Non-fermentative Gram Neg Bacilli Glucose Oxidizers Flashcards
Under what condition do these organisms grow?
Obligate aerobe
Most of these organisms are oxidase positive. Which are not?
Acinetobacter and Stenoteophomonas
What is the most common isolated glucose non-fermenter clinically?
Pseudomonas aeruginosa (rarely normal flora)
What is the key pathogen found in patients with cystic fibrosis?
Pseudomonas aeruginosa
What is another organism that causes cystic fibrosis?
Burkholderia cepacia
causes glanders in horses, mules, etc.
Burkholderia mallei
found in soil and rice paddies
Burkholderia pseudomallei
this organism is found in hospitalized patients and is the 2nd most common glucose non-fermenter isolated clinically.
Acinetobacter spp.
found in respiratory tract of hospital patients and is the 3rd most common glucose non-fermenter isolated clinically.
Stenotrophomonas maltophilia
Pseudomonas aeruginosa general info
Glucose oxidizer. oxidase pos. MAC pos. serrated edges and green pigment and metallic sheen. common cause of nosomial infections. TSI Slant- K/K, gas Neg, H2S Neg.
list the virulence factors of pseudomonas aeruginosa.
exotoxin A, Alginate, Pyocyanin, Pili, and intrinsic resistance to antimicrobials.
Exotoxin A inhibits what?
protein synthesis in host cells
what does alginate do?
surface carb that impedes phagocytosis.
What does pyocyanin do?
blue pigment produces reactive oxygen species causing tissue damage.
What is Pili used for?
for attachment to host cells.
list Pseudomonas pigments.
Pyocyanin-blue green (only produced by P. aeruginosa), Pyoverdin- yellow (visualize with UV light), Pyorubin- rust, and Pyomelanin- brown.
what is pseudomonas aeruginosa resistant to?
penicillin and ampicillin
what is pseudomonas aeruginosa susceptible to?
aminoglycosides, extended spectrum penicillins, carbapenems, and quinolones.
what is the most common pathogen for CF in the 1st decade of life?
Staph aureus and Haemophilus influenzae
how is burkholderia cepacia spread?
kissing and doorknobs. able to survive on or in medical devices and disinfectants.
general info for burkholderia cepacia.
oxidase pos. LDC pos. Polymyxin B resistance.
what is media used to help isolate in CF patients.
OFBL and PC
general info for burkholderia mallei
MAC pos. Oxidase pos.
what do you treat glanders with?
tetracyclines
how does glanders transmit?
NO human to human transmission. Contract via cuts and contact with horse tissues/ fluids.
general info burkholderia pseudomallei
MAC pos. oxidase pos.
how is burkholderia pseudomallei transmitted?
inhalation or inoculation through cuts
which organism is the causative agent of Melioidosis (Whitmore’s disease)?
burkholderia pseudomallei
what is the treatment for melioidosis (Whitmore’s disease)?
oral antibiotics (deoxycycline) or intravenous (ceftazidime).
general info for Acinetobacter spp.
Oxidase pos. catalase pos. doesn’t reduce nitrates to nitrites (P. aeruginosa does). can create a purple hue on MAC though they’re NOT lactose fermenters. resistant to many antibiotics.
general info for Stenoteophomonas maltophilia.
Strong maltose oxidizer. glucose oxidizer. oxidease NEG. MAC pos. arginine neg. ornithine neg. lysine pos. dnase pos. polymyxin B sensitive.
Why do anaerobic organisms use the EMP pathway?
EMP yields more ATP than ED pathway (2 ATP/Glucose)
what pathway is seen in more aerobic organisms?
ED pathway
why do some organisms use the ED pathway?
ED pathway requires less enzymatic protein to carry out glucose metabolism.
what kind of reaction is fermentation?
oxidation-reduction (oxygen is excluded)
what reaction does weak acid is formed and no gas produced?
oxidation/oxidative
what is the definition of oxidation?
any process in which the oxygen content of a compound is increased; any reaction in which the positive valence of a compound or a radical is increased because of a loss of electrons.
what does oxidative of tubes look like?
acid in open tube only
