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Listeria monocytogenes


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Listeria Monocytogenes

Listeria Monocytogenes

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  • 2. WHAT IS LISTERIOSIS• Listeriosis, a serious infection causedby eating food contaminated with thebacterium Listeria Monocytogenes, hasrecently been recognized as animportant public health problem in theUnited States.6/3/2013DR.T.V.RAO MD 2
  • 3. WHO GET INFECTED• The disease affects primarilypersons of advanced age, pregnantwomen, new-borns, and adults withweakened immune systems.However, persons without these riskfactors can also rarely be affected.6/3/2013DR.T.V.RAO MD 3
  • 4. WHY IMPORTANT IN HUMAN INFECTIONS• Can cause meningitis andMeingoenphalitis• In particularly in neonates and elderly• Pregnant women - abortions, and stillbirth• Asymptomatic colonization in vaginaproduces infertility6/3/2013DR.T.V.RAO MD 4
  • 5. 6/3/2013DR.T.V.RAO MD 5
  • 6. WHAT IS LISTERIOSIS?• Listeriosis is a serious infection caused by eating foodscontaminated with the bacterium Listeria Monocytogenes.• This disease affects primarily pregnant women,newborn, and adults withweakened immune systems.• This bacterium is too small to be seen without amicroscope.6/3/2013DR.T.V.RAO MD 6
  • 7. LISTERIA MONOCYTOGENES• Small cocal Gram positiveBacteria• Occurs in chains• Long filamentous forms• Tumbling motility at250c and non motile at 370cPeritrichous flagellaAerobic and MicroaerophilicGrowth at 40c6/3/2013DR.T.V.RAO MD 7
  • 8. LISTERIA MONOCYTOGENES• L.monocytogens is aGram + ve non sporeforming.• A specific character ofthe organism manifestwith tumbling end orover end motility at220c – 280c but not at370c6/3/2013DR.T.V.RAO MD 8
  • 9. LISTERIOSIS• Listeriosis is caused byBacterial agent anintracellular pathogenListeria Monocytogenes• L.monocytogens producesinfections world wide• Important cause ofinfections in animals andman.6/3/2013DR.T.V.RAO MD 9
  • 10. CULTURE AND GROWTHCHARACTERISTICS• Grows on Muller Hintonagar with sheep blood asenrichment.• Small zone of Hemolysiscan be observed aroundand the underneath of thecolony.• Specimens are enriched ifthe tissues are kept at 40cand plated on the media( Cold enrichment )6/3/2013DR.T.V.RAO MD 10
  • 11. BIOCHEMICAL REACTIONS• Bacteria arefacultativeanaerobic microbes• Catalase + motile• Listeria produceacid and not gas invarious sugarfermentation tests6/3/2013 DR.T.V.RAO MD 11
  • 12. OTHER CHARACTERS ANDBIOCHEMICAL REACTIONS• Produces hemolytic colonies• Ferments Glucose, Maltose, lactoseproduces acid but no gas• Listeria Monocytogenes present in theenvironment• Saprophyte in soil• Present in water, sewage.6/3/2013DR.T.V.RAO MD 12
  • 13. WHO ARE AT RISK WITH LISTERIOSIS• Pregnant women• New-borns• People with weakened immune systems• People who are taking immuno-suppressing medication.6/3/2013DR.T.V.RAO MD 13
  • 14. HOW HUMANS CONTACT LISTERIOSIS• Listeria Monocytogenes can be found in a variety of dairyproducts, vegetables, fish and meat products.• Listeria Monocytogenes, unlike most other harmfulbacteria, will grow slowly on foods stored in arefrigerator.• Listeria Monocytogenes can also be spread bycontact with an infected product or surface,such as hands or counter tops, during foodpreparation.6/3/2013DR.T.V.RAO MD 14
  • 15. PATHOGENESIS ANDPATHOLOGY• Listeria Monocytogenes enters through the Gastro– intestinal tract after infections of contaminatedfoods such as cheese or vegetables,• The cell wall surface protein called Interanalininteracts with E –CADHERIN and enters intoepithelial cells• Bacteria produce Listeriolysin• L.monocygenes can move from cell to with outbeing exposed toAntibodies,Complement,Polymorphonuclear cells6/3/2013DR.T.V.RAO MD 15
  • 16. WHO ARE AT HIGHER RISK• The following conditions maybe impaired with defective cellmediated ImmunityPregnancyAIDSLymphomasOrgan transplant recipients6/3/2013DR.T.V.RAO MD 16
  • 17. COMMON PRESENTINGMANIFESTATION OF LISTERIOSIS• Vomiting;• Nausea;• Cramps;• Diarrheal;• Severe Headache;• Constipation; or• Persistent fever.6/3/2013DR.T.V.RAO MD 17
  • 18. LISTERIOSIS IN ADULTS• Adults may present withbacteremia .Meingoenphalitis and occurmost commonly inImmunosuppressed patientsin whom Listeria is one of themore common cause ofMeningitis• Disease can be insidious tofulminant6/3/2013DR.T.V.RAO MD 18
  • 19. LATE ONSET MANIFESTATIONS• The new born child maypresent with late onsetsyndrome causes thedevelopment of Meningitisbetween birth and third weekof life• It is often caused by serotypeIV b and has a significantmortality rate6/3/2013DR.T.V.RAO MD 19
  • 20. LISTERIOSIS AND PREGNANCY• Pregnant women -They are about 20times more likely thanother healthy adults toget Listeriosis. Aboutone-third of Listeriosiscases happen duringpregnancy.6/3/2013DR.T.V.RAO MD 20
  • 21. LISTERIOSIS PRESENTING WITHMENINGITIS• Immunocompromised adults are at risk for aserious infection of the blood stream and centralnervous system (brain and spinal cord). Meningitisoccurs in about half of the cases of adultListeriosis. Symptoms of listeria meningitis occurabout four days after the flu-like symptoms andinclude fever, personality change, uncoordinatedmuscle movement, tremors, muscle contractions,seizures, and slipping in and out ofconsciousness.6/3/2013DR.T.V.RAO MD 21
  • 22. LISTERIOSIS IN NEW BORNS• New-borns - New-borns rather thanthe pregnant womenthemselves sufferthe serious effectsof infection inpregnancy.6/3/2013 DR.T.V.RAO MD 22
  • 23. OTHER CLINICAL MANIFESTATIONS• Abscess• Conjunctivitis• Pharyngitis• Urethritis• Pneumonia• Endocarditis• Septicemias6/3/2013DR.T.V.RAO MD 23
  • 24. WHY IMPORTANT IN HUMANINFECTIONS• Can cause meningitis and Meingoenphalitis• In particularly in neonates and elderly• Pregnant women - abortions, and stillbirth• Asymptomatic colonization in vaginaproduces infertility6/3/2013DR.T.V.RAO MD 24
  • 25. DIAGNOSIS• Diagnosisdependent onisolation ofOrganisms incultures obtained onCSF, Blood, andother fluids6/3/2013DR.T.V.RAO MD 25
  • 26. TREATMENT• Ampicillin• Erythromycin• Intravenous Trimethoprim –Sulphmethoxazole• Cephalosporins and Fluroquinoles are not active againstl.monocytogens• A commination of Gentamycin and Ampicillin on clinicalbasis6/3/2013DR.T.V.RAO MD 26
  • 27. 6/3/2013DR.T.V.RAO MD 27
  • 28. • Hot dogs, especially straightfrom the package withoutfurther heating. The fluidwithin hot dog packages maycontain more Listeria than thehot dogs.• Avoid spreading fluid frompackages onto other foods,cutting boards, utensils,dishes and foodpreparation surfaces. Washyour hands after handlinghot dogs.FOODS TO AVOID6/3/2013DR.T.V.RAO MD 28
  • 29. IDEAL WAY TO PREVENTLISTERIOSIS• Completely cook all meats and eggs.• Carefully wash raw vegetables before eating.• Keep raw meat away from raw vegetables and preparedfoods. After cutting raw meat, wash the cutting board withdetergent before using it for vegetables.• Avoid drinking unpasteurized milk or foods made fromsuch milk.• Wash hands thoroughly after handling raw meat.• Follow the instructions on food labels. Observe foodexpiration dates and storage conditions.6/3/2013DR.T.V.RAO MD 29
  • 30. • Programme Created by Dr.T.V.Rao MDfor Medical and Paramedical Students inDeveloping World• Email• doctortvrao@gmail.com6/3/2013DR.T.V.RAO MD 30