Successful dual therapy of aztreonam and ceftazidime–avibactam for multidrug-resistant Stenotrophomonas maltophilia infection in a preterm neonate: A life-saving approach

Stenotrophomonas maltophilia is a multidrug-resistant gram-negative pathogen associated with high morbidity and mortality, especially in immunocompromised patients. Its resistance mechanisms include aminoglycoside-modifying enzymes, qnrB -like quinolone resistance genes, multidrug efflux pumps, and β-lactamases (L1 and L2). With the increasing incidence of S. maltophilia infections, effective treatment strategies are urgently needed to combat its growing resistance. We present the case of a preterm male neonate, born at 30 weeks of gestation, who developed respiratory distress requiring mechanical ventilation. Empiric antibiotics were initiated but failed to prevent clinical deterioration. Respiratory cultures confirmed that multidrug-resistant S. maltophilia is resistant to standard therapies, necessitating a novel dual regimen of ceftazidime–avibactam and aztreonam. This combination therapy was administered for 14 days, leading to microbiological clearance and clinical improvement, allowing successful extubation. To the best of our knowledge, this is the first documented case of ceftazidime–avibactam and aztreonam successfully treating multidrug-resistant S. maltophilia infection in a preterm infant. This case underscores the potential of ceftazidime–avibactam and aztreonam as a viable therapeutic option for multidrug-resistant S. maltophilia infections in neonates. Further studies are warranted to validate its safety and efficacy in similar cases.