[Study on pathogenicity of sputum from cavity of sputum negative patients with pulmonary tuberculosis after short course chemotherapy].
OBJECTIVE
To find out whether or not the sputa of pulmonary tuberculosis(PTB) patients with cavitation but sputum negative have pathogenicity after short course chemotherapy.


METHODS
Guinea pigs were inoculated with sputa of PTB patients who were with cavitation but sputum negative after having finished short course chemotherapy. Then their body weight, enlargement of local lymph nodes and other ordinary symptom were observed. Six weeks later, pathological changes of TB in the internal organs were examined by dissecting these guinea pigs. Culture and drug resistance test of tubercle bacillus were also conducted. All of which were with negative and positive controls.


RESULTS
Of the 63 cases included, 3(5%) patients' sputa resulted in tuberculous nodulation varying in amount in lung, liver and spleen of these guinea pigs, and the culture for tubercle bacillus of these sputa was positive too.


CONCLUSIONS
5% of sputum collected from PTB patients with cavitation but sputum negative still show pathogenicity after short course chemotherapy. For the cases with drug-resistant PTB and slow sputum negative conversion, the treatment should be prolonged and tubercle bacilli in their sputa should be monitored.
Feng
H
H
Tianjin Lung Hospital, Tianjin 300222, China.
Du
B
B
Dong
Z
Z
D000818:Animals; D015169:Colony Count, Microbial; D004195:Disease Models, Animal; D024881:Drug Resistance, Bacterial / Q000502:physiology; D004358:Drug Therapy; D006168:Guinea Pigs; D006801:Humans; D007740:L Forms / Q000187:drug effects / Q000472:pathogenicity*; D008099:Liver / Q000382:microbiology; D008168:Lung / Q000382:microbiology; D009169:Mycobacterium tuberculosis / Q000187:drug effects / Q000472:pathogenicity*; D013154:Spleen / Q000382:microbiology; D013183:Sputum / Q000382:microbiology*; D014397:Tuberculosis, Pulmonary / Q000188:drug therapy / Q000382:microbiology*