普外科切口感染病原菌分布及相关因素调查

目的研究普外科切口感染病原菌分布及相关因素,为临床感染预防提供参考。方法收集分析507例普外科围手术期患者档案资料。无菌采集手术切口分泌物,并进行培养和鉴定。采用Kirby-bauber纸片扩散法检测抗药性。分析不同年龄、性别、切口类型、手术时间、是否患有糖尿病和抗生素使用时机等患者切口感染情况。实时荧光PCR检测铜绿假单胞菌OprD2基因表达情况。结果507例患者中共有46例患者发生切口感染,感染率为9.07%。培养出46株病原菌,其中革兰阳性菌27株,革兰阴性菌19株。金黄色葡萄球菌、铜绿假单胞菌和表皮葡萄球菌是主要致病菌。革兰阳性菌对头孢呋辛酯、头孢曲松、头孢吡肟、诺氟沙星、环丙沙星、加替沙星、复方新诺明、红霉素、阿奇霉素、庆大霉素、阿米卡星和利福平耐药情况依次为:52.17%、47.83%、21.74%、48.15%、40.74%、3.70%、65.22%、81.48%、40.74%、43.48%、4.35%和11.11%。革兰阴性菌对头孢呋辛酯、头孢他啶、头孢吡肟、诺氟沙星、环丙沙星、加替沙星、复方新诺明、红霉素、阿奇霉素、庆大霉素、阿米卡星、美罗培南和亚胺培南耐药率依次为:84.21%、42.11%、31.58%、52.63%、47.37%、10.53%、84.21%、78.95%、21.05%、52.63%、10_53%、15.79%和5.26%。不同年龄、切口类型、手术时间、是否患有糖尿病和抗生素使用时机等患者切口感染率差异均有统计学意义(P<0.05)。11株铜绿假单胞菌中5株检出VIM、3株检出IMP,3株OprD2呈低表达或缺失,4株OprM高表达。讨论切口感染中铜绿假单胞菌分离数量较多,可能与它对临床使用抗生素天然耐药有关。OprD2呈低表达或缺失使得铜绿假单胞菌对碳青霉烯类抗生素耐受性上升。

Study on the distribution of pathogenic bacteria and factors related to surgical site infections in general surgery

Objective To study the distribution of pathogenic bacteria and factors related to surgical site infections in general surgery. Methods Data on 507 patients in general surgery were collected. Surgical site secretions were collected, and pathogenic bacteria were cultured and identified. The antibiotic resistance of the tested strains was determined using the Kirby-Bauer disk diffusion method. Whether development of a surgical site infection was significantly associated with age, gender, type of wound, operating time, diabetes mellitus, or the timing of antibiotic use was analyzed. Pseudomonas aeruginosa DNA was extracted and its resistance genes were detected, and expression of the Oprd2 gene was detected using real-time PCR. Results Of 507 patients, 46 had a surgical site infection for a rate of infection of 9.07%. Forty-six strains of pathogenic bacteria were isolated from 46 samples, including 27 strains of Gram-positive bacteria and 19 strains of Gram-negative bacteria. The pathogenic bacteria detected were mainly Staphylococcus aureus, P. aeruginosa, and Staphylococcus epidermidis. The resistance of Gram-positive bacteria to cefuroxime dipivoxil was 52.17%, their resistance to ceftriaxone was 47.83%, their resistance to cefepime was 21.74%, their resistance to norfloxacin was 48.15%, their resistance to ciprofloxacin was 40.74%, their resistance to gatifloxacin was 3.70%, their resistance to compound neoformans was 65.22%, their resistance to erythromycin was 81.48%, their resistance to azithromycin was 40.74%, their resistance to gentamicin was 43.48%, their resistance to amikacin was 4.35%, and their resistance to rifampin was 11.11%. The resistance of Gram-negative bacteria to cefuroxime dipivoxil was 84.21%, their resistance to ceftazidime was 42.11%, their resistance to cefepime was 31.58%, their resistance to norfloxacin was 52.63%, their resistance to ciprofloxacin was 47.37%, their resistance to gatifloxacin was 10.53%, their resistance to trimethoprim-sulfamethoxazole was 84.21%, their resistance to erythromycin was 78.95%, their resistance to azithromycin was 21.05%, their resistance to gentamicin was 52.63%, their resistance to amikacin was 10.53%, their resistance to meropenem was 15.79%, and their resistance to imipenem was 5.26%. Development of a surgical site infection differed significantly in terms of age, type of wound, operating time, diabetes mellitus, and the timing of antibiotic use(P<0.05). Of 11 strains of P. aeruginosa, 5 had the VIM gene, 3 had the IMP, 3 expressed a low level of or lacked the oprd2 gene, and 4 highly expressed the OprM gene. Discussion Numerous strains of P. aeruginosa were isolated from patients with a surgical site infection. This may be related to the bacterium’s natural resistance to antibiotics. The low expression or absence of OprD2 increased the resistance of P. aeruginosa to carbapenems.