Lysinibacillus fusiformis Bacteremia in an Immunocompetent Pregnant Woman as a Diagnostic Challenge: A Rare Case Report

On admission, she was febrile, with a temperature of 39°C, but without any rash.Chest imaging revealed bilateral pulmonary infiltrates, and laboratory studies showed hemoglobin 9.2 gm/dL, total leukocyte count 18400/μL with neutrophils of 89%, platelets 1.4 lakhs, alanine aminotransferase (ALT) 55 IU/L, aspartate aminotransferase (AST) 65 IU/L, bilirubin 1.2 mg/dL, blood urea nitrogen 28 mg/dL, creatinine 0.9 mg/dL, N-terminal pro-B-type natriuretic peptide (BNP) 244 pg/mL, and procalcitonin (PCT) 4.8 were noted.Despite initial management with noninvasive ventilation (NIV) with positive end-expiratory pressure (PEEP) of 6 cm of H 2 O and IntroductIonLysinibacillus fusiformis is a rod-shaped, gram-positive bacterium that forms endospores and was recently reclassified from the species Bacillus fusiformis.Although considered an environmental organism, L. fusiformis has been implicated in rare human infections, including dermal and oral ulcers, acute gastroenteritis, and bacteremia.However, due to limited documentation and paucity of available literature, the clinical picture and therapeutic strategies for L. fusiformis infections are not well-established, accounting for the lack of awareness among the treating clinicians.In this case, we describe a rare instance of L. fusiformis bacteremia in a pregnant woman, which was diagnosed with advanced microbiological techniques like matrix-assisted laser desorption/ionization timeof-flight (MALDI-TOF) and managed successfully with targeted antimicrobial therapy. case descrIptIonA 29-year-old pregnant woman, without any underlying comorbidities, initially presented to the hospital with severe abdominal pain and vaginal bleeding, resulting in a spontaneous abortion.She was admitted for short-term observation.Ten days later, she sought medical attention for generalized body pain and weakness, which had persisted for 1 week.Additionally, she developed high-grade fever with chills and rigors for 5 days, nonproductive cough, and progressive shortness of breath for 2 days.