LEC-7 Zoonotic Bacterial Infections Flashcards
(67 cards)
1
Q
What is Brucella?
A
- A bacterial genus that, upon infection, causes Brucellosis with the following signs/symptoms:
- Fever, malaise, fatigue/weakness, headache, myalgias, anorexia leading to weight loss, granulomas, and a non-productive cough
- Also causes GI provlems such as nausea and vomiting (up to 70% of patients)
- Slow pathogenesis with a course of a few weeks
- Diagnosis is made with proper history (since bacteria is closely associated with animals such as sheep, goats, cattle, and swine)
2
Q
What are the characteristics of Brucella?
A
- Gram-negative (G-) coccobacilli
- Facultative intracellular pathogen (good for survival in human cells; prefers macrophages)
- Aerobic
- Catalase +
- Oxidase +
3
Q
Chronic brucellosis is associated with ______________.
A
Depression
4
Q
Brucella is Gram-(positive/negative).
A
Negative
5
Q
Brucella is a (bacillus/coccus/coccobacillus/spirillum).
A
Coccobacillus
6
Q
Brucella is catalase (positive/negative).
A
Catalase positive
7
Q
Brucella is oxidase (positive/negative).
A
Oxidase positive
8
Q
(T/F) Brucella is a facultative intracellular parasite.
A
True.
9
Q
What media is used to culture Brucella?
A
Blood agar OR chocolate agar
10
Q
Addition of _____________ enhances the growth of Brucella in cell culture.
A
Erythritol
11
Q
Brucella incubates (slowly/quickly).
A
Slowly
- 21-35 days
12
Q
What are the primary pathogens of Brucella?
A
- Endotoxin (LPS)
- AMP and GMP
- Superoxide dismutase
- Type IV secretion system
13
Q
What is the mechanism by which the Type IV secretion system is pathenogenic in Brucella?
A
Inhibits phagolysosome fusion (Brucella injects it’s protein ino macrophages like a syringe)
14
Q
What is the mechanism by which AMP and GMP are pathenogenic in Brucella?
A
Inhibits bacterial myloperoxidase-halide system in phagocytes (prevents phagocyte from killing bacterium)
15
Q
What is the mechanism by which superoxide dismutase is pathenogenic in Brucella?
A
Inhibits oxidative destruction of the bacterium
16
Q
What is the major virulence determinant in Bruccella and what are the two types?
A
- Endotoxin (LPS)
- Two types:
- Smooth LPS (virulent)
- Rough LPS (avirulent)
17
Q
The (smooth/rough) LPS of Brucella is relatively non-virulent as it is susceptible to lysis by normal serum.
A
Rough
18
Q
The (smooth/rough) LPS of Brucella is extremely virulent, avoiding the lysosome and surrounding itself with the cell’s ER.
A
Smooth
19
Q
Part of the body’s defense against Brucella is the formation of ____________.
A
Granulomas
20
Q
What is the typical pathogenesis for Brucella?
A
- Entry (causes abscess)
- Survival within macrophages
- Entry into lymphatics
- Draining lymph nodes
- Entry into blood stream and bacteremia
21
Q
What are the most common sites affected by systemic spread of Brucella?
A
- Liver
- Spleen
- Lymph nodes
- Bone marrow
- Kidneys
22
Q
Chronic Brucellosis may result in __________________ within the bone, liver, and kidney.
A
Suppurative (pyogenic) lesions
23
Q
Persistent elevation of which immunoglobulin is prognostic of a chronic Brucella infection?
A
IgG
24
Q
In serological diagnosis of Brucella, physicians should watch for a ___-fold rise in antibody titer, or a titer greater than ___.
A
4-fold rise in titer titer greater than 160
25
In what ways is Brucella transmitted from animals to humans?
* Direct contact with cuts or abrasion on skin
* Secretion (milk, urine, placental tissue) contact with human wound
* Inhalation of aerosols
* Unpasteurized dairy products or contaminated meat
26
Human to human transmission of Brucella is (rare/common).
Rare
27
What are common high risk occupations for Brucella infection?
* Slaughterhouse work
* Meat inspectors
* Veterinarians
* Ranchers
* Laboratory personnel
28
There are approximately ___ cases of Brucella infection per year in the U.S.
100
29
What is the primary **treatment** of **Brucellosis**?
* **Doxycycline** (tetracycline - inhibits 30S ribosomal subunit)
**AND**
* **Streptomycin** (aminoglycoside - inhibits 30S ribosomal subunit)/ **OR**
* **Rifampin** (inhibits bacterial RNA polymerase)
30
There (is/is not) a vaccine available for Brucella.
Is **NOT**
31
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ is a diverse group of small, **aerobic**, Gram-**negative** **bacilli** that are fastidious and slow-growing in specialized media. 3 of its 19 species are able to infect humans.
Bartonella
32
**Bartonella** is Gram-(negative/positive).
Negative (G-)
33
**Bartonella** is a (bacillus/coccus/coccobacillus/spirillum).
Bacillus
34
Bartonella (quintana/henselae/bacilliformis) causes **Trench** **fever** and **bacillary** **angiomatosis**. It is spread from human to human by infected **lice**.
Bartonella **quintana**
35
Bartonella (quintana/henselae/bacilliformis) causes **Oroya** **fever** and **Verruga** **Peruana**. It is transmitted by the **sand** **fly**, but remains localized to Central and South America.
Bartonella **bacilliformis**
36
Bartonella (quintana/henselae/bacilliformis) causes **cat**-**scratch** **disease**. Cats serve as a reservoir for this bacteria and may transmit infection via bites, scratches, or fleas.
Bartonella **henselae**
37
\_\_\_\_\_\_\_\_\_\_\_\_ is characterized by **mild**, relapsing fever, sudden onset of chills, headache, and maculopapular rash on the trunk and abdomen. Its symptoms last 14-30 days and it is diagnosed by **serology** or **PCR** analysis. It is more common in **alcoholics** and the **homeless**, being transmitted by **lice**.
Trench fever
* Bartonella **quintana**
38
What is the primary treatment for **Trench** **fever** caused by **Bartonella** **quintana**?
**Doxycycline** (tetracycline - inhibits 30S ribosomal subunit)
39
\_\_\_\_\_\_\_\_\_\_ occurs at a rate of 24,000 cases per year in the U.S. It is characterized by **benign**, tender **lymphadenopathy** that may become suppurative, **erythematous** **papule** at site of scratch, **skin** or **eye** **rash**, and in rare cases, **hepatosplenomegaly**. It is primarily spread by domestic or stray **cat** and is most common in children or young adults.
Cat Scratch Disease
* Bartonella **henselae**
40
The ___________ is the most common site of **lymphadenopathy** in patients with Cat Scratch Disease caused by Bartonella henselae.
Axilla
41
What are the primary methods of confirming Bartonella **henselae** in a patient suspected of Cat Scratch Disease?
* **Proper history** (hx of cat or flea contact or scratches)
* PCR analysis
* Serology
* **Biopsy** of node, skin, liver, or bone marrow showing **granulomatous** inflammation
* Positive **Warthin-Starry silver stain**
42
What is the primary treatment for **Cat Scratch Disease** caused by **Bartonella** **henselae**?
* **Azithromycin** (macrolide - inhibits 50S ribosomal subunit) for uncomplicated
* **Doxycycline** (tetracyclines**;** MOA - inhibits 30S ribosomal subunit)
* **Erythromycin** (macrolide - inhibits 50S ribosomal subunit)
**Rifampin** (inhibits bacterial RNA polymerase) in combination with **doxycycline** for **sever** cases
43
All Bartonella may infect **endothelial** cells and **induce** **angiogenesis**, but the most likely species are Bartonella __________ and \_\_\_\_\_\_\_\_\_\_.
B. **quintana** and B. **henselae**
44
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ is a condition in which lesions are characterized by **endothelial cell proliferation**, **inhibition of endothelial cell apoptosis**, and **increased secretion** of **vasoproliferative** **cytokines**. It is most often seen in **immunocompromised** patients with lesions resembling Kaposi sarcomas. Bacterial identification is made by PCR or cell culture.
Bacillary angiomatosis
* Caused by B. **quintana** or B. **henselae**
45
What is the primary treatment for **bacillary angiomatosis** caused by B. **quintana** or B. **henselae**?
* **Erythromycin** (macrolide - inhibits 50S ribosomal subunit)
OR
* **Doxycycline** (tetracycline - inhibits 30S ribosomal subunit)
46
(Oroya fever/Verruga peruana) is characterized by **acute febrile anemia**. It is caused by B. \_\_\_\_\_\_\_\_\_\_\_\_\_.
**Oroya** **fever** B. **bacilliformis**
47
(Oroya fever/Verruga peruana) is characterized by **angioprolific** **cutaneous disease** resembling bacillary angiomatosis. It is caused by B. \_\_\_\_\_\_\_\_\_\_\_\_\_.
* **Verruga** **peruana**
* B. **bacilliformis**
48
\_\_\_\_\_\_\_\_\_\_\_\_\_\_ is a Gram-**negative** **coccobacillus** that displays **bipolar** staining with **methylene** **blue**, a **positive** result on both the **catalase** and **oxidase** test, and is found as a commensal or pathogen in the nasopharynx of wild and domestic dogs, cats, and other animals.
Pasteurella
49
Most human infections by Pasteurella are caused by Pasteurella \_\_\_\_\_\_\_\_\_\_\_.
P. **multocida**
50
What are the primary virulence factors associated with **Pasteurella**?
* LPS (endotoxin)
* Neuraminidase
* Capsule (carbohydrate)
51
**Pasteurella** is Gram-(positive/negative).
Gram-**negative**
52
**Pasteurella** is a (bacillus/coccus/coccobacillus/spirillum).
**Coccobacillus**
53
**Pasteurella** is **catalase** (positive/negative).
Catalase **positive**
54
**Pasteurella** is **oxidase** (positive/negative).
Oxidase **positive**
55
**Pasteurella** grows (slow/fast) in lab culture.
Fast
56
Human infection by **Pasteurella** is most commonly associated with (bite/scratch) wounds.
**Bite**
* Pasteurella is localized to the **nasopharynx** of animals
57
Infection by _____________ causes abscess, **localized cellulitis**, and **lymphadenopathy** within 24h (**rapid**). Once bacteremia is achieved, microabscesses and/or hemorrhagic lesions in the lungs, joints, bone, and other organs result. Focal soft tissue infection, pain, swelling, and erythema may also result. In rare cases, osteomyelitis or, in older individuals, chronic respiratory infection or septic arthritis may occur.
Pasteurella **multocida**
58
What is the primary method for diagnosis of **Pasteurella** **multicoda**?
* Cell culture
* Proper history (animal exposure and bites)
59
What is the primary treatment for infection by **Pasteurella** **multicoda**?
* **Penicillin** (β-lactam - binds PBPs to inhibit cell wall synthesis)
* **Doxycycline** (tetracycline - inhibits 30S ribosomal subunit) if patient has penicillin allergy
* **Cefuroxime** (2nd gen. cephalo - binds PBPs to inhibit cell wall)
OR
* **Amoxicillin**-**Clavulanic** **acid** (β-lactam + β-lactamase inhibitor)
* Surgical **drainage** of wound
60
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ is a Gram-**positive**, **aerobic** **bacillus** with simple growth requirements. It is **catalase** **negative** and primarily associated with swine and the external slime of fish.
**Erysipelothrix rhusiopathiae**
61
**Erysipelothrix** **rhusiopathiae** is **catalase** (positive/negative).
Catalase **negative**
62
**Erysipelothrix** **rhusiopathiae** is a (bacillus/coccus/coccobacillus/spirillum).
Bacillus
63
**Erysipelothrix** **rhusiopathiae** is Gram-(positive/negative).
**Positive** (G+)
64
Erysipelothrix rhusiopathiae is transmitted by \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.
Direct cutaneous contact
* Associated with **swine** and the external **slime of fish**
65
What are the common occupations exposed to **Erysipelothrix** **rhusiopathiae**?
* Fishing industry
* Hog slaughtering
* Meat processing/butchers
* Veterinarians
* Cooks
66
\_\_\_\_\_\_\_\_\_\_\_ is a condition that is characterized by **local skin cellulitis**, pain, and symptom appearance within 2-7 days after exposure. It causes **diffuse skin eruption** and may lead to **endocarditis** if allowed to reach the blood stream. Bacterial ID is achieved by isolation of organisms from blood or tissue biopsy.
**Erysipeloid**
* Caused by Erysipelothrix **rhusiopathiae**
67
What is the primary treatment for erysipeloid caused by **Erysipelothrix** **rhusiopathiae**?
* **Penicillin** (β-lactam - binds PBPs to inhibit cell wall synthesis)
