摘要
目的分析血液培养中凝固酶阴性葡萄球菌污染发生率、菌种分布及耐药特征,明确污染相关危险因素。方法回顾性研究2022-2024年1864份血培养标本,确诊CoNS污染102例(污染组),随机抽取真性菌血症108例(真感组)。记录两组基础疾病、采血参数。病原体鉴定采用MALDI-TOF MS,药敏试验遵循CLSI 2023标准。污染判定依据单套阳性、重复培养阴性、炎症标志物阈值及临床无凝固酶阴性葡萄球菌靶向抗菌治疗用药记录。结果CoNS总污染率5.5%(102/1864)。污染组表皮葡萄球菌占62.7%(64/102),显著高于溶血葡萄球菌21.6%(22/102)及人葡萄球菌9.8%(10/102)。药敏显示污染株对苯唑西林耐药率85.3%(87/102),红霉素76.5%(78/102),左氧氟沙星47.1%(48/102);对万古霉素、替考拉宁、利奈唑胺均敏感。急诊科采血污染率11.7%(34/290)显著高于病房4.2%(68/1574)(P=0.003);采血量<8ml/瓶者污染率13.9%(25/180)高于标准采血量组4.6%(77/1684)(P<0.001)。Logistic回归证实急诊采血(OR=3.12,95%CI 1.89-5.15)及采血不足(OR=2.97,95%CI 1.75-5.04)为独立危险因素。结论血培养CoNS污染以表皮葡萄球菌为主,呈现多重耐药特性但保留糖肽类药物敏感性。急诊采血及采血量不足显著增加污染风险,需强化操作规范以降低假阳性率。
Objective To analyse the incidence,species distribution,and antimicrobial resistance characteristics of coagulase-negative staphylococci(CoNS)contamination in blood cultures,and to identify risk factors associated with contamination.Method A retrospective study of 1,864 blood culture specimens collected between 2022 and 2024 identified 102 cases of confirmed CoNS contamination(contamination group).A random sample of 108 cases of true bacteraemia(true infection group)was selected.Baseline conditions and blood collection parameters were recorded for both groups.Pathogen identification employed MALDI-TOF MS,with antimicrobial susceptibility testing adhering to CLSI 2023 standards.Contamination was defined by:single-set positivity,negative repeat cultures,inflammatory marker thresholds,and absence of targeted antimicrobial therapy for CoNS.Result Overall CoNS contamination rate was 5.5%(102/1864).Staphylococcus epidermidis constituted 62.7%(64/102)of the contamination group,significantly higher than Staphylococcus pyogenes(21.6%,22/102)and Staphylococcus hominis(9.8%,10/102).Antibiotic susceptibility testing revealed 85.3%(87/102)resistance to cefazolin,76.5%(78/102)to erythromycin,and 47.1%(48/102)to levofloxacin;all strains remained susceptible to vancomycin,teicoplanin,and linezolid.The contamination rate in the emergency department(11.7%,34/290)was significantly higher than that in inpatient wards(4.2%,68/1574)(P=0.003).The contamination rate in samples with<8 ml/bottle was 13.9%(25/180),higher than that in the standard volume group(4.6%,77/1684)(P<0.001).Logistic regression confirmed that emergency blood collection(OR=3.12,95%CI 1.89-5.15)and insufficient blood volume(OR=2.97,95%CI 1.75-5.04)were independent risk factors.Conclusion Contamination of blood cultures by coagulase-negative staphylococci predominantly involved Staphylococcus epidermidis,exhibiting multidrug resistance while retaining susceptibility to glycopeptide antibiotics.Emergency blood sampling and insufficient blood volume significantly increased contamination risk,necessitating enhanced procedural standards to reduce false-positive rates.
作者
张翰庭
王晶
Hanting Zhang;Jing Wang(Gansu Medical College,Lanzhou,Gansu 734001;The First People's Hospital of Longnan City,Longnan,Gansu 746000)
出处
《医学研究前沿》
2025年第8期92-95,共4页
Frontiers of Medical Research
关键词
血液培养
凝固酶阴性葡萄球菌
污染率
抗菌药物敏感性
blood culture
coagulase-negative staphylococci
contamination rate
antimicrobial susceptibility
