RESUMEN
A member of the Enterobacteriaceae family, Providencia alcalifaciens is typically recognized as a source of gastrointestinal illness. Although its pathogenicity is not well known, many studies have suggested its mechanism of action involves the invasion of the intestinal mucosal layer. Although P. alcalifaciens is a urease producing microorganism, it has not been associated with the formation of a staghorn calculus in the setting of a urinary tract infection. This organism is neither commonly pursued in research or investigation nor is it commonly tested for in the clinical setting. This is especially true when combined with other disease processes, such as calculus formation. The advancement of antibiotic resistance, such as carbapenemase-producing strains, should bring more attention and routine investigation to this organism in the acute stage of infection. In this case report we introduce a 43-year-old Cuban female, who presents with a left-sided staghorn calculi and urine culture positive for carbapenemase-producing P. alcalifaciens.