Loss of Independence following Necrotizing Soft Tissue Infections in Older Adults

Authors:
Manuel Castillo-Angeles, Avery Thompson, Reza Askari

Body of Abstract:
Background: There is a growing shift in benchmarking for older adult care toward metrics that capture outcomes of greatest importance to this cohort. Loss of independence (LOI), which is a composite outcome used to identify patients who are no longer able to live independently post-operatively, has been introduced as a key patient-centered outcome among older adults. However, this hasn’t been fully studied in the necrotizing soft tissue infections (NSTI) population. Our objective was to identify predictors of LOI among NSTI patients.

 

Methods: The American College of Surgeons National Surgical Quality Improvement Project database (2021-2023) was queried for older adults with a diagnosis of NSTI, which included necrotizing fasciitis, gas gangrene, and Fournier’s gangrene. Our primary outcome was LOI, defined as a decline in functional status, or an increase in care needs (patients discharged to a non-home destination or who needed new support or skilled services at home). Multivariable logistic regression was used to determine factors associated with LOI.

 

Results: We included 232 older adults with NSTI, mean age was 77.83 (SD 6.14) years, 39.22% were female, and 70.33% were White. 124 (53.45%) experience loss of independence. 

After adjusted analysis, significant predictors of LOI were age >=85 years (Odds Ratio [OR] 1.63, 95% Confidence Interval [CI] 1.60–2.09), frailty status (OR 11.17, 95%CI 5.65–16.57), history of dementia or cognitive impairment (OR 5.62, 95%CI 2.43–8.82), and postoperative length of stay (OR 1.21, 95%CI 1.01–1.45). 

 

Conclusions: More than half of older adults with a diagnosis of NSTI experienced loss of independence. LOI could be used as a marker to identify patients who require closer post-discharge monitoring. Further work should focus on targeted interventions that reduce the risk of postoperative LOI in this vulnerable population.

Microbiology of Mesh Infections after Ventral Hernia Repair

Authors:
Coleman Miller, Edwin George Mathew, Dalya Ferguson, Julie Holihan, Thomas Clements, Jonah Stulberg

Body of Abstract:
Background

More than 600,000 ventral hernia repairs are performed in the United States annually. While rare, mesh infection is a devastating complication for patients which can result in years of painful surgeries and recurring hospitalizations. Despite the significance of this problem, there is very little data regarding the current microbiology of mesh infections. Previous studies have suggested that methicillin-resistant staphylococcus aureus (MRSA) is responsible for more than 50% of mesh infections, however with changing mesh types and the increasing use of minimally invasive techniques, we sought to determine the current microbiology of mesh infections at our complex hernia center.

Methods

We utilized our IRB approved, hernia quality database that captures detailed pre-, intra- and post-operative data on 100% of hernia cases performed by our four dedicated hernia surgeons. All patients with a known mesh infection were included in this study. Patients were excluded if there were no cultures obtained at the time of surgery. We extracted demographic variables and operative details from our hernia registry and then used chart review to evaluate cultures from the time of surgery.

Results

Our database contains 662 unique patients who have undergone ventral hernia repair between August of 2021 and June of 2025. All 13 patients who came to our institution with a mesh infection and had cultures obtained at the time of surgery had Gram-Positive bacteria in their samples. Seven cultures (54%) resulted as Staphylococcus aureus, with a majority exhibiting methicillin resistance (MRSA) (31% of all samples). Seven cultures (54%) resulted as Enterococcus spp. with one culture demonstrating both Staphylococcus aureus and Enterococcus spp.. Seven patients had polymicrobial infections with Gram-negative and Gram-positive organisms. The most common Gram-negative organisms were Klebsiella spp. (4, 31%) and E. coli (4, 31%), with Proteus spp. (3, 23%) and Pseudomonas spp. (2, 15%).

Conclusion

There is very little published data regarding the rate of chronic mesh infection after ventral hernia repair or the bacteria responsible for these infections.  It is critical to understand the bacteria responsible if we hope to eliminate this adverse outcome. Our results demonstrate the diversity of bacteria involved in chronic mesh infections and therefore the diversity of sources of infection and highlight the need for further study in this area.

Microbiota Transplantation Therapy Opposes Oral-Gut Translocation in Colorectal Surgery Patients

Authors:
Julia Frebault, Max Hill, Alexander Troester, Christopher Staley, Cyrus Jahansouz

Body of Abstract:
Background

In colorectal surgery, following surgical bowel preparation and colon resection, there are alterations of key genera in the gut microbiome. A rise in pathogenic genera in the postoperative period, particularly Streptococcus, has been linked to postoperative complications including anastomotic leak and surgical site infection. We hypothesized that the source of Streptococcus is the oral microbiome, and that fecal microbiota transplantation therapy (MTT) can repopulate beneficial genera and oppose the translocation of Streptococcus in the postoperative period.

 

Methods

This analysis was conducted in two phases: first, an exploratory cohort of 12 patients in whom fecal and saliva samples were analyzed surrounding resectional colon surgery (n=5) or colonoscopy (controls, n=7). Second, an interventional cohort of 12 patients who underwent colon resection for cancer or diverticular disease received microbiota transplant therapy (MTT) via orally-ingested formulation (IND 30860) and provided fecal samples for analysis. Samples were analyzed at up to six timepoints: pre-operative, within 24 hours of surgery (DOS), postoperative day (POD)10-14, POD30, POD90, and POD180. Microbial composition was assessed with 16S rRNA sequencing. Alpha and beta diversity was analyzed using mothur software. SourceTracker assessed the similarity of postoperative composition to donors as well as to patients’ own preoperative microbiota. Groups were compared using ANOVA, Kruskal-Wallis, and Spearman methods.

 

Results 

In the exploratory cohort, microbial diversity, assessed by Shannon index, differed significantly between surgical and control patients on the day of procedure through POD10 in saliva samples (P = 0.003 and 0.05, respectively), and at POD10 in fecal samples (P = 0.022). Streptococcus was present in higher abundance in the saliva and stool of surgical patients compared to controls. Surgical fecal samples maintained increased similarity to saliva samples compared to controls on DOS, persisting through POD10 (P = 0.29 and 0.04, respectively, Figure 1AB). In the interventional cohort, immediately following surgery, samples had 8.8% similarity to donor, which rose to 81.1% by POD90 (Figure 1C). Following MTT, engraftment was significantly negatively correlated with Streptococcus abundance (-0.61; P<0.01). As Streptococcus abundance declined, a rise in  commensal genera including Blautia and Faecalibacterium was noted (Figure 1D).   Conclusions In this two-part exploration of shifts in microbiota following colorectal surgery, oral translocation of Streptococcus was effectively prevented by oral administration of MTT. Further evaluation of the immunologic reaction to these changes and correlation with clinical outcomes will be beneficial in the development of MTT as a therapeutic intervention surrounding colorectal surgery.

Non-aeruginosa Pseudomonas spp: a critical analysis of 29 surgical and blood stream infections

Authors:
Hugo Bonatti, Saron Araya, Pooja Ajith, Sridha Gona, Aaron George

Body of Abstract:
Background: Pseudomonas aeruginosa is by far the most common non-fermentative Gram-negative rod causing human diseases. Due to new microbiology techniques recently re-classifications in this group of organisms were undertaken, and an increasing number of infections caused by other Pseudomonas strains have been reported, many in immuno-compromised individuals.

Methods: Our institutional database was searched for all surgical and blood stream infections caused by non-aeruginosa Pseudomonas spp. during a 4-year period. 

Results: In total 35 isolates of non-aeruginosa Pseudomonas spp. in 29 patients were identified. Median age of the cohort was 65.3 (range 0.1-88.2) years with 58.6% being male. Rates of comorbid conditions were DM 34%, hypertension 31%, hyperlipidemia 17%, COPD 7%, CAD 7%, and malignancies 10%; 61% of individuals were obese and 24% were active smokers. Demographic, clinical, and microbiology data are shown in table 1. Isolated strains included Ps. species       (14%), Ps. fluorescence (10%), Ps. putida (31%), Ps. fluorescence/putida (24%), Ps. luteola (10%), Ps. stutzeri (7%) and Ps. oleovorans (3%); 55% of infections were polymicrobial with staphylococci in 37%, streptococci in 13%, Gram-negative rods in 20%, anaerobes in 27% and yeast in 3% as co-pathogens. Blood cultures accounted for 28% of specimens, drainage fluids/tissue specimens for 31% and wound cultures for 38% of specimens, 3% came from drained abscesses. The specimens were sent in 31% by surgical services, 28% by medical services including critical care and infectious diseases, 21% by primary care physicians and 21% by the emergency department. Lower extremity soft tissue infections accounted for 62% of infections, upper extremities were involved in 3%, and 7% were intraabdominal infections. Treatment for surgical infections included incision and drainage, debridement and amputation as indicated together with antibiotics according to sensitivity testing, which showed great variability between strains. 

Conclusion: Non-aeruginosa Pseudomonas spp. are a diverse group of pathogens.  During the same time period 850 isolates of Ps aeruginosa in 572 patients were identified. Whereas most non-aeruginosa Pseudomonas infectious episodes were successfully treated, during a 2 year follow up 24% of patients died reflecting their severe chronic co-morbid conditions.

One of These Things Is Not Like the Others: Consideration of Healthcare-Associated Infection Risk in Burn Patients and Other Critically Ill Populations

Authors:
Megan Yoerg, Laura Johnson, Lauren Nosanov

Body of Abstract:
Introduction: Healthcare-associated infections (HAI) are a significant source of preventable morbidity, with the Centers for Disease Control and Prevention (CDC) estimating a prevalence of 3.2% in patients receiving inpatient care. Reporting and benchmarking common HAI is crucial to efforts in prevention and quality improvement. Risk for HAI is elevated in critically ill populations, but the variance based on specific illness and injury patterns is underappreciated. The pathophysiology of severe burn injury induces profound immunocompromise; coupled with loss of the barrier function provided by intact integumentary, this results in uniquely elevated infection risk. Prolonged hospitalization, persistent open wound burden, device days, and frequent surgical interventions additionally contribute. Broadly accepted HAI surveillance definitions may therefore be insufficient and under-stratified when applied to burn patients, with subsequent implications on reimbursement and quality benchmarking.

 

Methods: An in-depth review was conducted of the 2024 CDC National Healthcare and Safety Network (NHSN) Patient Safety Component Manual (PSCM). NHSN is the largest and most widely used tracking system for HAI in the United States, accounting for approximately 25,000 medical facilities, with the Patient Safety Component Manual serving as the prevailing document outlining surveillance definitions and standardization. Populations used to define HAI surveillance and case definitions were identified, with specific attention paid to representation of the burn patient population. Central Line-associate Bloodstream Infections (CLABSI) and Catheter-associated Urinary Tract Infections (CAUTI) were specifically reviewed due to their common and pervasive risk profiles across critically ill patients.  

 

Results: The PSCM explicitly mentions burn units throughout, they are generally grouped based on number of device days and length of stay. Referent groups included units specializing in labor and delivery, neurology, telemetry, and medical surgical, with care provided to patients with vastly different pathophysiology, critical illness, and immunocompromise.

 

Conclusions: Improved understanding of HAI risk in disparate patient populations is crucial. Beyond optimization of patient outcomes, HAI risk identification and mitigation has implication on resource utilization, insurance reimbursement, and reporting of hospital outcomes data. The value of benchmarking can only aid quality improvement efforts when patient populations are considered in comparison to others sharing equivalent risk profiles. As currently structured, the NHSN PSCM may be unfairly penalizing facilities providing the required specialized care to save and rehabilitate critically ill burn patients. Evidence-based re-evaluation of the PSCM referent groups is needed, however efforts will likely be hindered by the paucity of burn-specific HAI literature currently available.