question
What are the general characteristics of fastidious gram negative rods?
answer
-Family Pasteurellaceae
-Gram negative coccoid to rod-shaped
-Aerobic to facultatively anaerobic
-Convert nitrate to nitrite
-Gram negative coccoid to rod-shaped
-Aerobic to facultatively anaerobic
-Convert nitrate to nitrite
question
What are the oxidase and catalase results for fastidious GNRs?
answer
oxidase and catalase positive
question
What does the gram stain of Haemophilus species look like?
answer
gram-negative pleomorphic coccobacilli or rods - occasionally long filamentous rods from colony growth
question
Haemophilus reactions
answer
-Nonmotile
-Oxidase and catalase +
-Nitrate reduction
-Ferment carbs
-Oxidase and catalase +
-Nitrate reduction
-Ferment carbs
question
What are 3 of the most important Haemophilus species that cause human infection?
answer
H. influenzae, H. aegyptius and H. ducreyi
question
What do Haemophilus species need to grow?
answer
X and V factors - grow on chocolate, not BAP
question
In regards to the Haemophilus bacteria, what does "para" mean?
answer
require only V factor, produces X factor (H. parainfluenzae)
question
Why do Haemophilus organisms not grow on SBA (BAP)?
answer
NADases present in BAP destroy V factor
question
What is satellitism?
answer
growth of a fastidious organism around other bacteria that release the necessary growth factors or breakdown toxic products
question
What organisms release the factors or naturally produce V factor?
answer
s. aureus, s. pneumoniae, Neisseria species
question
All clinically significant Haemophilus require V factor (displaying satellitism) except _____________.
answer
H. ducreyi
question
Which flora makes up 10% of normal flora in the upper respiratory tract in adults, 2-6% in children (daycare centers higher %) and convert from encapsulated to nonencapsulated strains as they mature?
answer
Haemophilus spp.
question
What are the virulence factors of Haemophilus sp?
answer
-Capsule (serotypes A-F, B most invasive)
-IgA protease
-Outer membrane proteins and LPS
-Adherence
-IgA protease
-Outer membrane proteins and LPS
-Adherence
question
What does the capsule of Haemophilus spp contain?
answer
ribose, ribitol, and phosphate (antiphagocytic and anticomplement activity)
question
Which bacteria primarily causes disease in children, causes bacteremia and spread to other tissues, and has a vaccine for a serotype?
answer
Haemophilus influenzae serotype b (Hib)
question
Which bacteria causes issues in the epiglottis, causing acute inflammation and swelling (airway obstruction), sometimes requiring an emergency tracheostomy?
answer
Haemophilus influenzae
question
What can cause Brazilian purpuric fever (BPF)?
answer
H. influenzae biogroup aegyptius
question
What is Brazilian purpuric fever?
answer
occurs in warm tropical climates, rare
-recurrent conjunctivitis, high fever, vomiting, petechiae, purpura, septicemia, and shock
-high mortality rate (up to 70%)
-recurrent conjunctivitis, high fever, vomiting, petechiae, purpura, septicemia, and shock
-high mortality rate (up to 70%)
question
Why is H. influenzae plated on chocolate agar with bacitracin?
answer
helps inhibit other organisms, especially respiratory flora
question
What is H. aegyptius plated with?
answer
chocolate agar supplemented with 1% isovitaleX
question
What is H. ducreyi plated with?
answer
GC agar (hemoglobin, FBS, vancomycin to reduce genital flora)
question
What do colonies of Haemophilus look like?
answer
translucent, moist, convex
-mousy/bleach like odor
-mousy/bleach like odor
question
What does the gram stain of H. ducreyi look like?
answer
gram negative coccobacilli arranged in groups
"school of fish"
"school of fish"
question
If Haemophilus sp don't require X factor, what do they have?
answer
Porphyrin (makes X factor)
question
What shows as a positive porphyrin test?
answer
Kovac's Reagent - red color in lower portion of tube
Wood UV lamp - fluoresce reddish orange
Wood UV lamp - fluoresce reddish orange
question
What test is done for Haemophilus sensitivity to antimicrobials?
answer
Beta-lactamase test
question
What are possible treatments for Haemophilus?
answer
Cefotaxime or ceftriaxone
-alternative: trimethoprim sulfamethoxazole, imipenem, ciprofloxacin, and chloramphenicol
-alternative: trimethoprim sulfamethoxazole, imipenem, ciprofloxacin, and chloramphenicol
question
What is a treatment for H. ducreyi?
answer
Erythromycin
question
"Foam loving"
answer
Aggregatibacter aphrophilus
question
What is primarily an animal pathogen but found in human oral cavity, nonmotile gram-negative coccobacilli, with a star formation in the center of the colonies?
answer
Aggregatibacter actinomycetemcomitans
question
What are characteristics of A. actinomycetemcomitans?
answer
Ferments carbs (not lactose or sucrose) in serum
-catalase positive, oxidase variable
-no growth on MAC
-Urease, indole, esculin and citrate negative
-Star-shaped centers on colonies
-catalase positive, oxidase variable
-no growth on MAC
-Urease, indole, esculin and citrate negative
-Star-shaped centers on colonies
question
"Rosette" morphology, pleomorphic, nonmotile, gram negative bacillus, normal flora of the nose, mouth and throat?
answer
Cardiobacterium hominis
question
What bacteria is normal flora of oral and bowel cavities
(fight - clenched fist, bite wounds)?
(fight - clenched fist, bite wounds)?
answer
Eikenella corrodens
question
Bleachlike odor with yellow colonies pitting the agar
answer
Eikenella corrodens
question
What are the characteristics of Eikenella corrodens?
answer
-Nonmotile
-Nonfermenter
-Oxidase + and catalase -
-Lysine decarboxylase +
-Ornithine decarboylase +
-Arginine decarboxylation -
-Nonfermenter
-Oxidase + and catalase -
-Lysine decarboxylase +
-Ornithine decarboylase +
-Arginine decarboxylation -
question
What are characteristics of the Kingella species?
answer
-Coccobacilli or short rods in pairs or chains
-Nonmotile but may twitch
-Oxidase +
-Catalase -
-Sugar fermenters
-Nonmotile but may twitch
-Oxidase +
-Catalase -
-Sugar fermenters
question
What may grow on Thayer Martin medium and resemble N. gonorrhoeae?
answer
Kingella dentrificans
question
What are the characteristics of Kingella dentrificans?
answer
-Glucose +
-Reduces nitrate +
-Urease, Indole, esculin, gelatin and citrate -
-Reduces nitrate +
-Urease, Indole, esculin, gelatin and citrate -
question
What is in isolates of children less than 5 years old, negative for sucrose and positive for glucose and maltose?
answer
Kingella kingae
question
What was previously called DF-1 and DF-2 (dysgonic fermenters)?
answer
Capnocytophaga
question
What are gram-negative bacilli, often fusiform, that may resemble fusobacterium and are facultatively anaerobic, requiring CO2?
answer
Capnocytophaga
question
What bacteria causes zoonosis, contains five serogroups A-F, and is a gram-negative pleomorphic coccobacilli with bipolar staining?
answer
Pasteurella multocida
question
What organisms has a musty odor and is a nonhemolytic mucoid colony with narrow green or brown halo on BAP and chocolate agar?
answer
Pasteurella multocida
question
What bacteria colonizes the URT and GI tract of mammals and birds, from exposure from dog and cat bites or scratches?
answer
Pasteurella multocida
question
What are the biochemical reactions for Pasteurella multocida?
answer
-Nonmotile
-Catalase and oxidase +
-Glucose fermentation
-Catalase and oxidase +
-Glucose fermentation
question
What are the most common species of Brucella for humans?
answer
B. melitensis, B. abortus, B. canis and B. suis
question
What are the biochemical characteristics of Brucella?
answer
-Strict aerobes (some require CO2)
-Nonspore forming gram-negative coccobacilli
-Nonmotile, nonencapsulated, intracellular parasites
-Nonspore forming gram-negative coccobacilli
-Nonmotile, nonencapsulated, intracellular parasites
question
What are the test reactions for Brucella?
answer
-Oxidase and catalase +
-H2S production and urease help differentiate types
-H2S production and urease help differentiate types
question
What is tularemia and what is it associated with?
answer
Francisella sp. - acute febrile, granulomatous disease with rapid onset and flulike symptoms - "Rabbit Fever"
question
What are the characteristics of Francisella?
answer
-Facultative intracellular parasite
-Nonmotile
-small, gram-negative coccobacilli
-strict aerobe
-Nonmotile
-small, gram-negative coccobacilli
-strict aerobe
question
What are the four subspecies of Francisella tularensis?
answer
Type A - more virulent
Type B - Holarctica
Mediasiatica
Novicida
Type B - Holarctica
Mediasiatica
Novicida
question
What are the biochemical reactions of Francisella?
answer
-gram negative
-oxidase negative
-urease negative
-X and V negative
-Catalase weak positive
-oxidase negative
-urease negative
-X and V negative
-Catalase weak positive
question
What diseases are Legionella pneumophila associated with?
answer
Legionnaires' disease and Pontiac fever
question
Where can Legionella pneumophila be found?
answer
environmental water sources and air conditioning systems
question
Most cases of Legionnaires' disease are serogroup ____.
answer
Serogroup 1
question
What is Pontiac fever?
answer
mild form of Legionella - doesn't generally lead to mortality but spontaneous recovery
question
What do you culture on if Legionella is suspected?
answer
BCYE - Buffered charcoal yeast extract
question
What are the virulence factors of Bordatella?
answer
-filamentous hemagglutinin (FHA)
-Pertussis toxin
-Adenylate cyclase toxin
-Tracheal cytotoxin
-Pertussis toxin
-Adenylate cyclase toxin
-Tracheal cytotoxin
question
What is used to culture Bordatella?
answer
Bordet-Gengou potato infusion agar with glycerol and sheep blood
-alternative: charcoal agar with 10% horse blood and cephalexin
-alternative: charcoal agar with 10% horse blood and cephalexin
question
What do colonies of Bordatella look like on agar?
answer
mercury droplets
question
What is used to treat Bordatella?
answer
Erythromycin
Order an Essay Now & Get These Features For Free:
Turnitin Report
Formatting
Title Page
Citation
Outline
