VITEK MALDI-TOF MS技术在临床分离诺卡菌快速鉴定中的简易流程优化

目的 本研究利用基质辅助激光解吸电离飞行时间质谱-VITEK MALDI-TOF MS,对临床分离诺卡菌进行快速、准确、简易的菌种鉴定。方法 对46株临床分离的诺卡菌进行研究,以16S rRNA和gyrB基因测序结果为参考标准,探索VITEK MALDI-TOF MS技术在诺卡菌菌种鉴定程序中的关键步骤,优化鉴定流程。结果 46株诺卡菌共有43(93.5%)株可鉴定至种水平,45(97.8%)株可鉴定至属水平。对分离率最高的盖尔森基兴诺卡菌和鼻疽诺卡菌的鉴定率更是高达100.0%(22/22和7/7株)。结论 实验结果表明,VITEK MALDI-TOF MS技术可以实现对临床分离诺卡菌的快速、准确鉴定,简易鉴定流程为广泛应用于临床微生物实验室提供了重要基础保障。     

基于物种特异性PCR技术检测鼻疽诺卡菌和巴西诺卡菌的初步研究

目的 建立一种可以鉴别鼻疽诺卡菌和巴西诺卡菌的双重物种特异性PCR(species-specific Polymerase Chain Reaction,SS-PCR)诊断方法。方法 基于鼻疽诺卡菌和巴西诺卡菌物种特异基因NFA_41530和O3I_RS18895分别设计特异性引物,通过优化反应条件和体系,建立快速准确的双重SS-PCR。对95株鼻疽诺卡菌、13株巴西诺卡菌和42株非目标菌株进行扩增,分析该方法的特异性和灵敏度,并通过模拟痰样本验证方法的准确性,预估其在临床诊断的价值。结果 鼻疽诺卡菌和巴西诺卡菌质检分别扩增出一条清晰且单一的目标条带,其余42株非目标菌株均未扩增,表明该方法具有很好的特异性。该方法对鼻疽诺卡菌、巴西诺卡菌的检测下限分别为1.3×10⁴ copies/μL、2.4×10⁴ copies/μL,灵敏度较高。使用20个健康人的痰液模拟痰样本,检测符合率为100%。结论 基于NFA_41530和O3I_RS18895基因建立的双重SS-PCR方法特异性强、灵敏度较高,是一种可以同时鉴定鼻疽诺卡菌和巴西诺卡菌的简便、快速、可靠、经济的方法。     

星形诺卡菌肺部感染1例并文献复习

[摘要]?诺卡菌广泛分布于外界环境中,由其引起的化脓性肺部感染称为肺诺卡菌病。临床感染常见致病菌为星形诺卡菌。肺诺卡菌病缺乏特异性临床表现和影像学特征,目前尚无特异性的诊断指标,临床极易造成误诊、漏诊。诺卡菌的分离与培养为诊断该病的金标准。本文现对1例星形诺卡菌肺部感染病例进行分析,并结合文献复习,对该病的临床特征、影像学特点、实验室诊断及治疗进行探讨,为临床诊治该类疾病提供借鉴和参考。     

肺诺卡菌病4例报告并文献复习

目的 提高临床医生对肺诺卡菌病的的认识.方法 分析4例肺诺卡菌病的临床特点,并复习相关文献.结果 4例肺诺卡菌病患者2例有免疫性疾病并服用免疫抑制剂,4例均有咳嗽咳痰和发热,3例为午后发热.肺部影像学表现4例肺实变影,3例大小不等的结节影/肿块影并可见空洞.病原学检查标本多种.磺胺治疗效果较好.结论 肺诺卡菌病缺乏特异性临床表现,肺部多发结节影/肿块影并空洞形成是其影像学特点,磺胺是主要治疗药物.     

播散性皮疽诺卡菌病误诊肺结核一例

<正>皮疽诺卡菌,又名鼻疽诺卡菌, 1888年首次从牛的皮疽病中分离,存在自然环境中。主要引起呼吸系统疾病、皮肤感染及全身播散性疾病^[1]。皮疽诺卡菌为机会致病菌,发病率较低,临床症状无特异性,且诺卡菌与分枝杆菌具有相似的染色特征和形态特征,临床上常常将诺卡菌病误诊为结核分枝杆菌感染^[2]。笔者对浙江省中西医结合医院结核病诊疗中心收治的1例皮疽诺卡菌感染患者报告如下。临床资料患者,女,56岁,因“咳嗽咳痰1个月,左腋下红肿20 d,     

诺卡菌病的诊治进展

诺卡菌病是由诺卡菌引起的化脓性感染。诺卡菌可通过呼吸道吸入感染肺部,同时可血行播散至其他器官形成脓肿,尤其引起颅内感染。免疫抑制个体是诺卡菌病的易感人群,该病临床表现缺乏特异性,早期诊断困难,治疗时间长。本文就诺卡菌病的危险因素、临床表现、影像学表现、药物治疗进展进行综述,为其临床治疗提供参考。     

1例单增李斯特菌误诊病例分析并文献复习

目的 探讨1 例单增李斯特菌病的诊疗过程及误诊原因,降低误诊率。方法 回顾性分析先后误诊为视神经脊髓炎、病毒性脑膜炎的单增李斯特菌脑膜炎患者的诊疗过程及误诊原因。结果 患者主要表现为肢体麻木、乏力、反复发热、意识障碍、言语不清等。单增李斯特菌性脑膜炎累及脊髓患者临床表现具有误导性。患者经青霉素联合复方磺胺甲噁唑治疗好转出院,遗留神经系统后遗症。结论 临床医生应提高对单增李斯特菌感染疾病的警惕性,加强对相关知识的了解,提高诊治水平,避免误诊误治。     

诺卡菌病24例的临床分析

目的:分析诺卡菌病患者的临床特点,为提高诺卡菌病的诊治水平提供帮助。方法:收集2016年5月至2020年10月长沙中南大学湘雅医院收治的24例诺卡菌病患者的临床资料,回顾性分析其临床特点、实验室检查、影像学表现、诊治与转归。结果:24例诺卡菌病患者中,男18例(75.0%),中位年龄为54.5岁。23例患者合并基础疾病...     

SLE并播散性诺卡菌感染一例

诺卡菌病是由诺卡菌感染所致的急慢性化脓性疾病,经呼吸道或直接感染皮肤造成内脏及皮肤严重感染,人与人之间不传播.诺卡菌感染为少见病,60％的病例发生于机体抵抗力低下人群[1],随着器官移植、肿瘤、艾滋病感染者的增多以及对自身免疫性疾病的进一步认识和治疗,诺卡菌感染病例逐年增多,但因其临床及影像学表现无特异性,且医务人员对此病认识不足,容易造成漏诊或误诊.我们曾接诊并治疗1例系统性红斑狼疮(SLE)患者开始拟诊为播散性结核病后证实为全身性诺卡菌感染.现报道如下.     

肺结核合并诺卡菌病1例报告

<正>诺卡菌（Nocardia）广泛分布在土壤、水和有机质中,属需氧放线菌属,是一种呈分枝、串珠或丝状的杆菌,弱抗酸染色阳性,革兰染色阳性,可经呼吸道、血液、皮肤侵入人体,引起局部及全身系统感染,其中肺部感染最常见。关于诺卡菌病的治疗,目前尚无指南规范,现将南昌大学第一附属医院呼吸科收治的1例肺结核合并系统受累的诺卡菌病（累及肺、脑）进行总结分析。     

Disseminated nocardiosis due to unusual species: two case reports

Pulmonary nocardiosis is the major clinical manifestation of human nocardiosis and disseminated infection can be seen in immunocompromised patients. N. asteroides is the predominant pathogen associated with disseminated diseases. We report 2 cases of pulmonary nocardiosis admitted with disseminated infection, caused by rare species of Nocardia: Nocardia transvalensis and Nocardia cyriacigeorgica.     

Pulmonary nocardiosis re-visited: experience of 35 patients at diagnosis

Pulmonary infection by Nocardia is an uncommon opportunistic infection in humans. Thirty-five patients with pulmonary nocardiosis were identified in two tertiary referral hospitals. A retrospective review of the patient characteristics, clinical and laboratory features including antimicrobial susceptibility at diagnosis was carried out. Radiological features derived from chest radiographs and CT scans were also documented. In our population, the predominant risk factors were immuno-compromised state, corticosteroid therapy, and underlying pulmonary pathology. The presenting features were similar to those previously described but disseminated infection was not common. The radiological changes were diverse and non-specific. Nocardia asteroides was the commonest species. Most Nocardia isolates were susceptible to imipenem, ceftriaxone, amikacin, and cotrimoxazole. Co-existing microbial agents are common and reflect the underlying complex disorders.     

A case of liver nocardiosis associated with Crohn's disease while treating infliximab

A 23-year-old man, complaining of chronic diarrhea, was given a diagnosis of Crohn's disease. He responded well to steroid therapy and infliximab administration. However, high fever appeared on the 28th day of hospitalization, and CT scan revealed multiple liver abscesses. Gram-positive branched rods were harvested by ultrasonography guided puncture examination. As Nocardia infection was suspected, sulfamethoxazole-trimethoprim was started immediately, and his clinical course improved dramatically. Afterwards, Nocardia farcinica was isolated from the culture of the liver abscess. This case is the first report of liver nocardiosis associated with Crohn's disease. Generally, Nocardia infection can be successfully treated by sulfamethoxazole-trimethoprim therapy. Liver nocardiosis is very rare but could be an important complication for patients with Crohn's disease.     

诺卡菌感染患者44例的临床特征及其预后

目的:了解诺卡菌感染患者的临床特征及预后。方法:回顾性分析2013年1月至2019年7月于上海复旦大学附属华山医院感染科诊治的44例诺卡菌感染患者的临床资料,包括一般临床表现、基础疾病、使用糖皮质激素情况、实验室检查指标(包括血常规、降钙素原、C反应蛋白、淋巴细胞亚群等)、影像学改变、菌种鉴定、治疗与转归。根据感染类型分为单纯肺部感染组、肺外单个器官感染组和播散性感染组。两组间比较采用曼-惠特尼U检验,多组间比较采用Kruskal-Wallis H检验。结果:44例诺卡菌感染患者中,14例为单纯肺部感染,17例为肺外单个器官感染(其中中枢神经系统感染9例,皮肤软组织感染6例,腹腔脓肿1例,尿路感染1例),13例为播散性感染(其中血流感染4例,中枢神经系统合并肺部或皮肤软组织感染6例,肺部合并皮肤软组织感染3例)。34例患者合并基础疾病,27例患者正在使用糖皮质激素或免疫抑制剂。11例单纯肺部感染患者的主要表现为咳嗽、咳痰;肺外单个器官感染和播散性感染患者的主要表现为发热。诺卡菌菌种以巴西、星形、鼻疽诺卡菌为主。白细胞计数和中性粒细胞比例正常或轻度升高42例,血小板计数正常或轻度下降41例,红细胞沉降率升高19例,降钙素原升高21例,C反应蛋白升高34例,铁蛋白升高18例。34例患者检测了淋巴细胞亚群,其中15例CD4+T淋巴细胞下降,14例CD8+T淋巴细胞升高,7例B淋巴细胞升高,7例B淋巴细胞下降,8例自然杀伤细胞下降。单纯肺部诺卡菌感染患者血红蛋白高于肺外单个器官感染患者,差异有统计学意义(U=0.095,P=0.025)。影像学表现以脓肿、炎症渗出为主。治愈或好转40例,1例仍在治疗,死亡3例。结论:累及各部位的诺卡菌病的临床表现无特异性,经过规范治疗可降低诺卡菌病的病死率。     

Pulmonary nocardiosis: risk factors, clinical features, diagnosis and prognosis

PURPOSE OF REVIEW: Pulmonary infection by Nocardia spp. has been recognized for the past 100 years. The number of cases of pulmonary nocardiosis reported in the literature is increasing, and in some cases, a diagnosis is reached even postmortem. This increase is partly due to the growing number of patients with depressed cellular immunity. The diagnosis of this infection, which has a high rate of mortality, is usually delayed, due to a nonspecific clinical-radiological presentation and the difficulties in cultivating the bacteria. This review analyzes the current situation, in order to better understand this infection and enhance awareness and clinical suspicion that would lead to further specific microbiological studies and treatment. RECENT FINDINGS: The number of case series in the literature is increasing. This development may be due to an absolute increase in the number of immunocompromised patients, but also to improvements in laboratory techniques and molecular methods to detect nocardiosis. SUMMARY: It is important to keep in mind, and suspect the presence of pulmonary nocardiosis in the immunodepressed patients with clinical pulmonary infection. Furthermore, the laboratory should be notified when Nocardia is suspected in a clinical specimen so that measures can be taken to optimize recognition and recovery of the organism.     

Nocardial infections: report of 22 cases

Twenty-two cases of nocardial infections were diagnosed in our city between 1977- 1998. All patients whose clinical specimens showed Nocardia spp. at Gram stain, which were further confirmed by culture, were selected to be included in the study. Data from patients who were cured were compared with those from patients who died by statistical tests using EPIINFO version 6.04 software. Six isolates were identified as Nocardia asteroides complex, one as Nocardia asteroides sensu stricto and other as Nocardia brasiliensis. We had 17 cases of lung nocardiosis, being one out of them also a systemic disease. Other four cases of systemic nocardiosis were diagnosed: nocardial brain abscesses (one); nocardiosis of the jejunum (one); multiple cutaneous abscesses (one); and a case of infective nocardial endocarditis of prosthetic aortic valve. One patient had a mycetoma by N. brasiliensis. Fifteen (68.2%) out of 22 patients were immunosuppressed, being most (93.3%) by high-doses corticotherapy. Mortality by nocardial infection was 41%; mortality of systemic nocardiosis was 60%. Nocardiosis has a bad prognosis in immunosuppressed patients and also in non-immunosuppressed patients if the diagnosis is delayed. We propose that the delay in diagnosis should be examined in larger series to document its influence in the prognosis of the disease.     

Rapid diagnosis of nocardiosis with an enzyme immunoassay

Diagnosis of nocardiosis is often delayed because of the frequently nonspecific nature of the illness and because of the long incubation period required to isolate the organism in the microbiology laboratory. Past experience with serological methods for diagnosing nocardiosis have met with little success, primarily because there was no suitable antigen. Using a previously identified Nocardia asteroides-specific protein, we developed an enzyme immunoassay for the rapid diagnosis of nocardiosis. We evaluated sera from 22 patients with nocardiosis, 83 hospitalized controls, and 21 patients with tuberculosis. Twenty (91%) of the sera from patients with nocardiosis had titers of antibody greater than or equal to 1:256, whereas all of the sera from controls and from patients with tuberculosis had titers less than 1:256. This assay represents a highly sensitive and specific serodiagnostic tool for evaluating patients with possible nocardiosis.     

A case report of pulmonary nocardiosis successfully treated with a combination of sulfamethoxazole-trimethoprim (ST) and sparfloxacin]

We encountered a case of pulmonary nocardiosis that responded dramatically to combined ST and sparfloxacin treatment. A 55-year-old woman presented with fever, cough and yellowish sputum. She had been under treatment with oral prednisolone (15 mg per day) since July 1997 after a diagnosis of Evans syndrome. A high fever of 39.8 degrees C was noted on January 30, 1998. The patient was hospitalized for bloody sputum, bilateral hypochondriac pain and evidence of infiltrative opacities in the left lower lobe on chest radiography. Bacterial pneumonia was suspected, and she was treated with piperacillin, but her clinical symptoms did not improve. Sputum culture and serologic examination failed to lead to a definitive diagnosis. Nocardia farcinica was isolated by culturing tissue obtained by CT-guided transcutaneous pulmonary biopsy, leading to a diagnosis of pulmonary nocardiosis. The results of an MIC test for antimicrobial agents led to treatment with a combination of ST and sparfloxacin, and the clinical symptoms improved. These clinical observations suggest that, when pneumonia is diagnosed in patients who have been receiving oral steroids for a prolonged period, pulmonary nocardiosis should be considered in the differential diagnosis to enable selection of appropriate antimicrobial agents.     

Pulmonary Nocardia otitidis-caviarum infection in a patient with Cushing's disease]

While Nocardial infections are being diagnosed with increasing frequency, infection with Nocardia otitidiscaviarum remains relatively uncommon. We report a case of pulmonary Nocardia otitidis-caviarum infection in a 35-year-old man with Cushing's disease. This work describes the first case of nocardiosis in Japan caused by Nocardia otitidis-caviarum in Cushing's disease. The patient was admitted to our department because of edema. A diagnosis of Cushing's disease was made on the basis of elevated serum levels of cortisol and adrenocorticotropic hormone (ACTH) and pituitary adenoma was found in a cranial CT scan. One month after admission, chest radiographs showed a large bilateral mass on the lung fields. Nocardia otitidis-caviarum was isolated from the sputum. The patient responded poorly to intravenous PAPM/BP, but later improved after treatment with trimethoprim-sulfamethoxazole, but he died of heart failure and respiratory failure after the initiation of this therapy. This case demonstrated that nocardiosis must be considered in differential diagnosis as an opportunistic infection.     

Molecular diagnosis of fatal Nocardia farcinica pneumonia in an HIV-negative patient

Nocardiosis is a rare and potentially life-threatening infection caused by several species of the Nocardia genus. Most cases occur in immunocompromised patients, and a delay in establishing the diagnosis is common due to the non-specific clinical presentations and the difficulty in cultivating Nocardia. Although the majority of pulmonary nocardiosis cases are caused by Nocardia asteroides, cases of human infection due to N. farcinica are increasingly diagnosed due to recent developments in taxonomy and diagnostic methods. N. farcinica is a separate species from N. asteroides and appears to be more virulent and resistant to antibiotics. Herein, we describe the case of a 65-year-old HIV-negative immunocompromised patient with a fulminant bilateral pulmonary nocardiosis while on empirical treatment with trimethoprim/sulfamethoxazole and imipenem. Post-mortem diagnosis of N. farcinica infection was performed by means of DNA amplification and sequencing of the 65-kDa bacterial heat shock protein.