Impact of Rapid Pathogen Identification of Gram-Negative Anaerobes on Antimicrobial Stewardship

Presenter: Khankan, Nour

This retrospective pre-/post-intervention study across 14 hospitals evaluated the impact of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) for rapid identification of anaerobic gram-negative bacteria directly from positive blood culture broth (PBCB). A total of 605 patients were included (197 pre-intervention, 408 post-intervention), comparing conventional methods vs direct MALDI-TOF testing.

In monomicrobial bloodstream infections, MALDI-TOF significantly reduced time to pathogen identification from 45.3 to 15.0 hours (p<0.001). In a secondary cohort (n=200), time to antibiotic de-escalation was also significantly shorter (52.0 vs 21.1 hours, p=0.014). No significant differences were observed in time to antibiotic escalation.

These findings demonstrate that direct MALDI-TOF MS enables faster pathogen identification and earlier antibiotic optimization, particularly de-escalation, supporting its role in improving antimicrobial stewardship for anaerobic bloodstream infections.

Evaluation of a Broad-Spectrum Antibiotic Monitoring Tool Across a Large Academic Hospital System

Presenter: Fal, Victoria

This quality improvement study evaluated pharmacist compliance with documentation requirements for broad-spectrum antibiotic (BSA) use within the Yale New Haven Health System. Pharmacists receive electronic alerts for BSA use beyond 48 hours or expiring orders and are expected to document assessments using a standardized template to support antimicrobial stewardship.

Fifty patient charts (October 1–November 15, 2024) were reviewed across five delivery networks. Template compliance was low at 30%, while overall documentation compliance was high at 96%. Pharmacists performed stewardship interventions in several cases, including discontinuation of antibiotics in 11 patients (22%) and de-escalation in 7 patients (14%). Antibiotics were continued in 32 patients (64%) due to appropriate use or need for additional information.

While overall pharmacist documentation for broad-spectrum antibiotic use was high, adherence to the standardized template was low, highlighting an opportunity to improve consistency in antimicrobial stewardship practices despite active and appropriate clinical interventions.

Deadly Lines: The Critical Need for Early Detection

Presenter: Gill, Kamalpreet

This case report describes a rare presentation of Gram-negative hemodialysis (HD) catheter-related infection without concurrent bacteremia. A 46-year-old man with autosomal dominant polycystic kidney disease and end-stage renal disease on HD presented with recurrent high-grade fevers (up to 104°F) and flu-like symptoms occurring during dialysis sessions over one month. His history included Enterococcus faecalis bacteremia and right subclavian DVT.

On evaluation, he had a fever of 103.1°F and persistent myalgia but no leukocytosis, and the catheter site appeared clean. Extensive investigations—including chest X-ray, CT abdomen/pelvis, viral panel, urinalysis, transthoracic echocardiogram, and blood cultures—were negative. Fever temporarily resolved with acetaminophen.

Given persistent symptoms, HD catheter tip culture was performed, yielding <15,000 colonies of Enterobacter cloacae. Following catheter removal, the patient’s symptoms resolved completely, repeat cultures were negative, and a new catheter was placed. He received 3 days of Zosyn and vancomycin, with no further antibiotics, and was discharged without recurrence.

This case highlights that catheter-related infections with Gram-negative organisms can occur without bacteremia and may require a high index of suspicion, particularly in patients with prior bacteremia or thrombosis.

Effect of Rapid Sepsis Test Adoption on Mortality, Discharge, Hospital-Free Days and Cultures In 4 EDS

Presenter: Thomas, Christopher

This quality improvement study assessed the impact of integrating a host response (HR) test into emergency department (ED) triage for suspected infection across four sites: Gonzales, LA (S1), Lafayette, LA (S2), Jackson, MS (S3), and Monroe, LA (S4).  A total of 13,972 encounters were included: S1 (n=1966; 14%), S2 (n=3009; 22%), S3 (n=4911; 35%), and S4 (n=4086; 29%). Among tested patients, 11,228 were non-septic and 2,744 (19.6%) were septic.

Following implementation, mortality decreased in both groups—non-septic: 10.9% (149/1368) to 7.3% (253/3639), and septic: 30.6% (107/350) to 22.7% (154/679) (post-implementation, Q3). ED discharge rates improved among non-septic patients from 18.3% (250/1368) to 24.5% (892/3639) (Q3), with no change in ED return rates. Return-adjusted hospital-free days increased from 28 to 30 days in non-septic patients and from 24 to 28.5 days in septic patients (post, Q3). Blood culture utilization decreased by 14% (51% [697/1368] pre vs 37% [1342/3639] post, Q3).

Overall, integration of HR testing into ED triage was associated with improved mortality, increased ED discharge rates, more hospital-free days, and reduced diagnostic resource utilization.

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