Exam 3 (Non-Fermentive Gram- Bacilli....Glucose Oxidizers) Flashcards
Glucose is the major carbohydrate used by bacteria as a source of what:
Carbon, for cellular respiration
How is glucose used by bacteria as a carbon source for cellular respiration:
The energy released from the chemical bonds in glucose is used to produce ATP
Glucose can be metabolized to pyruvate via how many ways:
3 pathways (glycolysis)
What two glycolytic pathways are we focused on in this unit:
EMP
ED
T/F
EMP is found in both eukaryotes and prokaryotes:
True
Which pathway yields more ATP, EMP or ED?
EMP (2 ATP per 1 glucose)
Which glycolytic pathway is preferred by anaerobic bacteria and why:
EMP, it yields more ATP per glucose
Which glycolytic pathway is more commonly used by aerobic bacteria and why:
ED, requires less enzymatic protein to carry out glucose metabolism
Fermentation is synonymous with:
Anaerobic metabolism
Fermentation results from this type of reaction:
Oxidation-Reduction
Can fermentation occur in the presence of oxygen:
Yes, it just does not require it
These 3 things are produced from fermentation:
Mixed acid products
Alcohols
Gases
Fermentation is detected via _____ in the lab:
pH changes (color indicators)
This is defined as any process in which 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:
Aerobic Metabolism (oxidation)
Oxidation is synonymous with _______ metabolism:
aerobic
Oxidation results in what for acid formation and gas production:
- weak acids formed
* no gas produced
T/F
Oxidation (aerobic metabolism) requires more sensitive detection systems:
True
This media is used to determine if Gram- bacteria metabolize carbohydrates oxidatively, by fermentation, or are asaccharolytic:
Hugh-Leifson OF media
What are bacteria called that have no ability to use carbohydrates:
asaccharolytic
Why does OF media have a decreased peptone concentration:
The decreased concentration minimizes formation of alkaline amines, which can mask small amounts of acid produced in oxidative (aerobic) metabolism.
OF media has ____ peptones, ______ carbohydrates, and uses_____ as its color pH indicator:
- Decreased peptones
- Increased carbohydrates
- Bromthymol blue (blue/green–> yellow)
OF media testing requires ____ tubes, one that is ____ and one that is _____:
2 tubes
- one open, loosely capped
- one closed, mineral oil + tightly capped
OF media, yellow only in ‘open’ tube:
oxidative
OF media, yellow in both tubes:
fermentation OR
both fermentation/oxidation
OF media, no color change in either tube:
Asaccharolytic
What tube reaction(s) would you expect with OF media in an oxidative organism:
Color (pH) change in ‘open’ tube only
Non-fermentive Gram- bacilli (glucose oxidizers) grow on these 3 agars:
SBAP
CAP
MacConkey (clear colonies)
Are all non-fermentive Gram- bacilli glucose oxidizers?
No. Some are asaccharolytic
What is the optimal incubation temp and time for non-fermentive Gram- bacilli glucose oxidizers:
22-35 C
24-72 hours
Most non–fermentive Gram- bacilli glucose oxidizers are obligate ______:
aerobes
Should you do a Gram stain from MacConkey:
no
only SBAP or CAP
List the organisms of the non-fermentive Gram- bacilli group:
Pseudomonas aeruginosa Burkholderia cepacia Burkholderia mallei Burkholderia pseudomallei Acinetobacter spp. Stenotrophomonas maltophilia
which two organisms are oxidase positive:
Pseudomonas
Burkolderia
Which two organisms are oxidase negative:
Acinetobacter
Stenotrophomonas
This organism can have mucoid and non-mucoid strains:
Pseudomonas aeruginosa
Mucoid strains of Pseuodomas incubate ____, non-mucoid strains need up to ____ for growth:
Mucoid: 24 hour
Non-mucoid: up to 7 days for growth
This organism has a flat spreading appearance on SBAP with serrated edges and green pigment and metallic sheen:
Pseudomonas aeruginosa
Pseudomonas aeruginosa, Glucose: Oxidase: MAC: motility: Incubation temp: Odor: Nosocomial:
Glucose: oxidizer Oxidase: + MAC: + (w/ clear colonies) motility: Motile, polar flagella Incubation temp: 42 C Odor: grape/corn tortilla Nosocomial: common cause
List the 4 virulence factors for P. aeruginosa:
- Exotoxin A
- Alginate
- Pyocyanin
- pili
This virulence factor of Pseudomonas inhibits protein synthesis in host cells:
Exotoxin A
This virulence factor of Pseudomonas is a surface carb that impedes phagocytosis:
Alginate
This virulence factor of Pseudomonas is a blue pigment that produces reactive oxygen species causing tissue damage:
Pyocyanin
How do pili increase virulence of Pseudomonas:
All for better attachment to host cells
What contributes to greenish color on SBAP with Pseudomonas:
Pyocyanin
Does all Pseudomonas produce pyocyanin?
No. About 4% do not.
List the 4 pigments associated with Pseudomonas:
Pyocyanin (blue/green)
Pyoverdin (yellow fluorescein)
Pyorubin (red)
Pyomelanin (brown)
This pigment helps the bacteria obtain iron from the environment, important for its’ metabolism:
Pyoverdin
This pigment helps microbes better survive oxidative stress, promoting survival in lungs:
Pyomelanin
Pseudomonas aeruginosa is resistant to —– and susceptible to::
R: Penicillin and Ampicillin
S: Aminoglycosides, carbapenems, quinolones, extended spectrum penicillins
T/F
Burholderia cepacia complex is resistant to Colistin:
True
This is the most common cause of lung infection in CF patients in third decade of life:
Pseudomonas aeruginosa
Which two organisms are the most common cause of lung infection in CF patients in first decade of life:
Staph aureus
Haemophilus influenzae
T/F
Burkholderia cepacia can spread person to person and can survive on medical devices:
True.
Pseudomonas aeruginosa is resistant to ____ and ____:
Penicillin
Ampicillin
Is Pseudomonas aeruginosa normal flora?
Rarely
Is Burkolderia cepacia normal flora?
No
OFPBL and PC media is used to isolate this bacterium in CF patients:
Burkholderia cepacia
What does OFPBL stand for:
Oxidate-fermentive base-polymyxin B-bacitracin-lactose agar
Is Burkholderia cepacia resistant or susceptible to polymyxin b?
resistant
which is rare for GNR
Bartlett’s Screening method of sputum samples involves counting these two things in low power field:
Epithelial cells
Neutrophils
What score is required with Bartlett’s screening method for sputum in order to be worked up, what score would be rejected:
1 or above = work up
0 or less = reject
MAC+, Oxidase+ cause of Glanders in horses:
Burkholderia mallei
Glanders is treated with:
Tetracyclines
MAC+ Oxidase+ found in soil, streams, rice paddies:
Burkholderia pseudomallei
What is the disease caused by Burkholderia pseudomallei:
Melioidosis
aka Whitmore’s Disease
Melioidosis is also known as ______, is caused by the bacterium ______, and is found in _______:
Whitmore’s disease
Burkholderia pseudomallei
SE Asia
This is the 2nd most common glucose non-fermenter isolated in clinical labs:
Acinetobacter
Acinetobacter is normal flora of _____ and _____:
skin
vaginal tract
T/F
Acinetobacter is a cause of nosocomial infections via ventilators, humidifiers, catheters:
True
Are all Acinetobactor spp. glucose oxidizers:
No. Some are asaccharolytic
Gram negative rods, plump, often in pairs, oxidase neg, catalase pos, non-motile, does not reduce nitrates:
Acinetobacter
Is Acinetobacter resistant to any antibiotics:
yes, many
This organism is a strong maltose oxidizer and is the 3rd most common glucose non-fermenter encountered clinically:
Stenotrophomonas maltophilia
What do colonies of Stenotrophomonas maltophilia look like on SBAP:
pale yellow to lavender pigment
What is the drug of choice for Stenotrophomonas maltophilia:
trimethoprim-sulfamethoxazole
