Is standardized treatment appropriate for non-XDR multiple drug resistant tuberculosis cases? A clinical descriptive study

The clinical relevance of second-line drug susceptibility test (DST) results with respect to treatment outcome is unknown in non-XDR MDR patients. This study was carried out in the sole national referral centre for TB in Iran between 2002 and 2006. Multidrug-resistant tuberculosis (MDR-TB) patients who had DST to second-line drugs were included. For all MDR-TB patients the standard second-line regimen was initiated. Outcome of treatment based on DST to second-line drugs was analysed. 53 patients were included. DST for second-line drugs was available for 40 patients. Seven patients returned to Afghanistan during treatment. Among the remainder, 13 (30.4%) cases were Iranian. Mean age was 40.8 + 19.7 y. The relatively small sample size imposes some limitations on this study. However, in this study, there was no difference in resistance to second-line drugs by nationality. No significant correlation was seen between resistance to second-line drugs and outcome of treatment. In conclusion, the treatment outcome according to WHO definitions was appropriate in the study population by the use of standardized treatment regimens. Follow-up studies on a long-term basis are however needed in order to detect possible relapses

Study of Mycobacterium bovis genotypes in human and bovine isolates using spoligotyping, MIRUVNTR and RFLP-PCR

Aims and objectives: The aim of this study is to investigate and detect the prevalence of Mycobacterium bovis subtypes (Mycobacterium bovis subtype bovis and Mycobacterium bovis subtype caprae) in humans and compare the genetic diversity of Mycobacterium bovis in humans and cattle with spoligotyping methods, as well as pyrazinamide susceptibility study of subtypes. Methods: Examining these subtypes with molecular epidemiology techniques is particularly important due to different treatment of M. bovis diverse subtypes in humans. Culture tests were performed on clinical samples that were isolated from Lowenstein-Jensen culture medium. Identification tests were performed to differentiate Mycobacterium bovis from Mycobacterium tuberculosis. DNA was extracted and spoligotyping (spacer oligonucleotide typing) was performed using the DRb and DRa primers. Results: The results were analyzed with the SPOLDB4 site. PCR-RFLP method of pncA gene was used to evaluate the resistance to pyrazinamide and pncA gene polymorphism. Conclusions: Mycobacterium bovis subtype bovis in the Iranian population was reported with a frequency of 0.6% which was below the average of the previous reviews. In this study, all the strains were M. bovis subtype bovis resistant to pyrazinamide. No Mycobacterium bovis subtype caprae was detected. The only shared ST between humans and cattle was ST694. Mycobacterium bovis subtype bovis with ST 595 was reported as human bovis index

First-line anti-tuberculosis drug resistance patterns and trends at the national TB referral center in Iran—eight years of surveillance

Resistance to anti-tuberculosis (anti-TB) drugs is becoming a major and alarming threat in most regions worldwide. This was a descriptive cross-sectional study at a tertiary hospital in Iran, using patient medical records for 2000–2003. The findings were analyzed following the same framework as that used for previous reports from this center. Among 1556 TB patients, drug susceptibility testing (DST) was performed for 548 culture-positive cases. Anti-TB drug resistance to both isoniazid and rifampin was identified in 10 (2.8%) of the new TB cases (multidrug-resistant TB; MDR-TB). Any resistance was detected in 228 (41.6%), showing an increasing trend in both new and retreatment cases. The data analysis revealed that drug-resistant TB had a statistically significant association with Afghan ethnicity, age >65 years, and the type of disease (retreatment vs. new TB case) ( p < 0.05). Also, assessment of the drug resistance trends showed a significant increase in resistance to any anti-TB agent, to isoniazid, and to streptomycin in new cases, and to all of the first-line anti-TB drugs in retreatment patients. There has been an increasing trend in drug resistance in recent years, particularly in retreatment cases. Hence, revision of the national TB control program, reevaluation of the role of the World Health Organization category II (CAT II) regimen, as well as the conducting of a nationwide drug resistance survey, are recommended

Utility of Gastric Lavage for Diagnosis of Tuberculosis in Patients who are Unable to Expectorate Sputum

Background: There are number of patients who are unable to expectorate sputum specimens. In this study, we used gastric lavage (GL) test for diagnosis of tuberculosis (TB) in patients who were unable to produce sputum. Materials and Methods: Patients who were unable to produce sputum specimens were included in the study to confirm TB disease. Gastric lavage sampling was performed and sent for acid fast bacillus smear and culture under special laboratory conditions and sterilized methods. Further bronchoscopy for broncho-alveolar lavage was done on patients with negative GL smear results. Drug susceptibility tests were performed on 48 GL culture positive cases. Results: Eighty-five patients were included in the study; who were hospitalized at our referral center for suspected TB. GL smears were reported to be positive in 37 cases (66.07%) and culture in 85.7%. The total number of smear and culture-positive cases in this study was 48 (85.7%). Forty cases (87%) of drug-sensitive, 1 case (2.2%) of isoniazid and rifampin-resistant TB (multi-drug resistant; MDR), and 5 cases of resistant to one drug were detected. There have not been observed any complications after the GL method. Conclusion: It seems that regarding the high number of positive GL cultures (85.7%), GL can be effective for diagnosis of patients who have suspicious tuberculosis symptoms and are unable to produce sputum especially in resource limited areas