Abstract

Introduction

Corynebacterium striatum has emerged as a significant nosocomial pathogen, particularly among intensive care unit (ICU) patients. This study aimed to determine whether Corynebacterium striatum isolated from respiratory samples represents true infection or colonization and to identify risk factors distinguishing these conditions.

Materials and Methods

We conducted a retrospective cohort study from June 2015 to June 2025, including adult ICU patients with Corynebacterium striatum isolated from respiratory specimens. Patients were classified into pneumonia or colonization/contamination (CC) groups. Risk factors were analyzed using descriptive statistics, univariate comparisons, and multivariate binary logistic regression to identify independent predictors of pneumonia.

Results

Among 396 patients, 126 (31.8%) were classified in the pneumonia group and 270 (68.2%) in the CC group. Chronic obstructive pulmonary disease (COPD; 31% vs. 2.2%, p < 0.001) and cardiovascular disease (22.2% vs. 11.5%, p = 0.005) were more prevalent in the pneumonia group. Multivariate analysis identified COPD (adjusted odds ratio [OR] = 26.67; 95% confidence interval [CI] = 5.05–140.91; p < 0.001) and Bartlett score (adjusted OR = 20.61; 95% CI = 10.99–38.61; p < 0.001) as independent predictors of pneumonia. The area under the receiver operating characteristic curve for the Bartlett score was 0.941 (95% CI = 0.914–0.968); a score ≥1 had 92% sensitivity and 93% specificity for predicting pneumonia.

Conclusion

Isolation of Corynebacterium striatum from respiratory samples in ICU patients should not be automatically dismissed as contamination, particularly in patients with COPD or specimens with higher Bartlett scores. Assessment of specimen quality provides valuable diagnostic insight, and ongoing surveillance of antimicrobial resistance remains essential.