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A5307 - Recurrent Lactobacillus Bacteremia of Unknown Source
Author Block: J. Samaroo-Campbell1, P. Macauley1, K. Sharma2, P. Jha1; 1Internal Medicine, Maimonides Medical Center, Brooklyn, NY, United States, 2Infectious Disease, Maimonides Medical Center, Brooklyn, NY, United States.
Introduction: Lactobacillus species are facultative anaerobic gram positive organisms that are ubiquitous commensals of the human gastrointestinal and genitourinary tract. They are rarely human pathogens and lactobacillus bacteremia (LB) is often discarded as a contaminant. However, it has been increasingly shown to cause a range of opportunistic infections.
Case Presentation: An 84 year old male with a history of severe aortic stenosis and chronic lymphocytic leukemia presented with complaints of fevers, night sweats and malaise. He was febrile on admission; blood cultures grew Lactobacillus casei and paracasei. Urine culture, CT abdomen/pelvis and TEE did not provide a clear source. During admission patient had severe dental caries requiring 6 tooth extractions. He was discharged to rehab with 4 weeks of IV ampicillin/sulbactam for LB of suspected dental source. Repeat cultures were negative. Probiotics started at rehab.
Two months later he presented with fever and worsening lethargy for two weeks and was started empirically on ampicillin. Blood cultures grew lactobacillus rhamnosus. Gallium scan showed uptake in the prostate with no symptoms of UTI or prostatitis. He was discharged on four weeks of imipenem for LB due to presumed occult prostatitis. Patient was advised to avoid all probiotic containing products.
Four months later he returned with fevers and altered sensorium. Again no source was identified. Blood cultures grew lactobacillus rhamnosus. TEE and CTA chest/abdomen/pelvis did not show vegetations, mycotic aneurysms or fistulous formations. Patient was treated with ampicillin/sulbactam and gentamicin with improvement of symptoms. Repeat cultures were negative and he was discharged with 6 weeks of this regimen.
Conclusion: Literature suggests a link between Lactobacillus species and opportunistic infections in patients with disruption of intestinal barrier, underlying malignancy and structural cardiac disease. These infections most commonly include infectious endocarditis, peritonitis and meningitis with mortality rates as high as 40%. The most commonly identified species are L. rhamnosus and L. casei. Given this high mortality rate, LB in a patient with recurrent fevers and persistent bacteremia should be treated aggressively and not discarded as a contaminant. There is also a role for further studies regarding a link between probiotics and LB, as a source is rarely identified in the majority of cases and the increasing use of probiotics in elderly, potentially vulnerable, populations.