Ceftolozane-tazobactam and Fosfomycin for rescue treatment of otogenous meningitis caused by XDR Pseudomonas aeruginosa: Case report and review of the literature

•Infections due to XDR Pseudomonas are at increased risk of complications and death.•CNS involvement may be due to poor CNS penetration of drugs with residual activity.•XDR-PA meningitis ensued during treatment with colistin for pneumonia and bacteremia.•CNS involvement by XDR-PA was timely suspected and quickly documented on CSF.•High dose C-T and Fosfomycin provided rapid control of meningitis. Extensively drug resistant Pseudomonas aeruginosa (XDR-PA) strains with limited or absent residual antimicrobial susceptibility cause a growing burden of difficult-to treat infections. Treatment options are even more limited for patients with central nervous system (CNS) involvement, as colistin-based regimens are hampered by poor blood brain barrier penetration, being often associated with insufficient clinical and microbiological success. New treatment options are awaited, but evidence from prospective evidence-based evaluations is still lacking. Here we report a case of breakthrough otogenous meningitis caused by XDR-PA in a young patient treated with meropenem and colistin for XDR-PA bloodstream infection and pneumonia after a car-crash polytrauma. The patient was treated with off-label, high-dose ceftolozane-tazobactam and high-dose fosfomycin after characterization of CNS XDR-PA isolates, with rapid clinical and microbiological resolution of meningitis. Our experience, although based on a single case, lands preliminary support to the concept that rescue regimens including ceftolozane-tazobactam and fosfomycin may be considered for XDR-PA CNS infections in patients without alternative therapeutic options.