Gram Negative Rods 3 Flashcards
Comma-shaped rod bacteria with
monotrichous flagellation
Vebrio cholera
On MacConkeys agar it shows colorless colonies.
• Growth is favored by alkaline pH (8-9.6).
• It grows on alkaline peptone water, forming a surface pellicle.
• On thiosulphate citrate bile sucrose agar (TCBS), it produces yellow
colonies.
Vebrio cholera
What starin of vebrio cholera is responsible for epidemics cholera?
O139
degrades the mucous layer covering the intestinal cells.
Mucisnase
Sudden onset of severe vomiting, rice
watery diarrhea with abdominal cramps. Diarrhea is severe; the patient
may lose up to 20 liters fluid per day. • Complications include: dehydration, hypokalemia, metabolic acidosis,
shock and death.
Cholera caused by vibrio cholera
You’re on a summer program working in a clinic in a small village in Ecuador. There is an outbreak of cholera, and your patient has massive diarrhea and a blood pressure of 70/40. Which one of the following would be the most appropriate action to take?
(A) Administer antimotility drugs to diminish the diarrhea.
(B) Administer intravenous saline to replenish volume.
(C) Administer tetracycline to kill the organism.
(D) Perform stool cultures and fecal leukocyte tests to make an accurate diagnosis.
Administer intravenous saline to replenish volume.
Your patient is a 20-year-old woman with diarrhea. She has just returned to the United States from a 3-week trip to Peru, where she ate some raw shellfish at the farewell party. She now has severe watery diarrhea, perhaps 20 bowel movements a day, and is feeling quite weak and dizzy. Her stool is guaiac-negative, a test that determines whether there is blood in the stool. A Gram stain of the stool reveals curved gram-negative rods. Culture of the stool on MacConkey’s agar shows colorless colonies. Which one of the following bacteria is the most likely cause of this infection?
(A) Escherichia coli
(B) Helicobacter pylori
(C) Proteus mirabilis
(D) Pseudomonas aeruginosa
(E) Vibrio cholerae
Vibrio cholerae
P. aeruginosacolonies producing exo- pigments giving ?
Green color on nutrients agar
Pyocynin blue
Florucent yellow
P. Aeurginosa virulance that mediate adherence to mucus
membrane & biofilm formation.
Exopolysaccharide (glycocalyx) slime
Primarily a nosocomial pathogen.
P.aeruginosa
A 21-year-old man is traveling in rural India. Over the course of a few hours, he develops severe watery diarrhea. In the next 30 hours, he has approximately one episode per hour of liquid stools that appear clear with small white flecks of mucus. (rice water stool)
1-What is the name of the medium used to isolate the causative organism
TCPS media giving yellowish color
A 21-year-old man is traveling in rural India. Over the course of a few hours, he develops severe watery diarrhea. In the next 30 hours, he has approximately one episode per hour of liquid stools that appear clear with small white flecks of mucus. (rice water stool)
2-What is the causative organism
Vibrio cholera
A 27-year-old male was hospitalized suffering from third degree burns over 50% of his body from a house fire. After 6 days in the hospital, he becomes septic and the burn wounds show tissue necrosis in several areas. Blood and wound cultures grew Gram-negative bacillus resistant to, macrolides, and first-generation and second-generation cephalosporins. The organism growing on nutrient agar in green color .
1-What is the etiology of this man’s burn infection?
Psedunomas aeruginosa
A 27-year-old male was hospitalized suffering from third degree burns over 50% of his body from a house fire. After 6 days in the hospital, he becomes septic and the burn wounds show tissue necrosis in several areas. Blood and wound cultures grew Gram-negative bacillus resistant to, macrolides, and first-generation and second-generation cephalosporins. The organism growing on nutrient agar in green .
2-This organism is oxidase( –ve—–+ve)
Negative
Your patient has third-degree burns over most of his body. He was doing well until 2 days ago, when he spiked a fever, and his dressings revealed pus that had a blue-green color. Gram stain of the pus revealed a gram-negative rod that formed colorless colonies on EMB agar. Which one of the following bacteria is the most likely cause of this infection?
(A) Campylobacter jejuni
(B) Escherichia coli
(C) Haemophilus influenzae
(D) Pseudomonas aeruginosa
(E) Salmonella enterica
Pseudomonas aeruginosa
