# P-907. Management of Corynebacterium striatum Deep-Seated Infections Across the Veterans Affairs Health Care System

## TL;DR

This study examines the best treatments for deep infections caused by Corynebacterium striatum in veterans, finding that reliable antibiotics reduce treatment failure.

## Contribution

The study provides evidence that using antibiotics with reliable activity against C. striatum improves clinical outcomes in deep-seated infections.

## Key findings

- Treatment with reliable antibiotics (e.g., vancomycin) was associated with significantly lower treatment failure rates.
- Cohorts receiving variable or no activity antibiotics had higher failure rates compared to the reliable antibiotic group.
- Surgical source control with short-term antibiotics also showed high treatment failure rates.

## Abstract

Corynebacterium striatum is frequently isolated from deep tissue cultures, yet its clinical significance and optimal treatment remain uncertain.

This was a retrospective cohort study of all patients in the Veterans Affairs Health Care System treated for C.striatum or non-speciated Corynebacterium isolated from ≥ 1 deep tissue culture between 1 January 2013 and 30 September 2022. Patients were assigned to 1 of 4 cohorts: 1) > 7 days treatment with a reliable agent (vancomycin, linezolid, tedizolid, lipoglycopeptide), 2) > 7 days treatment with an agent possessing variable activity (daptomycin, aminopenicillins [±β-lactamase inhibitor], doxycycline, minocycline, sulfamethoxazole-trimethoprim), 3) > 7 days treatment of an agent with no activity (all other antibiotics), and 4) definitive surgical source control with ≤ 7 days of antibiotics. The primary composite outcome was clinical failure, defined as microbiologic recurrence or antibiotic failure within 6 months, unplanned surgical procedure within 12 months, or 12-month all-cause mortality.

A total of 120 patients met inclusion criteria. Notable differences in baseline characteristics were ID consultation (94.9%, 82.1%, 77.3%, 40%), polymicrobial infection (56.4%, 76.9%, 54.5%, 45%), and C.striatum isolated (76.9%, 89.7%, 86.4%, 90%) in cohorts 1-4, respectively. Vancomycin was the most used antibiotic in cohort 1 at 82.1% followed by linezolid at 25.6%. Aminopenicillins (±β-lactamase inhibitor) were the most used antibiotic in cohort 2 at 41% followed by daptomycin at 35.9%.

Treatment failure occurred in 33.3% (13/39), 61.5% (24/39), 45.5% (10/22), and 65% (13/20) of patients in cohorts 1-4, respectively (p=0.018). When directly comparing cohort 1 against each individual cohort, treatment failure was significantly higher in cohorts 2 and 4 (p=0.019 and p=0.008, respectively). Multivariable analysis revealed receipt of a cohort 1 antibiotic was independently associated with a lower odds of treatment failure (OR 0.19, 95% 0.052-0.693). No other factors tested were associated with treatment failure.

For deep-seated C.striatum and non-speciated Corynebacterium infections, treatment with reliable antibiotics was significantly associated with reduced risk of treatment failure.

All Authors: No reported disclosures