Performance of IS6110-LAMP assay for detection of Mycobacterium tuberculosis complex in blood and urine samples from patients with extrapulmonary tuberculosis.

BACKGROUND: The diagnosis of extrapulmonary tuberculosis (EPTB) shows numerous difficulties because of non-specific symptomatology and low sensitivity of conventional methods. Loop-mediated isothermal amplification (LAMP) is a fast and low-cost technique, which can amplify under isothermal conditions an amount of target DNA copies into approximately a billion copies. OBJECTIVE: The present study aimed to evaluate a IS6110-LAMP system for Mycobacterium tuberculosis detection in blood and urine samples from patients with EPTB. METHODS: The collected samples (n = 122) were stratified in two groups: Group EPTB - patient samples with confirmed EPTB (n = 61); Group non-TB - patient samples without TB (n = 61). The urine samples underwent decontamination, and the components of blood samples were separated (plasma and PBMC). DNA extractions were performed in all biological samples followed by IS6110-LAMP assay technique. The detection limit was evaluated through dilution curves (1:10) using Mtb reference strain (H37Rv) genomic DNA. FINDINGS: The detection limit of IS6110-LAMP was 10 fg/µL (∼10-20 bacilli/µL). The IS6110-LAMP technique sensitivity and specificity were 95.65 % and 79.25 %, respectively, with a general kappa agreement index of 0.762. MAIN CONCLUSIONS: Based on these results, IS6110-LAMP test showed considerable diagnostic parameters, being able to aid in the speed and accuracy of the final EPTB diagnosis.

Tuberculose: conhecimento e adesão às medidas profiláticas em indivíduos contatos da cidade do Recife, Pernambuco, Brasil / Tuberculosis: knowledge and adherence to prophylactic measures in contact individuals of the city of Recife, Pernambuco, Brazil

Resumo Introdução Para o controle da tuberculose, é fundamental interromper a cadeia de transmissão da doença. O Ministério da Saúde preconiza que 100% dos contatos sejam examinados e iniciem tratamento da Infecção Latente por Mycobacterium tuberculosis. Nesse sentido, o conhecimento sobre a doença e a adesão à profilaxia por parte desses contatos são fatores que podem interferir no adequado controle da tuberculose. Objetivo Descrever o conhecimento dos contatos de portadores de tuberculose sobre a doença e sua adesão às medidas profiláticas no Distrito Sanitário II em Recife/PE. Método Estudo quantitativo, descritivo, utilizando questionários padronizados, aplicados a 140 contatos de tuberculose notificados de janeiro a dezembro de 2015. Análise dos dados realizada por meio de frequências simples. Resultados Dentre os entrevistados, 75,7% eram do sexo feminino, 55% pardos, com baixos níveis de escolaridade e renda familiar. Destes, 84,3% acreditam que a tuberculose é grave, 48,6% consideram que a transmissão se faz compartilhando utensílios. Apenas 55% foram convidados para serem examinados e 76% referiram não saber que deveriam ir à consulta ou a importância desta. Conclusão Os contatos de tuberculose possuem precário conhecimento sobre a doença, baixa adesão à atenção primária à saúde e a busca ativa dos contatos ainda é ineficiente.

Abstract Background For the control of tuberculosis, it is essential to interrupt its chain of transmission. The Ministry of Health recommends 100% of contacts being examined and initiated treatment of the Latent Mycobacterium tuberculosis infection. In this sense, the knowledge about the disease and adherence to prophylaxis by these contacts are factors that can interfere in the adequate control of tuberculosis. Objective To describe the knowledge of the contacts of tuberculosis patients on the disease and their adherence to prophylactic measures in the Sanitary District II in Recife / PE. Method A quantitative and descriptive study was carried out using standardized questionnaires, applied to 140 contacts of tuberculosis notified from January to December 2015. Data analysis carried out through simple frequencies. Results Among the interviewees, 75.7% were female, 55% brown, with low levels of schooling and family income; of these 84.3% believe that tuberculosis is serious, 48.6% consider that transmission is done by sharing utensils. Only 55% were invited to be examined and 76% reported not knowing they should go to the consultation or the importance of these. Conclusion The contacts of tuberculosis have poor knowledge about the disease, low adherence to primary health care and the active search for contacts is still inefficient.

Performance of the IS6110-TaqMan® assay in the diagnosis of extrapulmonary tuberculosis from different biological samples.

INTRODUCTION: This study evaluated the performance of the IS6110-TaqMan® assay in different types of biological samples and tissues for laboratory diagnosis of extrapulmonary tuberculosis. METHODS: 143 biological samples and tissues from patients with suspected extrapulmonary tuberculosis from the health services of Recife/Pernambuco/Brazil were evaluated with the IS6110-TaqMan® assay. RESULTS: The sensitivities of the IS6110-TaqMan® assay calculated for blood, urine, both blood and urine samples, tissue biopsies, extrapulmonary body fluid samples, and all samples from patients calculated together were 55.9%, 33.3%, 68.8%, 43.8%, 29.6%, and 73.7%, respectively, and the specificities were 80%, 100%, 78.6%, 100%, 100%, and 84.2%, respectively. CONCLUSIONS: The accuracy of qPCR was high in various clinical sample types. The analysis of more than one type of clinical sample collected from the same patient with extrapulmonary tuberculosis enhances the diagnostic power of the IS6110-TaqMan® assay when compared with the use of only one clinical sample.

Performance of the IS6110-TaqMan® assay in the diagnosis of extrapulmonary tuberculosis from different biological samples

Abstract INTRODUCTION: This study evaluated the performance of the IS6110-TaqMan® assay in different types of biological samples and tissues for laboratory diagnosis of extrapulmonary tuberculosis. METHODS: 143 biological samples and tissues from patients with suspected extrapulmonary tuberculosis from the health services of Recife/Pernambuco/Brazil were evaluated with the IS6110-TaqMan® assay. RESULTS: The sensitivities of the IS6110-TaqMan® assay calculated for blood, urine, both blood and urine samples, tissue biopsies, extrapulmonary body fluid samples, and all samples from patients calculated together were 55.9%, 33.3%, 68.8%, 43.8%, 29.6%, and 73.7%, respectively, and the specificities were 80%, 100%, 78.6%, 100%, 100%, and 84.2%, respectively. CONCLUSIONS The accuracy of qPCR was high in various clinical sample types. The analysis of more than one type of clinical sample collected from the same patient with extrapulmonary tuberculosis enhances the diagnostic power of the IS6110-TaqMan® assay when compared with the use of only one clinical sample.

Self-assembled monolayers of mercaptobenzoic acid and magnetite nanoparticles as an efficient support for development of tuberculosis genosensor.

In this work, a genosensor for the electrochemical detection of genomic DNA from Mycobacterium tuberculosis was developed. The biosensor is based on self-assembled monolayers of mercaptobenzoic acid (MBA) and magnetite nanoparticles (Fe3O4Nps) on bare gold electrode for immobilization of DNA probe. The aim of this work was the development of a platform based on cysteine-coated magnetic Fe3O4Nps linked via the carboxylate group from MBA to the work electrode surface and subsequently to the DNA probe. The probe-genome interaction was evaluated using a [Fe(CN)6](4-)/[Fe(CN)6](3-) redox pair. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to evaluate the bioelectrochemical behavior of the sensor. Atomic force microscopy images showed Fe3O4Nps immobilized across the electrode surface. The interaction of the sensor with different genome DNA concentrations resulted in changes in the charge transfer resistance, indicating a possible use for tuberculosis detection at low concentrations (detection limit of 6ngµL(-1)).

The performance of an in-house nested-PCR technique for pleural tuberculosis diagnoses.

INTRODUCTION: This study evaluated the performance of an in-house nested-PCR system for the detection of the Mycobacterium tuberculosis complex in pleural fluid, blood and urine samples from pleural effusion tuberculosis patients by health services physicians in Pernambuco, Brazil. METHODS: A prospective double-blind study with 37 hospitalized patients of both sexes, aged over 15, was used to investigate the diagnosis of pleural effusion. The criteria used to define the cases included the demonstration of bacillus in biological samples by smear or culture or by a granulomatous finding in the histopathological examination, associated with an evident response to specific treatments to each clinical situation. Pleural fluid, blood and urine samples were collected and subjected to routine tests and the nested PCR technique to assess for M. tuberculosis amplification. RESULTS: In total, 37 pleural effusion patients took part in the study, of whom 19 (51.3%) had tubercular etiologies and 18 (48.7%) had etiologies from other causes. When the pleural fluid, blood and/or urine sample in-house nested-PCR sensitivities were evaluated simultaneously, the results were positive regardless of the biological specimen (the sensitivity was 84.2%); however, when the blood and/or urine samples were analyzed together, the sensitivity was 72.2%. When the pleural fluid samples were evaluated alone, the sensitivity was only 33.3%. CONCLUSIONS: The performance of the diagnostic pleural tuberculosis nested-PCR was directly related to the diversity of the samples collected from the same patient. Additionally, this study may identify a need to prioritize non-invasive blood and urine collection for this diagnosis.

The performance of an in-house nested-PCR technique for pleural tuberculosis diagnoses

Introduction This study evaluated the performance of an in-house nested-PCR system for the detection of the Mycobacterium tuberculosis complex in pleural fluid, blood and urine samples from pleural effusion tuberculosis patients by health services physicians in Pernambuco, Brazil. Methods A prospective double-blind study with 37 hospitalized patients of both sexes, aged over 15, was used to investigate the diagnosis of pleural effusion. The criteria used to define the cases included the demonstration of bacillus in biological samples by smear or culture or by a granulomatous finding in the histopathological examination, associated with an evident response to specific treatments to each clinical situation. Pleural fluid, blood and urine samples were collected and subjected to routine tests and the nested PCR technique to assess for M. tuberculosis amplification. Results In total, 37 pleural effusion patients took part in the study, of whom 19 (51.3%) had tubercular etiologies and 18 (48.7%) had etiologies from other causes. When the pleural fluid, blood and/or urine sample in-house nested-PCR sensitivities were evaluated simultaneously, the results were positive regardless of the biological specimen (the sensitivity was 84.2%); however, when the blood and/or urine samples were analyzed together, the sensitivity was 72.2%. When the pleural fluid samples were evaluated alone, the sensitivity was only 33.3%. Conclusions The performance of the diagnostic pleural tuberculosis nested-PCR was directly related to the diversity of the samples collected from the same patient. Additionally, this study may identify a need to prioritize non-invasive blood and urine collection for this diagnosis. .

Bone tuberculosis: a case report on child.

The authors report a case of a 12-year-old child with a complaint of pain and deformity in the lower thoracic region that had lasted for two years. Clinical, epidemiological and laboratory characteristics associated with images of apparent damage in the T9-T10 and T11-T12 vertebrae taken by radiography of the thoracic spine and nuclear magnetic resonance in addition to the positivity of the molecular test based on the polymerase chain reaction, led to tuberculous spondylitis being diagnosed and specific therapy was started. Culture of vertebral biopsy was positive for Mycobacterium tuberculosis after thirty days.

Bone tuberculosis: a case report on child

The authors report a case of a 12-year-old child with a complaint of pain and deformity in the lower thoracic region that had lasted for two years. Clinical, epidemiological and laboratory characteristics associated with images of apparent damage in the T9-T10 and T11-T12 vertebrae taken by radiography of the thoracic spine and nuclear magnetic resonance in addition to the positivity of the molecular test based on the polymerase chain reaction, led to tuberculous spondylitis being diagnosed and specific therapy was started. Culture of vertebral biopsy was positive for Mycobacterium tuberculosis after thirty days.

Avaliação do RNA mensageiro (RNAm) do Mycobacterium tuberculosis como marcador de cura em pacientes com tuberculose pulmonar / Assessment of messenger RNA (mRNA) of Mycobacterium tuberculosis as a marker of cure in patients with pulmonary tuberculosis

A tuberculose (TB) é um dos grandes problemas de saúde pública mundial devido às suas altas taxas de morbimortalidade e índices de transmissão, apesar de existir tratamento e medidas eficazes de controle da doença. O diagnóstico precoce associado a uma terapêutica adequada é essencial para a eficácia dos programas públicos de controle. As técnicas diagnósticas, baciloscopia e cultura, utilizadas de rotina para a detecção do Mycobacterium tuberculosis em amostras clínicas são falhas em sensibilidade e na demora da obtenção dos resultados, respectivamente. A cultura é considerada o método padrão-ouro para avaliar a viabilidade do bacilo em pacientes com tuberculose em vigência de tratamento específico, porém, por ser laboriosa e necessitar de pelo menos 4 semanas para o crescimento do bacilo, dificulta bastante o monitoramento clínico e a resposta do paciente às drogas tuberculostáticas. Neste contexto, os métodos moleculares vêm sendo desenvolvidos com destaque para a tecnologia da reação em cadeia da polimerase (PCR) destacando a Transcrição Reversa seguida de PCR quantitativa em tempo real (RT-qPCR) utilizando o RNA mensageiro que expressa bem a viabilidade bacilar. Neste trabalho foi analisado o desempenho da RT-qPCR utilizando como alvo o gene 85B do Mycobacterium tuberculosis na detecção e resposta ao tratamento específico da tuberculose pulmonar. Foi realizada uma padronização com diferentes concentrações dos primers e sonda desenhados por Desjardin et al, (1999). Construiu-se uma curva padrão de DNA plasmidial gerando um limite de detecção de 10pg/1x10 e-6 (7x10 e7 cópias/reação), epson = 106, R2= 0,98 por cento, e slope= -3,18. O sistema foi avaliado em 98 pacientes com suspeita de TB pulmonar apresentando uma sensibilidade de 91,07 por cento e especificidade de 97,61 por cento, quando comparado à cultura. Em 56 pacientes com tuberculose pulmonar acompanhados durante 30 dias de tratamento específico verificou-se que a RT-qPCR e a cultura apresentaram uma excelente concordância, tendo sido observado um declínio de bacilos viáveis nos dias 15 e 30 após o início da terapêutica na maioria deles. Desta forma, os resultados encontrados sugerem que a RT-qPCR é uma ferramenta que pode ser utilizada no monitoramento clínico e terapêutico, como sinalizador de resistência bacteriana e indicador do período de transmissibilidade do M. tuberculosis em pacientes com TB pulmonar submetidos a tratamento específico.

Evaluation of a nested-pcr for Mycobacterium tuberculosis detection in blood and urine samples

The polymerase chain reaction (PCR) and its variations, such as the nested-PCR, have been described as promising techniques for rapid diagnosis of tuberculosis (TB). With the aim of evaluating the usefulness of a nested-PCR method on samples of blood and urine of patients suspected of tuberculosis we analyzed 192 clinical samples, using as a molecular target the insertion element IS6110 specific of M. tuberculosis genome. Nested-PCR method showed higher sensitivity in patients with extrapulmonary tuberculosis (47.8 percent and 52 percent in blood and urine) when compared to patients with the pulmonary form of the disease (sensitivity of 29 percent and 26.9 percent in blood and urine), regardless of the type of biological sample used. The nested-PCR is a rapid technique that, even if not showing a good sensitivity, should be considered as a helpful tool especially in the extrapulmonary cases or in cases where confirmatory diagnosis is quite difficult to be achieved by routine methods. The performance of PCR-based techniques should be considered and tested in future works on other types of biological specimens besides sputum, like blood and urine, readily obtainable in most cases. The improving of M. tuberculosis nested-PCR detection in TB affected patients will give the possibility of an earlier detection of bacilli thus interrupting the transmission chain of the disease.

Evaluation of a nested-PCR for mycobacterium tuberculosis detection in blood and urine samples.

The polymerase chain reaction (PCR) and its variations, such as the nested-PCR, have been described as promising techniques for rapid diagnosis of tuberculosis (TB). With the aim of evaluating the usefulness of a nested-PCR method on samples of blood and urine of patients suspected of tuberculosis we analyzed 192 clinical samples, using as a molecular target the insertion element IS6110 specific of M. tuberculosis genome. Nested-PCR method showed higher sensitivity in patients with extrapulmonary tuberculosis (47.8% and 52% in blood and urine) when compared to patients with the pulmonary form of the disease (sensitivity of 29% and 26.9% in blood and urine), regardless of the type of biological sample used. The nested-PCR is a rapid technique that, even if not showing a good sensitivity, should be considered as a helpful tool especially in the extrapulmonary cases or in cases where confirmatory diagnosis is quite difficult to be achieved by routine methods. The performance of PCR-based techniques should be considered and tested in future works on other types of biological specimens besides sputum, like blood and urine, readily obtainable in most cases. The improving of M. tuberculosis nested-PCR detection in TB affected patients will give the possibility of an earlier detection of bacilli thus interrupting the transmission chain of the disease.

Diferenciação de micobactérias por PCR multiplex / Differentiation of micobacteria by multiplex PCR

O trabalho visou à otimização de um método baseado na reação em cadeia da polimerase multiplex - para diferenciação de micobactérias de interesse para a saúde pública. A PCR Multiplex baseou-se na amplificação simultânea do genehsp65, presente em todo gênero Mycobacterium, do gene dnaJ, presente apenas em Mycobacterium tuberculosis e Mycobacterium avium e da sequência de inserção IS6110 presente no complexo Mycobacterium tuberculosis, gerando amplicons de 165pb, 365pb e 541pb, respectivamente. O limite de detecção foi de 1fg para o alvo hsp65, 100pg para o dnaJ e 0,1fg para o IS6110. A PCR multiplex detectou até 100pg de DNA de Mycobacterium tuberculosis. O sistema demonstrou ser específico e sensível na detecção de Mycobacterium tuberculosis, Mycobacterium bovis, Mycobacterium avium e Mycobacterium smegmatis. Os resultados obtidos utilizando cepas de referência demonstraram que a PCR multiplex pode ser uma ferramenta rápida, sensível e específica na diferenciação de micobactérias.

This study aimed to optimize a method based on the polymerase chain reaction - multiplex PCR - for differentiation of mycobacteria species of interest for public health. The multiplex PCR was based on simultaneous amplification of the hsp65 gene, which is present in all species of the Mycobacterium genus, the dnaJ gene, which is present only in Mycobacterium tuberculosis and Mycobacterium avium and the IS6110 insertion sequence, which is present in the Mycobacterium tuberculosis complex, generating amplicons of 165 bp, 365 bp and 541 bp, respectively. The detection limit was 1 fg for the hsp65 target, 100 pg for dnaJ and 0.1 fg for IS6110. The multiplex PCR detected down to 100 pg of DNA of Mycobacterium tuberculosis. The system was shown to be specific and sensitive for detection of Mycobacterium tuberculosis, Mycobacterium bovis, Mycobacterium avium and Mycobacterium smegmatis. The results obtained using reference strains of mycobacteria showed that multiplex PCR may be a fast, sensitive and specific tool for differentiation of mycobacteria.

Performance of nested PCR in the specific detection of Mycobacterium tuberculosis complex in blood samples of pediatric patients.

OBJECTIVE: To evaluate the performance of nested PCR (nPCR) in detecting the Mycobacterium tuberculosis complex in blood samples of patients suspected of having TB, in order to determine its potential for use as an auxiliary tool in the laboratory diagnosis of TB in children. METHODS: Detection of the M. tuberculosis complex in blood samples using as a target the insertion sequence IS6110 of the genomic DNA of the bacillus. Blood samples of 120 patients were evaluated. All of the patients were under 15 years of age at the time of their treatment at public hospitals in the city of Recife, Brazil (between January of 2003 and August of 2005). Attending physicians at the hospitals diagnosed TB based on the criteria recommended by the American Thoracic Society. The nPCR amplified a 123-bp fragment with outer oligonucleotides (IS1/IS2) and, in the subsequent reaction, using inner oligonucleotides (IS3/IS4), generating an 81-bp amplicon. RESULTS: Active or latent TB was found in 65 patients, TB was ruled out in 28 suspected cases, and 27 patients were TB-free (controls). The sensitivity of nPCR was 26.15% and was significantly higher for the extrapulmonary form of the disease (55.56%) than for the pulmonary form (18.18%). The specificity was 92.73%. CONCLUSIONS: Despite the difficulties in diagnosing TB in children and the low number of cases evaluated in the present study, nPCR in blood samples proved to be a rapid and specific technique, albeit one with low sensitivity. In order to establish its true usefulness in the diagnosis of paucibacillary forms, especially extrapulmonary TB, further studies need to be carried out with a larger sample of children and analyzing biological specimens other than blood.

Desempenho da técnica nested PCR na detecção específica do complexo Mycobacterium tuberculosis em amostras sanguíneas de pacientes pediátricos / Performance of nested PCR in the specific detection of Mycobacterium tuberculosis complex in blood samples of pediatric patients

Objetivo: Avaliar o desempenho da técnica nested PCR (nPCR) para detectar o complexo Mycobacterium tuberculosis em amostras de sangue de pacientes com suspeita de TB para sua possível utilização como uma ferramenta auxiliar no diagnóstico laboratorial da doença em crianças. Métodos: Detecção do complexo M. tuberculosis em amostras de sangue usando como alvo a sequência de inserção IS6110 do DNA genômico do bacilo. Foram avaliados 120 pacientes, menores de 15 anos de idade, de ambos os sexos, provenientes de hospitais públicos do Recife (PE), no período entre janeiro de 2003 e agosto de 2005. O diagnóstico de TB foi realizado pelo médico assistente do serviço de saúde de acordo com os critérios da Sociedade Torácica Americana. A nPCR amplificou um fragmento de 123 pb com oligonucleotídeos externos (IS1/IS2) e, na reação subsequente, com oligonucleotídeos internos (IS3/IS4), gerando um amplicon de 81 pb. Resultados: A TB ativa ou latente esteve presente em 65 pacientes, foi descartada em 28 suspeitos e 27 não tinham a doença (controles). A sensibilidade da nPCR foi de 26,15%, sendo significativamente maior na forma extrapulmonar (55,56%) em relação à pulmonar (18,18%), e a especificidade foi de 92,73%. Conclusões: Diante das dificuldades diagnósticas da TB infantil e do baixo número de casos estudados,a nPCR em sangue demonstrou ser uma técnica rápida e específica, mas com baixa sensibilidade. Para saber a suareal utilidade no diagnóstico de formas paucibacilares, sobretudo as extrapulmonares, novas pesquisas devem ser desenvolvidas com uma casuística maior de crianças e com outros espécimes biológicos além do sangue.

Objective: To evaluate the performance of nested PCR (nPCR) in detecting the Mycobacterium tuberculosis complex in blood samples of patients suspected of having TB, in order to determine its potential for use as an auxiliary tool in the laboratory diagnosis of TB in children. Methods: Detection of the M. tuberculosis complex in blood samples using as a target the insertion sequence IS6110 of the genomic DNA of the bacillus. Blood samples of 120 patients were evaluated. All of the patients were under 15 years of age at the time of their treatment at public hospitals in the city of Recife, Brazil (between January of 2003 and August of 2005). Attending physicians at the hospitals diagnosed TB based on the criteria recommended by the American Thoracic Society. The nPCRamplified a 123-bp fragment with outer oligonucleotides (IS1/IS2) and, in the subsequent reaction, using inner oligonucleotides (IS3/IS4), generating an 81-bp amplicon. Results: Active or latent TB was found in 65 patients,TB was ruled out in 28 suspected cases, and 27 patients were TB-free (controls). The sensitivity of nPCR was26.15% and was significantly higher for the extrapulmonary form of the disease (55.56%) than for the pulmonary form (18.18%). The specificity was 92.73%. Conclusions: Despite the difficulties in diagnosing TB in children and the low number of cases evaluated in the present study, nPCR in blood samples proved to be a rapid and specifictechnique, albeit one with low sensitivity. In order to establish its true usefulness in the diagnosis of paucibacillary forms, especially extrapulmonary TB, further studies need to be carried out with a larger sample of children and analyzing biological specimens other than blood.

[Differentiation of micobacteria by multiplex PCR]. / Diferenciação de micobactérias por PCR multiplex.

This study aimed to optimize a method based on the polymerase chain reaction - multiplex PCR - for differentiation of mycobacteria species of interest for public health. The multiplex PCR was based on simultaneous amplification of the hsp65 gene, which is present in all species of the Mycobacterium genus, the dnaJ gene, which is present only in Mycobacterium tuberculosis and Mycobacterium avium and the IS6110 insertion sequence, which is present in the Mycobacterium tuberculosis complex, generating amplicons of 165 bp, 365 bp and 541 bp, respectively. The detection limit was 1 fg for the hsp65 target, 100 pg for dnaJ and 0.1 fg for IS6110. The multiplex PCR detected down to 100 pg of DNA of Mycobacterium tuberculosis. The system was shown to be specific and sensitive for detection of Mycobacterium tuberculosis, Mycobacterium bovis, Mycobacterium avium and Mycobacterium smegmatis. The results obtained using reference strains of mycobacteria showed that multiplex PCR may be a fast, sensitive and specific tool for differentiation of mycobacteria.

Espondilite tuberculosa em adolescente / Tuberculous spondylitis in teenager

Relata-se o caso de uma adolescente com tuberculose osteoarticular em coluna lombossacral, uma localização incomum. O seu diagnóstico permanece um desafio por apresentar sintomas gerais inespecíficos e lesões ósseas que podem ser confundidas com outras afecções. A doença é degenerativa e de prognóstico reservado. São discutidos aspectos clínicos, laboratoriais e de imagem, incluindo tomografia computadorizada e ressonância magnética. A reação em cadeia da polimerase, usando o marcador IS 6110 para M. tuberculosis, foi positiva, sugerindo fortemente a presença do patógeno. Este ensaio é particularmente indicado quando se exige um diagnóstico de tuberculose rápido e sensível.

Development of a single tube hemi-nested PCR for genus-specific detection of Plasmodium in oligoparasitemic patients.

Primers targeting the Plasmodium small-subunit (SSU) rDNA were designed to amplify DNA from P. vivax, P. falciparum, P. malariae, and P. ovale, using conventional PCR, two-step nested PCR (HNPCR), and single tube hemi-nested PCR (STHNPCR). The limit of detection of parasite DNA for the conventional PCR, HNPCR, and STHNPCR were 10 pg, 0.01 pg, and 0.1 pg, respectively, indicating that the STHNPCR is 100-fold more sensitive than conventional PCR, and only 10 times less sensitive than HNPCR. In addition, the detection limit was also defined using blood from a patient infected with P. falciparum. Using the saponin method, the detection limit of the conventional PCR, HNPCR, and STHNPCR were 70, 0.7, and 0.07 parasites/microl, respectively. Finally, the three techniques were evaluated using blood from 30 patients receiving antimalarial treatment, and negative by microscopy and conventional PCR. The HNPCR could still detect specific DNA in 16/30 patients, whereas STHNPCR detected parasite DNA in 10/30 patients, but the difference was not statistically significant. No significant correlation was found between presence of clinical manifestations and presence of parasite DNA, detected by either HNPCR or STHNPCR. We conclude that these sensitive molecular diagnostic systems can be used for the diagnosis of asymptomatic oligoparasitemic patients.

Prevalência das enteroparasitoses nas vilas periéricas da grnde Porto Alegre, nos assentamentos de trabalhadores rurais e na cidade de Arroio dos Ratos, no Estado do Rio Grande do Sul / Survey of intestinal parasites among school students inhabitants of Porto Alegre Metropolitan area and among rural communities of Rio Grande do Sul State

Realizou-se um trabalho intgrado de pesquisa e extensão comunitária com o objetivo de avaliar a prevalência das enteroparasitoses e das condições sócioeconômicas e sanitárias da população residente em 33 vilas periféricas da região metropolitana de Porto Alegre, em 3 assentamentos de trabalhadores rurais e na cidade de Arroio dos Ratos no Estado do Rio Grande do Sul. Esse estudo foi realizado durante o período de 1965 e 1996 em 17951 pessoas, pertencentes a um grupo etário de zero a 15 anos, todos alunos das escolas públicas e em mais dois grupos etários: um e 16 a 20 anos e outro com mais de 20 anos. As amostras fecais foram examinadas pela técnica d Hoffman, Pons e Janer. Das pessoas examinadas, 6,0% (11.855) estavam infectadas por uma ou mais espécies de parasitos intestinais, dos quais 31% (5.581)apresentaram apenas uma espécie de parasito, enquanto que o poliparasitismo representou 35% das respostas, em um total de 6.277 combinações. O maior percentual geral de infecção obtido para nermatóides e cestóides foi de 43,1% (7.092) para Trichuris trichiura e, entre os protozoários, a Giardia lamblia com 17,1% (2.820). As associações mais frequentes, em infecções concomitantes por helmintos e protzoários foram: Ascaria lumbricoides e T trichiura com ,2% (1.835), T trichiura e G lamblia com 8,5% (537) e Entamoeba coli e G lamblia com 2,0% (124). Os resultados obtidos nesse inquérito levam a sugerir necessidade de proporcionar às pessoas residentes nas vilas periféricas, nos assentamentos de trabalhadores rurais e na cidade de Arroio dos Ratos uma Campanha d educação sanitária e, paralelamente, o desenvolvimento de medidas administrativas, visando saneamento básico.