Clinical Characteristics of Chronic Lung Abscess Associated with Parvimonas micra Diagnosed Using Metagenomic Next-Generation Sequencing

Abstract

Yaping Zhang,1,2,* Ping Song,1,3,* Ruhui Zhang,1 Yake Yao,1 Lisha Shen,1 Qiang Ma,4 Jianying Zhou,1 Hua Zhou1 1Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310003, People’s Republic of China; 2Department of Respiratory and Critical Care Medicine, Shangyu People’s Hospital, Shaoxing, Zhejiang, 312300, People’s Republic of China; 3Department of Critical Care Medicine, Deqing People’s Hospital, Huzhou, Zhejiang, 313200, People’s Republic of China; 4Department of Respiratory Diseases, Yuhang Second People’s Hospital, Hangzhou, Zhejiang, 311100, People’s Republic of China*These authors contributed equally to this workCorrespondence: Hua Zhou; Jianying ZhouDepartment of Respiratory and Critical Care Medicine, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310003, People’s Republic of ChinaEmail [email protected]; [email protected]: Parvimonas micra (P. micra) is a Gram-positive anaerobic bacterium distributed in the oral cavity, with a potential to become pathogenic causing lung abscess. Due to the lack of specificity of symptoms and the difficulty in culture, the diagnosis of lung abscess associated with P. micra is delayed. It is essential to elucidate the clinical characteristics of lung abscess associated with P. micra.Methods: From January 2019 to July 2020, five patients with chronic lung abscess associated with P. micra diagnosed by pathological biopsy and metagenomic next-generation sequencing (mNGS) were analyzed in this retrospective study.Results: Among the five patients, four had a history of smoking, three had periodontitis, and two had a history of drinking. The average course of the disease was 6.5 months. High-density flake-like or mass shadows with irregular boundaries were observed in the chest computed tomography (CT) images of the five patients, and liquefactive necrosis was detected in the middle of the lesions; however, no gas-liquid plane or cavity was noted, making it difficult to distinguish a lung cancer. The pathological biopsy of the five patients showed chronic inflammation of lung tissue, and P. micra was detected by mNGS in the biopsy or bronchoalveolar lavage fluid samples. Two patients were treated with amoxicillin-clavulanate, two had metronidazole, and one had moxifloxacin. Among them, four recovered after receiving antibiotic treatment, and the remaining one underwent surgical resection due to poor antibiotic treatment effect.Conclusion: Chronic lung abscess associated with P. micra, common in elderly male smokers with poor oral hygiene, is often diagnosed in a delayed manner and misdiagnosed as lung cancer. The mNGS technology is beneficial to the rapid determination of P. micra.Keywords: Parvimonas micra, P. micra, lung abscess, metagenomic next-generation sequencing, mNGS

Keywords

• parvimonas micra (p. micra)
• lung abscess
• metagenomic next-generation sequencing (mngs)