Microbiological characteristics and risk factors on prognosis associated with Acinetobacter baumannii bacteremia in general hospital: A single-center retrospective study

Dynamic monitoring of neutrophil/lymphocyte ratio, APACHE II score, and SOFA score predict prognosis and drug resistance in patients with Acinetobacter baumannii-calcoaceticus complex bloodstream infection: a single-center retrospective study

Objective

This study aimed to evaluate the clinical value of dynamic monitoring of neutrophil/lymphocyte ratio (NLR), APACHE II (Acute Physiology and Chronic Health Evaluation II) score, and Sequential Organ Failure Assessment (SOFA) score in predicting 28-day prognosis and drug resistance in patients with bloodstream infection with Acinetobacter baumannii-calcoaceticus complex (Abc complex).

Patients and methods

In this research, individuals admitted to Tianjin Medical University General Hospital from January 2017 to March 2023 with bloodstream infections and a minimum of one Abc complex positive blood culture were chosen. The risk factors for the 28-day prognosis and drug resistance were analyzed using logistic regression. The NLR, APACHE II score, and SOFA score were evaluated for predicting 28-day prognosis and drug resistance using an ROC curve analysis. The data were analyzed using R Studio to find correlations and conduct survival analysis with the Kaplan-Meier method.

Results

The final statistical analysis included a total of 129 patients with bloodstream infections caused by Abc complex. Independent risk factors predicting mortality within 28 days were identified as follows: the SOFA score and APACHE II scores at 24 h, and APACHE II scores at 72 h after the onset of blood infection (p < 0.05). NLR, SOFA score, and APACHE II score did not predict drug resistance. Patients with Carbapenem-resistant Acinetobacter baumannii-calcoaceticus complex (CRAB) had shorter survival times than those with carbapenem-sensitive strains (40.77 days vs. 47.65 days, respectively, p = 0.0032).

Conclusion

The prognosis of Abc complex bloodstream infection is affected by both SOFA and APACHE II scores. Both scoring systems have similar prognostic values at different time points after infection, but for computational convenience, it is recommended to use the SOFA score. NLR exhibits limited effectiveness in predicting mortality within 28 days. Carbapenem-resistant individuals with Abc complex experience significantly reduced survival time. None of the three factors-SOFA score, APACHE II score, and NLR-can early predict the occurrence of CRAB infections effectively.

Acinetobacter baumannii infection in intensive care unit: analysis of distribution and drug resistance

BACKGROUND

The isolation rate and drug resistance rate of Acinetobacter baumannii (A.baumannii) have increased over the years, which has become one of the main causes of infection and death in intensive care unit (ICU) patients. Analysis of the distribution characteristics, drug resistance and influencing factors of A.baumannii in ICU could provide basis and reference for the infection prevention and clinical treatment.

METHODS AND RESULTS

In this study, patients diagnosed with A.baumannii infection in ICU from January 2020 to December 2021 were selected. Samples of patients were collected for bacterial culture, drug sensitivity test analysis and drug resistant gene detection of A.baumannii. A total of 197 strains of A.baumannii were cultured in 2021, which was 18 strains more than in 2020. The specimens were mainly from lower respiratory tract secretions, and the isolated strains were multi-drug resistant. The resistance of isolates to tobramycin, gentamicin, and trimethoprim-sulfamethoxazole in 2021 showed a significant increase compared to 2020, while there were no significant differences observed in other resistance changes. The prevalence of multi-drug resistant A.baumannii in ICU remains high. Among them, all imipenem-resistant A.baumannii strains carried OXA-23 gene.

CONCLUSION

Clinical treatment should use antibiotics reasonably based on the characteristics of bacterial resistance, and strengthen the prevention and control of hospital infection, pay more attention to the disinfection and isolation to reduce the risk of cross infection.

Insights into the epidemiology, risk factors, and clinical outcomes of carbapenem-resistant Acinetobacter baumannii infections in critically ill children

Background and aims

Carbapenem-resistant Acinetobacter baumannii (CRAB) has become a leading cause of nosocomial infections with an increasing impact on critically ill patients, yet there is limited data on contributing factors. This study was aim to evaluate the prevalence and risk factors, and clinical outcomes of CRAB infections among critically ill children in a tertiary university teaching hospital in China.

Methods

From January 2016 to December 2021, all children diagnosed with nosocomial Acinetobacter baumannii (A. baumannii) infections in the pediatric intensive care unit (PICU) were identified through the computerized microbiology laboratory databases. Among them, children suffering from CRAB infection were designated as a case group, while children with carbapenem susceptible A. baumannii (CSAB) infection were assigned to a control group. This retrospective case-control study was based on two groups of patients to determine potential clinical factors contributing to CRAB infection and death among critically ill children via univariate and multivariate analyses.

Results

During the 6-year study period, a total of 372 episodes of nosocomial A. baumannii infection in the PICU were eligible and included in the study. These isolates displayed moderate or high rates of resistance to all tested antimicrobials except colistin. The overall prevalence of CRAB and MDRAB (multidrug-resistant A. baumannii) was 78.0% and 80.9%, respectively. Several risk factors found to significantly increase CRAB infection included receiving invasive operation (OR = 9.412, p = 0.001), gastric intubation (OR = 2.478, p = 0.026), prior carbapenems exposure (OR = 2.543, p = 0.003), severe pneumonia (OR = 3.235, p = 0.001), and hemoglobin <110g/L (OR = 3.049, p = 0.005). Of 372 patients with CRAB infection, the mortality rate was 30.9% (115/372) and mortality did not differ between children with CRAB and CSAB infections. Septic shock (OR = 2.992, p = 0.001), AST > 46U/L (OR = 2.015, p = 0.005), bone marrow aspiration (OR = 2.704, p = 0.008), lymphocyte <20 % (OR = 1.992, p = 0.006) and age (OR = 1.094, p = 0.002) were independent risk factors for the death of A. baumanni infection.

Conclusions

This study highlights considerable incidence rate and remarkable mortality of children with A. baumanni (especially CRAB) infections, and identifies age-specific risk factors for CRAB infection and mortality in critically ill children. These risk factors should be taken into account in pediatric hospitals in order to establish early intervention and rational treatment to improve clinical outcomes.