en Epidemiologic studies including microbial genotyping, phenotyping and serotyping Epidemiologic studies including microbial genotyping, phenotyping and serotyping Original article Original article <b><span style="font-size:10.0pt"><span style="background:white"><span style="line-height:115%"><span new="" roman="" style="font-family:" times="">Introduction:</span></span></span></span></b><span style="font-size:10.0pt"><span style="background:white"><span style="line-height:115%"><span new="" roman="" style="font-family:" times=""> In HIV-associated tuberculosis cases, identifying nontuberculous <i>Mycobacteria</i> (NTM) from clinical samples has become essential regarding patients&rsquo; treatment and prognosis. This study aims to determine the prevalence of different <i>Mycobacteria</i> species </span></span></span></span><span style="font-size:10.0pt"><span style="line-height:115%"><span new="" roman="" style="font-family:" times="">from immunocompromised and immunocompetent patients with suspected tuberculosis attending a tertiary care hospital in Kolkata, India. <b>Methods<i>:</i></b> </span></span></span><span style="font-size:10.0pt"><span style="line-height:115%"><span new="" roman="" style="font-family:" times="">Clinical samples from 112 suspected tuberculosis patients were examined by direct microscopy after</span></span></span><span style="font-size:10.0pt"><span style="line-height:115%"><span new="" roman="" style="font-family:" times=""> Ziehl&ndash;Neelsen</span></span></span><span style="font-size:10.0pt"><span style="line-height:115%"><span new="" roman="" style="font-family:" times=""> staining. After culture in BacT/ALERT 3D mycobacterial culture system, identification of the causative agents was performed using the GenoType MTCM system. <b>Results: </b>C</span></span></span><span style="font-size:10.0pt"><span style="line-height:115%"><span new="" roman="" style="font-family:" times="">ulture positivity was higher in immunocompromised patients than in immunocompetent in both pulmonary and extrapulmonary samples. In smear-negative samples, culture positivity in immunocompromised patients (50%) was much higher than in immunocompetent patients (26.67%). </span></span></span><span style="font-size:10.0pt"><span style="line-height:115%"><span new="" roman="" style="font-family:" times="">Of 78 samples, </span></span></span><span style="font-size:10.0pt"><span style="line-height:115%"><span new="" roman="" style="font-family:" times="">four were</span></span></span><span style="font-size:10.0pt"><span style="line-height:115%"><span new="" roman="" style="font-family:" times=""> NTMs (5.13%), including 1 <i>M. avium</i>, 1 <i>M. abscessus,</i> and 2 <i>M. fortuitum</i>, and 74 were <i>Mycobacterium tuberculosis</i> (MTBC). Two NTMs belonged to immunocompromised patients and two to immunocompetent individuals. The chance of Mycobacterial infection was higher in patients with a lower CD4 count. Both NTMs found in the immunocompromised group were from patients with a CD4 count<100. <b>Conclusion: </b>The present study showed that the MTBC is<i> </i>still the primary causative agent in pulmonary and extrapulmonary tuberculosis in this part of India. </span></span></span> Tuberculosis,NTM,Immunocompromised,CD4 count. 10 13 http://jommid.pasteur.ac.ir/browse.php?a_code=A-10-378-1&slc_lang=en&sid=1 Soumya Dasgupta soumyadgoptimus@gmail.com 0000-0001-6129-6675 Yes MJN Medical College and Hospital, Coochbehar. West Bengal. India. Zip – 736101 Oindrila Chakraborty oindrila.c@manipal.edu 0000-0002-8089-0968 No Manipal-Tata Medical College, Jamshedpur. Jharkhand. India. Zip – 831017