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.

Clinical Efficacy and Safety Analysis of Tigecycline in the Treatment of Acute Exacerbation of Chronic Obstructive Pulmonary Disease Combined with Multidrug-Resistant Acinetobacter baumannii Infection

Objective:To study the clinical efficacy and safety of tigecycline in the treatment of acute exacerbation of chronic obstructive pulmonary disease(COPD)combined with multidrug-resistant Acinetobacter baumannii infection.Methods:113 patients with acute exacerbation of COPD combined with multidrug-resistant Acinetobacter baumannii infection were recruited between January 2021 and January 2023,and given tigecycline treatment.The total effective rate,lung function indexes,related biochemical index levels,and the incidence rate of adverse reactions were observed after the treatment.Results:After the treatment,100 patients were cured,1 case with apparent effect,2 cases were effective,10 cases were ineffective,and the total effective rate was 91.15%.The post-treatment CRP(21.22±3.35 mg/L),PCT(3.18±1.11 ng/L),CRE(76.36±9.24μmol/L),and ALT(37.76±6.99 U/L)were significantly improved as compared to the pre-treatment(P<0.05).After treatment,10 cases of vomiting(8.85%),13 cases of nausea(11.50%),4 cases of diarrhea(3.53%),1 case of abdominal pain(0.88%),and 2 cases of allergy(1.77%)were observed in 113 patients.Conclusion:Tigecycline therapy for patients with acute exacerbation of COPD combined with multidrug-resistant Acinetobacter baumannii infection not only has significant therapeutic efficacy but also has a high degree of safety.

Bloodstream Infection with Carbapenem-resistant Klebsiella Pneumoniae and Multidrug-resistant Acinetobacter Baumannii:a Case Report

IN the presence of septic shock, every hour in delaying the administration of effective antibiotics is associated with a measurable increase in mortality. This is especially true for neutropenic patients with septic shock. As there is a higher incidence of involving multi-drug resistant pathogens for neutropenic patients, the decision on antibiotics regime remains a challenge for physicians.2 Immunosuppression and previous antibacterial use are factors that promote the spread of multi-drug resistant pathogens, and the possibility of co-existing multi-drug resistant pathogens should be suspected when treating patients with these risk factors who developed refractory shock. Here we present a case with neutropenic fever and refractory shock whose blood culture yielded multi-drug resistant Acinetobacter baumannii and carbapenem- resistant Klebsiella pneumoniae.

Sequential intraventricular injection of tigecycline and polymyxin B in the treatment of intracranial Acinetobacter baumannii infection after trauma: a case report and review of the literature

Background:Intracranial infection after craniotomy is one of the most serious postoperative complications,especially multidrug-resistant(MDR)or extensively drug-resistant(XDR)bacterial meningitis,and strongly affects the prognosis of patients.Current treatment experience regarding these infections is scarce.Case presentation:We report a case of severe intracranial infection of XDR Acinetobacter baumannii(A.baumannii)that was treated by intravenous(IV)injection,sequential intraventricular(IVT)injection of tigecycline and polymyxin B,and other anti-infective drugs.Good results were obtained,and the patient was eventually discharged from the hospital.This case is characterized by intracranial infection.Conclusions:The polymyxin B IV+IVT pathway is an ideal treatment strategy for XDR A.baumannii.The tigecycline IVT pathway is also a safe treatment option.

Evaluation of the Protective Efficacy of a Fused OmpK/Omp22 Protein Vaccine Candidate against Acinetobacter baumannii Infection in Mice

Acinetobocter baumannfi （A. Baumannii） is an emerging opportunistic pathogen responsible for hospital-acquired infections, and which now constitutes a sufficiently serious threat to public health to necessitate the development of an effective vaccine. In this study, a recombinant fused protein named OmpK/Omp22 and two individual proteins OmpK and Omp22 were obtained using recombinant expression and Ni-affinity purification. Groups of BALB/c mice were immunized with these proteins and challenged with a clinically isolated strain of A. boumonnii. The bacterial load in the blood, pathological changes in the lung tissue and survival rates after challenge were evaluated. Mice immunized with OmpK/Omp22 fused protein provided significantly greater protection against A. boumonnfi challenge than those immunized with either of the two proteins individually. The results provide novel clues for future design of vaccines against A. boumonnii.

Risk Factors Associated with Acinetobacter baumannii Infections in Patients in an Intensive Care Unit of a Public Hospital in Paraná

To identify risk factors for A. baumannii infection in patients hospitalized in an Intensive Care Unit (ICU) of a tertiary public hospital in Paraná, Brazil, a retrospective paired case-control study (ratio 1:2) was conducted from January 2018 to December 2020. Patients in the case group were hospitalized in the ICU with A. baumanni (n = 68 cases) and were compared with patients in the control group, without infection by A. baumannii (n = 136). Both were matched by age (±10 years), sex, and ICU stay (±5 days). Conditional multiple logistic regression was used to determine statistically significant risk factors based on the results of bivariate analyses. Mortality was higher in infected (cases) than in non-infected patients (51.5% vs. 39.7%). The incidence and bacterial resistance increased annually. At bivariate analysis, cases had longer hospital stays (median 35 vs. 22 days, p A. baumannii and antimicrobial resistance. There is need for surveillance, and constant evaluation of control actions. Risk factors were colonization, previous hospitalization, and hospitalization time. This is essential for the decision-making of professionals and optimization of prevention, control, and therapeutic management actions.

Study on Distribution of Acinetobacter baumannii Complex in Dental Hospital Using Multiplex PCR

Purpose: In recent years, multidrug-resistant Acinetobacter baumannii has appeared and caused outbreaks of hospital infections all over the world. Close monitoring of this pathogen and other A. baumanii complex species is considered of critical importance to public health organizations. The reliable identification method able to distinguish A. baumannii from genetically close Acinetobacter species is needed, because these species are unable to be differentiated by phenotypic or biochemical methods. The purpose of the present study was to design species-specific primers in order to identify and detect A. baumanii complex species, and Acinetobacter lwoffii which is frequently detected from the human specimens, and to investigate the distribution of these organisms in dental hospital using a multiplex PCR. Methods: Polymerase chain reaction (PCR) primers were designed based on partial sequences of the 16S ribosomal RNA (16S rRNA) gene and DNA gyrase subunit B (gyrB) of each species of A. baumanii complex species. Swab samples were collected from ten dental spittoon units in dental hospital, and the distribution of A. baumanii complex species was investigated using a multiplex PCR. Results: These primers were able to distinguish each species of A. baumanii complex species clearly. A. baumanii and A. calcoaceticus were detected at 20.0% and 10.0% in ten swab samples, respectively. On the other hand, A. nosocomialis, A. lowffii, and A. pittii were detected from no sample. Conclusion: Our developed one-step multiplex PCR method is accurate, specific, cost-effective, time-saving, and worked without requiring DNA extraction.

Antimicrobial resistance in Acinetobacter baumannii : From bench to bedside

Acinetobacter baumannii(A. baumannii) is undoubtedly one of the most successful pathogens in the modern healthcare system. With invasive procedures, antibiotic use and immunocompromised hosts increasing in recent years, A. baumannii has become endemic in hospitals due to its versatile genetic machinery, which allows it to quickly evolve resistance factors, and to its remarkable ability to tolerate harsh environments. Infections and outbreaks caused by multidrugresistant A. baumannii(MDRAB) are prevalent and have been reported worldwide over the past twenty or more years. To address this problem effectively, knowledge of species identification, typing methods, clinical manifestations, risk factors, and virulence factors is essential. The global epidemiology of MDRAB is monitored by persistent surveillance programs. Because few effective antibiotics are available, clinicians often face serious challenges when treating patients with MDRAB. Therefore, a deep understanding of the resistance mechanisms used by MDRAB can shed light on two possible strategies to combat the dissemination of antimicrobial resistance: stringent infection control and antibiotic treatments, of which colistin-based combination therapy is the mainstream strategy. However, due to the current unsatisfying therapeutic outcomes, there is a great need to develop and evaluate the efficacy of new antibiotics and to understand the role of other potential alternatives, such as antimicrobial peptides, in the treatment of MDRAB infections.

Biofilm formation in clinical isolates of nosocomial Acinetobacter baumannii and its relationship with multidrug resistance

Objective: To check biofilm formation by Acinetobacter baumannii(A. baumannii)clinical isolates and show their susceptibility to different antibiotics and investigate a possible link between establishment of biofilm and multidrug resistance.Methods: This study was performed on clinical samples collected from patients with nosocomial infections in three hospitals of Tehran. Samples were initially screened by culture and biochemical tests for the presence of different species of Acinetobacter. Identifications were further confirmed by PCR assays. Their susceptibilities to 11 antibiotics of different classes were determined by disc diffusion method according to Clinical and Laboratory Standards Institute guidelines. The ability to produce biofilm was investigated using methods: culture on Congo red agar, microtiter plate, and test tube method.Results: From the overall clinical samples, 156 specimens were confirmed to contain A. baumannii. The bacteria were highly resistant to most antibiotics except polymyxin B.Of these isolates, 10.26% were able to produce biofilms as shown on Congo red agar.However, the percentage of bacteria with positive biofilm in test tube, standard microtiter plate, and modified microtiter plate assays were 48.72%, 66.66%, and 73.72%, respectively. At least 92% of the biofilm forming isolates were multidrug resistant.Conclusions: Since most of the multidrug resistant strains produce biofilm, it seems necessary to provide continuous monitoring and determination of antibiotic susceptibility of clinical A. baumannii. This would help to select the most appropriate antibiotic for treatment.

Acinetobacter baumannii:An emerging pathogenic threat to public health

Over the last three decades, Acinetobacter has gained importance as a leading nosocomial pathogen, partly due to its impressive genetic capabilities to acquire resistance and partly due to high selective pressure, especially in critical care units. This low-virulence organism has turned into a multidrug resistant pathogen and now alarming healthcare providers worldwide. Acinetobacter baumanni(A. baumannii) is a major species, contributing about 80% of all Acinetobacter hospital-acquired infections. It disseminates antibiotic resistance by virtue of its extraordinary ability to accept or donate resistance plasmids. The procedures for breaking the route of transmission are still proper hand washing and personal hygiene(both the patient and the healthcare professional), reducing patient's biofilm burden from skin, and judicious use of antimicrobial agents. The increasing incidence of extended-spectrum beta-lactamases and carbapenemases in A. baumannii leaves almost no cure for these "bad bugs".To control hospital outbreaks of multidrug resistantAcinetobacter infection, we need to contain their dissemination or require new drugs or a rational combination therapy. The optimal treatment for multidrug-resistant A. baumannii infection has not been clearly established, and empirical therapy continues to require knowledge of susceptibility patterns of isolates from one's own institution. This review mainly focused on general features and introduction to A. baumannii and its epidemiological status, potential sources of infection, risk factors, and strategies to control infection to minimize spread.

Antibacterial resistance patterns of Acinetobacter baumannii complex:The results of Isfahan Antimicrobial Resistance Surveillance-1 Program

Objective: To determine the antibiotic resistance patterns of the Acinetobacter(A.) baumannii complex isolates that cause the confirmed infection. Methods: The present descriptive study was performed from March 2016 to March 2018 in three referral hospitals in Isfahan, Iran. All A. baumannii complex strains isolated from different clinical samples were identified by conventional phenotypic methods and antibiotic susceptibility pattern was detected. After the clinical investigation, contaminated samples were excluded and the source(hospital/community) and site of the infection were determined. Data on antibiotic susceptibility testing were extracted from WHONET software and analysis was done with SPSS.Results: From 254 patients who had confirmed A. baumannii complex infection, 158(62.20%) cases were male, 27(10.63%) were less than 20 years old, 172(67.72%) had healthcare-associated infections and 96(37.79%) were admitted in intensive care units. The most frequent infection was bloodstream infections(111, 43.70%). Our results showed that most of the isolates were resistant to most of the antibiotics(more than 75.00%) and a lower rate of non-susceptibility was observed against minocycline(20, 44.44%) and colistin(0%). The rate of multidrug-resistant isolates was 88.97%. There was no significant difference between resistance of A. baumannii complex isolates according to age. However, the resistance to amikacin and minocycline and the rate of multidrug resistance(MDR) were significantly different between males and females. In patients with healthcare associated infection(HAI), MDR isolates were significantly different regarding admission in ICU ward. Resistance to levofloxacin and ciprofloxacin were lower in isolates from patients with bloodstream infections in comparison to other diagnoses.Conclusions: In our study, a high level of antibiotic resistance was detected in both community-acquired and healthcare-associated A. baumannii complex infections. Appropriate antibiotic prescription in a clinical setting is an essential need for the control and prevention of A. baumannii resistant infections.

Antibacterial activity and mechanism of X33 antimicrobial oligopeptide against Acinetobacter baumannii

Acinetobacter baumannii is a pathogenic bacterium widespread in human environments,especially in intensive care units,and is associated with high morbidity and infection rates.Multiple drug resistance in A.baumannii frequently leads to the death of patients,making the development of multi-effect antibacterial agents against this bacterium a research hotspot.We have previously found that the X33 antimicrobial oligopeptide can effectively inhibit the growth of Penicillium digitatum and Candida albicans.Herein,we evaluated the antibacterial activity of X33 antimicrobial oligopeptide against A.baumannii by determining the minimum inhibitory concentration,inhibition zone,and growth curve.The increase in extracellular alkaline phosphatase and the leakage of intracellular compounds confirmed the effect of X33 antimicrobial oligopeptide on the cell wall and membrane.Changes in reactive oxygen species,malondialdehyde,ATP,reducing sugar,soluble protein,and pyruvate content demonstrated that the incubation with X33 antimicrobial oligopeptide affected energy metabolism and oxidative stress.Consistent with the physiological characteristics,transcriptomics analysis indicated that incubation with X33 antimicrobial oligopeptide significantly induced changes in the expression of 2339 genes,including 1262 upregulated and 1077 downregulated genes,which participate in oxidative phosphorylation,ribosome,quorum sensing,fatty acid degradation,glycolysis/gluconeogenesis,and citrate cycle pathways.These results provide a fundamental basis for investigating the mechanism of X33 antimicrobial oligopeptide as a potential drug against A.baumannii.

碳青霉烯类耐药鲍曼不动杆菌感染的临床特征与耐药性分析

目的:探讨呼吸与危重症医学科碳青霉烯类耐药鲍曼不动杆菌(carbapenem resistant acinetobacter baumannii,CRAB)感染的临床特征以及对临床常用抗菌药物的耐药特性,以期为临床多重耐药细菌抗感染治疗提供理论依据。方法:回顾性收集2019年1月至2021年12月,在北京安贞医院呼吸与危重症医学科确诊为CRAB感染181例住院患者的病历资料,对其感染发生后的临床表现、合并症以及临床预后进行分析总结,根据临床标本分离的CRAB菌株体外药敏结果判断地区性耐药模式。结果:181例CRAB感染患者,总感染发生率为4.1%,65岁及以上老年人占比高达151例(83.4%)。慢性阻塞性肺疾病96例(53.0%)、支气管哮喘80例(44.2%)、支气管扩张症55例(30.4%)和肺部恶性肿瘤52例(28.7%)是需要患者住院治疗最常见的四类肺部基础疾病,同时大部分患者合并有高血压106例(58.6%)、糖尿病88例(48.6%)、心力衰竭50例(27.6%),既往或目前经历过心脏外科手术48例(26.5%)以及脑血管疾病43例(23.8%)和除肺部恶性肿瘤以外的其他实体器官肿瘤或血液系统肿瘤19例(10.5%)。临床标本最常来源于痰液128例(70.7%)和血液22例(12.2%)。体外药敏结果显示CRAB感染后对临床常用抗菌药物头孢吡肟(88.9%)和头孢他啶(85.1%)耐药率最高,其次是环丙沙星、头孢曲松、头孢唑林和左氧氟沙星,分别为65.7%、64.1%、62.4%、和56.4%,对替加环素和多黏菌素耐药率保持低度耐药,分别为6.1%和4.4%。研究期间,CRAB感染后住院患者全因死亡率为16.0%,与非碳青霉烯类耐药鲍曼不动杆菌感染住院患者全因死亡率(4.5%)等比较,差异有统计学意义(P=0.001);同时也发现,感染CRAB住院患者中位住院时间12d(7~18)d较非CRAB感染组患者7d(4~9)d明显延长,差异比较具有统计学意义(P=0.024)。结论:CRAB感染发生率高,并且对临床常用抗菌药物高度耐药,导致可供选择的抗菌药物治疗有限、住院期间病死率高,因此,早期识别耐药菌感染的高危人群,加强医院感染预防控制措施的实施,对降低耐药菌感染的发生率和病死率至关重要。

儿童耐碳青霉烯类鲍曼不动杆菌的感染分布和耐药情况及其危险因素分析

目的分析儿童耐碳青霉烯类鲍曼不动杆菌(CRAB)的感染分布和耐药情况,并探究其感染的危险因素。方法回顾性分析2015年1月至2021年12月郑州大学附属儿童医院收治的62例CRAB感染患儿的临床资料(病例组),另选取同期未感染CRAB的儿科患儿62例作为对照组,分析病例组患儿CRAB感染的分布情况和耐药情况,比较两组患儿的临床资料,并采用Logistics回归模型分析儿童感染CRAB的危险因素。结果62例患儿中以<1岁为主,占67.74%,以男童为主,占70.97%,以医院感染为主,占67.74%,标本主要来源分布于ICU,占66.13%。药敏试验结果显示,分离出的62株CRAB对氨曲南天然耐药,且耐药率最高,为100.00%,其次是哌拉西林、哌拉西林/他唑巴坦、头孢吡肟、亚胺培南、美罗培南,耐药率均为67.74%;对阿米卡星和复方新诺明较为敏感,耐药率分别为41.94%、46.77%。两组患儿的性别、住院时间、基础疾病、并发症、有创穿刺及引流、支气管镜、C反应蛋白(CRP)、降钙素原(PCT)比较差异均无统计学意义(P>0.05);病例组患儿的年龄明显低于对照组,碳青霉烯类抗生素暴露、中心静脉置管、机械通气、留置尿导管、WBC、NEU则明显高于对照组,差异均有统计学意义(P<0.05)。Logistic回归模型分析结果显示,碳青霉烯类抗生素暴露、中心静脉置管、机械通气、留置尿导管、白细胞计数(WBC)、中性粒细胞计数(NEU)均是儿童CRAB感染的独立危险因素(P<0.05)。结论本院CRAB感染患儿以医院感染为主,并且主要来自ICU,表现为多重耐药和泛耐药。碳青霉烯类抗生素暴露、中心静脉置管、机械通气、留置尿导管、WBC、NEU均是儿童CRAB感染的独立危险因素。

多重耐药鲍曼不动杆菌血流感染及感染后死亡危险因素分析

目的分析多重耐药鲍曼不动杆菌(MDR-Ab)血流感染及感染后死亡的危险因素。方法选择2021年1月—2023年1月本院收治的89例Ab血流感染患者作为研究对象,以菌株药敏试验结果为依据,将89例患者分为非多重耐药鲍曼不动杆菌(NMDR-Ab)感染组(15例)与MDR-Ab感染组(74例)。以病情转归为依据,将MDR-Ab感染组患者分为存活组(42例)与死亡组(32例)。收集、整理并分析入组者临床资料,对比NMDR-Ab感染组与MDR-Ab组患者临床资料,同时比较死亡组与存活组患者临床资料,以多因素Logistic回归模型分析MDR-Ab血流感染及感染后死亡的危险因素。结果MDR-Ab组在侵入性操作、入住ICU、机械通气、使用碳青霉烯类药物、使用抗真菌药物、抗真菌药物使用≥3 d、碳青霉烯类药物使用≥3 d、抗菌药物种类≥3种及死亡占比高于NMDR-Ab组(P<0.05);多因素Logistic回归分析显示,侵入性操作、使用碳青霉烯类药物及使用抗菌药物种类≥3种是MDR-Ab血流感染发生的独立危险因素(P<0.05);死亡组入住ICU、机械通气、感染前器官衰竭、合并免疫抑制状态、使用碳青霉烯类药物、使用喹诺酮类药物、使用抗真菌药物、使用碳青霉烯类药物≥3 d、使用抗真菌药物≥3 d及使用抗菌药物≥3种占比高于存活组(P<0.05);多因素Logistic回归分析显示,机械通气、感染前器官衰竭、合并免疫抑制状态及使用碳青霉烯类药物是MDR-Ab血流感染患者感染后死亡的独立危险因素(P<0.05)。结论使用碳青霉烯类药物、侵入性操作及抗菌药物使用≥3种是MDR-Ab血流感染发生的独立危险因素;机械通气、合并免疫抑制状态、感染前器官衰竭及使用碳青霉烯类药物是MDR-Ab血流感染患者感染后死亡的独立危险因素;临床应合理使用抗菌药物、控制机械通气、严格把控侵入性操作指征,依据以上危险因素制定干预措施,以此降低MDR-Ab血流感染率及死亡率。

老年患者耐碳青霉烯类鲍曼不动杆菌血流感染的危险因素和病死率:一项为期十年的回顾性研究

目的 评估老年患者发生耐碳青霉烯类鲍曼不动杆菌(CRAB)血流感染和28天短期死亡相关的危险因素,为预防和治疗CRAB血流感染提供依据。方法 回顾性分析玉林市某医院2013年1月—2022年12月确诊为鲍曼不动杆菌血流感染且年龄≥60岁的老年患者临床资料,包括患者人口统计学、微生物学相关特征及临床结局等数据。选取单变量分析有意义的变量进行二元logistic回归模型和Cox比例风险模型多变量分析,进一步确定感染的独立危险因素,采用Kaplan-Meier曲线进行生存分析。结果 共150例患者纳入研究,其中CRAB血流感染16例,占10.7%,碳青霉烯类敏感鲍曼不动杆菌(CSAB)血流感染134例。老年患者鲍曼不动杆菌血流感染28天短期病死率为15.3%(23/150,95%CI:9.6%~21.1%),其中CRAB血流感染短期病死率(56.3%,9/16)高于CSAB(10.4%,14/134)。深静脉置管(OR:15.598,95%CI:1.831~132.910)和合并其他部位感染(OR:15.449,95%CI:1.497~159.489)与老年患者发生CRAB血流感染相关。老年患者鲍曼不动杆菌血流感染28天死亡的独立危险因素为血液透析(OR:11.856,95%CI:2.924~48.076)、入住重症监护病房(OR:9.387,95%CI:1.941~45.385)和肺部感染为菌血症可疑来源(OR:7.019,95%CI:1.345~36.635)。结论 老年患者合并其他部位感染和深静脉置管与CRAB血流感染的发生相关。血液透析、入住重症监护病房和肺部感染为菌血症可疑来源是影响老年患者鲍曼不动杆菌血流感染预后的独立危险因素。

替加环素联合头孢哌酮/舒巴坦钠治疗多重/泛耐药鲍曼不动杆菌中枢神经系统感染有效性及安全性的Meta分析

目的 评价替加环素联合头孢哌酮/舒巴坦钠治疗多重/泛耐药鲍曼不动杆菌(MDRAB/XDRAB)中枢系统感染的效果和安全性,为MDRAB/XDRAB中枢神经系统感染的抗菌药物治疗提供循证学依据。方法 计算机系统检索万方数据库、中国生物医学文献数据库、维普中文科技期刊数据库、中国国家知识基础设施(CNKI)及Pubmed、Embase和Cochrane Library数据库,检索建库至2022年9月1日公开发表的有关替加环素及头孢哌酮/舒巴坦钠治疗MDRAB/XDRAB中枢神经系统感染的随机对照试验(RCT)文献。对纳入研究的文献使用Cochrane协作网偏倚风险评价工具进行质量评价,提取有效数据后采用RevMan5.4版软件进行Meta分析。结果 初筛文献184篇,最终纳入中文RCT研究4篇,样本量267例。Meta分析显示,联合疗法对MDRAB/XDRAB中枢神经系统感染的总疗效可能优于单药疗法[OR=4.30,95%CI=(1.93,9.58),P<0.01]。联合疗法对于细菌的清除有更好的效果[OR=4.20,95%CI=(2.08,8.48),P<0.01],且联合疗法产生的不良反应更少[OR=0.19,95%CI=(0.05,0.67),P<0.05]。联合疗法与单药疗法的治愈率差异无统计学意义(P>0.05)。结论 替加环素联合头孢哌酮/舒巴坦钠治疗MDRAB/XDRAB中枢神经系统感染较单药治疗可能有更好的临床疗效和安全性,受限于纳入研究的数量及质量,尚待更多更高质量的研究予以验证。

TLR2/TLR9激动剂对鲍曼不动杆菌肺部感染的保护作用

目的评价toll-like receptor(TLR)2/TLR9激动剂对肺部感染鲍曼不动杆菌(Acinetobacter baumannii,Ab)小鼠的保护作用。方法将6~8周龄雌性C57小鼠分为PBS组、Pam_(2)CSK_(4)(Pam)组、CpG ODN(CpG)组和Pam+CpG组,以不同剂量滴鼻免疫后24 h进行Ab肺部致死性感染,观察小鼠生存率。构建亚致死剂量Ab肺部感染模型,测定感染后小鼠血液、肺脏、肝脏、肾脏和脾脏的细菌定植量,并取小鼠肺脏和肾脏进行HE染色,分析病理损伤程度。探索免疫1、3、7 d后对小鼠Ab感染的保护作用,明确保护时间窗。Pam+CpG体外刺激A549上皮细胞和RAW264.7细胞,考察两种细胞对Ab的杀伤或吞噬作用。结果与PBS组比较,Pam+CpG组能显著提高Ab致死感染小鼠的生存率(P<0.05,P<0.01),降低亚致死感染后小鼠血液(P<0.01)、肺脏(P<0.01)、肝脏(P<0.05)、肾脏(P<0.01)和脾脏(P<0.01)的细菌定植量,减轻感染导致的病理损伤;在感染之前1 d或3 d免疫均可显著提高小鼠的生存率(P<0.05),其中免疫后3 d保护效果最好。与PBS、Pam、CpG组比较,Pam+CpG组可以显著促进A549上皮细胞和R AW264.7细胞对Ab的杀伤或吞噬作用(P<0.01)。结论TLR2/TLR9激动剂合用对Ab致死和亚致死感染均具有显著的保护作用,可能的机制是其促进了肺上皮细胞和巨噬细胞对Ab的杀伤或吞噬作用。

某三甲综合医院神经外科2019—2022年医院感染流行病学特征分析

目的调查分析济南市第四人民医院神经外科医院感染流行病学特征,为医院院感防控及抗菌药物合理使用提供参考依据。方法通过医院感染实时监控系统和医院信息系统回顾性收集2019年1月至2022年12月神经外科5200例住院患者感染相关信息,对其感染部位分布、院感发生率、病原菌分布及耐药情况等进行统计和描述性分析。结果2019—2022年,神经外科住院患者平均感染率为3.3%,呈逐年下降的趋势(趋势风险χ^(2)=39.000,P<0.001)。神经外科医院感染多为老年男性患者,感染发生部位以下呼吸道、泌尿系感染、菌血症、颅内感染为主。神经外科2019—2022年共检出病原菌296株,其中革兰氏阴性菌207株(69.9%);革兰氏阳性菌53株(17.9%);真菌36株(12.2%);前4位病原菌分别是肺炎克雷伯菌(21.6%)、铜绿假单胞菌(12.5%)、大肠埃希菌(9.8%)、鲍曼不动杆菌(8.8%)。药敏结果显示,鲍曼不动杆菌对碳青霉烯类抗菌药物耐药情况较为显著。结论该院神经外科这四年来医院感染发生情况逐年好转,检出病原菌以革兰氏阴性菌为主,耐药问题较为突出,应加强耐药管理。

宏基因组二代测序在耐碳青霉烯类鲍曼不动杆菌医院感染暴发中的应用

目的 探讨宏基因组二代测序(mNGS)技术在耐碳青霉烯类鲍曼不动杆菌(CRAB)医院感染暴发事件调查中的应用。方法 应用mNGS及传统病原学培养方法对某院重症监护病房(ICU)2023年6月8—22日5例检出CRAB患者进行病原学检测,对可能污染的环境进行微生物采样及细菌培养、鉴定和药物敏感试验,同时采取综合控制措施并评价其效果。结果 mNGS结果回报所需时间短于培养所需时间[(3.92±1.05)d VS (6.24±0.25)d,P<0.001]。5例患者的标本培养分离出CRAB,mNGS检测结果显示均检出OXA-23耐药基因,经专家综合判断4例患者为医院感染,1例患者为标本污染。依据《医院感染暴发控制指南》中的医院感染暴发定义,此事件考虑为医院感染暴发。环境卫生学监测结果显示,暴发时环境中CRAB检出率为51.30%(59/115),主要集中在医务人员手与呼吸机表面,实施多学科联合感染控制措施后,医生手卫生依从率及呼吸机消毒落实率分别由40.83%(49/120)、33.33%(16/48)提高至82.61%(95/115)、83.33%(30/36)。患者预后良好,后续监测未发现新病例,此医院感染暴发事件得到有效控制。结论 mNGS具有精准度高、耗时短、准确率高的特点,可以应用于医院感染暴发防控及耐药基因组研究,对多重耐药菌感染患者的抗感染治疗及医院感染防控措施的制定具有重要意义。持续提高消毒效果及手卫生依从率是防控CRAB感染的重要手段。