Multidrug-resistant Acinetobacter Baumannii Pneumonia Research Articles

Retracted: Polymyxin B, Cefoperazone Sodium-Sulbactam Sodium, and Tigecycline against Multidrug-Resistant Acinetobacter baumannii Pneumonia.

[This retracts the article DOI: 10.1155/2022/1968020.].

Sulbactam combined with tigecycline improves outcomes in patients with severe multidrug-resistant Acinetobacter baumannii pneumonia

BackgroundThe purpose of this study was to review the treatment plan of patients with multidrug-resistant Acinetobacter baumannii (MDR-AB) pneumonia and analyze the factors associated with patient deaths and the medication regimen.MethodsWe collected 1,823 qualified respiratory specimens that were culture-positive for MDR-AB. 166 patients confirmed to have hospital-acquired MDR-AB pneumonia were selected as the research subjects. The differing clinical characteristics and treatment interventions between the surviving group and death group within 28 days were analyzed.ResultsThe mortality rate was high for those aged > 75 years (p = 0.001). Patients who underwent invasive catheter placement (p < 0.001) and mechanical ventilation (p = 0.046) had a higher mortality rate. Combination therapy with tigecycline can reduce the mortality rate (p < 0.001) of MDR-AB pneumonia in patients with carbapenem-resistant AB(CRAB). Combination therapy with sulbactam was shown to reduce the mortality rate (p < 0.001), and high-dose sulbactam (> 3 g/day) might be better than low-dose sulbactam (≤ 3 g/day).ConclusionReducing the time of invasive catheter placement and mechanical ventilation in patients in the intensive care unit (ICU), antimicrobial treatment, combined with tigecycline and sulbactam, might help reduce the mortality rate in patients with severe MDR-AB hospital-acquired pneumonia.

Alert Germ Infections: Chest X-ray and CT Findings in Hospitalized Patients Affected by Multidrug-Resistant Acinetobacter baumannii Pneumonia.

Acinetobacter baumannii (Ab) is an opportunistic Gram-negative pathogen intrinsically resistant to many antimicrobials. The aim of this retrospective study was to describe the imaging features on chest X-ray (CXR) and computed tomography (CT) scans in hospitalized patients with multidrug-resistant (MDR) Ab pneumonia. CXR and CT findings were graded on a three-point scale: 1 represents normal attenuation, 2 represents ground-glass attenuation, and 3 represents consolidation. For each lung zone, with a total of six lung zones in each patient, the extent of disease was graded using a five-point scale: 0, no involvement; 1, involving 25% of the zone; 2, 25–50%; 3, 50–75%; and 4, involving >75% of the zone. Points from all zones were added for a final total cumulative score ranging from 0 to 72. Among 94 patients who tested positive for MDR Ab and underwent CXR (males 52.9%, females 47.1%; mean age 64.2 years; range 1–90 years), 68 patients underwent both CXR and chest CT examinations. The percentage of patients with a positive CT score was significantly higher than that obtained on CXR (67.65% > 35.94%, p-value = 0.00258). CT score (21.88 ± 15.77) was significantly (p-value = 0.0014) higher than CXR score (15.06 ± 18.29). CXR and CT revealed prevalent bilateral abnormal findings mainly located in the inferior and middle zones of the lungs. They primarily consisted of peripheral ground-glass opacities and consolidations which predominated on CXR and CT, respectively.

Effectiveness of tigecycline-based versus colistin- based therapy for treatment of pneumonia caused by multidrug-resistant Acinetobacter baumanniiin a critical setting: a matched cohort analysis

BackgroundColistin and tigecycline have both been shown good in vitro activity among multi-drug resistant Acinetobacter baumannii (MDRAB). A comparative study of colistin versus tigecycline for MDRAB pneumonia is lacking.MethodsThe study enrolled adults with MDRAB pneumonia admitted to intensive care units at a referral medical center during 2009–2010. Since there were no standardized minimum inhibitory concentration (MIC) interpretation criteria of tigecycline against A. baumannii, MIC of tigecycline was not routinely tested at our hospital. During the study periods, MIC of colistin was not routinely tested also. We consider both colistin and tigecycline as definite treatments of MDRAB pneumonia. Patients who received tigecycline were selected as potential controls for those who had received colistin. We performed a propensity score analysis, by considering the criteria of age, gender, underlying diseases, and disease severity, in order to match and equalize potential prognostic factors and severity in the two groups.ResultsA total of 294 adults with MDRAB pneumonia were enrolled, including 119 who received colistin and 175 who received tigecycline. We matched 84 adults who received colistin with an equal number of controls who received tigecycline. The two well matched cohorts share similar characteristics: the propensity scores are colistin: 0.37 vs. tigecycline: 0.37, (P = .97); baseline creatinine (1.70 vs. 1.81, P = .50), and the APACHE II score (21.6 vs. 22.0, P = .99). The tigecycline group has an excess mortality of 16.7% (60.7% vs. 44%, 95% confidence interval 0.9% – 32.4%, P = .04). The excess mortality of tigecycline is significant only among those with MIC >2 μg/mL (10/12 vs. 37/84, P = .01), but not for those with MIC ≦ 2 μg/mL (4/10 vs. 37/84, P = .81).ConclusionsOur data disfavors the use of tigecycline-based treatment in treating MDRAB pneumonia when tigecycline and colistin susceptibilities are unknown, since choosing tigecycline-based treatment might result in higher mortality. The excess mortality of tigecycline-based group may be related to higher MIC of tigecycline (> 2 μg/mL). Choosing tigecycline empirically for treating MDRAB pneumonia in the critical setting should be cautious.

Influencing factors of successful eradication of multidrug-resistant Acinetobacter baumannii in the respiratory tract with aerosolized colistin.

The increased prevalence of multidrug-resistant Acinetobacter baumannii (MDRAB) poses a worldwide treatment challenge. Although aerosolized colistin therapy for MDRAB pneumonia has attracted increasing interest, factors influencing successful eradication remain unclear. This retrospective study evaluated 135 consecutively admitted adult patients showing positive respiratory secretion cultures for MDRAB who underwent aerosolized colistin therapy between January 2007 and November 2011. Possible factors related to pneumonia and MDRAB eradication were collected for analysis. Patients with successful MDRAB eradication on Day 14 had a shorter interval between the day the positive MDRAB sputum cultures were yielded and the day colistin inhalation treatment began (4.0 ± 2.5 vs. 7.3 ± 6.5; p = 0.002). Patients with a worsening chest X-ray on Day 7 of the colistin inhalation had a lower chance of 14-day MDRAB eradication [1/44 (2.3%) vs. 8/37 (21.6%); p = 0.006]. Patients with diabetes mellitus also had a lower chance of early MDRAB eradication [13/44 (29.5%) vs. 20/37 (54.1%); p = 0.025]. Early intervention using aerosolized colistin in patients with MDRAB pneumonia or colonization can achieve better eradication.

Acid aspiration provokes the pneumonia caused by multidrug-resistant Acinetobacter baumannii in BALB/c mice

To determine whether acid aspiration provokes the development of multidrug-resistant Acinetobacter baumannii (MDRAB) pneumonia in its host. Groups of mice were inoculated intratracheally (IT) with 50 μl of 0.1N HCl and 1 × 10(8) colony-forming units (CFU) Ab396 (A+Ab group), or 50 μl of 0.1N HCl and 20 μl of 0.9% saline (A+S group), or 20 μl of 0.9% saline and 1 × 10(8) CFU of Ab396 (S+Ab group), or 50 μl of 0.9% saline and 20 μl of 0.9% saline (S+S group). Cytokines, bacterial loads in the bronchoalveolar lavage fluid (BALF), lung permeability, histopathology of the lungs, and survival rates were evaluated. Only the A+Ab mice developed extensive Ab396 pneumonia and had significantly elevated bacterial loads, increased lung leakage, and lower levels of tumor necrosis factor alpha (TNF-α) compared with the other three groups (p<0.05, Mann-Whitney U-test). Moreover, a strong synergistic effect (p<0.05, two-way analysis of variance) was observed between the acid induction and Ab396 infection, resulting in lung injury and an unfavorable survival outcome. Lung injury caused by acid aspiration provoked secondary MDRAB pneumonia; also synergistic effects between acid aspiration and Ab396 infection resulted in a detrimental outcome in the infected mice.

Risk factors and antibiotic resistance analysis of pneumonia caused by multidrug resistant acinetobacter baumannii in pediatric intensive care unit

Objective To investigate the risk factors involved in the refractory pneumonia caused by multidrug resistant acinetobacter baumannii (MDRAb) in pediatric Intensive care unit (PICU).Methods From January 2009 to August 2011,115 patients with MDRAb pneumonia were treated in Department of Emergency,Wuhan Children's Hospital,Wuhan.Another 45 patients with negative MDRAb (NMDRAb)pneumonia served as control.The patients in the two goups were analyzed using univariate and multivariate Logistic regression to find out the risk factors for MDRAb infection.Results Among the 176 clinical strains of acinetobacter baumannii isolated,128 (72.73％) strains were MDRAb.After drug susceptibility tests,acinetobacter baumannii showed the rates of resistance to β-lactams antibiotics not including cefoperazone-sulbactam were more than 70％,and the rates of resistance to carbapenems antibiotics were higher than 90％.All rates of resistance to antibiotics of betalactams and carbapenems in MDRAb were higher than those in NMDRAb significantly.There were very low rates of drug-resistance found in Amikacin,Levofloxacin,Ciprofloxacin and Minocycline ( ＜20％ ).Multivariate logistic regression revealed that ICU stay,length of time for mechanical ventilation,anemia,hypoproteinemia and the use of carbapenems were independent risk factors involved in MDRAb pneumonia.Conclusions MDRAb was an important conditional pathogen with high rate of drug-resistance to many antibiotics leading to pneumonia in PICU.It increased the mortality of patients significantly.To control the infection of MDRAb was the key to increasing efficacy of treatment of pneumonia in PCIU. Key words: Pediatric; Intensive care unit; Multidrug resistant; Acinetobacter baumannii; Pneumonia; Risk factor; Retrospective study

Risk factors and antibiotic resistance of pneumonia caused by multidrug resistant Acinetobacter baumannii in pediatric intensive care unit.

With beta-lactam drugs and immunosuppressants widely used, the infection caused by Acinetobacter baumannii (Ab) has become more and more serious with multidrug resistant Acinetobacter baumannii (MDRAb) emerging and worsening rapidly. Compared with other patients, the incidence and multidrug resistance of MDRAb are higher in children in pediatric intensive care unit (PICU) because of immune deficiency, severe basic diseases, prolonged hospitalization and invasive operations. Hence it is significant to study the epidemiology and changes of antibacterial susceptibility in order to reduce the incidence of MDRAb in children. A total 115 patients with MDRAb pneumonia and 45 patients with negative MDRAb (NMDRAb) pneumonia who had been treated from January 2009 to August 2011 were studied retrospectively at the PICU of Wuhan Children's Hospital. Clinical data were analyzed with univariate and multivariate Logistic regression. In 176 clinical strains of Acinetobacter baumannii isolated, there were 128 strains of MDRAb, accounting for 72.73%. Drug susceptibility tests showed that the resistance rates of β-lactam antibiotics were more than 70% except for cefoperazone sulbactam. The rates to carbapenems were higher than 90%. They were significantly higher than those of NMDRAb. Amikacin, levofloxacin, ciprofloxacin and minocycline had the lowest drug-resistance rates (<20%). Multivariate Logistic regression revealed that ICU stay, the time of mechanical ventilation, anemia, hypoproteinemia and the use of carbapenems were independent risk factors for MDRAb pneumonia. MDRAb is an important opportunistic pathogen to pneumonia in PICU, and its drug-resistance is severe. It increases significantly the mortality of patients. It is important to take the effective prevention measures for controlling it.

The clinical implication and prognostic predictors of tigecycline treatment for pneumonia involving multidrug-resistant Acinetobacter baumannii

To investigate the clinical implication and prognostic predictors of tigecycline treatment for pneumonia involving multidrug-resistant Acinetobacter baumannii (MDRAB). A retrospective observational study over a 32-month period for adult patients receiving tigecycline treatment at least 7 days for pneumonia involving MDRAB. We reviewed 112 patients with 116 episodes of tigecycline-treated pneumonia involving MDRAB. The mean age was 70.8 years. The mean Acute Physiology and Chronic Health Evaluation (APACHE) II score was 21.7. Seventy episodes (60.3%) had clinical resolution. The episodes with monomicrobial MDRAB pneumonia had a significantly lower clinical resolution rate than polymicrobial pneumonia (14/31, 45.2% vs. 56/85, 65.9%; p=0.044). The independent predictors for failure of clinical resolution were female gender, malignancy, bilateral pneumonia, monomicrobial pneumonia, and higher APHCHE II scores. Forty-two episodes (36.2%) had the 30-day mortality, and the only independent predictor was deterioration of pneumonia on chest radiographs. A high disease severity, bilateral pneumonia, and monomicrobial MDRAB pneumonia predicted failure of clinical resolution, and deterioration of pneumonia predicted mortality. MDRAB in monomicrobial pneumonia was the most certain to be causal. The clinical resolution rate from such pneumonia might reflect the ultimate efficacy of tigecycline in treating MDRAB pneumonia and the overall efficacy might be overestimated.

Colistin Therapy in a 23-Week Gestational-Age Neonate with Multidrug-ResistantAcinetobacter baumanniiPneumonia

Multidrug-resistant pathogens are becoming more difficult to treat with significantly increasing infection rates. The lack of new antibiotics to combat these strains has led to the resurgence of older antibiotics. This case highlights the first reported use of colistimethate sodium treatment in a 23-week gestational-age neonate with multidrug-resistant Acinetobacter baumannii pneumonia who developed acute renal failure and seizures shortly after initiation of treatment.