自上世纪90 年代以来, 多耐药非发酵革兰阴性杆菌开始成为医院感染的重要病原菌, 并迅速增加, 其中不动杆菌( Acinetobacter) 尤其令人关注。鲍曼不动杆菌( Acinetobacter baumannii) 或称鲍曼-醋酸钙不动杆菌复合群, 占不动杆菌的80% ～90% , 是不动杆菌中引起人类感染的主要菌群, 具有极强的环境适应能力、获得外源性耐药基因的能力及播散性, 因而被称为21 世纪革兰阴性菌中的“耐甲氧西林金黄色葡萄球菌( MRSA) ”, 值得引起临床医生的重视。
Objective To investigate the drug resistance and homogeneous analysis of Acinetobacter baumanii in emergency intensive care unit ( EICU) . Methods Four multidrug-resistant Acinetobacter baumannii ( MDR-Ab) strains isolated fromnosocomial inpatients fromJuly 25 to September 7 in 2009 were collected and tested for drug sensitivity and MIC determination as well. The A. baumannii isolates were typed with pulsed-field gel electrophoresis ( PFGE) to determine whether they derived fromthe same clone.Results Four isolates from nosocomial inpatients were resistant to multiple antibiotics including carbapenem. The PFGE types identified from four isolates were A and B. The A. baumannii isolates did not derived from the same clone. Conclusion The prevalence of nosocomial infection is not due to transmission of the same strains among different individuals in EICU.
ObjectiveTo explore the infection condition of Acinetobacter baumannii at the Neurosurgery Intensive Care Unit (NICU), and analyze the possible risk factors. MethodsWe retrospectively analyzed the clinical data of Acinetobacter baumannii infection patients with craniocerebral injury treated at the NICU between January 2011 and June 2013. We collected such information as infection patients' population distribution, infection site, invasive operations and patients' nurse-in-charge level and so on, and analyzed the possible risk factors for the infection. ResultsThirty-one patients were infected with Acinetobacter baumannii, and they were mainly distributed between 60 and 80 years old. The main infection site was lower respiratory tract, followed in order by urinary tract, gastrointestinal tract, skin and soft tissue. The risk factors might be related to age, invasive operation, nurse working ability, etc. ConclusionThe patients at the NICU are vulnerable to infection of Acinetobacter baumannii. Reducing invasive diagnosis and nursing procedures, providing optimal care, and carrying out specialized nurse standardization training may be the important means to effectively reduce the infection.
Objective To investigate the predictors for carbapenem-resistant Acinetobacter baumannii, Enterobacteriaceae and Pseudomonas aeruginosa (CR-AEP) as the pathogens of bloodstream infection (BSI) for intensive care unit (ICU) patients. Methods A retrospective case-control study based on ICU- healthcare-associated infection (HAI) research database was carried out. The patients who have been admitted to the central ICU between 2015 and 2019 in the ICU-HAI research database of West China Hospital of Sichuan University were selected. The included patients were divided into two groups, of which the patients with ICU-acquired BSI due to CR-AEP were the case group and the patients with BSI due to the pathogens other than CR-AEP were the control group. The clinical features of the two groups of patients were compared. Logistic regression model was used to identify the predictors of BSI due to CR-AEP.ResultsA total of 197 patients with BSI were included, including 83 cases in the case group and 114 cases in the control group. A total of 214 strains of pathogenic bacteria were isolated from the 197 BSI cases, including 86 CR-AEP strains. The results of multivariate logistic regression analysis showed that previous use of tigecycline [odds ratio (OR)=2.490, 95% confidence interval (CI) (1.141, 5.436), P=0.022] was associated with higher possibility for CR-AEP as the pathogens of BSI in ICU patients with BSI, while previous use of antipseudomonal penicillin [OR=0.497, 95%CI (0.256, 0.964), P=0.039] was associated with lower possibility for that. Conclusion Previous use of tigecycline or antipseudomonal penicillin is the predictor for CR-AEP as the pathogens of BSI in ICU patients with BSI.
ObjectiveTo investigate clinical characteristics and influencing factors of lower respiratory tract infection of Acinetobacter baumannii (AB-LRTI) in respiratory intensive care unit (RICU).MethodsClinical data were collected from 204 RICU patients who were isolated Acinetobacter baumannii (AB). The bacteriological specimens were derived from sputum, bronchoscopic endotracheal aspiration, bronchoalveolar lavage fluid, pleural effusion and blood. The definition of bacterial colonization was based on the responsible criteria from Centers for Disease Control and Prevention/National Medical Safety Network (CDC/NHSN). The patients were divided into three groups as follows, AB colonization group (only AB was isolated, n=40); simple AB-LRTI group (only AB was isolated and defined as infection, n=63), AB with another bacteria LRTI group (AB and another pathogen were isolated simultaneously, n=101). The epidemiology, clinical characteristics and influencing factors of each group were analyzed and compared. ResultsCompared with the AB colonization group, the AB with another bacteria LRTI group had higher proportion of patients with immunosuppression, specimens from sputum and bronchoalveolar lavage fluid, more than 4 invasive procedures, 90-day mortality, white blood cell count >10×109/L (or <4×109/L), neutrophil percent >75% (or <40%), lymphocyte count <1.1×109/L, platelet count <100×109/L, albumin <30 g/L, high sensitivity C-reactive protein >10 mg/L, and neutrophil-to-lymphocyte ratio (NLR). The frequency of bronchoscopy and days of infusing carbapenem within 90 days before isolating AB, the Acute Physiology and Chronic Health Evaluation Ⅱ score, the proportion of patients with invasive mechanical ventilation and the duration of invasive mechanical ventilation in the AB with another pathogen LRTI group were higher than those in the AB colonization group (all P<0.05). Days of infusing carbapenem and β-lactams/β-lactamase inhibitors within 90 days before isolating AB, proportion of septic shock, NLR and 90-day mortality of the patients from the AB with another pathogen LRTI group were more than those in the simple AB-LRTI group (all P<0.05). After regression analysis, more than 4 invasive procedures, or immunosuppression, or with more days of infusing carbapenem within 90 days before isolating AB were all the independent risk factors for AB-LRTI.ConclusionsThere are significant differences in epidemiology, clinical symptoms and laboratory indicators between simple AB-LRTI, AB with another pathogen LRTI and AB colonization in RICU patients. For RICU patients, who suffered more than 4 invasive procedures, immunosuppression, or with more days of infusing carbapenem within 90 days before isolating AB, are more susceptible to AB-LRTI.
Objective To analyze the clinical characteristics, mortality risk and risk factors of patients with carbapenem resistant Acinetobacter baumannii (CRAB), so as to provide references for the prevention and control of CRAB. Methods Inpatients with Acinetobacter baumannii were selected from the clinical samples in the intensive care unit of Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital between January 2018 and December 2021. The patients were divided into CRAB infection group, carbapenem-sensitive Acinetobacter baumannii (CSAB) infection group and CRAB colonization group. Survival analysis was used to analyze the mortality risk and its influencing factors in patients with CRAB infection. Results A total of 696 patients were included. Among them, there were 392 cases of CRAB infection, 267 cases of CRAB colonization, and 37 cases of CSAB infection. The factors that increased the 30-day mortality risk of CRAB mainly included blood transfusion or use of blood products, mechanical ventilation, respiratory failure, maximum procalcitonin and age. Kaplan-Meier analysis showed that the 30-day mortality risk of CRAB infection group was higher than that of CSAB infection group（χ2=4.837, P=0.028), there was no significant difference between CRAB infection group and CRAB colonization group in 30-day mortality risk（χ2=0.219, P=0.640). Conclusions The mortality risk of CRAB infected patients is higher. Compared with the infection status, the 30-day mortality risk of patients is more attributed to drug resistance status. The effective method to control the mortality rate of CRAB should focus on reducing the hospital acquisition rate of CRAB.
ObjectiveTo study the clinical distribution and the change of drug resistance of Acinetobacter baumannii from different inpatient specimens sources during 2008 to 2012, and to provide guidance for rational use of antibiotics. MethodsThe identification of Acinetobacter baumannii was conducted by VITEK-2 based on clinical and laboratory standards institute (CLSI) guideline between January 2008 and December 2012. The susceptibility of antibiotics was determined by K-B test, and data analysis was conducted by Excel and SAS. ResultsA total of 3 139 stains of Acinetobacter baumannii were isolated from 2013 patients during this period. The Acinetobacter baumannii was mainly obtained from the Burn ward, Intensive Care Unit ward and Thoracic ward. Sputum was the most specimens of Acinetobacter baumannii, accounting for 48.4%. The drug resistance rates of Acinetobacter baumannii to most of the antimicrobial agents were more than 55%. Compound antibacterial is more effective than the single drug ingredient. Compared with other antimicrobial agents, β-lactams/β-lactamase inhibitor compound and carbapenems antimicrobial agents were more sensitive. ConclusionThe drug resistance of Acinetobacter baumannii is serious and has differences among hospitals. Clinicians should monitor the drug resistance of Acinetobacter baumannii timely and choose proper antibiotics according to the results of drug sensitivity.
Objective To evaluate the clinical effects and safety of polymyxin B on ventilator-associated pneumonia caused by pandrug-resistant Acinetobacter baumannii (PDR-AB) in patients with chronic obstructive pulmonary disease (COPD). Methods COPD patients who were diagnosed as ventilator-associated pneumonia caused by PDR-AB and treated with polymyxin B between January 2015 and August 2016 in this hospital were included in this retrospective study. The patients’ symptoms, vital signs, and the results of laboratory examinations were recorded before and after treatment. The clinical cure rates, microbiological eradication rates, mortality and safety were also measured. Results A total of 11 cases were included in this study. Mean time of therapy was 10 days, ranged 8-13 days. After treatment with polymyxin B, most of the patients’ clinical symptoms, signs, and results of laboratory tests as well as imaging examinations were significantly improved. Seven cases had clinical response, and the clinical efficacy rate was 63.6%; 8 cases achieved bacteriological eradication, with the bacteriological eradication rate of 72.7%. Four patients died, and the overall mortality was 36.4%. Only 1 case discontinued treatment with polymyxin B because of the drug fever. Conclusions Polymyxin B might be an alternative option for COPD patients with ventilator-associated pneumonia caused by PDR-AB, who is non-responder to prior antimicrobial therapy. However, this method should be evaluated cautiously in prospective well-controlled studies.
Intracranial Acinetobacter baumannii infection is a rare clinical disease with a gradual increase in incidence and extremely high mortality. With the continuous enhancement of bacterial resistance, more and more intracranial infections of multidrug-resistant and extensively drug-resistant Acinetobacter baumannii have appeared in the clinic, and its treatment has become a major challenge and problem faced by neurosurgeons. The treatment difficulties include the selection, usage and dosage of antimicrobial agents, as well as whether cerebrospinal fluid drainage is needed. A standardized treatment plan is still needed. In this paper, combining domestic and foreign literature, the treatment of intracranial infection of multidrug-resistant and extensively drug-resistant Acinetobacter baumannii will be reviewed in order to provide a reference for clinical treatment.