PDF(Pubmed)
Abstract：
Mycobacterium porcinum is a nontuberculous mycobacteria (NTM) recently identified to cause human infection. Correct speciation of NTMs can be difficult and result in misdiagnosis and delayed treatment. Because of the paucity of the literature, there is a lack of awareness of the possibility of serious infections caused by M. porcinum. Although severe infections tend to occur in individuals with certain risk factors, the primary being an immunocompromised state, our case illustrates that it can also be possible in non-severely immunocompromised individuals. A 65-year-old male with a medical history of diabetes mellitus (DM), end-stage renal disease (ESRD) on hemodialysis (HD), congestive heart failure (CHF), and chronic obstructive pulmonary disease (COPD) was admitted to the emergency room due to a laceration on his right lower leg following a fall. He reported shortness of breath but denied other respiratory symptoms. On examination, he showed signs of infection and increased oxygen requirement compared to baseline. Blood culture was positive for acid-fast bacilli (AFB), initially reported as M. avium complex (MAC) and later confirmed as M. porcinum through gene sequencing and morphology analysis. Interval blood cultures taken a week later confirmed true M. porcinum bacteremia. Treatment initially involved intravenous antibiotics- imipenem and ciprofloxacin before transitioning to oral linezolid and ciprofloxacin based on sensitivities. Following 10 days of antibiotic therapy, subsequent blood cultures returned negative, and treatment with oral antibiotics was advised, with continued outpatient follow-up with infectious disease in two weeks. M. porcinum, typically considered a contaminant in healthy individuals, was identified as the causative agent of a disseminated infection in a non-severely immunocompromised patient. This case underscores the importance of accurately identifying the specific mycobacterial species, confirming true infection, and conducting antibiotic susceptibility testing due to the distinct antibiotic susceptibility profile of M. porcinum compared to other NTM like MAC.
摘要：
猪分枝杆菌是一种非结核分枝杆菌（NTM），最近被发现会引起人类感染。NTM的正确形成可能很困难，并导致误诊和延迟治疗。由于文学的匮乏，对由M.porcinum引起的严重感染的可能性缺乏认识。尽管严重感染往往发生在具有某些危险因素的个体中，主要是免疫受损状态，我们的案例表明,在非严重免疫功能低下的个体中也可能出现这种情况.一名65岁男性，有糖尿病（DM）病史，血液透析（HD）的终末期肾病（ESRD），充血性心力衰竭（CHF），慢性阻塞性肺疾病（COPD）因跌倒后右小腿裂伤而被送往急诊室。他报告呼吸急促，但否认其他呼吸道症状。在检查中，与基线相比，他显示出感染迹象和增加的需氧量。血培养显示抗酸杆菌(AFB)阳性,最初报道为M.avium复合体（MAC），后来通过基因测序和形态学分析证实为M.porcinum。一周后进行的间隔血液培养证实了真正的猪分枝杆菌菌血症。治疗最初涉及静脉注射抗生素-亚胺培南和环丙沙星，然后根据敏感性过渡到口服利奈唑胺和环丙沙星。抗生素治疗10天后，随后的血培养返回阴性，建议口服抗生素治疗，在两周内继续门诊随访传染病。M.porcinum,通常被认为是健康个体的污染物，被确定为非严重免疫受损患者的播散性感染的病原体。这一案例强调了准确识别特定分枝杆菌物种的重要性，确认真正的感染，并进行抗生素敏感性测试，因为与其他NTM如MAC相比，分枝杆菌的抗生素敏感性曲线不同。
