Further observations on clinical, histopathological, and immunological features of borderline disseminated cutaneous leishmaniasis caused by Leishmania (Leishmania) amazonensis

Leishmania (Leishmania) amazonensis has for some time been considered as the causative agent of two distinct forms of American cutaneous leishmaniasis (ACL): localized cutaneous leishmaniasis (LCL), and anergic diffuse cutaneous leishmaniasis (ADCL). Recently, a new intermediate form of disease, borderline disseminated cutaneous leishmaniasis (BDCL), was introduced into the clinical spectrum of ACL caused by this parasite, and in this paper we record the clinical, histopathological, and immunological features of eight more BDCL patients from Brazilian Amazonia, who acquired the disease in the Pará state, North Brazil. Seven of them had infections of one to two years' evolution and presented with primary skin lesions and the occurrence of metastases at periods varying from six to 12 months following appearance of the first lesion. Primary skin lesions ranged from 1-3 in number, and all had the aspect of an erythematous, infiltrated plaque, variously located on the head, arms or legs. There was lymphatic dissemination of infection, with lymph node enlargement in seven of the cases, and the delayed hypersensitivity skin-test (DTH) was negative in all eight patients prior to their treatment. After that, there was a conversion of DTH to positive in five cases re-examined. The major histopathological feature was a dermal mononuclear infiltration, with a predominance of heavily parasitized and vacuolated macrophages, together with lymphocytes and plasma cells. In one case, with similar histopathology, the patient had acquired his infection seven years previously and he presented with the largest number of disseminated cutaneous lesions. BDCL shows clinical and histopathological features which are different from those of both LCL and ADCL, and there is a good prognosis of cure which is generally not so in the case of frank ADCL.

Taxonomic revision of phlebotomine sand fly species in the series davisi and panamensis of the subgenus Psychodopygus Mangabeira, 1941 (Diptera: Psychodidae: Phlebotominae)

Several species of the subgenus Psychodopygus Mangabeira, 1941 are known to be leishmaniosis vectors in Brazil. Some of them are morphologically similar, which makes their identification quite difficult concerning epidemiological studies. The aim of the current work is to study the morphology of adult specimens of the subgenus Psychodopygus, in accordance with the morphological similarity and still taking into account the epidemiological importance of some species. Thus 11 species have been studied, including four subspecies of adult specimens deposited in the phlebotomine collection of Centro de Pesquisas René Rachou-Fiocruz. Morphological characters found in the literature and new features observed in this study were recorded in a taxonomic discussion format. These characters make it easy to separate such species. Four taxa, previously considered as subspecies, were raised to the category of species.

Morphological studies in a model for dengue-2 virus infection in mice

One of the main difficulties in studying dengue virus infection in humans and in developing a vaccine is the absence of a suitable animal model which develops the full spectrum of dengue fever, dengue haemorrhagic fever, and dengue shock syndrome. It is our proposal to present morphological aspects of an animal model which shows many similarities with the dengue infection in humans. BALB/c mice were intraperitoneally infected with non-neuroadapted dengue virus serotype 2 (DENV-2). Histopathological and morphometrical analyses of liver tissue revealed focal alterations along the infection, reaching wide-ranging portal and centrolobular veins congestion and sinusoidal cell death. Additional ultrastructural observations demonstrated multifocal endothelial injury, platelet recruitment, and alterated hepatocytes. Dengue virus antigen was detected in hepatocytes and in the capillar endothelium of the central lobular vein area. Liver function tests showed high levels of aspartate transaminase and alanine transaminase enzyme activity. Lung tissue showed interstitial pneumonia and mononuclear cells, interseptal oedema, hyperplasia, and hypertrophy of the bronchiolar epithelial cells. DENV-2 led to a transient inflammatory process, but caused focal alterations of the blood-exchange barrier. Viremia was observed from 2nd to 11th day p.i. by isolation of DENV-2 in C6/36 mosquito cell line inoculated with the supernatant of macerated liver, lung, kidney, and cerebellum tissues of the infected mice.

Development of Schistosoma mansoni worms in mice analyzed by bright field and confocal microscopy

The blood flukes of mammals (Digenea: Schistosomatidae) are among trematodes unique whose adult worms have separeted sexes which are dissimilar in appearance. The developmental features, growth and organogenesis of Schistosoma mansoni were studied in Swiss Webster mice by a digital system for image analysis and confocal microscopy. Data so far obtained showed two phases with significative morphological changes at 3-4 weeks post-infection, and a gradual similar development onwards in the reproductive system and tegument. Our male-dependent phase demonstrated that mating occurs before sexual maturing. At week three, the majority of male worms (59%) had formed the gynaecophoric canal although testicular lobes and tegumental tubercles were absent. By this time, 33% females had an incipient ovary (without cellular differentiation). At week four, 77.2% males presented testicular lobes with few germinative cells while 26% had developing tegumental tubercles. The immature ovary was observed in 69% females. Suckers followed different pattern of growth between male and females. The size of oral and ventral suckers from six-week-old male worms grew abruptly (3.0 fold) more than that of three-week-old. In female worms, maximum growth was attained at week four, reducing in size thereafter. From sixth week onwards, all specimens showed the fully developed reproductive system. Probably, these features are morphological traits which schistosome has experienced from hermaphrodite to dioecy.

Comparison between morphological and staining characteristics of live and dead eggs of Schistosoma mansoni

Schistosoma mansoni eggs are classified, according to morphological characteristics, as follows: viable mature and immature eggs; dead mature and immature eggs, shells and granulomas. The scope of this study was to compare the staining characteristics of different morphological types of eggs in the presence of fluorescent labels and vital dyes, aiming at differentiating live and dead eggs. The eggs were obtained from the intestines of infected mice, and put into saline 0.85%. The fluorescent labels were Hoechst 33258 and Acridine Orange + Ethidium Bromide and vital dyes (Trypan Blue 0.4% and Neutral Red 1%). When labelled with the probe Hoechst 33258, some immature eggs, morphologically considered viable, presented fluorescence (a staining characteristic detected only in dead eggs); mature eggs did not present fluorescence, and the other types of dead eggs, morphologically defined, showed fluorescence. As far as Acridine Orange + Ethidium Bromide are concerned, either the eggs considered to be live, or the dead ones, presented staining with green color, and only the hatched and motionless miracidium was stained with an orange color. Trypan Blue was not able to stain the eggs, considered to be dead but only dead miracidia which had emerged out of the shell. Neutral Red stained both live and dead eggs. Only the fluorescent Hoechst 33258 can be considered a useful tool for differentiation between dead and live eggs.

Re-mapping the molecular features of the human immunodeficiency virus type 1 and human T-cell lymphotropic virus type 1 Brazilian sequences using a bioinformatics unit established in Salvador, Bahia, Brazil, to give support to the viral epidemiology studies

The analysis of genetic data for human immunodeficiency virus type 1 (HIV-1) and human T-cell lymphotropic virus type 1 (HTLV-1) is essential to improve treatment and public health strategies as well as to select strains for vaccine programs. However, the analysis of large quantities of genetic data requires collaborative efforts in bioinformatics, computer biology, molecular biology, evolution, and medical science. The objective of this study was to review and improve the molecular epidemiology of HIV-1 and HTLV-1 viruses isolated in Brazil using bioinformatic tools available in the Laboratório Avançado de Sáude Pública (Lasp) bioinformatics unit. The analysis of HIV-1 isolates confirmed a heterogeneous distribution of the viral genotypes circulating in the country. The Brazilian HIV-1 epidemic is characterized by the presence of multiple subtypes (B, F1, C) and B/F1 recombinant virus while, on the other hand, most of the HTLV-1 sequences were classified as Transcontinental subgroup of the Cosmopolitan subtype. Despite the high variation among HIV-1 subtypes, protein glycosylation and phosphorylation domains were conserved in the pol, gag, and env genes of the Brazilian HIV-1 strains suggesting constraints in the HIV-1 evolution process. As expected, the functional protein sites were highly conservative in the HTLV-1 env gene sequences. Furthermore, the presence of these functional sites in HIV-1 and HTLV-1 strains could help in the development of vaccines that pre-empt the viral escape process.

Cladistic analysis of the subgenus Anopheles (Anopheles) Meigen (Diptera: Culicidae) based on morphological characters

In the present study, we used morphological characters to estimate phylogenetic relationships among members of the subgenus Anopheles Meigen. Phylogenetic analyses were carried out for 36 species of Anopheles (Anopheles). An. (Stethomyia) kompi Edwards, An. (Lophopodomyia) gilesi (Peryassú), Bironella hollandi Taylor, An. (Nyssorhynchus) oswaldoi (Peryassú) and An. (Cellia) maculatus Theobald were employed as outgroups. One hundred one characters of the external morphology of the adult male, adult female, fourth-instar larva, and pupa were scored and analyzed under the parsimony criterion in PAUP. Phylogenetic relationships among the series and several species informal groups of Anopheles (Anopheles) were hypothesized. The results suggest that Anopheles (Anopheles) is monophyletic. Additionally, most species groups included in the analysis were demonstrated to be monophyletic.

Morphological analysis of three populations of Anopheles (Nyssorhynchus) nuneztovari Gabaldón (Diptera: Culicidae) from Colombia

Based on the results of comparative analyses of 1,039 specimens of several progenies of Anopheles nuneztovarifrom three localities in Colombia, eight costal wing spot patterns were observed. Patterns I and III were the most frequent: 77.96% and 11.36%, respectively. Using the diagnostic characters ratio of the length of the basal dark area of hind tarsomere II/length of hind tarsomere II, ratio of the length of the humeral pale spot/length of the pre-humeral dark spot, and the ratio of the length of the subcostal pale spot/length of the distal sector dark spot (DS-III2/Ta-III2, HP/PHD, SCP/DSD) approximately 5% of the adult females were misidentified as a species of Nyssorhynchus, different from An. nuneztovari. Approximately 5% of the specimens showed DS-III2/Ta-III2 ratio less than 0.25 (range 0.21 - 0.24), and among them 3.34% shared a HP/PHD ratio less than 1.50. Consequently, 1.52% of An. nuneztovari individuals can be misidentified as Anopheles oswaldoi. In those specimens with the DS-III2/Ta-III2 ratios higher than 0.25, 34.45% displayed SCP/DSD values greater than 0.50 and of these, 3.65% displayed HP/PHD values greater than 1.8. This combination of characters could lead one to misidentify samples of An. nuneztovari as Anopheles rangeli. Similarly, 2.43% of the females could be identified erroneously as either Anopheles aquasalis or Anopheles benarrochi. Individuals with a HP/PHD ratio greater than 2.0, could be misidentified as Anopheles trinkae, Anopheles strodei or Anopheles evansae. A distinct combination of diagnostic characters for An. nuneztovari from Colombia is proposed.

Molecular and morphological characterization of heterorhabditid entomopathogenic nematodes from the tropical rainforest in Brazil

Despite massive losses of primary forest, the Amazonian rainforest remains an extremely rich source of biodiversity. In recent years, entomopathogenic nematodes (EPNs) have been isolated from soil in various parts of the world and used successfully as biological control agents against numerous insect pests. Therefore, a sampling in the rainforest of Monte Negro, Rondônia, Brazil was conducted with the aim of discovering new strains and/or species of EPNs for future development as biological control agents. From 156 soil samples taken at nine collecting sites, 19 isolates were obtained, all of them belonging to the genus Heterorhabditis. Four strains were subjected to detailed morphological and molecular evaluation. Based on morphometrics and internal transcribed spacer (ITS) sequence data, the strains LPP1, LPP2 and LPP4 were identified as Heterorhabditis indica, whereas LPP7 was considered Heterorhabditis baujardi. Comparative analysis of the ITS1 sequence of H. indica and H. baujardi isolates showed a polymorphic site for the restriction enzyme Tth 111 that could be used to distinguish the two species. Consequently, strains LPP1, LPP2, LPP3, LPP4, and LPP9 were identified as H. indica, whereas LPP5, LPP7, LPP8 and LPP10 were identified as H. baujardi.

Human bartonellosis: seroepidemiological and clinical features with an emphasis on data from Brazil - A review

Bartonellae are fastidious Gram-negative bacteria that are widespread in nature with several animal reservoirs (mainly cats, dogs, and rodents) and insect vectors (mainly fleas, sandflies, and human lice). Thirteen species or subspecies of Bartonella have been recognized as agents causing human disease, including B. bacilliformis, B. quintana, B. vinsonii berkhoffii, B. henselae, B. elizabethae, B. grahamii, B. washoensis, B. koehlerae, B. rocha-limaea, and B. tamiae. The clinical spectrum of infection includes lymphadenopathy, fever of unknown origin, endocarditis, neurological and ophthalmological syndromes, Carrion's disease, and others. This review provides updated information on clinical manifestations and seroepidemiological studies with an emphasis on data available from Brazil.

Morphological and functional characterizations of Schwann cells stimulated with Mycobacterium leprae

Nerve damage, a characteristic of leprosy, is the cause of patient deformities and a consequence of Schwann cells (SC) infection by Mycobacterium leprae. Although function/dysfunction of SC in human diseases like leprosy is difficult to study, many in vitro models, including SC lines derived from rat and/or human Schwannomas, have been employed. ST88-14 is one of the cell lineages used by many researchers as a model for M. leprae/SC interaction. However, it is necessary to establish the values and limitations of the generated data on the effects of M. leprae in these SC. After evaluating the cell line phenotype in the present study, it is close to non-myelinating SC, making this lineage an ideal model for M. leprae/SC interaction. It was also observed that both M. leprae and PGL-1, a mycobacterial cell-wall component, induced low levels of apoptosis in ST88-14 by a mechanism independent of Bcl-2 family members.

Some features of primary and recrudescent amodiaquine-resistant Plasmodium falciparum infections in Nigerian children

Characteristics of primary and recrudescent Plasmodium falciparum infections were evaluated in 25 children who did not recover after amodiaquine (AQ) treatment. Recrudescence was detected by a thick blood smear and confirmed by polymerase chain reaction. Over half of recrudescent events occurred after 14 days of initiation of treatment and were associated with relatively low asexual parasitaemia. We examined the gametocyte sex ratio (GSR) in these children and in age and gender-matched controls that had AQ-sensitive (AQ-S) infections (n = 50). In both AQ-S and AQ-resistant (AQ-R) infections, the GSR was female-biased pre-treatment and became male-biased by the third day after treatment initiation. However, gametocyte males persisted after this period in children with AQ-R infections. AQ-recrudescent infections are relatively low (25 of 612.4%) in children from this endemic area.

Morphological and biochemical characterization of the aetiological agents of white piedra

The Trichosporon genus is constituted by many species, of which Trichosporon ovoides and Trichosporon inkin are the causative agents of white piedra. They can cause nodules in genital hair or on the scalp. At present, Brazilian laboratory routines generally do not include the identification of the species of Trichosporon genus, which, although morphologically and physiologically distinct, present many similarities, making the identification difficult. The aim of this study was to identify the aetiological agents at the species level of white piedra from clinical specimens. Therefore, both the macro and micro morphology were studied, and physiological tests were performed. Trichosporon spp. was isolated from 10 clinical samples; T. ovoides was predominant, as it was found in seven samples, while T. inkin was identified just in two samples. One isolate could not be identified at the species level. T. inkin was identified for the first time as a white piedra agent in the hair shaft on child under the age of 10.

Microbiological and host features associated with corynebacteriosis in cancer patients: a five-year study

During a five-year period, 932 clinical isolates from cancer patients treated in a Brazilian reference centre were identified as corynebacteria; 86% of the cultures came from patients who had been clinically and microbiologically classified as infected and 77.1% of these patients had been hospitalised (71.1% from surgical wards). The adult solid tumour was the most common underlying malignant disease (66.7%). The univariate and multivariate analyses showed that hospitalised patients had a six-fold greater risk (OR = 5.5, 95% CI = 1.15-26.30 p = 0.033) related to 30-day mortality. The predominant species were Corynebacterium amycolatum (44.7%), Corynebacterium minutissimum (18.3%) and Corynebacterium pseudodiphtheriticum (8.5%). The upper urinary tracts, surgical wounds, lower respiratory tracts, ulcerated tumours and indwelling venous catheters were the most frequent sources of C. amycolatum strains. Corynebacterium jeikeium infection occurred primarily in neutropenic patients who have used venous catheters, while infection caused by C. amycolatum and other species emerged mainly in patients with solid tumours.

Comparative descriptions of eggs from three species of Rhodnius (Hemiptera: Reduviidae: Triatominae)

The authors describe and compare the morphological and ultrastructural characteristics of eggs from the three most recent described species of the genus Rhodnius Stål, 1859, which have not previously been studied. These species are Rhodnius colombiensis (Mejia, Galvão & Jurberg 1999), Rhodnius milesi (Carcavallo, Rocha, Galvão & Jurberg 2001) and Rhodnius stali (Lent, Jurberg & Galvão 1993). The results revealed that there are similarities in the exochorial architecture of optical microscopy and scanning electron microscopy; these include the predominance of hexagonal cells that are common to all Rhodnius species and variable degrees of lateral flattening, which is common not only to species of this genus, but also to the Rhodniini tribe. Differences in overall colour, the presence of a collar in R. milesi, a longitudinal bevel in R. stali and the precise length of R. colombiensis can be useful distinguishing features. As a result of this study, the key for egg identification proposed by Barata in 1981 can be updated.