基金项目：国家自然科学基金（81860338）
Analysis of pathogens distribution and risk factors of burn infections in burn patients
YangJun-ying1, Liu-min2, Liang-kai1, PanWen-dong3, Zhao-yao3, YaoZhi-hui3
1Laboratory Department, the 926 Hospital of PLA, Kaiyuan661600, China; 2Department of disease control and Prevention, the 926 Hospital of PLA, Kaiyuan 661600, China; 3Department of burns, the 926 Hospital of PLA, Kaiyuan661600, China
Corresponding auther: YaoZhi-hui, Email: yaozh198794@163.com
[Abstract]  Objective To investigate and analyze the distribution of pathogens in the  burn patients with infection, and to analyze the related risk factors to infection, so as to provide theoretical basis for clinical effective control and prevention of wound infection in burn patients. Methods All the burn patients who were detected the pathogens in our hospital from January 2016 to December 2020 were selected, and collecting the clinical data for retrospective analysis. Results A total of 245 burn patients were examined for wound secretions, including 184 patients with bacterial infection, the incidence rate of 75.10 %, 79 patients were multi-drug resistant, accounting for 42.93 %. Totally 367 strains of pathogens have been isolated from wound secretions obtained from 184 patients, including 72 (19.62 %) strains were Gram-positive bacteria, mainly Staphylococcus aureus (11.44 %), 283 (77.11 %) strains were gram-negative bacteria, mainly Pseudomonas aeruginosa (20.16 %) and Acinetobacter baumannii (19.89 %), 12 (3.27 %) strains were fungi, mainly Aspergillus (1.91 %). The results of drug sensitivity tests showed that the pathogens of burn patients were highly resistant to common antibiotics. Monofactor analysis showed that age, burn area, wound depth, hypovolemic shock and length of hospital stay may be risk factors for wound infection. Multivariate logistic regression analysis showed that age below the 4 years old or over 69 years old, burn area > 30 %, wound depth is III degree, length of hospital stay ≥ 15 days were the high risk factors of wound infection in burn patients (P < 0.05). Conclusions In the treatment of burn patients, it is necessary to deal with the wound in time and monitor the pathogen status, according the drug sensitivity results to select appropriate antibiotics, at the same time implement contact isolation for multi-drug resistant patients, paying attention to the patients with high risk factors, so as to reduce the occurrence of wound infection and hospital infection.
[Key Words]  burn patients; infection; drug resistance rate; risk factors
Fund Program: National Natural Science Foundation of China (81860338) 

烧伤患者由于天然皮肤屏障的完整性被破坏，毛细血管通透性增加，使得病原微生物极易穿过破损皮肤或受损的肠粘膜侵入机体，同时烧伤创面多伴有大量坏死组织和炎性渗出，促炎和抗炎信号通路的激活，使得先天和适应性免疫反应失调，最终导致烧伤患者感染发生率居高不下[1][2][3]。烧伤创面感染不仅会导致创面延迟愈合、瘢痕组织增生[4]，而且一旦病原体侵入真皮下的组织层还可能会导致菌血症、败血症和多器官功能障碍综合征等，危及患者生命[5]。迄今为止，感染仍是烧伤患者最常见的并发症，也是造成严重烧伤患者死亡最主要的原因之一，约占烧伤死亡患者中42 %-65 %[6][7][8]。导致烧伤患者创面感染的危险因素有多种，同时感染也为患者的恢复和相关预后带来诸多的不良影响，因此本研究收集了某部队医院2016-2020年245例烧伤患者送检的创面分泌物病原菌培养及药敏结果，并对其病例进行回顾性分析，以期为临床有效预防和控制烧伤患者创面感染提供理论依据。
1 资料与方法
1.1 一般资料 选取2016年1月-2020年12月烧伤科进行创面分泌物送检的烧伤患者共245例作为研究对象，其中男性183例，女性62例，患者年龄最大89岁，最小10个月，平均年龄（24.62±11.60）岁。患者烧伤面积最大为98%，最小为1%，平均（23.43±22.72）%；住院时间最长为273天，最短为5天，平均（33.85±31.76）天。
1.2 方法 
1.2.1 分泌物样本采集：烧伤创面首先用无菌生理盐水清洗，然后用无菌棉拭子采集患者创面深部分泌物，立即送检进行细菌学培养。
1.2.2 病原菌及药敏鉴定：根据《全国临床检验操作规程》[9]对病原菌进行分离鉴定，使用VITEK2 compact system（法国梅里埃生物公司）全自动微生物鉴定及药敏分析系统对创面病原菌分布及其对抗菌药物的敏感性进行分析。在监测过程中若涉及同一病人多部位取材培养结果为同一种病原菌或一周内重复送检样本培养结果与上次结果一致，则仅保留一次检测结果。多重耐药诊断标准以2011年卫生部颁布的《多重耐药菌医院感染预防与控制技术指南（试行）》为依据，是指对临床使用的3类或3类以上抗菌药物同时呈现耐药的细菌。
1.2.3收集患者一般资料、致伤因素、烧伤面积及深度、有无基础疾病、是否伴有休克等临床资料。依据是否发生创面感染将患者分为感染组和未感染组，诊断标准如下: ①创面存在脓性分泌物; ②创面分泌物细菌培养分离出病原菌; ③存在明显局部症状，如创面出现压痛、肿胀伴有发热症状等。符合条件者将其纳入感染组，否则纳入未感染组。
1.2.4 统计分析 采用SPSS22.0软件对所有数据进行统计学分析。计量资料均以均值±标准差表示，两组间比较采用独立样本t检验；计数资料以例数（百分比表示），组间比较采用χ2检验。组间比较有统计学差异的因素重新进行变量赋值纳入多因素Logistics回归分析。当P<0.05时，认为差异具有统计学意义。
2 结果
2.1 创面感染阳性率 本研究中共收集245例烧伤患者病例，共送检创面分泌物样本531份。经创面细菌培养后，阳性184例，患者创面感染率为75.10 %，其中分离出多重耐药菌的患者多达79例，占培养结果阳性患者的42.93 %。