Sputum Mycobacterial Culture Procedures

Each sputum sample should contain 5–10 ml of sputum. Direct smear, prepared with sputum, was stained using auramine and then examined by light-emitting diode (LED) microscopy (Carl Zeiss AG, PrimoStar, Germany). The solid culture with LJ medium was performed following the guidelines from the Chinese anti-TB Association (13 ) and the MGIT960 culture was conducted according to the manufacturer's protocol. Briefly, after liquefied and decontaminated by the hydroxide-sodium citrate-N-actyl-L-cysteine method, 0.5 ml of sputum sediment was inoculated onto an LJ slant and incubated at 37°C for up to 8 weeks in an incubator, and/or inoculated 0.5 ml into a 7-ml MGIT tube and incubated in the BACTEC MGIT 960 system (BD Diagnostic Systems, Sparks, MD, USA). Positive cultures of MGIT960 were confirmed by examining Ziehl-Neelsen (ZN)-stained smears for AFB.