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  1. 1. Listeriosis Dr.T.V.Rao MD
  2. 2. What is Listeriosis <ul><li>Listeriosis, a serious infection caused by eating food contaminated with the bacterium Listeria monocytogenes , has recently been recognized as an important public health problem in the United States. The disease affects primarily persons of advanced age, pregnant women, newborns, and adults with weakened immune systems. However, persons without these risk factors can also rarely be affected.  </li></ul>
  3. 3. Listeriosis <ul><li>Listeriosis is caused by Bacterial agent an intracellular pathogen </li></ul><ul><li>Listeria Monocytogenes </li></ul><ul><li>L.monocytogenes produces infections world wide </li></ul><ul><li>Important cause of infections in animals and man. </li></ul>
  4. 4. Listeria Monocytogens <ul><li>L.monocytogenes is a Gram + ve non spore forming. </li></ul><ul><li>A specific character of the organism manifest with tumbling end or over end motility at </li></ul><ul><li>22 0 c – 28 0 c but not at </li></ul><ul><li>37 0 c </li></ul><ul><li>But makes the Microbiologists to identify from Diptheriods, which are mistaken and specimens are discarded. </li></ul>
  5. 5. Culture and Growth Characteristics <ul><li>Grows on Muller Hinton agar with sheep blood as enrichment. </li></ul><ul><li>Small zone of Hemolysis can be observed around and the underneath of the colony. </li></ul><ul><li>Specimens are enriched if the tissues are kept at 4 0 c and plated on the media </li></ul><ul><li>( Cold enrichment ) </li></ul>
  6. 6. Biochemcial reactions <ul><li>Bacteria are facultative anaerobic microbes </li></ul><ul><li>Catalase + motile </li></ul><ul><li>Listeria produce acid and not gas in various sugar fermentation tests </li></ul>
  7. 7. Antigenic Classification <ul><li>The important types are </li></ul><ul><li>I a, I b, IV b </li></ul><ul><li>The above types make up 90 % of infections. </li></ul>
  8. 8. Who are at risk with Listeriosis <ul><li>Pregnant women </li></ul><ul><li>Newborns </li></ul><ul><li>People with weakened immune systems </li></ul><ul><li>People who are taking immuno-suppressing medication. </li></ul>
  9. 9. How Humans contact Listeriosis <ul><li>Listeria monocytogenes can be found in a variety of dairy products, vegetables, fish and meat products. </li></ul><ul><li>Listeria monocytogenes , unlike most other harmful bacteria, will grow slowly on foods stored in a refrigerator. </li></ul><ul><li>Listeria monocytogenes can also be spread by contact with an infected product or surface, such as hands or counter tops, during food preparation. </li></ul>
  10. 10. Pathogenesis and Pathology <ul><li>Listeria Monocytogenes enters through the Gastro – intestinal tract after infections of contaminated foods such as cheese or vegetables, </li></ul><ul><li>The cell wall surface protein called Interanalin interacts with E –CADHERIN and enters into epithelial cells </li></ul><ul><li>Bacteria produce Listeriolysin </li></ul><ul><li>L.monocygenes can move from cell to with out being exposed to Antibodies,Complement,Polymorphonuclear cells </li></ul>
  11. 11. Immunity - Listeriosis <ul><li>L Monocytogenes is primarily a intracellular pathogen. </li></ul><ul><li>Immunity to infection is dependent on T cell mediated immunity </li></ul><ul><li>( Cell mediated Immunity CMI ) </li></ul>
  12. 12. Who are at Higher Risk <ul><li>The following conditions may be impaired with defective cell mediated Immunity </li></ul><ul><li>Pregnancy </li></ul><ul><li>AIDS </li></ul><ul><li>Lymphomas </li></ul><ul><li>Organ transplant recipients </li></ul>
  13. 13. Common presenting manifestation of Listeriosis <ul><li>Vomiting; </li></ul><ul><li>Nausea; </li></ul><ul><li>Cramps; </li></ul><ul><li>Diarrhea; </li></ul><ul><li>Severe Headache; </li></ul><ul><li>Constipation; or </li></ul><ul><li>Persistent fever. </li></ul>
  14. 14. Basis of Clinical manifestations <ul><li>Two forms of Perinatal human Listeriosis seen in Major manifestations of Listeriosis </li></ul><ul><li>Early onset syndrome </li></ul><ul><li>( Granulomatosis – Infantiseptica ) </li></ul><ul><li>Infection is result of infection in utero and is disseminated form of disease characterized by neonatal sepsis </li></ul><ul><li>Present with pustular lesions, </li></ul><ul><li>Granulomas contain Listeria Monocytogenes in multiple organs </li></ul><ul><li>Death may occur before or after death </li></ul>
  15. 15. Late onset manifestations <ul><li>The new born child may present with late onset syndrome causes the development of Meningitis between birth and third week of life </li></ul><ul><li>It is often caused by serotype IV b and has a significant mortality rate </li></ul>
  16. 16. Listeriosis In Adults <ul><li>Adults may present with bacterimia . Meingoencephalitis and occur most commonly in Immunosupressed patients in whom Listeria is one of the more common cause of Meningitis </li></ul><ul><li>Disease can be insidious to fulminant </li></ul>
  17. 17. Listeriosis and Pregnancy <ul><li>Pregnant women - They are about 20 times more likely than other healthy adults to get Listeriosis. About one-third of listeriosis cases happen during pregnancy. </li></ul>
  18. 18. Listeriosis in New Borns <ul><li>Newborns - Newborns rather than the pregnant women themselves suffer the serious effects of infection in pregnancy. </li></ul>
  19. 19. Events of Infection with Listeriosis
  20. 20. Listeriosis presenting with Meingitis <ul><li>Immunocompromised adults are at risk for a serious infection of the blood stream and central nervous system (brain and spinal cord). Meningitis occurs in about half of the cases of adult listeriosis. Symptoms of listerial meningitis occur about four days after the flu-like symptoms and include fever, personality change, uncoordinated muscle movement, tremors, muscle contractions, seizures, and slipping in and out of consciousness. </li></ul>
  21. 21. Diagnosis <ul><li>Diagnosis dependent on isolation of Organisms in cultures obtained on CSF, Blood, and other fluids </li></ul>
  22. 22. Risk of Listeriosis with consumed Food
  23. 23. Treatment <ul><li>Ampicillin </li></ul><ul><li>Erythromycin </li></ul><ul><li>Intravenous Trimethoprim – Sulphmethoxazole </li></ul><ul><li>Cephalosporins and Fluroquinoles are not active against l.monocytogens </li></ul><ul><li>A comination of Gentamycin and Ampicillin on clinical basis </li></ul>
  24. 24. CDC – on Listeriosis <ul><li>In 1996, the Centers for Disease Control and Prevention (CDC) began a nationwide food-borne disease surveillance program called &quot;FoodNet,&quot; in which seven states were participating by January 1997. Results from the program indicated that, in 1996, one person out of every 200,000 people got listeriosis. FoodNet also revealed that the hospitalization rate was higher for listeriosis (94%) than for any other food-borne illness. In addition, FoodNet found that the Listeria bacteria reached the blood and cerebrospinal fluid in 89% of cases, a higher percentage than in any other food-borne illness. </li></ul>
  25. 25. Foods to Avoid <ul><li>Hot dogs, especially straight from the package without further heating. The fluid within hot dog packages may contain more Listeria than the hot dogs. </li></ul><ul><li>Avoid spreading fluid from packages onto other foods, cutting boards, utensils, dishes and food preparation surfaces. Wash your hands after handling hot dogs. </li></ul>
  26. 26. Ideal way to prevent Listeriosis <ul><li>Completely cook all meats and eggs. </li></ul><ul><li>Carefully wash raw vegetables before eating. </li></ul><ul><li>Keep raw meat away from raw vegetables and prepared foods. After cutting raw meat, wash the cutting board with detergent before using it for vegetables. </li></ul><ul><li>Avoid drinking unpasteurized milk or foods made from such milk. </li></ul><ul><li>Wash hands thoroughly after handling raw meat. </li></ul><ul><li>Follow the instructions on food labels. Observe food expiration dates and storage conditions. </li></ul>
  27. 27. Created for awareness to Medical and Paramedical students Dr.T.V.Rao MD Email [email_address]