Abstract
Emphysematous pyelonephritis (EPN) is a rare necrotizing infection of the renal parenchyma and pelvicalyceal system caused by gas-forming organisms. We describe a novel case of an elderly woman with poorly controlled diabetes mellitus and end-stage renal failure on peritoneal dialysis, who developed polymicrobial EPN involving the Bifidobacterium breve and Klebsiella pneumoniae pathogens. She was successfully treated with culture-directed parenteral antibiotics and percutaneous drainage of renal collections. To our knowledge, B. breve is a previously unreported cause of EPN. This report highlights its potential in causing opportunistic infections in immunocompromised hosts in the appropriate clinical context.