Anticorpos antileucotoxina contra Actinobacillus actinomycetemcomitans em amostras de soro e saliva de pacientes com periodontite juvenil localizada

The leukotoxin produced by Actinobacillus actinomycetemcomitans is considered the major virulence factor with potential to cause damage to the host defenses. The present work analyzed the serumal and salivary levels of antibodies against the leukotoxin produced by A. Actinomycetemcomitans, in patients with Localized Juvenile Periodontitis (LJP) and in healthy controls. Additionally, analysis of the immune complex (IC) was carried out in saliva samples . The classic ELISA method, with leukotoxin obtained through Sephadex G-200 gel filtration, and the capture ELISA method, using rabbit anti-A. Actinomycetemcomitans (leucotoxic, FDC Y4, IgG) adsorbed with a non-leukotoxic strain of A. actinomycetemcomitans, were used. The results obtained demonstrated significantly higher serumal levels of IgG in patients with LJP, when they were compared with the healthy controls, both for the classic and capture ELISA methods (p < 0.05). However, no significant differences were observed between the salivary levels of IgG, SIgA and IC in the examined individuals. These results suggest that even though A. actinomycetemcomitans presents virulence factors that affect the immune response, there is immune response to leukotoxin in LJP patients. This increase of IgG in the blood stream might contribute to host defense, limiting the lesion to the periodontal regions already colonized by A. actinomycetemcomitans.A leucotoxina de Actinobacillus actinomycetemcomitans é considerada seu principal fator de virulência com potencial de causar agressão às defesas do hospedeiro. No presente trabalho, foram analisados os níveis séricos e salivares de anticorpos antileucotoxina de A. actinomycetemcomitans em soros e salivas de pacientes com periodontite juvenil localizada (PJL) e controles saudáveis. Adicionalmente, foi realizada a análise de complexo imune (CI) nas amostras de saliva. Foram utilizados os métodos ELISA clássico com a leucotoxina obtida por gel filtração em Sephadex G-200 e ELISA de captura utilizando IgG de coelho anti-A. actinomycetemcomitans FDC Y4 leucotóxico adsorvido com uma cepa da mesma espécie, porém, não leucotóxica. Os resultados obtidos demonstraram níveis séricos de IgG significativamente mais elevados em pacientes com PJL em relação aos controles sadios, tanto por ELISA clássico como por ELISA de captura (p < 0,05). No entanto, não foram observadas diferenças entre os níveis de IgG, IgA-S e CI nas salivas dos indivíduos examinados. Estes resultados sugerem que, embora A. actinomycetemcomitans apresente vários fatores de virulência que afetam a resposta imune do hospedeiro, ocorre resposta imune à leucotoxina nos pacientes com PJL. Esse aumento de IgG na circulação sangüínea pode contribuir na defesa do hospedeiro, limitando a lesão nas regiões periodontais amplamente colonizadas por A. actinomycetemcomitans

Ecologia do Bacillus thuringiensis num Latossolo

Bacillus thuringiensis is a Gram positive, sporangial bacterium, known for its insecticidal habilities. Survival and conjugation ability of B. thuringiensis strains were investigated; vegetative cells were evaluated in non-sterile soil. Vegetative cells decreased rapidly in number, and after 48 hours the population was predominantly spores. No plasmid transfer was observed in non-sterile soil, probably because the cells died and the remaining cells sporulated quickly. Soil is not a favorable environment for B. thuringiensis multiplication and conjugation. The fate of purified B. thuringiensis toxin was analyzed by extractable toxin quantification using ELISA. The extractable toxin probably declined due to binding on surface-active particles in the soil.O comportamento de células vegetativas do Bacillus thuringiensis foi estudado em solo não esterilizado. Após o inóculo grande parte das células morrem e o restante esporula em 24 horas. Não foi observada conjugação provavelmente porque poucas células sobrevivem no solo e rapidamente esporulam, mostrando que este não é o ambiente propício para a multiplicação e conjugação desta bactéria. A toxina purificada, portanto livre de células, diminui rapidamente sua quantidade em solo não esterilizado. Provavelmente a ligação da toxina na fração argilosa do solo é a principal responsável por este fenômeno

Candida albicans

Genotypes of Candida spp. isolated from exhalation of 20 dolphins, 11 water samples from captive pools, and 24 oral cavities of staff members in an aquarium using a combination of multiple drug resistance 1 gene (MDR1) and the internal transcribed spacer (ITS) 1 5.8s-ITS 2 regions of ribosomal RNA gene (ITS rDNA) sequences were studied. The holding ratios of the dolphins, captive pools, and staff members were 70, 90, and 29%, respectively. Isolated pathogenic yeast species common to the dolphins and environments were Candida albicans and C. tropicalis. Identical genotypes in both Candida spp. based on the combination of MDR1 and ITSrDNA were found in some dolphins, between a dolphin and a staff, among dolphins and environments, and among environments. The results indicated the diffusion and exchange of pathogenic yeasts at the aquarium among dolphins and environments. The isolates at the aquarium showed higher rates of resistance to azole antifungals compared to reference isolates

Humoral immune response in experimental ddY mice Paracoccidioidomycosis

A paracoccidioidomicose (PCM) é uma micose sistêmica, restrita à América Latina, com maior incidência no Brasil. O camundongo ddY tem sido empregado como modelo murino de PCM e, no entanto, não há informações a respeito da resposta imune desse animal frente à infecção. O presente estudo tem como objetivo avaliar a resposta imune humoral específica para o principal antígeno, gp43, do fungo Paracoccidioides brasiliensis, em camundongos ddY infectados com a cepa virulenta Pb 18. Foram realizadas análises da antigenemia e histopatológico em vários órgãos e em diferentes tempos pós-infecção. Os resultados obtidos demonstraram aumento nos níveis de IgG anti-gp43 nos dias 14, 17, 21, 24, 28 e 56 pós-infecção e aumento no nível de gp43 solúvel aos 28 dias pós-infecção. As células fúngicas foram detectadas em todos os órgãos analisados (cérebro, coração, pulmão, fígado, baço e rim) e em todos os períodos. As lesões granulomatosas tornaramse predominantes 14 dias pós-infecção. Os resultados evidenciaram que o camundongo ddY produz resposta imune humoral frente ao principal antígeno de P. brasiliensis, apresentando-se elevado até 56 dias pósinfecção. A redução do nível de gp43 solúvel na fase crônica, supostamente devido ao início do controle da infecção, requer estudos complementares adicionais.Paracoccidioidomycosis (PCM) is a systemic mycosis, restrict to Latin America, with higher incidence in Brazil. ddY mice have been used as experimental PCM model, although there is no data regarding immune response. The aim of the present study was evaluated specific humoral response against the main specific antigen of the fungal Paracoccidioides brasiliensis, the gp43, in ddY mice infected with virulent Pb 18. Antigenemia analysis and histophatological exam in several organs were performed in different time postinfection The results showed increased levels of anti-gp43 IgG on days 14, 17, 21, 24, 28 and 56 post-infection and increased levels of soluble gp-43 on day 28 post-infection. The fungal cells were detected in all organs analyzed (brain, heart, lung, liver, spleen and kidney) in all investigated periods. The granulomatous lesions became predominant 14 days after infection. The results evidence that ddY mice produce humoral immune response to main P. brasiliensis antigen, with high levels until 56 days after infection. Further studies are needed to show that reduction of soluble gp43 in chronic phase correlates with infection control

Detection of antibodies to Paracoccidioides brasiliensis in horses from northern Region of Parana State

Paracoccidioidomycosis, caused by the dimorphic fungus Paracoccidioides brasiliensis, is the most prevalent human systemic mycosis in Latin America. Paracoccidioidomycosis affects mainly male rural workers, causing granulomatous lesions in organs such as lungs, liver and spleen. The participation of other animal species in the fungus eco-epiderniology in not well understood. The aim of this study was to evaluate the infection by P. brasiliensis in horses from the Northern Region of Parana State. The serum samples from 100 horses were assayed by ELISA and Immunodiffusion test, using gp43 and exoantigen as antigens, respectively. A seropositivity of 30% was observed by ELISA test, although all samples were negative by immunodiffusion test. These results suggest that horses can be indicator of fungus presence in the ambient.Univ Estadual Londrina, Dept Ciencias Patol, Londrina, BrazilUniv Estadual Londrina, Dept Vet Prevent Med, Londrina, PR, BrazilUniv Fed Sao Paulo, Dept Microbiol Imunol & Parasitol, Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Microbiol Imunol & Parasitol, Sao Paulo, BrazilWeb of Scienc

Ecological aspects of Bacillus thuringiensis in an Oxisol Ecologia do Bacillus thuringiensis num Latossolo

Bacillus thuringiensis is a Gram positive, sporangial bacterium, known for its insecticidal habilities. Survival and conjugation ability of B. thuringiensis strains were investigated; vegetative cells were evaluated in non-sterile soil. Vegetative cells decreased rapidly in number, and after 48 hours the population was predominantly spores. No plasmid transfer was observed in non-sterile soil, probably because the cells died and the remaining cells sporulated quickly. Soil is not a favorable environment for B. thuringiensis multiplication and conjugation. The fate of purified B. thuringiensis toxin was analyzed by extractable toxin quantification using ELISA. The extractable toxin probably declined due to binding on surface-active particles in the soil.<br>O comportamento de células vegetativas do Bacillus thuringiensis foi estudado em solo não esterilizado. Após o inóculo grande parte das células morrem e o restante esporula em 24 horas. Não foi observada conjugação provavelmente porque poucas células sobrevivem no solo e rapidamente esporulam, mostrando que este não é o ambiente propício para a multiplicação e conjugação desta bactéria. A toxina purificada, portanto livre de células, diminui rapidamente sua quantidade em solo não esterilizado. Provavelmente a ligação da toxina na fração argilosa do solo é a principal responsável por este fenômeno