Case report: Pneumonia in an elderly Tibetan male caused by Shewanella algae

Abstract

Background Shewanella algae is a gram-negative bacterium that is widely found in aquatic habitats and rarely causes lung infections in inland areas. Case presentation This case report presents the clinical presentation and treatment of a 68-year-old Tibetan male who developed cough, phlegm, chills, fatigue, and shortness of breath. Laboratory tests showed elevated white blood cell count（WBC10030/ul） and procalcitonin levels（PCT0.067ng/ml）, and chest CT revealed scattered lesions. A gram-negative bacterium was isolated from lower respiratory tract specimens and identified as Shewanella algae using various techniques including BioMerieux VITEK 2 Compact, MALDI-TOF-MS (Autof ms1000), and 16S rRNA gene sequence analysis. The patient's lung infection improved after one week of treatment with ceftazidime, and he was discharged. Conclusion This case highlights a rare occurrence of lung infection caused by Shewanella algae in elderly Tibetan men residing in non-marine environments.