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Characterization of Mycobacterium Abscessus Subtypes in Shanghai of China

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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.


CT images of patients infected with M. abscessus (A-type) and M. massiliense (M-type). (A) Thin-walled small cavity in A-type patients’ CT scan, (B) thin-walled big cavity in A-type patients’ CT scan, (C) thick-walled small cavity in A-type patients’ CT scan, (D) tree-in-bud pattern in M-type patients’ CT scan, (E) patchy in M-type patients’ CT scan.
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Figure 4: CT images of patients infected with M. abscessus (A-type) and M. massiliense (M-type). (A) Thin-walled small cavity in A-type patients’ CT scan, (B) thin-walled big cavity in A-type patients’ CT scan, (C) thick-walled small cavity in A-type patients’ CT scan, (D) tree-in-bud pattern in M-type patients’ CT scan, (E) patchy in M-type patients’ CT scan.

Mentions: CT manifestations of patients with A- and M-type bacterial infection are summarized in Table 5. Common CT manifestations observed in A-type patients were bronchiectasis (39/42), cavity of various types (29/42, 17/42, 25/42 and 9/42), and patch shadow (13/42), whereas the CT manifestations in M-type patients were bronchiectasis (8/11), patch shadow (4/11), and tree-in-bud (5/11). Manifestations such as thin-walled small cavity (d < 3 cm) (P = 0.002), thin-walled big cavity (d ≥ 3 cm) (P = 0.005), and thick-walled small cavity (d < 3 cm) (P = 0.001) (Figure 4A–C) were more common in A-type patients (Table 6). CT examination further showed that in patients with thin-walled small cavities (d < 3 cm) and patients with thick-walled small cavities, the range of the lesion involving the lung lobe was more extensive. CT manifestations such as tree-in-bud and patch shadow (Figure 4D and E) were more common in M-type patients (P < 0.001, P = 0.012). The incidence rate of overall cavities in A-type patients was significantly higher than that in M-type patients (P < 0.001) (Table 6).


Characterization of Mycobacterium Abscessus Subtypes in Shanghai of China
CT images of patients infected with M. abscessus (A-type) and M. massiliense (M-type). (A) Thin-walled small cavity in A-type patients’ CT scan, (B) thin-walled big cavity in A-type patients’ CT scan, (C) thick-walled small cavity in A-type patients’ CT scan, (D) tree-in-bud pattern in M-type patients’ CT scan, (E) patchy in M-type patients’ CT scan.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 4: CT images of patients infected with M. abscessus (A-type) and M. massiliense (M-type). (A) Thin-walled small cavity in A-type patients’ CT scan, (B) thin-walled big cavity in A-type patients’ CT scan, (C) thick-walled small cavity in A-type patients’ CT scan, (D) tree-in-bud pattern in M-type patients’ CT scan, (E) patchy in M-type patients’ CT scan.
Mentions: CT manifestations of patients with A- and M-type bacterial infection are summarized in Table 5. Common CT manifestations observed in A-type patients were bronchiectasis (39/42), cavity of various types (29/42, 17/42, 25/42 and 9/42), and patch shadow (13/42), whereas the CT manifestations in M-type patients were bronchiectasis (8/11), patch shadow (4/11), and tree-in-bud (5/11). Manifestations such as thin-walled small cavity (d < 3 cm) (P = 0.002), thin-walled big cavity (d ≥ 3 cm) (P = 0.005), and thick-walled small cavity (d < 3 cm) (P = 0.001) (Figure 4A–C) were more common in A-type patients (Table 6). CT examination further showed that in patients with thin-walled small cavities (d < 3 cm) and patients with thick-walled small cavities, the range of the lesion involving the lung lobe was more extensive. CT manifestations such as tree-in-bud and patch shadow (Figure 4D and E) were more common in M-type patients (P < 0.001, P = 0.012). The incidence rate of overall cavities in A-type patients was significantly higher than that in M-type patients (P < 0.001) (Table 6).

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&#8202;M, and 2 B-subtypes. A and M were highly sensitive to tigecycline and amikacin (97.6&ndash;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&#8202;&lt;&#8202;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.