Survival of tubercle bacilli in heat-fixed and stained sputum smears.
We used a slide culture technique to detect tubercle bacilli surviving in sputum smears (n=46) after conventional heat fixation and Ziehl-Neelsen staining. In all heat-fixed sputum smears, tubercle bacilli survived after time 0 (n=22), 24 h (n=7), 48 h (n=7), 72 h (n=4), and seven days (n=6). None of the stained sputum smears showed growth on slide cultures. Viable tubercle bacilli remaining in heat-fixed sputum smears for at least seven days may present an infection risk to laboratory staff. Thus, sputum smears should be stained immediately by the Ziehl-Neelsen method or stored in a safe container to avoid transmission of tuberculosis.
Cardoso
C L
CL
Laboratório de Microbiologia, Departamento de Análises Clínicas, Universidade Estadual de Maringá, Maringá, PR, 87020-900, Brasil.
Giacomelli
L R
LR
Helbel
C
C
Sant'Ana
J J
JJ
Martins
F M
FM
Barreto
A M
AM
D004396:Coloring Agents; D006358:Hot Temperature; D006801:Humans; D009170:Nontuberculous Mycobacteria / Q000254:growth & development*; D013183:Sputum / Q000382:microbiology*; D013997:Time Factors
D004396:Coloring Agents