Journal of Microbiology

Journal Article

Targeting the rpoB Gene Using Nested PCR-Restriction Fragment Length Polymorphism for Identification of Nontuberculous Mycobacteria in Hospital Tap Water: Ji-Hyun Shin , Hae-Kyung Lee , Eun-Jin Cho , Jae-Yon Yu , Yeon-Ho Kang; J. Microbiol. 2008;46(6):608-614. Published online December 24, 2008; DOI: https://doi.org/10.1007/s12275-008-0102-6

Abstract: Nontuberculous mycobacteria (NTM) are ubiquitous in the environment and can cause nosocomial infections in immunocompromised patients. Recently the presence of NTM in public drinking water and hospital water distribution systems has been reported. Their ability to form biofilms and their resistance to chlorine both contribute to their survival and colonization in water distribution systems. Here we analyzed thirty-two hospital tap water samples that were collected from different locations in three hospitals so as to evaluate the prevalence of NTM species. The water samples were concentrated by membrane filtration and then eluted with sterilized water following sonication. Two-step direct PCR targeting the rpoB gene, restriction fragment length polymorphism (RFLP) using the MspI restriction enzyme, and sequence analysis were performed for identification of NTM to the species level. The sequences of each PCR product were analyzed using BLASTN. Seven samples (7/32, 21.9%) were positive for NTM as determined by nested-PCR. The PCR-RFLP results indicated five different patterns among the seven positive PCR samples. The waterborn NTM were identified, including M. peregrinum, M. chelonae (2 cases), M. abscessus, M. gordonae (2 cases), and Mycobacterium sp. JLS. The direct two-step PCR-RFLP method targeting the rpoB gene was effective for the detection and the differentiation of NTM species from hospital tap water.

Eveluation of line probe assay in detecting rifampicin resistance of mycobacterium tuberculosis: Park, Young Kil , Cho, Snag Hyun , Na, Nyoung Kuk , Song, Chul Yong , Bai, gill Han , Kim, Sang Jae; J. Microbiol. 1997;35(3):177-180.

Abstract: The purpose of this study was to evaluate the efficiency of Line Probe Assay (LiPA) in detecting the rpoB gene mutation of clinically isolated Mycobacterium tuberculosis (MTB) and to compare the level of resistance to the various rifamycins with their mutation sites. The mutation in the rpoB gene was found in 84 (97.6%) out of 86 rifampicin (RMP) resistant strains as determined by LiPA. No mutation was observed in 2 RMP resistant strains and in any of 38 RMP susceptible strains tested. Only one of 3 strains with Δ5/R5, one of 2 strains with Δ3, and one of 3 strains with Δ2/R2 LiPA profile showed a slightly lower level of resistance to the rifapentine than the other strains. Although we could not find correlations between mutation sites in the rpoB gene and the level of susceptibility to the various rifamycins, the LiPA is recommended as a fast screening tool for detection of RMP resistant MTB.

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