Recovery of mycobacteria from patients with cystic fibrosis.
Despite decontamination, overgrowth by pseudomonads renders cultural isolation of mycobacteria from respiratory specimens of patients with cystic fibrosis (CF) difficult or impossible. We performed a prospective study by comparing levels of reduction of overgrowth and recovery of mycobacteria using either pretreatment with N-acetyl-L-cysteine (NALC)-NaOH alone or pretreatment with NALC-NaOH and then with oxalic acid. From 406 specimens of 148 CF patients, 11 specimens were positive for mycobacteria, 5 of which grew mycobacteria after decontamination by either procedure. Three specimens grew mycobacteria only after decontamination with NALC-NaOH, whereas three specimens grew mycobacteria only after treatment with NALC-NaOH followed by oxalic acid but were overgrown after decontamination with NALC-NaOH. Thus, inactivation of mycobacteria by the more aggressive oxalic acid treatment offsets its beneficial effect of reducing the proportion of cultures overgrown with microorganisms other than mycobacteria.
Bange
F C
FC
Institute of Medical Microbiology, Medical School Hannover, 30625 Hannover, Germany. bange@mikrobio.mh-hannover.de
Kirschner
P
P
Böttger
E C
EC
D000111:Acetylcysteine; D000293:Adolescent; D000328:Adult; D001431:Bacteriological Techniques; D003550:Cystic Fibrosis / Q000382:microbiology*; D005260:Female; D006801:Humans; D008297:Male; D009161:Mycobacterium / Q000254:growth & development / Q000302:isolation & purification*; D019815:Oxalic Acid; D011446:Prospective Studies; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification; D012137:Respiratory System / Q000382:microbiology; D012972:Sodium Hydroxide
D012972:Sodium Hydroxide; D019815:Oxalic Acid; D000111:Acetylcysteine