Objective: Lautropia mirabilis is a rare Gram-negative opportunistic pathogen, with limited clinical understanding of the infectious diseases it causes. This study aims to provide reliable experimental data for epidemiological analysis, monitor in vitro antibiotic susceptibility, and guide clinical treatment through the identification of this bacterium and in vitro drug susceptibility testing, along with an analysis of patient clinical data. Methods: From March to August 2024, sputum or bronchoalveolar lavage specimens from patients in Shanghai and Guangxi were collected and cultured, resulting in the isolation of 38 strains of L. mirabilis . The demographic characteristics, clinical manifestations, imaging, and microbiological data of the patients were analyzed. Identification of the strains was performed using 16S rRNA polymerase sequencing and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and in vitro drug susceptibility tests were conducted to study the microbiological characteristics of L. mirabilis . Cluster analysis was performed using mass spectrometry, and molecular phylogenetic tree analysis was conducted to evaluate the differences among strains from different regions. Results: A total of 38 patients infected with L. mirabilis were collected, and the majority of these patients had underlying diseases. All infected patients received antibacterial treatment during hospitalization and were discharged after recovery. The identification accuracy of the strains at the species and genus levels using 16S rRNA polymerase chain reaction sequencing and MALDI-TOF MS was 100%. Cluster and phylogenetic tree analyses revealed no significant differences among different regions and strains. Conclusion: L. mirabilis poses a higher susceptibility risk in elderly patients with underlying diseases or weakened immunity. This bacterium is fully sensitive to cephalosporins, aminoglycosides, and carbapenem antibiotics, while the resistance rate to fluoroquinolone antibiotics exceeds 50%. This study provides a more comprehensive understanding of this bacterium and offers a more thorough reference for clinical treatment of such diseases. Keywords: Lautropia mirabilis , infection, drug resistance, risk factors
Liang et al. (Thu,) studied this question.