title: Comparison of Mycobacterial Growth Indicator Tube with Culture on RGM Selective Agar for Detection of Mycobacteria in Sputum Samples from Patients with Cystic Fibrosis.
abstract: Nontuberculous mycobacteria (NTM) are an important cause of pulmonary disease in patients with cystic fibrosis (CF). A new culture medium (RGM medium) for the isolation of rapidly growing mycobacteria from the sputum of cystic fibrosis patients has recently been reported. The aim of this study was to compare culture of sputum samples on RGM medium with culture using a standard automated liquid culture method. Sputum samples were obtained from 187 distinct patients with CF attending King's College Hospital, London, United Kingdom. Each sample was decontaminated with 3% oxalic acid and inoculated into a mycobacterial growth indicator tube (MGIT) that was monitored for 42 days using the Bactec MGIT 960 instrument. Each sample was also cultured, without decontamination, onto RGM medium, which was incubated for 10 days at 30°C. Mycobacteria were isolated from 28 patients (prevalence, 15%). Mycobacteria were detected in 24 samples (86%) using the MGIT and in 23 samples (82%) using RGM medium (P = 1.00). In this setting, RGM medium showed sensitivity equivalent to that of the MGIT for isolation of NTM from the sputum of patients with CF. RGM medium offers a simple, convenient tool that can be embedded into routine culture methods, allowing the culture of all sputum samples that are submitted from patients with CF.
authors.affiliation: Microbiology Department, King's College Hospital NHS Foundation Trust, London, United Kingdom.
authors.forename: Ian
authors.initials: I
authors.lastname: Eltringham
authors.affiliation: Microbiology Department, Bedford Hospital, Bedford, United Kingdom.
authors.forename: Julie
authors.initials: J
authors.lastname: Pickering
authors.affiliation: Microbiology Department, Bedford Hospital, Bedford, United Kingdom.
authors.forename: Helen
authors.initials: H
authors.lastname: Gough
authors.affiliation: Microbiology Department, Freeman Hospital, Newcastle upon Tyne, United Kingdom Department of Applied Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom.
authors.forename: Clair L
authors.initials: CL
authors.lastname: Preece
authors.affiliation: Microbiology Department, Freeman Hospital, Newcastle upon Tyne, United Kingdom Department of Applied Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom john.perry@nuth.nhs.uk.
authors.forename: John D
authors.initials: JD
authors.lastname: Perry
mesh_terms: D000293:Adolescent; D000328:Adult; D001431:Bacteriological Techniques / Q000379:methods*; D002648:Child; D003470:Culture Media / Q000737:chemistry*; D003550:Cystic Fibrosis / Q000150:complications*; D005260:Female; D006761:Hospitals; D006801:Humans; D008131:London; D008297:Male; D008875:Middle Aged; D009165:Mycobacterium Infections, Nontuberculous / Q000175:diagnosis*; D009170:Nontuberculous Mycobacteria / Q000302:isolation & purification*; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013048:Specimen Handling / Q000379:methods; D013183:Sputum / Q000382:microbiology*; D013696:Temperature; D055815:Young Adult
chemical_list: D003470:Culture Media