2010-20112nd Term 2nd Semester
Haemophilus Spp (Blood-loving bacteria) H. Influenzae    Does not cause influenza, Why named so?      mistakenly consid...
H. Influenza have no                                               specific syndrome but                                  ...
One of the most transformable genomes H. Influenza was the first free living organism to have the  complete genome sequen...
Diagnosis Microscopy to detect in CSF, synovial fluids, Culturing, difficult, may be not sensitive latex particle agglu...
Treatment and prophylaxis cefotaxime , ceftriaxone, ampicillin and sulbactam,  cephalosporins of the second and third gen...
Vibrio  V. cholerae, and V. parahaemolyticus are human pathogensV. cholerae: cause cholera. Comma shaped rods , with Two  ...
Sack, David, et al. 2004. Seminar: Cholera. The Lancet. 363: 223-233.
Diagnosis Rapid tests    Dark-field microscopy    Rapid immunoassays    Molecular methods – PCR & DNA probes Selectiv...
Helicobacter           H. pylori = gastritis, peptic ulcer                     disease(PUD) Helical (spiral or curved) co...
 Diagnostic aspects   Detected in endoscopic antral gastric biopsy material   Culture media containing whole or lysed b...
Mycobacterium tuberclosis: Tuberclosis 1/3RD of World has it, a                     global Emergency.             TB what ...
Symptoms for Pulmonary TB:There are many types of Tuberclosis, pulmonary              is most important  Perpetual Cough ...
Some diagnostics Acid fast staining, and Lowenstein-Jensen Agar Skin test- Mantoux test Purified Protein Derivative PPD...
Treatment and prevention Take antibiotics for 6-12 months Preventative drug to destroy dormant bacteria For active TB, ...
Mycobacterium leprae, Leprosy (uncommon)
Spirochetes:      Treponema, Borrelia, & Leptospira Spirochete means “coiled hair” Greek. They are  tightly coiled like t...
Spirochaetes: Genus Treponema Genus: Treponema: Treponema pallidum, causes syphilis (sexually, or congenitally transmitte...
Spirochetes Genus: Borrelia   Borrelia burgdorferi,     Causes a zoonotic vector borne disease called Lyme disease    ...
Treatment and control Penicillin remains drug of choice   • WHO monitors treatment recommendations   • 7-10 days continuo...
Rickettsial Diseases              Transmitted by Arthropod Vectors Fastidious, obligate intracellular bacteria that grow ...
Rickettsial Diseases                       1. Spotted Fever Group                                  Mediterranean spotted ...
2. Typhus Group Murine typhus – Rickettsia mooseri (typhi) Epidemic typhus – Rickettsia prowazekii Scrub typhus – Ri...
3. Others Q Fever – Coxiella burnetii • Ehrlichiosis – Ehrlichia canis – Ehrlichia equi – Ehrlichia chafeensis – Se...
Pathogenesis and Clinical Symptoms Pathogenesis for all these infections is very similar regardless  of species. A vascul...
Four Prototype Diseases 1. Rocky Mountain spotted fever… by Rickettsia rickettsii    Fever, heache, rash… 2. Murine typ...
Weil-Felix Reaction           and the bit of a history Historical known that Proteus antibodis cross-reactive  with sever...
Diagnosis and treatmentSpecific & sensitive tests:    Indirect immunofluorescent antibody (IFA)    Indirect hemagglutina...
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2nd term lecture,_,vib,_helico,tb,_spiro,rick[1]

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2nd term lecture,_,vib,_helico,tb,_spiro,rick[1]

  1. 1. 2010-20112nd Term 2nd Semester
  2. 2. Haemophilus Spp (Blood-loving bacteria) H. Influenzae  Does not cause influenza, Why named so?  mistakenly considered the cause of influenza 1890 Pandemic.  Gram negative coccobacilli  Obligate parasites of man  Cause hidden disease because:  Does not cause a specific disease  Responding first with antibiotics may mask Hibs  Difficult to isolate  Fastidious, require X (hemine) and V (NAD or NADP) factors in chocolate agar A "Rapid Assessment Tool" has been developed by WHO and CDC to make sensible estimates of Hib H. Ducreyi : STD (soft chancroid) not common Opportunistic Haemophilus pathogens are rare
  3. 3. H. Influenza have no specific syndrome but can cause: meningitis, conjunctivitis, sinusitis, cellulitis, otitis, epiglottitis, pneumonia,Health Canada and www.cdc.gov/vaccines/pubs
  4. 4. One of the most transformable genomes H. Influenza was the first free living organism to have the complete genome sequenced in 1995 The genome consists of 1.8 MB of DNA in a single circular chromosome of which 1.7 code for proteins. How does it become highly-specific to humans?.  Mutations,Transformable by many ways,  Phase variation by DNA repeats
  5. 5. Diagnosis Microscopy to detect in CSF, synovial fluids, Culturing, difficult, may be not sensitive latex particle agglutination test (LAT) PCR H.Influenza Gram stain H.Influenza Choclate agar
  6. 6. Treatment and prophylaxis cefotaxime , ceftriaxone, ampicillin and sulbactam, cephalosporins of the second and third generation, or fluoroquinolones are preferred. Hib conjugate vaccine Hib is preventable, but there are two problems:  A shortage of information : difficult to diagnose, it causes death without being recognized  Expensive: Hib vaccine is expensive
  7. 7. Vibrio V. cholerae, and V. parahaemolyticus are human pathogensV. cholerae: cause cholera. Comma shaped rods , with Two circular chromosomes  What is Cholera? Cholera toxin activates adenyl cyclase causing increased cAMP level and hypersecretion of fluids and electrolytes  Extensive watery diarrhea (15-20 liters/day) called Rice-Water Stool: Colorless Odorless No protein Speckled with mucus Source contaminated waters and food Caused 8 cholera pandemics, example of Pandemic strain is El Tor Treatment and prevention Rehydration & supportive therapy Water purification, sanitation & sewage treatment Vaccines
  8. 8. Sack, David, et al. 2004. Seminar: Cholera. The Lancet. 363: 223-233.
  9. 9. Diagnosis Rapid tests  Dark-field microscopy  Rapid immunoassays  Molecular methods – PCR & DNA probes Selective/differential culture medium - Thiosulfate Citrate Bile salts Sucrose (TCBS) agar  V. cholerae grow as yellow colonies Biochemical and serological tests
  10. 10. Helicobacter H. pylori = gastritis, peptic ulcer disease(PUD) Helical (spiral or curved) corkscrew shape and lophotrichous (tuft at one pole)flagella helps in penetration and colonization of mucosal lining of stomach & duodenum Acid-inhibitory protein Hydrolyzes urea and inhibits acids in gastrics • Most gastric cancers are preceded by an infection with H. pylori Microaerophilic: Change chape to coccoid when exposed to oxygen or upon prolonged culture
  11. 11.  Diagnostic aspects  Detected in endoscopic antral gastric biopsy material  Culture media containing whole or lysed blood  Microaerophilic  does not ferment or oxidize carbohydrates Triple Chemotherapy (synergism):  Proton pump inhibitor (e.g., omeprazole = Prilosec(R))  One or more antibiotics (e.g., clarithromycin; amoxicillin; metronidazole)  Bismuth compound
  12. 12. Mycobacterium tuberclosis: Tuberclosis 1/3RD of World has it, a global Emergency. TB what it is, and how it spreads?Outside body Inside body:Spreads through the air when a person with TB:  bacilli go to lungs and infect alveoli Coughs  Macrophages attack bacteria, but some survive Speaks  Infected macrophages form tubercles  Dead cells form granulomas Laughs Sneezes Sings http://www.cpmc.columbia.edu/resources/tbcpp/abouttb.html.
  13. 13. Symptoms for Pulmonary TB:There are many types of Tuberclosis, pulmonary is most important  Perpetual Cough  Fever  Weight loss  Night sweats Types of TB bacteria include: Mycobacterium tuberculosis  Loss of appetite Mycobacterium leprae  Fatigue Mycobacterium avium  Swollen glands  Chills  Pain while breathing
  14. 14. Some diagnostics Acid fast staining, and Lowenstein-Jensen Agar Skin test- Mantoux test Purified Protein Derivative PPD injected in forearm and examined 2-3 days later Red welt around injection indicates infection Examine medical history, x-rays, and sputum
  15. 15. Treatment and prevention Take antibiotics for 6-12 months Preventative drug to destroy dormant bacteria For active TB, 4 medications: isoniazid, rifampin, ethambutol, and pyrazinamide Vaccines (relatively ineffective today) Check with X-ray
  16. 16. Mycobacterium leprae, Leprosy (uncommon)
  17. 17. Spirochetes: Treponema, Borrelia, & Leptospira Spirochete means “coiled hair” Greek. They are tightly coiled like telephone cord, only a fraction of a micron in diameter but hundred of microns long Twisting Motility by periplasmic flagella (axial fibrils or endoflagella) is a major difference between this and other bacteria
  18. 18. Spirochaetes: Genus Treponema Genus: Treponema: Treponema pallidum, causes syphilis (sexually, or congenitally transmitted), delicate obligate parasite Stages of Syphilis:  1. Primary Chancre lesion is the main sign  2. Secondary rash  3. Latent , no sign but bacteria present  4.Tertiary, very complicated systemic Treponema pertenue, causes yaws skin lesion
  19. 19. Spirochetes Genus: Borrelia  Borrelia burgdorferi,  Causes a zoonotic vector borne disease called Lyme disease  Transmitted by ticks  Linear chromosome  Borrelia recurrentis, causes relapsing fever Genus: Leptospira  Leptospira species, causes leptospirosis Main Diagnostic tests for Spirochetes:  Darkfield microscopy  Fluorescent antibody staining  VDRL  Wasserman Test  Hemagglutination tests
  20. 20. Treatment and control Penicillin remains drug of choice • WHO monitors treatment recommendations • 7-10 days continuously for early stage • At least 21 days continuously beyond the early stage Prevention of Mother-child transfer by barrier methods (e.g., condoms) Prophylactic treatment of contacts identified through epidemiological tracing Cautiousness, and morals play significant roles
  21. 21. Rickettsial Diseases Transmitted by Arthropod Vectors Fastidious, obligate intracellular bacteria that grow only on cells, eggs, and tissue cultures Transmitted by Arthropod Vectors They are pleomorphic & coccobacillary Do not show on Gram stain, but can be seen with either Gimenez or Giemsa stains Gimenez stain of tissue culture cells infected with Rickettsia rickettsii
  22. 22. Rickettsial Diseases 1. Spotted Fever Group  Mediterranean spotted fever Rocky Mountain spotted fever  – Rickettsia conorii – Rickettsia rickettsii  Siberian tick typhus Rickettsial pox  – Rickettsia siberica – Rickettsia akari  Queensland tick typhus Canadian typhus  – Rickettsia australis – Rickettsia canada
  23. 23. 2. Typhus Group Murine typhus – Rickettsia mooseri (typhi) Epidemic typhus – Rickettsia prowazekii Scrub typhus – Rickettsia tsutsugamushi
  24. 24. 3. Others Q Fever – Coxiella burnetii • Ehrlichiosis – Ehrlichia canis – Ehrlichia equi – Ehrlichia chafeensis – Several others now identified
  25. 25. Pathogenesis and Clinical Symptoms Pathogenesis for all these infections is very similar regardless of species. A vasculitis (inflammation of blood vessel wall) is caused by the invasion and multiplication of the organism in the endothelial and smooth muscle cells of the blood vessels.Clinical symtoms Thrombosis, occlusion, and necrosis of blood vessel walls Thrombocytopenia with hemorrhage  – occurs primarily as a result of platelet consumption as opposed to true (DIC)disseminated intravascular coagulation Massive capillary leakage, edema, hypotension, and respiratory distress, encephalitis, myocarditis, & nephritis
  26. 26. Four Prototype Diseases 1. Rocky Mountain spotted fever… by Rickettsia rickettsii  Fever, heache, rash… 2. Murine typhus…by Rickettsia typhi 3. Epidemic typhus …by Rickettsia prowazekii 4. Q fever…by Coxiella burnetii  Occurs in veterinarians, ranchers, and animal researchers from infected placenta of sheep, cattle, or goats (no arthropod vector for C. burnetii). Pneumonia is common
  27. 27. Weil-Felix Reaction and the bit of a history Historical known that Proteus antibodis cross-reactive with several of the rickettsiae. Today, Weil-Felix test is not confirmed for rickettsial infection. In Poland during World War II, two physicians cleverly used killed Proteus bacteria to vaccinate the men of a small town, to induce a positive Weil-Felix reaction. The occupying Germans feared typhus epidemic and Due the vaccination reaction, the village was saved of a certain destruction. The men were not forced into the army, and the women and children were not forced into the camps.
  28. 28. Diagnosis and treatmentSpecific & sensitive tests:  Indirect immunofluorescent antibody (IFA)  Indirect hemagglutination antibody (IHA)  Complement fixation (CF)Treatment In life-threatening rickettsial infections, early antibiotic intervention is recommended to prevent endothelial damage Doxycycline, tetracycline, and chloramphenicol are the drugs of choicePrevention (transmitted by vectors so avoid them)  Use of repellents & protective clothing in endemic areas  Inspection & removal of ticks  Vaccine for RMSF is available for risk groups  Weekly doxycycline

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