Stenotrophomonas maltophilia as a causative agent of implant-associated infection in trauma and orthopedic patients

Objective. To evaluate an etiologic significance of S. maltophilia in the development of orthopedic implant-associated infections. Materials and methods. The study involved a retrospective analysis of the frequency of excretion of S. maltophilia in patients with periprosthetic infection and osteomyelitis, using the Microbe-2 program in period of 2005–2020. Clinical isolates were excreted according to standard methods. Identification was performed via Microlatest panels using iEMS Reader MF. Antibiotic susceptibility was studied in accordance with EUCAST. Results. Over 16 years 69 strains of S. maltophilia have been identified, comprising 0.33% of all isolated pathogens (n=20631). 50% of isolates were excreted from tissue biopsies, 30% – from wound exudates. In 89% of cases, S. maltophilia was isolated in microbial associations, including 65% of cases together with Grampositive bacteria, 18% with other non-fermenting Gram-negative bacteria, and 6% with other pathogens. 63% appeared sensitive to trimethoprim/sulfamethoxazole and 25.5% of isolates were resistant. The proportion of cultures sensitive to this drug was found to increase from 63% in 2011–2014 to 81% in 2015–2019 (p = 0.08). Conclusion. S. maltophilia should be considered as a causative etiologic agent of severe chronic orthopedic infections.