Successful Use of Amoxicillin-clavulanate Acid in a Patient with Severe Wound Infection with Wound Communication Secondary to Actinomyces

Actinomyces is a common genus of bacteria that is typically found in the oral cavity, gastrointestinal tract, and genitourinary tract, as well as on the skin.¹Gleimia europaea (formerly A europaeus) is a facultative anaerobic gram-positive rod that has been well associated with abscesses of the groin, axilla, and breast, as well as with PIs.^1,2 Infection with this species usually involves multiple abscesses communicating through sinus tracts. Treatment typically requires prolonged courses of penicillin or amoxicillin for up to 12 months.³ In the present case report, a PI with fistulous tract and tunneling infected with Actinomyces responded well to treatment with amoxicillin–clavulanate acid.

A 62-year-old male with history of COPD, hypertension, and obesity with a body mass index of 33 was admitted to the hospital for management of severe COPD exacerbation requiring mechanical ventilation. An unstageable sacral PI with black eschar developed during the patient’s 10-day hospital stay. The PI was initially managed with offloading, frequent posture change, and daily change of dry cushion.

The patient was evaluated in the plastic surgery clinic 10 days after hospital discharge. On examination, he had a malodorous sacral PI and a left ischial PI with eschar (Figure 1). Debridement under local anesthesia was performed, and stage IV PI was diagnosed. Tissue culture was sent for analysis. Empiric treatment with doxycycline 100 mg twice a day was started. At 1-week follow-up, examination revealed an expanding sacral PI with communication to the stage III left ischial PI and loose eschar on the left buttock that was debrided again during that visit. The patient was instructed to continue wound care with twice-daily wet-to-moist dressing changes using one-quarter strength Dakin solution and gauze covered with a border dressing.

The patient was evaluated in the Infectious Diseases office a few days later. Review of wound culture revealed Actinomyces species (Gleimia europaea). Thus, doxycycline was discontinued and amoxicillin–clavulanate acid 875/125 mg twice a day was started for coverage of Actinomyces and anaerobes, given the location and depth of the injury. At 2-week follow-up, dramatic improvement in tunneling with excellent wound progression was noted (Figure 2). By 2 months after initiation of antibiotic, the wound had healed completely (Figure 3). Amoxicillin–clavulanate acid was de-escalated to amoxicillin alone, and amoxicillin therapy was planned for a total of 3 months owing to Actinomyces involvement.

The anaerobic bacterium Actinomyces causes an indolent, slowly progressive infection characterized by contiguous spread, suppurative and granulomatous inflammation with formation of multiple abscesses, and draining sinuses.

Actinomyces species are non-virulent opportunistic pathogens. To cause disease, a break in the integrity of physical barriers such as skin or mucous membranes is required. The presence of devitalized tissue aids invasion into deeper body structures. Skin and soft tissue infections with Actinomyces generally occur through a contagious source from direct inoculation or, less commonly, by hematogenous spread.^1,2

In the patient in the present case report, an unstageable sacral PI developed during a 10-day hospital stay for management of severe COPD exacerbation. Despite 2 sessions of surgical debridement of the sacral PI, it continued to expand and form fistulous tracts. The finding of actinomycotic involvement (G europaea) explains the progressive course with invasion of tissue planes despite surgical management. After the organism was identified, amoxicillin–clavulanate acid 875/125 mg twice daily was started. Within 2 weeks, the tunneling started to close and the wound began to heal.

Treatment of skin and soft tissue infection with Actinomycetes involves longer courses of antibiotics of up to 6 to 12 months to allow for adequate penetration of the infected area. Shorter duration of antibiotics up to 3 months can be considered if adequate surgical drainage, wound care, and debridement are achieved.⁴ In the patient in the present case report, significant improvement in the injury was noted 2 weeks after penicillin-based therapy was begun, which emphasizes the excellent susceptibility of Actinomyces to penicillin and highlights the advantage of combining aggressive surgical debridement, meticulous wound care, and appropriate antibiotic coverage to accelerate the healing process of sacral PIs affected by actinomycosis.

The main limitation of this study is that it is the case report of a single patient. Larger comparative studies are needed to investigate the pathogenesis of Actinomyces-infected PIs and the optimal antibiotic treatment strategy.

This case report discusses early diagnosis of actinomycosis involving sacral and left ischial PIs by identification of clinical characteristics, including sinus tract formation and tunneling. In this patient, the combination of initiation of appropriate antibiotics, surgical debridement, and wound care resulted in accelerated wound healing and an improved outcome.