Identification and Determination of Antibiotic Resistance Pattern of Stenotrophomonas maltophilia Isolated form Medical Devices and Clinical Samples in Jahrom,s Hospitals by Phenotype and Molecular Methods

Stenotrophomonas maltophilia is an important cause of nosocomial infections. The bacteria is a non-fermentative Gram-negative bacilli. S. maltophilia is a newly emerging pathogen of growing significance that has been more frequently isolated in nosocomial specimens, hospital waters and Disinfection solutions. S. maltophilia is inherently resistant to many antimicrobial drugs that cause a significant challenge in treatment of infections. Most strains of this bacteria are resistant to many antibiotics, including:Carbapenems,Macrolides,Cephalosporins,Fluoroquinolones,Aminoglycosides.This bacteria is MDR (Multiple Drug Resistance).
In this study, 170 samples from medical equipment and 250 clinical samples were collected randomly from patients who were referred to hospitals in Jahrom city. Samples were transported to the laboratory in sterile containers. Then were cultured on phenotypic differential medium .After isolation of the bacteria, Gram staining was performed to detect Gram-negative bacilli. After the identification of Gram-negative bacilli, biochemical and differential tests were performed to identify the genus and species of S. maltophilia. Molecular diagnostic tests (PCR) was performed for confirmation of bacteria.
Of the 250 clinical specimen, 14 samples (5.6%) and of the 170 samples collected from medical equipment, only 1 sample (0.6%) were positive. Positive samples were studied in terms of sensitivity to several antibiotics. Antibiotics were included: Ticarcillin (71.4%), Ceftazidime (64.3%), Levofloxacin (78.57%), Trimethoprim-sulfamethoxazole (7.14%), Chloramphenicol (28.57%), Aztreonam (64.3%), Imipenem (71.4%).
According to prevalence, high levels of antibiotic resistance and increase of multiple drug resistance (MDR) in stenotrophomonas maltophilia, identification and determination of antibiotic resistance is essential and recommended for treatment of opportunistic infection caused by this bacteria. It also recommended that further studies be conducted periodically in hospital on colonization of this bacteria for prevention and control.