Successful Treatment of Carbapenem-Resistant Acinetobacter baumannii Meningitis with Sulbactam-Durlobactam.

BACKGROUND: The treatment of carbapenem-resistant Acinetobacter baumannii/calcoaceticus complex (CRAB) presents significant treatment challenges. METHODS: We report the case of a 42-year-old woman with CRAB meningitis who experienced persistently positive cerebrospinal fluid (CSF) cultures for 13 days despite treatment with high-dose ampicillin-sulbactam and cefiderocol. On day 13, she was transitioned to sulbactam-durlobactam and meropenem; four subsequent CSF cultures remained negative. After 14 days of sulbactam-durlobactam, she was cured of infection. Whole genome sequencing investigations identified putative mechanisms that contributed to reduced cefiderocol susceptibility observed during cefiderocol therapy. Blood and CSF samples were collected pre-dose and 3-hours post initiation of a sulbactam-durlobactam infusion. RESULTS: The CRAB isolate belonged to sequence type 2. An acquired blaOXA-23 and an intrinsic blaOXA-51-like (i.e., blaOXA-66) carbapenemase gene were identified. The paradoxical effect (i.e., no growth at lower cefiderocol dilutions but growth at higher dilutions) was observed by broth microdilution after 8 days of cefiderocol exposure but not by disk diffusion. Potential markers of resistance to cefiderocol included mutations in the start codon of piuA and piuC iron transport genes and a A515V substitution in PBP3, the primary target of cefiderocol. Sulbactam and durlobactam were detected in CSF at both timepoints, indicating CSF penetration. CONCLUSIONS: This case describes successful treatment of refractory CRAB meningitis with the administration of sulbactam-durlobactam and meropenem and highlights the need to be cognizant of the paradoxical effect that can be observed with broth microdilution testing of CRAB isolates with cefiderocol.

Leuconostoc mesenteroides bacteremia in a patient with exposure to unpasteurised raw milk.

Leuconostoc spp are lactic acid-producing bacteria closely related to the Streptococcus family. While usually associated with the fermentation of dairy products and sauerkraut, they are rarely associated with human infections. This is a case report of an immunocompetent patient found to have L. mesenteroides bacteremia associated with raw milk and poor dentition as the likely source of infection, which was treated successfully with daptomycin as this genus is intrinsically resistant to vancomycin.

Case report: Disseminated aspergillosis complicating influenza.

Aspergillus can cause a wide variety of diseases ranging from hypersensitivity diseases to invasive infection. Invasive disease most commonly occurs in severely immunocompromised patients such as chemotherapy-induced neutropenia and transplantation. It is a less well-recognized complication in critically ill patients without traditional risk factors. We describe a case of invasive aspergillosis complicating influenza and diabetic ketoacidosis that disseminated to the central nervous system and led to demise despite high-intensity antifungal therapy.