Antimicrobial Susceptibility of Stenotrophomonas maltophilia Clinical Isolates from Blood Samples in Iran

Stenotrophomonas maltophilia is a nosocomial multi drug resistant opportunistic pathogen which causes infections in vulnerable patients with cancer, cystic fibrosis and indwelling catheters.
45 clinical S. maltophilia isolates were collected from blood samples and identified by biochemical tests. Susceptibility to different antibiotics including co-trimoxazole, levofloxacin, minocycline, ticarcillin/clavulanic acid, chloramphenicol and ceftazidime were determined by disk diffusion and E-test methods.
All isolates were resistant to ceftazidime and susceptible to co-trimoxazole and 11.1% were resistant to ticarcillin/clavulanic acid.
Ceftazidime as one of the extended spectrum β-lactams was the least effective antibiotic. Ticarcillin/clavulanic acid is one of the choosen antibiotics for S. maltophilia infections treatment. Here, we report tcarcillin/clavulanic acid resistance in S. maltophilia isolates for the first time in Iran.