en Molecular Microbiology Molecular Microbiology مقاله کامل Full Length/Original Article <strong>Background:</strong> <em>Stenotrophomonas maltophilia</em> is an opportunistic bacterium, contributing to different hospital-acquired infections and can be acquired from different hospital setting sources. Epidemiological study of <em>S. maltophilia </em>in the hospital also demonstrates the intrahospital distribution of certain strains of bacteria in healthcare facilities. The aim of the current study was to identify the molecular epidemiology of <em>S. maltophilia</em> isolates from clinical and environmental sources within a hospital. &nbsp;<br> <strong>Methods:</strong> A total of 400 samples (clinical and environmental) were collected from the different settings of hospital. Following the standard biochemical testing and 23S rRNA genotyping, the molecular typing of <em>S. maltophilia</em> isolates was determined using the multilocus sequence typing (MLST) technique. Also, the frequencies of <em>zot</em> and <em>entF</em> virulence genes among <em>S. maltophilia</em> isolates were examined by PCR technique. &nbsp;<br> <strong>Results:</strong> Based on the biochemical testes and PCRs targeting 23S rRNA gene, 22 <em>S. maltophilia</em> isolates were identified. The MLST analysis demonstrated that these isolates were assigned to 14 ST, and 6 out of 14 STs were common among clinical and environmental samples. All 22 isolates were identified in the PubMLST database. The PCR screening demonstrated that none of 22 <em>S. maltophilia</em> isolates had <em>zot</em> virulence gene, while the <em>entF</em> gene with the 59% frequency was observed in 13 out of 22 isolates. Among these 13 isolates, 6 STs were common in clinical and environmental isolates.<br> <strong>Conclusion:</strong> Our study showed the clonal relatedness between clinical and environmental sources of the <em>S. maltophilia</em> isolates in a hospital. Further studies are required to understand the epidemic situation of this pathogen in the clinic and the environment. Environment, Multilocus sequence typing, Stenotrophomonas maltophilia 142 152 http://ibj.pasteur.ac.ir/browse.php?a_code=A-10-4403-1&slc_lang=en&sid=1 Sinasadat Emami sina.emami2021@yahoo.com 0000-0002-0021-8734 No Microbiology Department of Islamic Azad University, North Tehran Branch, Iran Jamileh Nowroozi NowrooziJ@yahoo.com 0000-0003-4735-9208 Yes Microbiology Department of Islamic Azad University, North Tehran Branch, Iran Ramin Abiri Ramin_abiri@yahoo.com 0000-0002-4657-2413 No Department of Microbiology, Kermanshah University of Medical Science, Kermanshah, Iran Parviz Mohajeri Pmohajeri@kums.ac.ir 0000-0002-2596-264x No Department of Microbiology, Kermanshah University of Medical Science, Kermanshah, Iran