心外科术后切口感染病原菌分布情况调查

目的调查心外科术后切口感染病原菌分布情况,指导临床抗感染防治。方法收集心外科术后患者临床资料。采集患者切口分泌物,经全自动微生物鉴定仪对病原菌类型进行鉴定;采用PCR法检测金黄色葡萄球菌毒力基因;对数据进行统计学分析。结果心外科手术患者496例,心外科术后切口感染患者35例,感染率7.06%;其中表浅切口感染患者22例,深部切口感染患者13例,分别占62.86%和37.14%,感染率分别为4.44%和2.62%;从心外科术后切口感染患者中共分离39株病原菌,其中革兰阳性菌21株、革兰阴性菌14株、真菌4株,构成比分别为53.85%、35.90%、10.26%;从表浅切口感染患者中分离革兰阳性菌13株,革兰阴性菌9株,真菌3株,构成比分别为52.00%、36.00%、12.00%;从深部切口感染患者中分离革兰阳性菌8株,革兰阴性菌5株,真菌1株,构成比分别为57.14%、35.71%、7.14%;分离自深部切口感染患者的金黄色葡萄球菌sasX、psm-mec、pvl毒力基因检出率分别为75.00%、25%、50%;分离自表浅切口感染患者的金黄色葡萄球菌sasX、psm-mec、pvl毒力基因检出率分别为62.50%、50.00%、37.50%。金黄色葡萄球菌毒力基因分布在表浅切口、深部切口感染中差异无统计学意义(P>0.05)。手术时间延长、术中失血、术中输血患者感染率分别为10.19%、11.17%和13.70%,感染率均高于其他患者,差异有统计学意义(P<0.05)。结论金黄色葡萄球菌是心外科术后切口感染的主要病原菌类型;金黄色葡萄球菌毒力基因与其临床致病性密切相关;手术时间延长、术中失血、术中输血是影响心外科患者术后切口感染发生的危险因素。

Examination of the distribution of pathogens causing a surgical site infection after cardiac surgery

Objective To examine the distribution of pathogens causing a surgical site infection after cardiac surgery in order to guide the clinical prevention and treatment of infections.Methods Clinical data on patients who underwent cardiac surgery were collected.Wound secretions were collected.The types of pathogens were identified by an automated microorganism identification system.PCR was used to detect Staphylococcus aureus virulence genes.Data were statistically analyzed.Results Four hundred and ninety-six patients underwent cardiac surgery and 35 patients developed a surgical site infection after cardiac surgery,for a rate of infection of 7.06%.There were 22 patients with a superficial surgical site infection(62.86%)and 13 patients with a deep surgical site infection(37.14%);the rate of infection was 4.44%in the former and 2.62%in the latter.A total of 39 strains of pathogens were isolated from patients with a surgical site infection after cardiac surgery.Twenty-one strains(53.85%)were Gram-positive bacteria,14 strains(35.90%)were Gram-negative bacteria,and 4 strains(10.26%)were fungi.Thirteen strains(52.00%)of Gram-positive bacteria,9 strains(36.00%)of Gram-negative bacteria,and 3 strains(12.00%)of fungi were isolated from patients with a superficial surgical site infection.Eight strains(57.14%)of Gram-positive bacteria,5 strains(35.71%)of Gram-negative bacteria,and 1 strain(7.14%)of fungi were isolated from patients with a deep surgical site infection.The virulence genes sasX,psm-mec,and pvl were respectively detected in S.aureus isolated from patients with a deep surgical site infection at a rate of 75.00%,25%,and 50%.The virulence genes sasX,psm-mec,and pvl were respectively detected in S.aureus isolated from patients with a superficial surgical site infection at a rate of 62.50%,50.00%,and 37.50%,respectively.The distribution of virulence genes in S.aureus did not differ significantly in superficial and deep surgical site infections(P>0.05).The rate of infection was 10.19%in patients with a prolonged operating time,11.17%in patients with substantial intraoperative blood loss,and 13.70%in patients receiving an intraoperative blood transfusion.The rate of infection was significantly higher than that in other patients(P<0.05).Conclusion S.aureus is the main pathogen causing a surgical site infection after cardiac surgery.The virulence genes of S.aureus are closely related to its clinical pathogenicity.A prolonged operating time,substantial intraoperative blood loss,and an intraoperative blood transfusion are risk factors for postoperative wound infection in patients undergoing cardiac surgery.