Pathogen Characteristics And Risk Factors Analysis Of Multi-drug Resistant Bacteria Infection In Patients With Severe Pneumonia

Objective:Analyze the pathogenic characteristics and risk factors of multi-drug resistant bacteria infection in patients with severe pneumonia in our hospital,so as to provide the basis for doctors to evaluate the risk factor of multi-drug resistant bacteria infection when they face the patients with severe pneumonia and reasonably select antibiotics.Methods:(1)Collect the multi-drug resistant bacterial strains with specific drug sensitivity test that are isolated from airway blood pleural effusion from the patients with severe pneumonia in our hospital from January 2017 to July 2019,and remove the data of bacterial strains with the same drug sensitivity in the same part of the same patient.Statistically analyze the distribution of pathogenic detection types,the distribution and composition of pathogenic bacteria,the distribution of the samples’ sources and the result of drug sensitivity test.(2)Collect the clinical material of patients who are diagnosed as severe pneumonia with bacterial infection indicated by etiological examination in our hospital from January 2017 to July 2019,make statistics of clinical material including the patients’ sex,age,smoking history,alcohol history,types of basic diseases,usage of hormone,usage of proton pump inhibition,time and types of antibacterial drugs used within 30 days before infection,various invasive operations and admission to ICU,so as to analyze whether it might be a risk factor for multi-drug resistant bacteria infection.Results:(1)The detection type distribution of multi-drug resistant bacteria in severe pneumonia patients: There are 558 bacteria strains isolated from all patients with severe pneumonia in our hospital from January 2017 to July 2019.The multiple-drug resistant bacteria accounts for 49.1% of all positive samples.Among the detected multi-drug resistant bacteria,pathogenic bacteria account for 71.53%,most of them are Gram-negative bacteria.(2)In the etiology of all severe pneumonia patients in our hospital from January 2017 to July 2019,the top five bacteria strains are Acinetobacter baumannii(23.66%),Klebsiella pneumoniae(16.85%),Pseudomonas aeruginosa(16.67%),Staphylococcus aureus(13.08%)and Escherichia coli(6.81%).There are 196 bacteria strains of multi-drug resistant bacteria in severe pneumonia patients,the top five are Acinetobacter baumannii(34.18%),Klebsiella pneumoniae(24.49%),Staphylococcus aureus(18.88%),Pseudomonas aeruginosa(16.84%)and Escherichia coli(2.04%).(3)Specimen source distribution of the main multi-drug resistant bacteria in severe pneumonia patients: respiratory tract is the most common source of the top five multi-drug resistant bacteria samples of all severe pneumonia patients in our hospital from January 2017 to July 2019,followed by the source of blood and pleural effusion.Among the top five multi-drug resistant bacteria,the highest isolation rate is still in the respiratory tract.(4)The drug sensitivity test result of main multi-drug resistance bacteria in severe pneumonia patients: all Acinetobacter baumannii are resistant to gentamicin,meropenem and imipenem,and the resistance rate to cefoperazone sulbactam and amikacin is over 90%.The result shows that fifty-six bacteria strains are sensitive to polymyxin E;thirty strains are sensitive to tigecycline,the drug resistance rate is23.33%;and five strains are not resistance to minocycline.All multi-drug resistant Klebsiella pneumoniae are resistant to cefepime and ampicillin sulbactam,the drug resistance rates of piperacillin tazobactam is 97.92%,the rate of ceftazidime and cefoperazone sulbactam is 95.83%,imipenem,meropenem and amikacin are 87.50%,85.42% and 64.58% respectively;Four strains are supplemented with tigecycline and one strain is supplemented polymyxin E sensitivity test,we can see all of them are sensitive to tigecycline and polymyxin E.The rate of all the multi-resistant pseudomonas aeruginosa that resistant to meropenem and piperacillin are 100%,more than 90% resistant to piperacillin tazobactam,ceftazidime and levofloxacin,and resistant to cefoperazone sulbactam,aztreonam,imipenem and Amikacin to varying degrees.Five bacteria strains are supplemented with polymyxin E sensitivity test,and all of them are sensitive to polymyxin E in the test.Among Gram-positive bacteria,all methicillin-resistant Staphylococcus aureus are equally sensitive to vancomycin,linezolid,compound minophen and rifampicin,while four strains are sensitive to teicoplanin,and the result shows that all the tested strains are sensitive.(5)In the single factor analysis of multiple drug resistant bacteria infection in patients with severe pneumonia,compare the factors of age,gender,chronic obstructive pulmonary disease,malignant tumor,proton pump inhibitor,deep vein catheter,indwelling catheter,indwelling gastric tube,invasive mechanical ventilation,admission to ICU,the use of time and types of antibiotics in the last 30 days before infection in the multi-drug resistant bacteria group and non multi-drug resistant bacteria group,the result is statistically significant(P < 0.05).Include the factors in the binary logistic regression analysis,and it is found that chronic obstructive pulmonary disease,indwelling catheter,invasive mechanical ventilation,admission to ICU,the use of time(≥ 15 days)of antibiotics in the last 30 days before infection,and use type(≥ 3 kinds)of antibiotics in the last 30 days before infection are the independent risk factors of multiple-drug resistant bacteria infection in severe pneumonia patients.Conclusions:(1)Gram-negative bacteria are the main multi-drug resistant bacteria in patients with severe pneumonia,Acinetobacter baumannii is the main multi-drug resistant Gram-negative bacteria and Staphylococcus aureus is the main multi-drug resistant Gram-positive bacteria.(2)Gram negative bacteria with multi-drug resistance have higher resistance rate to carbapenems,cefoperazone sulbactam and piperacillin tazobactam,but they still have good sensitivity to polymyxin E and tigecycline(except for Pseudomonas aeruginosa).Methicillin-resistant Staphylococcus aureus of Gram-positive bacteria are not resistant to vancomycin,linezolid and teicoplanin.(3)Chronic obstructive pulmonary disease,indwelling catheter,invasive mechanical ventilation,addmission to ICU,the use of time of antibiotics(≥ 15 days)in the last 30 days before infection,and use types of antibiotics(≥ 3 kinds)in the last 30 days before infection are the independent factors of multiple drug resistant bacteria infection in patients with severe pneumonia.Doctors should evaluate the risk of multiple drug resistant bacteria infection in patients with severe pneumonia in time,and reasonably select antibiotics in accordance with the epidemic situation and drug sensitivity characteristics of multiple drug resistant pathogenic bacteria in our hospital,so as to reduce the production of drug resistant bacteria.