Classification of varieties of pasteurella pestis strains isolated in the interior of the state of Pernambuco-Brazil

Studies were made on the biochemical behavior of 100 strains of P.pestis isolated in Northeastern Brazil with regard to production of nitrous acid, reduction of nitrates to nitrltes, and aciáification of glycerol. Results showed that 98 strains can be classified as "orientalis variety", while the remaining two could not be included in any of the existing "varieties".

Storage of organochlorine inseticides in hepatosplenic schistosomiasis

This paper reports on the findings of a survey on OCI storage in people in Bahia, Brasil. In this survey 11 samples of adipose tissue were taken from people who underwent splenectomy for hepato splenic schistosomiasis. In these patients, total DDT averaged 10.66 ppm as compared to 4,83 ppm of total DDT found in presumably healthy people. The difference was statistically significant. It is considered that the increased DDT storage in patients with hepatosplenic schistosomiass may be the result of a reduced metabolzation of p,p'-DDT and reduced excretion of its metabolites. Another possíbility is the increased exposure to organochlorine nsectedes by hepatosplenc patients who frequently come from irrigation zones, where these compounds are more used in intensive cultivatíon.

Effects of lethal and non-lethal malaria on the mononuclear phagocyte system

The effects ofone non-lethal species ofmalarialparasite, Plasmodium yoelii, and one lethal species, P. berghei, on the mononuclear phagocyte system (MPS) of BALB/c mice were studied. P. yoelii caused a greater and more sustained expansion and activation of the MPS, and the two major populations of spleen phagocytic cells-red pulp and marginal zone macrophages - exhibited a greater increase in numbers in this infection. During the course of P. berghei mataria, the spleen was progressively occupied by haematopoietic tissue and, at the terminal stage of infection, an extensive depletion of lymphocytes and macrophages was apparent. The possibility was suggested that the outcome of mataria may be inftuenced by the particular way the parasite interacts with the MPS.

Sensitivity of Gomez-Nuñez boxes for the detection of household infestation with Panstrongylus megistus

Four methods for detecting household infestations with Panstrongylus megistus were compared: 1) manual collection; 2) collection after pyrethrum application; 3) search viable eggs; and 4) Gomez-Nuñez boxes. Manual collection was the most sensitive method (23% infested), followed by pyrethrum (21%), Gomez-Nuñez boxes (15%) and viable eggs (12%). About 10% of infested houses were positive exclusively on the Gomez-Nuñez box test. More over, 6 out of the 7 houses positive exclusively on the Gomez-Nuñez method were located in a recently sprayed area, where P. megistus density was low. Inspection of Gomez-Nuñez boxes at 12 weekspost-application was twice as effective as inspection at 6 weekspost-application. Triatomine feces was the most common evidencefor thepresence of P. megistus found within Gomez-Nuñez boxes. Gomez-Nuñez boxes area a useful adjunct to manual collection in detecting domestic infestations with P. megistus, especially in areas where bug densities are low. However, the utility of Gomez-Nuhez boxes must be weighed against the time and labor they require.

Production of chitin-glucan complex by Pichia pastoris

Dissertation for the Degree of Master in Biotechnology

Production of bacterial biopolymers from industrial fat-containing wastes

Dissertation presented in partial fulfilment of the Requirements for the Degree of Master in Biotechnology

Angiostrongylus costaricensis and the intermediate hosts: observations on elimination of L3 in the mucus and inoculation of L1 through the tegument of mollucs

Human accidental infection with Angiostrongylus costaricensis may result in abdominal disease of varied severity. Slugs from the Veronicellidae family are the main intermediate hosts for this parasitic nematode of rodents. Phyllocaulis variegatus, Phyllocaulis soleiformis and Phyllocaulis boraceiensis were experimentally infected to describe the kinetics of L3 elimination in the mucus secretions of those veronicelid species. A maximum of 2 L3/g/day was found in the mucus, while the number of L3 isolated from the fibromuscular tissues varied from 14 to 448. Productive infection was established by inoculations in the hyponotum or in the body cavity, through the tegument. Intra-cavity injection is a less complex procedure and permits a better control of inocula. A preliminary trial to titrate the infective dosis for P. variegatus indicated that inocula should range between 1000 and 5000 L1. The data also confirmed the importance of P. variegatus as an intermediate host of A. costaricensis.

Study on the valorization routes of ashes from thermoelectric power plants working under mono-and co-combustion regimes

Thesis submitted to obtain the Doctoral degree in Energy and Bioenergy

Description of a possible clonal expansion of Plasmodium vivax in Manaus - Amazonas - Brazil

Atypical P. vivax cases reported in Manaus municipality led us to detect a genetic isolate of P. vivax. Variable regions of SSUrRNA were examined from the initial time of infection and in the two recrudescences/relapses from a patient exhibiting chloroquine and primaquine resistance. A unique isolate, found at all stages of infection, suggests the presence of a clonal expansion.

Genetic diversity and differentiation in natural Plasmodium falciparum populations inferred by molecular typing of the merozoite surface proteins 1 and 2

Genetic diversity and differentiation, inferred by typing the polymorphic genes coding for the merozoite surface proteins 1 (Msp-1) and 2 (Msp-2), were compared for 345 isolates belonging to seven Plasmodium falciparum populations from three continents. Both loci yielded similar estimates of genetic diversity for each population, but rather different patterns of between-population differentiation, suggesting that natural selection on these loci, rather than the transmission dynamics of P. falciparum, determines the variation in allele frequencies among populations.

High molecular mass fraction in clinical isolates of Paracoccidioides brasiliensis

INTRODUCTION: Different serum levels of the IgG/IgE for Paracoccidioides brasiliensis high mass molecular (hMM) fraction (~366kDa) in the acute and chronic forms of the disease have been reported. Considering the nonexistence of hMM fraction investigation involving clinical isolates of P. brasiliensis, the present study aimed to investigate the presence of the hMM fraction (~366kDa) in cell free antigens (CFA) from P. brasiliensis clinical isolates. METHODS: CFA from 10 clinical isolates and a reference strain (Pb18) were submitted to SDS-polyacrylamide gel electrophoresis (SDS-PAGE) followed by gel image capturing and densitometer analysis. Additionally, CFA from 20 isolates and Pb18 were analyzed by capture ELISA (cELISA) using polyclonal (polAb) or monoclonal (mAb) antibodies to the hMM fraction. RESULTS: The presence of the hMM component was observed in CFA of all samples analyzed by SDS-PAGE/densitometry and by cELISA. In addition, Pearson's correlation test demonstrated stronger coefficients between hMM fraction levels using pAb and mAb (R = 0.853) in cELISA. CONCLUSIONS: The soluble hMM fraction was present in all the P. brasiliensis clinical isolates analyzed and the reference strain Pb18, which could be used as a source of this antigen. The work also introduces for first time, the cELISA method for P. brasiliensis hMM fraction detection. Analysis also suggests that detection is viable using polAb or mAb and this methodology may be useful for future investigation of the soluble hMM fraction (~366kDa) in sera from PCM patients.

Occurrence of synanthropic triatomines (Hemiptera: Reduviidae) in the Federal District of Brazil

INTRODUCTION: Entomological surveillance of Chagas disease in the Federal District of Brazil (DF), has recorded the following triatomine species: Panstrongylus megistus, P. geniculatus, P. diasi, Rhodnius neglectus, Triatoma pseudomaculata, and T. sordida. We aimed to analyze the spatial and temporal occurrence of triatomine species collected in DF, and their indices of natural infection with trypanosomes. METHODS: The Health State Secretariat of DF recorded triatomines between 2002 and 2010 in 20 administrative regions. This retrospective analysis considered the number of adults and nymphs of each species collected and infected in both intradomicile and peridomicile. RESULTS: A total of 754 triatomines were collected in 252 reported domiciles. Panstrongylus megistus was the most frequent species (65%), followed by T. pseudomaculata (14%). Of the 309 examined insects, only 3 (1%) specimens of P. megistus were infected with flagellates morphologically similar to Trypanosoma cruzi. The spatial occurrence indicated a higher diversity of triatomines and frequency of T. sordida in rural areas. Moreover, there was a predominance of P. megistus in urban areas. The number of records of P. megistus in the rainy season was two times higher than that during the dry season. The largest number of triatomines was collected in November. CONCLUSIONS: The presence of P. megistus specimens infected with trypanosomes in domiciles, shows the potential risk of human infection in DF. Thus, it is essential to continue entomological surveillance, intensifying it in the rainy season and in regions of greater occurrence.

Phenotypic and molecular characterization of antimicrobial resistance and virulence factors in Pseudomonas aeruginosa clinical isolates from Recife, State of Pernambuco, Brazil

INTRODUCTION: The emergence of carbapenem resistance mechanisms in Pseudomonas aeruginosa has been outstanding due to the wide spectrum of antimicrobial degradation of these bacteria, reducing of therapeutic options. METHODS: Sixty-one clinical strains of P. aeruginosa isolated from five public hospitals in Recife, Pernambuco, Brazil, were examined between 2006 and 2010, aiming of evaluating the profiles of virulence, resistance to antimicrobials, presence of metallo-β-lactamase (MBL) genes, and clonal relationship among isolates. RESULTS: A high percentage of virulence factors (34.4% mucoid colonies; 70.5% pyocyanin; 93.4% gelatinase positives; and 72.1% hemolysin positive) and a high percentage of antimicrobial resistance rates (4.9% pan-resistant and 54.1% multi-drug resistant isolates) were observed. Among the 29 isolates resistant to imipenem and/or ceftazidime, 44.8% (13/29) were MBL producers by phenotypic evaluation, and of these, 46.2% (6/13) were positive for the blaSPM-1 gene. The blaIMP and blaVIM genes were not detected. The molecular typing revealed 21 molecular profiles of which seven were detected in distinct hospitals and periods. Among the six positive blaSPM-1 isolates, three presented the same clonal profile and were from the same hospital, whereas the other three presented different clonal profiles. CONCLUSIONS: These results revealed that P. aeruginosa is able to accumulate different resistance and virulence factors, making the treatment of infections difficult. The identification of blaSPM-1 genes and the dissemination of clones in different hospitals, indicate the need for stricter application of infection control measures in hospitals in Recife, Brazil, aiming at reducing costs and damages caused by P. aeruginosa infections.

The influence of carbohydrates in the interaction of Paracoccidioides brasiliensis with CCL-6 cells in vitro

INTRODUCTION: Little is known about the early events in the interaction between Paracoccidioides brasiliensis and its host. To understand the effect of carbohydrates in the interaction between the fungus and epithelial cell in culture, we analyzed the influence of different carbohydrate solutions on the adhesion of P. brasiliensis yeast cells to CCL-6 cells in culture. METHODS: Fungal cells were cultivated with the epithelial cell line, and different concentrations of D-fucose, N-acetyl-glucosamine, D-mannose, D-glucosamine, D-galactosamine, sorbitol and fructose were added at the beginning of the experiment. Six hours after the treatment, the cells were fixed and observed by light microscopy. The number of P. brasiliensis cells that were adhered to the CCL-6 monolayer was estimated. RESULTS: The number of adhesion events was diminished following treatments with D-fucose, N-acetyl-glucosamine, D-mannose, D-glucosamine and D-galactosamine as compared to the untreated controls. Sorbitol and fructose-treated cells had the same adhesion behavior as the observed in the control. P. brasiliensis propagules were treated with fluorescent lectins. The FITC-labeled lectins WGA and Con-A bound to P. brasiliensis yeast cells, while SBA and PNA did not. CONCLUSIONS: The perceptual of adhesion between P. brasiliensis and CCL-6 cells decreased with the use of D-mannose, N-acetyl-glucosamine and D-glucosamine. The assay using FITC-labeled lectins suggests the presence of N-acetyl-glucosamine, α-mannose and α-glucose on the P. brasiliensis cell surface. An enhanced knowledge of the mediators of adhesion on P. brasiliensis could be useful in the future for the development of more efficient and less harmful methods for disease treatment and control.

Efficacy of voriconazole in experimental rat paracoccidioidomycosis

INTRODUCTION: Amphotericin B, azole or sulfamide drugs are used for treatment of patients with paracoccidioidomycosis. Among the azole drugs, voriconazole was active in vitro against Paracoccidioides brasiliensis and showed efficacy in the treatment of patients infected with this fungus.In the present study the antifungal activity of voriconazole and of other drugs was compared in a rat model of paracoccidioidomycosis. METHODS: Wistar rats were inoculated intravenously with the BOAS strain of P. brasiliensis and antifungal drugs were administered to the animals by gavage at the following doses (mg/kg weight/day): voriconazole (5 to 20), ketoconazole (12 to 15), fluconazole (6), itraconazole (4), and sulfamethoxazole-trimethoprim (120 to 150). The antifungal activity of the drugs was assessed by determining the P. brasiliensis colony forming units in the lungs and spleen of the animals at the end of treatment and by a survival study. RESULTS: Voriconazole reduced the total tissue fungal burden of P. brasiliensis, particularly at doses of ≥10mg/kg weight/day but its antifungal activity was less intense than that of fluconazole, itraconazole and sulfamethoxazole-trimethoprim. The mean survival of animals treated with the last three drugs, 29.1±10.7, 26.1± 10.1 and 28.4±9.6 days, respectively, was higher than that achieved with voriconazole 10mg/kg weight/day (18.5±8.3 days) and that observed in untreated animals (15.7±3.6 days). CONCLUSIONS: At doses similar to those used for clinical treatment, voriconazole showed lower antifungal activity in experimental rat paracoccidioidomycosis than that obtained with itraconazole and sulfamethoxazole-trimethoprim.