Detection of drug susceptibility in rapidly growing mycobacteria by resazurin broth microdilution assay.

The susceptibility of rapidly growing mycobacteria (RGM) to linezolid and ciprofloxacin was evaluated by using resazurin as a growth indicator. The assay with resazurin supplemented medium performed as well as its addition to the medium at reading time and was efficient for the determination for the susceptibility profile in RGM.

First baseline of circulating genotypic lineages of Mycobacterium tuberculosis in patients from the brazilian borders with Argentina and Paraguay.

BACKGROUND: At the triple border Brazil/Paraguay/Argentina there is easy mobility from one city to another for economic and tourism activities. This constant and fast population mobility is mainly to visit Iguazu Falls, in the Iguazu River, on the border of the Brazilian state of Paraná and the Argentina. As the incidence of tuberculosis is high in this setting, our study aimed to establish a first baseline of circulating genotypic lineages of Mycobacterium tuberculosis. METHODOLOGY/PRINCIPAL FINDINGS: This study included 120 patients from 10 cities in southwestern Paraná, Brazil with pulmonary symptoms, from July 2009 to July 2011. Information about sex, age, clinical features and address was collected by reviewing the national tuberculosis notification database. Of these, 96 (80%) isolates were identified as M. tuberculosis and 22 (22.9%) were drug resistant (20, 20.8% INH mono-resistant and 2, 2.1% multidrug-resistant). All isolates were subjected to genotyping by Spoligotyping and MIRU-VNTR typing. The distribution of the isolates analyzed by spoligotyping revealed 30 distinct patterns. The four mainly detected clades were Latin American and Mediterranean (LAM), ill-defined T, Haarlem (H) and S. The MIRU-VNTR showed 85 distinct patterns. Spoligotyping combined to MIRU-VNTR allowed 90 distinct patterns. CONCLUSIONS/SIGNIFICANCE: Our study demonstrated that there is significant molecular diversity in circulating M. tuberculosis, with predominance of the LAM and T clades in cities of southwestern Paraná, Brazil, bordering Argentina and Paraguay.

Use of the Ogawa-Kudoh method to isolate mycobacteria in a tuberculosis reference laboratory in northwestern Paraná, Brazil

Culturing is the gold standard method for confirming a diagnosis of tuberculosis (TB). The Brazilian Ministry of Health recently proposed the use of the Ogawa-Kudoh method for sputa cultures to detect Mycobacterium tuberculosis. The aim of the present study was to evaluate 8 years of using the Ogawa-Kudoh method in a TB reference laboratory in northwestern Paraná, Brazil. The present study consisted of a retrospective analysis of sputa cultures records for the detection of mycobacteria using the Ogawa-Kudoh method in the Laboratory of Medical Bacteriology, Laboratory of Teaching and Research in Clinical Analysis (LEPAC), State University of Maringá, from July 2003 to September 2011. The following variables were analyzed: Ziehl Neelsen (Z-N) smears and cultures results and the age and gender of the patients. Sputa samples from 3,231 patients with suspected TB were analyzed. Of these, 67.17% were male with an average age of 45.58 years. Of the total number of Z-N-negative samples (n=2,949), 42 (1.42%) were positive for M. tuberculosis (p >0.05). The Ogawa-Kudoh method is an excellent tool for diagnosing pulmonary TB. It is easy to perform, requires less biosafety equipment than the Petroff method, has a low cost, and has good sensitivity for detecting of M. tuberculosis.

A cultura é o método padrão ouro para confirmação da tuberculose (TB). O Ministério da Saúde Brasileiro propôs, recentemente, a utilização do método de Ogawa-Kudoh para cultura de escarro na detecção de Mycobacterium tuberculosis. O objetivo deste estudo foi avaliar oito anos de utilização do método de Ogawa-Kudoh na rotina de um laboratório de referência na região noroeste do Paraná, Brasil. Realizou-se estudo retrospectivo dos registros das culturas de escarro para a detecção de micobactérias, usando o método Ogawa-Kudoh conduzido no Laboratório de Bacteriologia Médica, Laboratório de ensino e pesquisa em Análises Clínicas (LEPAC) da Universidade Estadual de Maringá (UEM), de Julho de 2003 a Setembro de 2011. As seguintes variáveis foram analisadas: esfregaço Ziehl Neelsen (Z-N), cultura, idade e sexo do paciente. Analisaram-se 3.231 amostras de escarro de pacientes com suspeita de tuberculose. Destes, 67,17% eram do sexo masculino com idade média de 45,58 anos. Do total de amostras Z-N negativas (n=2.949), 42 amostras (42/2949, 1,42%) apresentaram cultura positiva para M. tuberculosis (p>0,05). A utilização do método Ogawa-Kudoh representa excelente ferramenta para o diagnóstico precoce da TB pulmonar. É de fácil execução, requer menos equipamentos de biossegurança do que o método de Petroff, apresenta baixo custo e boa sensibilidade para detecção de M. tuberculosis.