[Show abstract][Hide abstract] ABSTRACT: We evaluated a new line probe assay (LiPA) kit to identify Mycobacterium species and to detect mutations related to drug resistance in Mycobacterium tuberculosis. A total of 554 clinical isolates of Mycobacterium tuberculosis (n = 316), Mycobacterium avium (n = 71), Mycobacterium intracellulare (n = 51), Mycobacterium kansasii (n = 54), and other Mycobacterium species (n = 62) were tested with the LiPA kit in six hospitals. The LiPA kit was also used to directly test 163 sputum specimens. The results of LiPA identification of Mycobacterium species in clinical isolates were almost identical to those of conventional methods. Compared with standard drug susceptibility testing results for the clinical isolates, LiPA showed a sensitivity and specificity of 98.9% and 97.3%, respectively, for detecting rifampin (RIF)-resistant clinical isolates; 90.6% and 100%, respectively, for isoniazid (INH) resistance; 89.7% and 96.0%, respectively, for pyrazinamide (PZA) resistance; and 93.0% and 100%, respectively, for levofloxacin (LVX) resistance. The LiPA kit could detect target species directly in sputum specimens, with a sensitivity of 85.6%. Its sensitivity and specificity for detecting RIF-, PZA-, and LVX-resistant isolates in the sputum specimens were both 100%, and those for detecting INH-resistant isolates were 75.0% and 92.9%, respectively. The kit was able to identify mycobacterial bacilli at the species level, as well as drug-resistant phenotypes, with a high sensitivity and specificity.
Journal of clinical microbiology 12/2011; 50(3):884-90. · 4.16 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background: Tuberculous meningitis (TBM) needs prompt diagnosis and adequate treatment because of its rapidly progressive and uniformly fatal course. It is well known that adjunctive treatment with corticosteroids may reduce the risk of disability or death among adults with TBM. Meanwhile, there is “latent tuberculous meningitis”, that is only inflammatory changes of cerebrospinal fluid (CSF) without central nervous system (CNS) symptoms in patients with disseminated tuberculosis. It is difficult to diagnose latent TBM due to no CNS symptoms. Diagnosis of it, however, might lead to better prognosis due to adequate antituberculosis treatment with corticosteroids.
Methods: A total of 18 adult patients, who were diagnosed as disseminated tuberculosis and done by CSF analysis from May 2008 to April 2011, were retrospectively reviewed to investigate the clinical features of latent TBM. TBM was diagnosed by inflammatory changes of CSF (cells>10 /μl or protein content > 50mg/dl). Among 18 patients, 4 ones were diagnosed as TBM, including 2 CNS symptomatic TBM cases and 2 latent TBM ones. All 4 patients with TBM were treated with both multiagent antituberculosis chemotherapy and corticosteroids. Patients were divided into “symptomatic TBM” and “latent TBM”. Background, clinical features, CSF test results were compared between these 2 groups.
Results: There was no significant differences in clinical background, including age, severity of disseminated disease and test results in CSF, between symptomatic TBM group and latent TBM group (Age: 56±8 years and 62±7 years, CSF results: leukocyte count 36±13 /μl and 52±9 /μl, protein levels 70±8 mg/dl and 108±0 mg/dl, glucose levels 49.5±3.5 mg/dl and 49±7.0 mg/dl, respectively in symptomatic TBM group and latent TBM group). The latter, however, tends to be older and to show more cells and protein levels in CSF. One of 2 patients with symptomatic TBM left CNS sequelae, but all 2 patients with latent TBM recovered without seruelae.
Conclusion: We reported disseminated tuberculous disease with clinically latent meningitis. It is suggested that we might apply aggressive spinal tap examination to CNS asymptomatic patients with disseminated TB.
Infectious Diseases Society of America 2011 Annual Meeting; 10/2011
[Show abstract][Hide abstract] ABSTRACT: Background:COBAS TaqMan MTB/MAI (Roche Diagnostics, CTM), which is a real-time PCR assay for Mycobacterium tuberculosis complex (MTB), Mycobacterium avium (MAV) and Mycobacterium intracellulare (MIN), has been developed as the successor model of AMPLICORE Mycobacterium PCR (Roche Diagnostics, AMP). CTM can complete the assay in fewer hours (about three hours) than AMP. The purpose of this study is to evaluate the usefulness of COBAS TaqMan assay, comparing it tothe existing COBAS AMPLICOR assay in culture-positive cases.
Methods: Consecutive clinical respiratory specimens from 412 culture-positive patients were examined by AMP assay between Jan 2007 and Dec 2009 (AMP specimens). Consecutive specimens from 181 culture-positive cases were tested by CTM assay between Jan 2010 and Dec 2010 (CTM specimens). The test performances of those assays were compared.
Results:There were nosubstantive differences in results of acid-fast smear, liquid culture, and solid culture between AMP specimens and CTM ones. Results of PCR detection rate in MTB, MAV and MIN were 77.23% (156/202), 62.60% (82/131), 62.03% (49/79) by AMP and 82.35% (56/68), 60.29% (41/68), 60.00% (27/45) by CTM, respectively There was no difference between both assays. In smear-negative cases, results of PCR detection rate in MTB, MAV and MIN were 54.55%, 46.67%, 47.27% by AMP and 63.64%, 46.00%, 40.00% by CTM. These also showed no difference.
Conclusion:This study was not a prospective head-to-head one. But AMP specimens and CTM ones showed similar characteristics of mycobacteriology. This study showed that both assays might have equivalent performance in detecting MTB, MAV and MIN. COBAS TaqMan and COBAS AMPLICORE assays for MTB, MAV and MIN might have equivalent performance. The former is suggested to be more useful because of increased rapidity and convenience.
Infectious Diseases Society of America 2011 Annual Meeting; 10/2011
[Show abstract][Hide abstract] ABSTRACT: We report one Japanese familial line in which there were three pulmonary MAC patients and one suspected patient over two generations, most of whom were diagnosed with the nodular/bronchiectatic type. In all patients, life circumstances and bacterial strains differed at the time of diagnosis. This suggests that the genes thought to affect patient susceptibility to pulmonary MAC disease may be involved in this family line. Comprehensive genotypic analysis of the CFTR gene, HLA typing, and analysis of the NRAMP1 polymorphisms were performed in seven members of this family. The results suggest that female sex and menopause might be associated with onset of pulmonary MAC of the nodular/bronchiectatic type, and HLA-A26 antigen and diabetes mellitus might be involved in disease exacerbations.
Internal Medicine 01/2010; 49(10):949-53. · 0.97 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background: Nucleic acid testing for the diagnosis of tuberculosis is widely used in Japan. PCR based testing utilizing the COBAS AMPLICOR system is very useful for distinguishing Mycobacterium tuberculosis complex and Mycobacterium avium complex (MAC) with a short tern around time (TAT) of 5.5 hrs. In addition, COBAS AMPLICOR M. avium and M. intracellulare (MAI) kit can distinguish M. avium and M. intracellulare. Recently Roche Diagnostics has developed the COBAS TaqMan MAI assay which demonstrates a very short TAT of 3.5 hrs. In this study, we have evaluated a newly developed rapid sample preparation additive set, i.e.SOL-M,incombination with the TaqMan MAI test.
Methods: We tested 176 clinical materials that pretreated with NALC-NaOH in Ibarakihigasi Hospital from August, 2007, through October, 2007. SOL- M, in combination with the TaqMan MAI test and compared the performance with the current extraction and detection method, i.e. AMPLCOR Mycobacterium Nucleic Acid Extraction set II with COBAS AMPLICOR or TaqMan MAI. To achieve a precise comparison, an aliquot from the NALC treated specimen was used for the each extraction procedure.
Results and Conclusion: Results of clinical materials for Nucleic acid testing are shown Table.
Table:Results of Nucleic acid testing
(Extraction method) COBAS AMPLICORE
(AMPLICORE) COBAS TaqMAN
(AMPLICORE) COBAS TaqMAN
(Inhibition/Nunmber of test) 2.30%
When SOL-M was used, the PCR inhibition rate was significantly lower than that of the current method. Also, SOL-M improved sensitivity when used in combination with TaqMan MAI. Assay time of Nucleic acid testing are shown graphic.
SOL-M further reduced the test TAT to <3hrs. The combination of SOL-M with TaqMan MAI is superior to the COBAS AMPLICOR sample preparation procedure.
Infectious Diseases Society of America 2009 Annual Meeting; 10/2009
[Show abstract][Hide abstract] ABSTRACT: We experienced a case of laboratory cross-contamination of Mycobacterium tuberculosis on the broth based culture system. These false-positive cultures were confirmed by analysis of DNA fingerprinting, RFLP method, which showed the same pattern in three specimens with that of the first manipulated specimen in our laboratory on that day, out of 7 specimens examed. We found possible several process causing cross-contamination where mixture of the foreign body could occur in buffer or NALC-NaOH. False-positive cultures for Mycobacterium tuberculosis may lead to unnecessary, potentially toxic, costly treatment, and changing the treatment strategy. So we must critically interpret a single positive culture, especially by liquid media.