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Enjoy!. Don’t forget…. About mycology (not included) Antibiotic Susceptibility Testing (not included) Vaccine lecture information (not included) Last block. ETEC. GNB, Lac+, Ox-, motile, facultative anaerobes Humans fecal-oral, food/H20, non-industrialized countries

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  1. Enjoy!

  2. Don’t forget… • About mycology (not included) • Antibiotic Susceptibility Testing (not included) • Vaccine lecture information (not included) • Last block

  3. ETEC • GNB, Lac+, Ox-, motile, facultative anaerobes • Humans • fecal-oral, food/H20, non-industrialized countries • enterotoxins, Colonizing Factor Antigens • LT, STa • Traveler’s diarrhea-brief, mild-self limiting. Watery Diarrhea, vomiting, cramps, nausea, low grade fever. No blood, no leukocytes, rapid onset 1-5 days • Lac+, McKonkey’s agar • Cephalosporin, Aminoglycoside, TMP-SMX, fluoroquinolone Answer order: Appearance Reservoir Transmission Virulence Toxins Symptoms Diagnosis Treatment

  4. Watery Diarrhea • Where in intestine: • proximal small intes. • Why: • most of water reabs here • What: • ETEC, rota virus, V. cholera, sometimes shigella

  5. Dysentery • Stools • Small, with blood and pus • Where in GI tract is the problem? • Colon • Potential causes • Shigella, EIEC, EntamoebaHistolytica, campylobacter

  6. EHEC • GNB, Lac+, Ox-, motile, fac. Anaer. • Animals (Cattle), unpasteurized milk, raw veggies-spinach • food/H2o, industrialized countries • Shiga Like Toxin I&II, bundle forming pili, attachment/effacement lesions • Shiga-like toxins • 3-4 days after ingestion. Watery diarrhea followed by bloody diarrhea, little or no fever. Hemorrhagic colitis w/ severe ab cramps, leukocytes in 70% cases. Major complication for young and elderly is HUS-SLT II • O157:H7, Sorb- (others sorb+) • Symptomatic Treatment Answer order: Appearance Reservoir Transmission Virulence Toxins Symptoms Diagnosis Treatment

  7. EHEC (STEC) Hemorrhagic colitis Abdominal cramps watery diarrhea grossly bloody diarrhea; usually no fever Colonize surface of intestine; multiply, induce A/E lesions that damage microvilli and alter fluid transport Complication – HUS Produce shiga-like toxin What is this thing called? “Pedestal” Note: attaching bacteria, altered host cell membrane and “pedestal” formation

  8. EHEC (STEC) Hemorrhagic colitis Abdominal cramps watery diarrhea grossly bloody diarrhea; usually no fever Colonize surface of intestine; multiply, induce A/E lesions that damage microvilli and alter fluid transport Complication – HUS Produce shiga-like toxin What is this thing called? “Pedestal” Note: attaching bacteria, altered host cell membrane and “pedestal” formation

  9. How would you treat a patient presenting with O157:H7 infection? Most authorities recommend AGAINST antibiotic therapy for O157:H7 Antibiotic therapy may increase incidence of HUS – due to release of Shiga toxin I the thefluoroquinolones might be the exception here…not sure

  10. 1 2 1 Type 1 pili maybe important in early stages of UTI and may be required to colonize bladder, especially by cystitis strains. P pili – about 80% of E. coli strains from patients with pyelonephritis produce P pili (5X that of fecal strains). P pili appear to be involved in adherence, but are not sole virulence determinant. 2

  11. E. Coli • **ETEC (ST, LT, CFA) human source • EIEC • EPEC • **EHEC (STEC) (O157:H7, etc) animal source • EAEC/DAEC This is just a copy and paste from a lecture slide. Just a reminder to know the details of the ** ones and for the others just that they cause GI problems

  12. ETEC • In the US? • Probably a traveler • We are importing more food so there is increasing outbreaks

  13. E. coli • What is the surface polysaccharide antigen (capsule) common in cases of E. coli meningitis? • K1 • It is a very common cause of meningitis in _____ because of _____? • Meningitis, vaginal spread • Meningitis in neonate…think… • GBS, E. Coli, Listeriamonocytogenes

  14. 1-bacteria 2-bacteria E. coli = most common cause of Gram-negativenosocomial bacteremia 3-bacteria 4-fungus 5-bacteria

  15. Most diarrhea caused by • Viruses. Which ones • Rotavirus, Norwalk • Bacteria-(usually children under 4) • Salmonella • Camp • Shigella

  16. Clinical clues • EHEC-what don’t you have? • fever • ETEC-what do you have? • Nausea and diarrhea only (no vomiting)

  17. 1 2 3 4

  18. Random E. Coli • EAEC and DAEC are major disease causing agents in the US • False-but there was a case at Children’s a while ago • Once causes microvilli elongation one causes microvilli shortening. Diarrhea. • Is E. coli the most common cause of UTIs? • Yes (urethritis, cystitis, pyelonephritis) • When doing this slide I just heard Saelinger say pneumonia in an alcoholic due to Klebsiella will be a test question

  19. EHEC or STEC and hemorrhagic colitis Typically industrialized countries E. coli O157:H7 (sorbitol negative) and other serotypes (sorbitol positive) E. coli O157 sorbitolneg Most E. coli sorbitol fermentation

  20. Page 28 Salmonella General characteristics 1 2 4 3 5

  21. Salmonella typhi & parathypiTyphoid Fever • GNB, Lac-, Ox-, H2S+, motile, facultative anaerobes, facultative intracellular • Humans • fecal-oral ptp, food/h2o, U.S. majority associated w/ travel • Capsule, Siderophore, O and H antigens, crosses M cells taken up by submucosal macrophages, PhoP/PhoQ-intracellular survival, 3% chron carrier in gall bladder • --- • Typhoid Fever: 10-21 day incubation, step like increases in temp (fever 4-8 weeks), mild hepatosplenomegaly, diarrhea, rose spots, GI perforation and/or hemorrhage • Blood, stool, urine, bone marrow • Cipro, Ceftriaxone, TMP-SMX, Zithromax. 10-15% mortality w/o antibiotics. Vaccine of purified capsule polysaccs; live oral atten. vaccine Answer order: Appearance Reservoir Transmission Virulence Toxins Symptoms Diagnosis Treatment

  22. Typhoid Fever (typhi or paratyphi) • There is no fever? • False • Involvement of RES? • True • There is no chronic Carrier State • False • Studied via animal models • FALSE no animal models • What host cell is recruited? • THE MAC • Unfortunately it takes a very small innoculum…? • FALSE-VERY LARGE INNOCULUM

  23. Typhoid fever 2 1 Primary bacteremia – few bacteria, no signs, symptoms Hepatosplenomegaly “Rose spot” rash Facultative intracellular microorganism; survives in macrophages

  24. Typhoid fever – rose spots

  25. Salmonella • GNB, Lac-, Ox-, H2S+, motile, facultative anaerobes • Animals, eggs, meat, fresh produce, peanut butter • Poultry, meat, eggs, fresh produce peanut butter • 2 SPI, invade M cells and enterocytes • Enterotoxin • 6-48 hrs after ingestion. Nausea, vomiting, diarrhea (loose, non-bloody, moderate volume, leukocytes), cramping fever, diarreah resolves in 3-7 days. Bacteremia in 5%. Osteomyelitis, endocarditis, arthritis in 10%. Sever Salmonella sepsis (S. typhimurium) in AIDS pts • Leukocytes in stool offer clue to invasive nature of infection • --- Answer order: Appearance Reservoir Transmission Virulence Toxins Symptoms Diagnosis Treatment

  26. Salmonella • All divided into 2 speceis: all med relevant in Enterica • Human only host? • S. Typhi (typhoid fever) • Animal and Human • S. typhimurium (gastroenteritis)(test question?) • S. Enteritidis (gastroenteritis)

  27. Gastroenteritis • Not associated with poultry. Right? • False • Cytoskeletal rearrangements of M cell only? • FALSE- Enterocytes too!!! • Then released into the lamina propria • Neutrophils recruited • Arachidonic Acid, prostalgandins, leukotrienes, chemokines and increased intracellular calcium-ALTERATION OF ELECTROLYTE BALANCE

  28. Note –PMNs recruited; can be seen in stool What cytokine? 1 Note – macrophages recruited to site What Cytokine 2

  29. Bacteremia • With what serotypes? • Any (watch for this in sickle cell patients, impaired immunity). S. choleraesuis-higher likelihood of causing bacteremia. Aids paiteints=sepsis

  30. Shigelladysenteriae, flexneri, sonei, boydiiShigella • GNB, Lac-, Ox-, H2S-, non-motile, facultative anaerobe • Humans • Fecal-oral, direct contact, food, confinded populations. Flexneri-most common in developing countries. Sonnei most common in developed countries • Virulence plasmid (PAI), Shiga toxin from S. dysenteriae. Taken up by M cell residence in MACS-get into adjacent cells (actin polymerization) • Shiga toxin from S. dysenteriae type 1. • Within 12-48 hrs, average untreated duration is 7 days. Watery diarrhea w/ vomiting and dehydration-prodome or sole presentation. Dysentery-multiple small volume bloody mucoid stools and ab pain. Most serve involvement in colon. Self-limiting. Bacteremia uncommon. HUS (shiga toxin) • Stool Culture (lots of neutrophils), toxin screen • Fluoroquinolones, TMP-SMX Answer order: Appearance Reservoir Transmission Virulence Toxins Symptoms Diagnosis Treatment

  31. p. 29 1 2 3 4 6 5 None

  32. Shigella does not ferment lactose; white colonies

  33. Shigella • Member of what family? • Enterobacteriaceae • It’s Gram Negative • Overt Pathogen • Is it motile? • No • Does not ferment lactose. • Is there H2S production? • No

  34. Shigella • Serotype most frequently seen in the US with most mild presentation • S. sonnei • S.flexneri-developing countries, worse presentation • S. dysenteriae-often fatal epidemics in poor countries • S. boydii-indian subcontinent

  35. Shigella • Survive stomach acid? • Yes, acid resistant • Inoculum • Very low numbers can cause problems (10-100) • Will you have a question on actin polymerization on your test? • Yes.

  36. Ingest organism; stomach small intestine colon Apical surface colon 2Cell type 3 What happens to the MAC? 1 Cytokine 1 Cytokine 4 Process by which the PMN leaves capillary Basolateral surface

  37. Shigella • They have a virulence plasmid and virulence genes encoded on the chromosome. Do they need the plasmid for virulence if they have other genes? • No plasmid=non-invasive • Plasmid has PAI. What virulence genes are on it? • Genes for entry into M cell and epithelial cell • Genes for apoptosis in macrophage • Genes for type III secretion machinery • Is there chronic carriage? • Very very rarely-shed up to 30 days • Shiga and Shiga like toxins are AB toxins that stop protein synthesis and play a role in…. • HUS (usually with S. dysenteriae 1)

  38. What is it? • Bloody diarrhea in the US: • EHEC • In a traveler? • Shigella. S. sonnei hard to differentiate clinically from any other non-bloody diarrhea with fever. • So its hard to say based purely on clinical grounds that S. sonnei is the cause of the bloody diarrhea.

  39. Page 29 2 1 3 4 None 5 6

  40. Campylobacter jejuni (& fetus) • GNB, motile, microaerophillic • Animals (poultry) • Fecal-oral, food • Pathogenesis poorly understood. Ulceration and inflamed bleeding of mucosal surface in jejunum, ileum and colon compatible w/ bacterial invastion. • Pathogenesis poorly understood • 2-4 days incubation, seasonal infections (late summer, early fall), infants have the highest rate of infection, Diarrhea (loose to massive watery to grossly bloody), one of the top 3 common causes of bacterial diarrhea in US • Jejuni grows best at 42 C • Rehydration, erythromycin, quinolones Answer order: Appearance Reservoir Transmission Virulence Toxins Symptoms Diagnosis Treatment

  41. Campylobacter • Another member of the Enterobacteriacea? • Nope • Two groups defined by these two presentations • GI-C. jejuni, C. coli, C. upsaliensis • Extraintestinal infections-C. fetus (more severe) • Association with Guillain-Barre? • C. jejuni

  42. C. fetus – septicemia with dissemination to multiple organs Isolate from blood

  43. Campylobacter species that is usually isolated from the blood • C. fetus • Campylobacter jejuni grows best at what temperature range? • 32-42C

  44. Campylobacter gram negative, curved rod

  45. HelicobacterpyloriUlcers • GN spiral rod, Urease +, highly motile • Human • Person to peron • Lives in protected niche, urease, flagella, VacA, CAG pathogenicity island • VacA • Gastric inflammation-usually asymptomatic. Risk factor for peptic ulcer disease, adenocarcinomas of stomach and primary gastric non-Hodgkin’s lymphoma • Urea breath test, biopsy, urease test, histologic section, culture • Amoxicillin w/ clarithromycin +PPI Answer order: Appearance Reservoir Transmission Virulence Toxins Symptoms Diagnosis Treatment

  46. A bacteria that produces urease • H. pylori • What are its virulence factors? • Urease • Motility • Vac A • Cag A pathogenicity island

  47. VibriocholeraeCholera • G- curved rod, motile, facultative anaerobes • Costal salt water, brackish water, shellfish • Water, shellfish, infected humans • Penetrate mucus layer of small intestine, Adhere, cholera toxin, ToxR, Zonula occluding toxins (endotoxin), siderophores • A5B cholera toxin • 24-48 hr incubation, sudden onset watery diarrhea, voluminous, ricewater stools • Symptoms present, MacConkey or blood agar culture, growth may require salt • Fluid/electrolyte replacement, doxycycline or fluoroquinolones. Vaccines with the whole killed cell, cholera B subunit combo and a live attenuated Answer order: Appearance Reservoir Transmission Virulence Toxins Symptoms Diagnosis Treatment

  48. VibrioCholerae • Is it an Enterobacteriaceae? • Nope • Cholera crosses the intestinal epithelial barrier? • No it attaches to enterocytes • What does its toxin do? • A5B-stimulates adenylatecyclase.

  49. Vibrioparahaemolyticus • GN curved Rod, motile, facultative anaerobes • Costal salt water, estuaries world wide • Seafood • Cytotoxin, hemolysin, adhesion, mucinase • --- • Milder self limiting diarrhea may see cholera like symptoms • MacConkey or blood agar culture, growth may require salt • Doxycycline, fluoroquinolones, antibiotics may have no effect on course Answer order: Appearance Reservoir Transmission Virulence Toxins Symptoms Diagnosis Treatment

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