Case Presentation:

54 y.o female with a pmh of DM and HTN presented with 3 days of fever, chills and left flank discomfort. The patient reported the pain to be indolent in onset, dull and persistent w/o radiation. Fever, chills and anorexia began 2 days after onset of pain.  All other review of systems were negative. She denied recent antibiotics, hospitalization or catheterization. Her vital signs were T101.3, HR140, BP147/83 RR16. Physical exam was notable for left CVA tenderness. Laboratory results were significant for WBC19,000 with 86%neutrophils, creatinine 1.3mg/dl (baseline Cr = 0.7), and lactic acid 2.1mmol/L. UA showed >10WBC/hpf, <5 RBC/hpf, moderate blood, trace leukocyte esterase, negative nitrite, bacteria present.

Concern for obstructive uropathy prompted a CT of abdomen and pelvis, which confirmed a 1.8cm obstructing stone at the left UPJ causing mild left hydroureteronephrosis and stranding of the perinephric fat. Urine and blood cultures were obtained and pt was given IV Gentamicin and Vancomycin and taken emergently to OR for stent placement and stone removal. She was admitted to ICU for severe sepsis. Urine and two sets of blood cultures were positive for Lactobacillus Jensenii. She improved and sensitivities allowed deescalation to Augmentin.

Discussion: Lactobacillus jensenii, a gram positive rod-shaped bacterium, is a common inhabitant of both the GI and female GU tracts. While L. jensenii is part of the normal flora, it has been implicated in severe infections including bacteremia, endocarditis and vascular graft infection. Alternatively, some regard Lactobacillus as a contaminant without clinical significance.  In this case, two sets of blood cultures and matching urine culture yielded a clear diagnosis of a causative organism. This is the second reported case of L. jensenii bacteremia with associated nephrolithiasis.

Conclusions: This case exhibits a rare cause of pyelonephritis with associated nephrolithiasis and bacteremia secondary to Lactobacillus jensenii. An ongoing debate over the clinical significance of Lactobacillus cultures has been highlighted in literature, and while many regard Lactobacillus as merely a contaminant, other reports have determined Lactobacillus to be the true pathogen in severe infections. A retrospective review of 200 cases of Lactobacillus infection has found overall mortality rate of nearly 30%. Lactobacillus infection has been associated with recent antibiotic intake, polymicrobial infection, malignancy or immunosuppression. This is the first reported case in which a patient with L. jensenii bacteremia of renal origin and nephrolithiasis did not have one of these associations. The significant mortality profile of Lactobacillus should prompt clinicians to strongly consider it as a culprit pathogen in the appropriate setting.