Research On Clinical Diagnosis And Treatment Of Nocardiosis

Objective: Nocardiosis is easily misdiagnosed as lung cancer,tuberculosis,brain tumor,sporotrichosis,cellulitis,erythema nodosum,atypical mycobacterium,etc.Misdiagnosis will delay the time of treatment,when bacteria enter into the blood,it will cause systemic disseminated infection,make the disease rapidly worsen,and even cause death.There is no unified,standard,reliable,rapid and accurate diagnosis and treatment method in the world at present.Through the summary of clinical manifestations,bacterial culture,DNA extraction and sequencing,and clinical treatment of patients,this paper aims to propose a rapid diagnosis and treatment method of nocardiosis,which provides a new way for clinicians to diagnose nocardiosis,and also provides clinical experience and theoretical basis for the rapid treatment of nocardiosis.It is expected to further promote the in-depth diagnosis and treatment of nocardiosis development.Methods:(1)The clinical data of nocardiosis patients in recent 3 years were collected.There were 6 cases of skin infection,10 cases of lung infection and 3 cases of disseminated infection.Among the 19 patients,13 were infected with lung,7 with skin,1 with brain and 1 with pleura.There were 3 cases of disseminated infection,1 case of lung and brain infection,1 case of lung and skin infection,1 case of lung and pleura infection.19 patients,16 with basic diseases and 3 without basic diseases.(2)The non polluted pus,sputum,puncture fluid and bronchoalveolar lavage fluid were extracted from the skin lesions of the patients for Gram staining,weak acid fast staining and culture.The cultured colonies were detected and analyzed by matrix assisted laser desorption ionization time-flight mass spectrometry.(3)Extract the colony,complete the DNA extraction of Nocardia according to the technical requirements of the kit,and detect the DNA concentration and purity.(4)Applied 16 S r RNA sequencing analysis of the extracted genes.(5)Nocardiosis was diagnosed and treated.Penicillin,cephalosporins,quinolones,compound sulfamethoxazole tablets and other drugs were given.For patients with Nocardia infection of lung,brain and dissemination,2-3 kinds of sensitive drugs were selected for combined treatment,with a course of 6-12 months.For patients with Nocardia infection of skin and no chronic basic diseases,1-2 kinds of sensitive drugs were selected for treatment,with a course of 2-3 months.Local abscess should be cut and drained;local fester should be treated with debridement and dressing change.(6)Through the comprehensive analysis of domestic and foreign literature,the etiology,pathogenesis,clinical manifestations,laboratory examination,differential diagnosis and clinical treatment of nocardiosis were summarized.The process of diagnosis and treatment was recorded.The etiology,pathogenesis,clinical manifestation,laboratory examination,differential diagnosis and clinical treatment of nocardiosis were summarized.The comprehensive analysis was carried out in combination with domestic and foreign literature.To summarize the accurate diagnosis and treatment of nocardiosis.Results:(1)Gram staining and weak acid-fast staining were positive in pus smears.(2)A large number of white,dry and irregular gypsum powder-like colonies were observed on the blood plate in the culture of pus at the lesion.Nocardia was identified by mass spectrometry analysis.(3)After DNA extraction and 16 S r RNA sequence analysis,Nocardia was confirmed by comparing with gene library map.(4)Patients were given amoxicillin and clavulanate potassium intravenous drip and compound sulfamethoxazole tablets orally.Among the 19 patients,5 cases of skin infection were cured in 2-3 months,11 cases of infection with basic diseases were improved,and 3 cases died(2 cases died in our hospital during hospitalization,1 case was discharged from our hospital after treatment and died in the local hospital one week later,the conclusion given by the local hospital was myocardial infarction).Conclusion:(1)Nocardiosis is easily misdiagnosed only according to clinical manifestations.Delayed treatment will lead to aggravation of the disease and death in serious cases.(2)The combined diagnosis method proposed in this paper based on Gram stain,weak acid fast stain,mass spectrum analysis of pus culture and molecular biological analysis is feasible and can be applied in clinical diagnosis.(3)The combination of intravenous drip,oral antibiotics and local symptomatic rapid treatment is feasible and can be used as a reference for clinical treatment.