First Report of Multidrug-Resistant Staphylococcus sciuri Isolated from the Urinary Bladder of a Domestic Rabbit in Romania: A Case Study.

Background/Objectives: Staphylococcus sciuri, traditionally regarded as a commensal organism in animals and the environment, is increasingly recognized as a potential opportunistic pathogen with zoonotic significance. Its genomic reservoir of methicillin resistance homologues further raises concern regarding its role in antimicrobial resistance dissemination. This study describes the first documented case of S. sciuri isolated from the urinary bladder of a domestic rabbit (Oryctolagus cuniculus) in Romania, emphasizing its clinical relevance and antimicrobial profile. Methods: A seven-year-old intact female rabbit presenting with apathy, dysuria, and hematuria underwent clinical evaluation, ultrasonography, and cystocentesis. The aspirated intravesical content was subjected to bacterial culture, MALDI-TOF MS identification, and antimicrobial susceptibility testing via the VITEK 2 system. Results: Pure colonies of Gram-positive cocci were identified as S. sciuri with high confidence. Antimicrobial susceptibility testing revealed susceptibility to β-lactams, aminoglycosides, glycopeptides, linezolid, rifampicin, fusidic acid, tigecycline, and trimethoprim-sulfamethoxazole, while resistance was observed against fluoroquinolones, macrolides, lincosamides, and tetracycline, indicating a multidrug-resistant phenotype. Treatment with trimethoprim-sulfamethoxazole combined with ultrasound-guided bladder lavage and supportive therapy resulted in complete clinical recovery within 10 days. Conclusions: This case highlights the pathogenic potential of S. sciuri in domestic rabbits and its capacity to exhibit multidrug resistance. The findings underscore the necessity of including rabbits in antimicrobial resistance surveillance programs and reinforce the importance of culture and sensitivity testing in guiding the therapeutic management of exotic companion animals.