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Characterization of Mycobacterium Abscessus Subtypes in Shanghai of China

View Article: PubMed Central - PubMed

ABSTRACT

The aim of the study was to investigate the epidemic characteristics of Mycobacterium abscessus in Shanghai.

Fifty-five strains from 55 M. abscessus pulmonary disease patients were isolated. Drug sensitivity was measured by a broth microdilution method. Subtypes of M. abscessus were identified by DNA sequencing. Multilocus sequence typing (MLST), mining spanning tree (MST), and pulsed-field gel electrophoresis (PFGE) were used to analyze sequence types (ST) and clonal complexes (CC). Clinical manifestations were assessed by CT imaging.

We identified 42 A isolates, 11 M, and 2 B-subtypes. A and M were highly sensitive to tigecycline and amikacin (97.6–100%). The A-type easily developed drug resistance against clarithromycin. Both types were highly resistance to sulfonamides, moxifloxacin, doxycycline, imipenem, and tobramycin. MLST analysis identified 41 STs including 32 new STs. The MST algorithm distributed 55 isolates into 12 separate CC. The PFGE analysis exhibited 53 distinct restriction patterns and the M-type was closely clustered according to their ST and CC numbers. CT imaging showed that tree-in-bud and patch shadow were commonly observed in M-type, whereas pulmonary cavities were often found in A-type infection patients (P < 0.001).

ST1 in A and ST23 in M-type were the main epidemic strains in Shanghai. The M-type appeared to be prone to epidemic nosocomial transmission.

No MeSH data available.


Phylogenic distribution of clonal complexes (CC) in 55 isolates by mining spanning tree (MST). CC = clonal complexes, MLST = multilocus sequence typing.
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Figure 3: Phylogenic distribution of clonal complexes (CC) in 55 isolates by mining spanning tree (MST). CC = clonal complexes, MLST = multilocus sequence typing.

Mentions: PFGE analysis of 55 isolates showed 53 distinct restriction patterns, with identical patterns being observed between isolates No. 183 and No. 206, and isolates between No. 130 and No. 76 (Figure 2). Clustering strains according to their PFGE patterns showed that 11 M-type strains were clustered as a big complex and 2 B-type strains were placed side by side among A-type strains. Most of the A-type strains were also clustered; however, isolate No. 177 was clustered with the M-type strains (Figure 3). The PFGE pattern clustering also demonstrated that almost all strains with the same ST numbers clustered together, with the exception of 2 strains with ST47 and ST61. With respect to CC, all M-type strains clustered according to their CC classification, whereas A-type strains assigned to CC6, CC7, CC8, and CC9 were distributed in different clusters, suggesting the possibility that A-type strains belonging to these CC are the new epidemic CC.


Characterization of Mycobacterium Abscessus Subtypes in Shanghai of China
Phylogenic distribution of clonal complexes (CC) in 55 isolates by mining spanning tree (MST). CC = clonal complexes, MLST = multilocus sequence typing.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4998240&req=5

Figure 3: Phylogenic distribution of clonal complexes (CC) in 55 isolates by mining spanning tree (MST). CC = clonal complexes, MLST = multilocus sequence typing.
Mentions: PFGE analysis of 55 isolates showed 53 distinct restriction patterns, with identical patterns being observed between isolates No. 183 and No. 206, and isolates between No. 130 and No. 76 (Figure 2). Clustering strains according to their PFGE patterns showed that 11 M-type strains were clustered as a big complex and 2 B-type strains were placed side by side among A-type strains. Most of the A-type strains were also clustered; however, isolate No. 177 was clustered with the M-type strains (Figure 3). The PFGE pattern clustering also demonstrated that almost all strains with the same ST numbers clustered together, with the exception of 2 strains with ST47 and ST61. With respect to CC, all M-type strains clustered according to their CC classification, whereas A-type strains assigned to CC6, CC7, CC8, and CC9 were distributed in different clusters, suggesting the possibility that A-type strains belonging to these CC are the new epidemic CC.

View Article: PubMed Central - PubMed

ABSTRACT

The aim of the study was to investigate the epidemic characteristics of Mycobacterium abscessus in Shanghai.

Fifty-five strains from 55 M. abscessus pulmonary disease patients were isolated. Drug sensitivity was measured by a broth microdilution method. Subtypes of M. abscessus were identified by DNA sequencing. Multilocus sequence typing (MLST), mining spanning tree (MST), and pulsed-field gel electrophoresis (PFGE) were used to analyze sequence types (ST) and clonal complexes (CC). Clinical manifestations were assessed by CT imaging.

We identified 42 A isolates, 11 M, and 2 B-subtypes. A and M were highly sensitive to tigecycline and amikacin (97.6–100%). The A-type easily developed drug resistance against clarithromycin. Both types were highly resistance to sulfonamides, moxifloxacin, doxycycline, imipenem, and tobramycin. MLST analysis identified 41 STs including 32 new STs. The MST algorithm distributed 55 isolates into 12 separate CC. The PFGE analysis exhibited 53 distinct restriction patterns and the M-type was closely clustered according to their ST and CC numbers. CT imaging showed that tree-in-bud and patch shadow were commonly observed in M-type, whereas pulmonary cavities were often found in A-type infection patients (P < 0.001).

ST1 in A and ST23 in M-type were the main epidemic strains in Shanghai. The M-type appeared to be prone to epidemic nosocomial transmission.

No MeSH data available.