Carriage of multiple resistance genes by community and hospital isolates of Stenotrophomonas maltophilia resistant to the first-line drug of choice in Nigeria.

Stenotrophomonas maltophilia (S. maltophilia) has emerged as an important nosocomial pathogen and causes life-threatening infections among the vulnerable, and occasionally in immunocompetent individuals. We examined the mechanisms of multidrug resistance in S. maltophilia isolated from sick and healthy individuals in Nigeria. Susceptibility testing and genome sequencing revealed multidrug resistance and carriage of multiple antimicrobial resistance genes in all isolates. Genes encoding resistance to fluoroquinolones, beta-lactams, aminoglycosides, chloramphenicol, sulphonamide and trimethoprim including oqxB, bla1_3, aph(3), cmlB1, sul and dfrA, variants were found in all the isolates. Genome analysis revealed multiple plasmids were present in the strains including ColBS512, ColMG828, and IncR plasmids. Resistance to multiple drugs compromises the treatment option for S. maltophilia limiting a potential treatment option that can cause serious nosocomial infections.