Gastrointestinal Cultures Flashcards
Obj. 1: Outline the path food takes through the anatomical regions of the gastrointestinal tract
Mouth — Esophagus — Stomach — Small Intestine — Large Intestine — Rectum — Anus
Obj. 2: Recognize mechanisms present in the host that help to prevent infection
- Acidic environment of the stomach
- Peristalsis of small intestines
- Secretion of IgA in small intestines and colon
- Normal gut microbiota
Obj. 3: Identify members of the normal adult bowel flora
- Enterobacterales (i.e. E. coli, Kleb., Enterobacter, etc.)
- Enterococcus
- Streptococcus (Grp. D)
- Bacteroides fragilis grp.
- Fusobacterium spp.
- Clostridium spp.
- Peptostreptococcus anaerobius (anaerobic cocci)
Obj. 4: List the clinical signs of dehydration
- Sunken appearance to the eyes
- Dry Oral Membranes
- Loss of skin resiliency
- Decrease in blood pressure
- Mental confusion
- Tachycardia
Obj. 6: Differentiate between infections and intoxications based on symptoms and timing of onset
Infections
- Symptoms: Fever
- Timing: 1-3 days
Intoxications
- Symptoms: No fever
- Timing: within hours
Obj. 7: Recognize the organisms that are responsible for intoxications rather than infections
- S. aureus
- B. cereus
- C. perfringens
- C. botulinum
Obj. 9: Identify the transport medium recommended for stool specimens, especially for culture of Vibrio species
Modified Cary-Blair
Obj. 12: List the stool pathogens that must be serologically typed after they are identified in the laboratory
- Shigella
- Salmonella
- E. coli O157:H7
Obj. 13: Discuss the procedure and rational for typing the above pathogens
To confirm ID of isolate and for epidemiologic tracking
Obj. 10: Select appropriate media and incubation conditions for culture of the clinically significant, bacterial, enteric pathogens#:
- Vibrio cholerae
Obj. 11: Recognize the appearance of these pathogens# on the above media (if appropriate)
TCBS agar (selective for GNRs, differential for sucrose utilization)
CHO+ (yellow colonies)
(SBA agar: oxidase positive)
Incubation: Ambient Air
Obj. 10: Select appropriate media and incubation conditions for culture of the clinically significant, bacterial, enteric pathogens#:
- Vibrio parahaemolyticus
Obj. 11: Recognize the appearance of these pathogens# on the above media (if appropriate)
TCBS agar (selective for GNRs, differential for sucrose utilization)
CHO = (green colonies)
(SBA agar: oxidase positive)
Incubation: Ambient Air
Obj. 10: Select appropriate media and incubation conditions for culture of the clinically significant, bacterial, enteric pathogens#:
- Vibrio vulnificus
Obj. 11: Recognize the appearance of these pathogens# on the above media (if appropriate)
TCBS agar (selective for GNRs, differential for sucrose utilization)
CHO = (green colonies)
MAC: Some are lactose + (pink colonies)
(SBA agar: oxidase positive)
Incubation: Ambient Air
Obj. 18: Identify clinically significant, bacterial, enteric pathogens# when given biochemical results
- Vibrio spp.
String Test +
Vibrostatic 0/129: Susceptible
Obj. 19: Recognize the Gram stain morphology of isolated clinically significant, bacterial, enteric pathogens*#
Vibrio spp.
Obj. 10: Select appropriate media and incubation conditions for culture of the clinically significant, bacterial, enteric pathogens#:
- Shigella
Obj. 11: Recognize the appearance of these pathogens# on the above media (if appropriate)
MAC: lactose = (clear colonies)
HEK/XLD: lactose & “other” sugars = (green/red colonies)
Incubation: Ambient Air
Obj. 18: Identify clinically significant, bacterial, enteric pathogens# when given biochemical results
- Shigella
Phenylalanine =, Urease =, H2S =
IMVICU (++—- or -+—-), lactose =, lysine =, motility =
Serotyping required to confirm ID
Obj. 10: Select appropriate media and incubation conditions for culture of the clinically significant, bacterial, enteric pathogens#:
- E. coli (O157:H7)
Obj. 11: Recognize the appearance of these pathogens# on the above media (if appropriate)
SMAC (selective for GNRs, differential for sorbitol utilization)
Sorbitol = (clear colonies)
Incubation: Ambient Air
Obj. 18: Identify clinically significant, bacterial, enteric pathogens# when given biochemical results
- E. coli (O157:H7)
Phenylalanine =, Urease =, H2S =
IMVICU (++—- ), lactose +/=, lysine +/=, motility +/=
(MUG =)
Serotyping required to confirm ID
Obj. 10: Select appropriate media and incubation conditions for culture of the clinically significant, bacterial, enteric pathogens#:
- Salmonella
Obj. 11: Recognize the appearance of these pathogens# on the above media (if appropriate)
MAC: lactose = (clear colonies)
HEK/XLD: lactose & “other” sugars = (black/black colonies)
Incubation: Ambient Air
Obj. 18: Identify clinically significant, bacterial, enteric pathogens# when given biochemical results
- Salmonella
Phenylalanine =, Urease =, H2S +
Lactose =, Citrate +, Lysine +
Serotyping required to confirm ID
Obj. 10: Select appropriate media and incubation conditions for culture of the clinically significant, bacterial, enteric pathogens#:
- Listeria
Obj. 11: Recognize the appearance of these pathogens# on the above media (if appropriate)
SBA
Incubation: CO2
Resembles Beta Strep
Obj. 18: Identify clinically significant, bacterial, enteric pathogens# when given biochemical results
- Listeria
Catalase +, Umbrella motility at 25 deg., Bile Esculin +
Obj. 19: Recognize the Gram stain morphology of isolated clinically significant, bacterial, enteric pathogens*#
Listeria spp.
Obj. 10: Select appropriate media and incubation conditions for culture of the clinically significant, bacterial, enteric pathogens#:
- Yersinia enterolitica and pseudotuberculosis
MAC/CIN/YSA at 22-28 deg.