Recent Trends in Clinically Significant Nontuberculous Mycobacteria Isolates at a Korean General Hospital

Lung disease caused by nontuberculous mycobacteria (NTM) represents an increasing proportion of all mycobacterial diseases. We investigated recent occurrences of NTM and evaluated the clinical significance of NTM isolates from 752 respiratory specimens collected from patients at National Health Insurance Service Ilsan Hospital between January 2007 and May 2011. Specimens were incubated on solid and liquid media (BACTEC MGIT 960, BD, USA) for 6-8 weeks, and PCR and reverse blot hybridization were performed (REBA Myco-ID, Molecules & Diagnostics, Korea). Clinical features of the patients were reviewed through medical records. The most frequently isolated organism was Mycobacterium avium (46.7%), followed by M. intracellulare (14.8%), M. fortuitum (7.2%), and M. abscessus (6.6%). The most common mycobacteria among definitive cases of NTM lung disease were M. avium (42/351, 12.0%), M. intracellulare (19/111, 17.1%), M. abscessus (11/50, 22.0%), M. massiliense (4/13, 30.8%), and M. fortuitum (4/54, 7.4%). Clinically significant cases of NTM lung disease increased from 4 patients in 2007 to 32 in 2011. The mean patient age was 64 yr (range: 35-88 yr), and 58 (64%) patients were women. Patients suffered from cough, productive sputum, and hemoptysis. In summary, the most common mycobacteria causing NTM lung disease were M. avium and M. intracellulare; however, cases of M. massiliense and M. abscessus infection are on the rise in Korea.

Nonspecificity of 35 kDa protein: A proposed marker for the differential diagnosis of M. avium infection in the Indian population.

Objective: The subunit vaccine strategies and development of various diagnostic reagents for Mycobacterium avium infection relies on the presence of secreted, species-specific mycobacterial antigens. The M. avium 35 kDa protein has been suggested as a candidate for vaccine/diagnostic reagent, specifically for M. avium infection. The present study was conducted to evaluate the diagnostic specificity of the M. avium 35 kDa protein in the Indian population. Materials and Methods: Culture filtrate proteins were isolated by growing the bacilli in modified Youman's medium. The 35 kDa protein was purified by high-resolution preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis and a blast search was carried out. Western blotting was performed with either monoclonal antibody CS-38 or serum samples of tuberculosis (TB) patients. The 35 kDa-specific immunoglobulin G antibody titer was estimated in the sera of TB patients and healthy individuals by indirect enzyme-linked immunosorbent assay (ELISA). Results: Despite the absence of gene for the 35 kDa protein, the sera of TB patients and TB patient's contacts nonspecifically recognize it. Of 109 TB patients tested, the sera of 84 patients in ELISA (percentage recognition = 87.5%) and 27 of 29 TB patients tested in western immunoblotting (percentage recognition = 93.10%) recognized the M. avium 35 kDa protein, while with sera of TB patient's contacts, the recognition was 50%. Conclusion: Contrary to Western studies, the M. avium 35 kDa protein does not seem to be a good candidate for the specific diagnosis of M. avium infection in the Indian population.

Distribución de patrones PRA en aislamientos clínicos del complejo Mycobacterium avium procedentes de España y Suramérica

La infección por el complejo Mycobacterium avium (MAC) es la infección sistémica más frecuente en la fase terminal del SIDA. Las sondas de ADN disponibles en el mercado para la identificación de micobacterias son muy precisas pero extremadamente costosas. Por eso, la mayoría de los laboratorios clínicos de Latinoamérica aún tipifican micobacterias mediante pruebas fenotípicas que son lentas, laboriosas y poco precisas. En este trabajo se aplicó el análisis del polimorfismo de los fragmentos de restricción del gen hsp65 (PRA) a la identificación de MAC en 163 aislamientos clínicos procedentes de España y Suramérica. El genotipo PRA predominante en cada país fue: M. avium tipo I en Argentina (23/42, 55%) y Brasil (48/72, 67%), M. avium tipo II en España (18/26, 69%) y M. avium tipo III en Colombia (10/23, 43%). Este último genotipo, que aún no fue descrito fuera del continente americano, resultó muy infrecuente en los otros tres países del estudio. Se discuten ventajas e inconvenientes de la aplicación del PRA al diagnóstico micobacteriológico.

Distribution of PRA patterns of clinical isolates of the Mycobacterium avium complex from Spain and South America Mycobacterium avium complex (MAC) infections are the most frequent systemic infections associated with advanced AIDS. DNA probes for accurate identification of mycobacteria are available but are very expensive in many Latin American settings. Consequently, most Latin American diagnostic laboratories employ inaccurate and outdated tests for mycobacteria identification. Therefore, PCR restriction analysis (PRA) of the hsp65 gene was evaluated for the identification of 163 MAC human isolates originated from Spain and South America. The predominant PRA type in each country was: M. avium type I in Argentina (23/42, 55%) and Brazil (48/72, 67%), M. avium type II in Spain (18/26, 69%) and M. avium type III in Colombia (10/ 23, 43%). The Colombia frequency is noteworthy, since the PRA type III was quite infrequent in the other three countries. Furthermore, its presence has not been reported outside the Americas. The advantages and disadvantages of PRA in diagnostic mycobacteriology are discussed.

Perfil bacteriológico da tuberculose pulmonar na regiäo de Campinas e das Diretorias Regionais de Saúde XII, XV e XX - 1999/2000 / Bacteriologic profile of lung tuberculosis in the Campinas Region and XII, XV and XX Health Regional Department,-1999/2000

Com o objetivo de avaliar o diagnóstico bacteriológico e controle de tratamento da tuberculose, os autores analisaram, nos anos de 1999 e 2000, os exames processados pelo Instituto Adolfo Lutz de Campinas e laboratórios de sua abrangência das Diretorias Regionais de Saúde (DIR)-XII, XV e XX, que atendem 93 municípios. Neste período foram realizados 53.341 baciloscopias, em 3.781 (7,1 por cento) foram detectados a presença de BAAR com positividade 4,9 por cento para diagnóstico, 1,2 por cento para controle de tratamento e 1 por cento para o sem informação quanto ao quesito diagnóstico e ou controle de tratamento. Foram realizadas 7.603 (14,3 por cento) culturas, havendo isolamento de microbactérias em 1.134 (14,9 por cento) amostras, 13,2 por cento para diagnóstico, 1,4 por cento para controle de tratamento e 0,3 por cento para o sem informação. Foram identificadas 936 cepas pertencentes ao complexo Mycobacterium tuberculosis e 48 ao complexo M.avium. O perfil de sensibilidade de 381 cepas de M.tuberculosis demonstrou que 78,0 por cento foram sensíveis às drogas testadas e 22,0 por cento resistentes a pelo menos uma droga. As análises destes dados contribuem para as ações do Programa de Controle da Tuberculose, auxiliando na determinação do perfil epidemiológico da doença na regiäo de Campinas e nas DIRs envolvidas. (AU)

With the purpose of evaluating the bacteriological diagnosis and the tuberculosis treatmentcontrol, the authors analyzed, in the years of 1999/2000, the tests processed by the Adolfo Lutz Institutein Campinas (SP), Health Regional Department (DIRS) and laboratories related to it from XII, XV and XX,witch serve 93 towns. During that period 53.341 samples were undertaken, 3.781 (7,1%) detected thepresence of BAAR with positiveness of 4,9% for diagnosis, 1,2% for treatment control and 1,0% for theones without information regarding the diagnosis item or treatment control. 7.603(14,3%) cultures weregrown, with isolation of micobacteria taking place in 1.134 (14,9%); 13,2% for diagnosis, 1,4% for treatmentcontrol and 0,3% for the ones lacking information. 936 heathers belonging to Mycobacterium tuberculosiscomplex and 48 belonging do M. avium complex were identified. The profile of sensitiveness of 381heathers of M. tuberculosis showed that 78% were sensitive to tested drugs used and 22% resisted atleast one drug. That data analyses have contributed to the realizations of the Tuberculosis ControlProgram, helping to determining the epidemiological profile of the illness in the Campinas region andinvolved DIRs. (AU)

Differentiation of Mycobacterium avium Complex Isolated in Korea by DT1-BT6 PCR

Recently, selective PCR method using DT1 and DT6 sequences was introduced to identify and differentiate the Mycobacterium avium complex (MAC) into M. intracellulare and M. avium. We applied this method to 49 MAC clinical isolates identified by biochemical tests. They were differentiated into 39 strains of M. intracelluare and 10 strains of M. avium. Compared to those results obtained by 16S rDNA sequencing, DT1-DT6 PCR method showed 100% specificity. While the sensitivity of DT6 PCR for M. avium was 100%, that of DT1 PCR for M. intracellulare was 84.6%. These results show heterogeneity of M intracellulare Korea clinical isolates from Korea. In conclusion, although the in-house DTl-DT6 PCR is an easy and convenient method in differentiating MAC members, other methods such as 16S rDNA sequencing analysis should be performed for the correct identification, especially of M intracellulare.