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Flashcards in Gram negative pathogens (complete) Deck (110):
1

What are the Gram-negative pathogens we study

1. Neisseria species
2. Escherichia Coli
3. Shigella species
4. Salmonella species
5. Klebsiella pneumoniae
6. Yersina species
7. Bordetella pertussis
8. Pseudomonas aeruginosa
9. Francisella tularenesis
10. Legionella pneumophila

2

What group is the largest group of human pathogens and why

Gram-negative bacteria, in part because of the Lipid A in their cell wall

3

What does Lipid A trigger in humans

Fever, vasodilation, inflammation, shock, and disseminated intravascular coagulation (blood clots in blood vessels)

4

What are the three things that any gram-negative bacteria needs to cause disease or death in humans

1. breach the skin or mucus membranes
2. grow at 37 degrees celcius
3. evade the immune system

5

What is the only Gram-negative Cocci that regularly causes diseases in humans

Neisseria

6

What do Neisseria usually look like

gram-negative diplococci, in pairs, with flattened sides

7

are neisseria aerobic or anaerobic

aerobic

8

What are the two pathogenic types of neisseria

neisseria gonorrhea
neisseria meningitidis

9

neisseria are pyogenic, or pyrogenic

pyogenic (pus creating)

10

What is the isolation media used for neisseria

chocolate agar, + increased CO2

11

What is the major virulence factor of neisseria gonorrhea

the attachment pili

12

what is the most common reportable disease is the US

gonorrhea

13

What happens to males with gonorrhea

infection of the anterior urethra = acute inflammation
pus discharge and painful urination
can cause rectal or pharyngeal infections also

14

What happens to females with gonorrhea

infection of vaginal-cervical junction
80% of infections are asymptomatic
may cause salpingitis
may spread to lower abdomen and cause Pelvic Inflammatory Disease (PID)

15

What is salpingitis

a gonorrhea infection of the fallopain tubes (20% sterility rate)

16

What happens to children with gonorrhea

as they pass through the birth canal they can contrat gonococcal opthalmia neonarum (eye infection)

17

What is done to prevent gonococcal opthalmia neonarum

antibiotic ointments placed in the eyes of newborns

18

What is neisseria gonorrhea transmitted

sexual contact

19

which age group has the highest incidence of neisseria gonorrhea

20-24

20

How is gonorrhea diagnosed

by the symptoms, and observation of the organisms in the pus

21

What is the treatment for gonorrhea

used to be penicillin, but not it has 50% resistance
now it is cephalosporin + tetracycline

22

how is gonorrhea prevented

controlling sexual behavior

23

Where can you find neisseria meningitidis

only in humans (normal microbiota of the upper respiratory tract)

24

What is the problem with neisseria meningitidis

when the bacteria gets in the blood or cerebrospinal fluid it becomes life threatening meningitis

25

neisseria meningitidis is the most common cause of meningitis in individuals _____

under 20

26

How is neisseria meningitidis transmitted
how How

respiratory droplets among people living in close contact (dorms and barracks)

27

What are the two diseases associated with neisseria meningitidis

meningococcal meningitis
meningococcal septicemia

28

how quickly can meningococcal meningitis go from initial symptoms to death

6 hours

29

what is meningococcal septicemia

blood poisoning by neisseria meningitidis. produces blood coagulation and the formation of minute hemorrhagic lesions.

30

What are the two virulence factors of neisseria meningitidis

the capsule and the endotoxin

31

how is neisseria meningitidis transmitted

aerosol droplets, close contact facilitates transmission
(carrier rate is higher in military personnel)

32

How is neisseria meningitidis diagnosed

symptoms, characteristics

33

How is neisseria meningitidis treated

i.v. penicillin or cephalosporin

34

What should high risk populations for neisseria meningitidis do

get the quadrivalent vaccine

35

What are enterobacteriaceae

a large family of gram-negative rods

36

What kinds of interaction do enterobacteriaceae have with oxygen

facultative aerobic

37

are enterobacteriaceae common commensals in humans

yes

38

what are the three types of surface antigens on enterobacteriaceae

O, K, and H

39

are enterobacteriaceae infections common nosocomial infections

yes

40

how well do disinfectants and antibiotics work against enterobacteriaceae

disinfectants easily kill them, antibiotics do not

41

What are the three types of enterobacteriaceae

1. coliforms - those that ferment glucose
2. noncoliforms - those that don't ferment glucose
3. Frank pathogens

42

What does the presence of coliforms in water indicative of

impure water, and poor sewage treatment

43

What is the most common and important of the enterobacteriaceae coliforms

Escherichia Coli (E. Coli)

44

What are the most common diseases associated with E. Coli

UTIs and Gastroenteritis

45

What is the most common cause of non-nocosomial UTIs

E. Coli

46

What are the two main virulence factors of E. Coli

pili and exotoxins

47

What are the 5 main different varieties of E.Coli

Uropathic E. Coli - more likely to produce UTI
Enterotoxogenic E. Coli - causes diarrhea
Enteropathogenic E. Coli - infant diarrhea
Enterohemorrhagic E. Coli - Hemolytic Uremic Syndrome
Enteroinvasive E. Coli - causes dysentary

48

Why is type 1 pili of E. Coli important

those E. Coli with type 1 Pili can hold on to the bladder and aren't flushed out, so they can cause a UTI. Those without it are flushed out and not pathogenic

49

what causes most E. Coli Epidemics

undercooked ground beef, unpasteurized milk or juice, or fresh vegetables

50

What is shigella

a gram-negative nonmotile bacteria that is a parasite of the human digestive system

51

what is the diseases associated with shigella, and what causes it

the disease is a bacillary dysentary called shigellosis, the diarrhea inducing enterotoxin is what causes it

52

shigella is spread by the 5 Fs, what are they

flies
fingers
fomites
food
feces

53

What is the shigella toxin similar to, and how

it is similar to the ricin toxin, it is similar because it is an AB toxin, it inactivates ribosomes, and causes apoptosis

54

What happens with shigella once it enters the cell

it is absorbed into a phagosome, which it escapes, then polymerizes actin into a tail and flies around the cell and into others

55

What does salmonella do once absorbed into marcophages

it multiplies in them and spreads

56

Where is salmonella found

in the intestines and feces of most birds, reptiles and mammals

57

What is the most common cause of salmonella infections for humans

food contaminated with animal feces

58

What are the two important pathogens of salmonella

Salmonella enterica serovar typhimurium
Salmonella enterica serovar typhi

59

what does Salmonella enterica serovar typhimurium cause

salmonellosis

60

what does Salmonella enterica serovar typhi cause

typhoid fever

61

Where can you find Salmonella enterica serovar typhi

only in humans

62

how do you get Salmonella enterica serovar typhi

ingestion of food or water that is in from sewage contaminated with the bacteria

63

What happens with Salmonella enterica serovar typhi once you ingest it

it goes from the intestines into the blood, to the liver, spleen, bone marrow, and gall bladder, then back into the intestines and all over again. can cause peritonitis

64

Who was typhoid mary

a cook with Salmonella enterica serovar typhi, that accidentally killed many families by feeding them contaminated food

65

How is typhoid fever treated

with antimicrobial drugs

66

how is typhoid fever prevented

temporary vaccines can be given to those traveling to areas where typhoid fever is endemic

67

how does salmonella get through the intestinal walls

it causes the M-cells to ruffle so it can go through

68

What is klebsiella

an opportunist with a capsule that protects it from phagocytosis

69

what is the most common pathogenic type of klebsiella

Klebsiella pneumoniaea

70

What does Klebsiella pneumoniaea cause

pneumonia, and maybe bacteremia, meningitis, wound infections, and UTIs

71

What is Yersina

a normal pathogen of animals that can be acquired via consumption of food or water contaminated with animal feces

72

What are the three important yersina species

Yersina enterolitica
Yersina pseudotuberculosis
Yersina pestis

73

What is caused by a Yersina entericolitica infection

inflammation of the intestinal tract (similar symptoms to appendicitis)

74

What is caused by Yersina Pseudotuberculosis

less severe inflammation of the intestinal tract than Yersina entericolitica

75

What is caused by Yersina Pestis

the bubonic plague
high fever, swollen painful lymph nodes (buboes)
pneumonic plague

76

How quickly does a respiratory infection of yersina pestis kill

2-4 days from exposure to death.

77

how quickly after symptoms begin does treatment have to be started to prevent death

treatment must be started within 24 hours of symptoms onset or fatality is near 100%

78

What are the virulence factors of yersina pestis

F1 capsule - antiphagocytotic
T3SS - delivers YOPS
YOPS - inhibit cytokines, destroy cytoskeleton, trigger apoptosis

79

What is bordetella

a small aerobic nonmotile coccobacillus

80

What is the most significant bordetella

bordetella pertussis

81

what does bordetella pertussis cause

pertussis ((whooping cough))

82

Who is most commonly infected with bordetella

children

83

what are the virulence factors of B. pertussis

Adhesons
Toxins

84

How is B. pertussis transmitted

inhaled in aerosols

85

What are the two pertussis adhesons

filamentous hemagluttinin and perussis toxin

86

What are the four B. Pertussis toxins

pertussis toxin
Adenylate cyclase toxin
dermonecrotic toxin
Tracheal cytotoxin

87

what does pertussis toxin cause

increased mucus production

88

what does adenylate cyclase toxin cause

increased mucus production and inhibition of leukocyte functions

89

what does dermonecrotic toxin cause

constriction and hemorrhage of blood vessels

90

what does tracheal cytotoxin cause

inhibits cilia movement and kills ciliated cells

91

Where can pseudonomads be found

water and plants

92

why are pseudonomads problematic in hospitals

because they can be found in numerous locations

93

what is the most common human pseudonomad pathogen

psuedomonas aeruginosa

94

Who is typically infected with pseudomonas aeruginosa

immunocompromised patients

95

What condition is often worsened by pseunomonas aeruginosa

cystic fibrosis, it increases the likelyhood of death in these patients

96

what does pseudomonas aeruginosa do to protect itself from phagocytes

forms a biofilm

97

What else is pseudomonas aeruginosa involved in

infections of severe burns
hot tubitis

98

What are some diagnostic characteristics of pseudomonas aeruginosa

pyocyanin - a blue-green pigment with a fruity odor
fluorescent pigment

99

how easily is pseudomonas aeruginosa treated

not easily, it is resistant to many antibacterial drugs

100

What is francisella tularensis

nonmotile strict aerobe found in animals, that causes tularemia

101

how is francisella tularensis trasmitted to humans

bite of an infected tick or deerfly, or contact with an infected animal

102

how infectious is francisella tularensis

very, less than 10 cells needed, and it can spread through unbroken skin and mucus membranes

103

Why is tularemia often misdiagnosed

its symptoms are common to other bacterial and viral diseases

104

What is different about the necessary conditions of legionella pneumophilia

it needs cysteine, iron and a lower pH (6.9) to grow

105

how do humans become infected with legionella pneumophilia

inhaling the bacteria in aerosols from various water sources

106

legionella are intracellular parasites

that is true

107

What causes legionaires disease (causes pneumonia)

legionella pneumophilia

108

how do you eliminate the legionella pneumophilia

you can't, but you can reduce their numbers to successfully control it

109

what kind of agar is legionella pneumophilia grown on

charcoal agar

110

how and where does legionalla pneumophilia multiply in humans

it multiplies in macrophages
1. it gets phagocytosed (OMP and Mip assist)
2. the phagosome is coated in ribosomes and mitochondria (don't let the phagosome fuse)
3. legionella multiplies inside the macrophage to very high numbers, then the release a pore forming toxin and lyse the cell, then spread.