ATLANTA — To help improve the care of troops injured in combat, the United States military has been exploring the complex microbiology of combat wounds.
The Multidrug-Resistant and other Virulent Organisms Trauma Infections Initiative, a collaborative effort among several Department of Defense laboratories, has collected broad data on infectious threats associated with injuries sustained in battle, according to findings presented at ASM Microbe.
The goal of the initiative “is to expand the understanding of the complex microbiology inherent within combat-related extremity wounds,” according to Katrin Mende, PhD, of the infectious disease clinical residency program in the Department of Preventive Medicine and Biostatistics at the Uniformed Services University of the Health Sciences, and colleagues.
Mende and colleagues evaluated clinical data and pathogens including Enterococcus, Pseudomonas aeruginosa and molds from patients who were part of the Trauma Infectious Disease Outcomes study, which was conducted from 2009 to 2014.
A total of 374 initial P. aeruginosa wound and blood isolates were included for 146 patients — 90% of them with blast-related injuries — with 40 patients having serial isolates occurring at least 7 days apart from any site, the researchers reported. The patients had a median hospital say of 57 days and a median injury severity score (ISS) of 33 — more than double the threshold defining major trauma. Fourteen patients with multidrug-resistant isolates had higher median ISS scores (50 vs. 33, P <.01), longer hospital stays (140 vs. 55 days, P < 0.01) and longer media duration of mechanical ventilation (10 vs. 6 days).
Assessing the antifungal resistance of mold isolates in 18 patients, the researchers reported various levels of susceptibility or resistance among Aspergillus flavus, A. fumigatus, Fusarium spp. and mucoromycetes. They said no new resistance was identified in most serial isolates once antifungal therapy was initiated.
Biofilm formation in 376 Enterococcus wound isolates was found to be generally weak — 8.8% in the presence of human plasma and 1.9% in the absence of human plasma, Mende and colleagues reported. They said E. faecalis showed the greatest biofilm formation response: 30% in the presence of human plasma.
“A better understanding of the complex microbiology of extremity wounds and infections can lead to improvements in combat casualty care, and the development and implementation of antimicrobial countermeasures,” the researchers wrote. – by Marley Ghizzone
Mende K, et al. Abstract AAR LB8. Presented at: ASM Microbe; June 7-11, 2018; Atlanta.
The researchers report no relevant financial disclosures.