Unit 3 Flashcards
The following reactions were observed on the LIA of a stool being screened for Salmonella; Purple slant and purple butt or K/K. The interpretation is:
LDA negative, LDC positive
Infections with this organism often mimics appendicitis:
Yersinia enterocolitica
True or False?
An indole test will differentiate Proteus mirabilis from Proteus vulgaris
True
What organism is lactose negative, oxidase negative and H2S negative?
Shigella sonnei
This lactose negative organism produces hydrogen sulfide (H2S) and may cause “antibiotic diarrhea” due to multiple drug resistance and also chronic urinary tract infections:
Proteus mirabilis
The expeced results of a positive oxidase test will be:
dark purple color
An organism displaying swarming motility on BAP is most likely which organism?
Proteus mirabilis
Voges - Proskauer testing detects which end product of glucose fermentation?
Acetoin
A Mac/Sorbitol plate was obtained from a stool culture. There were both pink and clear colonies growing on the plate. Which colonies should be referred for further ID?
Clear colonies
The ability to produce H2S makes this organism unique among slow lactose fermenting organisms
Citrobacter freundii
When using a database as in the API20E for identification of unknown isolates, the profile must be convered to:
Numeric codes
This oxidase positive organism has a blue/green pigment and is associated with chronic respiratory infections in Cystic Fibrosis patients:
Pseudomonas aeruginosa
The primary reservoir for Vibrio spp. is:
Marine (salt) or brackish water
Which combination of tests BEST differentiate Shigella from Proteus?
H2S, motility, urea, lysine deaminase
An organism was inoculated to a TSI slant and gave the following reactions:
Alkaline slant/Acid butt, H2S produced, gas produced
What is the most likely organism?
Salmonella enteriditis
True or False?
Acinetobacter species usually exhibits a deep red pigment on MacConkey agar.
False
What characteristic is NOT a qualification to be included among the Enterobacteriaceae family? Glucose fermenation Conversion of nitrate to nitrites Fermentation of Lactose Oxidase negative Gram negative rods
Fermentation of Lactose
An organism with a positive indole test hast the ability to split this compound to form indole.
Tryptophan
All of these organisms are oxidase positive except: Pseudomonas aeruginosa Vibrio cholerae Eikenella corrodens Shigella sonnei
Shigella sonnei
Which organism is not usually associated with the ingestion of contaminated food products?
Eikenella corrodens
Match the media with the correct organism or purpose: Pick the BEST MEDIA.
Isolation of EHEC 0157:H7
MacConkey Sorbitol agar
Match the media with the correct organism or purpose: Pick the BEST MEDIA.
Isoltaion of Yersinia enterocolitica
CIN agar
Match the media with the correct organism or purpose: Pick the BEST MEDIA.
Isolation of Vibrio cholerae
TCBS agar
Match the media with the correct organism or purpose: Pick the BEST MEDIA.
Demonstrate lysine deamination
LIA
Match the media with the correct organism or purpose: Pick the BEST MEDIA.
Demonstrate glucose and sucrose fermentaiton
TSI
Match the media with the correct organism or purpose: Pick the BEST MEDIA.
Selective and Differential isolation of Salmonella/Shigella
HE agar
Match the following disease states with the corresponding organism.
Human bite wound infections
Eikenella corrodens
Match the following disease states with the corresponding organism.
Hemolytic Uremic Syndrome
E. coli
Match the following disease states with the corresponding organism.
Dog bite wound
Pasturella multocida
Match the following disease states with the corresponding organism.Multiple Drug resistant Respiratory infection - Active military (Iraq)
Acinetobacter sp.
Match the following disease states with the corresponding organism.
Watery (rice-water) diarrhea
Vibrio cholerae
Match the following disease states with the corresponding organism.
Most Urinary Tract Infections (90%)
E. coli
Serotyping of O, H, or K antigens WOULD NOT be necessary in the final identification of this organism:
Citrobacter sp.
Intrinsic resistance to numerous antibiotics is associated with this lactose negative organism.
Pseudomonas aeruginosa
An organism was isolated from the sputum of a patient with a chronic cough. It is very mucoid and a lactose fermenter. It is H2S negative, indole negative and VP positive. The organism is most likely:
Klebsiella pneumoniae
This organism is H2S negative, oxidase negative, NLF on MacConkey and may produce a slight ammonia odor:
Stenotrophomas maltophilia
All of these disease states are associated with Salmonella infections except: Bacteremia Hemolytic Uremic Syndrome Gastroenteritis Enteric fever
Hemolytic Uremic Syndrome
The citrate utilization test, demonstrates the ability of an organism:
To use sodium citrate as its only carbon source
Y. enterocolitica produces a characteristic “dark red bulls eye colony” on this selective agar.
CIN
Which organism is not commonly associated with nosocomial infections
Pasteurella multocida
True or False?
Vibrio cholerae produce a virulent toxin-mediated disease
True
This oxidase negative organism is highly resistant, opportunistic and a common colonizer of hospitalized patients
Acinetobacter spp.
What organism is most likely on TCBS agar.
Vibrio cholerae
A gram neg rod was isolated from the skin of a 56 y/o male hospitalized patient with 2nd degree burns. The following results were observed.
Good growth on Blood, chocolate, and MacCOnkey
MacConky - clear/colorless colonies
Cetrimide agar - growth - blue/green pigment
oxidase - positive
Growth @ 42 degrees C
A grapelike odor was observed. The organism exhibited multiple antibiotic resistance. What is the most likely organism?
Pseudomonas aeruginosa
A 25 y/o woman presents to her physician with what appears to be a UTI. The urine is cultured with the following results: blood - large gray moist colonies PEA - no growth MacConky - pink, flat colonis TSI - A/A no H2S Oxidase - negative Indole positive, citrate negative What is causing her UTI?
E. coli
A 60 year old male is seen in the ER for chronic diarrhea of 5 day duration. A stool culture is performed with the following results.
Blood - growth, gray colonies with distinct margins
Mac - growth, clear colonies
HE - clear colonies with black center
Citrate - positive
Motility - positive
Indole - negative
TSI - K/A w/H2S
What is the most likely etiological agent?
Salmonella enteritidis
A 24 year old male was seen by his physician for a swollen finger with a open wound. He thinks the injury may have occurred while he was participating in the “UFC” match 2 weeks ago. A culture was taken. After cleaning and dressing the wound he was given a course of antibiotics. A culture of the abscess was performed with the following results:
Gram stain - gram neg rods
Growth on blood and chocolate after 48 hours. The organism appears to be pitting the agar
MacConkey - no growth
oxidase - positive
catalase - negative
indole - negative
The micro tech noticed a sharp odor of bleach when he opened the plate.
Which organism is the most likely cause of the infection?
Eikenella corrodens
An organism was isolated from the urine of a hospitalized 56 y/o male. The following results were observed at 24 hrs.
Blood - growth, smooth, raised, creamy colonies
PEA - no growth
Growth on MacConkey - clear colonies with a slight purple color
oxidase - neg
gram stain - gram neg rod
What is the most likely cause of infection?
Acinetobacter spp.
A five year old boy has a leg wound that has not responded to treatment at home. His pediatrician cultures the wound and prescribes penicillin. The boy's mother explains that he very often has scratches after playing with his dog, a german shephard. The wound has healed following the prescribed treatment. The subsequent 24 hour culture results reveal: Growth on Blood and Chocolate in CO2 MacConkey - no growth Gram stain - short gram negative rods catalase - pos oxidase - pos non motile indole positive
Pasteurella multocida
A patient is seen in the emergency dept complaining of a fever and a red, swollen mass on his right leg. He has just returned from a July 4th boat trip in the Chesapeake Bay. The wound was cultured with the following:
Growth on blood and choc - large, smooth colonies
MacConkey - light pink
gram stain - gram neg rods, slightly curved
catalase - pos
oxidase - pos
Growth on TCBS - green colonies
An API was performed. What is the most likely ID?
Vibrio vulnificus
An organism was isolated from the blood of a 40 year old male in acute respiratory distress. His medical history indicated that he had just returned from a mission trip to tropical areas of Thailand. His respiratory cultures grew the following:
Clear colonies on Mac
Growth on blood and chocolate
Oxidase - positive
gram stain - bipolar staining gram neg rods (resembling safety pins)
Special precautions were taken when handling this organism. What is the suspected organism?
Burholderia pseudomallei
A 35 year old man has returned from a camping trip in New Mexico. He has a fever and swollen lymph nodes. Cultures reveal:
Blood agar - pinpoint @ 24 hours, cauliflower @ 48
Mac - NLF, colorless to peach
HE - salmon colonies
XLD - yellow colonies
API was performed as well as serotyping
*Patient history indicated the patient slept in a tent and noticed numerous fleas in the area. What is the most likely ID?
Yersinia pestis
What organism produces a bright red pigment on MacConkey?
Serratia marcescens
