6% of the respondents complained about the accumulation of garbage in the streets (p < 0.05). The association between education and knowledge about the transmission of VL and preferred vector locations was statistically significant (p < 0.05). The lack of knowledge in the population about VL and the residential environment indicates a risk of maintaining sand fly habitats and hence disease transmission.

Suppurative intracranial processes in 15 domestic ruminants

In addition to listeriosis which is relatively common in ruminants, there are three other uncommon suppurative intracranial processes (SIP) identifiable in adult ungulates as brain abscess, basilar empyema and suppurative meningitis. The present paper reports the epidemiological, clinical, laboratorial, pathological and microbiological findings of 15 domestic ruminants with SIP. A total of 15 animals were selected (eight sheep, four cattle and three goats); with the definitive diagnoses of basilar empyema (n=3), brain abscess (n=1), listeriosis (n=5) and suppurative meningitis (n=6). Hematology revealed leukocytosis with inversion of the lymphocyte/ neutrophil ratio in 4 cases. In the majority of animals, cerebrospinal fluid (CSF) presented light yellow coloration and cloudy aspect due to neutrophilic pleocytosis (15 - 997 leukocytes/µL). Microbiological culture of CSF or central nervous system (CNS) fragments resulted on isolation of Trueperella (Arcanobacterium) pyogenes,Listeria monocytogenes,Escherichia coli and Stenotrophomonas sp. In a goat with thalamic abscess, microbiological assay was not performed, but Gram positive bacilli type bacteria were observed in histology. The diagnosis of these outbreaks was based on the association of epidemiological, clinical, pathological and bacteriological findings; reiterating that the infectious component remains an important cause of CNS disease in domestic ruminants and also shows the need for dissemination of information about the most effective preventive measures for the ranchers.

Isolamento de Alcaligenes faecalis em peixe Betta splendens Regan, 1910 no Brasil

This paper aimed to describe one case of infection by Alcaligenes faecalis in an ornamental fish Betta splendens, including clinical, pathological, and bacteriological evaluation. A female fish weighing 16 g initially showed discrete ulcerative lesions in the integument, inappetence, progressive weight loss, lethargy, dyspnea, and increased volume in the left lateral region. Necropsy revealed bilateral exophthalmia, corneal opacity, ascites, and subcutaneous abscess causing distension of the celomatic cavity. Histological changes of the skin were characterized by abscess, necrosis, hemorrhage, and inflammatory infiltrate consisting mainly of heterophils. Microbiological assays using the exudates and venous blood isolated exclusively A. faecalis.

Caracterização da microbiota auricular de cutias (Dasyprocta aguti) criadas em cativeiro

The aim of this study was to identify the aerobic bacteria of the auricular natural microbiota from healthy agoutis (Dasyprocta aguti Linnaeus, 1758). In the total, 48 agoutis were used in this experiment, being 32 adults and 16 puppies (both groups divided into equal parts between males and females). The animals were raised under captive conditions, in the Brazilian Semiarid. From each animal, a sample of auricular secretion was collected from each auricular pinna and processed for microbiological analyses. A total of 96 samples were collected and analyzed by colony macroscopic format, cytology and by biochemistry proofs with the objective of isolate and identify the microorganisms. The main bacteria found were Staphylococcus spp. (47.26%), Streptococcus spp. (12.80%), Bacillus spp. (22.73%) and Corynebacterium spp. (17.30%). As conclusion, the most frequent bacteria in auricular pinna of healthy agoutis are Gram-positive cocci and rods, similarly to found in some pets.