Myroides odoratus polymicrobial cellulitis complicated by sepsis and acute kidney injury in an adolescent with focal segmental glomerulosclerosis: a case report

Myroides odoratus is a rare, non-fermenting gram-negative bacillus with intrinsic broad-spectrum antimicrobial resistance mediated by chromosome-encoded metallo-β-lactamases, rendering most empirical regimens ineffective. Although more than 100 human infections have been documented, to our knowledge, we identified no previously reported case of Myroides cellulitis in the setting of nephrotic syndrome. A 17-year-old boy with newly diagnosed focal segmental glomerulosclerosis, receiving prednisolone, presented one month into therapy with bullous cellulitis of both lower limbs complicated by sepsis and rapidly progressive acute kidney injury (Kidney Disease: Improving Global Outcomes stage 3) requiring haemodialysis. Initial empirical therapy with amoxicillin-clavulanate and clindamycin failed, and escalation to piperacillin-tazobactam and linezolid was undertaken at 48 h. Pus culture results, available on Day 4, yielded a polymicrobial growth of Klebsiella pneumoniae and Myroides odoratus , the latter susceptible only to minocycline. Targeted therapy against both organisms, with intravenous minocycline and ceftazidime, was followed by defervescence by Day 10, with renal recovery and sterile repeat culture by Day 25. This case illustrates the vulnerability of adolescents with nephrotic syndrome receiving corticosteroids to severe polymicrobial soft-tissue infection, and the value of early pus culture and susceptibility-directed therapy when empirical regimens fail. Myroides odoratus was one of two co-isolated pathogens, together with Klebsiella pneumoniae , and both were treated concurrently; M. odoratus therefore cannot be regarded as the sole cause of the cellulitis, sepsis or acute kidney injury, and the relative contribution of each organism cannot be distinguished. Published literature indicates that minocycline is among the agents most consistently active against Myroides , and susceptibility testing should guide therapy.