Unit 2 Flashcards
A gram positive cocci recovered from a urine culture of a 15 year old girl is alpha hemolytic, bile esculin positive and optochin negative and is most likely:
E. faecalis
The primary reservoir for S. aureus is the:
anterior nares
Which enzymes contribute to the virulence of S. aureus?
hyaluronidase and coagulase
True or False?
The normal habitat of Bacillus anthracis is the human nasopharynx.
False
Which morphologic feature is a major cinsideration in determining an identification strategy for streptococci?
Hemolytic pattern
Which group of streptococci is associated with the production of pyrogenic exotoxin (SPE) and Streptokinase?
Group A
True or False?
Initial symptoms of staphylococcal poisoning will occur 2-6 hours after eating contaminated food.
True
A black eschar on the skin is indicative of what condition.
Cutaneous anthrax
The organism that exhibits characteristic end over end tumbling motility when incubated in nutrient broth at room temperature for 1-2 hours is:
Listeria monocytogenes
The CAMP factor is produced by:
Streptococcus agalactiae
Micrococcus luteus will produce which of the following results when a modified oxidase test is performed:
blue/purple color
Patients who are immunocompromised and pregnant women should avoid eating soft cheeses such as Mexican-style, feta, brie, Camembert and blue veined cheese to prevent:
foodborne listeriosis
An organism recovered from a case of pharyngitis (sore throat) in an 8 year old child is beta hemolytic, catalase negative and has a gram positive cocci chain gram stain. Which test would be performed next to further identify this organism?
Lancefield grouping by latex agglutination
S. saprophyticus is best differentiated from S. epidermidis by resistance to:
Novobiocin
All of these organisms are associated with gastrointestinal infections except: Bacillus anthracis Listeria monocytogenes Staphylococcus aureus Streptococcus pyogenes
Streptococcus pyogenes
A wet mount and gram stain of vaginal secretions of a patient with bacterial vaginosis caused by Gardnerella vaginalis will likely reveal:
Large squamous epithelial cells with numerous attached gram variable or gram negative coccobacilli and rods
True or False?
Sodium desoxycholate will not dissolve colonies of viridans streptococci on sheep blood agar.
True
The bacterial species that can be described as able to grow in 6.5% NaCL and 40% bile and hydrolyze esculin, is part of the normal gastrointestinal flora of animals and humans, frequently nonhemolytic, and is a major cause of nosocomial infections is:
E. faecalis
True or False?
Lancefield group testing by latex agglutination is appropriate for alpha heolytic, catalase negative, gram positive cocci.
False
This aerobic gram positive rod may cause conjuctivitis, gastroenteritis, meningitis and neonatal sepsis.
Listeria monocytogenes
Gram positive rods that are palisading and are typical of:
Corynebacterium diptheriae
This alpha hemolytic gram positive rod is frequently considered a contaminant and is normal flora of the human mouth and female genital tract. It is:
Lactobacillus sp.
The tube coagulase test:
detects extracellular coagulase (free coagulase)
The first identification test performed on a clinical isolate of a gram-positive cocci that is catalase-positive would likely be the:
coagulase test
The optochin test causes a zone of greater than 14mm with which organism?
S. pneumoniae
A patient has several bloodstream cultures growing beta hemolytic, catalase positive, gram positive cocci. It is coagulase negative by the slide coagulase test. What is the most appropriate action to identify this organism?
do a tube coagulase to confirm the slide test
This organism is not considered to be part of the normal flora of humans:
S. pyogenes
An organism that has a gram stain of gram positive cocci in pairs is most likely:
S. pneumoniae
What type of motility reaction, associated with Listeria, is known as:
Umbrella
The gram stain of LIsteria monocytogenes may be confused with streptococci, the organisms are rapidly differentiate by this test:
Catalase
What mode of transmission has not been associated with B. anthracis infection?
Person to person
True or False?
Group A Streptococcus is PYR positive and CAMP postive.
False
A non-spore forming, catalase negative, gram positive rod that produced hydrogen sulfide was isolated from a finger abcess of a farm worker. The organism is likely:
Erysipelothrix rhusiopathiae
A 3 day old infant is symptomatic of meningitis, which organism is most likely the cause?
Streptococcus agalactiae
Which of the following infections is least likely to be associated with S. aureus? Neonatal Sepsis Osteomyelitis Foodpoisoning Toxic Shock Syndrome
Neonatal Sepsis
The gram stain morphology of Staphylococcus epidermidis is typically:
Gram positive cocci in clusters
Optochin, bile solubility, bile esculin, and 6.5% NaCl are tests most likely performed on:
alpha-hemolytic streptococcus
The catalase test is used to differentiate which groups of organisms?
Staphylococcus from Streptococcus
A patient is admitted to the hospital with a persistent cough, fever and chills. Sputum cultures were collected and subsequently grew and organism with the following results: blood agar - mucoid, alpha hemolytic colonies chocolate - growth MacConkey - no growth PEA - light growth Gram stain - gram pos cocci in pairs (diplococci) catalase - neg bile esculin - negative 6.5% salt - negative bile solubility - lysis of the colony Optochin zone - 16mm The most likely identification is:
Streptococcus pneumoniae
An oncology patient receiving chemotherapy was seen by her physician for a soft tissue infection of her lower leg. A routine culture grew the folowing: blood agar - beta hemolytic colonies PEA and Thioglycollate - growth MacConkey - no growth Gram stain - gram positive cocci catalase - negative PYR - negative Motility negative CAMP test - positive Bile esculin - negative What is the most likely presumptive ID?
Streptococcus agalactiae
An organism was recovered from a blood culture of a 41 year old female cattle rancher from South America. The patient was in acute respiratory distress and experiencing multiple organ failure. The lab results were:
Gram stain - large gram positive rods with spores
The plates were than handled using special precautions.
Colonies on aerobic blood agar plate are nonhemolytic with swirling progections.
PEA - growth
MacConkey - no growth
H2S negative
Motility - negative
The organism was sent to the Virginia Consolidated labs for further ID.
What is the expected ID of this organism?
Bacillus anthracis
A wound culture of a 17 year old football player is growing a pure culture of an organism with the following results: blood agar - cream colored, beta hemolytic colonies growth on PEA no growth on MacConkey Gram stain - GPC in clusters Catalase - positive CAMP - negative PYR Test - negative Slide coagulase - negative Novobiocin - sensitive Tube coagulase - positive
S. aureus
Heavy growth of a bacteria was recovered from a urine culture of a 29 year old female. The following results were observed: blood agar - pure culture of a white non hemolytic colony PEA - growth MacConkey - no growth Gram stain - GPC Catalase - positive Slide coagulase - negative Tube coagulase - negative Novobiocin - resistant Modified oxidase - neg
Staphylococcus saprophyticus
Match the organism with the appropriate disease or infection:
Severe conjuctivitis, corneal ulceration
Listeria monocytogenes
Match the organism with the appropriate disease or infection:
Otitis media
Streptococcus pneumoniae
Match the organism with the appropriate disease or infection:
Nosocomial UTI
Enterococcus faecalis
Match the organism with the appropriate disease or infection:
Carbuncles
Staphylococcus aureus
Match the organism with the appropriate disease or infection:
Bacterial vaginosis
Gardnerella vaginalis
Match the organism with the appropriate disease or infection:
Scarlet fever
Streptococcus pyogenes
Match the organism with the appropriate disease or infection:
Cellulitis in butchers
Erysipelothrix rhusopathiae
Match the organism with the appropriate disease or infection:
Wool sorter’s disease
Bacillus anthracis
Match the organism to the appropriate media:
PLAT
Bacillus anthracis
Match the organism to the appropriate media:
Cysteine tellurite
Corynebacterium diphtheriae
Match the organism to the appropriate media:
Oxford
Listeria monocytogenes
Match the organism to the appropriate media:
Human blood bilayer tween
Garderella vaginalis
The red line alert test is an immunochromatographic test that will presumptively identify:
Bacillus anthracis
Stabbing the loop into the blood agar after streaking could allow colonies to display hemolysis caused by:
Streptolysin O
