Microbiological and Clinical Characteristics of Bloodstream Infections in General Intensive Care Unit: A Retrospective Study

A Retrospective Observational Study of the Microbial Etiology and Antimicrobial Susceptibility Patterns of Blood Cultures From ICU Patients at a Healthcare Facility in North India

Introduction Bloodstream infections (BSI) are a leading source of fatalities and morbidity in hospitals. However, the clinical spectrum and antimicrobial resistance differ globally. Identifying the pathogenic spectrum and variations in antibiotic resistance is crucial for controlling BSI and preventing inappropriate antibiotic use. Material and methods This retrospective observational study was conducted at the Dr. Ram Manohar Lohia Institute of Medical Sciences, Lucknow, UP, India, for one year between June 2022 and June 2023. A total of 669 adult patients' blood cultures were obtained from ICUs. Blood culture was done using a BacT/Alert 3D (BioMérieux SA, Marcy-l'Étoile, France) automated system. Identification of the bacterial as well as fungal isolates was done using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS), and the antimicrobial susceptibility profile was analyzed using the VITEK 2 Compact system (BioMérieux SA). Results Of the 669 blood culture samples, 213 (31.8%) showed bacterial or fungal growth. Of these 213 isolates, the most common isolate was coagulase-negative Staphylococci (21.6%), followed by Klebsiella pneumoniae (19.3%) and Acinetobacter spp. (17.8%). The majority of gram-negative bacteria were resistant to most drugs, and vancomycin and linezolid were both effective against the majority of gram-positive bacteria. Conclusion The current study found that septicemia was more frequently caused by gram-negative bacteria than by gram-positive bacteria. Blood cultures are always necessary in cases of suspected septicemia, and once the antimicrobial susceptibility profile of the pathogen causing septicemia has been determined, suitable antimicrobials should be prescribed and used to lower the antimicrobial resistance burden.

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

OBJECTIVE

Acinetobacter baumannii is one of the most important pathogenic bacteria causing nosocomial infections and has a high mortality rate. Assessment of the microbiological characteristics and risk factors on prognosis associated with A.baumannii is essential. In this study, we aimed to investigate the clinical characteristics and prognostic risk factors of patients with A.baumannii bacteremia.

PATIENTS AND METHODS

This study retrospectively analyzed the antibiotic resistance of pathogens based on the clinical data of A.baumannii bacteremia patients presented in a tertiary teaching hospital from 2017 to 2022. Logistic regression and decision tree identified the prognostic risk factors for patients with baumannemia. Kaplan-Meier method was used for survival analysis between MDR and Non-MDR groups. The area under receiver-operating characteristic curve (ROC curve) was used to compare the predictive value of the APACHE II score and Sequential Organ Failure Assessment (SOFA) score.

RESULTS

A total of 110 patients with positive A. Baumannii blood cultures were included. Most of the patients were from intensive care unit (ICU) wards. The drug sensitivity results showed that the resistance rate of A. baumannii to colistin was the lowest (1.1%), followed by tigecycline (3.6%).The survival time of MDR group was significantly shorter than that of Non-MDR group. Multivariate analysis showed that, APACHE II score and SOFA score were independent risk factors affecting the prognosis of 28 days of A.baumannii bacteremia. And both scores displayed excellent AUROCs (SOFA: 0.909, APACHE II: 0.895 in predicting 28-day mortality). The two scoring systems were highly correlated and predicted no significant difference (r 2 = 0.4410, P < 0.001). We found that SOFA > 7 and APACHE II > 21 are associated with significantly higher mortality rates.

CONCLUSION

A.baumannii bacteremia have the highest incidence in the ICU, with high drug resistance and mortality rates. The survival time of patients with MDR A. Baumannii bacteremia was significantly shortened. The SOFA score and APACHE II score can reflect the severity of A.baumannii bacteremia patients and evaluate the 28-day prognosis. In addition, for the convenience of calculation, the SOFA score may be more clinically useful than the APACHE II score in predicting the mortality rate of A.baumannii bacteremia.