A Longitudinal Evaluation of the Bacterial Pathogens Colonizing Chronic Non-Healing Wound Sites at a United States Military Treatment Facility in the Pacific Region.

PURPOSE: The biology of chronic wounds is complex and many factors act concurrently to impede healing progress. In this study, the dynamics of microflora changes and their antibiotic susceptibility patterns were evaluated longitudinally over 30 days using data from 28 patients with a total of 47 chronic lower extremity wounds. MATERIALS AND METHODS: In this study, colonized wound isolates were characterized using cultural, biochemical, and VITEK 2 methods. Antibiotic susceptibility patterns of the wound isolates were analyzed using various phenotypic assays. Furthermore, antimicrobial resistance patterns and the presence of mutations were evaluated by a genotypic assay, whole-genome sequencing (WGS). RESULTS: Staphylococcus aureus and Pseudomonas aeruginosa were found to be the most common strains at early time points, while members of Enterobacteriaceae were prevalent at later stages of infection. Antimicrobial resistance testing and whole-genome sequencing revealed that the molecular and phenotypic characteristics of the identified wound pathogens remained relatively stable throughout the study period. It was also noted that Enterobacter and Klebsiella species may serve as reservoirs for quinolone resistance in the Pacific region. CONCLUSION: Our observations showed that wounds were colonized with diverse bacteria and interestingly their numbers and/or types were changed over the course of infection. The rapid genetic changes that accompanied the first 4 weeks after presentation did not directly contribute to the development of antibiotic resistance. In addition, standard wound care procedures did not appear to select for resistant bacterial strains. Future efforts should focus on defining those genetic changes associated with the wound colonizing microorganisms that occur beyond 4 weeks.

An Unusual Wound Infection Due to Acinetobacter junii on the Island of Oahu: A Case Report.

The genus Acinetobacter has long been associated with war wounds. Indeed, A baumannii was responsible for so many infected wounds during Operation Iraqi Freedom that it was given the nickname "Iraqibacter." Therefore, it is important to monitor the occurrence and spread of Acinetobacter species in military populations and to identify new or unusual sources of infection. A junii is an infrequently reported human pathogen. Here, we report a case of a slow-healing wound infection with A junii in a woman on the island of Oahu. This case highlights the pathogenic potential of this organism and the need for proper wound care when dealing with slow-healing wounds of unknown etiology. It also underscores the need for identifying species of Acinetobacter that are not A baumannii to better understand the epidemiology of slow-healing wound infections.

Recovery of Bacteria and Fungi From a Leg Wound.

Acute and chronic wound infections can both be encountered in the deployed setting. These wounds are often contaminated by bacteria and fungi derived from the external environment. In this article, we present the case of a wound infection simultaneously colonized by Enterobacter cloacae (a bacterial pathogen) and Trichosporon asahii (an unusual fungal pathogen). We describe the examination and treatment of the patient and review the distinguishing characteristics of each organism.

A Case of Wound Infection with Providencia rettgeri and Coincident Gout in a Patient from Guam.

Providencia rettgeri (P. rettgeri) is a ubiquitous organism that is infrequently associated with human disease. Here we report the isolation of this organism from a polymicrobial wound infection resulting from ruptured tophi on a 54-year-old male patient from Guam. We describe the identification and confirmation of this organism, and propose metabolic synergy as a possible mechanism of pathogenesis. To our knowledge, this is the first published report of a wound infection colonized by P. rettgeri from Guam, and the first report to speculate upon the role of bacterial synergy in P. rettgeri pathogenesis.