IDCRP Combat-Related Extremity Wound Infection Research

Exploring fluoroquinolone resistance mechanisms and the effects of carbonyl cyanide 3-chlorophenylhydrazone (CCCP) in Acinetobacter baumannii

Objectives

This study aims to investigate the prevalence and mechanisms of fluoroquinolone resistance in Acinetobacter baumannii strains isolated from hospitals in Hamadan, west of Iran. It investigates the role of specific resistance genes and mutations in contributing to this resistance. In addition, the effects of carbonyl cyanide 3-chlorophenylhydrazone (CCCP) on the susceptibility of A. baumannii to fluoroquinolones will be evaluated to identify potential strategies to combat this growing problem.

Methods

A total of 102 A. baumannii isolates were collected from various clinical specimens between February and August 2023. Antimicrobial susceptibility testing was performed using the Kirby-Bauer disk diffusion method according to CLSI guidelines, focusing on eight antibiotics, including ciprofloxacin and levofloxacin. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) evaluations were also performed for these fluoroquinolones. The presence of plasmid-dependent fluoroquinolone resistance (PMQR) genes and mutations in the gyrA and parC genes were assessed by PCR. The effect of CCCP on antibiotic susceptibility and expression of efflux pump encoding gene was evaluated by real-time PCR.

Results

The study revealed alarmingly high resistance rates among the 102 A. baumannii isolates, with 97% resistant to imipenem, 96% to gentamicin, 92% to ciprofloxacin, and 86% to levofloxacin. Of the isolates, 87 were classified as multidrug resistant (MDR). Several resistance genes were identified, including qnrS (77.45%), oqxA (73.52%), and qnrA (72.54%). Mutations in the gyrA and parC genes were detected in several isolates, contributing to the observed resistance. In addition, treatment with CCCP resulted in a significant reduction in MICs for both ciprofloxacin and levofloxacin, highlighting its potential role in mitigating resistance.

Conclusion

The findings underscore the urgent need for improved surveillance and treatment strategies due to the high prevalence of fluoroquinolone resistance. While CCCP demonstrated potential in restoring antibiotic susceptibility, further studies are needed to assess its clinical applicability and potential toxicity. Additionally, the study is limited by its focus on a single geographic region, and further investigations across broader populations are necessary to generalize these findings.

Early post-trauma wound microbiota and its association with pain outcomes and mental health in combat-related extremity injuries: a prospective analysis

Introduction

Given that many armed conflicts are currently ongoing worldwide, a thorough study of issues related to providing medical care for the wounded is essential.

Material and methods

We included 45 participants aged 20-60 years with limb injuries in our study. The participants were surveyed using a visual analog pain scale, the PHQ-9, and the PTSD-5. We formed three groups: the first group included patients with limb amputations, the second group consisted of patients with limb trauma, and the third group involved patients with limb burns.

Results

We found that the average pain level in Group 1 was higher, though statistical significance was not achieved (p > 0,05). According to the PHQ-9, all participants exhibited depressive symptoms of varying severity. In the trauma group, patients reported fewer PTSD symptoms. Among the amputees, a significant predominance of Gram-negative microorganisms was noted. The correlation between the slightly higher pain levels and the significant predominance of Gram-negative flora in amputee patients was negative (P > 0.05).

Conclusions

In the amputee group, there was a trend toward higher mean pain scores compared to the other groups (p > 0,05). The same presence and distribution of depressive and PTSD symptoms were observed across all groups. Correlation analysis between pain intensity and contamination with Gram-negative bacteria did not reveal a relationship between these two variables. The study requires a larger patient sample. Gram-negative pathogens such as Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella oxytoca, and Proteus mirabilis were found more frequently among all patients.

In vitro antibiofilm efficacy of ertapenem, tobramycin, and moxifloxacin against biofilms grown in a glass bead or CDC Biofilm Reactor®

Laboratory grown biofilms are used to simulate bacterial growth in diverse environmental conditions and screen the effectiveness of anti-biofilm therapies. Recently, we developed a glass bead biofilm reactor that utilizes low broth volume to provide high-throughput biofilm growth for testing and translation across the research continuum (e.g., benchtop assays to preclinical models). Bioburden per mm2 surface area of Staphylococcus aureus and Pseudomonas aeruginosa biofilms were comparable on beads and CDC Biofilm Reactor® coupons. In this study, we hypothesized that biofilms grown on beads would be more susceptible to ertapenem, moxifloxacin, and tobramycin than those grown on coupons. Results indicated a significant reduction in S. aureus bioburden on glass beads compared to glass coupons following treatment with ertapenem (p = 0.005) and tobramycin (p = 0.014). P. aeruginosa biofilms had smaller differences in antibiotic response between the two systems. There was a significantly greater reduction in bead P. aeruginosa biofilm than coupon when treated with tobramycin (p = 0.035). This work offered insight into how the bead biofilm reactor could be used as a tool for antibiotic screening and translation across the continuum of in vitro to in vivo systems that support development of antimicrobial technology.

A controlled release antibiotic wound protectant gel formulated for use in austere environments

Battlefield wounds are at high risk of infection due to gross contamination and delays in evacuation from forward-deployed locations. The aim of this study was to formulate an antibiotic wound gel for application by a field medic in austere environments to protect traumatic wounds from infection during transport. Formulation development was conducted over multiple phases to meet temperature, handling, in vitro elution, and in vivo tissue response requirements. Thermal properties were evaluated by vial inversion, DSC, and syringe expression force in a temperature range of 4-49°C. Handling was evaluated by spreading onto blood-contaminated tissue and irrigation resistance. Controlled antibiotic release was evaluated by a modified USP immersion cell dissolution method. Local tissue effects were evaluated in vivo by subcutaneous implantation in rats for 7 and 28 days. An oleogel composition of cholesterol, hydrogenated castor oil, soybean oil, and glyceryl monocaprylocaprate met the target performance criteria. Peak expression force from a 5 mL syringe at 4°C was 48.3 N, the dropping point temperature was 68°C, and the oleogel formulation could be spread onto blood-contaminated tissue and resisted aqueous irrigation. The formulation demonstrated sustained release of tobramycin in PBS at 32°C for 5 days. Implantation in a rat dorsal pocket demonstrated a slight tissue reaction after 7 days with minimal to no reaction after 28 days, comparable to a commercial hemostat control. Material resorption was evident after 28 days. The formulation met target characteristics and is appropriate for further evaluation in a large animal contaminated blast wound model.

Point of Use Treatment for Medical Devices: From Bedside to Battlefield

INTRODUCTION

Point of use (POU) treatment is a critical first step of medical device reprocessing. Reusable instruments and flexible endoscopes require a minimum of terminal sterilization or high-level disinfection, neither of which can be guaranteed if POU is performed incorrectly. Compliance considerations for POU include hospital accreditation readiness, unique austere surgical mission requirements, and the transition of future conflict towards Large Scale Combat Operations. This integrative review aims to describe POU for reusable instruments and endoscopes, and extrapolate implications for Military Health System policies and future considerations.

MATERIALS AND METHODS

The authors performed an integrative review and comprehensive literature search in PubMed and CINAHL with the keywords "point of use," "point of use cleaning," "POU," "instrument," "high-level disinfection," "endoscope," and "clean." Articles were limited to "English" and "human" from 2017 to 2023. The authors also performed a thorough review of the Defense Health Agency and service-specific doctrine, as well as national guidelines regarding POU adherence.

RESULTS

The literature review yielded 18 articles that discussed the transport and reprocessing of reusable medical devices. Regulatory standards and national guidelines were used to supplement the literature. Seventeen evidence-based criteria were extrapolated from the literature to generate two step-by-step guides for the POU treatment of endoscopes and reusable instruments (Tables I and II). Despite increased morbidity and mortality rates linked to inadequate device reprocessing, compliance with POU procedures remains low. Barriers to practice included complex POU processes, intricately designed surgical instruments and endoscopes, lack of healthcare worker (HCW) knowledge and competency, and inadequate or ambiguously written policies. Training, competency assessments, and clearly written policies and procedures can be cost-effective, evidence-based, and feasible solutions.

CONCLUSION

Completing POU treatment is critical to a successful surgical mission in both the hospital and austere environment. Implications to practice include implementing evidence-based POU programs that improve patient outcomes and readiness while decreasing costs.

Long-term results of treatment of Gustilo-Anderson type 3A-B tibia fractures due to combat-related high-energy ballistic injuries treated with external circular fixator: Experience of the Military Medical Academy

OBJECTIVES

The aim of this study was to evaluate the longterm outcomes of open tibia fractures treated using the Ilizarov external circular fixation (ECF) technique in the Military Medical Academy.

PATIENTS AND METHODS

Between January 1992 and December 2011, a total of 134 male military personnel (median age: 22.5 years; range, 18 to 36 years) with Gustilo-Anderson type 3 open tibia fractures treated with ECF were retrospectively analyzed. All patients underwent multiple surgeries and eventually Ilizarov fixation surgery. The radiological and functional outcomes were evaluated using the Association for the Study and Application of Methods of Ilizarov (ASAMI) criteria, and complications were noted.

RESULTS

The median follow-up was 17.7 (range, 10 to 29) years. The median time to union was 4.7 (range, 3 to 8) months. All frames were removed from the limb, when union was observed. No re-fracture, limb length discrepancy more than 2.5 cm, or below-knee amputation after Ilizarov treatment was seen in any patient. Chronic osteomyelitis was observed at in 40% (n=54) of the patients at a median time ranging from 17 to 148 months. The overall ASAMI bone scores were excellent in 40 (30%), good in 20 (15%), fair in 20 (15%), and poor in 54 (40%) patients with osteomyelitis. The ASAMI functional scores were excellent in 40 (30%), good in 40 (30%), and fair in 54 patients (40%). No poor score was observed. Minor pin site infections were observed in 63 patients (47%).

CONCLUSION

Our long-term study results showed that all patients returned to their social life and were mobilized without support after treatment with the use of Ilizarov ECF method of open tibia fractures caused by high-energy ballistic injuries. However, complications such as pin tract infections and osteomyelitis after several years must be kept in mind in the treatment of comminuted bone fractures caused by firearms and ballistic missiles injuries.

Department of Defense Trauma Registry Infectious Disease Module Impact on Clinical Practice

BACKGROUND

The Joint Trauma System (JTS) is a DoD Center of Excellence for Military Health System trauma care delivery and the DoD's reference body for trauma care in accordance with National Defense Authorization Act for Fiscal Year 2017. Through the JTS, evidence-based clinical practice guidelines (CPGs) have been developed and subsequently refined to standardize and improve combat casualty care. Data are amassed through a single, centralized DoD Trauma Registry to support process improvement measures with specialty modules established as the registry evolved. Herein, we review the implementation of the JTS DoD Trauma Registry specialty Infectious Disease Module and the development of infection-related CPGs and summarize published findings on the subsequent impact of the Infectious Disease Module on combat casualty care clinical practice and guidelines.

METHODS

The DoD Trauma Registry Infectious Disease Module was developed in collaboration with the Infectious Disease Clinical Research Program (IDCRP) Trauma Infectious Disease Outcomes Study (TIDOS). Infection-related information (e.g., syndromes, antibiotic management, and microbiology) were collected from military personnel wounded during deployment June 1, 2009 through December 31, 2014 and medevac'd to Landstuhl Regional Medical Center in Germany before transitioning to participating military hospitals in the USA.

RESULTS

To support process improvements and reduce variation in practice patterns, data collected through the Infectious Disease Module have been utilized in TIDOS analyses focused on assessing compliance with post-trauma antibiotic prophylaxis recommendations detailed in JTS CPGs. Analyses examined compliance over three time periods: 6 months, one-year, and 5 years. The five-year analysis demonstrated significantly improved adherence to recommendations following the dissemination of the 2011 JTS CPG, particularly with open fractures (34% compliance compared to 73% in 2013-2014). Due to conflicting recommendations regarding use of expanded Gram-negative coverage with open fractures, infectious outcomes among patients with open fractures who received cefazolin or expanded Gram-negative coverage (cefazolin plus fluoroquinolones and/or aminoglycosides) were also examined in a TIDOS analysis. The lack of a difference in the proportion of osteomyelitis (8% in both groups) and the significantly greater recovery of Gram-negative organisms resistant to aminoglycosides or fluoroquinolones among patients who received expanded Gram-negative coverage supported JTS recommendations regarding the use of cefazolin with open fractures. Following recognition of the outbreak of invasive fungal wound infections (IFIs) among blast casualties injured in Afghanistan, the ID Module was refined to capture data (e.g., fungal culture and histopathology findings, wound necrosis, and antifungal management) needed for the TIDOS team to lead the DoD outbreak investigation. These data captured through the Infectious Disease Module provided support for the development of a JTS CPG for the prevention and management of IFIs, which was later refined based on subsequent TIDOS IFI analyses.

CONCLUSIONS

To improve combat casualty care outcomes and mitigate high-consequence infections in future conflicts, particularly in the event of prolonged field care, expansion, refinement, and a mechanism for sustainability of the DoD Trauma Registry Infectious Disease Module is needed to include real-time surveillance of infectious disease trends and outcomes.

DoD-VA Trauma Infection Research Collaboration

BACKGROUND

In the aftermath of wars, there is a surge in the number of wounded service members who leave active duty and become eligible for healthcare through the Department of Veterans Affairs (VA). Collaborations between the Department of Defense (DoD) and VA are crucial to capture comprehensive data and further understand the long-term impact of battlefield trauma. We provide a summary of the development, methodology, and status of an effective collaboration between the Infectious Disease Clinical Research Program and the St. Louis VA Health Care System with the multicenter, observational Trauma Infectious Disease Outcomes Study (TIDOS), which examines the short- and long-term outcomes of deployment-related trauma.

METHODS

As part of TIDOS, wounded service members who transitioned to participating military hospitals in the United States (2009-2014) were given the opportunity to enroll in a prospective follow-up cohort study to continue to capture infection-related data after their hospital discharge. Enrollees in the TIDOS cohort who left military service and received health care through the VA also had the option of consenting to have relevant VA medical records abstracted and included with the study data. Infections considered to be complications resulting from the initial trauma were examined.

RESULTS

Among 1,336 TIDOS enrollees, 1,221 (91%) registered and received health care through the VA with 633 (47%) consenting to follow-up using VA records and comprising the TIDOS-VA cohort. Of the first 337 TIDOS-VA cohort enrollees, 38% were diagnosed with a new trauma-related infection following hospital discharge (median: 88 days; interquartile range: 18-351 days). Approximately 71% of the infections were identified through DoD sources (medical records and follow-up) and 29% were identified through VA electronic medical records, demonstrating the utility of DoD-VA collaborations. The TIDOS DoD-VA collaboration has also been utilized to assess intermediate and long-term consequences of specific injury patterns. Among 89 TIDOS-VA cohort enrollees with genitourinary trauma, 36% reported sexual dysfunction, 21% developed at least one urinary tract infection, 14% had urinary retention/incontinence, and 8% had urethral stricture. The rate of urinary tract infections was 0.05/patient-year during DoD follow-up time and 0.07/patient-year during VA follow-up time.

CONCLUSIONS

Wider capture of infection-related outcome data through the DoD-VA collaboration provided a clearer picture of the long-term infection burden resulting from deployment-related trauma. Planned analyses include assessment of osteomyelitis among combat casualties with amputations and/or open fractures, evaluation of mental health and social factors related to injury patterns, and examination of health care utilization and cost in relation to infectious disease burdens.

Multidrug-Resistant and Virulent Organisms Trauma Infections: Trauma Infectious Disease Outcomes Study Initiative

INTRODUCTION

During the wars in Iraq and Afghanistan, increased incidence of multidrug-resistant (MDR) organisms, as well as polymicrobial wounds and infections, complicated the management of combat trauma-related infections. Multidrug resistance and wound microbiology are a research focus of the Trauma Infectious Disease Outcomes Study (TIDOS), an Infectious Disease Clinical Research Program, Uniformed Services University, research protocol. To conduct comprehensive microbiological research with the goal of improving the understanding of the complicated etiology of wound infections, the TIDOS MDR and Virulent Organisms Trauma Infections Initiative (MDR/VO Initiative) was established as a collaborative effort with the Brooke Army Medical Center, Naval Medical Research Center, U.S. Army Institute of Surgical Research, and Walter Reed Army Institute of Research. We provide a review of the TIDOS MDR/VO Initiative and summarize published findings.

METHODS

Antagonism and biofilm formation of commonly isolated wound bacteria (e.g., ESKAPE pathogens-Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.), antimicrobial susceptibility patterns, and clinical outcomes are being examined. Isolates collected from admission surveillance swabs, as part of infection control policy, and clinical infection workups were retained in the TIDOS Microbiological Repository and associated clinical data in the TIDOS database.

RESULTS

Over the TIDOS study period (June 2009 to December 2014), more than 8,300 colonizing and infecting isolates were collected from military personnel injured with nearly one-third of isolates classified as MDR. At admission to participating U.S. military hospitals, 12% of wounded warriors were colonized with MDR Gram-negative bacilli. Furthermore, 27% of 913 combat casualties with ≥1 infection during their trauma hospitalization had MDR Gram-negative bacterial infections. Among 335 confirmed combat-related extremity wound infections (2009-2012), 61% were polymicrobial and comprised various combinations of Gram-negative and Gram-positive bacteria, yeast, fungi, and anaerobes. Escherichia coli was the most common Gram-negative bacilli isolated from clinical workups, as well as the most common colonizing MDR secondary to extended-spectrum β-lactamase resistance. Assessment of 479 E. coli isolates collected from wounded warriors found 188 pulsed-field types (PFTs) from colonizing isolates and 54 PFTs from infecting isolates without significant overlap across combat theaters, military hospitals, and study years. A minority of patients with colonizing E. coli isolates developed subsequent infections with the same E. coli strain. Enterococcus spp. were most commonly isolated from polymicrobial wound infections (53% of 204 polymicrobial cultures). Patients with Enterococcus infections were severely injured with a high proportion of lower extremity amputations and genitourinary injuries. Approximately 65% of polymicrobial Enterococcus infections had other ESKAPE organisms isolated. As biofilms have been suggested as a cause of delayed wound healing, wound infections with persistent recovery of bacteria (isolates of same organism collected ≥14 days apart) and nonrecurrent bacterial isolates were assessed. Biofilm production was significantly associated with recurrent bacteria isolation (97% vs. 59% with nonrecurrent isolates; P < 0.001); however, further analysis is needed to confirm biofilm formation as a predictor of persistent wound infections.

CONCLUSIONS

The TIDOS MDR/VO Initiative provides comprehensive and detailed data of major microbial threats associated with combat-related wound infections to further the understanding of wound etiology and potentially identify infectious disease countermeasures, which may lead to improvements in combat casualty care.