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Enterobacteriaceae Slackers Facts by Mike Ori. Disclaimer The information represents my understanding only so errors and omissions are probably rampant.

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Presentation on theme: "Enterobacteriaceae Slackers Facts by Mike Ori. Disclaimer The information represents my understanding only so errors and omissions are probably rampant."— Presentation transcript:

1 Enterobacteriaceae Slackers Facts by Mike Ori

2 Disclaimer The information represents my understanding only so errors and omissions are probably rampant. It has not been vetted or reviewed by faculty. The source is our class notes. The document can mostly be used forward and backward. I tried to mark questionable stuff with (?). If you want it to look pretty, steal some crayons and go to town. Finally… If you’re a gunner, buck up and do your own work.

3 Enterobacteriacea characteristics

4 Rapidly growing large gram negative rods of various sizes that can grow on plain agar both aerobically or anaerobically.

5 Enterobacteriaceae antigens

6 O: outer membrane lipopolysaccharide H: flagellar K: cell surface polysaccharides

7 Enterobacteriacaea common pathogens

8 Escherichia Shigella Salmonella Klebsiella Yersinia

9 Enterobacteriaceae uncommon pathogens

10 Enterobacter Serratia Proteus Morganella Providencia

11 Most common Enterobacteriaceae species

12 Escherichia coli

13 Enterobacteriaceae dedicated pathogens

14 Shigella Salmonella

15 E Coli type 1 pili characteristics

16 Pili that mediates general attachment to a wide variety of epithelial cells via adhesins that interact with host D-mannose residues

17 E. Coli P pili characteristics

18 Pili that interact with digalactose (gal-gal) residues on uroepithelium thus allowing efficient colonization of the urinary tract.

19 E. coli colonizing factor antigen (CFA) or bundle forming pilin (BFP) characteristics

20 Pili that mediate attachment to enterocytes

21 E. Coli alpha hemolysin toxin

22 Pore forming exotoxin

23 Shiga toxin

24 Interferes with protein synthesis: An A-B toxin secreted by E. coli whose active unit interferes with protein synthesis by blocking the ribosomal amino acyl tRNA binding site. Causes hemolysis by unknown mechanisms. Interferes with kidney function: Circulating toxin binds renal tissues causing glomerular swelling and the deposition of fibrin and platelets into the microvasculature.

25 Labile toxin

26 Cholera-like A-B toxin generated by some E. coli strains that increases cAMP production in host cells by ADP-ribosylation of Gas

27 Stable toxin

28 Cholera-like (A-B?) toxin generated by some E. coli strains that increases cGMP production by host cells

29 E. Coli fancy smancy names

30 UPEC – uropathogenic EC ETEC – enterotoxigenic EC EPEC – enteropathogenic EC EHEC – enterohemorrhagic EC EIEC – enteroinvasive EC

31 E. Coli UTI causation %

32 90% of UTIs

33 UTI common patient

34 Sexually active women

35 E. Coli UTI pathogenicity factors

36 Type 1 pili mediate binding in periurethral area. P pili mediate attachment to urogenital cells.

37 ETEC characteristics

38 Watery diarrhea caused by labile/stable toxins with bacterial attachment facilitated by CFA (colony factor antigen) pili. All of the above are plasmid borne.

39 ETEC epidemiology

40 Significant cause of mortality in children 2 and younger in less developed countries. Common cause of traveler’s diarrhea. Human reservoir. Point to ponder: What kind of diarrhea would the time traveler’s wife’s husband have?

41 ETEC symptoms

42 Watery diarrhea

43 EPEC characteristics

44 Bundle forming pili (BFP) bearing intimin protein mediate attachment of the cells to host enterocytes. Subsequent injection of E. coli secretion proteins (Esp) causes the formation of a pedestal by modifying the cytoskeleton.

45 Attachment and effacing lesion

46 Lesion caused by EPEC and EHEC E. coli strains by injection of E. coli secretory proteins (Esp) that results in the effacement of enterocyte microvilli and the attachment of E. coli at the top of pedestals formed from commandeered cytoskeletal components.

47 Whats the coolest thing about intimin

48 E. coli injects the receptor for intimin along with E. coli secretion proteins (Esp)

49 EPEC epidemiology

50 Common in less developed countries where it accounts for 20% of the diarrhea in bottle fed infants below 1 year of age.

51 EPEC symptoms

52 Watery diarrhea

53 EHEC characteristics

54 Resembles EPEC in that it creates attaching and effacing lesions. Notably different however is its secretion of shiga toxin.

55 EHEC symptoms

56 Bloody diarrhea and hemolytic uremic syndrome

57 EHEC epidemiology

58 More common in industrialized nations with industrialized meat packing practices. Outbreaks arise from undercooked meat and cross contamination of produce.

59 EHEC inoculating dose

60 organisms

61 EHEC serotype

62 O157:H7

63 EPEC EHEC differences

64 EHEC elaborates shiga toxin. EPEC prefers the small intestine EHEC prefers the colon

65 EIEC characteristics

66 Virtually identical to shigella except that is has a lower incidence of person to person transmission. Likes silent brooding types, strong chins, and long walks on the beach.

67 EIEC epidemiology

68 Virtually restricted to children 5 or younger. Humans are the only known reservoir.

69 ETEC and EPEC disease course

70 Self limiting watery diarrhea that clears within a few days

71 EHEC timecourse

72 Initial watery diarrhea lasting 1-2 days followed by intense abdominal pain and bloody diarrhea that resolves in 3-10 days.

73 Hemolytic uremic syndrome symptoms

74 Occurs in EHEC cases primarily in children < 10 years old. Oliguria, edema, and palor followed by hemolytic anemia, thrombocytopenia, and renal failure.

75 EHEC culture diagnosis

76 Does not ferment sorbitol. Grow out on MacConkey agar and then subject to O157 antisera.

77 EHEC treatment

78 Supportive care including hemodialysis and hemapheresis if HUS is present (hooray for h). Do not use abx or antimotility agents.

79 ExEC general guidelines

80 Supportive care is mainstay Replace fluids with oral rehydration therapy or IV if necessary. Abx for ETEC, EIEC, EPEC but NOT for EHEC Antimotility agents if you have to for EPEC and ETEC but NOT for EIEC of EHEC

81 Shigella characteristics

82 Acid resistant (not acid fast) gram negative rod transmitted by person to person contact under conditions of poor sanitation which causes disease that begins with watery diarrhea and evolves into dysentery type diarrhea.

83 Shigella species and types

84 Four species (A-D). Group D has 38 antigenic types of O antigen

85 Shigella epidemiology

86 Spread by direct person to person contact under conditions of poor personal or community sanitation. Small infecting dose of less than 200 organisms insures efficient transmission. The reservoir is human

87 S dysenteriae epidemiology

88 Largely limited to underdeveloped nations with type 1 producing the most severe disease.

89 Shigella invasion target cells

90 Adherence to and transcytosis through M cells to reach underlying phagocytic cells.

91 Invasin protein antigen (Ipa) function

92 Proteins injected into host cells by shigella using a contact initiated injection system. These proteins have a wide range of function including cytoskeletal rearrangement, actin polymerization, and apoptosis

93 Shigella intracellular movement mechanism

94 Moves via actin polymerization of host actin filaments. Creates a characteristic actin “comet” tail.

95 What other bacteria invades in a manner similar to shigella

96 Listeria Why is shigella so popular at parties? Because its lysterical.

97 Shigella mucosal damage characteristic

98 Focal ulcers in the mucosa

99 Shigella diarrhea characteristics

100 Small volume stools containing WBC’s, RBC’s, and bacteria.

101 Shigella toxin elaboration characteristics

102 Not all strains elaborate shigella toxin but doing so correlates with disease severity. S dysenteriae type 1 elaborates Stx. If Stx is elaborated systemic effects of Stx can occur as can HUS.

103 Shigella diagnosis

104 Labs routinely screen for shigella. No other details were provided.

105 Shigella treatment

106 Generally self limiting however abx decrease duration of disease and the contagious period.

107 Shigella clinical triad

108 Cramps Tenesmus Frequent small volume, bloody, mucoid discharge

109 Salmonella characteristics

110 Gram negative facultative anaerobe with a wide range of serovars based on O,H,K typing. Disease for any given serovar may be restricted to humans, animals, or both.

111 Salmonella food poisoning characteristics

112 Picnics, warm summer days, drunken co- workers, contaminated food, logarithmic growth, You didn’t eat the potato salad did you? You did? Damn! 2 day incubation, 3-4 days of suffering. See you next year.

113 Salmonella inoculating dose

114 10000 or more

115 Salmonella outbreak epidemiology

116 Cross contamination from poultry, exotic pets, or humans particularly in the context of modern industrial food plants.

117 Salmonella infection path

118 Cellular transcytosis to invade lamina propria

119 Salmonella cytoskeletal rearrangement pattern

120 Ruffling occurs within minutes of contact. This results in pinocytosis of the bacterium.

121 Human only serovar of Salmonella

122 Typhi

123 What is a common carrier organ for typhi?

124 Gall bladders

125 Classic Victorian novel disease caused by typhi

126 Died of fever

127 Typhi disease cycle

128 Invasion of mucosa Ingestion by macrophages but escape of killing by interfering with oxidative burst/lysosome fusion (??) Travel to secondary lymphoid tissues Rupture of macrophages Dissemination of bacteria Dissemination of LPS endotoxin resulting in fever

129 Typhoid fever course

130 Resolution within about 3 weeks Or Death

131 Enteric fever cause

132 Disseminated Salmonella

133 Disseminated Salmonella sites

134 Osteomyelitis of long bones Sepsis Biliary tree (typhoid Mary?)

135 Salmonella diagnosis

136 Similar to shigella. Culture from blood early in enteric fever.

137 Salmonella gastroenteritis treatment

138 Supportive care Anti nausea and anti vomiting drugs Do not use abx as these prolong carrier state

139 Enteric fever treatment

140 TMP-SMX or other abx to which the strain is susceptible

141 Klebsiella characteristics

142 Polysaccharide encapsulated enterobacteriaceae species that causes a classic lobar pneumonia.


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