Clinical Characteristics, Prognosis and Treatment of Bloodstream Infections with Enterobacter Cloacae Complex in a Chinese Tertiary Hospital: A Retrospective Study.

Objective: This research aimed to analyze the clinical characteristics, prognosis, and antimicrobial treatment of bloodstream infections (BSI) caused by Enterobacter cloacae complex (ECC). Methods: The clinical data of patients with bloodstream infections caused by Enterobacter cloacae complex from April 2017 to June 2023 were collected retrospectively. These data were then analyzed in subgroups based on the detection results of extended-spectrum ß-lactamase (ESBL), 30-day mortality, and the type of antimicrobial agent used (ß-lactam/ß-lactamase inhibitor combinations (BLICs) or carbapenems). Results: The proportion of ESBL-producing Enterobacter cloacae complex was 32.5% (37/114). Meanwhile, ICU admission, receiving surgical treatment within 3 months, and biliary tract infection were identified as risk factors for ESBL-producing ECC-BSI. Additionally, immunocompromised status and Sequential Organ Failure Assessment (SOFA) score ≥ 6.0 were identified as independent risk factors of 30-day mortality in patients with ECC-BSI (n = 108). Further analysis in BSI patients caused by non-ESBL-producing ECC revealed that patients treated with BLICs (n = 45) had lower SOFA scores and lower incidence of hypoproteinemia and sepsis compared with patients treated with carbapenems (n = 20). Moreover, in non-ESBL-producing ECC-BSI patients, the univariate Cox regression analysis indicated a significantly lower 30-day mortality rate in patients treated with BLICs compared to those treated with carbapenems (hazard ratios (HR) [95% CI] 0.190 [0.055-0.662], P = 0.009; adjusted HR [95% CI] 0.106 [0.013-0.863], P = 0.036). Conclusion: This study investigated the factors influencing the susceptibility to infection by ESBL-producing strains and risk factors for 30-day mortality in ECC-BSI patients. The results revealed that ESBL-negative ECC-BSI patients treated with BLICs exhibited significantly lower 30-day mortality compared to those treated with carbapenems. BLICs were found to be more effective in ECC-BSI patients with milder disease (ESBL-negative and SOFA ≤6.0).

GC-IMS facilitates identification of carbapenem-resistant Klebsiella pneumoniae in simulated blood cultures.

This study aimed to identify carbapenem-resistant Klebsiella pneumoniae (CRKP) based on changes in levels of its volatile organic compounds (VOCs) in simulated blood cultures (BCs) using the gas chromatography-ion mobility spectrometry (GC-IMS) technique. A comprehensive analysis of volatile metabolites produced by Klebsiella pneumoniae (K. pneumoniae) in BC bottles was conducted using GC-IMS. Subsequently, the released VOCs were analyzed to examine differences in VOC release between CRKP and carbapenem-susceptible Klebsiella pneumoniae (CSKP). A total of 54 VOCs were detected, of which 18 (6 VOCs found in both monomer and dimer forms) were successfully identified. The VOCs produced by K. pneumoniae in BC bottles (BacT/ALERT® SA) were primarily composed of organic acids, alcohols, esters, and ketones. The content of certain VOCs was significantly different between CRKP and CSKP after the addition of imipenem (IPM). Moreover, the inclusion of carbapenemase inhibitors facilitated the identification of carbapenemase-producing K. pneumoniae based on the variations in VOCs. This study demonstrates the utility of GC-IMS technology in identifying CRKP, and reveals that changes in VOCs are closely related to the growth and metabolism of K. pneumoniae, indicating that they can be leveraged to promote early identification of CRKP bacteremia. However, further in-depth studies and experiments are needed to validate our findings.

Comparison of bacteremic pneumonia caused by Escherichia coli and Klebsiella pneumoniae: A retrospective study.

OBJECTIVES: To compare the prognosis of bacteremic pneumonia caused by Klebsiella pneumoniae (K. pneumoniae) and Escherichia coli (E. coli) pathogens. METHODS: A retrospective analysis was carried out on the clinical data of 162 patients who were diagnosed with bacterial pneumonia caused by either K. pneumoniae or E. coli between 2016-2019. The primary outcome of the analysis was the patients' 30-day mortality rate. RESULTS: There were 82 patients in the E. coli bacteremic pneumonia (E. coli-BP) group and 80 patients in the K. pneumoniae bacteremic pneumonia (KP-BP) group. The 30-day mortality rate was 43.75% (n=35/80) in the KP-BP group and 21.95% (n=18/82) in the E. coli-BP group (p<0.001). Following the adjustment for confounding variables in 4 distinct models, the hazard ratios for the primary outcome in KP-BP were determined to be 0.70 (95% confidence interval [CI]: [0.44-1.02]) in Model 1, 0.72 (95% CI: [0.46-1.14]) in Model 2, 0.99 (95% CI: [0.57-1.73]) in Model 3, and 1.22 (95% CI: [0.69-2.18]) in Model 4. CONCLUSION: Patients diagnosed with KP-BP exhibited a similar prognosis as those diagnosed with E. coli-BP. For patients with KP-BP, the risk of mortality was significantly higher for those who were in the intensive care unit, were infected with carbapenem-resistant strains, or had a high sequential organ failure assessment score. In patients with E. coli-BP, the Pitt bacteremia score was strongly associated with the 30-day mortality rate.

Clinical Characteristics and Prognosis of Hospital-Acquired Klebsiella pneumoniae Bacteremic Pneumonia versus Escherichia coli Bacteremic Pneumonia: A Retrospective Comparative Study.

Objective: This research aimed to investigate the variations in clinical features and prognosis of HABP caused by E. coli and K. pneumoniae. We also aimed to evaluate the risk variables related to 30-day death in the investigated groups. Methods: A single-center retrospective cohort research lasting four years was performed. A total of 117 patients with HABP were involved in this research. The primary prognosis was 30-day death. Results: Among 117 patients with HABP, 60 patients were infected with K. pneumoniae (KP-HABP), and 57 patients were infected with E. coli (E. coli-HABP). A higher proportion of males, ICU admission, undergoing tracheotomy and trachea cannulation, carbapenem-resistant strains, inappropriate empirical therapy (IET), immune compromise, diabetes mellitus, and sepsis were observed in the patients with KP-HABP (all P < 0.05). Meanwhile, the median SOFA score and Pitt score were significantly (P < 0.001) higher in the KP-HABP group compared to the E. coli-HABP group. The 30-day death was 48.33% in the KP-HABP group and 24.56% in the E. coli-HABP group (P = 0.008). After adjusting for the main covariates, the hazard ratios for 30-day mortality in KP-HABP were 1.58 (95% CI:0.80-3.12), 3.24 (95% CI:1.48-7.06), 5.67 (95% CI:2.00-16.07), and 5.99 (95% CI:2.10-17.06), respectively. Multivariate logistic regression models revealed that IET, hypoproteinaemia, cerebral vascular disease (CVD), and SOFA score ≥ 5.0 were the independent risk variables for 30-day death in KP-HABP. Simultaneously, SOFA score ≥ 4.0 and Pitt score ≥ 2.0 were independent risk factors for 30-day mortality in E. coli-HABP. Conclusion: The clinical features of HABP vary depending on whether it is caused by Escherichia coli or K. pneumoniae. KP-HABP patients have higher 30-day mortality than E. coli-HABP patients. To ensure greater validity, it is necessary to further verify this conclusion using a larger sample size.

Early Lactate/Albumin and Procalcitonin/Albumin Ratios as Predictors of 28-Day Mortality in ICU-Admitted Sepsis Patients: A Retrospective Cohort Study.

BACKGROUND Lactate/albumin (LA/ALB) and procalcitonin/albumin (PCT/ALB) ratios have been implicated in predicting mortality in sepsis patients. However, their prognostic value and relationship to sepsis severity require further investigation. This retrospective study aimed to assess the prognostic value of lactate/albumin (LA/ALB) and procalcitonin/albumin (PCT/ALB) ratios in septic patients admitted to the Intensive Care Unit (ICU). MATERIAL AND METHODS A total of 340 adult sepsis patients admitted to the ICU were included in the derivation cohort. LA/ALB and PCT/ALB ratios were calculated and analyzed in relation to sepsis severity and survival status. Additionally, a validation cohort of 75 sepsis patients from another medical center was selected. RESULTS In the derivation cohort, higher LA/ALB and PCT/ALB ratios and SOFA scores were significantly associated with increased mortality (P<0.001). The LA/ALB and PCT/ALB ratios positively correlated with SOFA score. Survival analysis revealed significantly higher 28-day mortality in sepsis patients with elevated PCT/ALB (≥0.256) and LA/ALB (≥0.079) ratios upon ICU admission. The constructed prediction model incorporating LA/ALB ratio, PCT/ALB ratio, and SOFA score yielded an AUC of 0.826, demonstrating good predictive ability. The associations between LA/ALB and PCT/ALB ratios and 28-day mortality in sepsis patients were validated in the validation cohort. CONCLUSIONS The LA/ALB and PCT/ALB ratios at ICU admission provide valuable prognostic information for predicting 28-day mortality in sepsis patients. Combining these ratios with SOFA score improves the assessment of prognosis in sepsis patients.

Assessment of Effective Antimicrobial Regimens and Mortality-Related Risk Factors for Bloodstream Infections Caused by Carbapenem-Resistant Acinetobacter baumannii.

Objective: This study aimed to determine the clinical features, risk factors, and effective antimicrobial therapy for Carbapenem-resistant Acinetobacter baumannii (CRAB) bloodstream infection (BSI). Methods: This was a retrospective analysis of data from patients with CRAB bacteremia in a Chinese tertiary hospital between January 2012 and October 2021. Risk factors, predictors of 30-day mortality, and effective antimicrobial therapy for CRAB BSI were identified using logistic and cox regression analyses. Results: Data from 276 patients with Acinetobacter baumannii (AB) BSI were included, of whom 157 (56.9%) had CRAB BSI. The risk factors that were significantly associated with CRAB BSI included previous intensive care unit (ICU) stay (P < 0.001), immunocompromised status (P < 0.001), cephalosporin use (P = 0.014), and fluoroquinolone use (P = 0.007). The 30-day mortality of the CRAB BSI group was 49.7% (78/157). ICU stay after BSI (P = 0.047), sequential organ failure assessment (SOFA) score ≥10 (P < 0.001), and multiple organ failure (MOF) (P = 0.037) were independent predictors of 30-day mortality. Among antibiotic strategies for the treatment of patients with CRAB BSI, we found that definitive regimens containing cefoperazone/sulbactam were superior to those without cefoperazone/sulbactam in reducing the 30-day mortality rate (25.4% vs 53.4%, P = 0.005). After propensity score matching, we observed a significant increase in the 30-day mortality (77.8%vs 33.3%, P = 0.036) in patients receiving tigecycline monotherapy compared to those receiving cefoperazone/sulbactam monotherapy. The mortality rate of patients receiving tigecycline with cefoperazone/sulbactam was also higher than that of patients receiving cefoperazone-sulbactam monotherapy; however, the difference was not significant (28.6%vs 19.0%, P = 0.375). Conclusion: The severity of patient conditions was significantly associated with mortality in patients with CRAB BSI. Those Patients treated with cefoperazone/sulbactam had better clinical prognoses, and tigecycline should be used with caution.

Ceftazidime/Avibactam, Polymyxin or Tigecycline as a Rescue Strategy for the Treatment of Carbapenem-Resistant Klebsiella pneumoniae in Bloodstream Infection: A Retrospective Cohort Study.

Objective: To analyze the clinical characteristics, outcomes, and risk factors of patients treated with ceftazidime/avibactam, polymyxin, or tigecycline (CPT) compared with those receiving a conventional therapy (CT) (ie, imipenem, levofloxacin, or gentamicin). Methods: A single-center retrospective cohort study included patients with carbapenem-resistant Klebsiella pneumoniae bloodstream infection (CRKP-BSI) treated at one Chinese tertiary hospital between March 2012 and November 2022 was performed. Clinical characteristics, outcomes, and risk factors of patients treated with CPT or CT were compared. Predictors of 30-day mortality of patients with CRKP-BSI were also analysed in our study. Results: Among 184 recruited patients with CRKP-BSI, 39.7% (73/184) were treated with CPT, while 60.3% (111/184) were treated with CT. Compared to patients treated with CT, patients treated with CPT had worse conditions, as evidenced by a higher rate of underlying diseases and invasive procedures; however, they also had a better prognosis and lower rates of 14-day treatment failure (p = 0.024). In addition, univariate analysis and multivariate analysis showed that SOFA score [odds ratio (OR) = 1.310, 95% confidence interval (CI) 1.157-1.483; p < 0.001] and cold weather (OR = 3.658, 95% CI 1.474-9.081; p = 0.005) were independent risk factors for 30-day mortality. Conclusion: Compared to CRKP-BSI patients treated with CT, patients treated with CPT had worse conditions but better prognoses. CRKP-BSI occurred more frequently in hot weather; however, higher 30-day mortality was associated with cold weather. A randomized trial is needed to confirm these observational results.

Risk Factors for 30-Day Mortality in Patients with Bacteremic Pneumonia Caused by Escherichia coli and Klebsiella pneumoniae: A Retrospective Study.

Objective: Escherichia coli and Klebsiella pneumoniae are prevalent Gram-negative microorganisms responsible for pneumonia, as well as the primary Enterobacteriaceae pathogens causing bacteremic pneumonia. The objective of this research is to analyze the risk factors associated with bacteremic pneumonia caused by these pathogens and develop a predictive model. Patients and Methods: This retrospective investigation encompassed a cohort of 252 patients diagnosed with Escherichia coli or Klebsiella pneumoniae-induced bacteremic pneumonia between 2018 and 2022. The primary endpoint was 30-day mortality, which was analyzed using multifactorial logistic regression, nomogram construction, and Bootstrap validation. Results: Among the 252 patients diagnosed with Escherichia coli and Klebsiella pneumoniae, 65 succumbed to the disease while 187 survived. The overall 30-day mortality was found to be 25.8%. A multifactorial logistic regression analysis revealed that diastolic blood pressure, cerebrovascular diseases/transient ischemic attacks (TIA), immunosuppression, blood urea nitrogen, Pitt score, and CURB-65 score were statistically significant factors. The Nomogram model demonstrated an AUC of 0.954, which closely aligns with the Bootstrap-derived mean AUC of 0.953 (95% CI: 0.952-0.954). Conclusion: In patients with bacteremic pneumonia caused by Escherichia coli and Klebsiella pneumoniae, Low diastolic blood pressure (≤61 mmHg), pre-existing cerebrovascular disease/ transient ischemic attacks (TIA), immunosuppression status, elevated blood urea nitrogen levels (≥8.39 mmol/L), high Pitt score (≥3), and a high CURB-65 score (≥2) are all independent risk factors for Escherichia coli and Klebsiella pneumoniae bacteremic pneumonia, among which the first three warrant particular attention.