Molecular epidemiology of tuberculosis in Austria

Molecular fingerprinting of mycobacterium tuberculosis isolates obtained in havana, cuba, by IS6110 restriction fragment length polymorphism analysis and by the double-repetitive-element PCR method

Mycobacterium tuberculosis sputum isolates from 38 patients, obtained in the first 6 months of 1997 in Havana, Cuba, were characterized by IS6110 restriction fragment length polymorphism (RFLP) analysis and the double-repetitive-element PCR (DRE-PCR) method. Among 41 strains from 38 patients, 24 and 25 unique patterns, and 5 and 4 cluster patterns, were found by the RFLP and DRE-PCR methods, respectively. Patients within two of these clusters were found to be epidemiologically related, while no relation was observed in patients in the other clusters. The DRE-PCR method is rapid, and it was as discriminating as IS6110 RFLP analysis in identifying an epidemiological association. Its simplicity makes the technique accessible for subtyping of M. tuberculosis strains in laboratories not equipped to perform RFLP analysis.

The changing face of the epidemiology of tuberculosis due to molecular strain typing--a review

About one third of the world population is infected with tubercle bacilli, causing eight million new cases of tuberculosis (TB) and three million deaths each year. After years of lack of interest in the disease, World Health Organization recently declared TB a global emergency and it is clear that there is need for more efficient national TB programs and newly defined research priorities. A more complete epidemiology of tuberculosis will lead to a better identification of index cases and to a more efficient treatment of the disease. Recently, new molecular tools became available for the identification of strains of Mycobacterium tuberculosis (M. tuberculosis), allowing a better recognition of transmission routes of defined strains. Both a standardized restriction-fragment-length-polymorphism-based methodology for epidemiological studies on a large scale and deoxyribonucleic acids (DNA) amplification-based methods that allow rapid detection of outbreaks with multidrug-resistant (MDR) strains, often characterized by high mortality rates, have been developed. This review comments on the existing methods of DNA-based recognition of M. tuberculosis strains and their peculiarities. It also summarizes literature data on the application of molecular fingerprinting for detection of outbreaks of M. tuberculosis, for identification of index cases, for study of interaction between TB and infection with the human immuno-deficiency virus, for analysis of the behavior of MDR strains, for a better understanding of risk factors for transmission of TB within communities and for population-based studies of TB transmission within and between countries.

Successful treatment of meningoencephalitis caused by Mycobacterium avium intracellulare in AIDS

A wide variety of pathologies afflicting the CNS is see in patients infected with the human immunodeficiency virus. We report the case of relapsing meningoencephalitis caused by Mycobacterium avium intracellulare (MAI) in a homosexual male with the acquired immunodeficiency syndrome in whom repeated use of polymerase chain reaction was required to detect MAI-specific DNA in the cerebrospinal fluid. Successful responses to early empirical antibiotic combination treatment, including the drugs clarithromycin and rifabutin, were demonstrated by clinical, EEG, and CSF improvement during an 8-month period. To our knowledge, this study presents the first known patient with the acquired immunodeficiency syndrome effectively treated for MAI meningoencephalitis and suggests that modern antimycobacterial combination therapy may improve the poor prognosis of CNS infections with nontuberculous mycobacteria.