title: Bronchoscopic microsampling for bacterial colony counting in relevant lesions in patients with pulmonary Mycobacterium avium complex infection.
abstract: OBJECTIVE
  The incidence of pulmonary Mycobacterium avium complex (MAC) infections with nodular/bronchiectasis lesions is increasing. However, factors determining deterioration are unknown. In the present study, we investigated quantitative MAC cultures obtained through bronchoscopic microsampling (BMS) from patients with pulmonary MAC infection and analyzed the relationship between MAC culture and the short-term natural history. We also assessed chest computed tomography (CT) findings for the deteriorating factors.
  
  
  METHODS
  For this prospective study, MAC was collected from peripheral lung lesions by BMS through endobronchial ultrasonography. MAC colonies were counted on Middlebrook 7H11 agar. We compared the number of MAC colonies with laboratory data and chest CT findings.
  
  
  METHODS
  We studied 26 patients with pulmonary MAC infection.
  
  
  RESULTS
  The patients were divided into 2 groups: 11 patients in the non-deteriorated group and 15 patients in the deteriorated group. The number of MAC colonies was significantly correlated with deterioration of MAC infection (p < 0.001). In the non-deteriorated group, chest CT scans showed nodular/bronchiectasis lesions in 8 patients (73%) and consolidated lesions in 3 patients (27%). In the deteriorated group, chest CT scans showed nodular/bronchiectasis lesions in 1 patient (7%), consolidated lesions in 6 patients (40%), and cavitary lesions in 8 patients (53%).
  
  
  CONCLUSIONS
  The number of MAC colonies in relevant lesions investigated by BMS was significantly larger in the deteriorated group than in the non-deteriorated group. Cavitary and consolidated lesions observed from chest CT scans are thought to indicate a high risk of progression of pulmonary MAC infection.
authors.affiliation: The First Department of Internal Medicine, Shinshu University School of Medicine, Japan.
authors.forename: Atsuhito
authors.initials: A
authors.lastname: Ushiki
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Yamazaki
authors.forename: Sekiya
authors.initials: S
authors.lastname: Koyama
authors.forename: Kenji
authors.initials: K
authors.lastname: Tsushima
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Masayuki
authors.initials: M
authors.lastname: Hanaoka
authors.forename: Keishi
authors.initials: K
authors.lastname: Kubo
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D058491:Bacterial Load / Q000379:methods*; D001999:Bronchoscopy / Q000379:methods*; D018450:Disease Progression; D005260:Female; D006801:Humans; D008171:Lung Diseases / Q000000981:diagnostic imaging / Q000382:microbiology*; D008297:Male; D008875:Middle Aged; D015269:Mycobacterium avium Complex / Q000302:isolation & purification*; D015270:Mycobacterium avium-intracellulare Infection / Q000000981:diagnostic imaging / Q000382:microbiology*; D011446:Prospective Studies; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography