title: Effect of transportation and acid neutralization on recovery of mycobacteria from processed specimens.
abstract: Because of the increasing incidence of tuberculosis, more rapid detection of mycobacteria has become an important issue. Realizing that not every clinical laboratory has a rapid detection system for growing mycobacteria, this study was conducted to examine the feasibility of submitting sediments of processed specimens to a reference laboratory for further testing in a radiometric system. Using N-acetyl-L-cysteine-NaOH solution, 247 respiratory specimens were processed at a diagnostic laboratory. Half of each sediment was cultured on conventional media. The remainder was kept at 4 degrees C for a period of up to 1 week before transportation to a reference laboratory for culture by BACTEC system. Both laboratories recovered 25 organisms: 15 as Mycobacterium tuberculosis (MT) and 10 as M avium complex (MAC). Additionally, mycobacteria (MT[3], MAC[6], M gordonae [4], and M fortuitum [1]) were recovered from 14 specimens by the diagnostic laboratory that were not grown by the reference laboratory. These results indicate a significant decrease in viability of mycobacteria after processing of the specimens. Acid neutralization of the digested respiratory sediments significantly improved the recovery rate of mycobacteria even after 2 days of delay in culture. This preliminary work suggests that more extensive studies will provide useful information to delineate approaches to submitting neutralized sediments for mycobacterial cultures.
authors.affiliation: Texas Department of Health, Austin 78756, USA.
authors.forename: F K
authors.initials: FK
authors.lastname: Babakhani
authors.forename: N G
authors.initials: NG
authors.lastname: Warren
authors.forename: D P
authors.initials: DP
authors.lastname: Henderson
authors.forename: H P
authors.initials: HP
authors.lastname: Dalton
mesh_terms: D006801:Humans; D006863:Hydrogen-Ion Concentration; D008828:Microbiological Techniques / Q000592:standards*; D015269:Mycobacterium avium Complex / Q000302:isolation & purification; D015270:Mycobacterium avium-intracellulare Infection / Q000175:diagnosis; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D013048:Specimen Handling / Q000592:standards*; D013183:Sputum / Q000382:microbiology; D013997:Time Factors; D014376:Tuberculosis / Q000175:diagnosis