Hospital associated methicillin-resist Staphylococcus aureus has long been associated to outbreaks in the hospital environment. In this work, we investigated an outbreak of Hospital associated methicillin-resist Staphylococcus aureus carrying the Panton-Valentine leukocidin gene, which occurred in a large community hospital in Rio de Janeiro, Brazil.

INTRODUÇÃO: Um polimorfismo de nucleotideo único (SNP) no gene codificante para interferon gama influencia a sua produção e pode estar associado à gravidade de diversas doenças infecciosas. O objetivo deste estudo foi avaliar a associação entre SNP para IFNγ+874T/A com a duração da doença, a morbidade e o desenvolvimento de retinocoroidite na toxoplasmose aguda. MÉTODOS: Estudo de caso-controle incluindo 30 pacientes e 90 controles. RESULTADOS: Apesar da ausência de associação estatística, o alelo A foi mais comum entre os casos com retinocoroidite e doença prolongada e o alelo T nas formas mais severas. CONCLUSÕES: Os dados encontrados sugerem uma relação entre o polimorfismo de base única em IFNγ+874T/A com a morbidade e com o desenvolvimento de retinocoroidite por toxoplasmose.

INTRODUCTION: A single nucleotide polymorphism (SNP) in the gene encoding gamma interferon influences its production and is associated with severity of infectious diseases. This study aimed to evaluate the association of IFNγ+874T/A SNP with duration of disease, morbidity, and development of retinochoroiditis in acute toxoplasmosis. METHODS: A case-control study was conducted among 30 patients and 90 controls. RESULTS: Although statistical associations were not confirmed, A-allele was more common among retinochoroiditis cases and prolonged illness, while T-allele was more frequent in severe disease. CONCLUSIONS: Despite few cases, the results could indicate a relation between IFNγ+874T/A single nucleotide polymorphism and clinical manifestations of toxoplasmosis.

The identification of the genotypes of Echinococcus granulosus present in livestock and wild animals within regions endemic for cystic echinococcosis (CE) is epidemiologically important. Individual strains display different biological characteristics that contribute to outbreaks of CE and that must be taken into account in the design of intervention programs. In this study, samples of hydatid cysts due to E. granulosus were collected from alpacas (4) in Puno and pigs (8) in Ayacucho in Peru, an endemic region for CE. Polymerase chain reaction amplification and DNA sequencing of specific regions of the mitochondrial cytochrome C oxidase subunit 1 and NADH dehydrogenase subunit 1 genes confirmed the presence of a strain common to sheep, the G1 genotype, in alpacas. Two different strains of E. granulosus were identified in pigs: the G1 and the G7 genotypes. This is the first report of the G1 genotype of E. granulosus in alpacas in endemic regions of CE in Peru.

Echinococcus granulosus, the etiologic agent of cystic echinococcosis (CE) in humans and other animal species, is distributed worldwide. Ten intra-specific variants, or genotypes (G1-G10), have been defined based on genetic diversity. To determine the genotypes present in endemic areas of Peru, samples were collected from cattle (44), sheep (41) and humans (14) from Junín, Puno Huancavelica, Cusco, Arequipa and Ayacucho. DNA was extracted from protoscolex and/or germinal layers derived from 99 E. granulosus isolates and used as templates to amplify the mitochondrial cytochrome C oxidase subunit 1 gene. The resulting polymerase chain reaction products were sequenced and further examined by sequence analysis. All isolates, independent of the host, exhibited the G1 genotype. Phylogenetic analysis showed that three isolates from Ayacucho shared the same cluster with microvariant G1(4). The G1 genotype is considered the most widespread and infectious form of E. granulosusworldwide and our results confirm that the same patterns apply to this country. Therefore, these findings should be taken into consideration in developing prevention strategies and control programs for CE in Peru.

The seroprevalence of toxoplasmosis in 832 pregnant women in Miracema, Rio de Janeiro, was determined and 75.1% (625) and 2.0% (17) were anti-Toxoplasma gondii IgG and IgM positive, respectively. Out of the 17 IgM positive pregnant women, only one had low avidity IgG corresponding to the acute phase of the infection. All the other women presented with high avidity IgG and also presented with residual IgM anti-T. gondii. Of this sample, 106 received home visits (this includes 11 family nuclei of pregnant women with residual IgM anti-T. gondii, 68 nuclei of only IgG positive pregnant women and 27 nuclei of pregnant women with no antibodies to anti-T. gondii), resulting in 267 individuals visited. Out of these 267 individuals, 21 were positive for IgG and IgM anti-T. gondii and were candidates for the IgG avidity test. All of them presented with high avidity IgG and residual IgM. Five of these IgM+ individuals were (5/238; 2.1%) relatives of IgM negative pregnant women. The other 16 (16/29; 55.2%) were relatives of IgM+ pregnant women who were positive for residual IgM anti-T. gondii. This association was statistically significant (p = 0.0000). The analysis presented herein raises questions regarding the presence of residual IgM anti-T. gondii such as genetic determinants or even constant antigenic stimuli for the same family cluster.

The objective of the present study was to evaluate the specificity of the Montenegro skin test (MST) in an area in Brazil, state of Grande do Sul State (RS), which was considered to be non-endemic for leishmaniasis. Sixty subjects presented a positive MST and were reevaluated by clinical examination, serology and polymerase chain reaction (PCR) of peripheral blood for the detection of subclinical Leishmania infection. None of the subjects presented clinical signs or symptoms of current leishmaniasis or a history of the disease.Leishmania (Viannia) DNA was detected in blood by PCR and hybridization in one subject. The PCR skin test-positive individual remained asymptomatic throughout the study. Clinical examination showed no scars suggestive of past cutaneous leishmaniasis. Human subclinical infection with Leishmania (Viannia) in RS was confirmed by PCR. This is the first report of subclinical infection with this parasite in the human population of this area.

Um estudo seccional parasitológico, clínico, sorológico e molecular, realizado em uma área altamente endêmica para malária, no Rio Negro, Estado do Amazonas, revela alta prevalência de infecção assintomática por Plasmodium vivax. Um total de 109 pessoas de 25 famílias residentes em cinco comunidades do Rio Padauiri, afluente do Rio Negro, foram estudadas. Noventa por cento dos habitantes (90,8%) tinham tido pelo menos um episodio prévio de malária. A sorologia mostrou 85,7% e 46,9% de positividade quando antígenos de P. falciparum e P. vivax MSP-1, foram respectivamente usados. Vinte amostras de sangue submetidas ao PCR foram positivas para P. vivax (20,4%), entretanto, nenhuma foi positiva para o P. falciparum por esta técnica. Nenhum paciente com PCR positivo durante o inquérito e seis meses antes ou depois teve manifestações clínicas de malária, portanto, podemos afirmar que eram assintomáticos. Somente uma criança de 12 anos de idade teve gota espessa positiva para P. vivax. Esta é a primeira descrição de infecção assintomática por Plasmodium na área estudada.

A parasitological, clinical, serological and molecular cross-sectional study carried out in a highly endemic malaria area of Rio Negro in the Amazon State, Brazil, revealed a high prevalence of asymptomatic Plasmodium vivax infection. A total of 109 persons from 25 families were studied in five villages. Ninety-nine inhabitants (90.8%) had at least one previous episode of malaria. Serology showed 85.7% and 46.9% of positivity when P. falciparum antigens and P. vivax MSP-1, respectively, were used. Twenty blood samples were PCR positive for P. vivax (20.4%) and no P. falciparum infection was evidenced by this technique. No individual presenting positive PCR reaction had clinical malaria during the survey neither in the six months before nor after, confirming that they were cases of asymptomatic infection. Only one 12 year old girl presented a positive thick blood smear for P. vivax. This is the first description of asymptomatic Plasmodium infection in this area studied.

Detection of Onchocerca volvulus in Simulium populations is of primary importance in the assessment of the effectiveness of onchocerciasis control programs. In Brazil, the main focus of onchocerciasis is in the Amazon region, in a Yanomami reserve. The main onchocerciasis control strategy in Brazil is the semi-annually mass distribution of the microfilaricide ivermectin. In accordance with the control strategy for the disease, polymerase chain reaction (PCR) was applied in pools of simuliids from the area to detect the helminth infection in the vectors, as recommended by the Onchocerciasis Elimination Program for the Americas and the World Health Organization. Systematic sampling was performed monthly from September 1998 to October 1999, and a total of 4942 blackflies were collected from two sites (2576 from Balawaú and 2366 from Toototobi). The molecular methodology was found to be highly sensitive and specific for the detection of infected and/or infective blackflies in pools of 50 blackflies. The results from the material collected under field conditions showed that after the sixth cycle of distribution of ivermectin, the prevalence of infected blackflies with O. volvulus had decreased from 8.6 to 0.3% in Balawaú and from 4 to 0.1% in Toototobi.

A toxoplasmose infecta milhões de pessoas no mundo inteiro, sendo que a prevalência da infecção humana na maioria dos países está entre 40% e 50%. No Brasil essa taxa aumenta até 80%, dependendo da área estudada. Na maioria dos hospedeiros a infecção é assintomática. A mulher grávida com sorologia negativa pode contribuir para o incremento da morbidade, transmitindo o Toxoplasma gondii para o feto, através da placenta, se adquirir toxoplasmose aguda durante a gravidez. O diagnóstico da toxoplasmose aguda é baseado na detecção de IgM anti-Toxoplasma gondii circulante. A alta sensibilidade das técnicas sorológicas atuais trouxe a realidade da presença de IgM residuais confundindo muitas vezes o diagnóstico final. Nesse sentido, as técnicas moleculares, tais como a reação em cadeia da polimerase (PCR), podem ajudar a uma melhor interpretação do estado real da interação parasito/homem, embora sejam ainda pouco validadas para uso na rotina de diagnóstico laboratorial da toxoplasmose.

Toxoplasmosis infects millions of people worldwide. The prevalence of human infection in many countries is estimated in approximately 40% to 50%. In Brazil this rate increases up to 80%, depending on the studied area. The majority of human hosts present the infection as asymptomatic carriers. Serologically negative pregnant women may contribute to a higher morbidity of the disease due to parasite transmission to the fetus via placenta if acute toxoplasmosis is acquired during pregnancy. The diagnosis of acute toxoplasmosis has relied on the evidence of circulating anti-parasite IgM. The high sensitivity of the present serological techniques has brought results of residual IgM eventually confounding final diagnosis. In this scenario, the molecular techniques, such as the polymerase chain reaction (PCR), may promote a better interpretation of the real status of human/parasite interaction, although they have not been extremely validated for routine use in the diagnosis of toxoplasmosis.

Morpho-biological diversity of Trypanosoma cruzi has been known since Chagas' first works in 1909. Several further studies confirmed the morphological differences among the parasite strains, which were isolated from different reservoirs and vectors, as well as from human beings. In the early sixties, antigenic differences were found in the parasite strains from various sources. These differences, coupled to the observation of regional variations of the disease, led to the proposal of the term cruzi complex to designate the taxon T. cruzi. Since then this protozoan has been typed in distinct biodemes, zymodemes and lineages which were consensually grouped into T. cruzi I, T. cruzi II and into non-grouped strains. T. cruzi genotypic characterization, initially carried out by schizodeme analysis and more recently by various other techniques, has shown a great diversity of the parasite strains. In fact, T. cruzi is formed by groups of heterogeneous sub-population, which present specific characteristics, including distinct histotropism. The interaction of the different infecting clones of the cruzi complex and the human host will determine the morbidity of the disease.

Um total de 117 cartões de rastreamento neonatal foi selecionado anonimamente para a avaliação de fibrose cística (FC) pela análise da mutação deltaF508 usando-se a técnica da reação em cadeia da polimerase (PCR), seguida de eletroforese em gel de poliacrilamida (Page) e pela quantificação da imunotripsina reativa (IRT, Delfia). Uma concentração de IRT menor que 140ng/ml foi encontrada em 116 recém-nascidos. Entre estes foi detectado um heterozigoto deltaF508 com uma concentração de IRT de 4,44ng/ml. Um dos 117 recém-nascidos era homozigoto não-deltaF508 e apresentava uma IRT anormal de 410,7ng/ml. A média da concentração da IRT diferia significativamente conforme este recém-nascido com IRT alterada era incluído ou excluído da amostragem populacional (n = 117, média = 8,207 ± 38,101; n = 116, média = 4,737 ± 6,597, respectivamente). Outra amostra de oito recém-nascidos, previamente rastreados pelo teste de IRT e com níveis elevados do analito, foi testada para a mutação deltaF508. Em cinco deles a mutação deltaF508 foi encontrada em um ou em ambos os cromossomos, correspondendo a 62,25% dos recém-nascidos. De acordo com os resultados obtidos com triagem neonatal pela análise combinada IRT/DNA, pode-se concluir que o método só será eficiente se: a) forem excluídos os fatores que determinam os falso-positivos ou falso-negativos; e b) a detecção de outras mutações forem incluídas na análise dos resultados duvidosos.

A total of 117 newborn screening cards were anonymously selected for cystic fibrosis (CF) screening, searching for the deltaF508 mutation using polymerase chain reaction (PCR) followed by polyacrylamide gel electrophoresis (Page) and by quantification of Immunoreactive trypsin (IRT, Delfia). In 116 newborns an IRT concentration lower than 140ng/ml was evidenced. One of these was a deltaF508 heterozygote with an IRT concentration of 4,44ng/ml. One newborn was a non-deltaF508 homozygote with an IRT concentration of 410,7ng/ml. The IRT concentration average was significantly different if the newborn with the abnormal IRT was included or excluded from the population sample (n = 117, means = 8.207 ± 38.101; n = 116, means = 4.737 ± 6.597, respectively). Another sample of 8 newborns previously screened by IRT test and with elevated IRT levels was analyzed for deltaF508 mutation. The deltaF508 mutation was found in one or both chromosomes in five newborns, corresponding to 62.25% of the sample. Results obtained with two-tier IRT/DNA analysis showed that the approach only will be effective if: a) factors leading to false positives and false negatives are excluded; and b) molecular analysis of other mutations are included among those children with undefined results.

American trypanosomiasis is a common zoonosis in Colombia and Trypanosoma cruzi presents a wide distribution throughout the country. Although some studies based on enzyme electrophoresis profiles have described the population structure of the parasite, very few molecular analyses of genotipic markers have been conducted using Colombian strains. In this study, we amplified the non-transcribed spacer of the mini-gene by PCR, typing the isolates as T. cruzi I, T. cruzi zymodeme 3 or T. rangeli. In addition, the internal transcribed spacers of the ribosomal gene concomitant with the 5.8S rDNA were amplified and submitted to restriction fragment polymorphism analysis. The profiles were analyzed by a numerical methodology generating a phenetic dendrogram that shows heterogeneity among the T. cruzi isolates. This finding suggests a relationship between the complexity of the sylvatic transmission cycle in Colombia and the diversity of the sylvan parasites.

Com o objetivo de estudar o comportamento biológico de cepas do T. cruzi e determinar a possível relação entre o biodema da cepa e as formas clínicas da doença de Chagas, 14 cepas do protozoário isoladas de humanos, procedentes de Pains, Iguatama e Berilo, foram avaliadas. Para estudar o comportamento biológico das cepas, grupos de camundongos albinos suíços, machos, pesando entre 10-15 gramas foram infectados com 1x10(4) tripomastigotas sangüíneos para avaliação da infectividade, parasitemia, morfologia dos tripomastigotas sangüíneos, virulência e distribuição do protozoário nos tecidos. Nove cepas apresentaram comportamento similar ao da cepa São Felipe do biodema II e cinco se caracterizaram como pertencentes ao biodema III. Não foi possível estabelecer uma relação entre o biodema da cepa e gravidade da doença nos pacientes.

In order to study the biological behavior of T. cruzi strains and to determine a putative association between their biodeme and the clinical forms of Chagas disease, 14 strains isolated from humans were evaluated. The individuals were from the municipalities of Pains, Iguatama and Berilo (Minas Gerais State). The biological behavior was evaluated in albino swiss mice, weighing 10 to 15 grams, which were infected with 1x10(4) blood tripomastigotes. The infectivity, parasitemia, tripomastigote morphology, virulence and the tissue distribution of the protozoan were analyzed. A behavior similar to biodeme II (São Felipe strain) was observed in 9 strains, while 5 stocks were characterized as belonging to biodeme III. It was not possible to establish a relationship between the biodeme strain and the severity of the disease in the patients.