Analysis Of Drug Resistance And Clinical Characteristics Of Methicillin-resistant Staphylococcus Aureus Pneumonia

Objective: To retrospectively analyze the drug resistance and clinical characteristics of MRSA pneumonia patients to common antibiotics,and provide powerful countermeasures for better treatment and prevention of pneumonia caused by Staphylococcus aureus.Methods:1.Statistics of Staphylococcus aureus isolated from sputum culture and bronchoalveolar lavage fluid samples of inpatients in our hospital in recent 4 years and clinically diagnosed as pneumonia.2.Retrospective analysis of the resistance rate of MRSA pneumonia strains to common antibiotics and the MIC value of vancomycin and linezolid in our hospital in the past 4 years.3.Compare the MRSA group and the MSSA group,including the general data,the length of hospital stay before the positive isolation of pathogenic bacteria,basic diseases,invasive operations,chest imaging,initial empirical antibiotic selection,and the results of relevant laboratory tests.4.According to the source of MRSA strains,patients with community-acquired pneumonia,hospital-acquired pneumonia and ICU pneumonia were divided.The clinical data of three groups of patients were collected by the above method.Results: In the past four years,243 strains of Staphylococcus aureus were diagnosed as pneumonia by clinical diagnosis in our hospital,including 123 strains of MRSA,accounting for 50.62%.The detection rate of MRSA increased in 2018,but the overall trend was downward(53.19% in 2017,62.16% in 2018,44.23% in 2019,and 41.43% in 2020).The strains were mainly from the Department of Critical Medicine,and the isolation rate of Staphylococcus aureus(62.55%)and the detection rate of MRSA(59.35%)were significantly higher than those of other departments.The proportion of Staphylococcus aureus pneumonia and MRSA pneumonia in patients over 75 years old was the highest.MRSA strain has a high sensitivity rate to quinolones,clindamycin and erythromycin,and a high sensitivity rate to cotrimoxazole,gentamicin and furantoin.The insensitivity rate of MRSA to antibacterial drugs was generally higher than that of MSSA group.In the past four years,there have been non-sensitive strains of teicoplanin,linezolidine and vancomycin,accounting for about 2%,and no non-sensitive strains of tegacyclin,quinupatine/dafopratine and rifampicin have been found.The clinical data of the two groups of patients were analyzed.The results of univariate analysis showed that the previous history of surgery,blood transfusion,pulmonary infection within 6 months before infection,albumin ≤ 30g/L,intravenous catheterization and initial empirical antibiotic selection were all related to the infection of MRSA pneumonia.Single lung infiltration was more common in MSSA pneumonia,but MRSA pneumonia often had higher inflammatory reaction.Multivariate regression analysis showed that age,blood transfusion history and pulmonary infection history in the past 6 months were independent risk factors for MRSA pneumonia infection.The clinical data of patients with CAP(n=15),HAP(n=34)and ICU pneumonia(n=75)were analyzed.The results of univariate analysis showed that age,smoking history,complicated cerebrovascular disease,average length of hospital stay,length of hospital stay before positive pathogenic bacteria isolation,mechanical ventilation,venous catheterization and antibiotic selection would affect CAP Infection of HAP and ICU pneumonia.Multiple logistic regression analysis showed that in the comparison of the three groups,the use of cephalosporins alone was an independent risk factor for ICU pneumonia,and the inflammation index of ICU pneumonia was higher than that of HAP pneumonia.Smoking history is an independent risk factor for HAP patients.Conclusion: The overall MRSA detection rate has shown a downward trend in the past four years,especially in intensive care units and elderly patients.Teicoplanin,linezolidine and vancomycin insensitive strains have emerged in recent years.Multiple factors can increase MRSA pulmonary infection,among which age,blood transfusion history,and pulmonary infection history in the past 6 months are independent risk factors for MRSA pneumonia.The infection status of CAP,HAP,and ICU pneumonia is influenced by multiple factors.In the comparison of the three groups,the use of cephalosporins alone is an independent risk factor for ICU pneumonia.ICU pneumonia has higher inflammation indicators than HAP pneumonia,and smoking history is an independent risk factor for HAP patients.