1 10/6/2015 Enterics Filename: Enterics.ppt

2 10/6/2015 Gram Negative Rods

3 10/6/2015 Cardiobacterium hominis: ä long filaments, pleomorphic / tear drop ä Gentian violet may be retained in ends, sometimes in the middle ä Facultatively anaerobic -- CO2 required ä Strong fermentative reactions (no gas) ä oxidase +catalase + ä No growth on MacConkey, not hemolytic

4 10/6/2015 C.hominis cont’d: ä Found in nasal flora ä Associated with dental disease ä -enter the blood stream and adhere to damaged heart tissue ä causes endocarditis ä -thick polar caps of tufted material

5 10/6/2015 Comparison of Gm Neg rods ä oxidase catalase indole ferment. NO 3 reduc. ä C.hominis ä H.aphrophilus ? ä Actinobacillus ? ä Pasteurella + + most ä Capnocytophaga most + ä Eikenella corrodens

6 10/6/2015 Actinomyces comitans ä Should be differentiated from Kingella ä Prevented by good oral hygiene ä Prophylaxis before dental manipulations

7 10/6/2015 Eikenella ä facultative anaerobic gram negative rod ä E.corrodens -- pits agar (less that 50%) ä normal flora: opportunistic pathogen ä immunocompromised ä slow growing

8 10/6/2015 Eikenella corrodens ä Source ä Human bites ä fist fights. ä Usually untreated ä Complications ä septic arthritis ä osteomyelitis ä meningitis ä brain abscesses ä pneumonia ä lung abscesses ä endocarditis

9 10/6/2015 Calymmatobacterium granulomatis ä Pleomorphic rods, rounded ends, singles or in clusters. ä Single or bipolar condensation of chromatin. ä Exudate from infected tissues -- use Wrights or Giemsa ä stain - characteristic. ä Intracellular organisms in the cytoplasm of large ä mononuclear phagocytes. ä Capsule prominent.

10 10/6/2015 C. granulomatis ä C. (Donovania) granulomatis ä Disease: granuloma inguinale ä Bug: resides in the gut flora. Enters genitals by ä autoinoculation or sexual intercourse. ä Penetrate skin and induce an inflammatory reaction. ä Tissue destroyed ä Antibodies produced. Cell mediated defense ä mechanisms -- important in recovery. This is ä the granulomatous reaction.

11 10/6/2015 Flavobacterium ä Aerobic gram negative rod ä most important: ä Flavobacterium meningosepticum ä found in water, soil, moist reservoirs in the hospital ä Not normal flora of humans ä -opportunists ä Diseases: ä 1/ meningitis ä 2/ septicemia ä Resistant to many antibiotics. ä Most have a yellow pigment. ä Grow on ordinary medium.

12 10/6/2015 S. moniliformis ä Streptobacillus moniliformis ä Causes rat bite fever. ä Found in rats worldwide. ä Transmission: rat bite, consumption of contaminated ä liquid or food. ä Acute onset: high fever, chills, headache, myalgias, ä arthritis. Can reoccur. ä 10% mortality if untreated -- penicillin. ä Culture: serology ä Kits available -- antisera and specific antigen ä Spirillum minor - spiral shaped, can’t be cultured ä Found worldwide, primarily Asia

13 10/6/2015 Enterics

14 10/6/2015 ä Edwardsiella ä Ewingella ä Hafnia ä Serratia ä Salmonella ä Shigella ä Yersinia Enterobacteriaceae ä Escherichia ä Enterobacter ä Klebsiella ä Citrobacter ä Kluyvera ä Proteus ä Providencia ä Morganella

15 10/6/2015 Enterobacteriaceae ä Virulence Factors ä cell wall is an important virulence factor ä Endotoxin or lipopolysaccharide composed of: ä O polysaccharide ä polysaccharide core ä lipid A - which form repeating structural units

16 10/6/2015 Endotoxin ä fever ä leucopenia: leucocytosis ä activation of complement ä thrombocytopenia ä can lead to shock and death

17 10/6/2015 Endotoxins: Pyrogenic Effects ä Pyrogenic - fever producing ä present in virtually every biologic assay system ever examined ä organism present in water systems ä Heat stabile

18 10/6/2015 Enteric Antigenic Phase Variation: ä Antigens: K-capsular & H-flagellar ä Exhibit phase variation expressed under certain conditions.

19 10/6/2015 Enterotoxins Heat stabile ä E.coli, ä Yersinia ä Enterocolitica ä Citrobacter freundii Heat labile ä Shiga Type ä Cholera Type

20 10/6/2015 Shiga Type Enterotoxins Y Verotoxin E. coli Y Shigatoxin Shigella

21 10/6/2015 Cholera Type Enterotoxins ä cholerae type ä V.cholerae is not in Enterobacteriaceae ä E. coli, Salmonella, Klebsiella ä A & B Toxins

22 10/6/2015 Community acquired infections ä E. coli is major cause of urinary tract infections ä also Proteus, Klebsiella, & Enterobacter sp. ä Proteus mirabilis is the major cause of infection related kidney stones ä Klebsiella pneumoniae severe pneumonia

23 10/6/2015 Nosocomial Infections ä 45% of nosocomial Infections in the USA are caused by the Enterobacteriaceae ä Escherichia, Klebsiella, Enterobacter, Serratia, Citrobacter Proteus, Providencia ä Gram negative rods: all found in the indigenous flora most frequently in the intestine E. coli is numero uno

24 10/6/2015 Nosocomial Infections Sites of primary infection ä urinary tract ä lower respiratory tract ä surgical wounds ä blood stream ä skin

25 10/6/2015 Endotoxins : Structure ä Toxic liposaccharide of outer membrane of Gram negative bacteria. Released on destruction of the cell ä O side chains ---Core -- -Lipid A ä oligosaccharides polysaccharide

26 10/6/2015 Escherichia coli

27 10/6/2015 E. coli: Diseases ä Gastorenteritis ä Septicemia ä Urinary Tract Infection ä Neonatal menigitis

28 10/6/2015 E. coli: Septicemia ä Intestinal perforation and disseminated urinary tract infections are the major cause of septicemia.

29 10/6/2015 E. coli: Urinary Tract Infection ä serotypes O4, O6, O75

30 10/6/2015 E. coli: Virulence ä resist killing in serum ä produce hemolysins ä adhere to epithelial cells

31 10/6/2015 E. coli: Antigens ä Antigens O, H, and K. ä certain serotypes are associated with specific diseases

32 10/6/2015 Adhesion ä Most Enterobacteriaceae have Fimbriae ä P fimbriae: E. coli - agglutinate human RBC with P group antigen ä uropathogenic E. coli ä S fimbriae: bind to sialyl galactosides on human erythrocytes ä E. coli that cause neonatal sepsis and meningitis ä

33 10/6/2015 Exotoxins ä Proteins, most potent by unit weight, heat- labile generally. ä Gram positive and Gram negative organisms ä Specific immune effects - antitoxins ä Specific cellular effects

34 10/6/2015 E coli: Neonatal meningitis ä rare in North America ä acquired in birth canal ä virulence associated with K antigen (capsular)

35 10/6/2015 E.coli: Gastroenteritis ä Small Intestine ä enterotoxigenic ä enteropathogenic ä enteroaggregative ä Large Intestine ä enteroinvasive ä enterohemorrhagic

36 10/6/2015 E coli: Small intestine ä Enterotoxigenic ä Traveler’s Diarrhea ä Infant Diarrhea ä Enteropathogenic ä Infant: non-bloody stools ä Enteroaggregative ä Infant: persistant and may have blood in stool

37 10/6/2015 E.coli: Large Intestine ä Enteroinvasive ä watery, then dysentery-like ä Enterohemorrhagic ä hemorrhagic colitis

38 10/6/2015 Escherichia coli ä common in large numbers in intestine of mammals and many other warm blooded animals

39 10/6/2015 E.coli: Epidemiology North America & Western Europe ä most commonly associated with endogenous infections (urinary tract infections most frequent) ä Gastroenteritis not as common as endogenous diseases Countries with poor hygiene ä bacterial sepsis ä neonatal meningitis ä gastroenteritis

40 10/6/2015 E. Coli: Pathogenicity ä Enteropathogenic ä Enterohemorrhagic

41 10/6/2015 Enteropathogenic E.coli ä Adhere to cells of small intestine. Also called enteroadherent. One of the adherence factors is plasmid mediated.

42 10/6/2015 Enterohemorrhagic E coli ä hemorrhagic Gastroenteritis ä hemolytic Uuremic Syndrome

43 10/6/2015 Hemorrhagic gastroenteritis ä Shiga-like toxin : half of the E. coli that cause the diseases are serotype 0157:H7. ä Hemorrhagic gastroenteritis: mild to severe, mostly in children < 5, undercooked ground beef and unpasteurized milk.

44 10/6/2015 Hemolytic uremic syndrome: ä acute renal failure, thrombocytopenia, microangiopathic (small blood vessels), hemolytic anemia. Drop in blood cells due to hemolysis of red cells in small blood vessels.

45 10/6/2015 The End

46 10/6/2015 Short Answers ä Construct a table of the virulence factors associated with ??? and the biological activity of each ä Use a series of no more than four diagrams to describe the mechanism of ??? activity ä Describe the clinical manifestions ??? ä Construct a table listing the common ??? species and the associated human diseases.