Recurring Osteomyelitis Caused by Clostridium celerecrescens in an Adolescent After Motocross Trauma: The Importance of Multidisciplinary Care
2022-10-12

To the Editors: A 15-year-old male adolescent was presented to the emergency department of the trauma unit with a type II open fracture of the left lower arm caused by an accident during a cross-country motorcycle race (Fig. 1A,B). He had gotten off track and lost control of this motorcycle, thereby crashing on to dry meadow soil. The patient presented hemodynamically stable and was prepared for debridement and elastic stable intramedullary nailing. He was started on intravenous cefuroxime. White blood counts and C-reactive protein (CRP) were unremarkable, except for a brief postoperative increase in CRP. Microbiological cultures of the intraoperative swabs yielded Bacillus thuringiensis and Pseudomonas koreensis (both on an aerobic medium), upon which the treatment was changed to meropenem according to susceptibility results (Table S1, Supplemental Digital Content 1, https://links.lww.com/INF/E809). After 9 days, treatment was stopped, and the patient was discharged.FIGURE 1.: Radiographic and computed tomography findings of a left radius type II open fracture of a 15-year-old male adolescent; (A,B) before the first surgery; (C,D) after external fixation; (E) follow-up visit 15 months after discharge.After 5 weeks, he presented again with pain in the lower arm on rotation and with slight wound discharge. MR imaging of the left arm showed the presence of an inflammatory process of the radius with subperiostal abscess formation. The patient underwent surgical revision, including removal of the nailing, wound debridement and external fixation. Intravenous cefuroxime was re-initiated. Tissue and swab cultures revealed Clostridium celerecrescens and Clostridium sphenoides from an anaerobic medium, and Paenibacillus macerans from an aerobic medium. Clindamycin was added before susceptibility testing was finished. Upon final susceptibility results (Table S1, Supplemental Digital Content 1, https://links.lww.com/INF/E809), a multidisciplinary team consisting of trauma surgeons, pediatric infectious diseases specialists, and clinical microbiologists was formed to discuss the case. Based on the susceptibility testing results, the decision was made to start ampicillin-sulbactam and metronidazole. After 7 days, the patient underwent surgical revision and repeat sampling. Cultures again revealed C. celerecrescens. Three-dimensional reconstruction computed tomography of the left arm yielded a suspicious lesion compatible with bone sequestration (Fig. 1C,D), upon which the decision for another surgical revision was made, 7 days after the previous revision. Intraoperatively, two avital bone fragments of approximately 2.8 cm were removed. Follow-up cultures revealed no bacterial growth. Intravenous ampicillin-sulbactam and metronidazole were continued for a total of 5 weeks. On discharge, the patient was switched to oral sultamicillin and metronidazole for another 4 weeks. No side effects related to the antibacterial therapy were reported. After 2 months, the external fixator was removed after imaging confirmed sufficient fracture healing. On regular follow-up visits, the patient presented in a good general state without functional compromise, whereas radiologic findings showed a 17° axis deviation of the radius (Fig. 1E). Anaerobic osteomyelitis is a rare event in children and adolescents but can occur in the presence of predisposing factors such as decubital ulcers, vascular disease, peripheral neuropathy, bites or trauma.1 The most frequently described pathogens in pediatric anaerobic osteomyelitis are Peptostreptococcus spp., Prevotella spp., Fusobacterium spp., Bacteroides fragilis group and Clostridium spp.1 However, aerobic pathogens can be involved as well, for example, Staphylococcus aureus.2,3 Only a few cases of human infections caused by C. celerecrescens have been reported (Table S2, Supplemental Digital Content 1, https://links.lww.com/INF/E809).4–6 There are some features of our case that deserve discussion. First, cefuroxime was started initially and then changed to meropenem. The presence of microorganisms indicating contact with soil may have been suggestive of further pathogens, particularly spore-forming, ubiquitous bacteria. Therefore, meropenem may have been more appropriate than cefuroxime. However, the 9-day-course was longer than currently recommended for open fractures.7 Yet, apparently it did not suffice to prevent a relapse. Second, imaging turned out to be pivotal in showing the presence of bone sequestrations that prompted another revision and led to ultimately decisive source control, alongside the appropriate antibacterial therapy. Third, the detection of multiple bacteria should not be discarded per default as contamination in patients with open fractures and potential inoculation of soil microorganisms. Last, our case demonstrates the importance of a multidisciplinary approach in the care of patients with complicated post-traumatic bone and joint infections. In conclusion, relapses due to spore-forming bacteria such as Clostridium spp. can occur several weeks to months after the initial open fracture. Therefore, a high level of suspicion should be maintained in these patients even after a clinically inapparent follow-up interval. ACKNOWLEDGMENTS We thank the patient and his mother for their consenting to this report. Written informed consent was obtained from both the patient and the parent before any data was used for this case report. This case report has been presented at the 2021 annual meeting of the German Society for Pediatric Infectious Diseases.