Systemic and localized infections in humans caused by Paenibacillus: a case report and literature review.

Background: As opportunistic pathogens, Paenibacillus organisms rarely induce human infections. This research paper details the clinical manifestations, treatment, and prognosis of an intraocular infection caused by Paenibacillus in a 43-year-old male patient.

Case presentation: In this case, the patient initially presented with persistent ocular redness and a sensation of foreign bodies following trauma surgery. Upon admission, we performed intraocular fluid metagenomic next generation sequencing (mNGS) testing and systemic blood sampling for infection-related assessments. The results revealed a localized ocular infection with Paenibacillus organisms. Consequently, the patient received daily levofloxacin injections (500 mg) and clindamycin (300 mg) for systemic anti-infective therapy, along with subconjunctival injections of gentamicin (2 WIU) and dexamethasone (5 mg) for topical application. The infection was effectively managed, and their ocular symptoms showed improvement during the treatment course.

Conclusions: We conducted a comprehensive review of previously reported cases involving Bacillus-like organisms causing human infections, exploring mechanisms, diagnostic approaches, and treatment strategies.