Legionella pneumophila associada a insuficiência respiratória aguda: primeiro isolamento no Brasil

Relatam os autores isolamento de Legionella pneumophila sorogrupo 1, acompanhado de evidências sorológicas de infecção atual, em homem de 40 anos com infecção respiratória grave que evoluiu para insuficiência respiratória aguda. Esta foi caracterizada por hipoxemia severa refratária a altas concentrações de oxigênio e radiograficamente por infiltrados difusos em ambos pulmões. Com introdução de clindamicina, amicacina, ceftriaxone e ventilação à volume com Pressão Expiratória Positiva Final (PEEP) de 14 cm de H(2)0, houve estabilização do quadro e gradual recuperação. Suspeitando-se de legionelose, foi colhido sangue e secreção traqueal para exames específicos. A secreção traqueal foi semeada em meio BCYE com isolamento de bacilo gram-negativo, identificado como Legionella pneumophila sorogrupo 1 por características culturais, bioquímicas e reações de imunofluorescência direta e de aglutinação em lâmina. O estudo sorológico revelou títulos de anticorpos 128, 1024, 4096 e 8192 para amostras coletadas na 1ª, 3ª, 4ª e 6ª semanas após o início do quadro. Os resultados definitivos foram obtidos com o paciente em recuperação. É realçada a comprovação da presença de Legionella sp. como agente patológico em nosso meio; a importância das medidas de suporte na evolução do paciente; a necessidade de se pensar neste agente no diagnóstico diferencial de pneumonias e de se pesquisar mais esta etiologia com metodologia laboratorial específica.

Comparison of indirect immunofluorescence test for measles antibodies with haemagglutination inhibition and plaque neutralization tests

Indirect Immunofluorescence (IFA), Plaque Reduction Neutralization (PRN) and Haemagglutination Inhibition (HI) tests for measles antibodies were carried out in 197 sera obtained from umbilical cord and vaccinated children. The IFA was also applied to blood samples collected with filter paper. IFA results demonstrated that the test is relatively simple to perform, with good reproducibility for different antigen lots. Good correlation was obtained between IFA, PRN and HI antibody titers. Better correlation was demonstrated with IFA and PRN than with HI and PRN tests. Sensitivity of IFA in detecting antibody was less effective than PRN, however more effective than HI using rhesus monkey red blood cells. PRN antibody titers over 100 were detected by IFA but not by HI (9.7% with negative results). IFA may be of considerable practical use and able to substitute HI in Seroepidemiological surveys and to evaluate vaccine efficacy. It also can be simplified by employing filter paper collected samples.

Evaluation of different immunization protocols with P. brasiliensis antigens in Guinea pigs

The objective of the present study was to develop an efficient and reproducible protocol of immunization of guinea pigs with P. brasiliensis antigens as an animal model for future studies of protective immunity mechanisms. We tested three different antigens (particulate, soluble and combined) and six protocols in the presence and absence of Freund's complete adjuvant and with different numbers of immunizing doses and variable lenght of time between the last immunizing dose and challenge. The efficacy of the immunizing protocol was evaluated by measuring the humoral and cellular anti-P. brasiliensis immune response of the animals, using immuno-diffusion, skin test and macrophage migration inhibition test. It was observed that: 1. Three immunizing doses of the antigens induced a more marked response than two doses; 2. The highest immune response was obtained with the use of Freund's complete adjuvant; 3. Animals challenged a long time (week 6) after the last immunizing dose showed good anti-P. brasiliensis immune response; 4. The particulate antigen induced the lowest immune response. The soluble and the combined antigens were equally efficient in raising good humoral and cellular anti-P. brasiliensis immune response

Legionelose associada a pneumopatias em São Paulo: estudo da comprovação etiológica por isolamento e sorologia

A presença de Legionella sp como patógeno atuante em nosso país não fora bem documentada, embora a literatura refira a importância deste agente em grande número de países. O presente trabalho teve como objetivo a detecção do microrganismo ou evidenciar sua resposta imunológica em pacientes portadores de pneumopatias infecciosas na cidade de São Paulo. Para tanto foi introduzida metodologia laboratorial específica para o cultivo e identificação do agente e aplicada reação sorológica para verificação de níveis de anticorpos correspondentes. Foram estudados pacientes de 2 centros universitários em São Paulo, correspondentes a 100 do Hospital Universitário U.S.P. com pneumopatias infecciosas em geral e 100 do Hospital das Clínicas F.M.U.S.P. com pneumopatias infecciosas previamente selecionados para afastar outras etíologias bacterianas e dentre estes 30 pertencentes a Unidade de Transplante Renal. O material biológico destinado ao cultivo de Legionella sp foi constituído por: escarro, secreção traqueal, líquido pleural, lavado brônquico ou biópsia de tecido pulmonar. As tentativas de isolamento do agente foram realizadas em meio de BCYE com e sem antibióticos, a identificação das colônias, foram realizadas através de provas de crescimento em placas de BCYE sem cisteína, provas bioquímicas, imunofluorescência direta e soroaglutinação em lâmina. A pesquisa do agente em material biológico foi realizado pelo método de imunofluorescência direta. A pesquisa de anticorpos específicos para Legionella pneumophila sorogrupo 1 foi efetuada pela reação de imunofluorescência indireta. Procedeu-se ainda a estudo sorológico) nos comunicantes de pacientes com legionelose para evidenciar possível transmissão do agente. Em 2 casos obteve-se isolamento em cultura e em 4 casos, somente reação de imunofluorescência direta positiva para L. pneumophila sorogrupo 1, à partir do material biológico, representando um total de 6% entre pacientes da comunidade e hospitalares, comprovando desta forma a existência do agente entre nós. A reação sorológica de imunofluorescência indireta permitiu estabelecer infecção atual ou pregressa por Legionella pneumophila sorogrupo 1, em 16 dos 100 pacientes estudados no Hospital das Clínicas e em apenas 1 dos 100 pertencentes ao Hospital Universitário. Pacientes considerados como grupo de risco do Hospital das Clínicas correspondentes a transplantados renais mostraram evidências sorológicas de legionelose atual ou pregressa em 10 dos 30 estudados, isto é 33%, ficando com 8,5% para pacientes da comunidade, 6 dos 70 estudados, sendo 3 destes debilitados por doença sistêmica severa (4,28%). Nos profissionais de saúde comunicantes dos pacientes com legionelose internados no Hospital das Clínicas, apenas 1 em 28 revelou sorologia compatível com infecção pregressa, confirmando dados da literatura de não ser usual a transmissão de pessoa a pessoa

Esporotricose do gato doméstico (Felis catus): transmissão humana

No presente trabalho relata-se caso de paciente, funcionário de hospital veterinário, infectado através de arranhadura de gato doméstico portador de esporotricose. Inquérito domiciliar junto aos proprietários do animal fonte de infecção, revelou dois outros casos presuntivos de esporotricose humana transmitida por gatos, e confirmou o diagnóstico, por cultivo do Sporotrix schenckii, em 3 gatos domésticos adicionais. A esporotricose felina caracteriza-se por lesões cutâneas ulceradas e tendência à disseminação sistêmica e evolução fatal. A transmissão intra e inter-espécie é facilitada pela exuberância de fungos nas lesões cutâneas de felinos infectados.

Human lagochilascariasis treated sucessfully with ivermectin: a case report

A 15 year old male patient was diagnosed as being infected with the nematode Lagochilascaris minor, presenting as abscesses over the left mastoid region, and invading the temporal bone, mastoid sinuses and possibly the CNS. Surgical drainage and administration of cambendazole and levamisole led to improvement, followed by an early relapse and poor tolerance to the antihelminthic drugs. Repeated doses of ivermectin (an animal preparation) were used for the first time to treat this condition and resulted in complete remission of signs of infection, maintained for 15 months after the end of drug therapy, indicating cure of the disease.

Legionnaires' disease in the renal transplant unit of "Hospital das Clinicas, FMUSP": during a five year period (1988-1993)

Several reports have related Legionella pneumophila with pneumonia in renal transplant patients, however this association has not been systematically documented in Brazil. Therefore this paper reports the incidence, by serologycal assays, of Legionella pneumophila serogroup 1 in these patients during a five year period. For this purpose sera from blood samples of 70 hospitalized patients with pneumonia from the Renal Transplant Unit of Hospital das Clinicas, FMUSP collected at the acute and convalescent phase of infection were submitted to indirect immunofluorescence assay (IFA) to demonstrate anti-Legionella pneumophila serogroup 1 antibodies. Of these 70 patients studied during the period of 1988 to 1993,18 (25.71 %) had significant rises in specific antibody titers for Legionella pneumophila serogroup 1. Incidence was interrupted following Hospital water decontamination procedures, with recurrence of infections after treatment interruption. In this study, the high susceptibility (25.71%) of immunodepressed renal transplant patients to Legionella pneumophila serogroup 1 nosocomial infections is documented. The importance of the implementation and maintenance of water decontamination measures for prophylaxis of the infection is also clearly evident.

Dot-ELISA for the detection of IgM and IgG antibodies to Schistosoma mansoni worm and egg antigens, associated with egg excretion by patients

Human schistosomiasis, caused by Schistosoma mansoni, is highly prevalent in Brazil and usually diagnosed by time consuming stool analysis. Serological tests are of limited use in this disease, mainly for epidemiological studies, showing no discrimination between previous contact with the parasite and active infections. In the present study, we standardized and compared a Dot-ELISA for IgM and IgG antibodies against S. mansoni antigens from eggs and worms with a routine IgG and IgM immunofluorescence assay using similar antigens, in the study of sera from 27 patients who had quantified egg stool excretion. The positivity obtained for IgG Dot-ELISA was 96.3% and 88.9% for IgM Dot-ELISA with worm antigen and 92.6% and 90.9% with egg antigen. The IFI presented similar positivities using worm antigen, 92.6% (IgG) and 96.3% (IgM),and lower results with egg antigen, 77.8% (IgG and IgM). The patients studied were divided into two groups according to their egg excretion, with greater positivity of serological tests in higher egg excreters. When comparing the quantitative egg excretion and the serological titers of the patients, we detected a correlation only with IgM Dot-ELISA, with r=0.552 (p=0.0127). These data show that Dot-ELISA can be used for the detection of specific antibodies against S. mansoni in sera from suspected patients or in epidemiological studies and, with further purification of egg antigen and larger samples, IgM Dot-ELISA could be a possible tool for rough estimates of parasite burden in epidemiological studies.

Immunoperoxidase for the detection for the detection of antibodies in cerebrospinal fluid in neurocysticercosis: use of Cysticercus cellulosae and Cysticercus longicollis particles fixed on microscopy slides

The ORF strain of Cysticercus longicollis represents an important model for the study of heterologous antigens in the immunodiagnosis of neurocysticercosis (NC). The immunoperoxidase (IP) technique was standardized using a particulate antigen suspension of Cysticercus longicollis (Cl) and Cysticercus cellulosae (Cc). Cerebrospinal fluid (CSF) samples were incubated on the antigen fixed to microscopy slides; the conjugate employed was anti-IgG-peroxidase and the enzymatic reaction was started by covering the slides with chromogen solution (diaminobenzidine/H2O2). After washing with distilled water, the slide was stained with 2% malachite green in water. Of the CSF samples from 21 patients with NC, 19 (90.5%) were positive, whereas the 8 CSF samples from the control group (100%) were negative. The results of the IP-Cl test applied to 127 CSF samples from patients with suspected NC showed 28.3% reactivity as opposed to 29.1 % for the IP-Cc test. The agreement index for the IP test (Cl x Cc) was 94.2%, with no significant difference between the two antigens.

Amastigotes forms of Trypanosoma cruzi detected in a renal allograft

Trypanosoma cruzi, the causative agent of Chagas’disease assumes two distinct forms in vertebrate hosts: circulating trypomastigote and tissular amastigote. This latter form infects predominantly the myocardium, smooth and skeletal muscle, and central nervous system. The present work describes for the first time the detection of amastigote forms of T. cruzi in the renal parenchyma of a kidney graft recipient one month after transplantation. The patient was serologically negative for Chagas’disease and received no blood transfusion prior to transplant. The cadaver donor was from an endemic area for Chagas’disease. The recipient developed the acute form of the disease with detection of amastigote forms of T. cruzi in the renal allograft biopsy and circulating trypomastigote forms. The present report demonstrates that T. cruzi can infect the renal parenchyma. This mode of transmission warrants in endemic areas of Chagas’disease

Serological follow-up of patients with paracoccidioidomycosis treated with itraconazole using Dot-blot, ELISA and Western-blot

Twenty-seven mycologically proven cases of paracoccidioidomycosis (PCM) were treated with itraconazole (100-200 mg/day in month 1 and 100 mg/day until month 6-8) and evaluated clinically and serologically, up to 3.5 years post-therapy, using Dot-blot and ELISA for measuring the titers of IgG, IgA and IgM anti-P. brasiliensis antibodies and Western-blot for determining IgG, IgA and IgM antibodies against the antigen components of the fungus. Before treatment, 81.5% (Dot-blot) and 84% (ELISA) of the patients presented elevated IgG anti-P. brasiliensis antibody titers which dropped slightly with treatment. On the other hand, the percentages of pre-treatment high-titered sera for IgA and IgM anti-P.brasiliensis were lower (5l.9% and 5l.8%: Dot-blot; 16.5 and 36%: ELISA, respectively) but the titers tended to become negative more frequently with treatment. Prior to treatment, the percentages of positivity for IgG, IgA and IgM anti-P.brasiliensis antibodies in Western-blot were 96%, 20.8% and 41.6%, respectively. Antigens with molecular weights varying from 16-78 kDa, from 21-76 kDa and from 27-78 kDa were reactive for IgG, IgA and IgM antibodies, respectively. The most frequently reactive antigenic components had molecular weights of 27, 33 and 43 kDa for IgG, and 70 for IgA and IgM antibodies. During the period of study, the patients responded well to treatment. The present data confirm the diversity and complexity of the humoral response in PCM, and the importance of utilizing different serological tests to detect IgG, IgA and IgM anti-P. brasiliensis antibodies

Giardia duodenalis: INTER-STRAIN VARIABILITY OF PROTEINS, ANTIGENS, PROTEASES, ISOENZYMES AND NUCLEIC ACIDS

Giardia duodenalis isolates from asymptomatic or symptomatic patients and from animals present similarities and differences in the protein composition, antigenic profile, pattern of proteases and isoenzymes, as well as in nucleic acids analysis. In the present overview, these differences and similarities are reviewed with emphasis in the host-parasite interplay and possible mechanisms of virulence of the protozoon.