RESUMO Contexto Helicobacter pylori tem uma distribuição a nível mundial, e está associado a patogênese de várias doenças do sistema digestivo. O tratamento para a erradicação deste microrganismo envolve a utilização de uma combinação de agentes antimicrobianos, tais como amoxicilina, metronidazol, claritromicina e levofloxacino, combinados com inibidores da bomba de prótons. Embora a terapia atual seja eficaz, uma elevada taxa de fracasso de tratamento tem sido observada, principalmente devido à aquisição de mutações pontuais, um dos principais mecanismos de resistência desenvolvida por H. pylori, relacionado com o uso frequente e/ou inadequado dos antibióticos. Conclusão Esta revisão abordou uma visão geral da resistência às principais drogas utilizadas no tratamento de H. pylori, confirmando a hipótese de que a resistência bacteriana é um fenômeno altamente local e as características genéticas de uma dada população podem influenciar qual terapia é a mais apropriada.

ABSTRACT Background Helicobacter pylori has a worldwide distribution and is associated with the pathogenesis of various diseases of the digestive system. Treatment to eradicate this microorganism involves the use of a combination of antimicrobials, such as amoxicillin, metronidazole, clarithromycin, and levofloxacin, combined with proton pump inhibitors. Although the current therapy is effective, a high rate of treatment failure has been observed, mainly because of the acquisition of point mutations, one of the major resistance mechanisms developed by H. pylori. This phenomenon is related to frequent and/or inappropriate use of antibiotics. Conclusion This review reported an overview of the resistance to the main drugs used in the treatment of H. pylori, confirming the hypothesis that antibacterial resistance is a highly local phenomenon and genetic characteristics of a given population can influence which therapy is the most appropriate.

Abstract: INTRODUCTION: The World Health Organization endorses the BACTEC Mycobacterial Growth Indicator Tube (MGIT)(tm) system as a rapid, sensitive, and specific method to diagnostic of tuberculosis. Here, we compared the performance of this system against Ogawa-Kudoh cultures and microscopy. METHODS: A total of 927 samples were obtained between December 2011 and December 2013 from 652 cases of suspected tuberculosis at the School Hospital of the Federal University of Rio Grande in Brazil. RESULTS: The MGIT system confirmed tuberculosis in more cases in less time. CONCLUSIONS: The MGIT system is an effective tool for early diagnosis of tuberculosis, especially in patients with HIV/AIDS.

Asymptomatic meningococcus carriers in hospitals is a risk factor for acquiring meningococcal disease. Meningococcal carrier (MC) frequency was investigated in oropharyngeal swab samples collected from 200 staff members at a teaching hospital from Brazil. MC prevalence was 9 % (95 % CI 5-13 %). Risk factors associated with MC were: mean age of 26.5 years, male gender, bar attendance frequency and number of persons/house. Of 18 isolated meningococcal strains, 14 were non-groupable (NG), 3 corrresponded to serogroup B and 1 to serogroup 29E. The frequency of serotypes and serosubtypes was heterogenous, with a slight predominance of serotypes 4 and 7 and serosubtypes P1.7 and P1.5. Most strains (n = 13) were susceptible to the antimicrobials tested. The ctrA gene (PCR) was identified in 9 (64.3 %) of the 14 NG strains, suggesting virulence in most of the NG isolated strains. Therefore, a constant surveillance of these asymptomatic carriers is required.

Los portadores asintomáticos de meningococos en hospitales son un factor de riesgo (FR) para adquirir la enfermedad meningocócica. La frecuencia de portadores de meningococos fue determinada a través de colecta orofaríngea en personal de un hospital de Brasil (n = 200). La prevalencia de portadores fue del 9 % (IC del 95 %, 5-13 %). Los FR asociados al estado de portador fueron los siguientes: edad promedio 26,5 años, sexo masculino, hábito de frecuentar bares y número de personas/casa. Entre las 18 cepas de meningococos aisladas, 14 eran no agrupables (NG), 3 correspondieron al serogrupo B y una al 29E. La frecuencia de los serotipos y serosubtipos fue heterogénea, con un ligero predominio de los serotipos 4 y 7 y de los serosubtipos P1.7 y P1.5. La mayoría de las cepas (n = 13) fueron sensibles a los antimicrobianos estudiados. El gen ctrA fue identificado por PCR en 9 (64,3 %) de las 14 cepas NG, lo que sugiere virulencia en la mayoría de las cepas NG aisladas. Por lo tanto, se requiere una vigilancia constante de estos portadores asintomáticos.

Introducción. Los informes sobre Mycobacterium tuberculosis resistente a múltiples fármacos están aumentando a nivel mundial y los laboratorios toman cada vez más conciencia sobre la necesidad de realizar pruebas de sensibilidad a fármacos. Debido al tiempo prolongado que se requiere para hacerlas, se han propuesto nuevos enfoques para la detección rápida de resistencia a los medicamentos, tales como la prueba de la nitrato reductasa. Objetivo. En este estudio se propuso una prueba de sensibilidad a fármacos colorimétrica, rápida y directa, en un formato de microplacas utilizando medio sólido. Materiales y métodos. La precisión del diagnóstico se evaluó mediante la comparación del método de las proporciones con la prueba de la nitrato reductasa directa en placas. Se descontaminaron muestras positivas congeladas de esputo y se procesaron mediante el método de Petroff. La suspensión ya descontaminada se utilizó para hacer la prueba de la nitrato reductasa directa en medio 7H11, utilizando 1 µg/ml de rifampicina, 0,2 µg/ml de isoniacida, 2 µg/ml de ofloxacina, 6 µg/ml de de kanamicina, 2 µg/ ml de amicacina y 10 µg/ml de capreomicina. Se analizaron 84 muestras y los resultados del 69 % de ellas estuvieron disponibles en 21 días. Resultados. La sensibilidad y la especificidad de la prueba comparada con el método de las proporciones fueron de 98,5 y 100 % para la isoniacida, de 98,3 y 96,2 % para la rifampicina, de 91,7 y 100 para la kanamicina, de 78,8 y 97,3 % para la ofloxacina y de 100 y 100 % para la amikacina y la capremicina, respectivamente. Conclusión. Este nuevo formato de la prueba de la nitrato reductasa directa es un método preciso, rápido y económico para determinar el perfil de sensibilidad de M. tuberculosis y puede convertirse en una alternativa para los países con recursos limitados.

Introduction: Reports of Mycobacterium tuberculosis resistant to multiple drugs are increasing globally and laboratories are becoming increasingly aware of the need for drug susceptibility testing. In recent years, due to the long time required by conventional drug susceptibility testing, new approaches have been proposed for faster detection of drug resistance, such as the nitrate reductase assay, considered fast and inexpensive, making it a good diagnostic tool for low resource countries. Objective: The present study proposed a fast direct colorimetric drug susceptibility testing method in a microplate format using solid medium. Materials and methods: The diagnostic accuracy was evaluated by comparing the proportion method with the direct nitrate reductase assay in plates. Frozen sputum samples, known to be positive, were decontaminated and processed by Petroff method. The decontaminated suspension was used to perform direct nitrate reductase assay in 7H11 medium using 1 µ g/ml rifampicin (RIF), 0.2 µ g/ml isoniazid (INH), 2 µ g/ml ofloxacin (OFX), 6 µ g/ml kanamycin (KAN), 2 µ g/ml amikacin (AMK) and 10 µ g/ml capreomycin (CAP). Eighty-four samples were tested and the results for 69% of them were available within 21 days. Results: The sensitivity and specificity compared to the proportion method, was 98.5% and 100% for INH, 98.3% and 96.2% for RIF, 91.7% and 100% for KAN, 78.8% and 97.3% for OFX, 100% and 100% for AMK and CAP, respectively. Conclusion: The results lead to the conclusion that direct nitrate reductase assay, in this new format, is an accurate, quick and inexpensive method to determine the susceptibility profile of M. tuberculosis and may become an alternative for countries with limited resources.

Bovine tuberculosis is a major infectious disease of the cattle. In this study, 85 M. bovis isolates from 162 lymph nodes, obtained from a herd of cattle on a farm in southern Brazil, were evaluated using spoligotyping and VNTR. The strains were grouped into five clusters and five orphans, showing a heterogenic genetic profile, what could represent diverse geographic origins of the introduced cows and/or the frequent movement of cattle between different properties.

A sublineage of Mycobacterium tuberculosis called RD Rio was described in 2007. Although only recently described, this strain may have been present previously in the population, and its identification in clinical isolates will elucidate bacterial transmission dynamics and host-pathogen interactions. This study evaluated the clonal diversity of the RD Rio sublineage in clinical isolates from Rio Grande-RS obtained between 1998 and 2001. Among the 45 samples analyzed by the MIRU-VNTR method, there were six clusters with two samples each and 33 orphan strains with unique pattern. The strains were distributed across several different lineages including LAM (34.04%), X (14.89%), Haarlem (12.77%), UgandaI (10.64%), S (4.26%), NEW-1 (2.13%) and Cameroon (2.13%); 14.89% of the strains matched to multiple lineages. RD Rio strains were present in 28.9% of the samples and 81.25% of the identified strains belonged to the LAM family. The high clonal diversity observed in this study is a constant feature in this region. The RD Rio sublineage has been in Rio Grande-RS since 1998. The continued monitoring of RD Rio in clinical isolates will enhance the understanding of its epidemiological significance.

IntroductionHelicobacter pylori infection is associated with gastro-duodenal diseases. Genes related to pathogenicity have been described for H. pylori and some of them appear to be associated with more severe clinical outcomes of the infection. The present study investigates the role of cagE as a pathogenicity biomarker of H. pylori compare it to cagA, vacA, iceA and babA2 genes and correlate with endoscopic diagnoses.MethodsWere collected biopsy samples of 144 dyspeptic patients at the Hospital of the Federal University of Rio Grande, Rio Grande do Sul, Brazil. After collection, the samples were sent for histological examination, DNA extraction and detection of all putative pathogenicity genes by PCR.ResultsOf the 144 patients undergoing endoscopy, 57 (39.6%) presented H. pylori by histological examination and PCR by detection of the ureA gene. Based on the endoscopic diagnoses, 45.6% (26/57) of the patients had erosive gastritis, while 54.4% (31/57) had enanthematous gastritis. The genes cagA, cagE, vacAs1/m1, vacAs1/m2 and iceA1 were related to erosive gastritis, while the genes vacAs2/m2, iceA2 and babA2 were associated to enanthematous gastritis. We found a statistically significant association between the presence of cagE and the endoscopic diagnosis. However, we detect no statistically significant association between the endoscopic diagnosis and the presence of cagA, vacA, iceA and babA2, although a biological association has been suggested.ConclusionsThus, cagE could be a risk biomarker for gastric lesions and may contribute to a better evaluation of the H. pylori pathogenic potential and to the prognosis of infection evolution in the gastric mucosa.

INTRODUÇÃO: O controle da tuberculose (TB) está relacionado com a disponibilidade de métodos de diagnóstico microbiológico qualificados, no entanto a microscopia com a sua limitada sensibilidade é o único método disponível em muitos locais.O objetivo deste estudo foi avaliar a introdução da cultura, teste de sensibilidade aos antimicrobianos (TSA) e genotipagem na rotina de um Programa Municipal de Controle da Tuberculose. MÉTODOS:A baciloscopia direta do escarro e cultura em Ogawa-Kudoh foram realizadas em 1.636 amostras de 787 pacientes. O TSA das culturas positivas foi realizado pelo método de microdiluição e a genotipagem por Mycobacterial Interspersed Repetitive Units - Variable Number Tandem Repeat (MIRU-VNTR). RESULTADOS:Foram identificados 91 pacientes com TB, com a cultura aumentando em 32% a detecção de casos em comparação com a microscopia; a resistência adquirida foi de 3,3% e a genotipagem mostrou alta diversidade genética. CONCLUSÕES: O cultivo em Ogawa-Kudoh contribuiu significativamente para o aumento na detecção de casos e é adequado para ser implementado em locais com poucos recursos. A taxa de resistência adquirida foi menor do que a relatada em recente inquérito nacional. A alta diversidade genética está possivelmente relacionada à alevada prevalência de TB na população, detecção precoce e tratamento adequado dos pacientes.A interação entre a pesquisa e serviço de saúde pública é importante para reorientar a prática, transferir tecnologia e melhorar o controle da TB.

INTRODUCTION: Tuberculosis (TB) control is linked to the availability of qualified methods for microbiological diagnostics; however, microscopy with limited sensitivity is the only method available in many locations. The objective of this study was to evaluate the introduction of culture, drug susceptibility testing (DST), and genotyping in the routine of a Municipal Program of Tuberculosis Control. METHODS: Direct microscopy of sputum and culture in Ogawa-Kudoh were performed on 1,636 samples from 787 patients. DST of positive cultures was performed by resazurin microtiter assay and genotyping by mycobacterial interspersed repetitive units-variable number tandem repeat. RESULTS: A total 91 patients with TB were identified. The culture increased case detection by 32% compared with the microscopy; acquired resistance was 3.3% and the genotyping showed high genetic diversity. CONCLUSIONS: Ogawa-Kudoh contributed significantly to the increase in case detection and is suitable for implementation in poor-resource locations. The acquired resistance rate was lower than that reported in a recent Brazilian survey. The high genetic diversity is possibly related to the high TB prevalence in the population, as well as to early detection and suitable treatment of patients. The interaction between research and health care is important for reorienting the practice, transferring technology, and improving TB control.

We standardized a method to evaluate the growth kinetics of Mycobacterium tuberculosis by measuring quantitatively the reduction of resazurin by spectrophotometry. Growth curves and the rate of growth of twenty-one M. tuberculosis clinical isolates were determined. The method showed technical simplicity and is inexpensive to assess the fitness of each isolate.

A tuberculose permanece como uma séria doença infecciosa, com distribuição mundial, alta morbidade e mortalidade, ocorrendo principalmente em paises com baixa condição econômica. O estado de emergência da tuberculose causada por cepas resistentes e multirresistentes tornou-se uma importante ameaça para o tratamento e programas de controle da tuberculose. Uma rápida detecção de cepas resistentes permitirá a implantação de um tratamento adequado e contribuirá para controlar a disseminação destas cepas. Este estudo avaliou a performace do ensaio nitrato redutase em meio sólido (NRA-LJ) e meio líquido (NRA-7H9), para determinar a sensibilidade frente aos fármacos antituberculosos de primeira linha: isoniazida (INH), rifampicina (RMP), etambutol (EMB) and estreptomicina (SMR). Ambos os métodos, NRA-LJ e NRA-7H9, foram avaliados com 18 cepas com conhecido perfil de sensibilidade. O ensaio de microplaca com resazurina (REMA) foi utilizado como método de referência. A concordância observada entre NRA-7H9 and REMA foi de 100% para os quatro fármacos testados. Quando o método NRA-LJ foi comparado com o REMA, a sensibilidade e especificidade para INH RMP e SMR foram de 100%, 100%, 85,7%, 76,9% e 80%, 100%, 75% and 80%, respectivamente. Dos 57 isolados clinicos de M. tuberculosis avaliados por NRA-7H9 e REMA, 56 (98.2%) foram sensíveis a todos antibióticos testados (INH, RMP, EMB e SMR) pelo método NRA-7H9, enquanto três destas cepas foram resistentes para INH pelo REMA. Uma cepa mostrou resistência para INH e RMP por ambos os métodos, e CMI de 1,0 µg/ml para INH para ambos os métodos, enquanto CMI de 1,0 e 2,0 µg/ml para RMP pelo REMA e NRA-7H9, respectivamente. Os três ensaios mostraram um alto nível ded concordância para uma rápida detecção de resistência a rifampicina e isoniazida. Com relação à rapidez na obtenção dos resultados, a detecção na mudança de cor nos métodos NRA é imediata enquanto para o método REMA é necessário incubar overnight. Os métodos NRA podem representar uma alternativa, de baixo custo e rápida detecção de resistência, em países com poucos recursos.

Tuberculosis remains as a serious infection disease of worldwide distribution, with high morbidity and mortality, mainly in low socio-economic condition countries. The state of emergency of tuberculosis caused by the resistant and multidrug-resistant (MDR) strains, became the main threat to the tuberculosis treatment and control programs. A fast detection method for the resistant strains will allow the implementation of an adequate treatment and contribute for controlling the dissemination of these resistant strains. This study evaluated the performance of the nitrate reductase assay in solid (NRA-LJ) and liquid (NRA-7H9) media, to determine the susceptibility to first line anti-tuberculosis drugs: isoniazid (INH), rifampicin (RMP), ethambutol (EMB) and streptomycin (SMR). Both methods NRA-LJ and NRA-7H9 were evaluated among 18 strains with a known susceptibility profile. The resazurin microtiter assay (REMA) was performed as a reference method. One hundred percent of accordance was observed between NRA-7H9 and REMA for the four tested drugs. When the NRA-LJ method was compared to REMA, the sensitivity and the specificity to INH, RMP, EMB and SMR were 100%, 100 %, 85.7%, 76.9% and 80%, 100%, 75% and 80%, respectively. From the 57 clinical isolates of M. tuberculosis evaluated by NRA-7H9 and REMA, 56 (98.2%) were sensitive to all antibiotics tested (INH, RMP, EMB and SMR) by the NRA-7H9 method, while three of these strains were resistant to INH by REMA. One strain showed resistance to INH and RMP for both methods, and MIC of 1.0 µg/ml to INH for both methods, while MIC of 1.0 and 2.0 µg/ml to RMP for REMA and NRA-7H9, respectively. The three assays showed a high level of agreement for rapid detection of rifampicin and isoniazid resistance. Regarding rapidness, the detection of color change in the NRA method is within instants as compared to the overnight incubation required for the REMA test. NRA might represent an inexpensive and alternative assay for rapid detection of resistance in low-income countries.