[A single center study on antimicrobial use and bacterial resistance in burn ward]

Objective: To investigate the effect of antibiotics on bacterial resistance through analyzing the use of common antibiotics and the bacterial prevalence in single-center burn ward. Methods: The epidemiological data of pathogenic bacteria and the use of common antibiotics in burn ward of Ruijin Hospital Affiliated to Shanghai Jiaotong University Medical College was investigated in the past 9 years. Bacteria samples were collected from the wounds, catheters, blood, feces, urine and sputum of inpatients in the unit from January 2010 to December 2018. The antibiotics use density was calculated by defined daily doses (DDDs)/(1 000 patient-days). Results: (1) In the proportion of bacteria detected, Staphylococcus aureus was the first and sensitive to glycopeptide antibiotics. Klebsiella pneumonia (19.8%), Pseudomonas aeruginosa (11.9%) and Acinetobacter baumannii (11.5%) were the top three Gram-negative bacteria in 2018; the proportion of Klebsiella pneumoniae was significantly increased (R(2)=0.861, P<0.001). (2) The Pseudomonas aeruginosa resistance rate to ceftazidime (R(2)=0.447, P=0.049) and ciprofloxacin (R(2)=0.663, P=0.008) increased significantly. The Klebsiella pneumoniae resistance rate to piperacillin (R(2)=0.999, P=0.018), meropenem (R(2)=0.999, P=0.023), ciprofloxacin (R(2)=1.000, P=0.010) increased significantly. There was no significant trend in the Acinetobacter baumannii resistance rate. (3) The use density of meropenem increased significantly (R(2)=0.492, P=0.035), and that of ciprofloxacin decreased significantly (R(2)=0.572, P=0.018). (4) Carbapenems use density was positively correlated with resistance rate of Klebsiella pneumoniae to cefoperazone sulbactam (r=0.733, P=0.025), piperacillin tazobactam (r=0.684, P=0.042), cefuroxime (r=0.821, P=0.023), ceftazidime (r=0.741, P=0.022), imipenem (r=0.718, P=0.029), meropenem (r=0.690, P=0.040), amikacin (r=0.750, P=0.020). (5) Ciprofloxacin use density was negatively correlated with the Pseudomonas aeruginosa resistance rate to ceftazidime (r=-0.751, P=0.020), Ciprofloxacin (r=-0.873, P=0.002) and with the Klebsiella pneumoniae resistance rate to cefuroxime (r=-0.767, P=0.044), ceftazidime (r=-0.712, P=0.031), imipenem (r=-0.780, P=0.013), meropenem (r=-0.793, P=0.011), ciprofloxacin (r=-0.871, P=0.002), Sulfamethoxazole/trimethoprim (r=-0.793, P=0.011). Conclusion: Carbapenems can induce Klebsiella pneumoniae to be multiple drug resistance; through the relationship between ciprofloxacin use intensity and drug resistance, the strategy of only restricting a certain antimicrobial agent may not restore the bacterial sensitivity.