Micro 6 - Intro To Gram Negative Bacteria Flashcards
Which G(-) cocci is a maltose fermenter?
N.meningitids.
Which G(-) cocci is a maltose nonfermenter?
N.gonorrhoeae.
What are 4 important Coccoid Rods?
H.influenzae, B.pertussis, Pasteurella, Brucella.
Which three G(-) rods are fast lactose fermenters?
Klebsiella, E.coli, Enterobacter.
Which two G(-) rods are lactose slow fermenter?
Citrobacter, Serratia, Others.
Which three G(-) rods are lactose nonfermenter and oxidase negative?
Shigella, Salmonella, Proteus.
Which G(-) rod is a lactose nonfermenter and oxidase positive?
Pseudomonas.
Which G(-) bacteria that is oxidase positive has a curved shape grows in 42C?
Campylobacter jejuni (helical or Z shaped).
Which G(-) bacteria that is oxidase positive has a curved shape and grows in alkaline media?
Vibrio cholerae (comma-shaped).
What are three important G(-) Cocci?
N.meningitidis, N.gonorrhoeae, Moraxella catarrhalis.
What are three descriptions of Neisseria species?
G(-) diplococci, ferment glucose, IgA protease.
What can Neisseria Gonococci cause?
Urethritis, PID, STI, Septic arthritis, conjunctivitis (newborns thru the birth canal).
What are two descriptions of Neiseeria Gonococci?
Maltose non-fermenter, No polysaccharide capsule.
What is the first line treatment for Neisseria Gonococci? Second line?
First line is Ceftriaxone. Second line is Azithromycin.
What is the mode of transmission of Neisseria meningococci that Neisseria gonococci does not have?
N.meningococci can be transmitted by respiratory secretions. N.gonococci is transmitted sexually or by birth canal.
What syndrome can N.meningococci cause?
Waterhouse-Friderichsen syndrome (adrenal hemorrhage).
What is the treatment for Neisseria Meningococci?
Ceftriaxone. Penicllin G only if it is confirmed by culture and sensitivity confirmation that it is going to work.
What is the prophylaxis treatment for Neisseria Meningococci?
Rifampin, ciprofloxacin, or ceftriaxone. You do not wait for culture results.
What type of bacteria is Haemophilus influenzae?
G(-) coccoid rod or coccobacilli.
What disease can Haemophilus influenzae cause?
Epiglottitis (in children, it can cause the “sniffing dog” position, because they are trying to open their airway to breath better, “thumbs up” on Xray), meningitis, otitis media, sinusitis, pneumonia.
How can we culture Haemophilus Influenzae?
Chocolate agar with factor V and X.
What is the treatment for Haemophilus influenzae?
Ceftriaxone.
What is the prophylaxis treatment for Haemophilus influenzae?
Rifampin.
What does Haemophilus ducreyi cause?
Causes a chancroid, a genital ulcer that is painful and solitary.
What type of bacteria is Legionella pneumophila?
G(-) rod but stains very poorly so a silver stain is needed.
What is needed to culture Legionella pneumophila?
You need a charcoal and yeast extract with iron and cystine. [French Legionare with a silver helmet, with a charcoal fire, has an iron dagger and he is no sissy].
What is the treatment for Legionella pneumophila?
Erythromycin or other macrolides.
What disease does Legionella pneumophila cause?
Legionnaires’ disease, a severe pneumonia with fever. Or it can cause Pontiac fever, a flu-like disease.
What is the infection route of Legionella pneumophila?
It is transmitted in aerosol transmission from a body of water (airconditioner infected in an old barracks). There is no person-to-person transmission.
How can we diagnose Legionella pneumophila?
Presence of antigen in the urine.
What are four descriptions of Pseudomonas aeruginosa?
G(-) rod, oxidase positive and lactose non-fermenter. Causes a blue-green pigment.
What type of environment does pseudomonas aeruginosa love?
Moist environments (Hot tub folliculitis). Contaminates medical equipment and catheters and burn victims.
What diseases does Pseudomonas aeruginosa cause?
Pneumonia (cystic fibrosis), otitis externa, UTIs, Osteomyelitis (diabetics), sepsis.
What toxin does Pseudomonas aeruginosa produce and what is it’s mechanism?
Exotoxin-A and it inactivates EF-2 causing cell necrosis.
What is the treatment for Pseudomonas aeruginosa?
It depends on the site of infection. Since it is a dangerous bacteria it needs to antibiotics: piperacillin and ticarcillin; cefepime and ceftazidime; imipenem, meropenem, fluoroquinolones.
What is the cause of more than 90% of duodenal ulcers?
Helicobacter pylori.
What are three descriptions of Helicobater pylori?
G(-) rod, Urease positive, has a helical or Z shape.
How can we diagnose Helicobater pylori?
Urea breath test, stool antigens and serology studies.
What is the treatment for Helicobacter pylori?
Triple therapy: PPI, clarithromycin, and amoxicillin or metronidazole (If someone is penicillin allergic). Quadruple therapy: Bismuth, metronidazole, PPI, Tetracycline.
A culture reveals a G(-), oxidase (+), diplococci. What bacteria might you suspect?
Neisseria gonorrhoeae or Neisseria meningitidis.
A 22yo medical student has burning feeling in his abdomen after a meals and EGD is performed and biopsy reveals spiral shaped G(-) bacteria. What is the diagnosis?
Helicobacter pylori.
A 50yo smoker presents with a new cough and flu like symptoms. Gram stain of the sputum reveals shows no organisms but silver stain shows rods. What is the disease and bacteria that is causing this?
Pontiac fever by Legionella pneumophila.
What G(-) causes sepsis, DIC, and adrenal hemorrhage?
It is Waterhouse-Friderichsen syndrome caused by N.meningitids.
What G(-) causes a 5yo w/ pharyngitis, drooling, and X-ray reveals thumb sign?
Epiglotittis caused by Haemophilus Influenza type B.
What G(-) would cause a burn wound infection?
Pseudomonas.
What G(-) causes life-threatning meningitis + purpura?
Neisseria meningitidis.
What G(-) would cause septic arthritis in young, sexually active patients?
Neisseria gonorrhoeae.
