Staph Exam Questions
What is the purpose of using immersion oil with the 100X objective?
To reduce the scattering or bending of light from the image.
Infections by this organism are predominantly hospital acquired, and some predisposing factors include catheterization, medical implantation, and immunosuppressive therapy. a. Staphylococcus aureus b. S. intermedius c. S. epidermidis d. S. saprophyticus
c. S. epidermidis
The two most common species of coagulase-negative staphylococci are: a. Staphylococcus aureus, S. epidermidis b. S. capitus, S. lugdunensis c. S. epidermidis, S. saprophyticus d.S . saccharolyticus, S. epidermidis
c. S. epidermidis, S. saprophyticus
Exfoliative is produced by Staphylococcus aureus is responsible for causing: a. Enterocolitis b. Toxic Shock Syndrome c. Scaled Skin Syndrome d. Staphylococcal Pneumonia
c. Scaled Skin Syndrome
The virulence factor that aids in CNS adhering to instruments such as catheters and prosthetic devices: a. TSST-1 b. Hyaluronidase c. Slime d. Protein A
c. Slime
Staphylococci aureus are catalase-positive, gram-positive cocci that belong in this family. What is this family? a. Micrococcaceae b. Streptococcaceae c. Staphylococcaceae d. Enterobacteriaceae
c. Staphylococcaceae
All of the following are diseases caused by S. aureus EXCEPT: a. carbuncles b. furuncles c. pharyngitis d. folicullitis
c. pharyngitis
Human carriers of S. aureus have the organism where? a. In the sputum b. In the feces c. In the nares & axilla d. In the saliva
c.In the nares & axilla
Which of the following media is both selective and differential? a.SBA b.CH c.MSA d.MH
c.MSA
Which of the following tests will rapidly differentiate micrococci from staphylococci? Staphylococcus aureus a.Catalase b.Coagulase c.Modified oxidase d.Novobiocin susceptibility
c.Modified oxidase
Slime production is associated with which of Staphylococcus species? a.Staphylococcus aureus b.Staphylococcus saprophyticus c.Staphylococcus epidermidis d.Staphylococcus intermedius
c.Staphylococcus epidermidis
Staphylococcus aureus should be: a.Resistant to penicillin b.Resistant to methicillin c.Susceptible to penicillin d.Intermediate to methicillin
c.Susceptible to penicillin
The enterotoxin produced by certain strains of hemolytic, coagulase positive Staphylococcus aureus : a.is destroyed by boiling for 15-30 minutes b.is identical to the dermonecrotic toxin c.causes one type of bacterial food poisoning d.is highly antigenic
c.causes one type of bacterial food poisoning
The most common type of clinical specimen submitted if Staphylococcus is suspected: a. wound swab b. urine c. sputum d. tissue
a. wound swab
Which Staphylococcus species, in addition to S. aureus also produces coagulase? a.Staphylococcus intermedius b.Staphylococcus saprophyticus c.Staphylococcus hominis d.All of these options
a.Staphylococcus intermedius
Detects free coagulase: a. Tube coagulase b. Clumping factor c. Slide coagulase d. All of the above
a.Tube coagulase
A drug used for MRSA infections: a.vancomycin b.penicillin c.cephalothin d.methicillin
a.vancomycin
The tests used to detect clumping factor will differentiate Staphylococcus aureus from other staphylococcal species. What are these tests? a. Novobiocin and hemolysin A b. Coagulase and latex agglutination c. Complement fixation and coagulase d. Latex agglutination and enzyme immunoassay (EIA)
b. Coagulase and latex agglutination
Enterotoxin produced by Staphylococcus aureus is responsible for causing: a. Carbuncles b. Enterocolitis c. Impetigo d. Scaled skin syndrome
b. Enterocolitis
Which of the following enzymes contribute to the virulence of S. aureus? a. Urease and lecithinase . b. Hyaluronidase and beta-lactamase c. Lecithinase and catalase d. Cytochrome oxidase
b. Hyaluronidase and beta-lactamase
Staphylococcus aureus, when present, could most likely be recovered from a stool sample if the primary plating medium included: a. Bismuth sulfite b. PEA c. Thiosulfate citrate bile salts sucrose d. Xylose-lysine-desoxycholate
b. PEA
The structure of the gram-positive cell wall allows gram positive organisms to: a. Retain safranin complexes b. Retain crystal violet-iodine complexes c. Accelerate decolorization d. Accept the counter stain
b. Retain crystal violet-iodine complexes
This staphylococcus produces wide zones of beta hemolysis on 5% sheep blood agar. a. Staphylococcus epidermidis b. S. aureus c. S. intermedius d. S. saprophyticus
b. S. aureus
This infection occurs secondary to influenza A virus, has a high mortality rate, and occurs among infants and immunocompromised patients. a. Gangrene b. Staphylococcal pneumoniae c. Staphylococcal meningitis d. Staphylococcal peritonitis
b. Staphylococcal pneumoniae
Gram stain examination from a blood culture bottle shows dark blue, spherical organisms in clusters. Growth on sheep blood agar shows small, round, pale yellow colonies. Further tests should include: a)catalase production and coagulase test b)bacitracin susceptibility and serological typing c)oxidase and deoxyribonuclease d)Voges-Proskauer and methyl red
a)catalase production and coagulase test
A drug used for MRSA infections: a)vancomycin b)penicillin c)cephalothin d)methicillin
a)vancomycin
All of the following is used to describe the colonial morphology of Staphylococcus epidermidis EXCEPT: a. Beta-Hemolytic b. Non-Hemolytic c. White d. Small to medium
a. Beta-Hemolytic
Which of the following is not associated with Staphylococcus aureus? a. Endotoxin production b. Clumping factor production c. Deoxyribonuclease production d. Hemolysin production
a. Endotoxin production
The gram stain of an egg yolk, yellow colony shows some GPC in tetrads. This organism is most likely: a. Micrococcus sp. b. S. epidermidis c. S. aureus d. E. coli
a. Micrococcus sp.
An infant is seen in the ER Department for what appears to be an umbilical infection. The infant presents with slight purulent drainage from the umbilicus and large areas of blistered skin on the face, neck, groin and trunk. The causative organism is thought to be Staphylococcus aureus. What is the probable diagnosis? a. Scalded skin syndrome b. Acquired immunodeficiency syndrome c. Toxic shock syndrome d. Reye's syndrome
a. Scalded skin syndrome
The Staphylococci may be distinguished from the Streptococci by the presence of: a. catalase b. Β-hemolysis c. coagulase d. Αlpha-hemolysis
a. catalase
Staphylococcal food poisoning is characterized by: a. rapid onset- within 2-8 hours after ingestion of the entertoxin b. colonization of the GI tract by the bacterium c. a 2 day & 2 week incubation period d. diarrhea, but no vomiting
a. rapid onset- within 2-8 hours after ingestion of the entertoxin
Colony characteristics for Staphylococcus aureus on blood agar after 18 to 24 hours incubation at 35⁰ C include all the following EXCEPT: a. swarming b. smooth c. yellow-white d. round
a. swarming
The disease that S. saprophyticus most often causes is: a. urinary tract infections b. endocarditis c. sepsis d. folliculitis
a. urinary tract infections
Infections caused by Staphylococcus aureus are suppurative, meaning: a. These infections ooze lymph fluid. b. The infection is filled with pus and necrotic tissues. c. The acute inflammatory response gorges the area with red blood cells. d. The toxins activate the coagulation system, which isolates the infection.
b. The infection is filled with pus and necrotic tissues.
Which of the following tests should be used to differentiate Staphylococcus aureus fromStaphylococcus intermedius? a.Catalase b.Acetoin c.slide coagulase test d.urease
b.Acetoin
The Clumping Factor is another name for: a. Extracellular coagulase b. Cell-bound coagulase c. Free coagulase d. Hyaluronidase
b.Cell-bound coagulase
The virulence factor that causes food poisoning: a.Leukocidin b.Enterotoxin c.Protein A d.Hyaluronidase
b.Enterotoxin
A gram stain from a 24-hr. urine culture shows gram-positive cocci in clusters. The organism tested catalase positive. To speciate this organism from culture, the technician should perform a coagulase test and a/an: a.Polymyxin B susceptibility b.Novobiocin susceptibility c.Oxidase d.Beta-lactase
b.Novobiocin susceptibility
Toxic shock syndrome is attributed to infection with: a.Staphylococcus hominis b.Staphylococcus aureus c.Staphylococcus epidermidis d.Staphylococcus saprophyticus
b.Staphylococcus aureus
Which of the following is a characteristic of staphylococci that would help in their isolation from clinical specimens? a)bile resistance b)growth at 55◦C c)high salt tolerance d)resistance to novobiocin
c)high salt tolerance
An identifying characteristic of Staphylococcus aureus is: a. DNase negative b. Coagulase negative c. Mannitol fermentation positive d. growth inhibition in presence of increased salt
c. Mannitol fermentation positive
The primary reservoir for staphylococci is: a. Ears b. Mouth c. Nares d. Throat
c. Nares
How is Staphylococcus saprophyticus presumptively identified? a. Latex agglutination test for clumping factor b. Rabbit plasma test for coagulase c. Novobiocin susceptibility d. All of the above
c. Novobiocin susceptibility
Staphylococcus sp. divide in multiple planes, most often resulting in: a. Single cells b. chains c. Pairs & clusters d. tetrads
c. Pairs & clusters
Binds the Fc portion of the immunoglobin, allowing the bacteria to avoid phagocytosis: a. Leukocidin b. Alpha hemolysis c. Protein A d. Beta hemolysis
c. Protein A
A wound culture grows GPC with the following characteristics: beta-hemolytic colonies that are both catalase & coagulase positive. What is the most likely organism? a. S. epidermidis b. S. saprophyticus c. S. aureus d. Micrococcus sp.
c. S. aureus
Selective media for the isolation of Staphylococcus includes: a. CNA b. MacConkey c. PEA d. Both a & c
d. Both a & c
What are the effects of the α-hemolysin produced by Staphylococcus aureus? a. It acts on sphingomyelin in the plasma membrane of red blood cells. b. It kills polymorphonuclear leukocytes. c. It kills macrophages. d. It lyses red blood cells, damages platelets and macrophages, and can cause severe tissue damage.
d. It lyses red blood cells, damages platelets and macrophages, and can cause severe tissue damage.
The test used to differentiate Staphylococcus saprophyticus from other members of CNS: a. Slide coagulase b. Catalase c. Tube coagulase d. Novobiocin susceptibility
d. Novobiocin susceptibility
A woman in her 20s goes to her physician complaining of burning upon urination, frequency, and general malaise. Her physician does a urine culture and it grows out 25,000 colony-forming units (CFU)/mL of a catalase-positive, coagulase-negative, novobiocin-resistant gram-positive cocci. What is the most likely pathogen? a. Staphylococcus epidermidis b. S. haemolyticus c. S. intermedius d. S. saprophyticus
d. S. saprophyticus
A multi-system disease that is associated with tampons and characterized by high fever, hypotension, and shock: a. Septic arthritis b. Bullous impetigo c. Osteomyelitis d. Toxic shock syndrome
d. Toxic shock syndrome
Staphylococcus saprophyticus, a recognized pathogen, is a cause of: a. Furuncles b. Impetigo c. Otits media d. UTI
d. UTI
Staphylococcus epidermidis (coagulase negative) is recovered from which of the following sources?a.Prosthetic heart valves b.Intravenous catheters c.Urinary tract d.All of these options
d.All of these options
Which of the following tests is used routinely to identify Staphylococcus aureus? a.Slide coagulase test b.Tube coagulase test c.Latex agglutination d.All of these options
d.All of these options
The microscopic morphology of Micrococcus sp. is: a. GPC in clusters b. GPR in tetrads c. GPC in pairs d. GPC in tetrads
d.GPC in tetrads
Urine cultured from the catheter of an 18-year-old female patient produced more than 100,000 CFU/mL on a CNA plate. Colonies were catalase positive, coagulase negative by the latex agglutination slide method as well as the tube coagulase test. The best single test for identification is: a.Lactose fermentation b.Urease c.Catalase d.Novobiocin susceptibility
d.Novobiocin susceptibility
The following results were observed by using a tube coagulase test: Coagulase at 4 hrs. = positive Coagulase at 18 hrs. = Negative DNAse = positive Novobiocin = Susceptible/Sensitive BAP: β hemolysis MSA: + (acid production) What is the most probable identification? a.Staphylococcus hominis b.Staphylococcus saprophyticus c.Staphylococcus epidermidis d.Staphylococcus aureus
d.Staphylococcus aureus
Which of the following body sites is not normally colonized by large numbers of normal flora organisms?a.colon b.skin c.vagina d.lungs
d.lungs