Trimethoprim/sulfamethoxazole (co-trimoxazole) prophylaxis is effective against acute murine inhalational melioidosis and glanders

Burkholderia pseudomallei is the causative agent of the disease melioidosis, which is prevalent in tropical countries and is intractable to a number of antibiotics. In this study, the antibiotic co-trimoxazole (trimethoprim/sulfamethoxazole) was assessed for the post-exposure prophylaxis of experimental infection in mice with B. pseudomallei and its close phylogenetic relative Burkholderia mallei, the causative agent of glanders. Co-trimoxazole was effective against an inhalational infection with B. pseudomallei or B. mallei. However, oral co-trimoxazole delivered twice daily did not eradicate infection when administered from 6 h post exposure for 14 days or 21 days, since infected and antibiotic-treated mice succumbed to infection following relapse or immunosuppression. These data highlight the utility of co-trimoxazole for prophylaxis both of B. pseudomallei and B. mallei and the need for new approaches for the treatment of persistent bacterial infection.