A correlação entre a resistência à pirazinamida (PZA) e a resistência a outros fármacos antituberculose de primeira linha foi investigada em 395 cepas de Mycobacterium tuberculosis provenientes de espécimes clínicos, que representavam 14% do total de isolados de M. tuberculosis no período entre 2003 e 2008 no laboratório de um hospital universitário de referência para tuberculose. Uma alta correlação foi encontrada entre resistência a PZA e multirresistência, assim como entre resistência a PZA e resistência a rifampicina, isoniazida e etambutol (p < 0,01 para todos). Esses resultados enfatizam a importância da realização do teste de sensibilidade a PZA antes de prescrever a droga para o tratamento de tuberculose resistente e multirresistente.

The correlation between resistance to pyrazinamide (PZA) and resistance to other first-line antituberculosis drugs was investigated in 395 Mycobacterium tuberculosis strains isolated from clinical specimens, representing 14% of the overall number of M. tuberculosis isolates obtained between 2003 and 2008 at the laboratory of a referral university hospital for tuberculosis. A high correlation was found between resistance to PZA and multidrug resistance, as well as between PZA resistance and resistance to rifampin, isoniazid, and ethambutol (p < 0.01 for all). These results highlight the importance of performing PZA susceptibility testing prior to the prescription of this drug in order to treat drug-resistant and multidrug-resistant tuberculosis.

The performance of the nitrate reductase assay (NRA) was compared with the proportion method (PM) on Lowenstein-Jensen medium and the BACTEC MGIT960 assay under routine conditions using 160 clinical isolates of Mycobacterium tuberculosis with a high proportion of resistant strains. The mean time to obtain results was 8.8 days and the overall agreements between NRA and PM and NRA and M960 were 95% and 94%, respectively. NRA was easy to perform and represents a useful tool for the rapid screening of drug-resistant M. tuberculosis strains in low-resource countries.

We describe a case of a male patient, 38 years old, HIV-positive (most recent CD4 count about 259/mm³), with abdominal pain, nausea, vomiting, anorexia, weight loss, and vespertine high fever with chills. His hemogram showed normocytic and normochromic anemia, with a high erythrocyte sedimentation rate (ESR) and gross granulations in the neutrophils. Transaminases were normal. Bone marrow biopsy evidenced a chronic disease anemia pattern and a lack of infectious agents. Abdominal ultrasound examination showed a normal-size spleen, which exhibited heterogeneous parenchyma and multiple small hypoechoic images, together with small ascites, peripancreatic and para-aortic lymphadenopathy. These findings were confirmed by abdominal CT. The liver was normal in size, but had a hyperechoic image, which was not visualized on CT. Histopathological analysis of one of the multiple abdominal lymph nodes obtained by laparoscopic biopsy exhibited a chronic granulomatous inflammatory process, with caseous necrosis. Tissue sections were positive for BAAR (acid-alcohol-resistant bacillus), and the cultures were positive for Mycobacterium tuberculosis. Anti-tuberculosis treatment was begun, and the patient evolved with improvement of his general state, fever remission and weight gain. Splenic tuberculosis is a rare disease, occurring predominantly in patients in late stages of AIDS and/or disseminated tuberculosis. It is a difficult diagnosis, since there are no specific findings. Hence, complementary examinations, such as abdominal ultrasound/ CT, or fine needle aspiration, are usually necessary for investigation and differential diagnosis. Often, lesion regression after anti-tuberculosis regimens can be seen, and splenectomy is restricted to complicated or refractory disease.