Xiao Yan, Wang Hongwei, Tian Tingting, Zheng Juanjuan, Liu Mengyang, Wang Qing, Li Jing
Department of Clinical Laboratory, The Affiliated Hospital of Qingdao University, Qingdao, China.
Blood Transfusion Department, The Qilu Hospital of Shandong University Dezhou Hospital, Dezhou Shandong Province, China.
Medicine (Baltimore). 2024 Dec 6;103(49):e40054. doi: 10.1097/MD.0000000000040054.
Nocardia is a conditionally pathogenic bacterium found in the natural environment and is an aerobic bacterium, which causes severe pneumonia relatively rarely. The diagnosis of primary Nocardia infection is always made late due to the nonspecific clinical presentation of patients with Nocardia infection and the time required for Nocardia culture. Due to its rarity and nonspecific clinical presentation, patient survival is often compromised due to misdiagnosis.
A 53-year-old woman with autoimmune cirrhosis was treated with glucocorticoids. Three and a half months later the patient developed fever, nausea, cough and sputum, treated with empirical antibiotics, and the patient occurred type I respiratory failure.
Nocardia was identified by sputum culture micromorphology and Meriere matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF).
The patient was treated with trimethoprim-sulfamethoxazole (TMZ), and the patient's oxygen saturation recovered significantly.
The patient's overall recovery was slow due to decreased albumin (ALB) and increased procalcitonin (PCT) caused by the patient's cirrhosis. Due to economic reasons, the family gave up, asked to be discharged.
In our report, patients with underlying disease are immunocompromised and at increased risk of infection with conditionally pathogenic bacteria. Nocardia has no specific presentation and is often overlooked clinically. Treatment of these patients should not be limited to common bacteria or viruses, but should consider rare opportunistic pathogens, and we need to be vigilant for Nocardia infections and timely use of sulfonamide antibiotics to reduce mortality.
诺卡菌是一种存在于自然环境中的条件致病菌，属于需氧菌，相对较少引起严重肺炎。由于诺卡菌感染患者临床表现不具特异性以及诺卡菌培养所需时间，原发性诺卡菌感染的诊断往往较晚。因其罕见性和临床表现不具特异性，患者常因误诊而影响生存。
一名53岁自身免疫性肝硬化女性接受糖皮质激素治疗。三个半月后患者出现发热、恶心、咳嗽咳痰，接受经验性抗生素治疗，随后发生I型呼吸衰竭。
通过痰培养微观形态学及梅里埃基质辅助激光解吸电离飞行时间质谱（MALDI - TOF）鉴定出诺卡菌。
患者接受甲氧苄啶 - 磺胺甲恶唑（TMZ）治疗，氧饱和度明显恢复。
由于患者肝硬化导致白蛋白（ALB）降低、降钙素原（PCT）升高，患者总体恢复缓慢。因经济原因，家属放弃治疗，要求出院。
在我们的报告中，有基础疾病的患者免疫功能低下，感染条件致病菌的风险增加。诺卡菌无特异性表现，临床常被忽视。对这些患者的治疗不应局限于常见细菌或病毒，而应考虑罕见的机会性病原体，我们需警惕诺卡菌感染并及时使用磺胺类抗生素以降低死亡率。
