Infectious Disease - Details not in Sketchy Bacteria Flashcards
1
Q
There are about 15 Staphylococcal species that cause disease in humans. Which are most important to know?
A
- S. aureus*
- S. epidermidis*
- S. saprophyticus*
2
Q
Besides cluster pattern on plating, what test can be used to differentiate between Staphylococci and Streptococci?
A
Catalase test
(Staphylococci are catalase-positive)
3
Q
What does coagulase do?
What Staphylococcal species produce it?
A
Cleaves fibrinogen to fibrin;
S. aureus, S. argentus (rare)
4
Q
How does the exfoliative toxin produced by S. aureus cause scalded skin syndrome?
A
It targets desmoglein I
(both SSS and the autoimmune disease pemphigus vulgaris target desmosomes)
5
Q
Rapid-onset food poisoning caused by S. aureus will resolve when what happens?
A
The enterotoxinsareeliminated from the body
6
Q
Superantigens cross-links ___ cells indiscriminately (can activate up to ___%!) and leads to massive ________ ________.
A
Superantigen cross-links T cells indiscriminately (can activate up to 50%) and leads to massive cytokine storms.
7
Q
Superantigens cross-link what?
A
TCRs and MHC II
(indiscriminate T cell activation)
8
Q
True/False.
Only a fraction of S. aureus strains produce enterotoxins or TSSTs or exfoliative toxins.
A
True.
9
Q
Why does scalded skin syndrome typically only happen in children?
A
Less desmoglein I in adults
10
Q
How do bacteria burrow through tissues?
A
Lytic enzymes
(e.g. collagenases; hyaluronases; etc.)
11
Q
What bacterial species have Protein A?
A
S. aureus only
12
Q
How does S. aureus adhere to mucosal surfaces?
A
Fibronectin-binding protein
13
Q
All S. aureus species produce an ______-toxin that lyse human cells.
A
All S. aureus species produce an α-toxin that lyse human cells.
14
Q
Which Staphylococci produce toxins?
A
S. aureus only
15
Q
S. saprophyticus is normal flora where?
A
The perineum;
the female genital tract
16
Q
S. saprophyticus is the ____ most common cause of UTIs and cystitis in young women (after E. coli).
A
S. saprophyticus is the 2nd most common cause of UTIs and cystitis in young women (after E. coli).
17
Q
Why does S. saprophyticus need urease?
A
To survive in urine
18
Q
Can S. saprophyticus produce biofilms?
A
Yes.
19
Q
Where does our microbiota come from?
A
Breathing, birth canal, touching, eating
20
Q
True/False.
Lactobacilli, coliforms, and anaerobes are part of the microbiota.
A
True.
Lactobacilli, coliforms, and anaerobes are part of the microbiota.
21
Q
You determine that a gram-positive coccus is catalase-negative. What can you test next to determine narrow down the species?
A
The hemolysis pattern
22
Q
Describe the differences between α-, β-, and γ-hemolysis.
A
α-hemolysis (Hgb oxidized to methemoglobin) (greenish-brownish)
β-hemolysis (the bacteria produces hemolysins) (clear, yellow)
γ-hemolysis (no hemolysis) (whiteish)
23
Q
Identify which respective square represents each of the following:
β-hemolysis
α-hemolysis
γ-hemolysis
A
β-hemolysis (the bacteria produces hemolysins) (clear, yellow) – Lower right
α-hemolysis (hemoglobin oxidized to methemoglobin) (greenish-brownish) – Lower left
γ-hemolysis (no hemolysis) (whiteish) – Upper right and left
24
Q
Name the relevant bacteria species classified as each of the following:
Group A strep.
Group B strep.
Group D strep.
Non-groupable
Viridans
A
Group A strep. — S. pyogenes
Group B strep. — S. agalactiae
Group D strep. — S. bovis
Non-groupable strep. — S. pneumoniae
Viridans strep. — S. mutans, S. sanguinis
25
What term describes catarrhal inflammation of the mucous membrane in the nose, caused especially by a cold or by hay fever.
Coryza
26
The roles of *S. pyogenes* M protein are to mediate ___________ and \_\_\_\_\_\_\_\_\_\_\_. It also has anti-\_\_\_\_\_\_\_\_\_\_ activity and degrades \_\_\_\_\_.
Where is it found?
The roles of *S. pyogenes* M protein are to mediate **adherence** and **internalization**. It also has anti-**phagocytic** activity and degrades **C3b**;
bound to the bacterial **cell** **membrane**
27
Besides degrading C3b, *S. pyogenes* also secretes a peptidase that degrades what other complement factor?
C5a
28
*S. pyogenes* secretes streptolysin ____ and \_\_\_\_.
*S. pyogenes* secretes streptolysin **O** and **S**.
29
C. Acute rheumatic fever
30
Some *S. pyogenes* M proteins are similar in structure to proteins found on \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.
Some *S. pyogenes* M proteins are similar in structure to proteins found on **_cardiomyocytes_**.
31
Rheumatic fever is a type ____ hypersensitivity reaction.
Poststreptococcal glomerulonephritis is a type ____ hypersensitivity reaction.
Rheumatic fever is a type **_II_** hypersensitivity reaction.
Poststreptococcal glomerulonephritis is a type **_III_** hypersensitivity reaction.
32
Poststreptococcal glomerulonephritis typically occurs ~\_\_\_ _______ after original strep. infection.
Poststreptococcal glomerulonephritis typically occurs ~_**2** **weeks**_ after original strep. infection.
33
Scarlet fever typically follows streptococcal ___________ and is mediated by ___________ toxin that is activated by **lysogenic** conversion via a **bacteriophage**.
Scarlet fever typically follows streptococcal **_pharyngitis_** and is mediated by **_erythrogenic_** toxin that is activated by **lysogenic** conversion via a **bacteriophage**.
34
Scarlet fever typically follows streptococcal **pharyngitis** and is mediated by **erythrogenic** toxin that is activated by __________ conversion via a \_\_\_\_\_\_\_\_\_\_.
Scarlet fever typically follows streptococcal **pharyngitis** and is mediated by **erythrogenic** toxin that is activated by **_lysogenic_** conversion via a **_bacteriophage_**.
35
The human body does not typically mount immune responses against the *S. agalactiae* capsule because they are composed of _____ \_\_\_\_\_ (which is not immunogenic as it is naturally occurring in the body).
The human body does not typically mount immune responses against the *S. agalactiae* capsule because they are composed of **_sialic acid_** (which is not immunogenic as it is naturally occurring in the body).
36
*S. agalactiae* can be either β-hemolytic or \_\_\_-hemolytic (but is usually β-hemolytic).
*S. agalactiae* can be either β-hemolytic or **γ**-hemolytic (but is usually β-hemolytic).
37
*S. pneumoniae* utilizes \_\_\_\_\_\_\_\_\_\_\_\_. It is a pore-forming toxin that lyses ________ and ________ and also activates **complement**. It is not **secreted**; it is only released upon **auto**-**lysis**.
*S. pneumoniae* utilizes **_pneumolysin_**. It is a pore-forming toxin that lyses **_RBCs_** and **_platelets_** and also activates **complement**. It is not **secreted**; it is only released upon **auto**-**lysis**.
38
*S. pneumoniae* utilizes \_\_\_\_\_\_\_\_\_\_\_. It is a pore-forming toxin that lyses **RBCs** and **platelets** and also activates **complement**. It is not \_\_\_\_\_\_\_\_\_; it is only released upon \_\_\_\_\_-\_\_\_\_\_.
*S. pneumoniae* utilizes **_pneumolysin_**. It is a pore-forming toxin that lyses **RBCs** and **platelets** and also activates **complement**. It is not **_secreted_**; it is only released upon **_auto_**-**_lysis_**.
39
The most important virulence factors for *S.* *pneumoniae* infection are their polysaccharide _________ (which are immunogenic and anti-**_phagocytic_**).
The most important virulence factors for *S.* *pneumoniae* infection are their polysaccharide **_capsules_** (which are immunogenic and anti-**_phagocytic_**).
40
**True/False**.
Alcohol use disorder increases the risk of *S. pneumoniae* infection.
True.
41
*S. pneumoniae* can be identified by the __________ reaction (methylene blue indicates presence of a \_\_\_\_\_\_\_\_\_\_).
*S. pneumoniae* can be identified by the **_Quelling_** reaction (methylene blue indicates presence of a **_capsule_**).
42
How does *S. pneumoniae* inhibit C3b activity?
The capsule **_binds Factor H_**
43
\_\_\_\_\_\_\_\_\_\_\_\_ bacteria have extra protection against immune/leukocyte responses and are much more likely to have the time to cross the blood-brain barrier and cause meningitis.
**_Encapsulated_** bacteria have extra protection against immune/leukocyte responses and are much more likely to have the time to cross the blood-brain barrier and cause meningitis.
44
What makes the capsule around *B. anthracis* unique?
It is a polypeptide
| (D-glutamate)
45
What is an eschar?
A cutaneous lesion with central necrosis
46
What are the three general types of infection caused by *B. anthracis*?
Cutaneous, pulmonary, GI
47
How *B. anthracis* colonies appear when plated?
**γ**-**hemolytic**;
sticky, ‘medusa head’ forms on agar
48
What does it mean if an organism is saprophytic?
It grows out of decaying organic matter
49
What does it mean if an organism is fastidious?
It only grows when very specific nutrients are included in its medium
50
Identify which of the following are catalase-positive:
## Footnote
* Staphylococci*
* Streptococci*
* Enterococci*
* Bacilli*
* Cornyebacteria*
***Staphylococci***
***Bacilli***
51
Describe the difference in ingestion of *B. cereus* toxins or spores.
Ingestion of toxin-containing foods: heat-\_\_\_\_\_\_ enterotoxin (cereulide) --\> rapid-onset ______ (\<6 hours).
Ingestion of spores (activation in gut): heat-\_\_\_\_\_ enterotoxin --\> slow-onset ______ (\>6 hours).
Ingestion of toxin-containing foods: heat-**_stable_** enterotoxin (cereulide) --\> rapid-onset **_emesis_** (\<6 hours).
Ingestion of spores (activation in gut): heat-**_labile_** enterotoxin --\> slow-onset **_watery_** **_diarrhea_** (\>6 hours).
52
* Bacilli* are _______ \_\_\_robes.
* Clostridia* are _______ \_\_\_robes.
* Bacilli* are **_obligate_** **_ae_**robes.
* Clostridia* are **_obligate**_ _**anae_**robes.
53
Name the following toxins of *C. perfringens*:
\_\_\_-toxin – pore-forming toxin
\_\_\_-toxin (aka lecithinase or phospholipase)
**σ**-toxin – pore-forming toxin
**α**-toxin (aka lecithinase or phospholipase)
54
What bacteria results in this hemolysis pattern?
Which toxin causes the interior and which toxin causes the exterior?
*C. perfringens*;
Interior: **σ-toxin**
Exterior: **α-toxin**
55
Describe the *C. perfringens* hemolysis pattern.
Double zone of hemolysis
56
What test can be used to identify *C. perfringens* due to its phospholipase activity?
What toxin is it showing?
The **Nagler** reaction;
**α**-toxin
60
Why is hyperbaric O2 useful in treating cases of *C. perfringens* infection?
It is an obligate anaerobe
61
Which Gram-positive bacteria are a small part of the normal gut flora?
*C. difficile*
62
What are four gram-positive rods that are NOT spore-forming?
* C. diphtheriae*, *L. monocytogenes*;
* A. israelii*; *N. asteroides*
63
Why is *C. tetani* infection more likely in geriatric patients?
Waxing immunity to toxin
| (toxoid vaccine wears off)
64
What is the usual cause of death in patients with untreated *C. tetani* infection?
Suffocation
(respiratory muscles continually tensed/exhausted)
65
Identify which of the following are part of the normal body flora:
## Footnote
***Salmonella enteridis***
***E. coli***
***Shigella dysenteriae***
***Yersinia* *pestis***
***P. mirabilis***
***K. pneumoniae***
## Footnote
***E. coli***
***P. mirabilis***
***K. pneumoniae***
66
**True/False**.
All *Enterobacteriaceae* are bile-sensitive and oxidase-positive.
**False**.
All *Enterobacteriaceae* are bile-***resistant*** and oxidase-***negative***.
67
Identify which of the following are part of the *Enterobacteriaceae* class:
* H. pylori*
* C. diphtheriae*
* E. coli*
* Y. pestis*
* S. dysenteriae*
* P. aeruginosa*
* C. jejuni*
* V. cholerae*
* S. typhi*
## Footnote
***E. coli***
***S. tyhpi***
***Y. pestis***
68
What are two key factors that help differentiate *Enterobacteriaceae* from one another?
Motility;
H2S production
69
\_\_\_\_\_\_\_\_\_ ________ agar is used to select for Gram-negative H2S-producing organisms.
This is especially important in differentiating ***Salmonella*** and ***Shigella***.
**Hektoen** **enteric** agar is used to select for Gram-negative H2S-producing organisms.
This is especially important in differentiating ***Salmonella*** and ***Shigella***.
70
**Hektoen** **enteric** agar is used to select for Gram-negative H2S-producing organisms.
This is especially important in differentiating *\_\_\_\_\_\_\_\_\_* and *\_\_\_\_\_\_\_\_\_*.
**Hektoen** **enteric** agar is used to select for Gram-negative H2S-producing organisms.
This is especially important in differentiating ***_Salmonella_*** and ***_Shigella_***.
71
On Hektoen enteric agar, ***Salmonella*** produces _______ colonies and ***Shigella*** produces _______ colonies.
On Hektoen enteric agar, ***Salmonella*** produces **_black_** colonies and ***Shigella*** produces **_green_** colonies.
72
On Hektoen enteric agar, __________ produces **black** colonies and \_\_\_\_\_\_\_\_\_\_ produces **green** colonies.
On Hektoen enteric agar, ***_Salmonella_*** produces **black** colonies and ***_Shigella_*** produces **green** colonies.
73
Identify which of the following can ferment lactose:
## Footnote
***E. coli***
***Enterobacter spp.***
***Salmonella spp.***
***P. mirabilis***
## Footnote
***E. coli***
***Enterobacter spp.***
74
What is indicated by the 'O' and 'H' in O157:H7 *E. coli*?
Types of O antigen and H antigen
75
**True/False**.
All *Enterobacteriaceae* have endotoxins and produce exotoxins.
**True**.
76
Most *E. coli* is flushed from the bladder/urethra via normal voiding because there are no type ___ pili receptors in the bladder.
*E. coli* can stick in the bladder if they have the \_\_-pili as well as type 1 pili.
Most *E. coli* is flushed from the bladder/urethra via normal voiding because there are no type **_1_** pili receptors in the bladder.
*E. coli* can stick in the bladder if they have the **_P_**-pili as well as type 1 pili.
78
*Citrobacter* are lactose-fermenting bacteria similar to *\_\_\_\_\_\_\_\_\_\_* that are biochemically and serologically similar to *\_\_\_\_\_\_\_\_\_\_*.
*Citrobacter* are lactose-fermenting bacteria similar to ***Enterobacter*** that are biochemically and serologically similar to ***Salmonella***.
79
* Shigella* ______ (are/are not) H2S-producing.
* Shigella* ______ (are/are not) motile.
* Shigella* **are not** H2S-producing (green colonies on Hektoen enteric agar).
* Shigella* **are not** motile.
80
Name a few species of *Shigella spp.*
Which one produces Shiga toxin and the most severe disease?
***S. dysenteriae***,
* S. sonnei*,
* S. flexneri*,
* S. boydii*
81
* Salmonella* ______ (are/are not) H2S-producing.
* Salmonella* ______ (are/are not) motile.
* Salmonella* **are** H2S-producing (black colonies on Hektoen enteric agar).
* Salmonella* **are** motile.
82
\_\_\_\_\_\_\_\_\_ (*Shigella/Salmonella*) **are** H2S-producing (black colonies on Hektoen enteric agar).
\_\_\_\_\_\_\_\_\_ (*Shigella/Salmonella*) **are not** motile.
***_Salmonella_*** **are** H2S-producing (black colonies on Hektoen enteric agar).
***_Shigella_*** **are not** motile.
83
Describe the difference between how enteropathogenic, enterotoxigenic, and enterohemorrhagic *E. coli* interact with human enterocytes.
84
Describe the difference between how enteroaggregative, enteroinvasive, and uropathogenic *E. coli* interact with human enterocytes.
85
Describe the different types of *E. coli* as shown in the attached image.
86
B. *P. mirabilis*
(Note: urease-producing; lactose-negative; swarming motility in right image)
87
Name a few Gram-negative, oxidase-positive, motile rods.
* Campylobacter jejuni.*,
* Pseudomonas aeruginosa*,
* Helicobacter* *pylori*,
* Vibrio cholerae*
88
Which of the following are oxidase-positive?
***Campylobacter jejuni***
***Pseudomonas aeruginosa***
***Helicobacter pylori***
***Vibrio cholerae***
## Footnote
***Campylobacter jejuni***
***Pseudomonas aeruginosa***
***Helicobacter pylori***
***Vibrio cholerae***
89
Which of the following are motile?
## Footnote
***Campylobacter jejuni***
***Pseudomonas aeruginosa***
***Helicobacter pylori***
***Vibrio cholerae***
## Footnote
***Campylobacter jejuni***
***Pseudomonas aeruginosa***
***Helicobacter pylori***
***Vibrio cholerae***
90
D. *Pseudomonas aeruginosa*
91
**True/False**.
*Pseudomonas aeruginosa* is rare but can be found sometimes in water.
**False**.
*Pseudomonas aeruginosa* is ***ubiquitous*** and is often found in soil, vegetation, water, moist reservoirs, etc.
92
How are *Pseudomonas aeruginosa* flagella oriented?
Polar flagella
93
*Pseudomonas aeruginosa* produces a blue-green pigmentation (via pyocyanin and pyoveridin) that can be seen on _______ and in \_\_\_\_\_\_\_.
*Pseudomonas aeruginosa* produces a blue-green pigmentation (via pyocyanin and pyoveridin) that can be seen on **_agar_** and in **_wounds_**.
94
How common is *Pseudomonas aeruginosa* in hospital settings?
95
*Pseudomonas aeruginosa* are able to adhere well to mucosal surfaces via _______ and \_\_\_\_\_\_\_.
*Pseudomonas aeruginosa* are able to adhere well to mucosal surfaces via **_pili_** and **_biofilms_**.
96
With what form of hemolysis does *Pseudomonas aeruginosa* present on agar?
**β-hemolysis**
97
*Burkholderia cepacia* are 17 different species that cause \_\_\_\_\_\_\_\_\_\_\_, \_\_\_\_\_\_\_\_\_\_\_, and ___________ infections.
These infections are more common in **CF**, **immunocompromised**, **chronic granulomatous disease patients**, and **neonates**.
*Burkholderia cepacia* are 17 different species that cause **_septicemia_**, **_respiratory_**, and **_urinary tract_** infections.
These infections are more common in **CF patients**, **immunocompromised**, **chronic granulomatous disease patients**, and **neonates**.
98
*Burkholderia cepacia* are 17 different species that cause **septicemia**, **respiratory**, and **urinary tract** infections.
These infections are more common in _______ patients, _________ patients, __________________ patients, and \_\_\_\_\_\_\_\_\_.
*Burkholderia cepacia* are 17 different species that cause **septicemia**, **respiratory**, and **urinary tract** infections.
These infections are more common in **_CF patients_**, **_immunocompromised patients_**, **_chronic granulomatous disease patients_**, and **_neonates_**.
99
*\_\_\_\_\_\_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_\_\_\_* are 17 different species that cause septicemia, respiratory, and urinary tract infections.
These infections are more common in CF patients, immunocompromised patients, chronic granulomatous disease patients, and neonates.
***_Burkholderia cepacia_*** are 17 different species that cause septicemia, respiratory, and urinary tract infections.
These infections are more common in _CF patients_, _immunocompromised patients_, _chronic granulomatous disease patients_, and _neonates_.
100
*V. cholerae* is a \_\_\_\_\_-volume, watery diarrhea.
The rice water stools are caused by little pieces of _______ in stool.
*V. cholerae* is a **_high_**-volume, watery diarrhea. (Fluid lost is often measured in liters.)
The rice water stools are caused by little pieces of **_biofilm_** in stool.
101
*V. cholerae* is halophilic. What does this mean?
What is the typical cause of death in patients with cholera?
How is cholera treated?
*V. cholerae* is salt-requiring;
dehydration;
ORS
102
C. *Vibrio vulnificus*
(flesh-eating bacteria associated with salt water with very rapid progression)
103
1. *Campylobacter*
104
Name a disease that can cause flesh-eating infection that is often associated with exposure to salt water and seafood (with very rapid progression to death).
*Vibrio vulnificus*
105
Name a species of the *Vibrio* family that causes a food-borne gastroenteritis with a 2% mortality rate (or wound infection with a 25% mortality rate). There are ~45,000 U.S. cases per year.
Name a species of the *Vibrio* family with a 50% mortality rate (100% if antibiotics are not started within 72 hours of illness onset) that is associated with contact with salt water. There are ~100 U.S. cases per year.
* Vibrio parahaemolyticus*
* Vibrio vulnificus*
106
# Describe the infections, incidence rates, and mortality rates for the following bacteria.
* Vibrio parahaemolyticus*
* Vibrio vulnificus*
A food-borne **gastroenteritis** (86% of cases) with a **2% mortality** rate (or wound infection with a 25% mortality rate).
There are **~45,000** U.S. cases per year.
A **50% mortality rate** (100% if antibiotics are not started within 72 hours of illness onset) that is associated with **contact with salt water**.
There are **~100** U.S. cases per year.
107
*Vibrio vulnificus* is especially likely to cause septicemia in patients with underlying medical conditions, especially ________ disease.
*Vibrio vulnificus* is especially likely to cause septicemia in patients with underlying medical conditions, especially **_liver_** disease.
108
Name three members of the *Vibrio* family.
***Vibrio cholerae*** (causes cholera)
***Vibrio parahaemolyticus*** (fairly common cause of vibriosis)
***Vibrio vulnificus*** (deadly cause of vibriosis)
109
*Campylobacter jejuni* is a fastidious organism that requires very selective media and growth conditions. It has to be incubated at ___ C, under micro\_\_\_\_\_\_\_\_\_ conditions.
*Campylobacter jejuni* is a fastidious organism that requires very selective media and growth conditions. It has to be incubated at **42°C**, under micro**aerophilic** conditions.
110
It is significant that *Campylobacter jejuni* must be cultured at 42°C as that is the natural temperature of \_\_\_\_\_\_\_\_, a commonly colonized carrier of *C. jejuni*.
It is significant that *Campylobacter jejuni* must be cultured at 42°C as that is the natural temperature of **_birds_**, a commonly colonized carrier of *C. jejuni*.
111
*Campylobacter jejuni* are very, very ________ in gut epithelia, thus explaining why infection often causes bloody diarrhea.
*Campylobacter jejuni* are very, very **_invasive_** in gut epithelia, thus explaining why infection often causes bloody diarrhea.
112
How long does infection with *Campylobacter jejuni* typically last without treatment?
And with treatment?
1 - 3 weeks;
\<3 days
113
What does the CDC estimate is the most common cause of bacterial diarrhea in the U.S.?
*C. jejuni*
114
\_\_\_ / 1000 cases of *C. jejuni* result in Guillan-Barre syndrome, usually ocurring ~\_\_\_ weeks after infection.
**_1_** / 1000 cases of *C. jejuni* result in Guillan-Barre syndrome, usually ocurring ~**_2_** weeks after infection.
115
~\_\_\_% of the world is colonized by *H. pylori* (~\_\_\_% are asymptomatic).
~**_50_**% of the world is colonized by *H. pylori* (~**_90_**% are asymptomatic).
116
An individual presenting with duodenal ulcers is asked to drink a solution containing radiolabeled urea. If the individual has an overgrowth of *H. pylori*, what do you expect to occur?
Exhaled radiolabeled CO2
117
What is the general source of most *Pseudomonas* infections?
What is the general source of most *Campylobacter* infections?
What is the general source of most *Helicobacter* infections?
What is the general source of most *Vibrio* infections?
Ubiquitous in moist reservoirs;
contaminated poultry (or other animals);
fecal-oral;
contaminated water, shellfish
118
*N**.** meningitidis*
119
The petechiae seen in *N. meningitidis* are caused by membrane shedding of \_\_\_\_\_\_\_.
*N. meningitidis* _______ (are/are not) motile.
What does *N. meningitidis* use to sequester iron?
The petechiae seen in *N. meningitidis* are caused by membrane shedding of **_Lipid A_**.
*N. meningitidis* **_are not_** motile.
What does *N. meningitidis* use to sequester iron? **_Siderophores_**
120
*N. gonorrheae* ______ (are/are not) motile.
*N. gonorrheae* **_are not_** motile.
121
**True/False**.
Lipopolysaccharide (LPS) is a major virulence factor for both *N. meningitidis* and *H. influenzae*.
**False**.
Lipo***oligo***saccharide (**LOS**) is a major virulence factor for both *N. meningitidis* and *H. influenzae*.
122
In what age range do most meningitis cases caused by *N. meningitidis* meningitis occur?
**Childhood**
(also a small bump in cases around age 20)
123
Why don't we produce a vaccine against type B *N. meningitidis*?
Type B capsule has **_sialic acid_**
(we don’t want to increase the likelihood of autoimmunity)
124
*B. pertussis*
125
*Bortadella pertussis* are:
oxidase-\_\_\_\_\_\_\_\_\_\_
\_\_\_\_\_\_capsulated
very _______ diplococci/coccobacilli
*Bortadella pertussis* are:
oxidase-**_positive_**
**_en_**capsulated
very **_small_** diplococci/coccobacilli
126
Why is completely eliminating *B. pertussis* very possible?
It is a **_strictly human pathogen_**
(could be eliminated through vaccinations)
127
What agar is necessary for *B. pertussis* to grow?
**Bordet-Gengou** agar
(agar treated with nicotinamide and charcoal)
128
*L. pneumophila*
(high fever + pneumonia + diarrhea + absent organisms)
129
**True/False**.
*L. pneumophila* stains poorly with Gram stain
True.
130
*L. pneumophila* are facultatively intracellular within ____________ (normally reside within environmental amoebas).
They are typically found in watery or moist environments due to their ability to form what?
*L. pneumophila* are facultatively intracellular within **_macrophages_** (normally reside within environmental amoebas).
**_Biofilms_**
131
B. *Haemophilus influenzae type B*
132
*H. influenzae* requires V-factor and X-factor.
What is V-factor?
What is X-factor?
Both of these are found in what agar?
NAD
hematin
chocolate agar
133
B. (often transmitted by birds --- only the turkey farm is useful information here. All the other S/Sy are farily non-specific.)
134
As *C. trachomatis* cannot produce muramic acid, it also cannot produce \_\_\_\_\_\_\_\_\_\_, of which muramic acid is a component.
As *C. trachomatis* cannot produce muramic acid, it also cannot produce **_peptidoglycan_**, of which muramic acid is a component.
135
*C. trachomatis* is an obligate intracellular energy parasite that has a strong ability to infect cells at the ____________ \_\_\_\_\_\_\_\_.
*C. trachomatis* is an obligate intracellular energy parasite that has a strong ability to infect cells at the **_squamocolumnar_** **_junction_**.
136
*C. trachomatis* is cultured in _______ cells with _______ stain used to illustrate the inclusions.
*C. trachomatis* is cultured in **_McCoy_** cells with **_iodine_** stain used to illustrate the inclusions.
137
Why is Listeriosis more common in pregnant women?
Due to decreased cell-mediated immune activity
(because of increased estrogen / progesterone)
138
Why doesn't Listeriosis need a capsule to cause meningitis?
It's an intracellular pathogen
139
*L. monocytogenes* are Gram-\_\_\_\_\_\_\_\_\_, \_\_\_\_\_\_capsulated, facultative intracellular ________ (shape).
*L. monocytogenes* are Gram-**_positive_**, **_unen_**capsulated, facultative intracellular **_coccobacilli_**.
140
What membrane-damaging toxin does *L. monocytogenes* produce?
Listeriolysin O
141
Name three bacterial families that all form actin rockets for transport.
* Listeria spp.*
* Shigella spp.*
* Rickettsia spp.*
142
What are the three genuses within the *Ricketsiae* family?
* Rickettsia*
* Coxiella*
* Ehrlichia*
143
How are most genuses within the *Ricketsiae* (*Rickettsia*, *Coxiella*, *Ehrlichia*) family transmitted?
Do the infections arise rapidly or slowly?
Arthropods;
rapidly
144
*Rickettsia ricketsii* adhere to and have a predilection for what cell type?
What is the result?
Endothelial cells;
vasculitis
145
Why might a Rickettsial infection present with negative serological tests and blood cultures?
They are **obligate intracellular** organisms
146
* Rickettsia prowazekii* typically causes a centri\_\_\_\_\_ rash.
* Rickettsia rickettsii* typically causes a centri\_\_\_\_\_ rash.
* Rickettsia prowazekii* typically causes a centri**_fugal_** rash (trunk to extremities).
* Rickettsia rickettsii* typically causes a centri**_petal_** rash (extremities to trunk).
147
Where is *Rickettsia rickettsii* infection (and RMSF) most common?
148
* Rickettsia* ____________ can cause Rocky Mountain spotted fever (RMSF).
* Rickettsia* ____________ can cause epidemic typhus.
* Rickettsia* ***_rickettsii_*** can cause Rocky Mountain spotted fever (RMSF).
* Rickettsia* ***_prowazekii_*** can cause epidemic typhus.
149
The rash associated with epidemic typhus (*Rickettsia prowazekii*) characteristically avoids what part(s) of the body?
The palms and soles
150
Brill-Zinsser disease manifests years after infection with what organism?
*Rickettsia prowazekii*
151
**True/False**.
Treatment for RMSF or typhus should be started on clinical suspicion _alone_ (don’t wait for confirmatory labs).
True.
152
* R. typhi* (the cause of endemic typhus) is transmitted to humans via what arthropod?
* R. prowazekii* (the cause of epidemic typhus) is transmitted to humans via what arthropod?
* R. ricketsii* (the cause of RMSF) is transmitted to humans via what arthropod?
Flea;
louse;
Dermacentor tick
153
A. Ehrlichiosis
154
***Ehrlichia*** and ***anaplasma*** are both characterized by:
Invasion/destruction of __________ / \_\_\_\_\_\_\_\_\_\_
Being \_\_\_\_\_\_-borne
Obligate intracellular organisms
A _________ lifecycle (like *Chlamydia* and *Coxiella*)
A similar presentation to _______ but without the rash
***Ehrlichia*** and ***anaplasma*** are both characterized by:
Invasion/destruction of **_monocyes_** / **_macrophages_**
Being **_tick_**-borne
Obligate intracellular organisms
A **_biphasic_** lifecycle (like *Chlamydia* and *Coxiella*)
A similar presentation to **_RMSF_** but without the rash
155
\_\_\_\_\_\_\_\_\_\_ and __________ are both characterized by:
Invasion/destruction of **monocyes** / **macrophages**
Being **tick**-borne
Obligate intracellular organisms
A **biphasic** lifecycle (like Chlamydia and Coxiella)
A similar presentation to **RMSF** but without the rash
***_Ehrlichia_*** and ***_anaplasma_*** are both characterized by:
Invasion/destruction of **monocyes** / **macrophages**
Being **tick**-borne
Obligate intracellular organisms
A **biphasic** lifecycle (like Chlamydia and Coxiella)
A similar presentation to **RMSF** but without the rash
156
Cat scratch fever (*B. henselae*)
157
Describe the lifecycle of *Bartonella henselae* between its arthropod host and infected humans.
158
All zoonotic infections have vectors except \_\_\_\_\_\_\_\_.
All zoonotic diseases have vectors except ***_Coxiella_***.
159
All zoonotic diseases are obligate intracellular except \_\_\_\_\_\_\_\_\_\_\_.
All zoonotic diseases are obligate intracellular except ***_Bartonella_***.
160
*Actinomyces israelii*
161
What is the likely diagnosis?
*Nocardia asteroides*
162
*Nocardia asteroids*:
Typically causes ________ infection in immunocompromised patients
Acid-fast + produces _________ lung lesions similar to TB
May cause cutaneous lesions follow minor \_\_\_\_\_\_
*Nocardia asteroids*:
Typically causes **_pulmonary_** infection in immunocompromised patients
Acid-fast + produces **_pulmonary_** lung lesions similar to TB
May cause cutaneous lesions follow minor **_trauma_**
163
Name an abcess-forming filamentous Gram-positive rod besides *Nocardia asteroides*.
*Nocardia brasiliensis*
164
A homeless man presents with bacillary angiomatosis and chronic lymphadenopathy. He reports having felt feverish most of last week. He is hospitalized for other reasons and is noticed over the next two weeks to have a fever that lasts about 5 days at a time before remitting and then relapsing.
What is the likely diagnosis?
*Bartonella quintana*
| ('trench fever')
165
**True/False**.
Tularemia is a fairly common endemic infection and is most often seen in children playing with rabbits purchased at pet shops.
**False**.
Tularemia is a fairly ***rare*** endemic infection and is most often seen in ***hunters, gardeners, and veterinarians.***
166
D. *Bacteriodes fragilis* --- gram-negative rod (Normally found in gut; anaerobic but aerotolerant; abcess former)
167
Bacteriodes are gram-\_\_\_\_\_\_\_\_ rods that are:
normally found in the \_\_\_\_,
\_\_\_robic but \_\_\_\_tolerant,
\_\_\_\_\_\_\_ formers.
Bacteriodes are gram-**negative** rods that are:
normally found in the **gut**,
**anae**robic but **aero**tolerant,
**abcess** formers.
168
What is the most commonly isolated gram-negative anaerobic rod in peritoneal infections (e.g. ruptured appendix)?
*Bacteroides fragilis*
169
What in this history might steer you towards a diagnosis of *Mycoplasma* infection?
Dry cough,
no bacteria on Gram stain,
X-ray more severe than presentation,
slow onset,
Summer instead of Winter,
high fever
170
*Mycoplasma* lacks a _____ \_\_\_\_\_ and so is resistant to antibiotics that target _____ \_\_\_\_\_s.
*Mycoplasma* lacks a **cell wall** and so is resistant to antibiotics that target **cell wall**s.
171
Identify any of the following that *Mycoplasma* has:
## Footnote
**Cell wall**
**Peptidoglycan**
**LPS**
None of these
172
*Mycoplasma* uses a __________ organelle to attach to _____ acid on pulmonary cells. It then burrows where?
*Mycoplasma* uses a **P1 adhesion** organelle to attach to **sialic** acid on pulmonary cells.
The **inter**cellular space (burrowing between cells)
173
*Mycoplasma* and *Ureaplasma* are both types of \_\_\_\_\_\_\_\_\_\_, meaning they are tiny and have no cell wall.
*Mycoplasma* and *Ureaplasma* are both types of **_mollicutes_**, meaning they are tiny and have no cell wall.
174
**True/False**.
*Mycoplasma* and *ureaplasma* exhibit _both_ antigenic variation and free radical production.
True.
175
*Mycoplasma* typically has a very _____ infectious dose.
*Mycoplasma* typically has a very **low** infectious dose.
176
What is a common cause of community-acquired ARDS?
*Mycoplasma*
177
**True/False**.
The cold agglutinins seen in *Mycoplasma* are complement-mediated.
**False**.
The cold agglutinins seen in *Mycoplasma* are ***antibody***-mediated.
178
**True/False**.
Infection with *Mycoplasma* will typically show up as an IgM response.
True.
179
*Mycoplasma* adhere to pulmonary cell sialic acid via __ \_\_\_\_\_\_\_ organelles.
They inhibit the mucociliary escalator via \_\_\_\_\_\_\_\_\_.
*Mycoplasma* adhere to pulmonary cell sialic acid via **P1** **adhesion** organelles.
They inhibit the mucociliary escalator via **_ciliostasis_**.
180
Which strain of ***Mycoplasma*** typically causes an atypical bronchopneumonia?
Which strain typically manifests as adult genitourinary infections or neonatal respiratory and genitourinary infections?
Which strain typically manifests as adult genitourinary infections only?
* Mycoplasma **pneumoniae*** (transmitted via respiratory droplets)
* Mycoplasma **hominis*** (transmitted via sexual contact)
* Mycoplasma **genitalium*** (transmitted via sexual contact))
181
Which strain of *Mycoplasma* typically manifests as adult genitourinary infections or neonatal respiratory and genitourinary infections?
What other mollicute presents similarly?
* Mycoplasma hominis*;
* ureaplasma urealyticum*
182
Where did she likely acquire TB?
How did it become reactivated?
AIDS work in South Africa;
the TNF-α inhibitor
183
Besides tuberculosis infection, what might be some other disorders in your differential?
Sarcoidosis, *Nocardia*, some fungi, etc.
184
Cell wall ________ acid – very hydro\_\_\_\_\_\_ lipid layer --- does not let ______ stain through.
Cell wall **mycolic** acid – very hydro**phobic** lipid layer --- does not let **Gram** stain through.
185
Describe the structural differences between Gram-negative, Gram-positive, and acid-fast bactera.
186
What does it mean that *Mycobacteria* are acid-fast?
Must use non-Gram-stain pigments which are then washed with acid (acid can’t make it through the lipid layer)
187
What prevents most antibiotics from entering *Mycobacteria*?
The thick, hydrophobic mycolic acid layer
188
What endo- or exotoxins do *Mycobacteria* have?
None
189
*Mycobacterium tuberculosis* requires complex, \_\_\_\_-rich media for growth (e.g. L\_\_\_\_\_\_\_\_\_\_-J\_\_\_\_\_\_; M\_\_\_\_\_\_\_\_\_).
*Mycobacterium tuberculosis* requires complex, **lipid**-rich media for growth (e.g. **Lowenstein**-**Jensen**; **Middlebrook**).
190
How is *M. leprae* grown *in vitro*?
It is not
191
What is indicated by a positive PPD test?
_Prior_ TB infection
192
Is TB transmitted via aerosols or respiratory droplets?
Aerosols
193
**Cause(s) of PPD false negatives**:
**Cause(s) of PPD false positives**:
Cause(s) of PPD false negatives: **immunocompromise** or **very recent infection** (\< 3 months)
Cause(s) of PPD false positives: **BCG**
194
Latent TB has a \_\_\_% general likelihood of lifetime reactivation, but a \_\_% likelihood *per year* for HIV/AIDS patients.
Latent TB has a **10**% general likelihood of lifetime reactivation, but a **10**% likelihood *per year* for HIV/AIDS patients.
195
Where is multi-drug resistant TB most common?
196
*Mycobacteria* virulence factors:
**Intra**cellular growth
Highly **antigen**ic mycolic acid
Prevents formation of _______________ (TB-specific)
Inhibits MHC ____ function
Prevents host \_\_\_\_\_\_sis
*Mycobacteria* virulence factors:
**Intra**cellular growth
Highly **antigen**ic mycolic acid
Prevents formation of **_phagosomes_** (TB-specific)
Inhibits MHC **_II_** function
Prevents host **_apopto_**sis
197
*Mycobacteria* virulence factors:
\_\_\_\_\_cellular growth
Highly \_\_\_\_\_\_\_\_\_ic mycolic acid
Prevents formation of **phagosomes** (\_\_\_-specific)
Inhibits MHC **II** function
Prevents host **apopto**sis
*Mycobacteria* virulence factors:
**_Intra_**cellular growth
Highly **_antigen_**ic mycolic acid
Prevents formation of **phagosomes** (**_TB_**-specific)
Inhibits MHC **II** function
Prevents host **apopto**sis
198
Name a few 'atypical' *Mycobacteria spp.* that cause TB-like disease.
Bold the more common of the three.
***M. kanasii***
***M. avium-intracellulare*** (MAC) complex
*M. scrofulaceum*
199
Name a few 'atypical' *Mycobacteria spp.* that cause soft tissue infections.
* M. marinum*
* M. ulcerans*
* M. fortuitum*
* M. abcessus*
200
What pre-disposing conditions place individuals at increased risk for infection by *M. kanasii* and *M. avium-intracellulare*?
Previous TB;
COPD;
lung malignancy
AIDS
201
**True/False**.
Non-TB *Mycobacteria* are not acid-fast and are transmitted from person-to-person.
**False**.
Non-TB *Mycobacteria **are*** ***acid-fast*** and are ***transmitted environmentally, not from person-to-person***.
202
In what countries is infection with *M. leprae* more common?
India;
Brazil
203
Which is more effective at fighting *M. leprae*, the TH1 or TH2 response?
**TH1 response**
(TH2 is less effective as the organism is intracellular)
204
**True/False**.
A vaccine is being prepared for *M. leprae*.
True.
205
Which *Mycobacteria spp.* is especially associated with AIDS?
*M. avium-intracellulare*
206
Which *Mycobacteria spp.* causes 'fish-tank granulomas'?
*M. marinum*
207
Which *Mycobacteria spp.* is associated with trauma and surgical wounds?
*M. fortuitum*
208
Hansen's disease
| (*M. leprae*)
209
Where do *M. leprae* replicate?
**Schwann** **cells** and **histiocytes**
210
What infectious agent is known as 'the great imitator'?
Why?
*Treponema pallidum*;
multiple presentations over several stages that all appear similar to multiple diseases
211
Describe the timeline of syphilis.
212
C. Check for antibodies to cardiolipin antibodies (titers decrease with treatment; although anti-treponemal antibodies will remain)
213
In infection with *T. pallidum*, __________ titers **decrease** with treatment and __________ titers **are** **unchanged** by treatment.
In infection with *T. pallidum*, **_anti-_****_cardiolipin_** titers **decrease** with treatment and **_anti-treponemal_** titers **are** **unchanged** by treatment.
214
In infection with *T. pallidum*, **anti-cardiolipin** titers __________ with treatment and **anti-treponemal** titers __________ by treatment.
In infection with *T. pallidum*, **anti-cardiolipin** titers **_decrease_** with treatment and **anti-treponemal** titers _**are** **unchanged**_ by treatment.
215
VDRL and RPR both check for ___________ (which is found in all __________ membranes).
VDRL and RPR both check for **_cardiolipin_** (which is found in all **_mitochondrial_** membranes).
216
What animals can carry *Treponema pallidum*?
Humans only
217
Which stages of syphilis are infectious?
All stages
218
**True/False**.
*Treponema pallidum* expresses LPS as a virulence factor and coats itself in a fibronectin coat to avoid detection by the immune system.
**False**.
*Treponema pallidum **does not express*** LPS as a virulence factor and coats itself in a fibronectin coat to avoid detection by the immune system (a 'self' protein).
219
The \_\_\_\_\_\_\_–\_\_\_\_\_\_\_\_\_\_ reaction is a reaction to endotoxin-like products released by the death of harmful microorganisms within the body during antibiotic treatment.
The **_Jarisch_**–**_Herxheimer_** reaction is a reaction to endotoxin-like products released by the death of harmful microorganisms within the body during **antibiotic** treatment.
220
The **Jarisch**–**Herxheimer** reaction is a reaction to endotoxin-like products released by the death of harmful microorganisms within the body during _________ treatment.
The **Jarisch**–**Herxheimer** reaction is a reaction to endotoxin-like products released by the death of harmful microorganisms within the body during **_antibiotic_** treatment.
221
Name the following *Treponema pallidum spp.* (subspecies):
**Endemic syphilis** (Bejel) --- oral papules, gummas *(Africa, Asia, Australia)*
**Yaws** --- destructive lesions of skin and bone *(Africa, Asia, South America)*
**Pinta** --- disseminated hypopigmentation --\> scarring and disfigurement
## Footnote
* T. pallidum spp. endemicum*
* T. pallidum spp. pertenue*
* T. pallidum spp. carateum*
222
Name the following *Treponema pallidum spp.* (subspecies):
***T. pallidum spp. endemicum*** --- oral papules, gummas *(Africa, Asia, Australia)*
***T. pallidum spp. pertenue*** --- destructive lesions of skin and bone *(Africa, Asia, South America)*
***T. pallidum spp. carateum*** --- disseminated hypopigmentation --\> scarring and disfigurement
**Endemic syphilis (Bejel)**
**Yaws**
**Pinta**
223
What part of *Borrelia burgdorferi* is characterized by antigenic variation?
Outer membrane proteins
224
*Borrelia burgdorferi* binds factor ___ to degrade \_\_\_\_; it also binds fibronectin. It lacks classic \_\_\_\_.
*Borrelia burgdorferi* binds factor **_H_** to degrade **_C3b_**; it also binds fibronectin. It lacks classic **_LPS_**.
225
Ixodes ticks in what stage of the lifecycle causes 90% of cases of Lyme disease?
How many cases occur due to human-to-human transmission?
**Nymph** Ixodes ticks;
**0%**
226
What parts of the U.S. have the highest rates of Lyme disease?
227
Describe what proportion of Lyme disease cases are characterized by each of the following S/Sy:
**Erythema chronicum migrans**
**Systemic symptoms**
**Severe fatigue and migratory pain**
**Nearly all**
**Some**
**50%**
228
Describe what proportion of Lyme disease cases are characterized by each of the following S/Sy:
## Footnote
**Neurologic presentation**
**Cardiac dysfunction**
**Migratory polyarthritis**
## Footnote
**15%**
**8%**
**60%**
229
**C.** (spirochetes in **salivary glands** --\> must get abdomen and head out together; suffocation is ineffective)
230
**True/False**.
The only spirochete that can be visualized via dark-field microscopy is *Treponema pallidum*.
False.
231
Is *Leptospira interrogans* aerobic or anaerobic?
**Aerobic**
232
What organism causes louse-borne relapsing fever?
Is it epidemic or endemic?
*Borrelia recurrentis* (epidemic)
233
What organism causes tick-borne relapsing fever?
Is it epidemic or endemic?
*Borrelia hermsii* (endemic)
234
What organism causes tick-borne relapsing fever?
What organism causes louse-borne relapsing fever?
* Borrelia hermsii*
* Borrelia recurrentis*
235
Why does relapsing fever occur over and over?
Antigenic variation
236
Which of the following is characterized by high bacterial levels in the blood? How about thrombocytopenia? Which is fatal?
**Lyme disease**
**Relapsing fever**
**_All_ relapsing fever**
(myocarditis is the most common cause of death)
