Pathogenic Gram-Negative Cocci and Bacilli Flashcards
1
Q
______ is the only genus of Gram-negative cocci that regularly causes disease in humans
A
Neisseria
2
Q
What is the morphology for the genus Neisseria?
A
Diplococci
3
Q
______ refers to pairs of spherical-shaped cells
A
Cocci
4
Q
What is the function of fimbriae, polysaccharide capsules, and lipooligosaccharide (LOS) regarding the initiation of disease from Neisseria?
A
They enable bacteria to invade human cells
5
Q
Name the 2 species of pathogenic Neisseria and the diseases that they cause
A
- Gonococcus - gonorrhea
- Meningococcus - meningitis
6
Q
What is the origin of the word ‘gonorrhea’?
A
“flow of the seed”
7
Q
What mucous membrane system do gonococci adhere to via fimbriae and capsules?
A
GU tract lining
8
Q
Describe the effects of N. gonorrhoeae on men (3)
A
- Urethra infection
- Painful urination
- Pus-filled discharge
9
Q
Describe the effects of N. gonorrhoeae on women (2)
A
- Cervix / uterus infection
- Asymptomatic
10
Q
Pelvic inflammatory disease (PID) is a complication from gonorrhea in ______
A
Women
11
Q
What are the complications associated with PID? (3)
A
- Scarring of uterine tubes
- Ectopic pregnancies
- Sterility
12
Q
What 2 bodily fluids does Neisseria meningitidis invade in the case of life-threatening diseases?
A
- Blood
- Cerebrospinal fluid
13
Q
How is meningococcal meningitis transmitted?
A
Respiratory droplets
14
Q
What is the function of the polysaccharide capsule of N. meningititdis?
A
Resists lytic enzymes allowing meningococci to be carried throughout the body
15
Q
Why is meningococcal meningitis considered a medical emergency?
A
Causes death within 6 hours
16
Q
What is meningococcal septicemia?
A
Blood poisoning
17
Q
In meningococcal septicemia, what does lipooligosaccharide trigger? (2)
A
- Blood coagulation
- Petechiae
18
Q
What are petechiae?
A
Hemorrhagic skin lesions
19
Q
What are enteric bacteria?
A
Intestinal microbiota
20
Q
What are the 3 major groups of pathogenic enteric bacteria?
A
- Coliform opportunists
- Non-coliform opportunists
- True pathogens
21
Q
What are the 3 antigenic components of lipopolysaccharide (LPS)?
A
- Core polysaccharide
- O polysaccharide
- Lipid A
22
Q
Core polysaccharide is a common ______
A
Antigen
23
Q
Lipid A is ______
A
An endotoxin
24
Q
Serological identification of antigens allow distinguishing among …
A
Strains and species of enteric bacteria
25
A type III secretion system is a complex structure that inserts into the cytoplasmic membrane via a ______
Hypodermic needle
26
What is the function of a type III secretion system?
Introduces proteins into the host cell
27
What is the morphology of coliforms?
Rod-shaped
28
What is the function of coliforms?
Ferments lactose to form gas
29
Where are coliforms found? (4)
- Decaying vegetation
- Intestinal tracts
- Plants
- Soil
30
What do fecal coliforms in water indicate?
Impure water / poor sewage treatment
31
Of the opportunistic coliform pathogens, which species is the most common and important?
E. coli
32
Name 4 human diseases for which E. coli is responsible
- Septicemia
- UTIs
- Neonatal meningitis
- Gastroenteritis
33
E. coli is the most common cause of ______
UTIs
34
How is E. coli often introduced into the urethra?
Fecal contamination
35
Why are females more likely than males to acquire urinary tract infections (UTIs)?
Female urethras are shorter and closer to the anus
36
What is urethritis?
Inflammation of the urethra
37
What is the function of fimbriae in the development of bacterial urethritis?
They allow bacteria to adhere to epithelial cells
38
What is cystitis?
Inflammation of the bladder
39
What is pyelonephritis?
Inflammation of the kidneys
40
What is the function of flagella in the development of bacterial cystitis / pyelonephritis?
They propel bacteria up into the urethra
41
______ is the most common disease associated with E. coli
Gastroenteritis
42
What are the effects of enterotoxins on the GI tract? (4)
- Loss of sodium
- Loss of potassium
- Loss of bicarbonate
- Loss of water
43
What is the current most prevalent strain of pathogenic E. coli in developed countries?
E. coli O157:H7
44
Name 3 food sources associated with epidemics E. coli O157:H7
- Undercooked ground beef
- Unpasteurized milk
- Unpasteurized fruit juice
45
E. coli O157:H7 produces a ______
Type III secretion system
46
What are the functions of the proteins introduced into intestinal cells by E. coli O157:H7? (2)
- Disrupt cell metabolism
- Facilitate attachment of additional E. coli O157:H7
47
What effect does the Shiga-like toxin of E. coli O157:H7 have upon host cells?
Inhibits protein synthesis
48
What effect do antimicrobial drugs have upon Shiga-like toxin production in E. coli O157:H7?
Increase production of Shiga-like toxin
49
What are the 3 truly pathogenic, non-lactose-fermenting bacteria in the family Enterobacteriaceae?
- Salmonella
- Shigella
- Yersinia
50
Are Salmonella, Shigella, and Yersinia considered to be members of the normal microbiota of humans?
NO
51
Of Salmonella, Shigella, and Yersinia, which is the most common?
Salmonella
52
Where are Salmonella species commonly found?
Intestines of birds, reptiles, and mammals
53
What species of Salmonella includes more than 2000 unique strains?
S. enterica
54
What are some major sources of infection associated with salmonellae? (3)
- Food contaminated with animal feces
- Poultry
- Eggs
55
Salmonella is ______
Acid sensitive
56
Infections of salmonella with ______ cells are usually asymptomatic
Fewer than 1 million
57
What condition results with larger infective doses of S. enterica?
Salmonellosis
58
Where do S. enterica cells attach / reproduce, causing salmonellosis?
The small intestine
59
How do salmonellae cells induce host cells to endocytize them?
They use type III secretion systems to induce nonphagocytic cells
60
What effect do reproducing, intracellular salmonellae have upon host cell viability?
They kill host cells
61
When does bacteremia occur?
When salmonellosis strains enter the blood
62
Bacteremia causes ______ infections
Localized
63
What is the treatment for salmonellosis?
Fluid and electrolyte replacement
64
What human disease is caused specifically by Salmonella enterica serotype Typhi?
Typhoid fever
65
What causes S. enterica Typhi infection?
Ingestion of asymptomatic carriers
66
In S. enterica Typhi infections, bacteria are phagocytized but ...
NOT killed
67
Name 4 organ systems that harbor S. enterica Typhi cells after they have passed through the intestinal cells and into the bloodstream
- Liver
- Spleen
- Bone marrow
- Gallbladder
68
What is peritonitis?
Inflammation of the peritoneum
69
What causes peritonitis?
Bacteria perforate the intestinal wall and enter the abdominal cavity
70
What is the causative agent of shigellosis?
Shigella
71
Describe the stool associated with salmonella
Non-bloody diarrhea
72
Describe the stool associated with shigellosis
Bloody diarrhea
73
What kind of toxin produced by shigella is responsible the symptoms of shigellosis?
Diarrhea-inducing enterotoxin
74
What are the causes of Shigella? (3)
- Poor personal hygiene
- Ineffective sewage treatment
- Contaminated foods
75
Shigella is not affected by ______
Stomach acid
76
Where do the main events in shigellosis occur after Shigella cells colonize the small intestine?
The large intestine
77
Where does Shigella multiply within the GI tract?
Cytoplasm
78
Where does Salmonella multiply within the GI tract?
Endocytic vesicles
79
How do Shigella cells move between neighboring epithelial cells?
Uses actin fibers to push into adjacent cells
80
How do salmonellosis and shigellosis differ with respect to development of bacteremia?
Shigellosis rarely causes bacteremia
81
Which species of Shigella secretes an exotoxin called Shiga toxin?
Shigella dysenteriae
82
What is the treatment for shigellosis?
Fluid and electrolyte replacement
83
Is Yersinia pestis (an extremely virulent pathogen) an enteric bacterium or a nonenteric one?
Nonenteric
84
What are the 2 types of plague caused by Y. pestis?
- Bubonic plague
- Pneumonic plague
85
What are the mammalian hosts for the natural endemic cycle of Y. pestis? (3)
- Rats
- Mice
- Voles
86
Do the mammalian hosts for the natural endemic cycle of Y. pestis develop disease?
NO
87
What are the biological vectors for the spread of plague bacteria in mammalian hosts?
Fleas
88
What is the function of multiplying bacteria on a flea’s feeding?
They block the esophagus
89
What ways can humans become infected with bubonic plague? (2)
- Bites from infected fleas
- Direct contact with infected animals
90
What is the primary manifestation of bubonic plague?
Buboes
91
What are buboes?
Swollen, painful lymph nodes
92
What conditions result from untreated cases of bubonic plague? (3)
- DIC
- Subcutaneous hemorrhaging
- Tissue necrosis
93
______ is the common name for bubonic plague caused by Y. pestis, associated with death of affected tissues
Black death
94
When does pneumonic plague occur?
When Yersinia infects the lungs
95
How is pneumonic plague transmitted among human populations? (2)
- Aerosols
- Sputum
96
How is plague prevented? (2)
- Rodent control
- Personal hygiene
97
What is the causative agent of pertussis or ‘whooping cough’?
B. pertussis
98
How does B. pertussis cause disease?
It interferes with ciliated epithelial cells of the trachea
99
What effect does pertussis toxin have on ciliated epithelial cells?
Increases mucus production
100
What are the 4 stages of disease progression of pertussis?
- Incubation stage
- Catarrhal stage
- Paroxysmal stage
- Convalescent stage
101
Bacteria multiplying with no symptoms refers to the ______ stage of pertussis progression
Incubation
102
Signs and symptoms resembling a common cold refers to the ______ stage of pertussis progression
Catarrhal
103
Exhaustive coughing spells refers to the ______ stage of pertussis progression
Paroxysmal
104
Growth of ciliated lining and diminished coughing spells refers to the ______ stage of pertussis progression
Convalescent
105
What is the CDC recommendation regarding vaccination against pertussis?
Parents should immunize their children
106
Is P. aeruginosa a true pathogen or an opportunistic pathogen?
Opportunistic pathogen
107
Name 2 toxins produced by P. aeruginosa that inhibit protein synthesis
- Exotoxin A
- Exoenzyme S
108
What are the functions of elastase in P. aeruginosa infections? (2)
- Breaks down elastic fibers
- Cleaves IgA and IgG
109
What is the name of the blue-green pigment produced by P. aeruginosa?
Pyocyanin
110
Pyocyanin causes ______
Tissue damage
111
Describe the relationship between burn victims and P. aeruginosa infections
Burned areas provide a warm, moist, environment
112
⅔ of burn victims develop environmental / nosocomial ______ infections
Pseudomonas
