Genotypic diversity of Mycobacterium tuberculosis in Buenos Aires, Argentina.

Buenos Aires is an overpopulated port city historically inhabited by people of European descent. Together with its broader metropolitan area, the city exhibits medium tuberculosis rates, and receives migrants, mainly from tuberculosis highly endemic areas of Argentina and neighboring countries. This work was aimed to gain insight into the Mycobacterium tuberculosis population structure in two suburban districts of Buenos Aires which are illustrative of the overall situation of tuberculosis in Argentina.

AIDS pacient's long-term battle with multiply recurrent tuberculosis: reinfection or reactivation?

The advent of Mycobacterium tuberculosis strain genotyping has allowed differentiation between disease relapse and exogenous re-infection. We report here a remarkable case of multiply recurrent tuberculosis in a patient living with HIV. Between 1995 and 2009, a young HIV-infected intravenous drug user, who was reluctant to comply with anti-retroviral treatment, underwent at least five tuberculosis episodes caused by three distinct M.

Comparative molecular study of Mycobacterium tuberculosis strains, in times of antimicrobial drug resistance.

Strains of Mycobacterium tuberculosis were compared using two DNA fingerprinting techniques: Restriction Fragment Length Polymorphism (RFLP) and Double-Repetitive-Element-PCR (DRE-PCR). Two of these strains: IH1 (susceptible to isoniazid) and IH2 (resistant to isoniazid) were recovered from cases of pulmonary tuberculosis which occurred in two brothers who lived together. The first one was recognized on July 1999, and the second was diagnosed one year later.

[Distribution of PRA patterns of clinical isolates of the Mycobacterium avium complex from Spain and South America].

Mycobacterium avium complex (MAC) infections are the most frequent systemic infections associated with advanced AIDS. DNA probes for accurate identification of mycobacteria are available but are very expensive in many Latin American settings. Consequently, most Latin American diagnostic laboratories employ inaccurate and outdated tests for mycobacteria identification.

[False-positive cultures due to cross contamination in tuberculosis laboratories].

Fifteen episodes of Mycobacterium tuberculosis laboratory cross-contamination suspected between 1996 and 2001 at 6 laboratories in Buenos Aires City and suburbs were investigated by IS6110 RFLP. Thirteen episodes were confirmed. Even though BACTEC 460 produced the highest number of confirmed episodes in a single laboratory, the most extended one occurred while employing conventional culture procedures in solid medium.

[Study of Mycobacterium bovis in milk using bacteriological methods and the polymerase chain reaction].

The frequency of Mycobacterium bovis detection in milk samples obtained from infected animals was explored in an intensive dairy area in Argentina. To this end, an "in house" polymerase chain reaction (PCR) method was developed using Mycobacterium tuberculosis Complex specific INS1-INS2 primers, and its performance was compared with that of bacteriological methods. The decontamination procedures previous to culture reduced M.

Global trends in resistance to antituberculosis drugs. World Health Organization-International Union against Tuberculosis and Lung Disease Working Group on Anti-Tuberculosis Drug Resistance Surveillance.

Background: Data on global trends in resistance to antituberculosis drugs are lacking.

Methods: We expanded the survey conducted by the World Health Organization and the International Union against Tuberculosis and Lung Disease to assess trends in resistance to antituberculosis drugs in countries on six continents. We obtained data using standard protocols from ongoing surveillance or from surveys of representative samples of all patients with tuberculosis.

Nosocomial spread of human immunodeficiency virus-related multidrug-resistant tuberculosis in Buenos Aires.

A steep upsurge of human immunodeficiency virus (HIV)-associated multidrug-resistant tuberculosis (MDR-TB) was recently observed at a referral treatment center in Buenos Aires City. Between January 1994 and June 1995, TB isolates resistant to at least five drugs were recovered from 101 of 272 HIV-infected inpatients. Highly resistant isolates from 77 patients underwent restriction fragment length polymorphism study with IS6110.

Hospital transmission of multidrug-resistant Mycobacterium tuberculosis in Rosario, Argentina.

Multidrug-resistant tuberculosis has emerged over the last two years at Carrasco Hospital, located in Rosario city. Nosocomial transmission among 7 AIDS patients admitted into the same ward between June and December/94 was supported by temporal clustering of cases, matching drug susceptibility, and identical IS6110 fingerprints. Among 8 non-HIV chronic cases without evidence of reciprocal contact outside the hospital, two additional clusters of 2 and 4 cases, respectively, were identified.

Multidrug resistant tuberculosis outbreak in Buenos Aires. DNA fingerprinting analysis of isolates.

In order to determine the possible relationship among HIV patients coinfected with multidrug resistant tuberculosis strains who had been receiving clinical assistance in our Hospital, clinical and epidemiological information from 28 patients was collected. DNA fingerprinting by restriction fragment length polymorphism (RFLP) pattern was performed on the mycobacterial isolates from these patients, using the restriction enzyme Pvull and IS 6110 as genetic marker. A unique RFLP pattern was found in 10 isolates from 10 different patients who had a disease caused by a single strain.

Humoral response to Mycobacterium tuberculosis in patients with human immunodeficiency virus infection.

The effect of the human immunodeficiency virus (HIV) on mycobacterial antibody production was investigated. Using an enzyme-linked immunosorbent assay (ELISA) for detecting IgG against Mycobacterium tuberculosis PPD, it was observed that individuals at risk of HIV infection show a pattern of humoral response to the tubercle bacillus similar to that previously found in the immunocompetent population not exposed to risk factors: 6 of 12 (50.0%) tuberculosis cases had elevated levels of antibodies to PPD and 27 of 30 (90.