Nontuberculous mycobacteria: susceptibility pattern and prevalence rate in Shanghai from 2005 to 2008.
BACKGROUND
An increasing incidence of disease caused by nontuberculous mycobacteria (NTM) is being reported. The purpose of this study was to determine the isolation rates of NTM from various clinical specimens, and their antimicrobial susceptibility patterns, over a 4-year period in Shanghai.


METHODS
All NTM isolated between 2005 and 2008 at Shanghai Pulmonary Hospital, a key laboratory of mycobacteria tuberculosis in Shanghai, China, were identified with conventional biochemical tests and 16S rRNA gene sequencing. Antimicrobial susceptibility for all NTM was determined using the BACTEC MGIT 960 system.


RESULTS
A total of 21,221 specimens were cultured, of which 4868 (22.94%) grew acid fast bacilli (AFB), and 248 (5.09%) of the AFB were NTM. The prevalence rate of NTM was determined as 4.26%, 4.70%, 4.96% and 6.38% among mycobacteria culture positive samples in years 2005, 2006, 2007 and 2008 respectively. These data indicated that the prevalence rate has continuously increased. Sixteen different species of NTM were identified, the most commonly encountered NTM in Shanghai were M. chelonae (26.7%), followed by M. fortuitum (15.4%), M. kansasii (14.2%), M. avium-intracellulare complex (13.1%) and M. terrae (6.9%). The rare species identified were M. marinum, M. gastri, M. triviale, M. ulcerans, M. smegmatis, M. phlci, M. gordonae, M. szulgai, M. simiae, M. scrofulaceum and M. xenopi. The five most commonly identified NTM species showed high drug resistance to general anti-tuberculosis drugs, particularly, M. chelonae and M. fortuitum appear to be multi-drug resistance.


CONCLUSIONS
The prevalence of NTM in Shanghai showed a tendency to increase over the course of the study. The five most commonly isolated NTM species showed high drug resistance to first line anti-tuberculosis drugs.
Wang
Hong-xiu
HX
Key Laboratory of Mycobacteria Tuberculosis, Shanghai Pulmonary Hospital Affiliated to Tongji University, Shanghai 200433, China.
Yue
Jun
J
Han
Min
M
Yang
Jing-hui
JH
Gao
Rong-liang
RL
Jing
Ling-jie
LJ
Yang
Shu-sheng
SS
Zhao
Yan-lin
YL
D000995:Antitubercular Agents / Q000494:pharmacology; D002681:China / Q000453:epidemiology; D024881:Drug Resistance, Bacterial; D009161:Mycobacterium / Q000187:drug effects* / Q000502:physiology*; D009164:Mycobacterium Infections / Q000453:epidemiology* / Q000382:microbiology*; D016926:Mycobacterium chelonae / Q000187:drug effects / Q000502:physiology; D019907:Mycobacterium fortuitum / Q000187:drug effects / Q000502:physiology; D019909:Mycobacterium kansasii / Q000187:drug effects / Q000502:physiology; D019910:Mycobacterium marinum / Q000187:drug effects / Q000502:physiology; D019912:Mycobacterium xenopi / Q000187:drug effects / Q000502:physiology; D009170:Nontuberculous Mycobacteria / Q000187:drug effects / Q000502:physiology; D015995:Prevalence
D000995:Antitubercular Agents