Genus Listeria. L. monocytogenes

• What is the genus of Listeria?

  Listeria
• What is the species name of Listeria monocytogenes?

  Monocytogenes
• What type of bacteria is Listeria monocytogenes?

  Gram +ve Bacillus
• What does it mean that Listeria monocytogenes is catalase +ve?

  It produces the enzyme catalase
• What is the shape of Listeria monocytogenes?

  Rod-shaped
• What does it mean that Listeria monocytogenes is a facultative anaerobe?

  It can grow with or without oxygen
• What is the biochemical activity level of Listeria monocytogenes?


  Low Biochemical Activity
• What is a characteristic motility feature of Listeria monocytogenes?

  Characteristic tumbling motility in liquid culture
• What type of colonies does Listeria monocytogenes form?

  Small round colonies with narrow zone of beta-haemolysis
• What are common reservoirs for Listeria monocytogenes?

  Unpasteurized milk products and cold deli meats
• How is listeriosis typically acquired?

  Ingestion of contaminated foods
• What is a common food source for congenital listeriosis?

  Transplacental transmission during pregnancy
• What is the incubation period for listeriosis?

  2-4 weeks
• What are the clinical manifestations of listeriosis in healthy adults?

  Self-limiting gastroenteritis
• What symptoms do pregnant women experience with listeriosis?

  Flu-like illness and chorioamnionitis
• What are the potential outcomes of listeriosis in infants?

  Sepsis and neonatal meningitis
• What symptoms do immunocompromised individuals experience with listeriosis?

  Fever, nausea, vomiting, and watery diarrhea
• What are the symptoms of listeria meningitis?

  Neck stiffness and mental status change
• What specimens are used for microbiological diagnosis of listeriosis?

  Blood, CSF, and secretions
• What microscopy technique is used for diagnosing listeriosis?

  Gram staining
• What culture medium is used for listeriosis diagnosis?

  Blood agar culture with thioglycolate medium
• What is the treatment for listeriosis?

  Ampicillin/Penicillin G with Gentamicin
• What are the recommended practices for food safety regarding listeriosis?

  Safe handling, cooking, and consumption of food