Distribution of Mycobacterium avium complex in clinical specimens between ۲۰۱۸-۲۰۱۹ (before COVID-۱۹ pandemic) and ۲۰۲۰-۲۰۲۱ (during COVID-۱۹ pandemic)

Backgrounded: Non-tuberculous mycobacteria (NTMs) are a diverse and large group of species in the genus Mycobacterium. Mycobacterium avium complex is the second most common group of human pathogens after Mycobacterium tuberculosis complex which cause opportunistic infections in patients andrespiratory infections in healthy individuals and immunocompromised patients. Method: A total of ۱۶,۸۹۹ clinical samples were collected from the National Research Institute of Tuberculosis and Lung Disease (NRITLD), Shahid Beheshti University of Medical science, Tehran, Iran between ۲۰۱۸ and ۲۰۲۱. Samplesincluded patients suspected of Mycobacterium, hospitalization, as well as referral samples to this center. initial isolation of Mycobacterium spp. was performed on Lowenstein-Jensen media. Then DNA was extracted from the patients' samples. To identify Mycobacterium species (tuberculosis and non-tuberculousmycobacteria), the IS۶۱۱۰, Hsp۶۵, and ۱۶S-۲۳S rRNA genes using based on PCR, PCR-RFLP and Nested – PCR methods. Result: In general, ۲۴۴ NTMs were isolated among the collected samples of ۲۰۱۸-۲۰۱۹ (before COVID-۱۹ pandemic) (۱۱۶۷۹/۱۶۸۹۹; ۶۹.۱۱%). The number of positive samples for M. aviumspecies was ۳/۲۴۴; ۱.۳۴% and M. intracellul ar ۳۵/۲۴۴; ۱۵.۶۳%. Also, among the samples between ۲۰۲۰- ۲۰۲۱ (during COVID-۱۹ pandemic) (۵۲۲۰/۱۶۸۹۹; ۳۰.۸۹%), a total of ۱۸۷ NTMs were identified and isolated. Among NTMs, M. avium was ۷/۱۸۷; ۳.۷۴% and M. intracellular was ۲۹/۱۸۷; ۱۵.۵۱%.Conclusion: Due to the ۳۸.۲۲% decrease in sample Referred to NRITLD during the COVID-۱۹ pandemic compared to before the pandemic (۱۱۶۷۹/۵۲۲۰), we have seen an increase in the incidence of M. avium isolates. The increasing prevalence of NTMs is very alarming and needs more attention in the community.

Keywords:

Mycobacterium avium complex , non-tuberculous mycobacteria , Mycobacterium tuberculosis , COVID-۱۹ pandemic