Virulence profile of ten Paracoccidioides brasiliensis isolates: association with morphologic and genetic patterns

Ten isolates of Paracoccidioides brasiliensis were examined for differences in virulence in outbred mice intravenously inoculated with the fungus, associated with mycelial morphology, and genetic patterns measured by random amplified polymorphic DNA (RAPD). Virulence was evaluated by viable yeast cell recovery from lungs and demonstration of histopathologic lesions in different organs. The results showed that the isolates presented four virulence degrees: high virulence, intermediate, low and non-virulence. RAPD clustered the isolates studied in two main groups with 56% of genetic similarity. Strains with low virulence, Pb265 or the non-virulent, Pb192, showed glabrous/cerebriform morphology and high genetic similarity (98.7%) when compared to the other isolates studied. The same was observed with Bt79 and Bt83 that shared 96% genetic similarity, cottony colonies and high virulence. The RAPD technique could only discriminate P. brasiliensis isolates according to glabrous/cerebriform or cottony colonies, and also high from low virulence strains. Isolates with intermediate virulence such as Pb18, Pb18B6, Bt32 and Bt56 showed variability in their similarity coefficient suggesting that RAPD was able to detect genetic variability in this fungal specie. Virulence profile of P. brasiliensis demonstrated that both mycelial morphologic extreme phenotypes may be associated with fungal virulence and their in vitro subculture time. Thus, RAPD technique analysis employed in association with virulence, morphologic and immunologic aspects might prove adequate to detect differences between P. brasiliensis isolates.

DIFFERENTIATION BETWEEN Nocardia spp. AND Mycobacterium spp.: CRITICAL ASPECTS FOR BACTERIOLOGICAL DIAGNOSIS

New methodologies were developed for the identification of Nocardia but the initial diagnosis still requires a fast and accurate method, mainly due to the similarity to Mycobacterium, both clinical and bacteriologically. Growth on Löwenstein-Jensen (LJ) medium, presence of acid-fast bacilli through Ziehl-Neelsen staining, and colony morphology can be confusing aspects between Nocardia and Mycobacterium. This study describes the occurrence of Nocardia spp. in a mycobacterial-reference laboratory, observing the main difficulties in differentiating Nocardia spp. from Mycobacterium spp., and correlating isolates with nocardiosis cases. Laboratory records for the period between 2008 and 2012 were analyzed, and the isolates identified as Nocardia sp. or as non-acid-fast filamentous bacilli were selected. Epidemiological and bacteriological data were analyzed as well. Thirty-three isolates identified as Nocardia sp. and 22 as non-acid-fast bacilli were selected for this study, and represented 0.12% of isolates during the study period. The presumptive identification was based on macroscopic and microscopic morphology, resistance to lysozyme and restriction profiles using the PRA-hsp65 method. Nocardia spp. can grow on media for mycobacteria isolation (LJ and BBL MGIT™) and microscopy and colony morphology are very similar to some mycobacteria species. Seventeen patients (54.8%) were reported and treated for tuberculosis, but presented signs and symptoms of nocardiosis. It was concluded that the occurrence of Nocardia sp. during the study period was 0.12%. Isolates with characteristics of filamentous bacilli, forming aerial hyphae, with colonies that may be pigmented, rough and without the BstEII digestion pattern in PRA-hsp65 method are suggestive of Nocardia spp. For a mycobacterial routine laboratory, a flow for the presumptive identification of Nocardia is essential, allowing the use of more accurate techniques for the correct identification, proper treatment and better quality of life for patients.

Phenotypic characterization of three clinical isolates of Burkholderia pseudomallei in Ceará, Brazil

Burkholderia pseudomallei, the causative agent of melioidosis was found in a small cluster of cases in Tejuçuoca, Ceará, Brazil. Tests were carried out to determine its phenotypic characteristics: colony morphology on Ashdown agar and MacConkey agar, biochemical profile in conventional biochemical tests and API 20NE, arabinose assimilation and susceptibility testing by disk diffusion, comparing with data in the literature. This study confirms the presence of B. pseudomallei in Brazil and describes its characteristics.

Morphology and stability of aggregates of an Oxisol according to tillage system and gypsum application

Morphological characterization and aggregate stability is an important factor in evaluating management systems. The aim of this paper is to evaluate the stability and morphology of the aggregates of a dystrophic Oxisol managed with no-tillage and conventional tillage with and without the residual action of gypsum. The experimental design was randomized blocks arranged in split-split plot, where the treatments were two soil management systems (plots) with 0 and 2000 kg ha-1 of gypsum (subplots) and five depths (0-0.05, 0.05-0.10, 0.10-0.15, 0.15-0.20 and 0.20-0.30 m) as the subsubplots, with four replications. The aggregate morphology was determined through images and later evaluated by the Quantporo software. Stability was determined by the wet method. The results showed that the no-tillage system, with or without gypsum residual effect, provided the aggregates with the largest geometric diameters. The combination of no-tillage system and the gypsum residual effect provided rougher aggregates.

Liver morphology with emphasis on bile ducts changes and survival analysis in mice submitted to multiple Schistosoma mansoni infections and chemotherapy

In an attempt to be as close as possible to the infected and treated patients of the endemic areas of schistosomiasis (S. mansoni) and in order to achieve a long period of follow-up, mice were repeatedly infected with a low number of cercariae. Survival data and histological variables such as schistosomal granuloma, portal changes, hepatocellular necrosis, hepatocellular regeneration, schistosomotic pigment, periductal fibrosis and chiefly bile ducts changes were analysed in the infected treated and non treated mice. Oxamniquine chemotherapy in repeatedly infected mice prolonged survival significantly when compared to non-treated animals (chi-square 9.24, p = 0.0024), thus confirming previous results with a similar experimental model but with a shorter term follow-up. Furthermore, mortality decreased rapidly after treatment suggesting an abrupt reduction in the severity of hepatic lesions. A morphological and immunohistochemical study of the liver was carried out. Portal fibrosis, with a pattern resembling human Symmers fibrosis was present at a late phase in the infected animals. Bile duct lesions were quite close to those described in human Mansonian schistosomiasis. Schistosomal antigen was observed in one isolated altered bile duct cell. The pathogenesis of the bile duct changes and its relation to the parasite infection and/or their antigens are discussed.

Comparative morphometry and morphology of Anopheles aconitus Form B and C eggs under scanning electron microscope

Comparative morphometric and morphological studies of eggs under scanning electron microscope (SEM) were undertaken in the three strains of two karyotypic forms of Anopheles aconitus, i.e., Form B (Chiang Mai and Phet Buri strains) and Form C (Chiang Mai and Mae Hong Son strains). Morphometric examination revealed the intraspecific variation with respect to the float width [36.77 ± 2.30 µm (Form C: Chiang Mai strain) = 38.49 ± 2.78 µm (Form B: Chiang Mai strain) = 39.06 ± 2.37 µm (Form B: Phet Buri strain) > 32.40 ± 3.52 µm (Form C: Mae Hong Son strain)] and number of posterior tubercles on deck [2.40 ± 0.52 (Form B: Phet Buri strain) = 2.70 ± 0.82 (Form B: Chiang Mai strain) < 3.10 ± 0.32 (Form C: Chiang Mai strain) = 3.20 ± 0.42 (Form C: Mae Hong Son strain)], whereas the surface topography of eggs among the three strains of two karyotypic forms were morphologically similar.

Sanitary conditions of a colony of urban feral cats (Felis catus Linnaeus, 1758) in a zoological garden of Rio de Janeiro, Brazil

The colony of urban stray cats living in the Rio de Janeiro zoological garden was studied in order to develop a population and health control program. As many cats as possible were captured during two months (47 animals) and were classified according to gender, age, weight and coat markings. They were submitted to a general health evaluation, examined for the presence of ectoparasites and sent to a surgical neutering program. All animals had a blood sample drawn for CBC, platelet count, heartworm and retroviruses detection. Capillary blood smears were made for hemoparasites detection. Coat marking and colors were tabby (59.7%), followed by solid black (17%); torbie (10.6%); bicolor (10.6%) and harlequin (2.1%). The only ectoparasites found were fleas, which infested 28% of the animals. The hemoparasites found were Haemobartonella felis (38%) and piroplasmas that could not be differentiated between Cytauxzoon spp. and Babesia spp. (47%). No cat was found infected by Dirofilaria immitis or FeLV (Feline Leukemia Virus), although FIV (Feline Immunodeficiency Virus) antibodies could be detected (21%). There was no correlation between hemoparasites and FIV infections. The estimated total cat population (mark-recapture method) was 59; 68% female and 32% male, suggesting that a neutering program is in fact needed.

Characterization of rabies virus isolated from a colony of Eptesicus furinalis bats in Brazil

Some bat species have adapted to the expanding human population by acquiring the ability to roost in urban buildings, increasing the exposure risk for people and domestic animals, and consequently, the likelihood of transmitting rabies. Three dead bats were found in the yard of a house in an urban area of Jundiaí city in the state of São Paulo in southeast Brazil. Two of the three bats tested positive for rabies, using Fluorescent Antibody and Mouse Inoculation techniques. A large colony of Eptesicus furinalis was found in the house's attic, and of the 119 bats captured, four more tested positive for rabies. The objectives of this study were to report the rabies diagnosis, characterize the isolated virus antigenically and genetically, and study the epidemiology of the colony.

RELATED FACTORS FOR COLONIZATION BY Candida SPECIES IN THE ORAL CAVITY OF HIV-INFECTED INDIVIDUALS

The colonization of the oral cavity is a prerequisite to the development of oropharyngeal candidiasis. Aims: The aims of this study were: to evaluate colonization and quantify Candida spp. in the oral cavity; to determine the predisposing factors for colonization; and to correlate the levels of CD4+ cells and viral load with the yeast count of colony forming units per milliliter (CFU/mL) in HIV-positive individuals treated at a University Hospital. Saliva samples were collected from 147 HIV patients and were plated on Sabouraud Dextrose Agar (SDA) and chromogenic agar, and incubated at 30 ºC for 72 h. Colonies with similar morphology in both media were counted and the result expressed in CFU/mL. Results: Of the 147 HIV patients, 89 had positive cultures for Candida spp., with a total of 111 isolates, of which C. albicans was the most frequent species (67.6%), and the mean of colonies counted was 8.8 × 10³ CFU/mL. The main predisposing factors for oral colonization by Candida spp. were the use of antibiotics and oral prostheses. The use of reverse transcriptase inhibitors appears to have a greater protective effect for colonization. A low CD4+ T lymphocyte count is associated with a higher density of yeast in the saliva of HIV patients.

DISTINGUISHING Campa guianensis Aubl. FROM Campa procera D.C. (MELIACEAE) BY MORPHOLOGY OF YOUNG SEEDLINGS

Seedling morphology was studied in Campa guianensisAubl. and Carapa proceraD. C. from germination to 90 days age. In both species germination is hypogeal and cryptocotylar. Both have rare albino seedlings. Though both species have compound leaves when adult, C, proceraputs out an average total of six simple leaves at germination, while leaves of C. guianensisare compound at all stages. This is the best diagnostic character for separation of the two species at the young seedling stage. Not diagnostic, but none the less useful, is the fact, that polyembryonic seeds are often found in C. procera,but not observed in C guianensis.

Surface morphology of some Amphistomes (Trematoda) of Amazonian Fishes and the description of a new genus and species

The surface morphology of specimens from ten different genera of amphistomes (Trematoda, Cladorchiidae) from Amazonian fishes is described and illustrated. The importance of body shape as a generic character is considered. Morphological changes as a result of growth are shown and explained in relation to the species Dadaytrema oxycephala. Additionally, Doradamphistoma bacuensis gen. et sp. n. is described from the catfish, Megalodoras irwini Eigenmann, 1925.The new genus and species is elongate and flattened, with external pharyngeal pouches, an esophageal bulb, a spherical cirrus sac, a post-bifurcal genital pore and pre-equatorial testes.

Developmental morphology of mouthparts and foregut of the larvae and postlarvae of Lepidophthalmus siriboia Felder & Rodrigues, 1993 (Decapoda: Callianassidae)

In this study, the gross morphology of the mouthparts and foregut of the ghost shrimp Lepidophthalmus siriboia were investigated from larvae and postlarvae reared in the laboratory. The mouthparts (maxillae and maxillipeds) of the zoeae have a reduced number of setae and spines (or is absent in some individuals), and the foregut, under developed, have few minute setae in the cardiac and pyloric chambers. In contrast, after the metamorphosis into megalopa stage, all feeding appendages have many setae and, the foregut shows a well-developed gastric mill with strong lateral teeth. In the juvenile stage occurs an increase of setae and spines in the mouthparts and the foregut becomes more specialized. These observations strongly suggest that a lecithotrophic development occurs during all zoeal stages but the megalopa and juvenile stages are feeding animals. The functional morphology of the feeding structures of L. siriboia and other decapods will be briefly discussed.

The morphology of the foregut of larvae and postlarva of Sesarma curacaoense De Man, 1892: a species with facultative lecithotrophy during larval development

Previous study on the resistance of larvae of Sesarma curacaoense submitted to starvation has revealed a facultative lecithotrophy during zoeal stages, but megalopa and first juvenile stages are exclusively feeding stages. In the present study, the gross morphology and fine structure of the foregut of S. curacaoense were investigated during larval, megalopa and first juvenile stages. The foregut of the zoea I show specific setae and a filter press apparently functional. The foregut undergoes changes in the zoea II (last larval stage) with increment of setae number, mainly on the cardiopyloric valve and complexity of the filter press. After metamorphosis to megalopa stage the foregut become rather complex, with a gastric mill supporting a medial and two lateral teeth well-developed. The foregut of the first juvenile is more specialized compared to the previous stage, showing similar characteristics of the decapod adults. These results provide further evidence of facultative lecithotrophic development in the larvae of S. curacaoense.

Five egg-laying queens in a single colony of brazilian stingless bees (Melipona scutellaris Latreille

Polygyny, characterized by the presence of several egg-laying queens, is considered as a temporary colony status. In stingless bees it is rarely observed. This paper reports the first case of natural polygyny in Melipona scutellaris colony, with five egg-laying queens.