Gram [+] Material - Random Qs Flashcards
T/F: Staphylococcus is part of the normal flora of the skin in most animals.
True
T/F: Bovine chronic mastitis, caused by Staphylococcus aureus, is associated with young cows
False
(old cows)
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
Which of the following is described as a Gram [+] pleomorphic non-spore forming human/animal pathogen?
- Staphylococcus
- Streptococcus
- Listeria
- Corynebacterium
Corynebacterium
What is the most common pyogenic organism in humans and several animal species?
Staphylococcus aureus
What is the leading pus-forming bacteria in dogs?
Staphylococcus pseudointermedius
Toxic Shock Syndrome toxin (TSST-1) is associated with which microorganism?
Staphylococcus
What are the hemolytic toxins associated with Staphylococcus?
alpha, beta, gamma, delta
complete hemolysis refers to ___-hemolysis
complete hemolysis refers to β-hemolysis
What type of hemolysis is present?
β-hemolysis
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
alpha toxin from Staphylococcus aureus produces ___-hemolysis
β-hemolysis
Name the bacteria responsible for Exudative Epidermitis (Greasy Pig Disease).
What is the key virulence factor involved?
Staphylococcus hyicus
Key virulence factor: Exfoliative toxin
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
T/F: Streptococcus is catalase positive
False.
STAPHYLOcoccus is catalase positive. Streptococcus is catalase negative, fool
The most pathogenic strains of Streptococcus produce ___-hemolysis
The most pathogenic strains of Streptococcus produce β-hemolysis
The capsule of *Streptococcus *is composed of ___________
hyaluronic acid (HA)
HA is a constituent of mammalian connective tissue
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
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
Widespread abscess formation with systemic manifestations associated with Strangles are referred to as:
Bastard Strangles
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
What is the leading cause of pneumonia, septicemia, and meningitis in primates?
Streptococcus pneumoniae
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
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*
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)
- Microbial Surface Components Recognizing Adhesive Matrix Molecules
- 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 Staphylococcus, not Streptococcus
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.
