Molecular identification of Stenotrophomonas maltophilia isolated form patients and environments in Kermanshah hospitals

the molecular similarity of S.maltophilia strains between patients and hospital environments in Kermanshah was studied

500 different clinical and environmental samples were collected and cultured for isolation and identification of S.maltophilia isolates using biochemical tests; then presence of 23srRNA gene was detected by PCR for molecular identification. Finally, by amplifying 7 housekeeping genes (including: atpD، gapA، guaA، mutM، nuoD، ppsA and recA) in relation with S.maltophilia bacterium, the strains of S.maltophilia isolates were determined. Then phylogenetic tree was drawn by Mega 7 software.

From 500 clinical and environmental samples collected from hospitals, 28 isolates of S.maltophilia were identified by biochemical methods and molecular confirmation. Among these, 13 isolates were obtained from environmental samples and the rest from clinical samples. A small number of common strains were also found between clinical and environmental samples. Phylogenetic tree analysis demonstrated that these 28 isolates belonged to 21 identified strains of the S.maltophilia, which was due to 100% genetic similarity of some isolates.

The molecular similarity of S.maltophilia strains between patients and hospital environment revealed that all strains of this bacterium in Kermanshah belong to a specific molecular pattern and do not have high genetic diversity and probably, this bacterium was transmitted from the hospital to patients. Therefore, observance of hygiene in hospital and employing the molecular methods with high differentiation is recommended to control the distribution of this bacterium.