Incidence of cmaA2 gene in Beijing and non-Beijing strains of Mycobacteriumtuberculosis strains isolated from clinical specimens

Abstract number: 1733_1491

Amir Mozaffari N.

Objectives: The purpose of this investigation was to determine the prevalence of cmaA2 gene in M. tuberculosis strains of both Beijing and non-Beijing types isolated and typed by spoligotyping. Related risk factors among patients with different nationalities residing in Iran were also determined.

Methods: The study population involved a total of 742 patients that referred to the NRITLD, the referral tuberculosis centre in Iran; during March 21, 2003, till March 21, 2005. The isolated M. tuberculosis strains have been characterised by performing susceptibility tests against four first-line antituberculosis drugs and were then subjected to spoligotype characterisation. PCR was used for detection of cmaA2 gene and its nucleotide sequence was also determined.

Results: Spoligotyping of M. tuberculosis strains resulted in 150 different patterns. One hundred thirty five (90%) of these spoligotype isolates were unique and reported for the first time. The remaining 15 (10%) spoligotype patterns were previously reported from other geographical regions of the world. East African Indian (EAI) family was most prevalent than the other genotypes. Interestingly, 6.1% of the strains belonged to the Beijing family. Multidrug-resistance M. tuberculosis isolates were obtained from 13.6% of the patients during this study. The cmaA2 gene was detected in M. tuberculosis clinical isolates, but not in saprophytic strains such as M. kansasi. The other risk factors such as sex and age were also contributing factors to the disease state.

Conclusion: The results showed that multidrug-resistant bacteria were more prevalent in Iranian tuberculosis patients. In addition, the spread of M. tuberculosis strains belonging to the Beijing family among Iranian patients has to be considered seriously. This study confirmed the widespread existance of cmaA2 gene in almost all clinical isolates. It is also important to undertake studies to identify which factors are the most significant to consider in tuberculosis control programme.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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