title: Cord formation in BACTEC(TM) medium aids rapid identification of Mycobacterium tuberculosis complex.
abstract: Mycobacterium tuberculosis complex (MTC) organisms form serpentine cords in fluid culture medium. Reporting of a presumptive identification of MTC based on cording allows rapid identification of patients with tuberculosis. A total of 612 positive mycobacterial cultures from 316 patients over 3 years (2008-2010) were evaluated for the presence of cord formation. Cording was identified in 426 (69.6%) specimens, while the reference laboratory confirmed M. tuberculosis in 424 specimens (69.3%). Sensitivity of the test in our laboratory was 99.1% (95%CI 97.4-99.7) and specificity was 96.8% (95%CI 92.8-98.7). Presumptive identification of M. tuberculosis by the presence of cording formation is both sensitive and specific.
authors.affiliation: Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK.
authors.forename: G A
authors.initials: GA
authors.lastname: O'Hara
authors.affiliation: Department of Medical Microbiology, Barnet and Chase Farm NHS Trust, London, UK.
authors.forename: S
authors.initials: S
authors.lastname: Abdullah
authors.affiliation: Department of Respiratory Medicine, Barnet and Chase Farm NHS Trust, London, UK.
authors.forename: D D
authors.initials: DD
authors.lastname: Creer
authors.affiliation: Department of Medical Microbiology, Barnet and Chase Farm NHS Trust, London, UK.
authors.forename: A F
authors.initials: AF
authors.lastname: Elsaghier
mesh_terms: D001431:Bacteriological Techniques; D003470:Culture Media; D005240:Feasibility Studies; D006801:Humans; D009169:Mycobacterium tuberculosis / Q000254:growth & development / Q000302:isolation & purification*; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013997:Time Factors; D014376:Tuberculosis / Q000175:diagnosis* / Q000382:microbiology
chemical_list: D003470:Culture Media