Potential nosocomial acquisition of epidemic Listeria monocytogenes presenting as multiple brain abscesses resembling nocardiosis

Cerebral Abscess Caused by Listeria monocytogenes: Case Report and Literature Review

BACKGROUND

 Listeria monocytogenes is an opportunistic gram-positive, facultative intracellular bacterium that causes invasive diseases mostly in pregnant women and immunosuppressed patients. Despite the predilection toward the central nervous system (CNS), it usually causes meningitis and meningoencephalitis, whereas brain abscesses are very uncommon.

CASE PRESENTATION

 We describe the case of a 69-year-old homeless patient with a brain abscess due to L. monocytogenes who was successfully treated surgically by a guided stereotactic aspiration and antibiotic therapy with ampicillin and gentamicin. Our patient was discharged after 4 weeks of therapy without neurologic deficits. Additionally, we provide a review of the literature of brain abscesses caused by L. monocytogenes.

CONCLUSIONS

 This case highlights the need to drain cerebral abscesses and culture pus to correctly treat patients with antibiotics, especially given the high mortality rate of this infectious entity.

Clinical Presentation and Cranial MRI Findings of Listeria monocytogenes Encephalitis: A Literature Review of Case Series

BACKGROUND

Listeria monocytogenes-associated encephalitis is a severe clinical condition that can also be seen in immunocompetent patients. Clinical manifestation and radiologic features of this entity need to be elaborated.

REVIEW SUMMARY

We searched the medical literature during the period spanning from 1991 to 2017 using the keyword "listeria AND [abscess odds ratio (OR) brainstem OR encephalit* OR magnetic* OR imaging*]." We included in the review well-documented adult cases with a definitive diagnosis and having magnetic resonance imaging data. Confusion, hemiparesis, cerebellar ataxia, facial paralysis, and gait disturbance were the most frequent findings, detected in >30% of patients during admission. The high rate of facial paralysis was of particular interest. T2 hyperintensity (80/82), contrast enhancement (60/82), and ring-enhancing lesions, which are considered as brain abscess, were found in 46/82 patients. The mortality and neurological sequel rates were 20% and 68%, respectively.

CONCLUSIONS

Listeria encephalitis is a severe disease and should be remembered in cases admitted with symptoms related to the brainstem and cranial nerve dysfunction. Cranial magnetic resonance imaging with brainstem and cerebellum involvements and contrast enhancement with or without abscess are particularly suggestive of the listeria-related infection.

Spreading of multiple Listeria monocytogenes abscesses via central nervous system fiber tracts: case report

Animal studies have shown that Listeria monocytogenes can probably access the brain through a peripheral intraneural route, and it has been suggested that a similar process may occur in humans. However, thus far, its spreading through the central nervous system (CNS) has not been completely elucidated. The authors present a case of multiple L. monocytogenes cerebral abscesses characterized by a pattern of distribution that suggested spread along white matter fiber tracts and reviewed the literature to identify other cases for analysis. They elected to include only those cases with 3 or more cerebral abscesses to make sure that the distribution was not random, but rather followed a pattern. In addition, they included those cases with abscesses in both the brainstem and the cerebral hemispheres, but excluded cases in which abscesses were located solely in the brainstem. Of 77 cases of L. monocytogenes CNS abscesses found in the literature, 17 involved multiple abscesses. Of those, 6 were excluded for lack of imaging and 3 because they involved only the brainstem. Of the 8 remaining cases from the literature, one was a case of bilateral abscesses that did not follow a fiber tract; another was also bilateral, but with lesions appearing to follow fiber tracts on one side; and in the remaining 6, to which the authors added their own case for a total of 7, all the abscesses were located exclusively in the same hemisphere and distributed along white matter fiber tracts. The findings suggest that after entering the CNS, L. monocytogenes travels within the axons, resulting in a characteristic pattern of distribution of multiple abscesses along the white matter fiber tracts in the brain. This report is the first description suggesting intraaxonal CNS spread of L. monocytogenes infection in humans following its entry into the brain. This distinct pattern is clearly seen on imaging and its recognition may be valuable in the diagnosis of listeriosis. This finding may allow for earlier diagnosis, which may improve outcome.

Liofilchem(®) O.A. Listeria agar and direct CAMP test provided sooner Listeria monocytogenes identification from neonatal bacteremia

Listeria monocytogenes infection in pregnant women and newborns is a cause for serious concern, and invasive disease outcome strongly depends on prompt antibiotic therapy. To provide sooner identification from neonatal bacteremia we performed a CAMP test directly on positive blood aliquots and inoculated the Liofilchem(®) O.A. Listeria chromogenic agar as well, thus providing a 24-h turn-around time for response.