Meropenem as a non-guideline antibiotic: the factor associated with mortality of mortality in Listeria monocytogenes meningitis

BackgroundListeria monocytogenes meningitis has high mortality. Evidence on meropenem’s real-world efficacy in Chinese adults is lacking.MethodsThis retrospective study of 19 Listeria meningitis cases used CSF/blood culture and ROC analysis for diagnosis, and applied Fisher’s exact test to explore the association between meropenem treatment and mortality.ResultsIn 19 patients with L. monocytogenes meningitis (median age 56 years, male/female 2.16:1), L. monocytogenes was the second most common cause (70.3% of Listeria infections). Underlying diseases were present in 10 patients, and MRI showed periventricular changes (9 cases), bifrontal lesions (2), hydrocephalus (1), and normal findings (4). Of 10 CSF-positive patients, 2 had concurrent positive blood cultures; mean time to blood culture positivity was 19.3 ± 9.3 h. All tested isolates were susceptible to ampicillin, penicillin, TMP-SMX (Trimethoprim-sulfamethoxazole), and meropenem. Serum PCT (AUC = 0.980), CSF WBC (AUC = 1.000), and CSF protein (AUC = 0.959) showed excellent diagnostic performance. In exploratory univariate analysis, Fisher’s exact test identified non-guideline antibiotic administration as the factor associated with mortality of mortality (p = 0.035).ConclusionNon-guideline antibiotic use (meropenem) was the factor associated with mortality of mortality in adult L. monocytogenes meningitis (40% mortality). First-line therapy should remain ampicillin/penicillin; meropenem should be reserved for alternative use only based on existing guidelines, not on the findings of this study alone.