Phosphate buffered saline for transport of M. tuberculosis cultures.

Azger, D.; Radhakrishnan, R.; Nagarajan, P.; Ponnuraja, C.; Kumar, V.; Selvakumar, N.

Indian Journal of Applied Microbiology; 2015; 18; 1-4.       

Abstract: The accuracy of the anti-tuberculosis drug susceptibility testing (DST) methods in different mycobacteriology laboratories requires transportation of M. tuberculosis cultures from Supranational Reference Laboratory to Regional / Intermediate Reference laboratories to assess the proficiency testing of M. tuberculosis. This study reveals the use of PBS for the transportation of M. tuberculosis and describes the robustness and reliability of PBS for transfer of M. tuberculosis cultures across the laboratories. Of the 16 panel sets, each with 20 culture suspensions prepared in phosphate buffered saline (PBS) and transported to 15 Intermediate Reference Laboratories and one National Reference laboratory for panel testing of drug susceptibility testing (DST), 288 (288/300= 96%) cultures were retrieved (results from one IRL was not available). The reproducibility (as shown in parenthesis) of susceptibility pattern for Isoniazid (97%) Rifampicin (85%) Ethambutol (90%), Streptomycin (88%), Kanamycin (98%) and Ofloxacin (95%) from IRLs revealed the sustainability of phenotypic characters of the panel cultures suspended in PBS. It implicates the easiness and reliability for transportation of Mycobacterium tuberculosis cultures in PBS across the tuberculosis laboratory network.