Multidrug-Resistant Mycobacterium tuberculosis

About: Multidrug-Resistant Mycobacterium tuberculosis is a research topic. Over the lifetime, 333 publications have been published within this topic receiving 15977 citations.

Simultaneous detection and strain differentiation of Mycobacterium tuberculosis for diagnosis and epidemiology.

Abstract: Widespread use of DNA restriction fragment length polymorphism (RFLP) to differentiate strains of Mycobacterium tuberculosis to monitor the transmission of tuberculosis has been hampered by the need to culture this slow-growing organism and by the level of technical sophistication needed for RFLP typing. We have developed a simple method which allows simultaneous detection and typing of M. tuberculosis in clinical specimens and reduces the time between suspicion of the disease and typing from 1 or several months to 1 or 3 days. The method is based on polymorphism of the chromosomal DR locus, which contains a variable number of short direct repeats interspersed with nonrepetitive spacers. The method is referred to as spacer oligotyping or "spoligotyping" because it is based on strain-dependent hybridization patterns of in vitro-amplified DNA with multiple spacer oligonucleotides. Most of the clinical isolates tested showed unique hybridization patterns, whereas outbreak strains shared the same spoligotype. The types obtained from direct examination of clinical samples were identical to those obtained by using DNA from cultured M. tuberculosis. This novel preliminary study shows that the novel method may be a useful tool for rapid disclosure of linked outbreak cases in a community, in hospitals, or in other institutions and for monitoring of transmission of multidrug-resistant M. tuberculosis. Unexpectedly, spoligotyping was found to differentiate M. bovis from M. tuberculosis, a distinction which is often difficult to make by traditional methods.

Strain identification of Mycobacterium tuberculosis by DNA fingerprinting: recommendations for a standardized methodology.

Abstract: DNA fingerprinting of Mycobacterium tuberculosis has been shown to be a powerful epidemiologic tool. We propose a standardized technique which exploits variability in both the number and genomic position of IS6110 to generate strain-specific patterns. General use of this technique will permit comparison of results between different laboratories. Such comparisons will facilitate investigations into the international transmission of tuberculosis and may identify specific strains with unique properties such as high infectivity, virulence, or drug resistance.

Nosocomial transmission of multidrug-resistant Mycobacterium tuberculosis. A risk to patients and health care workers.

Abstract: Objective To determine the factors associated with the development of multidrug-resistant tuberculosis among patients at a New York City Hospital and to investigate possible nosocomial transmission. Design A retrospective case-control study and tuberculin skin test survey. Patients Twenty-three patients with tuberculosis whose isolates were resistant to at least isoniazid and rifampin (case patients) were compared with patients with tuberculosis whose isolates were susceptible to all agents tested (controls). Tuberculin skin test conversion rates were compared among health care workers assigned to wards where patients with tuberculosis were frequently or rarely admitted. Setting A large, teaching hospital in New York City. Measurements Mycobacterium tuberculosis isolates from case patients and controls were typed by restriction fragment length polymorphism analysis. Results Case patients were younger (median age, 34 compared with 42 years; P = 0.006), more likely to be seropositive for HIV (21 of 23 compared with 11 of 23 patients; odds ratio, 11.5; 95% CI, 1.9 to 117), and more likely to have had a previous hospital admission within 7 months before the onset of tuberculosis (19 of 23 compared with 5 of 23 patients; odds ratio, 17.1; CI, 3.3 to 97), particularly on one ward (12 of 23 compared with 0 of 23 patients; odds ratio, undefined; P = 0.002). Health care workers assigned to wards housing case patients were more likely to have tuberculin skin test conversions than were health care workers assigned to other wards (11 of 32 compared with 1 of 47 health care workers; P less than 0.001). Few (6 of 23) case patients were placed in acid-fast bacilli isolation, and no rooms tested had negative pressure. Of 16 available multidrug-resistant isolates obtained from case patients, 14 had identical banding patterns by restriction fragment length polymorphism analysis. In contrast, M. tuberculosis isolates from controls with drug-susceptible tuberculosis had patterns distinct from each other and from those of case patients. Conclusions These data suggest nosocomial transmission of multidrug-resistant tuberculosis occurred from patient to patient and from patient to health care worker and underscore the need for effective acid-fast bacilli isolation facilities and adherence to published infection control guidelines in health care institutions.

Exogenous reinfection with multidrug-resistant Mycobacterium tuberculosis in patients with advanced HIV infection.

Abstract: Background In the United States there have been recent outbreaks of multidrug-resistant tuberculosis. These outbreaks have primarily involved persons infected with the human immunodeficiency virus (HIV). Methods We collected clinical information on 17 patients seen at a New York City hospital who had repeatedly positive cultures for Mycobacterium tuberculosis. Analysis of restriction-fragment-length polymorphisms (RFLPs) was performed on serial isolates of M. tuberculosis obtained from these patients. Results Six patients had isolates that remained drug-susceptible, and the RFLP patterns of these isolates did not change over time. Eleven patients had isolates that became resistant to antimicrobial agents. The RFLP patterns of the isolates from six of these patients remained essentially unchanged (two strains showed one additional band) despite the development of drug resistance. In five other patients, however, the RFLP patterns of the isolates changed dramatically at the time that drug resistance was det...

Hospital outbreak of multidrug-resistant Mycobacterium tuberculosis infections. Factors in transmission to staff and HIV-infected patients.

Abstract: Objective. —To describe transmission of multidrug-resistant (MDR)Mycobacterium tuberculosisinfection among patients and health care workers (HCWs) in a ward and clinic for human immunodeficiency virus (HIV)—infected patients in a hospital, four studies were conducted. Methods. —Case patients and control patients were persons who had been treated in the HIV ward or clinic, whose clinical course was consistent with tuberculosis and who had at least one positive culture forM tuberculosisbetween January 1, 1988, and January 31, 1990, resistant to at least isoniazid and rifampin (case patients), or whose isolates were susceptible to all drugs tested (control patients). In the first study, case patients and control patients were compared to identify risk factors for MDR tuberculosis. In the second study, inpatient and outpatient days of MDR tuberculosis case patients were compared to determine whether acid-fast bacillus (AFB) smear-positivity or aerosolized pentamidine use was associated with higher numbers of subsequent MDR tuberculosis cases among exposed patients. In the third study, restriction fragment length polymorphism analysis was performed on available MDR and sensitiveM tuberculosisisolates. In the fourth study, skin test conversion rates among HCWs in the HIV ward and clinic were compared with those of HCWs in another ward, and the strength of the associations between skin test conversions among HCWs on the HIV ward and the number of person-days that AFB smear-positive case patients and control patients were on this ward was estimated. Results. —Case patients were more likely than control patients to have been exposed on the HIV ward or clinic to an AFB smear-positive case patient (P Conclusions. —Nosocomial transmission of MDRM tuberculosisinfection to patients and HCWs occurred on the HIV ward and clinic. Infectiousness of MDR tuberculosis case patients was associated with AFB sputum-smear positivity. Case patients with MDR tuberculosis created a greater risk of skin test conversion for HCWs on the HIV ward than drug-susceptible control patients. (JAMA. 1992;268:1280-1286)