Synthesis of new sugar derivatives and evaluation of their antibacterial activities against Mycobacterium tuberculosis.

A series of sugar derivatives (1-13) were synthesized and evaluated for antibacterial activity against Mycobacteriumtuberculosis (MTB), especially multi-drug resistant (MDR) MTB, and the structure-activity relationships of these compounds were studied. The results showed that the compound OCT313 (2-acetamido-2deoxy-beta-D-glucopyranosyl N,N-dimethyldithiocarbamate) (4) exhibited significant in vitro bactericidal activity, and that the dithiocarbamate group at C-1 position of the glucopyranoside ring was requisite for the antibacterial activity.

[Identification of 23 mycobacterial species by Invader assay with targeting 16S rRNA gene and ITS-1 region--comparison with DDH method in clinical isolates].

Purpose And Method: The Invader assay was developed to identify 23 mycobacterial species using probes derived from the species-specific region of the 16S rRNA gene and the 16S-23S rRNA internal transcribed spacer 1 (ITS-1) region, with minor modifications of our previous study. In the present study, we compared the identification capability between the Invader assay and DNA-DNA hybridization (DDH) method. DDH is commonly used to identify non-tuberculosis mycobacterium in Japan and 636 clinical mycobacterial strains cultured on Ogawa slants were tested.

Biological and molecular characteristics of Mycobacterium tuberculosis clinical isolates with low-level resistance to isoniazid in Japan.

We reevaluated the BACTEC MGIT 960 antimicrobial susceptibility testing system (MGIT 960 AST) by using 1,112 isolates of Mycobacterium tuberculosis. When the results of MGIT 960 AST were compared with that of the proportion method using Ogawa medium (Ogawa PM), discrepant results were obtained for 30 strains with isoniazid, all resistant by MGIT 960 AST but susceptible by Ogawa PM. For 93% of the strains that produced discrepant results, the MIC was 0.

[Comparative study of bactec MGIT 960 AST and conventional proportion method using Ogawa medium for the drug susceptibility testing of Mycobacterium tuberculosis to isoniazid].

Objective: To evaluate the accuracy of drug susceptibility testing to isoniazid with BACTEC MGIT 960 (MGIT AST) comparing with the standard proportion method using Ogawa medium.

Method: A total of 1109 M. tuberculosis strains, which were selected from the collection of RYOKEN drug resistance survey in 2002, were selected and subjected to the susceptibility testing to isoniazid using MGIT AST and 1% Ogawa standard methods.

Evaluation of major membrane protein-II as a tool for serodiagnosis of leprosy.

As serodiagnosis is the easiest way of diagnosing a disease, the utility of Mycobacterium leprae-derived major membrane protein-II (MMP-II), one of the immuno-dominant antigens, in the serodiagnosis of leprosy was examined. The percent positivity by an enzyme-linked immunosorbent assay for anti-MMP-II antibody was 82.4% for multi-bacillary leprosy, and the specificity of the test was 90.

Synthesis of new sugar derivatives from Stachys sieboldi Miq and antibacterial evaluation against Mycobacterium tuberculosis, Mycobacterium avium, and Staphylococcus aureus.

A series of sugar derivatives (7-14) were synthesized from stachyose, a sugar compound of Stachys sieboldi Miq, and evaluated for antibacterial activity against Mycobacterium tuberculosis, Mycobacterium avium, and Staphylococcus aureus, and their structure-activity relationships were studied. The results showed that the compound OCT359 (allyl O-(2,3,4,6-tetra-O-acetyl-alpha-D-galactopyranosyl)-(1-->6)-O-(2,3,4-tri-O-acetyl-alpha-D-galactopyranosyl)-(1-->6)-O-2,3,4-tri-O-acetyl-beta-D-glucopyranoside) (12) exhibited in vitro antibacterial activity. The allyl group at C-1 and the acetoxy groups of the manninotrioside were requisite for the antibacterial activity.

[BACTEC MGIT 960 system for drug susceptibility testing of Mycobacterium tuberculosis: a study using external quality assessment strains].

Objective: To evaluate the performance of the BACTEC MGIT 960 system for drug susceptibility testing (MGIT AST) of Mycobacterium tuberculosis to isoniazid, rifampin, streptomycin and ethambutol.

Design: Fifty external quality assessment strains of M. tuberculosis provided by the Coordinating Centers of WHO/ IUATLD were tested by BACTEC MGIT 960 system, and the results were compared with the referee results of the WHO/IUATLD Supranational Reference Laboratory Network (SRLN).

Simple fibroblast-based assay to test the pyrazinamide susceptibility of Mycobacterium tuberculosis.

A simple fibroblast-based assay (SFA) was found to be efficient in evaluating the susceptibilities of clinical isolates of Mycobacterium tuberculosis to pyrazinamide (PZA). Forty-five clinical isolates were examined. The MICs of PZA for susceptible strains in an SFA were between 3.

Mutations including IS6110 insertion in the gene encoding the MPB64 protein of Capilia TB-negative Mycobacterium tuberculosis isolates.

A simple immunochromatographic assay, Capilia TB, using anti-MPB64 monoclonal antibodies, is a kit for discriminating between the Mycobacterium tuberculosis complex and mycobacteria other than tubercle bacilli. The sensitivity of the kit was estimated to be 99.2% (381 of 384 samples).

[Standardization of laboratory tests for tuberculosis and their proficiency testing].

Explanations of proper collection procedures are imperative for accurate laboratory analysis. The quality of specimens collected and the proper transport of those specimens to the laboratory are critical to successful isolation of etiological agents. Most mycobacteria grow at a relatively slow rate.

Heterogeneity of RNA polymerase gene (rpoB) sequences of Mycobacterium gordonae clinical isolates identified with a DNA probe kit and by conventional methods.

In a previous study, we have evaluated genetic identification by using the rpoB gene, which was recently introduced by Kim et al. (J. Clin.

Evaluation of BACTEC MGIT 960 PZA medium for susceptibility testing of Mycobacterium tuberculosis to pyrazinamide (PZA): compared with the results of pyrazinamidase assay and Kyokuto PZA test.

The fully automated BACTEC MGIT 960 PZA medium for susceptibility testing of Mycobacterium tuberculosis to pyrazinamide (PZA) was evaluated using 101 Mycobacterium tuberculosis clinical isolates. The results obtained with the system were compared with those of the pyrazinamidase (PZase) assay and the Kyokuto PZA test based on a broth culture, which is commercially available in Japan. The overall concordance rate was 90.

Simple fibroblast-based assay for screening of new antimicrobial drugs against Mycobacterium tuberculosis.

In this study, we propose a simple and reproducible host-cell-based assay for the screening of antimycobacterial drugs that is suitable for drug discovery. The method evaluates both antimycobacterial activity of the drugs and their cytotoxicity to host cells. The basis of this simple fibroblast-based assay (SFA) is that cells of human lung fibroblast cell line MRC-5, which are highly sensitive to mycobacterial cytotoxicity, are killed by virulent Mycobacterium tuberculosis strain H(37)Rv bacilli in response to the viability of bacilli.

rpoB genotypes of Mycobacterium tuberculosis Beijing family isolates from East Asian countries.

The 81-bp region of the rpoB gene in 66 Rif(r) Mycobacterium tuberculosis isolates from China, Japan, Korea, and Taiwan was analyzed. Twelve single-nucleotide substitutions in the rpoB gene were detected. The most prevalent mutations were at Ser-531 (52%), Asp-516 (17%), and His-526 (11%).