The collection of clinical specimens from wounds for culture and the subsequent microbiological study of these isolates is important to identify the type of microorganisms present, screen for new microorganisms, and ascertain their susceptibility to antimicrobial agents, which can lead to choosing the correct therapeutic protocol.3,13 In the current study, the bacterium collected from the leg wound was not associated with infection. The only presenting clinical sign was pain. However, some authors have demonstrated K gyiorum infection from different clinical sites, such as in urinary, pulmonary, and integumentary systems.4–6 Previous case reports of K gyiorum showed that associated infection usually developed with a long-standing inflammatory condition; however, that was not the case in the current patient.4–6,14
Resistance to ciprofloxacin was first described for K gyiorum by Pence et al.12 That case study reported 2 K gyiorum: 1 isolated from otitis media that was fully resistant to ciprofloxacin (MIC = 32 µg/mL) and the other from a chronic wound (MIC = 4 µg/mL).12 However, in both cases reported by Pence et al,12 patients had been treated previously with ciprofloxacin. In 2014 in the United States, a case report described K gyiorum obtained from bronchoalveolar lavage that had intermediate susceptibility to ciprofloxacin (MIC = 2 µg/mL).5 In all cases described, MIC was determined by ETEST. Despite K. gyiorum not being present in a wound in the US study, that report points to ciprofloxacin resistance similar to what was found in the current study.
Likewise, resistance to ciprofloxacin has been largely described in Enterobacteriaceae due to frequent use of this antibiotic.15–17 The main mechanism in fluoroquinolone resistance is the accumulation of mutations in the target enzymes, namely DNA gyrase and DNA topoisomerase IV. However, the presence of genes encoding efflux pumps has provided low levels of resistance to this class of antibiotics in E coli isolates over the past decade.18,19 Therefore, as low levels of resistance to ciprofloxacin were detected in the isolated K gyiorum, the authors believe that genes encoding efflux pumps could be the major mechanism of ciprofloxacin resistance in the current case. It is important to emphasize that S. aureus collected together with K gyiorum only presented resistance to penicillin; thus, K gyiorum can be a reservoir of ciprofloxacin resistance genes.
A study in the United States related the first case of bacteremia and sepsis due to K gyiorum in a patient with chronic lower-extremity ulcers, which draws more attention to these microorganisms.8 It is difficult to establish if K. gyiorum was acting as a pathogen or if it was simply present in the wound, but based on the presenting clinical signs of the wound in this case and in other reports,8,14 the authors suggest that in this case, K gyiorum was just present in the wound, not causing an important inflammatory response or infectious process.
To the authors’ knowledge, there are few published scientific articles on K gyiorum, and the articles that were found are case studies. Hence, it is not possible to establish causal relationships among chronicity, infection, or inflammatory processes and K gyiorum. More research is needed to ascertain the clinical effects and potential treatment of wounds containing K gyiorum.