Phenotypic Detection of Enterobacterales Strains Susceptible of Producing OXA-48 Carbapenemase

Background: Nowadays, emergence of Carbapenemase-Producing Enterobacterales (CPE) throughout the world has become a public health problem, especially in countries with limited resources. In recent years, CPE of type OXA-48 (Ambler class D) have been identified in Dakar. The aim of this study was to evaluate the phenotypic detection of OXA-48 CPE using a temocillin disc (30 μg). Methodology: A retrospective study was carried out at Medical Biology Laboratory of Pasteur Institute in Dakar on Ertapenem-Resistant Enterobacterales (ERE) strains isolated from 2015 to 2017. These strains were then tested with a 30 μg temocillin disc. Any strain resistant to temocillin (inhibition diameter Results: Forty-one ERE isolated during the study period were tested, of which 34 (82.9%) were OXA-48 based on phenotypic detection using temocillin disc and confirmed by PCR (100%). OXA-48 CPE strains detected were composed of Klebsiella pneumoniae (n = 14;41.2%), Enterobacter cloacae (n = 8;23.5%), Escherichia coli (n = 7, 20.5%), Citrobacter freundii (n = 3;8.8%), Cronobacter sakazakii (n = 1;3%) and Morganella morganii (n = 1;3%). Conclusion: Temocillin resistance has a good positive predictive value for detecting OXA-48 CPE by phenotypic method, confirmed by PCR. Temocillin is therefore a good marker for detection of OXA-48 CPE except Hafnia alvei.

Epidemiology of carbapenem-resistant Acinetobacter baumannii colonization in neonatal intensive care units:A systematic review and meta-analysis

BACKGROUND The rising prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)in neonatal intensive care units(NICUs)represents an escalating challenge in healthcare settings,particularly in managing hospital-acquired infections(HAIs).Studies across various World Health Organization regions have documented a significant incidence of CRAB-related HAIs,with rates as high as 41.7 cases per 1000 patients in ICUs,accounting for 13.6%of all HAIs.These infections pose a doubled mortality risk compared to infections with carbapenem-susceptible Acinetobacter baumannii.A particularly concerning aspect of CRAB colonization is its asymptomatic nature,enabling its transmission through healthcare workers(HCWs)or the NICU environment to vulnerable neonates with developing immune systems.AIM To explore the prevalence of CRAB colonization in NICUs,focusing on neonates,healthcare workers,and the environmental samples,to enhance epidemiological understanding and inform targeted interventions.METHODS We conducted according to PRISMA 2020 checklist guidelines,a comprehensive literature search across multiple databases including MEDLINE(Ovid),EMBASE(Ovid),Global Health(Ovid),Web of Science,and Global Index Me-dicus.Studies were selected based on predetermined criteria,primarily involving neonates,HCWs,and environmental swabs,using culture or molecular methods to detect CRAB colonization.We excluded studies that did not specifically focus on NICUs,were duplicates,or lacked necessary data.The study selection and quality assessment were conducted independently by two reviewers.Data extraction involved collecting comprehensive details about each study.Our statistical analysis used a random-effects model to calculate the pooled prevalence and confidence intervals,stratifying results by regional location.We assessed study heterogeneity using Cochran's Q statistic and I²statistic,with regression tests employed to evaluate potential publication bias.RESULTS We analyzed 737 records from five databases,ultimately including 13 studies from ten countries.For neonates,the pooled prevalence was 4.8%(95%CI:1.1%to 10.5%)with the highest rates observed in South-East Asia(10.5%;95%CI:2.4%to 23.3%).Among HCWs,a single Indian study reported a 3.3%prevalence.Environmental samples showed a prevalence of 2.3%(95%CI:0%to 9.3%),with the highest rates in South-East Asia(10%;95%CI:4.2%to 17.7%).Significant heterogeneity was found across studies,and no publication bias was detected.CONCLUSION This systematic review highlights a significant prevalence of CRAB colonization in neonates across various regions,particularly in South-East Asia,contrasting with lower rates in high-income countries.The study reveals a gap in research on HCWs colonization,with only a single study from India reporting moderate prevalence.Environmental samples indicate moderate levels of CRAB contamination,again higher in South-East Asia.These findings underscore the need for more extensive and focused research on CRAB colonization in NICUs,including exploring the roles of HCWs and the environment in transmission,understanding antimicrobial resistance patterns,and developing effective prevention measures.

Association ofβ-lactam antimicrobial's exposure with carbapenem-resistant Pseudomonas aeruginosa infection:a cumulative meta-analysis

Background:Carbapenems are effective against severe Pseudomonas aeruginosa nosocomial infections.Therefore,carbapenem-resistant Pseudomonas aeruginosa is a serious public health threat.An understanding of the risk of inappropriate exposure to different antimicrobials in resistant Pseudomonas aeruginosa infection could help in elucidating the effective approach towards using antimicrobials in vulnerable patients with CRPA infection.Object:To investigate the association between exposure ofβ-lactam antimicrobials and CRPA infection relative to control patients.Methods:The MEDLINE/PubMed and OVID/Embase databases were used to search case-control and cohort studies in English language which reported antimicrobial exposure as risk factors for CRPA infection.The pooled odds ratios(OR)were calculated using a random-effect and fixed-effect model,and forest plots from a cumulative meta-analysis method were used to better show how pooled OR changed as updated evidence accumulated.Results:A total of 24 studies comprising 7039 participants were included for cumulative meta-analysis.A positive correlation was found between development of CRPA infection and exposure of beta-lactam antimicrobials:carbapenems(OR=7.60,95%CI:3.95 to 14.62,P<0.0001),imipenem(OR=9.81,95%CI:5.56 to 17.33),ampicillin(OR=1.86,95%CI:1.14 to 2.41),piperacillin(OR=2.82,95%CI:1.46 to 2.43),penicillins(OR=1.42,95%CI:0.90 to 2.24),cephalosporins(OR=1.88,95%CI:1.46 to 2.43)andβlactamase inhibitors(OR=1.96,95%CI:1.44 to 2.67).Further,exposure of other antimicrobial agents like quinolone(OR=2.35,95%CI:1.78 to 3.10),ciprofloxacin(OR=2.35,95%CI:1.66 to 3.95),aminoglycoside(OR=2.17,95%CI:1.60 to 2.95),amikacin(OR=3.11,95%CI:2.10 to 4.61),glycopeptides(OR=3.02,95%CI:1.92 to 4.75)and vancomycin(OR=3.26,95%CI:1.48 to 7.18),were also found to be positively associated with development of CRPA infection.Conclusions:Exposure of all kinds ofβ-lactams is significantly associated with development of carbapenemresistant Pseudomonas aeruginosa infection.These findings provide an impetus to take a more active approach while usingβ-lactam antimicrobials in patients with resistant Pseudomonas aeruginosa infections.

Burden of severe infections due to carbapenem-resistant pathogens in intensive care unit

Intensive care units(ICU)for various reasons,including the increasing age of admitted patients,comorbidities,and increasingly complex surgical procedures(e.g.,transplants),have become"the epicenter"of nosocomial infections,these are characterized by the presence of multidrug-resistant organisms(MDROs)as the cause of infection.Therefore,the perfect match of fragile patients and MDROs,as the cause of infection,makes ICU mortality very high.Furthermore,carbapenems were considered for years as last-resort antibiotics for the treatment of infections caused by MDROs;unfortunately,nowadays carbapenem resistance,mainly among Gram-negative pathogens,is a matter of the highest concern for worldwide public health.This comprehensive review aims to outline the problem from the intensivist's perspective,focusing on the new definition and epidemiology of the most common carbapenem-resistant MDROs(Acinetobacter baumannii,Pseudomonas aeruginosa and Enterobacterales)to emphasize the importance of the problem that must be permeating clinicians dealing with these diseases.

Anti-bacterial mechanism of baicalin-tobramycin combination on carbapenem-resistant Pseudomonas aeruginosa

BACKGROUND Pseudomonas aeruginosa(P.aeruginosa)is an important cause of nosocomial infections,and contributes to high morbidity and mortality,especially in intensive care units.P.aeruginosa is considered a'critical'category bacterial pathogen by the World Health Organization to encourage an urgent need for research and development of new antibiotics against its infections.AIM To investigate the effectiveness of baicalin combined with tobramycin therapy as a potential treatment method for carbapenem-resistant P.aeruginosa(CRPA)infections.METHODS Polymerase chain reaction(PCR)and RT-PCR were used to detect the expression levels of drug-resistant genes(including VIM,IMP and OprD2)and biofilmrelated genes(including algD,pslA and lasR)in CRPA that confer resistance to tobramycin,baicalin and tobramycin combined with baicalin(0,1/8,1/4,1/2 and 1MIC).RESULTS There was a correlation between biofilm formation and the expression of biofilmrelated genes.In addition,VIM,IMP,OprD2,algD,pslA and lasR that confer biofilm production under different concentrations in CRPA were significantly correlated.The synergistic effect of baicalin combined with tobramycin was a significant down-regulation of VIM,IMP,algD,pslA and lasR.CONCLUSION Baicalin combined with tobramycin therapy can be an effective treatment method for patients with CRPA infection.

Molecular Epidemiology and Risk Factors of Carbapenem-Resistant Klebsiella Pneumoniae Bloodstream Infections in Wuhan,China

Objective:The clinical characteristics and microbiological data of patients with K.pneumoniae bloodstream infections(BSI)from January 2018 to December 2020 were retrospectively analyzed to study the molecular epidemiology of Carbapenem-resistant Klebsiella pneumoniae(CRKP).We also aimed to identify the risk factors for the development of CRKP BSI.Methods:This retrospective study was conducted at Renmin Hospital of Wuhan University from January 2018 to December 2020.The date of non-duplicate K.pneumoniae isolates isolated from blood samples was identified using the microbiology laboratory database.The data from patients diagnosed with K.pneumoniae BSI were collected and analyzed.

Treatment of Donor-derived Carbapenem-resistant Klebsiella pneumoniae Infection after Renal Transplantation with Tigecycline and Extended-infusion Meropenem

Objective Donor-derived carbapenem-resistant Klebsiella pneumoniae(CRKP)infection has recently emerged as a critical early complication after renal transplantation.Although CRKP is usually sensitive to tigecycline,monotherapy with this drug is often less than effective.We investigated the efficacy of a combined regimen of tigecycline with high-dose,extended-infusion meropenem in the treatment of donor-derived CRKP infection after kidney transplantation.Methods From Jan.2016 to Dec.2017,a total of 12 CRKP isolates were detected from cultures of the organ preservation solution used for soaking the donor kidneys at our institute.Probable or possible donor-derived infection(DDI)was identified in 8 transplant recipients.Clinical data were retrospectively analyzed.Results Klebsiella pneumoniae carbapenemase-2(KPC-2)-producing CRKP was reported to be positive in organ preservation solution cultures at 3.5±0.9 days after transplantation,leading to surgical site(n=3),urinary tract(n=4),and/or bloodstream(n=2)infections in 8 recipients.The drug susceptibility tests showed that CRKP was sensitive to tigecycline,but resistant to meropenem.In 7 patients who received tigecycline combined with high-dose extended-infusion meropenem,DDIs were successfully cured.The length of hospital stay was 31(18–129)days,and the serum creatinine at discharge was 105.8±16.7µmol/L.The one remaining patient who received tigecycline combined with intravenous-drip meropenem died of septic shock.A median follow-up of 43 months(33–55)showed no recurrence of new CRKP infection in the 7 surviving recipients.Conclusion It was suggested that a prompt and appropriate combination therapy using tigecycline with high-dose extended-infusion meropenem is effective in treating donor-derived KPC-2-producing CRKP infection after renal transplantation.

成人肠道CRE定植病例医院感染发病率的Meta分析

目的系统评价成人肠道耐碳青霉烯类肠杆菌目细菌(CRE)定植病例医院感染发病率,为CRE医院感染的预防和控制提供参考依据。方法计算机检索Embase、Cochrane、PubMed、Web of Science、CNKI、万方、维普、中国生物医学文献数据库(CBM)8个数据库自建库至2023年6月CRE肠道定植病例医院感染发病率的相关文献,应用Stata 17.0软件进行Meta分析,采用敏感性分析评价研究结果的稳定性,采用Egger’s检验评价发表偏倚。结果共纳入16篇文献,其中英文11篇,中文5篇,总样本量2151例患者。Meta分析结果显示,成人肠道CRE定植病例医院感染发病率为23.1%(95%CI:14.8%~32.5%)。以不同研究设计类型、发表年份,以及研究调查的地域、科室和感染部位分组因素进行亚组分析,亚组间的合并效应量比较,差异均无统计学意义(均P>0.05)。在CRE定植发展为医院感染中,耐碳青霉烯类肺炎克雷伯菌(CRKP)占比96.0%(95%CI:86.8%~100%),定植病例中血流感染发病率为18.2%(95%CI:10.3%~27.6%)。CRE定植病例30天病死率为32.6%(95%CI:20.5%~45.9%),CRE感染病例30天病死率为36.9%(95%CI:16.0%~60.2%)。结论近年来CRE定植病例医院感染发病率较高,需对高危科室进行主动筛查和重点干预,以降低CRE定植病例医院感染发病率。

医院获得性耐碳青霉烯类肠杆菌目细菌血流感染危险因素

目的分析医院获得性耐碳青霉烯类肠杆菌目细菌(CRE)血流感染的特点及影响因素。方法采用回顾性巢式病例对照研究方法,选取2020年1月—2022年12月某三级综合医院发生医院获得性CRE血流感染的56例病例为CRE组,按1∶1选择同期56例碳青霉烯类敏感肠菌目细菌(CSE)血流感染患者为CSE组,分析感染菌株和科室分布,并通过单因素和多因素logistic回归分析CRE血流感染的相关因素。结果CRE血流感染科室分布以重症监护病房(ICU,23例,41.07%)和血液科(17例,30.36%)为主;感染菌株主要为肺炎克雷伯菌(32例,57.14%)和大肠埃希菌(16例,28.57%)。单因素分析结果显示,恶性肿瘤、60 d内住院史、感染前入住ICU>48 h、机械通气、留置中央静脉导管、使用二联及以上抗菌药物、抗菌药物使用时间≥10 d均与CRE血流感染有关(均P<0.05)。多因素logistic回归分析发现,感染前入住ICU>48 h、感染前抗菌药物使用时间≥10 d是医院获得性CRE血流感染的独立危险因素(P<0.05)。结论临床尤其是ICU应关注患者的流行病学史,尽早识别CRE血流感染高危因素的患者,同时合理使用抗菌药物,规范有创操作,以减少医院获得性CRE血流感染的发生。

2015-2021年CHINET儿童患者分离的肠杆菌目细菌耐药性变迁

目的了解2015-2021年CHINET儿童患者分离的肠杆菌目细菌的分布及耐药性变迁。方法采用纸片扩散法或商品化药敏试验自动测试仪器法按照CHINET技术方案进行药敏试验,并采用CLSI 2021年版标准判断结果。结果2015-2021年共收到儿童患者分离的肠杆菌目细菌81681株,占儿童革兰阴性杆菌的50.1%,其中大肠埃希菌、克雷伯菌属和肠杆菌属是最常见的细菌;菌株主要分离自尿液标本(29.3%)和呼吸道标本(27.7%)。儿童大肠埃希菌、肺炎克雷伯菌和奇异变形杆菌的ESBL检出率分别为48.8%~57.6%、49.3%~66.7%和23.1%~33.8%。儿童碳青霉烯类耐药肠杆菌目细菌的检出率为5.7%~9.5%,呈下降趋势,其中碳青霉烯类耐药克雷伯菌属、碳青霉烯类耐药肠杆菌属和碳青霉烯类耐药大肠埃希菌的检出率分别为14.1%~22.6%、7.1%~15.7%和2.0%~3.4%。肠杆菌目细菌对环丙沙星的耐药率高于左氧氟沙星;对阿米卡星、多黏菌素B和替加环素仍具有较好的敏感性。沙门菌属对氨苄西林耐药率>70%,而对头孢曲松耐药率<30%。结论儿童患者分离的肠杆菌目部分细菌(如大肠埃希菌、肺炎克雷伯菌)对常见抗菌药物耐药率呈下降趋势,但需加强细菌耐药性的持续监测,以预防和控制耐药菌的广泛播散。

2015~2019年重庆某三甲医院革兰阴性杆菌的分布特点和耐药性变迁

目的:对重庆某三甲医院2015~2019年期间临床分离的革兰阴性杆菌的分布和耐药性进行监测。方法:利用抗菌药物耐药性趋势监测(SMART)项目提交的重庆某医院革兰阴性杆菌标本,使用定制药敏板通过Trek系统进行抗菌药物敏感性测试。结果:共收集来自腹腔、呼吸道、尿路和血流感染患者的950株革兰阴性杆菌标本。其中大肠埃希菌、肺炎克雷伯菌、铜绿假单胞菌、鲍曼不动杆菌的检出率分别为43.37%、18.63%、14.11%、10.84%。鲍曼不动杆菌和铜绿假单胞菌对常规抗菌药物的耐药率较高但5年内变化较小。而肺炎克雷伯菌在2017年对第三代头孢菌素类和氟喹诺酮类药物的耐药率较2016年明显上升,对碳青霉烯类药物的耐药率在2019年降至20%以下。此外,不同感染部位的革兰阴性杆菌的耐药率也存在显著差异。其中,尿路感染来源的鲍曼不动杆菌对氟喹诺酮类抗菌药物左氧氟沙星和黏菌素均具有较高的敏感率;然而在腹腔和呼吸道感染中,其耐药率大多数超过50%。对于检出的耐碳青霉烯类鲍曼不动杆菌、对头孢噻肟或头孢曲松耐药的大肠埃希菌、耐氟喹诺酮类大肠埃希菌、多重耐药鲍曼不动杆菌和多重耐药铜绿假单胞菌,目前可选用的常规抗菌药物较少。结论:该院2015~2019年期间革兰阴性耐药菌的问题比较突出,尤其是三代头孢菌素耐药肠杆菌目细菌。而鲍曼不动杆菌无论是否为特殊耐药菌,对大部分抗菌药物的耐药率都很高,有待于持续监测并结合临床实际合理选择有效抗菌药物。

基于倾向性评分匹配的CRE感染经济负担增量研究

目的探讨重症监护病房(ICU)患者发生耐碳青霉烯类肠杆菌目(CRE)感染归因住院时间、住院费用和病死率。方法选取某三甲医院2017—2022年入住ICU的患者为研究对象,依据是否发生CRE感染分为感染组和非感染组。采用倾向性评分匹配法对感染组和非感染组患者进行1∶1匹配,统计分析匹配后患者的住院时间、住院费用和病死率。建立广义线性模型再次计算匹配后患者的住院时间、住院费用和病死率的比值比(OR值)。结果经过倾向性评分匹配,感染组较非感染组患者住院日数延长10.56 d(P<0.001),住院费用增加36021.02元(P<0.001),病死率增加6.70%(P=0.035)。广义线性模型结果显示,CRE感染患者相较于非感染患者,住院日数、住院费用和病死率OR值分别为1.187(95%CI:1.013~1.393)、1.134(95%CI:0.975~1.318)和1.130(95%CI:1.049~1.218),除住院费用外,两组住院日数和病死率比较,差异均存在统计学意义(均P<0.05)。结论ICU患者发生CRE感染会增加患者住院时间,加重患者经济负担,增加病死率,应采取措施进行防控。

临床分离碳青霉烯类耐药肠杆菌目细菌菌株的分子流行病学及碳青霉烯酶抑制剂增强试验的应用

目的:碳青霉烯类耐药肠杆菌目细菌(carbapenem-resistant Enterobacterales,CRE)的流行已成为临床抗感染治疗的巨大挑战。本研究探讨本地区CRE耐药情况及分子流行病学特征,并评估碳青霉烯酶抑制剂增强试验在临床实验室的应用价值,旨在为临床合理使用抗菌药物提供依据。方法:收集中南大学湘雅医院临床标本中分离的非重复性CRE,最低抑菌浓度(minimum inhibitory concentration,MIC)联合纸片扩散法(Kirby-Bauer,KB)检测菌株的药物敏感性,PCR方法检测13种碳青霉烯酶基因。使用碳青霉烯酶抑制剂增强试验对126株经PCR确定为产碳青霉烯酶的菌株进行表型检测,了解该方法与金标准PCR结果的符合程度。结果:704株CRE呈现出高度耐药的情况,经检测,501株为产碳青霉烯酶的肠杆菌目细菌(carbapenemase producing Enterobacterales,CPE);CPE菌株以肺炎克雷伯菌为主,其次为阴沟肠杆菌和大肠埃希菌;碳青霉烯酶有9种,包括肺炎克雷伯菌碳青霉烯酶(Klebsiella pneumoniae carbapenemase,KPC)、新德里金属β-内酰胺酶(New Delhi metallo-β-lactamase,NDM)、维罗纳整合子金属酶β-内酰胺酶(Verona integronencoded metallo-β-lactamases,VIM)、亚胺培南酶(imipenemase,IMP)、苯唑西林酶48型(oxacillinase-48,OXA-48)以及罕见的亚胺培南水解β-内酰胺酶(imipenem-hydrolyzingβ-lactamase,IMI)、阿德莱德亚胺培南酶(adelaide imipenemase,AIM)、圭亚那超广谱β-内酰胺酶(guiana extended-spectrumβ-lactamase,GES)和Bicêtre碳青霉烯酶(bicêtre carbapenemase,BIC),KPC型丝氨酸酶检出率最高,为61.7%(309/501);碳青霉烯酶抑制剂增强试验检测单产A类丝氨酸碳青霉烯酶、单产B类金属酶以及同时产A类和B类酶菌株的符合率均为100%。结论:湖南省长沙市CRE菌株分布非常广泛,产碳青霉烯酶(特别是KPC型丝氨酸酶)是这类细菌对碳青霉烯类药物耐药的主要机制。在湖南省长沙市首次检出了肠杆菌目细菌携带GES、IMI型基因。碳青霉烯酶抑制剂增强试验结果显示该方法能准确检测产A类丝氨酸酶和B类金属酶的CRE,且操作简单、结果容易判读,能满足临床微生物实验室丝氨酸碳青霉烯酶和/或金属酶检测的需求,为临床精准用药提供依据。

Antimicrobial approach of abdominal post-surgical infections

Abdominal surgical site infections(SSIs)are infections that occur after abdominal surgery.They can be superficial,involving the skin tissue only,or more profound,involving deeper skin tissues including organs and implanted materials.Currently,SSIs are large global health problem with an incidence that varies significantly depending on the United Nations’Human Development Index.The purpose of this review is to provide a practical update on the latest available literature on SSIs,focusing on causative pathogens and treatment with an overview of the ongoing studies of new therapeutic strategies.

耐碳青霉烯类肠杆菌目细菌耐消毒剂基因及四种消毒剂最低抑菌浓度检测

目的 了解临床分离耐碳青霉烯类肠杆菌目细菌(CRE)耐消毒剂基因qacE、qacE△1、qacE△1-SUL1携带情况,以及四种常用消毒剂最低抑菌浓度(MIC),为医院做好科学消毒提供参考依据。方法 收集某院2021年10月—2022年3月所有临床送检标本分离的CRE非重复菌93株,对菌株进行鉴定和药敏试验,采用聚合酶链反应(PCR)方法检测菌株耐消毒剂基因qacE、qacE△1和qacE△1-SUL1携带情况,采用琼脂稀释法检测戊二醛、碘伏、84消毒剂(含氯消毒剂)和乙醇对CRE的MIC值。结果 93株CRE以肺炎克雷伯菌(52株)和阴沟肠杆菌(25株)为主;CRE菌株耐药率较高,对大部分抗菌药物耐药率达100%;耐消毒剂基因qacE、qacE△1和qacE△1-SUL1携带率分别为72.0%(67株)、81.7%(76株)、89.2%(83株)。四种消毒剂对CRE的MIC值,戊二醛为500 mg/L,碘伏为625~2 500 mg/L,84消毒剂(有效氯浓度)为250~500 mg/L,乙醇为75%;碘伏中有4株CRE MIC值(2 500 mg/L)高于标准菌株,84消毒剂中有24株CRE MIC值(有效氯500 mg/L)高于标准菌株。结论 该院临床分离的CRE耐消毒剂基因携带率较高,部分CRE菌株对碘伏和84消毒剂有抗性,临床工作中需科学、规范地使用消毒剂,防止耐药菌医院内传播。

磷霉素联合多黏菌素B对碳青霉烯类耐药肠杆菌目细菌的体外抗菌活性分析

目的分析磷霉素联合多黏菌素B对碳青霉烯类耐药肠杆菌目细菌(carbapenem-resistant Enterobacterales,CRE)的体外抗菌活性。方法收集2020~2022年西安交通大学第二附属医院分离的CRE 78株,其中碳青霉烯类耐药大肠埃希菌(carbapenem-resistant Escherichia coli,CREC)32株、碳青霉烯类耐药肺炎克雷伯菌(carbapenem-resistant Klebsiella pneumonia,CRKP)46株;碳青霉烯类敏感肠杆菌目细菌(carbapenem-sensitive Enterobacterales,CSE)132株,其中碳青霉烯类敏感大肠埃希菌(carbapenem-sensitive Escherichia coli,CSEC)72株、碳青霉烯类敏感肺炎克雷伯菌(carbapenem-sensitive Klebsiella pneumonia,CSKP)60株。采用琼脂稀释法和肉汤微量稀释法(broth microdilution,BMD)分别测定磷霉素和多黏菌素B的最低抑菌浓度(minimum inhibitory concentration,MIC),采用肉汤微量稀释棋盘法测定CRE对磷霉素联合多黏菌素B的最低抑菌浓度,并计算部分抑菌浓度指数(fractional inhibitory concentration index,FIC),判定其联合效应。结果78株CRE中28株对磷霉素耐药,总耐药率为35.90%(28/78),其中6株同时还对多黏菌素B耐药,总耐药率为7.69%(6/78)。132株CSE中18株仅对磷霉素耐药,总耐药率为13.64%(18/132);未检测到对多黏菌素B耐药。多黏菌素B联合磷霉素对CREC为相加作用,对CRKP为协同作用。结论磷霉素和多黏菌素B单药耐药率均明显升高,二者联合用药可有效降低耐药率,提供一种新的治疗思路。

耐碳青霉烯类肠杆菌目细菌耐药性、临床感染特征及mcr基因分析

目的分析耐碳青霉烯类肠杆菌目细菌(CRE)临床感染特征及耐药机制,为临床防治CRE感染提供参考。方法收集2021年7月—2022年6月某三甲医院临床分离的CRE菌株及患者资料,采用聚合酶链反应(PCR)检测菌株耐药基因,诱导试验验证mcr-9阳性菌株的诱导耐药性。结果共纳入167株CRE,以肺炎克雷伯菌(38.9%)和阴沟肠杆菌(35.3%)为主,呈现多重耐药表型,3株(1.8%)对多粘菌素B耐药。CRE以携带bla NDM(52.1%,87株)为主,其次为bla KPC(34.7%,58株)。根据碳青霉烯酶将CRE感染患者分为NDM组和KPC组。单因素分析结果显示,在入住ICU日数≥7 d、行气管插管、感染前使用碳青霉烯类药物等影响因素方面,KPC组高于NDM组,治愈率低于NDM组(均P<0.05)。多因素logistic回归分析结果显示,置入胃管、肺部疾病及恶性肿瘤为影响携带不同碳青霉烯酶基因CRE感染患者预后的独立危险因素(P<0.05)。多粘菌素B耐药菌株均为mgr B点突变,7株(4.2%)CRE携带mcr-9,且多数同时携带bla NDM。经多粘菌素B诱导后,4株mcr-9阳性CRE的MIC值较诱导前升高。结论该地区CRE以携带bla NDM、bla KPC为主,少数同时携带mcr-9和bla NDM,呈现多重耐药。临床应加强防控,预防其临床传播。

2015—2020年某院CRE分布、耐药性及碳青霉烯酶基因检测结果分析

目的了解碳青霉烯耐药肠杆菌(CRE)的临床分布、耐药性及碳青霉烯酶基因型,为CRE感染的治疗及医院感染防控提供依据。方法收集2015年1月1日至2020年12月31日福建医科大学附属第二医院临床分离的CRE菌株,采用microflex LRF MALDI-TOF型质谱微生物鉴定仪进行菌种鉴定;采用微量肉汤稀释法或琼脂稀释法检测多黏菌素B、替加环素、头孢他啶/阿维巴坦和磷霉素等16种抗菌药物的最低抑菌浓度(MIC)。采用聚合酶链反应检测常见碳青霉烯酶基因(blaKPC、blaNDM、blaIMP、blaVIM、blaOXA-48)及黏菌素耐药基因mcr-1并测序确认;采用多位点序列分型(MLST)法确定肺炎克雷伯菌的序列分型(ST)。结果38株CRE中,肺炎克雷伯菌15株,大肠埃希菌13株,其他肠杆菌目细菌10株;主要分离自痰液、血液及尿液标本;来自普内科的分离率占比最高(23.69%);38株CRE对替加环素、多黏菌素B呈现较低耐药率(5.26%、13.16%),对阿米卡星、磷霉素、米诺环素和氨曲南的耐药率均<53%,对其他药物的耐药率均>71%。最常见的碳青霉烯酶基因型是blaNDM(65.71%),其次是blaKPC(22.86%)和blaIMP(8.57%),在15株肺炎克雷伯菌中鉴定出9种不同的ST,其中ST11型7株(46.67%)。结论该院CRE仅对替加环素、多黏菌素B等少数抗菌药物呈现较好敏感性,产blaNDM型碳青霉烯酶是肠杆菌目细菌对碳青霉烯类抗菌药物耐药的主要原因;ST11型肺炎克雷伯菌是碳青霉烯耐药肺炎克雷伯菌的主要流行克隆菌株,未发现该地区的克隆菌株暴发流行。

2021年南昌大学第一附属医院细菌耐药性监测

目的了解2021年南昌大学第一附属医院临床分离菌的分布及对常用抗菌药物的敏感性。方法收集该院2021年1月1日—12月31日非重复临床分离株,采用自动化仪器或纸片扩散法按照CHINET统一监测方案进行抗菌药物敏感性试验。按2021年CLSI文件标准判断结果,WHONET 5.6软件进行耐药性分析。结果共收集非重复临床分离菌9024株,其中革兰阳性菌2149株,占23.8%,革兰阴性菌6875株,占76.2%。甲氧西林耐药金黄色葡萄球菌(MRSA)和甲氧西林耐药凝固酶阴性葡萄球菌(MRCNS)检出率分别为30.8%和68.2%,未发现万古霉素和替加环素耐药株。92.3%MRSA对甲氧苄啶-磺胺甲唑敏感,89.4%MRCNS对利福平敏感。肠球菌属中粪肠球菌对多数抗菌药物的耐药率显著低于屎肠球菌,但对利奈唑胺的耐药率(2.4%)高于屎肠球菌(0.3%),两者中均有少量万古霉素耐药株。肺炎链球菌青霉素耐药株检出率为14.3%。肠杆菌目细菌中,除克雷伯菌属对碳青霉烯类抗生素耐药率高于40%外,其余菌属对碳青霉烯类药物仍较敏感。碳青霉烯类耐药肠杆菌目细菌(CRE)的检出率为28.3%,其中肺炎克雷伯菌在CRE菌株中占76.4%。不动杆菌属对亚胺培南和美罗培南的耐药率分别为75.5%和81.1%,铜绿假单胞菌对两药的耐药率分别为33.6%和30.5%。结论临床分离株对常用抗菌药物耐药率呈增长趋势,尤其是碳青霉烯类耐药革兰阴性杆菌,对临床抗感染治疗带来巨大挑战,医院各相关部门应加强协作以遏制耐药细菌的传播。

胶体金免疫层析法在碳青霉烯酶检测中的价值及应用

目的系统性评价胶体金免疫层析法在耐碳青霉烯类肠杆菌目细菌(CRE)碳青霉烯酶型检测中的价值及性能情况,为实验室进行CRE碳青霉烯酶快速检测提供可靠依据。方法对收集的70株无菌部位分离的CRE菌株同时使用PCR扩增、基因测序和胶体金免疫层析法进行碳青霉烯酶型检测,以测序结果为参考标准,评价胶体金免疫层析法的实验室检测性能。结果检出碳青霉烯酶基因69株,其中KPC型49株,OXA-48型12株,IMP型1株,NDM型3株,同时检出KPC和OXA-48型2株,同时检出OXA-48和NDM型1株,同时检出KPC和NDM型1株,未检出以上5种基因型1株。胶体金免疫层析法结果与测序结果相比灵敏度100%,特异度97.1%。不符合2株,其中1株为测序结果同时存在KPC和OXA-48两种型,胶体金检测结果为KPC型;1株为测序结果同时存在KPC和NDM两种型,胶体金检测结果为KPC型。结论胶体金免疫层析法作为一种新的CRE碳青霉烯酶型检测方法,操作简单,结果容易判读,能够短时间内检测出CRE中的产KPC、OXA-48、VIM、IMP和NDM型碳青霉烯酶的情况,灵敏度和特异度能够满足临床需求,可作为实验室进行碳青霉烯酶型快速检测的方法,指导临床诊治CRE。