Gram [+] Material - Random Qs Flashcards by Chris Bessette

T/F: Staphylococcus is part of the normal flora of the skin in most animals.

True

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T/F: Bovine chronic mastitis, caused by Staphylococcus aureus, is associated with young cows

False

(old cows)

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Which of the following is NOT a characteristic of Staphylococcus?

Grow on non-enriched media
Stable in the environment
Cause pyogenic infections
Commensals on mm and skin
All of the above are characteristics of Staphylococcus

All of the above are characteristics of Staphylococcus

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Which of the following is described as a Gram [+] pleomorphic non-spore forming human/animal pathogen?

Staphylococcus
Streptococcus
Listeria
Corynebacterium

Corynebacterium

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What is the most common pyogenic organism in humans and several animal species?

Staphylococcus aureus

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What is the leading pus-forming bacteria in dogs?

Staphylococcus pseudointermedius

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Toxic Shock Syndrome toxin (TSST-1) is associated with which microorganism?

Staphylococcus

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What are the hemolytic toxins associated with Staphylococcus?

alpha, beta, gamma, delta

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complete hemolysis refers to ___-hemolysis

complete hemolysis refers to β-hemolysis

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What type of hemolysis is present?

β-hemolysis

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The typical lesion associated with Staphylococcus is the:

abscess!

inflammatory focus in which participating cells have been destroyed by the combined effect of bacterial and inflammatory cell activity

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alpha toxin from Staphylococcus aureus produces ___-hemolysis

β-hemolysis

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Name the bacteria responsible for Exudative Epidermitis (Greasy Pig Disease).

What is the key virulence factor involved?

Staphylococcus hyicus

Key virulence factor: Exfoliative toxin

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Name the bacteria that causes bumblefoot in gallinaceous birds

Staphylococcus aureus

Bumblefoot is a chronic pyogranulomatous process in subcutaneous tissues of the foot resulting in thick-walled swellings on one or more joints

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T/F: Streptococcus is catalase positive

False.

STAPHYLOcoccus is catalase positive. Streptococcus is catalase negative, fool

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The most pathogenic strains of Streptococcus produce ___-hemolysis

The most pathogenic strains of Streptococcus produce β-hemolysis

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The capsule of *Streptococcus *is composed of ___________

hyaluronic acid (HA)

HA is a constituent of mammalian connective tissue

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M-protein, one of the major virulence factors in Streptococcus, is anti-phagocytic by binding __________ and ____________

M-protein, one of the major virulence factors in Streptococcus, is anti-phagocytic by binding fibrinogen and Factor H

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Which Streptococcus species is responsible for genital & mastitic infections and STRANGLES in horses?

Streptococcus equi subsp. equi

Strangles is a highly contagious febrile rhinopharyngitis involving abscessation of regional lymph nodes

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Widespread abscess formation with systemic manifestations associated with Strangles are referred to as:

Bastard Strangles

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T/F: Staphylococcus agalactiae is an extremely important causative agent of mastitis

False

Streptococcus agalactiae is an extremely important causative agent of mastitis

Not Staphylococcus

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What is the leading cause of pneumonia, septicemia, and meningitis in primates?

Streptococcus pneumoniae

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You are presented with a five-year-old cocker spaniel with a history of persistent pyoderma. You collect samples from the edge of the lesion and upon microscopic examination observe Gram positive coccoid bacteria. As part of your differential diagnosis in this case you should have:

Streptococcus canis
Staphylococcus aureus
Staphylococcus pseudointermedius
All of the above
None of the above

All of the above

All of the agents can cause pyoderma, all can be found in a dog, and all are Gram-positive

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You are presented with a five-year-old cocker spaniel with a history of persistent pyoderma. You collect samples from the edge of the lesion and upon microscopic examination observe Gram positive coccoid bacteria, and upon isolation and biochemical characterization the isolate is catalase positive. The most likely agent in this case is:

Staphylococcus hyicus
Staphylococcus aureus
Staphylococcus pseudointermedius
Streptococcus canis

Staphylococcus pseudointermedius

S. hyicus is mostly found in pigs*
S. canis is catalase negative*

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T/F: *Corynebacterium* is acid fast

**False**. Corynebacterium is non-acid fast

I say "chinese letters," you say:

*Corynebacterium* or at least you ought to

Name the exotoxin present in *Corynebacterium *that increases vascular permeability, aids in the spread of the bacteria, inactivates complement, and inhibits chemotaxis:

**Phospholipase D (PLD)** **\*\*remember dat shit**

The virulence of Corynebacterium is primarily contributed to ___________ and \_\_\_\_\_\_\_\_\_\_\_

The virulence of Corynebacterium is primarily contributed to **phospholipase D (PLD)** and **cell wall lipids**

Name the condition characterized by chronic abscessation of peripheral lymph nodes in sheep

**Caseous lymphadenitis**

Name the serodiagnostic test used for *Corynebacterium*

**Synergistic hemolysis inhibition test** Has inhibitory effects of staphylococcal beta toxin and synergistic hemolysis with *Rhodococcus equi*

Name the key virulence factor for Corynebacterium, responsible for catalyzing the hydrolysis of urea into carbon dioxide and ammonia

**urease**

Which bacteria produces the "chinese-letter" arrangement seen in the image?

*Corynebacterium*

*Staphylococcus *α-toxins produce \_\_-hemolysis

Staphylococcus α-toxins produce **_β-hemolysis_**

*Staphylococcus* beta toxins produce \_\_-hemolysis

*Staphylococcus* beta toxins produce **_α-hemolysis_**

What bacteria is present in the image (looks like "grape-like" clusters)?

*Staphylococcus*

Which of the following laboratory tests would you use to distinguish definitively between *Staphylococcus aureus* and *Streptococcus dysgalactiae*? * CAMP test * catalase * motility * oxidase * urease

**catalase test** * Staphylococcus* is catalase _positive_ * Streptococcus* is catalase _negative_

In 2005 the People’s Republic of China reported the largest known outbreak in humans of a bacterial infection aquired from swine. There were over 200 cases of human disease of which roughly 40 were fatal. What was the organism? * *Bacillus cereus* * *Clostridium difficile* * *Staphylococcus hyicus* * *Streptococcus porcinus* * *Streptococcus suis*

***Streptococcus suis*** \*\*see case reports for *Streptococcus ("Streptococcus suis* meningitis, Hawaii")\*\*

*Staphylococcus aureus* is a well recognized cause of all of the following disease conditions except: * food poisoning in man * mastitis in cattle * meningitis in pigs * otitis in dogs * tick pyemia in lambs

meningitis in pigs

T/F: All pathogenic *Staphylococcus* produce the enzyme **coagulase**

**False** THERE ARE NON-COAGULASE PATHOGENIC STRAINS!

What do we consider to be the most important virulence factor for *Staphylococcus*?

**Adhesins (MSCRAMMS)** * **_M_**icrobial **_S_**urface **_C_**omponents **_R_**ecognizing **_A_**dhesive **_M_**atrix **_M_**olecules * Several are produced, giving some affinity for certain tissues (bone, kidney, bladder) * Bind to a bunch of host extracellular matrix proteins (fibronectin, fibrinogen, collagen, laminin)

Name the Staphylococcal virulence factor that causes **staphylococcal scalded skin syndrome** in infants and may be involved in **porcine exudative epidermititis**

**Exfoliative toxins** (serine proteases) * Target the **intercellular adhesion protein (Desmoglein)** found only in the epidermis

T/F: *Staphylococcus aureus *is capable of reverse zoonosis

**True** Methicilin-resistant *Staphylococcus aureus* (MRSA) was diagnosed in a 76-year- old man. Transmission occurred between the man and his 8 year old lab. Transmission between people and their pets is becoming more common. MRSA in pets is closely linked with MRSA in people. \*\*See reverse zoonosis case study on eCollege\*\*

Catalase converts __________ to \_\_\_\_\_\_\_\_\_\_\_\_

Catalase converts hydrogen peroxide to oxygen & water

T/F: Catalase is produced by Streptococcus, but not Staphylococcus

**False.** Catalase is produced by **Staph**ylococcus, _not_ **Strep**tococcus

What appears to be a key virulence factor for *Staphylococcus aureus* causing **bovine mastitis**?

alpha toxin! \*\**Staphylococcus aureus* is the LEADING CAUSE of bovine mastitis\*\*

A chronic presentation of *Staphylococcus*, where tissues become thick/hard with multiple small abscesses containing actinomycosis granules, is called:

**Botryomycosis** gross

Inoculation of indigenous skin *S. aureus* by tick bites causes ____________ in lambs

tick pyremia

T/F: Antimicrobial resistance has not yet been a concern for *Staphylococcus*

False... Like, not even close to being true

T/F: Streptokinases act to inhibit the spread of *Streptococcus*

FALSE. Streptokinases help SPREAD the organism

Streptococcus triggers inflammatory processes that lead to \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

Streptococcus triggers inflammatory processes that lead to **suppuration** and **abscess formation**

Suppurative osteomyelitis is caused by:

*Streptococcus equi* subsp. *Zooepidemicus*

What test is used to test for **hemolytic syngergism**?

CAMP test

Lipoteichoic acids and peptidoglycan (both part of the cell wall of *Corynebacterium*) are \_\_\_\_\_-inflammatory (pro or non)

Lipoteichoic acids and peptidoglycan are **_pro_**-inflammatory

Ovine posthitis is also known as \_\_\_\_\_\_\_\_\_\_ What is it caused by?

**pizzle rot** and **sheath rot** no, I'm really not even kidding It is a necrotizing inflammation of the prepuce and adjacent tissues. Ammonia is thought to initiate the inflammatory process Caused by: *Corynebacterium renale* group

T/F: *Corynebacterium renale* group is characterized partly by its absence of ureases

No. UREASE IS THE KEY VIRULENCE FACTOR FOR *CORYNEBACTERIUM RENALE*

What does **pleomorphic** mean?

Pleomorphism is the ability of some bacteria to alter their shape or size in response to environmental conditions.

Exfoliative toxins, important in *Streptococcus equi, *target the intercellular adhesion protein ____________ found only in the epidermis

Exfoliative toxins, important in Streptococcus equi, target the intercellular adhesion protein **_Desmoglein_** found only in the epidermis Causes Staphylococcal scaled skin syndrome in infants and may be involved in porcine exudative epidermitis

Regarding *Staphylococcus*, which virulence factor is utilized in the **coagulase test**?

**Clumping factor** Clumping factor interacts with fibrinogen and produces an agglutination-like reaction (used in the **coagulase test**)

Regarding *Staphylococcus aureus*, **Protein A** binds the ____ fragments of immunoglobulins. What does this binding accomplish?

Protein A binds the **Fc fragments** of immunoglobulins. This interaction is _protective_. It is anti-phagocytic in that it disguises the bacteria and protects it from opsonization

Toxic shock syndrome toxin (TSST-1) is a ____________ that crosses mucous membranes and causes endothelial damage

Toxic shock syndrome toxin (TSST-1) is a **_superantigen_** that crosses mucous membranes and causes endothelial damage

What type of hemolysis is present?

Gamma-hemolysis

What type of hemolysis is present?

alpha-hemolysis

Is *Cryptococcus neoformans* a yeast or a mold?

Yeast

T/F: *Aspergillus* spp, a common yeast, usually forms **large fluffy colonies** on lab media and produce aerial fruiting hyphae that bear asexual spores

False. T/F: *Aspergillus* spp is a **_mold_**, NOT a yeast. The rest of the statement is correct (usually forms large fluffy colonies on lab media and produce aerial fruiting hyphae that bear asexual spores)

This secondary abscess on the right hindlimb of an Arabian oryx is caused by an infection by:

*Corynebacterium pseudotuberculosis* \*\*See case studies on eCollege\*\* (this big-ass abscess is also from *C. pseudotuberculosis*)

Shown in the image is an 8-year-old Labrador retriever with extensive neck swelling, ulcerations, and purulent discharge. Upon culture of the exudate and a macerated skin biopsy specimen, the lab found that it was caused by _____________________ that the dog had contracted from its 76-year old owner

Methicillin-resistant *Staphylococcus aureus* (MRSA) \*\*See case studies on eCollege\*\*

Identify the organism. These Gram-positive cocci, mostly found in pairs and short chains, were found in the cerebrospinal fluid of a 34-year-old man with meningitis

*Streptococcus suis* \*\*see case studies on eCollege for *S. suis* zoonosis\*\*

This hemorrhagic pneumonia found in a sled dog was caused by:

*Streptococcus equi* subsp. *zooepidemicus* \*\*See case studies on eCollege\*\*

I say "Diphteroid bacteria that colonize the lower genital tract of cattle and sheep," and you say:

*Corynebacterium renale*

A diptheroid isolate from urine capable of producing an alkaline shift (indicating urea hydrolysis) within minutes of inoculation and fermenting glucose probably belongs to *which group of microorganisms*?

*Corynebacterium renale* group

A piglet presents with thick, brown flaky skin exudate located on the ears and face. Which organism is suspected?

***Staphylococcus hyicus*** Causes Exudative epidermitis (Greasy Pig Disease)

Which cell product of *Streptococcus* is pore-forming and responsible for β-hemolysis on Blood agar plates?

**Streptolysin**

A foal presents with serous nasal discharge, fever, pain, cough and anorexia. What is the most likely diagnosis?

*Streptococcus equi* subsp. *equi* | (strangles)

What zoonoses do *Streptococcus* spp. cause in humans?

**Acute glomerulonephritis** and **rheumatic fever**

In sheep and goats, *C. pseudotuberculosis* causes what characteristic appearance?

Onion ring appearance This is chronic abscessation of peripheral lymph nodes (**Caseous lymphadenitis**). Inflammatory cells traverse the capsule peripherally, adding layer of suppuration and a new capsule. Old lesions acquire thick fibrous capsule.

A sheep presents with preputial swelling and urine retention in the sheath. What is the causative agent, and what could have led to this condition?

*C. renale* caused by feeding the animal a high protein diet

Lipoteichoic acids and peptidoglycan (both part of the cell wall of \_\_\_\_\_\_\_\_\_\_\_\_) are pro-inflammatory

*Corynebacterium*

Why would **Mannitol Salt Agar** be used in diagnosis for Staphylococcus?

The high concentration of salt (7.5%) in Mannitol Salt Agar selects for members of Staphylococcus, since they can tolerate high saline levels. Organisms from other genera may grow, but they typically grow very weakly.