First case report of Shewanella indica isolated from a hospitalized patient in Serbia

Over the past decade, <i>Shewanella</i> spp. have been increasingly recognized as opportunistic pathogens, particularly in patients with malignancies, neutropenia, severe heart failure, renal insufficiency, and hepatobiliary diseases. <i>Shewanella indica</i> is a rarely reported species within the <i>Shewanella</i> genus, and its role in human infection remains poorly documented. In this study, we report the first case of <i>S. indica</i> isolated from the stool of a critically ill 72-year-old man in Serbia with multiple pre-existing comorbidities and co-infections. Initial identification using the VITEK 2 system misclassified the strain as <i>Shewanella algae</i>, while species-level identification by the matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) was inconclusive. However, whole-genome sequencing (WGS) definitively identified the isolate as <i>S. indica</i> and revealed a multidrug-resistant profile together with numerous virulence-associated genes. Minimum inhibitory concentrations (MICs) were determined for 32 antibiotics, although interpretation was constrained by the lack of species-specific breakpoints. This case highlights the diagnostic challenges in differentiating <i>Shewanella indica</i>, discusses its possible clinical roles, and underscores the value of genomic tools for accurate identification. It also reinforces the importance of recognizing rare pathogens in complex clinical scenarios.