Listeria monocytogenes

  • Diagnosis
  • Background
  • Lab Tests
  • References
  • Related Topics

Indications for Testing

  • High level of suspicion coupled with symptoms in at-risk patients

Laboratory Testing

  • CDC – diagnosis and  testing recommendations
  • Rapid detection tests may be available (monoclonal antibodies or nucleic acid hybridization) but may only identify genus Listeria
  • Culture
    • Blood
    • CSF
    • Amniotic fluid
    • Maternal/fetal tissues

Differential Diagnosis

Listeria monocytogenes is the causative agent of Listeriosis and is transmitted through contaminated foods. Listeriosis is a virulent foodborne illness with 20-30% mortality, especially in immunocompromised individuals.

Epidemiology

  • Prevalence – ~1,600 people/year in U.S. infected (CDC, 2016)

Organism

  • Gram-positive facultative, intracellular rods
  • Hardy organism – capable of growing at both 4ºC and 37ºC
  • Organisms are motile by means of flagella at room temperature, but not at 37ºC (body temperature); can spread from cell to cell via actin polymerization
  • L. monocytogenes is the only recognized human pathogen in Listeria species and has >14 serotypes​
  • Infection usually follows eating contaminated food (listeria can grow and multiply in a refrigerated state)
    • Uncooked meats and vegetables
    • Unpasteurized milk and cheeses
    • Processed foods (eg, soft cheeses, processed meats, smoked seafood)

Risk Factors

Clinical Presentation

  • Initial symptoms – fever, muscle aches, nausea, diarrhea
  • Localized infection
    • Skin
    • Intra-abdominal
  • More serious symptoms may develop if infection spreads
  • Manifestations in pregnancy
Tests generally appear in the order most useful for common clinical situations. Click on number for test-specific information in the ARUP Laboratory Test Directory.

Cerebrospinal Fluid (CSF) Culture and Gram Stain 0060106
Method: Stain/Culture/Identification

Blood Culture 0060102
Method: Continuous Monitoring Blood Culture/Identification

Limitations 

Testing is limited to the University of Utah Health Sciences Center only

Body Fluid Culture and Gram Stain 0060108
Method: Stain/Culture/Identification

Limitations 

Anaerobe culture is NOT included with this order

Listeria Antibody, Serum by CF 0099529
Method: Semi-Quantitative Complement Fixation

Listeria Antibody, CSF by CF 2002086
Method: Semi-Quantitative Complement Fixation

General References

Allerberger F, Wagner M. Listeriosis: a resurgent foodborne infection. Clin Microbiol Infect. 2010; 16(1): 16-23. PubMed

Bortolussi R. Listeriosis: a primer. CMAJ. 2008; 179(8): 795-7. PubMed

Drevets DA, Bronze MS. Listeria monocytogenes: epidemiology, human disease, and mechanisms of brain invasion. FEMS Immunol Med Microbiol. 2008; 53(2): 151-65. PubMed

Gandhi M, Chikindas ML. Listeria: A foodborne pathogen that knows how to survive. Int J Food Microbiol. 2007; 113(1): 1-15. PubMed

Posfay-Barbe KM, Wald ER. Listeriosis. Semin Fetal Neonatal Med. 2009; 14(4): 228-33. PubMed

Ramaswamy V, Cresence VM, Rejitha JS, Lekshmi MU, Dharsana KS, Prasad SP, Vijila HM. Listeria--review of epidemiology and pathogenesis. J Microbiol Immunol Infect. 2007; 40(1): 4-13. PubMed

Medical Reviewers

Last Update: August 2016