Hospital-associated methicillin-resistant Staphylococcus aureus carrying the PVL gene outbreak in a Public Hospital in Rio de Janeiro, Brazil

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.

Genetic polymorphism for IFNγ +874T/A in patients with acute toxoplasmosis / Polimorfismo genético para IFNγ +874T/A em pacientes com toxoplasmose aguda

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.

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.

Echinococcus granulosus genotypes circulating in alpacas (Lama pacos) and pigs (Sus scrofa) from an endemic region in Peru

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.

Giardiasis as zoonosis: between proof of principle and paradigm in the Northwestern region of São Paulo State, Brazil

OBJECTIVE: In order to evaluate the potential zoonotic transmission of Giardia duodenalis, isolates from humans and dogs in the Northwestern region of the São Paulo State, Brazil were characterized based on the β-giardin gene. METHODS: The samples were analyzed by sequencing of the Nested-PCR products. RESULTS: The A1 and A2 subgenotypes were detected in human and dogs. Cysts of assemblage B, C and D have not been found in any isolates studied. CONCLUSIONS: These results are consistent with the view that giardiasis in the largest endemic region of the Brazil should not be seen as a single entity.

Molecular characterization of Echinococcus granulosusfrom Peru by sequencing of the mitochondrial cytochrome C oxidase subunit 1 gene

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.

Da violeta de genciana à sorologia: o controle da transmissão da doença de chagas nos bancos de sangue / Gentian violet to serology: the control of transmission of Chagas disease in blood banks

Revisões históricas aos avanços científicos para o controle da doença, o Simpósio Internacional Comemorativo do Centenário da Descoberta da Doença de Chagas (1909-2009).

Association of the presence of residual anti-Toxoplasma gondii IgM in pregnant women and their respective family groups in Miracema, Northwest Rio de Janeiro, Brazil

The seroprevalence of toxoplasmosis in 832 pregnant women in Miracema, Rio de Janeiro, was determined and 75.1 percent (625) and 2.0 percent (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 percent) relatives of IgM negative pregnant women. The other 16 (16/29; 55.2 percent) 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.

First encounter of subclinical human Leishmania (Viannia) infection in State of Rio Grande do Sul, Brazil

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.

Cross sectional study reveals a high percentage of asymptomatic Plasmodium vivax infection in the Amazon Rio Negro area, Brazil

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 percent) had at least one previous episode of malaria. Serology showed 85.7 percent and 46.9 percent 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 percent) 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.

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 por cento) tinham tido pelo menos um episodio prévio de malária. A sorologia mostrou 85,7 por cento e 46,9 por cento 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 por cento), 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.

Detection of Onchocerca volvulus (Nematoda: Onchocercidae) infection in vectors from Amazonian Brazil following mass Mectizan™ distribution

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 percent in Balawaú and from 4 to 0.1 percent in Toototobi.

The use of radionuclide DNA probe technology for epidemiological studies of tegumentary leishmaniasis in Mato Grosso state

DNA hybridisation, using probes labelled with 32P, was used to type Leishmania samples isolated from patients living in endemic areas of Mato Grosso State (Brazil), and clinically diagnosed as having tegumentary leishmaniasis. kDNA cloned mini-circle probes specific for the Leishmania mexicana and Leishmania braziliensis complexes were used. The results showed that L. braziliensis is the predominant group infecting human patients in the state. Sixty-eight samples were typed, 64 samples (94.1 percent) belonging to the L. braziliensis complex and only four (5.9 percent) belonging to the L. mexicana complex. Accurate identification of the Leishmania permits better orientation of the medical follow-up, since clinical manifestations may vary depending on the complex to which the parasite belongs. The epidemiological information furnished by the identification of the Leishmania in given endemic area is also essential for the design of appropriate control measures

Hibridização, utilizando sondas de DNA marcadas com 32P, foi utilizada para a tipagem de amostras de Leishmania isoladas de pacientes do estado do Mato Grosso (Brasil), diagnosticados clinicamente como portadores de leishmaniose tegumentar. Sondas de minicírculos clonados de kDNA, específicas para os complexos Leishmania mexicana e Leishmania braziliensis, foram utilizadas. Os resultados demonstraram que o complexo L. brasiliensis é o grupo predominante infectando pacientes humanos no estado do Mato Grosso. Foram tipadas 68 amostras: 64 (94,1 por cento) foram identificadas como pertencentes ao complexo L. brasiliensis e somente 4 (5,9 por cento) como pertencentes ao complexo L. mexicana. A tipagem de Leishmania é importante para um melhor acompanhamento médico, uma vez que as manifestações clínicas podem variar em função do complexo ao qual o parasita pertence. A informação fornecida pela identificação também é essencial para a definição das medidas de controle mais adequadas e compreensão da epidemiologia da doença.

Diagnóstico molecular da toxoplasmose: revisão / Molecular diagnosis of toxoplasmosis: review

A toxoplasmose infecta milhões de pessoas no mundo inteiro, sendo que a prevalência da infeccão humana na maioria dos países está entre 40 por cento e 50 por cento. No Brasil essa taxa aumenta até 80 por cento, dependendo da área estudada. Na maioria dos hospedeiros a infeccão 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 deteccão de IgM anti-Toxoplasma gondii circulante. A alta sensibilidade das técnicas sorológicas atuais trouxe a realidade da presenca de IgM residuais confundindo muitas vezes o diagnóstico final. Nesse sentido, as técnicas moleculares, tais como a reacão em cadeia da polimerase (PCR), podem ajudar a uma melhor interpretacão do estado real da interacão parasito/homem, embora sejam ainda pouco validadas para uso na rotina de diagnóstico laboratorial da toxoplasmose.

Rastreamento da fibrose cística usando-se a análise combinada do teste de IRT neonatal e o estudo molecular da mutaçäo deltaF508 / Cystic fibrosis screening by two-tiered newborn IRT assay and deltaF508 mutation molecular analysis

Um total de 117 cartöes de rastreamento neonatal foi selecionado anonimamente para a avaliaçäo de fibrose cística (FC) pela análise da mutaçäo deltaF508 usando-se a técnica da reaçäo em cadeia da polimerase (PCR), seguida de eletroforese em gel de poliacrilamida (Page) e pela quantificaçäo da imunotripsina reativa (IRT, Delfia). Uma concentraçäo de IRT menor que 140ng/ml foi encontrada em 116 recém-nascidos. Entre estes foi detectado um heterozigoto deltaF508 com uma concentraçäo de IRT de 4,44ng/ml. Um dos 117 recém-nascidos era homozigoto näo-deltaF508 e apresentava uma IRT anormal de 410,7ng/ml. A média da concentraçäo 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 mutaçäo deltaF508. Em cinco deles a mutaçäo deltaF508 foi encontrada em um ou em ambos os cromossomos, correspondendo a 62,25 por cento 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 detecçäo de outras mutações forem incluídas na análise dos resultados duvidosos

Should Trypanosoma cruzi be called "cruzi" complex? A review of the parasite diversity and the potential of selecting population after in Vitro culturing and mice infection

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

Genetic diversity of Colombian sylvatic Trypanosoma cruzi isolates revealed by the ribosomal DNA

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

Biodemas de cepas do Trypanosoma cruzi isoladas de humanos de três áreas endêmicas de Minas Gerais / Biodemes of Trypanosoma cruzi strains isolated from humans from three endemic areas in Minas Gerais State

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 (SÒo 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.

Identification of Leishmania chagasi from skin in Leishmania/HIV co-infection: a case report

A case of HIV/Leishmania co-infection presenting both visceral and cutaneous manifestations is reported. Leishmania infection was confirmed by conventional methods (parasitological approach and serology) and by PCR. Leishmania chagasi isolated from the skin lesion was characterized by enzyme electrophoresis and by restriction fragment length polymorphism of the internal transcribed spacer of the ribosomal gene.

Frequency of Infection of Lutzomyia Phlebotomines with Leishmania braziliensis in a Brazilian endemic area as assessed by pinpoint capture and polymerase chain reaction

Leishmania infected of Lutzomyia spp. are rare in endemic areas. We tested the hypothesis that there is clustering of infected vectors by combining pinpoint capture with sensitive L. braziliensis kDNA minicircle specific PCR/dot blot in an endemic area in the State of Bahia. Thirty out of 335 samples (10 to 20 sand flies/sample; total of 4,027 female sand flies) were positive by PCR analysis and dot blot leading to a underestimated overall rate of 0.4 percent positive phlebotomines. However, 83.3 percent of the positive samples were contributed by a single sector out of four sectors of the whole studied area. This resulted in a rate of 1.5 percent Leishmania positive phlebotomines for this sector, far above rates of other sectors. Incidence of American cutaneous leishmaniasis cases for this sector was about twice that for other sectors. Our results show that there is a non-homogeneous distribution of Leishmania-infected vectors. Such a clustering may have implications in control strategies against leishmaniasis, and reinforces the necessity of understanding the ecological and geographical factors involved in leishmanial transmission

Chagas disease in the Brazilian Amazon: IV. a new cross-sectional study

A new conglomerate family sample of 194 dwellings with 996 resident persons were studied in the town of Barcelos, State of Amazonas, in order to re-evaluate the risk of Chagas disease. During the survey the persons were interviewed and in this occasion we showed to them a collection of Panstrongylus, Rhodnius and Triatoma, asking if they recognized and eventually have been bitten by this kind of bugs. At this time we collected 500 ul of blood in microtainer® tubes from 886 interviewed persons who gave permission after informed consent. A screening test for T. cruzi antibodies based on agglutination of colored polymer particles, sensitized with three different synthetic peptides of T. cruzi (ID-PaGIA Chagas Test)®, showed 13.2 percent of sera positivity, but only 6.8 percent were confirmed by indirect immunofluorescence, and ELISA with purified T. cruzi antigens. Two hundred and six interviewed persons (20.7 percent) recognized the triatomines, as "piaçavas' lice" and 62 (30 percent) confirmed that have been bitten by the bugs, 25.8 percent of them had a positive serology for T. cruzi infection. Electrocardiographic alterations were shown in 9.3 percent of the seropositives and in 11.9 percent of the seronegative cases. This was considered not statistically significant

Parasite persistence in treated chagasic patients revealed by xenodiagnosis and polymerase chain reaction

Polymerase chain reaction (PCR) was compared with xenodiagnosis performed 20 years after trypanocidal chemotherapy to investigate parasite clearance. Eighty-five seropositive individuals for Chagas disease presenting a positive xenodiagnosis were treated with specific drugs; 37 in the acute phase and 48 in the chronic phase. Fifteen chronic assymptomatic patients received a placebo. Treatment in the acute phase led to PCR negative results in 73 percent of the cases, while xenodiagnosis was negative in 86 percent. In the chronic phase, PCR was negative in 65 percent of the patients and 83 percent led to xenodiagnosis negative results. Regarding the untreated group (placebo), 73 percent gave negative results by xenodiagnosis, of which 36 percent were positive by PCR. Individuals that were considered seronegative (n=10), presented unequivocally negative results in the PCR demonstrating the elimination of parasite DNA. Seventeen individuals had their antibodies titers decreased to such a level that the final results were considered as doubtful and 16 of them presented negative PCR. The molecular method represents a clear advantage over conventional techniques to demonstrate persistent infections in Chagas disease patients that underwent chemotherapy