Community-acquired Escherichia coli pneumonia: clinical, radiological, laboratory, and prognostic characteristics in a retrospective single-center study.

BACKGROUND

Community-acquired pneumonia (CAP) caused by Escherichia coli (E. coli) is uncommon, and its clinical features and prognosis remain insufficiently characterized.

OBJECTIVES

To compare the clinical, laboratory, radiological, and prognostic characteristics of community-acquired E. coli pneumonia (CAECP) with CAP caused by other pathogens.

DESIGN

Single-center retrospective observational cohort study.

SETTINGS: Department of Pulmonology, Kocaeli City Hospital, İzmit, Kocaeli, Türkiye from April 2023 to March 2025.

PATIENTS AND

METHODS

Adult patients hospitalized with CAP and positive sputum cultures were reviewed. Hospital-acquired and ventilator-associated pneumonias were excluded. Patients were classified as CAECP or Other-CAP. Demographic, clinical, laboratory, radiological, CURB-65, Pneumonia Severity Index (PSI), and outcome data were compared. A targeted multivariable logistic regression model adjusted for age and malignancy evaluated 90-day mortality.

MAIN OUTCOME MEASURES: In-hospital mortality, 90-day mortality, intensive care unit admission, and hospital length of stay.

SAMPLE SIZE: Sixty-eight patients (37 CAECP, 31 Other-CAP).

RESULTS

Median age (69 [interquartile range, IQR 50.7-71] vs 67 [56-70] years; P=.805), sex distribution (P=.452), comorbidity burden (P=.094), body temperature (P=.970), heart rate (P=.592), C-reactive protein (P=.731), procalcitonin (P=.749), multilobar involvement (P=.246), and air bronchogram (P=.938) were comparable between groups. Mean CURB-65 (1.73±0.90 vs 1.45±0.99; P=.253) and PSI (108.6±40.6 vs 95.4±27.6; P=.143) were also similar. Hospital stay was significantly longer in CAECP (15.7±15.5 vs 9.6±7.0) days; P=.047). In-hospital mortality was numerically higher (14% vs 0; P=.058), while 90-day mortality was significantly higher (49% vs 16%; P=.005). After adjustment for age and malignancy, CAECP remained independently associated with 90-day mortality (aOR, 7.41; 95% CI, 1.85-29.71; P=.005).

CONCLUSION

CAECP resembles other CAP etiologies at presentation, but is associated with longer hospitalization and markedly higher 90-day mortality despite similar baseline severity scores.

LIMITATIONS: Single-center retrospective design, small sample size, and limited number of mortality events.