Mycobacterium tuberculosisL-forms

Abstract

M. tuberculosis L-forms researches done in China during the recent years were reviewed in this article. M. tuberculosis L-forms could be produced spontaneously or induced by isoniazid or D-cyclic serine, that influenced the synthesis of cell walls. Among the acid-fast organisms isolated from the patients, more L-forms were found than vegetative forms. In extrapulmonary tuberculosis, M. tuberculosis disseminated through the blood mainly in L-forms, L-forms could adhere on the surface or harbor inside the red cells. With the loss of cell walls, L-forms of M. tuberculosis lost some of their pathogenic features, specific for diagnosis, e.g. OT reaction remained negative and no tuberculosis tubercles formed. In most of these patients only interstitial inflammation could be seen in different organs, similar to that of virus or mycoplasma infection. Unless acid-fast, immunohistochemical staining or isolation was made, it often led to misdiagnosis in histological examination. According to clinical examinations and animal experiments, M. tuberculosis L-forms were found to be closely related to pulmonary carcinoma, especially in adenocarcinoma L-forms were isolated in 34.38% of the cases. M. tuberculosis L-forms were low in pathogenicity, the diseases caused were often escaped from being noticed. M. tuberculosis L-forms were found in 86% of abnormal feeling in nasopharynx, in 32% of chronic prostatitis. M. tuberculosis L-forms were also found in semen of infertile male, the adhesion of L-forms on the sperms inhibited their motility. M. tuberculosis L-forms grew better and faster in liquid than on solid media. The most sensitive method of detection was the using of immunohistochemical technique. In acid-fast staining IK method was better than ZN method. In compensation to the loss of cell walls, the cell membranes became greatly thickened, that increased the difficulty in DNA extraction for PCR examination. Physical grinding could be used to increase the positive rate in detection. M. tuberculosis vegetative forms as well as L-forms proved to be equally important in recognition and elimination of M. tuberculosis . Further study in L-forms of M. tuberculosis is necessary for controlling tuberculosis. Keywords: M. tuberculosis , L-forms, biological characters, pathogenicity.