Prevalence of Mycobacterium chelonae in patients referred to the National Tuberculosis Reference Laboratory of Iran (۲۰۱۲-۲۰۲۲)

Introduction: Mycobacterium chelonae is classified as non-tuberculous mycobacteria. This bacterium is also the cause of many lung and skin diseases, especially in people with immunodeficiency. Also, due to the possibility of increasing the number of diseases caused by Mycobacterium chelonae worldwide, wehave conducted a study to evaluate this strain in Iran. Materials and methods: This cross-sectional descriptive study was performed on ۶۴۲۲ samples isolated from pulmonary tuberculosis patients referred to the national tuberculosis reference laboratory of Masih Daneshvari Hospital between ۲۰۱۲ and ۲۰۲۲. DNA was extracted from the samples of these patients by chloroform method. Primer was selected for IS۶۱۱۰ target gene and after confirmation of sensitivity andspecificity, optimal PCR test was performed on the samples. Specimens with negative IS۶۱۱۰ based on PCR test were analyzed for Mycobacterium chelonae using hsp۶۵ gene by PCR-RFLP method. Results: The results of PCR-RFLP test were observed by agarose gel electrophoresis ۱.۵%. Out of a totalof ۶۴۲۲ samples, ۷۲۳ (۱۱.۲۶%) NTM strains were identified. Also, out of a total of ۷۲۳ (۱۱.۲۶%) NTM samples identified, ۲۵ (۳.۴۶%) samples belonged to Mycobacterium chelonae. The mean age of patients with Mycobacterium chelonae was ۱۷.۵ ± ۶۰ years (ranging in age from ۷ to ۸۰ years). Of these, ۱۹ weremale and ۵ were female. The results also showed that the prevalence of Mycobacterium chelonae in terms of provincial distribution has significant statistics.Conclusion: In this study, we observed a significant prevalence of Mycobacterium chelonae in patients with pulmonary tuberculosis. Due to the fact that the treatment protocol of this type of mycobacterium is different from other mycobacteria, so timely diagnosis of this mycobacterium can be very important fordoctors. The first step in treating the disease is to diagnose it quickly and accurately. Due to the fact that Mycobacterium chelonae is one of the fast-growing mycobacteria and the identification of this bacterium through culture and biochemical tests is very difficult. The results of the study showed that their rapid andtimely detection through PCR-RFLP it can provide the correct treatment.

Keywords:

Mycobacterium chelonae , NTM strains , hsp۶۵ gene , identification , treatment , Prevalence