Analysis Of Pathogen Distribution And Drug Resistance Of Secondary Infection In Adult Patients With Severe And Extra Severe Burns

Background and objective: infection is the most common complication in patients with severe and extra severe burns,and it is also one of the important c auses of death.The application of antibiotics is an important means of anti-infe ctive therapy.With the high screening pressure of broad-spectrum and high-effi ciency antimicrobial agents,pathogens mutate rapidly and the drug resistance s pectrum becomes wider and wider.The emergence of multiple drug-resistant st rains brings severe challenges to anti-infective treatment and hospital preventio n and control.Based on this,to investigate the nosocomial infection(Nosocomi alinfection,NI)of adult patients with severe and extra severe burns in the depart ment of burn plastic surgery in our hospital from 2015 to 2021,to explore the r elated infection factors,to study the detection of pathogenic bacteria,the charac teristics of drug resistance and the effect on prognosis in patients with different degrees of burn,and to put forward the corresponding measures for the control of nosocomial infection.With a view to providing data support for clinical stan dardized use of antibiotics,control of drug-resistant strains,management of nos ocomial infection and disinfection control.Methods:(1)The clinical data of adult patients with severe burn in the Department of Burn and plastic surgery of Zibo Occupational Disease Prevention and treatme nt Hospital from 2015 to 2021 were collected.(2)According to the diagnostic criteria of severe and extra severe burns,the patients were divided into two groups according to the burn area TBSA(30%-50%;50%).The distribution and drug resistance of pathogenic bacteria were ob served between the two groups.(3)The measurement data accorded with the normal distribution by t-test,n ot with the normal distribution by rank sum test,and the counting data by χ 2 te st.Infection was regarded as a binary scalar.The influence of multivariable on i nfection was analyzed by binary Logistic regression,and the distribution trend of pathogens was analyzed by curve estimation model.There was significant di fference between the two groups(P < 0.05).Results:(1)There were 238 burn patients who met the inclusion criteria of this stud y,including 179 males and 59 females.There were 179 cases(75.2%)of flame burn,the age was(46.66 ±16.23)years,and the burn area was(46.46 ±16.08)%.There was no sexual difference in burn age and burn cause between men and w omen(P < 0.05).(2)Burn area,tracheotomy,types of antimicrobials and age were independe nt risk factors for nosocomial infection in adult patients with severe and extra s evere burns.The ability to predict nosocomial infection by the combination of t he four indexes(AUC=0.892)was better than that of single item.(3)There was a significant difference in the distribution of pathogenic bact eria between adult severe burn patients and extra severe burn patients in our ho spital.Staphylococcus aureus was the highest in 30%～50%TBSA group(21.3%),and Pseudomonas aeruginosa was the highest in 50% group(32.1%).No Staphylococcus aureus resistant to vancomycin and linezolid was detected in bo th groups.(4)The drug resistance of Staphylococcus aureus to quinolones,macrolipi ds,sulfamethoxazole and rifampicin in 50%TBSA group was significantly high er than that in 30%～50%TBSA group(P < 0.05).The resistance of Pseudomon as aeruginosa to cephalosporins,quinolones,penicillins and carbapenems in 50%TBSA group was significantly higher than that in 30%～50%TBSA group.T he resistance of Acinetobacter baumannii to commonly used antimicrobial agen ts detected in patients with 50%TBSA was more than 90%,and the drug resista nce was significantly higher than that of strains detected in 30%～50%TBSA gr oup(P < 0.05)(5)The first three multidrug resistant strains were methicillin resistant Sta phylococcus aureus(Methicillin-Resistant Staphylococcus Aureus,MRSA),mult idrug resistant Acinetobacter baumannii(Multi-resistant Acinetobacter Baumann ii,MDR-AB)and multidrug resistant Pseudomonas aeruginosa(Multi-resistant P seudomonas Aeruginosa,MDR-PA).MRSA accounted for 35.3% of Staphyloco ccus aureus isolates(36max 102),and had no resistance to vancomycin and line zolid.MDR-AB showed pan-drug resistance,and the resistance rate to amikaci n and imipenem was more than 90%.The resistance to imipenem was 66.7%.o de,and the resistance rate to amikacin and imipenem was more than 90%.The r esistance of MDR-PA to imipenem was 66.7%.(6)The hospitalization time of patients with severe and extra severe burns ha d no significant difference among age and sex groups(P > 0.05),but there were significant differences in burn area,pathogen infection and mixed multi-drug r esistance infection group(P > 0.05).There was a significant positive linear rela tionship between hospital stay and burn area.Conclusions:(1)In this study,most of the adult patients with severe and extra severe bu rns were middle-aged males with flame burns.The older the age(≥ 50 years ol d),the larger the burn area,the more kinds of antimicrobials are taken,and the more likely to cause secondary infection after tracheotomy.(2)In this study,the main type of infection in adult patients with severe and extra severe burns was wound infection caused by Staphylococcus aureus.The larger the wound,the higher the detection rate of Pseudomonas aeruginosa.Mo st of the multi-drug resistant strains were MRSA,and no vancomycin resistant strains were found.The most serious drug resistance was MDR-AB.The mixed multi-drug resistant infection of pathogens would prolong the hospitalization ti me.(3)The drug resistance of pathogenic strains in 50%TBSA burn patients is strong,so anti-microbiogenic drugs should be reasonably selected according to the results of drug sensitivity,so as to avoid single long-term drug use and stric tly prevent the production of carbapenem-resistant negative bacteria(CR-GNB).