Prevalence and Species Spectrum of Pulmonary Nontuberculous Mycobacteria Isolates at a Tertiary Care Center

영선 주1   나은 곽2   건한 김3   은정 윤*4   석훈 정4   

1 Department of Clnical Pathology, Sangji University College of Science, Wonju
2 BioPark Diagnostics Inc.,
3 Department of Laboratory Medicine, Gangnam Severance Hospital,
4 epartment of Laboratory Medicine and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul

Abstract

Background: Pulmonary infection with nontuberculous mycobacteria (NTM) is increasing in South Korea. Since treatment strategy differs by NTM species, accurate identification is necessary. In this study, using Mycobacterium pulmonary isolates recently recovered from a general hospital in Seoul, the prevalence of NTM isolates was investigated.

Methods: A total of 483 Mycobacterium pulmonary strains isolated between May and November 2018 from an 814-bed general hospital in South Korea were analyzed. Bacterial species were identified based on nucleotide sequences of the 16S-23S rDNA internal transcribed spacer and the rpoB gene.

Results: From a total of 1,209 pulmonary specimens from patients suspected to be infected with mycobacteria, 324 deduplicate strains were isolated, comprising 90 Mycobacterium tuberculosis and 229 NTM strains. Among the NTM isolates, 61.5% (n=144) were Mycobacterium avium complex (MAC), including 92 M. avium and 52 Mycobacterium intracellulare, while 8.1% (n=19) represented Mycobacterium abscessus, including 10 M. abscessus subsp. abscessus and 9 M. abscessus subsp. massiliense. In addition, 12 (5.1%) Mycobacterium lentiflavum, 12 (5.1%) Mycobacterium gordonae, 6 (2.6%) Mycobacterium kansasii, and 5 (2.1%) Mycobacterium fortuitum were identified. In addition, Mycobacterium mucogenicum (n=2), Mycobacterium septicum (n=1), Mycobacterium colombiens (n=1), Mycobacterium asiaticum (n=1), and Mycobacterium celatum (n=1) were identified.

Conclusion: Among the recently recovered Mycobacterium pulmonary strains, more than half were identified as NTM, and MAC was the most prevalent NTM, followed by M. abcessuss. (Ann Clin Microbiol 2019;22:71-76)

Keywords

Non-tuberculosis mycobacteria   Pulmonary specimen   Species identification   


Figures & Tables

Table 1. Primers used in the study

PrimerSequence (5’-3’)Target geneLocationTm (°C)
ITS-F_rrs-1395-1415CCCGTCACGTCATGAAAGTCrrs1395-141560.5
ITS-R_rrl-81-62GAGGCWTATCGCAGCCTCCrrl81-6261.6
rpoB_MABS_F2728-2748GACATCATCCTGAACACCCACrpoB2728-274861.3
rpoB_MABS_R3078-3056CAGCTTCAGGATGTACATGTAACrpoB3078-305661.1