Until now it was thought that M. tuberculosis bacteria in the lungs of TB patients were rapidly multiplying. However recent research by Simon Waddell and colleagues from St George's University of London and the University of Leicester revealed the tuberculosis bacteria in the sputum of TB patients resemble bacteria that are growing very slowly or hardly at all.
Waddell said that has caused concern, since slowly growing bacteria are non-responsive to treatment with isoniazid, one of the main antibiotics used to treat TB. The researchers said their findings might explain why it takes six months to treat pulmonary TB, while most bacterial infections are treated in days.
Waddell presented the study Monday in Harrogate, England, during a meeting of the Society for General Microbiology.