Listeria monocytogenes brain abscess on MR imaging mimicking the track of a migrating worm like a sparganum: A case report

Listeria monocytogenes Brain Abscess Mimicking Ischemic Stroke in an Immunocompromised Patient: A Case Report

“…monocytogenes is a Gram-positive bacillus that can cause severe infections to immunocompromised individuals, neonates, and pregnant women. Ingestion of L. monocytogenes-contaminated food, such as raw salads, inadequately cooked meat, and unpasteurized dairy products is the cause of all human L. monocytogenes infections [1,2]. In immunocompetent persons L. monocytogenes rarely causes infections after ingestion of contaminated food, since the host's neutrophils, monocytes, and macrophages will eventually kill it.…”

“…However, if ingested by individuals with impaired immunity, it penetrates the Peyer's patches of the small intestine but not via the phagocytic microfold or M cells [1,3]. More often the organism enters the bloodstream via the mesenteric nodes [1,3] [2,6,8]. Since impaired cellular immunity is a risk factor for the infection, most of the patients concerned-as was the patient presented-are either immunocompromised due to an underlying disease or receiving immunosuppressive therapy [1,3,8,9].…”

“…Treatment can be challenging, requiring a prolonged antimicrobial therapy of uncertain optimal duration, with or without surgical intervention [1,[3][4][5]. They are usually found in the thalamus, pons, and medulla [1,2]. In acute context, when mimicking an ischemic stroke, L. monocytogenes brain abscesses may turn out difficult to be suspected [6].…”

“…Listeria monocytogenes (L. monocytogenes) is a Gram-positive bacillus usually found in food and water, that rarely causes infection in immunocompetent individuals [1,2]. Hematogenous spreading is the main route of the infection, which mainly affects immunocompromised people, neonates, pregnant women and, occasionally, previously healthy persons [1,2].…”

“…When L. monocytogenes-contaminated food such as salads, meat or unpasteurized dairy products is ingested, the bacterium can penetrate the small bowel and it eventually enters the bloodstream via the mesenteric lymph nodes [2,3]. Bacteremia and meningitis are the most common manifestations of listeriosis, but focal infections such as endocarditis, arthritis, and osteomyelitis…”