Objective
To investigate the clinical characteristics and bacterial drug resistance of bloodstream infection of gram-negative bacteria, and provide guidance for clinical rational drug use and control of hospital infection.
Methods
A retrospective analysis was conducted in the patients diagnosed as severe pneumonia with blood culture of gram-negative bacteria from January 2015 to December 2017 in Beijing Anzhen Hospital.
Results
A total of 60 severe pneumonia patients suffered from bloodstream infection of gram-negative bacteria were recruited including 34 males and 26 females aging from 42 to 89 years and 73.4 years in average. In the 60 patients, 32 cases were infected with Klebsiella pneumonias, 20 cases were infected with Acinetobacter baumanni, and 8 cases were infected with Escherichia coli. The antimicrobial susceptibility testing result of Klebsiella pneumonias showed that the drug susceptibility rate was 100% to tigecycline, and 6.3% to amikacin. Escherichia coli was sensitive to Amikacin, imipenem, ceftazidime and meropenem while resistance to other drugs. The antimicrobial resistance of Acinetobacter baumanni was 28.6% for cefoperazone/sulbactam, and 14.3% for tigecycline. C-reactive protein, procalcitonin and SOFA scores were higher in the patients infected with Acinetobacter baumanni. Neutrophils and blood lactic acid were higher in the patients infected with Klebsiella pneumonias. There were no statistical differences in white blood cell, platelet or motality rate between the patients infected with Acinetobacter baumanni and the patients infected with Klebsiella pneumonias. SOFA scores and blood lactic acid had significantly statistical relevance with prognosis.
Conclusion
There is a high proportion of drug resistance of Klebsiella pneumoniae and Acinetobacter baumanni in the bloodstream infection of gram-negative bacteria.
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 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.
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.
ObjectiveTo explore the prognostic risk factors of bloodstream infections caused by Acinetobacter baumannii in the hospital, to provide a basis for clinical diagnosis and treatment.MethodsA retrospective analysis was performed on the medical records of patients diagnosed with Acinetobacter baumannii bloodstream infection in Guangxi Zhuang Autonomous Region People’s Hospital between January 2013 and December 2018. The patients were divided into survival group and non-survival group according to the outcome within 30 days after blood culture was collected. Univariate and multivariate logistic analyses were used to identify the risk factors of Acinetobacter baumannii bloodstream infections.ResultsA total of 123 patients were included, including 48 in the survival group and 75 in the non-survival group. Third generation cephalosporins [odds ratio (OR)=2.492, 95% confidence interval (CI) (2.125, 2.924), P<0.001], carbapenems [OR=1.721, 95%CI (1.505, 1.969), P<0.001], multidrug resistant-Acinetobacter baumannii infection [OR=1.240, 95%CI (1.063, 1.446), P=0.006], post-operation [OR=0.515, 95%CI (0.449, 0.590), P<0.001], mechanical ventilation [OR=1.182, 95%CI (1.005, 1.388), P=0.043], indwelling central venous catheter [OR=0.116, 95%CI (0.080, 0.169), P<0.001], mixed infection or septic shock [OR=3.935, 95%CI (2.740, 5.650), P<0.001], APACHE Ⅱ score (≥15) [OR=5.939, 95%CI (5.029, 7.013), P<0.001], chronic kidney disease [OR=1.440, 95%CI (1.247, 1.662), P<0.001], immune system disease [OR=28.620, 95%CI (17.087, 47.937), P<0.001], use of corticosteroids [OR=0.520, 95%CI (0.427, 0.635), P<0.001], and combined antifungal agents [OR=0.814, 95%CI (0.668, 0.992), P=0.041] were independent factors for predicting the prognosis of patients with bloodstream infections caused by Acinetobacter baumannii.ConclusionsThe third generation cephalosporins, carbapenem, MDR-Acinetobacter baumannii infection, post-operation, mechanical ventilation, indwelling central venous catheter, mixed infection or septic shock, APACHE Ⅱ score (≥15), chronic kidney disease, immune system disease, use of corticosteroids, and combined antifungal agents were independent factors for predicting the prognosis of patients with bloodstream infections caused by Acinetobacter baumannii. In the clinical work, it is needed to carry out timely detection of microbial etiology, timely report, and reasonable treatment.
Objective To study the risk factors and prognosis of hospital acquired pneumonia( HAP)caused by carbapenem-resistant Acinetobacter baumannii( CRAB) . Methods By a case-control study, the data of 44 cases of HAP caused by CRAB fromJan 2005 to Dec 2007 in Nanfang Hospital were analyzed. 66 cases of HAP caused by Carbapenem-susceptible A. baumannii ( CSAB) were selected randomly at the same time as control. Univariate analysis( T test and chi-square test) and multivariate logistic regression were used for statistics analysis. Results Univariate analysis revealed that five factors associated with the infection caused by CRAB were APACHE Ⅱ score ≥ 16, chronic pulmonary disease ( COPD/ bronchiectasis ) , imipenem/meropenem and fluoroquinolone used 15 days before isolation of CRAB, and early combination therapy of antibiotics. Multivariate logistic regression analysis identified two independent factors as APACHEⅡ score ≥16( OR=6. 41, 95% CI 2. 20-18. 67) and imipenem/meropenemused 15 days before isolation of CRAB( OR =6. 33,95% CI 1. 83-21. 87) . Of 44 cases of CRAB infections, 14 patients died and 30 patients survived. Univariate analysis revealed that two factors associated with poor prognosis were organ failure and clinical pulmonary infection score( CPIS) rise after three-day treatment. According to multivariate logistic regression analysis, only CPIS rise after three-day treatment ( OR =7. 01, 95% CI 1. 23-40. 03) was an independent predictive factor. Conclusions APACHEⅡ score ≥ 16 and imipenem/meropenem used 15 days before isolation of CRAB were independent risk factors for CRAB infection. CPIS rise after three-day treatment was a predictive factor for the prognosis of CRAB infection.
ObjectiveTo detect the in vitro susceptibility of common clinical multidrug-resistant bacteria to tigecycline by disk diffusion (KB), minimum inhibitory concentrations (MIC) test strip (MTS) and Vitek 2 Compact methods, in order to evaluate the accuracy of the three different susceptibility testing methods.
MethodsA total of 140 multidrug-resistant isolates (excluding Pseudomonas aeruginosa) were collected retrospectively from West China Hospital between January 2014 and March 2015. The inhibitory zone diameters and MIC of tigecycline were determined by KB, Vitek 2 Compact system and MTS respectively. The results of Vitek 2 Compact system and KB method were compared with that of MTS.
ResultsAmong the 140 multidrug-resistant isolates, 119 were Acinetobacter baumannii, and 21 were Enterobacteriaceae. According to the US Food and Drug Administration standards, the sensitivity rates of 119 Acinetobacter baumannii isolates to tigecycline were 88.2%, 85.7%, and 90.8% respectively for KB method, Vitek 2 Compact system and MTS, and those of 21 Enterobacteriaceae were 76.2%, 81.0%, and 81.0%, respectively.
ConclusionsTigecycline displays effective in vitro antibacterial activity to clinical common multidrug-resistant bacteria (excluding Pseudomonas aeruginosa), but different susceptibility testing methods have shown different susceptibility rates. For Acinetobacter baumannii, KB method is superior to Vitek 2 Compact system, and for Enterobacteriaceae, Vitek 2 Compact system is superior to KB method.
Objective To evaluate the efficacy and safety of colistin in the treatment of severe infections. Methods PubMed, ISI Web of Knowledge and Wanfang databases were searched. The initial literatures and references listed in the literature were manually searched. Controlled studies were analyzed using RevMan 5. 0 software.Results Eleven studies were enrolled, including five prospective studies and six retrospective studies. Pooled analysis showed that, compared with other therapies, treatment with colistin in severe infections did not improve 28 or 30-day mortality, clinical symptoms, or bacteria clearance,however, increased the risk of kidney damage. Subgroup analysis showed that colistin did not improve symptoms, mortality ( which was even higher in the patients with drug resistant bacteria infection) , or kidney damage in drug resistant bacteria infections and ventilator associated pneumonia ( VAP) compared with the other antibiotic group. Conclusions Colistin is not superior to the other antibiotics in severe infections.However, there are some shortcomings in our meta-analysis due to limited high-quality RCTs, thus welldesigned RCTs are still needed before final conclusion is made.
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.
