Examination 3: Gram negative bacilli, fermentation, antibiotics Flashcards
- Only _____ % of people with Helicobacter pylori develop a peptic ulcer
- Glucose can be _____ by Vibrio.
- 10 - 20%
- Fermented
- Inhibitors of cell wall synthesis kill bacteria by _____.
- Vibrio, Aeromonas, and Chromobacterium are/are not normal flora. What are their O2 requirements?
- inhibited production of murein/peptidoglycan layer
- Are not / Facultative anaerobes
This agar is buffered to prevent pH changes.
Complications of peptic ulcer disease
Mueller-Hinton agar
Hemorrhage (anemia)
Complications of peptic ulcer disease
Hemorrhage (anemia)
Burkholderia mallei causes _____ in horses.
Glanders
_____ is typically not used for Campylobacter
Serodiagnosis
Antibiotics for other spp of Vibrio (besides cholerae) _____.
are not standardized
The mechanism of this antibiotic is not known but it only works within the urinary tract.
Nitrofurantoin
Sulfonamides are prescribed as a treatment for _____.
UTIs
Oxidase testing of Vibrio should only be done _____.
off SBAP or one w/o a fermentable sugar
Synergistic
When the result of 2 drugs is greater than the response of them separately
If Kirby-Bauer plates are too thin, this results in _____.
(2 Factors)
Larger zones of inhibition
False susceptibility
If an organism is resistant to an antibiotic the treatment is considered to be _____.
Not effective.
Helicobacter pylori buffers its immediate vicinity from HCl by _____.
producing ammonia and CO2 from endogenous urea
Chloramphenicol, Erythromycin, and Sulfa drugs may be indicated for the treatment of _____ due to the development of resistance to tetracycline and doxycycline.
Vibrio cholerae
Two antibiotics of cell membrane function are
Polymyxin B
Colistin
The Schlichter test is also known as _____.
Serum bacteriocidal test
How are B mallei and pseudomallei differentiated?
Definitive ID is often done in reference labs with additional biochemical tests.
What is a contraindication for aminoglycoside regimens and what should the patient avoid?
Contraindicated for renal patients.
Patient should avoid the use of NSAIDs.
Oxidase negative non-fermentative GNB (2)
Acinetobacter, Stenotrophomonas
How would a pH increase affect aminoglycoside activity?
It would decrease tetracycline activity.
2nd most common GNF isolated in clinical labs
Acinetobacter spp
Antibiotics can inhibit _____ , _____ , or _____ synthesis.
Cell wall
Protein
DNA/RNA
Achromobacter and Chryseobacterium are MacConkey _____ and Oxidase _____.
Positive/Positive
Kirby-Bauer susceptibility testing cultures should ideally be performed when the culture is _____. If it is too old this leads the cultures to be _____.
24 hours old
Non-viable and can lead to false susceptibilities
Macrolides and Chloramphenicol are _____.
Polymixins are NSAs that are most effective against _____.
Bacteriostatic inhibitors of protein synthesis
G- bacteria
V/A/C preferred habitat
Water
Helicobacter is ideally recovered on what two media?
Chocolate
Brucella
Environmentally mediated resistance
Results from physical/chemical characteristics of the environment
Meliodosis is known to occur in what geographical locale
Southeast Asia
Enzymes that mediate resistance to Beta Lactams
(5)
Penicillinases
Cephalosporinases
ESBL’s
Cephamycinases
Carbapenemases
Gram stain Vibrio
G- bacteria, straight to slightly curved rods
Infections of Alcaligenes and Bordetella are found more commonly in _____.
Commercial ID methods of these two are _____.
Immunosuppressed
Limited
This antibiotic is effective against G+, G-, and intracellular bacterial pathogens
Tetracycline
The E-test is a form of _____ susceptibility testing.
Quantitative
Pseudomonas has a net _____ charge.
Negative
Non-fermentive G- bacilli typically _____ on MacConkey agar.
grow
Acinetobacter is MAC _____ and oxidase _____.
Positive, Negative
This antibiotic type binds precursors of cell wall synthesis.
Glycopeptides
Rat bite fever symptoms include _____ (3).
Lymphadenitis
Rash
Flu-like symptoms
Also: relapsing fever, chills, systemic illness such as arthritis, meningitis, liver and spleen disease
Most common method of bacterial resistance to penicillins
Beta-lactamase
What are 01 and 0139, hemolysins, cytotoxins, and pili?
Virulence factors of Vibrio cholerae
Enterobacteriacea is MAC _____ and oxidase _____.
Positive, Negative
How are Kirby Bauer results reported?
Only as susceptible, resistant, or intermediate – NOT diameters.
Where should disks not be placed when performing a Kirby-Bauer sensitivity test?
Towards the edges of the plate.
Is Burkholderia mucoid or non-mucoid?
Non-mucoid
Glycopeptides and Bacitracin are _____.
NSAs effective against G+ bacteria
Cholera patients present with this particular kind of stool.
Rice water
How should Kirby Bauer disk-diffusion plates be incubated?
(Temperature, O2 conditions, Position)
35 degrees C
CO2, if required
Inverted
Mueller-Hinton agar is _____ to prevent _____.
Buffered
pH change
Environmentally, where is Alcaligenes found?
Soil, Water
Helicobacter pylori possible routes of transmission
Oral/Oral
Fecal/Oral
What is MBC?
Minimal Bactericidal Concentration. Minimum [] at which the bacterial population is killed
The folic acid pathway produces _____.
(Besides folic acid)
Precursors for DNA synthesis.
What is important to know about NSAIDs
Should not be used with aminoglycosides.
Chryseobacterium can survive in _____ environments, especially moist environments where _____ is present.
Hospital environments
Chlorinated water
NSAs effective against G- bacteria
Polymixins
Streptobacillus moniliformis grows on _____ with _____ and _____.
SBAP
Increased CO2
Humid environment
In humans Glanders can cause _____ (3).
Localized, pulmonary, and bloodstream infections
How do inhibitors of protein synthesis interfere with normal cell function?
(3 ways)
- Interrupt initial formation of proteins.
- Interferes with accurate reading of mRNA code.
- Disrupts ribosomal-mRNA complex
What antibiotic should be monitored carefully in terms of bone marrow aplasia?
Chloramphenicol
VRSA emerged from the exchange of genetic material from _____ to _____.
VRE to MRSA
Most GNF are oxidase positive except _____ and _____.
Acinetobacter Stenotrophomonas
[Alcaligenes / Bordetella] does not grow well.
Pick one of the two.
Bordetella
P aeruginosa has a _____ flagella
Monotrichous polar
Susceptibility testing for Campylobacter is typically not _____.
Standardized
Metronidazole is an inhibitor of _____.
DNA/RNA synthesis.
Mueller-Hinton agar supports the growth of _____.
Most frequent isolates
Kingella spp. (2)
K. kingae and K. denitrificans
When would an MIC be an appropriate test?
In use of penicillins or cephalosporins for S. pneumoniae treatments.
This DNA/RNA synthesis inhibitor leads to the quick development of resistance and is therefore usually used in combination with other antibiotics.
Rifampin
Streptobacillus monoliformis can cause _____ fever and _____ fever.
Rate bite fever
Haverhill fever.
Naladixic acid is the precursor to the BSA _____.
Fluoroquinolones.
Genetic mutation, gene transfer from one organism to another, or both, can lead to _____.
Microbial Mediated Resistance
This media, when uninoculated is green.
Hugh Leifson media
These are less toxic and more effective in humans
Synthetic antimicrobials
Alcaligenes and Bordetella are not _____ utilizers.
Bordetella bronchioseptica is NOT normal flora of _____.
Humans
Glucose
Campylobacter is not typically associated with _____.
Outbreaks
This agar is not antagonistic towards antibiotic activity.
Mueller-Hinton agar
Pyomelanin color
Brown
What should the MT do prior to plating Kirby-Bauer inoculum?
Press (formerly) sterile swab against one side of tube to remove excess fluid from it.
Cholera is a _____ disease.
Toxin-mediated
Bartonella quintana is the causative agent of _____.
Trench fever (historically)
Does Burkholderia (Pseudomonas) mallei affect humans?
Rarely
Pyocyanin
Blue green pigment on SBAP. Only produced by P aeruginosa. 4% don’t produce pyocyanin.
Acinetobacter spp. is _____ flora
possibly normal
Macrolides only affect _____
Gram-positive organisms
15 Minutes before next dose
30 minutes after dose
When a trough specimen is taken for the Schlichter test.
When a peak specimen is taken for the Schlichter test.
Largest group of antibiotics
Beta lactams
_____ screening method of sputum samples factors in SEC’s per low-power field and Neutrophils per high power field.
Bartlett’s
Campylobacter motility
Darting motility on wet prep
Lysed blood and tissues are the usual specimen for this organism. Grows on fresh chocolate agar (NOT BAP, NOT MacConkey). Requires prolonged incubation with CO2 (2 weeks). Requires high humidity
Bartonella spp.
Clinical Resistance
Drug is no longer effective for clinical use
against the organism.
This is determined by susceptibility testing.
Haverhill fever has more pronounced _____ than rat bite fever.
GI symptoms
Acitinobacillus, Aggregatibacter, Kingella, Cardiobacterium, Capnocytophaga
The above are considered to be of _____ virulence.
Low
Kirby-Bauer plates should be checked/measured after _____.
16-18 hours
When is a trough specimen taken for the Schlichter test?
When is the peak specimen taken for the Schlichter test?
15 Minutes before next dose
30 minutes after dose
Cary-Blair medium is necessary for _____.
Vibro spp.
Morphology of peptic ulcers
Shallow, oval, erosions on the mucosal surface
Pseudomonas and Burkholderia are MAC _____ and Oxidase _____.
Positive/Positive
Vibrio vulnificans does not spread _____. What is another Gram-negative organism that does not spread in this way?
From person to person
Burkholderia mallei
What is the mechanism of action of Sulfonamides?
Competitive inhibition of enzymes involved in folic acid synthesis
Gastritis and peptic ulcers might be indicative of _____.
Helicobacter pylori
Pyocyanin
Blue pigment that produces reactive O2 species causing tissue damage
Stenotrophomonas maltophila is the _____ most common GNF isolated clinically
3rd
Involved in nosocomial and opportunistic infections
Stenotrophomonas maltophila
Moraxella and elongated Neisseria are MacConkey _____ and Oxidase _____.
Negative/Positive
Small, curved, motile gram-negative bacilli
Prefer microaerobic (5-10% O2) environments
Campylobacter
Arcobacter
Newer, safer agents have minimized the use of this antibiotic due to its toxicity.
Chloramphenicol.
Polymixins are produced by _____.
Paenibacillus polymyxa
Aminoglycosides, macrolides, chloramphenicols, and tetracyclines are _____.
Four types of protein synthesis inhibitors.
Kirby-Bauer plates should be incubated at _____.
35 degrees C
Inverted to avoid excess moisture from collecting on agar surface
The preferred media for Helicobacter pylori is _____ agar with _____ % O2.
Temperature of incubation is _____ and incubation may take _____.
Chocolate
5-10%
35-37 C
1 Week
Mueller-Hinton agar is used in _____.
Kirby-Bauer susceptibility testing
Aminoglycosides are bacter(iostatic/cidal). This antibiotic’s dosage is monitored using _____.
Bacteriocidal
Peak and trough values
These can better withstand beta-lactamases
Cephalosporins
Acitinobacillus, Aggregatibacter, Kingella, Cardiobacterium, Capnocytophaga
Morphologically the above are _____.
(Microscopically)
Gram negative bacilli-coccobacilli
Other species of Chryseobacterium/Elizabethkingia may be varable in terms of their _____ and _____ reactions.
MacConkey and Oxidase
NSAs effective against G+ bacteria
Glycopeptides Bacitracin
Francisella tularensis is the causative agent of _____, which is characterized by the patient having _____.
This is optimally recovered on media with _____.
Tularemia. This disease is characterized by high fever (104 C).
Cysteine.
This spp causes Glanders in horses
Burkholderia mallei
What is the purpose of mucus?
Protects normal gastric epithelium from HCl
What are the four possible types of inhibitors of protein synthesis?
Aminoglycosides
Macrolides
Chloramphenicols
Tetracyclines
Secretes proteases and phospholipases that break down glycoprotein-lipid complexes in mucus
Helicobacter pylori
Gentamicin, Tobramycin, and Amikacin are _____.
Inhibitors of protein synthesis (aminoglycosides)
The ATB activity in a patient’s serum is determined by _____.
Serum bacteriocidal test (SBT)
Asaccharolytic organisms are _____.
Non glucose fermentating/oxidizing
Aminoglycosides are ineffective against _____.
Anaerobes
Incubation of glucose oxidizers
24 - 72 hours 22 -35 degrees C
ACV is oxidase _____.
Positive
Associated with bacteremia and infective endocarditis (5% of endocarditis cases due to these organisms)
HACEK
C in Campy-CVA
Cefoperazone
If pure culture is too heavy relative to the McFarland Standard, we will obtain results that are _____.
Falsely resistant
(More bacteria/area consume more antibiotic leading to smaller zones of inhibition. This makes them falsely resistant.)
Biological resistance
Changes in cell structure or physiology resulting in less susceptibility than previously observed
Cholera toxin is produced by these two serotypes
01 and 0139 of V cholerae
Helicobacter pylori gram staining characteristics
Curved, gram-negative rods
This can be fatal if it is in the bloodstream
Burkholderia (Pseudomonas) mallei
Glanders _____ be transmitted from horses to humans. Glanders ______ be transmitted from human to human.
Can Cannot
Stenotrophomonas maltophilia is _____ flora
Possibly normal
Campy-BAP contains the two antibiotics _____ and _____ in order to suppressthe growth of normal fecal flora.
vancomycin, trimethoprim
Chryseobacterium meningosepticum has been renamed to
Elizabethkingia meningoseptica
Chronic gastritis
Long-standing inflammation with mucosal atrophy, metaplasia, possibly dysplasia (malignant potential)
Warthin-Starry silver stain
Stain for biopsies of suspected Helicobacter pylori
Blue pigment that produces reactive oxygen species
Pyocyanin
This GNBC will not grow on MAC and is Oxidase+
Kingella
Aminoglycosides are not recommended with _____.
NSAIDs
Infections of Vibrio parahaemolyticus present with _____ diarrhea.
How many V haemolyticus cases are there per year in the US?
Watery
4500
What is Campy-CVA good for?
Arcobacter and Campylobacter recovery.
Inhibits protein synthesis in host cell
Exotoxin A
Pyocyanin is only produced by _____.
P. aeruginosa
The metabolism of glucose to pyruvate occurs through these three pathways.
EMP, ED, PP
Contraindicated for renal patients. Patient should also avoid the use of NSAIDs when taking this antibiotic regimen.
Aminoglycoside regimens
What are polymyxins derived from?
Paenibacillis (Bacillus) polymyxa
Three Burkholderia spp of significance
cepacia mallei pseudomallei
Contaminated oysters may contain this microorganism.
Vibrio vulnificans
Pseudomonas is MacConkey _____ and Oxidase _____.
Positive
Positive
Infection arises from cats harboring fleas. Causes bacteremia, enlarged lymph nodes, and pustule at site of infection.
Bartonella henselae
Cat scratch fever
Aeromonas lactose fermentation
LF and NLF
What are the preferred specimens for Vibrio vulnificans?
Wounds, blood, or stool (due to ingestion of seafood)
T/F All Pseudomonas aeruginosa produce pyocyanin
F – 4% do not produce pyocyanin
O2 requirements of glucose oxidizers
Obligate aerobes
Acinetobacter spp does not reduce _____ to _____.
Nitrates (NO3) to Nitrites (NO2)
Arcobacter and Campylobacter recovery is best done on _____ agar.
Campy-CVA
This inhibits intestinal flora in TCBS media
High pH (8.6)
Susceptibility testing is also referred to as _____.
Sensitivity testing.
Antibiogram
Guides physicians in selecting empiric therapy for future patients with the expectation of optimizing outcomes.
This organism’s normal habitat is gastric mucosa. It causes chronic infection and its transmission is poorly understood (oral/oral, fecal/oral)
Helicobacter pylori
PBPs are necessary for _____.
cell wall synthesis in G+ bacteria
Urease positive organism with corkscrew motility.
Helicobacter pylori
Some GNF are oxidizers of _____ and some are _____.
Glucose Asaccharolytic
Beta lactamase is produced by Gram _____ bacteria
Positive and negative
What does no reaction in both tubes indicate?
Unknown is asaccharolytic.
What causes meliodosis?
Burkholderia pseudomallei
Polymyxins are both _____.
bacteriostatic and bactericidal
Extended spectrum beta lactamases confer resistance to _____.
extended spectrum cephalosporins and monobactams
Death from cholera occurs due to _____.
Hypovolemic shock secondary to fluid loss. Dehydration.
Vibrio vulnificans is found in what two types of water?
Brackish, Seawater
This is used as a last resort against Pseudomonas aeruginosa
Inhibitors of cell membrane function
Acinetobacter is oxidase _____.
Negative
ACV all grow on _____, _____, and _____.
SBAP, Chocolate, and MAC
Environmentally, Burkholderia pseudomallei is found in _____.
Soil, rice paddies
Any process in which the O2 of a compound is increased.
Oxidation
Vibrio, Aeromonas, and Chromobacterium are all oxidase _____.
Positive
Chlamydia, Rickettsia, and Rickettsia-like organisms can be treated with what two antibiotics?
Tetracycline
Doxycycline
Inhibitors of protein synthesis are either _____ or _____.
Bactericidal
Bacteriostatic
Bacteriostatic agents are _____.
Inhibitory
In TCBS what inhibits G+ organisms?
Bile salts
These Vibrio serotypes have been involved in epidemics and pandemics
01 and 0139
What are nitroimidazoles?
NSA effective against anaerobic bacteria
Aminoglycosides are inhibitors of _____ synthesis.
Protein
How should ACV be incubated?
24 hours @ 35 degrees C in ambient CO2
MAC should only be incubated in ambient air
Etiological agents of gastritis
Alcohol, Smoking, Radiation
Chronic H. pylori infection
VISA and VRSA are susceptible to _____.
(3)
Daptomycin
Rifampin
Tetracycline
Associated with human bite wounds or closed fist wounds (abrasions from facial punches cause someone was throwin shaaaade)
Eikenella corrodens
Is Vibrio spread from person to person through casual contact?
Transmission through casual contact is not very likely. It is transmitted mostly through fecal-oral transmission
Surface carbohydrate that impedes phagocytosis
Alginate
ES Beta lactams are derived from _____ and confer resistance to _____ and _____
Beta-lactams
Penicillins and cephalosporins
Patients requiring chloramphenicol should be monitored carefully for _____.
Bone marrow aplasia
Trimethoprim is frequently combined with _____.
Sulfonamides. An inhibitor of (other) metabolic processes.
Shallow, oval, erosions (ulcerations) on the mucosal surface
Morphology of peptic ulcers
What does the D-test indicate?
Presence of macrolide-inducible resistance to clindamycin produced by an inducible methylase (which alters the common ribosomal binding site for macrolides, clindamycin, and Group B Streptogrammins).
Possible antibiotics againsy V cholerae are _____ (3).
Chloramphenicol
Erythromycin
Sulfa drugs
_____ is the drug of choice for susceptibility testing of Campylobacter.
Erythromycin
Preferred habitat of AVC is
Water
Indicator in Hugh-Leifson OF media
Bromthymol blue indicator
The “urea breath test” is associated with this organism.
Helicobacter pylori.
Up to _____ disks can be applied to a 150 mm plate.
Up to _____ disks can be applied to a 100 mm plate.
12 disks
6 disks
What is a good way to determine if a treatment is effective?
Perform an SBT
Kingella may be a risk for _____.
Poor oral hygiene
Inhibits protein synthesis in host cells. Virulence factor of Pseudomonas aeruginosa
Exotoxin A
Kirby-Bauer susceptibility testing uses _____ agar
Mueller-Hinton
Melioidosis is also known as what?
Whitmore’s disease
Aminoglycosides are often used in combination with _____ or _____, such as _____
Beta-lactams Glycopeptides Vancomycin
Alcaligenes and Bordetella are MacConkey _____ and Oxidase _____.
Positive, Positive
This organism does and doesn’t appear mucoid in terms of its plate morphology.
Pseudomonas aeruginosa
The most common (bacterial) etiologic agent of gastroenteritis in the U.S.
Campylobacter (Salmonella very close)
Broad spectrum antibiotics are _____.
Antibiotics effective against Gram+ and Gram- bacteria
This BSA is bacteriostatic and inhibits protein synthesis.
Tetracycline.
2 NSAs effective against aerobic bacteria.
(Commonly paired together)
Aminoglycosides
Sulfonamides
Transmission of AVC can occur through ingestion of what three food items?
Produce, meat, seafood
Water is the preferred habitat of what three organisms?
V, A, C
Trimethoprim is frequently combined with
Sulfonamides
One of the most important treatments to cholera is _____.
rehydration
Molecular assays of Campylobacter are based on PCR amplification of _____.
16S rRNA gene
There are _____ cases of cholera annually and _____ deaths.
3 to 5 million 100,000
Pseudomonas aeruginosa frequently causes infections in ________ patients.
Cystic fibrosis
This organism can cause gastroenteritis with diarrhea (most often in children), it is found in freshwater and chlorinated water, is G-, oxidase+, beta hemolytic bacilli that produces deoxyribonuclease. Can cause HUS with kidney failure.
Aeromonas spp.
Aeromonas hydrophila
Ubiquitous pathway in both eucaryotes and procaryotes.
EMP
There has been increasing resistance to _____ due to bacteria producing enzymes which inhibit their actions.
Beta-lactams
Three glucose fermenters
VAC
Two Bartonella spp. of interest are _____ and _____.
Bartonella quintana
Bartonella henselae
What is an E-test
Gradient diffusion method using plastric strips containing varying concentrations of an antimicrobial.
Vibrio vulnificans can release toxins such as _____, _____, and _____.
Lipases, Proteases, and Collagenases
C violaceum can be detected with a(n) _____.
PCR Assay
Third most requently encountered GNF clinically
Stenotrophomonas maltophilia
Most commonly isolated NGF clinically
Pseudomonas aeruginosa
Anaerobic degradation of glucose to pyruvate produces _____ ATP.
1
Stenotrophomonas is oxidase _____.
Negative
Asaccharolytic
Term for bacteria that do not oxidize or ferment sugars.
Acid (yellow) only in open tubes means _____.
Acid (yellow) in both OF media tubes indicates _____.
No reaction in either OF tubes indicates _____.
Oxidative
Fermentation or possibly fermentation and oxidation
Assacharolytic
Able to survive in harsh environments and displays resistance to antimicrobial agents
Pseudomonas aeruginosa
Changes in cell structure or physiology resulting in less susceptibility than previously observed
Biological resistance
What media does Brucella optimally grow on?
Brucella agar
(adds heated horse serum)
Pigment that helps microbe obtain iron from the environment
Pyoverdin
Beta lactams and aminoglycosides
Two structural classes of antibiotics
Vibrio and Aeromonas are MacConkey _____ and Oxidase _____.
Positive/Positive
Pseudomonas aeruginosa TSI Results
K/K gas- H2S-
Sulfonamides are frequently combined with
Trimethoprim
Burkholderia cepacia grows on
BAP, Choc, MAC
What competes to attach to Pseudomonas?
Aminoglycosides
and
Cations (Ca++ and Mg++)
With high CO2 and high humidity, this will show good growth on BAP. Pale yellow pigment, pits (corrosion) in the agar. Bleach-like odor.
Eikenella corrodens
Most common sites of peptic ulcers (three, from most frequent to less frequent)
First portion of duodenum
Stomach (antrum)
GE junction
Eikenella corrodens is MAC _____ and Oxidase _____.
Negative
Positive
What are bacitracin and glycopeptides?
NSA effective against G+ bacteria
Nitroimidazoles are _____.
NSA effective against anaerobic bacteria
Eikenella corrodens is MacConkey _____ and Oxidase _____.
Negative/Positive
What interferes with antibiotics targeting folic acid synthesis (e.g., sulfonamides)?
Thymidine
This aspect of Hugh Leifson OF media enhances acid formation
Increased CHO concentration
This Vibrio spp. may be found in brackish water and in seawater. May cause diarrhea, cramping, and nausea. Illnessis usually self limiting.
Vibrio parahaemolyticus
Acitinobacillus, Aggregatibacter, Kingella, Cardiobacterium, Capnocytophaga
The above are _____ growers, taking _____ at 35-37 degrees C
Slow
48 Hours
What must be done to samples in preparation for the Schlichter test?
Dilutions are set up and inoculated with bacterial isolate from patient.
Diluted samples are incubated overnight.
What does acid (yellow color) in both Hugh-Leifson OF tubes indicate?
Unknown performs fermentation OR both oxidation AND fermentation.
These act as a detergent to open up cell membranes
Polymixins
Biopsies of suspected Helicobacter pylori may be stained with this histological stain.
Warthin-Starry silver stain
What is cellular respiration?
Release of energy stored in chemical bonds of glucose and other carbohydrates to produce ATP. Includes use of oxygen as the final e- accepter in ETC.
Extended spectrum antibiotics have greater activity against _____.
Gram- bacteria
Medium to large, smooth, opaque colonies with greenish hue on SBAP. Possibly beta hemolytic
Vibrio
Macrolides are most effective against _____ bacteria because _____.
Gram positive
They are too large to penetrate the outer membrane of Gram negatives
Pasteurella is MacConkey _____ and Oxidase _____.
Negative/Positive
Most common cause of acute gastroenteritis in U.S.
(19-21m cases per year)
Norovirus
How does sensitivity testing help patients in the distant future?
Drives drug research and monitors evolution of resistance.
What is the lifetime risk of peptic ulcer disease?
10% for males
4% for females
How are Campylobacter and Arcobacter transmitted from animals to humans?
Animal feces contaminating water.
Vaccines for this condition only exist outside of the US.
Cholera
Glucose oxidizers are _____ gram _____ _____
Nonfermentive Gram- Bacilli
What does B mallei cause? What does B pseudomallei cause?
Glanders
Meliodosis
Stenotrophomonas maltophilia motility
Motile with a tuft of flagella
With sputum screening, a score of 0 or less indicates _____.
Lack of inflammation and/or contamination with saliva (too many SEC’s)
Gram-negatives are resistant to macrolides because _____.
macrolides cannot pass through outer cell membrane
What are the virulence factors of Vibrio cholerae?
01 and 0139
Hemolysins
Cytotoxins
Pili
Chloramphenicol
Erythromycin
Sulfa drugs
Antibiotics against V. cholerae
_____ antibiotics are more toxic and less effective to humans.
Natural
Penicillins
Minimal Inhibitory Concentration
Minimum drug concentration at which the bacterial population is inhibited and does not show visually discernable growth.
Gram stains of G- nonfermentive bacteria should not be performed from this agar.
MacConkey
Aminoglycosides are contraindicated in _____ because _____.
Renal patients
These require elimination via the kidneys
Eikenella corrodens is normal flora of _____.
The mouth
Resistance to vancomycin occurs because of _____ reducing antibiotic’s ability to bind microbe.
altered cell wall precursors
Semi-synthetic antimicrobials are _____.
chemically-altered natural compounds
Unknown performs fermentation OR both oxidation AND fermentation
Acid (yellow color) is produced in both Hugh-Leifson OF tubes.
Pure culture is _____ McFarland Standard. This is equivalent to _____ CFU/mL.
- 5 McFarland Standard
- 5x108 CFU/mL
Beta lactam rings are formed by
The binding of two amino acids: Cysteine and Valine
If pure culture is too light relative to the McFarland Standard we will obtain _____.
False susceptibility
Reemerging bacteremia, endocarditis, and lymphadenopathy may indicate the presence of _____, especially in homeless, HIV, or immunocompromised patients. Transmitted by body lice.
Bartonella quintana
Length of time
Temperature
O2 / CO2 requirements
Three considerations an MT must make when incubating a microorganism
GNB Growth on MacConkey
Typically positive (clear).
Changes in the cations Mg++ and Ca++ would most noticably affect the resistance of _____.
Pseudomonas spp.
What does the Schlichter test provide?
(2)
MBC and MIC
Kingella is normal flora of the _____, _____, and _____.
Mouth
Throat
Genitourinary tract
Scarring
Perforation
Malignant transformation (rare)
Possible complications of peptic ulcer disease
Imbalance between mucosal defense mechanisms (mucus) gets produced to protect columnar epithelium and HCl production may occur in response to this organism.
Helicobacter pylori
What are some notable beta-lactamases?
3 major, 2 bonus.
Penicillinases
Cephalosporinases
ESBL’s
Bonus:
Cephamycinases
Carbapenemases
Vibrio spp requires this particular type of transport media. Why can’t it use other transport media?
Cary-Blair. Other media can be toxic.
Nitrofurantoin
Antibiotic in which the exact mechanism is unknown. Only works within the urinary tract
What color is uninoculated Hugh Leifson media? How deep should the MT stab this media?
Green
Within 1/4th of an inch from the bottom of the tube
Cephalosporins are structurally similar to
Penicillins
Three considerations an MT must make when incubating a microorganism
Length of time
Temperature
O2 / CO2 requirements
What sort of results can an E-test provide? Why would a clinician not perform an E-test
MIC
Very Expensive
Glycopeptides are a(n) _____ that is used for _____.
Antibiotic
Gram+ organisms
Violet colonies on SBAP. Infections are rare but severe. Begins with cellulitis, disrupted skin. Procedes to lymphadentitis. Systemic shock possible with abscess formation and shock.
Chromobacterium violaceum
What is important about Aminoglycosides having a net positive charge?
Facilitates attachment of antibiotic to cell.
Stenotrophomonas is MacConkey _____ and Oxidase _____.
Positive/Negative
Decreased peptone concentration is a feature of _____.
Hugh Leifson OF media
For the treatment of Vibrio cholarae, treatment with the three antibiotics, _____, _____, and _____, may be indicated due to resistance developing to tetracycline and doxycycline.
Chloramphenicol, Erythromycin, Sulfa drugs
Sensitivity testing helps currently infected patients by _____.
Tailoring treatments of individual patients.
Specimen requirements for VAC. What media should these be transported in?
Stool, rectal swabs. Cary Blair medium
Antibiotic used against Gram+ organisms
Glycopeptides
What do bile salts in TCBS do?
Inhibit G+ organisms
Exotoxin A
Inhibits protein synthesis in host cells. Virulence factor of Pseudomonas aeruginosa
Media used for oxidative-fermentation testing.
Hugh-Leifson OF media
Pyocyanin
Blue pigment that produces reactive oxygen species
If Vibrio is Oxidase tested from MAC what can happen?
Lactose fermentation acidifies the medium to below pH 5.1, which can result in a false negative for Oxidase.
Are macrolides bacteriocidal or bacteriostatic?
Bacteriostatic
Contamination of what may lead to an infection of Vibrio vulnificans?
Seafood (Oysters)
In oxidation, _____ are formed with no _____ produced.
Weak Acids Gas
Two very important oxidase positive, non-fermentative GNB are _____.
Pseudomonas and Burkholderia
Most nonfermentive GNB possess the ability to grow on _____.
MacConkey
Microbial Mediated Resistance is _____ and Environmentally mediated resistance is _____.
Predictable
Unpredictable (relatively)
Microbial Mediated Resistance
Intrinsic/natural/consistently inherited resistance resulting from organism’s physiology.
UTIs can be treated with _____.
Sulfonamides
Columbia CNA agar contains _____ which is used to derive _____.
Naladixic Acid
Floroquinolones
Pseudomonas aeruginosa is ______ normal flora.
Rarely
Pathogenis of Vibrio vulnificans can lead to both _____.
Diarrhea and vomiting. Extension of disease beyond the GI tract.
Acitinobacillus, Aggregatibacter, Kingella, Cardiobacterium, Capnocytophaga
What are the O2 requirements of the above?
What do they grow well on?
Are they normal flora for humans?
Capnophiles (5 to 10% CO2)
SBAP and Chocolate.
Many are normal flora but Acitinobacillus is NOT normal flora. It is often found in bite wounds as it is normal for for animals.
Acinetobacter spp is oxidase ______ and catalase ______
Negative, Positive.
Intrinsic/natural/consistently inherited resistance resulting from organism’s physiology
Microbial Mediated Resistance
What are the incubation requirements of glucose oxidizers
24 - 72 hours 22 -35 degrees C
Francisella tularensis is optimally recovered on _____ because it contains _____.
Buffered charcoal yeast extract.
Contains cysteine.
Campylobacter is transmitted by _____
Ingesting contaminated water or food
Synonymous with anaerobic metabolism
Fermentation
What are two types of resistance?
Clinical and biological resistance.
Anaerobes are not affected by _____.
Aminoglycosides
Are beta lactams BSA or NSA?
BSA
NSA effective against aerobic bacteria (2)
Aminoglycosides Sulfonamides
Inhibitors of cell membrane function are often used _____.
as a last resort e.g. against Pseudomonas aeruginosa
Why can’t glycopeptides be used on GNB?
Glycopeptides are too large to penetrate the outer cell membrane of GNB.
Results from physical/chemical characteristics of the environment
Environmentally mediated resistance
Consequences of H pylori infection
Chronic gastritis
Peptic Ulcer Disease
Gastric Carcinoma
By age 50, _____ is found in 50% of asymptomatic US adults
Helicobacter pylori
Possibly normal flora
Stenotrophomonas maltophilia
Cholera differs from dysentery because _____.
Cholera does not produce blood in the stool and there is an absence of inflammatory cells.
T or F: All antibiotics are antimicrobials
True
Pseudomonas aeruginosa is MacConkey
positive (and clear)
Bartonella is ideally recovered from this media
Chocolate
Campylobacter Gram stain
Small curved gram-negative bacilli
Antimicrobial agent
Chemical substance derived from a microorganism or is produced synthetically that inhibits multiplication and growth of microorganisms. Refers to more human-made bacteriocidal agents
What does high pH (8.6) in TCBS do?
Inhibits other intestinal flora
Metronidazole works against _____ organisms, especially ones that are _____.
Anaerobic
Gram-
The purpose of bactericidal agents is to _____.
kill bacteria
What is the course of treatment for Vibrio parahaemolyticus
Hydration. ATB typically not necessary.
Tetracycline for severe cases
Burkholderia (Pseudomonas) mallei is responsible for what disease? How is this treated?
Glanders in horses
Tetracyclines
ATP is produced with _____.
The energy stored in the chemical bonds of glucose.
What enzymes do BL antibiotics bind to?
PBP
Tiny GNCB on BAP and Chocolate.
3 - 5 days increased CO2.
Kingella
Toxicity/side effects to antibiotics range from nausea to very severe symptoms such as _____.
Nephrotoxicity
Bone marrow toxicity
Allergic reactions
MIC can be detected by what two analysis methods?
Vitek and the E-test
Glucose is an important carbon source for what cellular function?
Cellular respiration
What two factors are important to check with disk diffusion disks?
Age and storage conditions.
Macrolides are inhibitors of _____. Two examples of macrolides are _____.
Protein synthesis. Erythromycin, Clindamycin
When would performing an E-test be advised?
To determine MIC when you have fastidious or slow growing organisms that do not work well using automated methods.
How many directions should the MT streak the surface of a Kirby-Bauer plate to ensure confluent growth?
Three
Aminoglycosides have a net _____ charge.
Positive
What does the Schlichter test determine? Why is this important
ATB activity in the patient’s serum.
Determines if the treatment is effective or not.
Antibiotic disks need to be added within _____ minutes of applying the microorganism to the plate using the Kirby-Bauer procedure.
15 Minutes
AVC is transmitted primarily through _____.
Ingestion/exposure to contaminated water
Are inhibitors of cell membrane function more or less toxic to humans?
More
Alcaligenes and Bordetella (nonpertussis) are MacConkey _____ and Oxidase _____.
Positive/Positive
Precursors for DNA synthesis are produced in what pathway?
Folic acid pathway
Acinetobacter spp. is the _____ most common GNF isolated clinically
2nd
Incubation temperature for C jejuni and C coli
42 degrees
What media is Campylobacter optimally recovered from?
CAMPY-BAP
Erythromycin and clindamycin are examples of what class of antibiotic? Which microbes are these not effective against?
Macrolides. Gram- bacteria – these are too large to pass through the outer membrane
Chryseomonas is MacConkey _____ and Oxidase _____.
Positive/Negative
Pyruvate feeds into the _____ and then into the _____.
Kreb’s Cycle ETC
These antibiotics are both bacteriostatic and bactericidal
Polymyxins
Antibiotics that inhibit cell membranes cause _____.
cell membrane destruction, leading to the leakage of ions and macromolecules
Infections with campylobacter are typically more severe in _____ patients.
AIDS
Pyoverdin (fluorescein) flouresces
Yellow
Strongly linked to contaminated sea food
Vibrio cholerae
Can be natural, synthetic, or semi-synthetic
Antimicrobials
Chromobacterium colony morphology
Black to dark purple and has an almond-like smell on SBAP.
Vibrio Aeromonas and Chromobacterium are Gram _____.
Negative
Floroquinolones are _____ spectrum antibiotics that are derivatives of _____.
Broad
Naladixic Acid
Cefoperazone
C in Campy-CVA
What are the results of an oxidative organism in Hugh-Leifson OF media?
Acid (yellow) in open tube only
Glycoproteins bind to _____.
precursors of cell wall synthesis
What is the term for bacteria that do not oxidize or ferment sugars?
Asaccharolytic
What is the advantage of cephalosporins?
They can better withstand beta lactamases
Cardiobacterium hominus is normal flora of the _____. Bacteremia and endocarditis may result from _____. This is only isolated from _____.
Mouth
Recent dental work
Blood cultures
BP equation
COxPR
Most non-fermentative bacteria are oxidase
positive
Campylobacter pathogenesis infections are typically _____ and don’t require _____.
Self-limiting
Antibiotics
Chronic gastritis can lead to Helicobacter pylori becoming _____.
Normal flora
Three antibiotics that are inhibitors of other metabolic processes
Sulfonamides
Trimethoprim
Nitrofurantoin
Chromobacterium lactose fermentation
NLF
Pigs
Poultry
Sheep
Bulls
Reservoirs for Campylobacter and Arcobacter
If Kirby-Bauer agar is too deep, this results in _____.
(2 Factors)
Smaller zones of inhibition
False resistance
Antibiotic
Chemical substance produced by a microorganism (typically fungus or bacteria) that inhibits multiplication and growth or kills other microorganisms.
What is Pseudomonas aeruginosa resistant to?
Penicillin and ampicillin
Rice water stools are indicative of _____.
cholera
Pseudomonas aeruginosa is commonly found in patients with _____.
CF
Alginate
Surface carbohydrate that impedes phagocytosis
T / F
Molecular methods and commercial enzyme immunoassays are available for Helicobacter pylori
T
If an ESBL is detected the MT should _____.
report ALL penicillins, cephalosporins, and aztreonam as resistant even if in vitro tests say otherwise.
Actinobacillus, Kingella, and Cardiobacterium are MacConkey _____ and Oxidase _____.
Negative/Positive
Second, third, fourth, and fifth-generation cephalosporins are sometimes referred to as _____.
Extended spectrum antibiotics
Surface carb that impedes phagocytosis
Alginate
What is a CRE?
What is important to remember about CREs?
Carbepenem resistant enterobacteriaceae.
CRE strains of an organism (Ec, Kp or Pa) does not mean ALL of the organisms are CRE.
How should Campylobacter be incubated?
Campylobacter prefers microaerobic conditions (5-10% O2 (NOT CO2) and 85% N2). Temperature varies per species.
42 for jejuni / coli
35 for doylei
Why might tetracycline and doxycycline be toxic to human cells?
Works against intracellular pathogens such as Chlamydia, Rickettsia, and Rickettsia-like microorganisms. May damage human cells as a result of damaging pathogens. Also, Rickettsia and mitochondria may share a common ancestor.
T / F
Vibrio cholerae and vulnifcans are to be reported to the CDC but parahaemolyticus does not need to be.
F
All need to be reported
This microorganism is black to dark purple and has an almond-like smell on SBAP.
Chromobacterium
What is the grading scale for neutrophils?
Neutrophils per low-power field (10x)
0 = Less than 10
+1 = 10 - 25
+2 = Greater than 25
+1 = Mucus
This organism is found on plants, in soil, and in water. It is spread from person to person through kissing and doorknobs. It often colonizes the respiratory tract of CF patients.
Burkholderia cepacia
Non-fermentive G- bacilli grow on _____ and _____ media. GNF can also be referred to as _____.
SBAP and Chocolate
Glucose Oxidizers
MRSA resistance is due to MecA gene coding for _____.
An alternative PBP called PBP 2a
Positive on MacConkey but clear.
GNF
P aeruginosa grows well at _____ C.
42 degrees C
Bordetella brochiseptica is normal flora of _____ and _____.
Dogs and cats
Can cause severe dehydration, hypotension, death. Most people exposed to this organism remain asymptomatic but shed bacteria in stool for 7 to 14 days.
V cholerae
Chryseobacterium meningosepticum is associated with _____.
Neonatal meningitis
What are polymixins?
NSA effective against G- bacteria
Any reaction in which the positivity increases from electron loss
Oxidation
Oxygen is excluded in
fermentation
ESBLs do not affect _____ or _____.
Cephamycins or carbepenems
35 degrees C
With CO2 if required
Storage of KBDD plates
The Schlichter test requires _____.
Two specimens. A trough specimen (15 min before next dose) and peak specimen (30-60 min after dose when antimicrobial [] is highest
Reservoirs for Campylobacter and Arcobacter
Pigs
Poultry
Sheep
Bulls
One of the advantages of disk diffusion is that it is _____ and _____.
Constant, reproducible
How are Hugh Leifson OF media tubes prepared?
Tube 1: Open and exposed to air. Loose lid. Tube 2: Overlaid with mineral oil. Closed lid.
Antibiotics that affect cell wall synthesis are relatively _____ to humans
Non-toxic
Chromobacterium violaceum is MacConkey _____ and Oxidase _____.
Positive/Positive
This pathway is greatly used by aerobic bacteria
Entner-Doudoroff Pathway (ED)
Tetracycline is a _____ _____ that inhibits protein synthesis.
Bacteriostatic
BSA
Pseudomonas and Burkholderia are oxidase _____.
Positive
NSAs effective against G+ bacteria
Bacitracin, glycopeptides
Vibrio cholerae has shown resistance to _____ and _____.
Tetracycline Doxycycline
Vancomycin is _____ glycoprotein that _____.
large
inhibits cell wall synthesis
HACEK
Organisms that are normal flora of oral cavity, upper respiratory and genitourinary tracts.
What is the difference between a microorganism being susceptible and resistant?
Susceptibility means the organism is inhibited or killed by the actions of an antibiotic.
Resistant means the organism is not inhibited or killed by the actions of an antibiotic.
NSA effective against anaerobic bacteria
Nitroimidazoles
Chemical substance derived from a microorganism or is produced synthetically that inhibits multiplication and growth of microorganisms. Refers to more human-made bacteriocidal agents
Antimicrobial agent
Bartlett’s screening method of sputum samples does what?
Takes into account SEC’s per low-power field and Neutrophils per high power field.
Hypovolemic shock secondary to fluid loss. Dehydration.
Cause of death in cholera patients.
Mechanism of action of beta lactamase
Breaks open beta lactam rings
NSAs effective against G- bacteria
Polymixins
Chryseomonas and Flavimonas are MAC _____ and Oxidase _____.
Positive
Negative
What are some examples of environmentally mediated resistance
pH
Anaerobic atmosphere
Cation concentrations of Ca++ and Mg++
Thymine-Thymidine content
VISA and VRSA are examples of _____.
VISA and VRSA are subpopulations of _____ with resistance to _____.
Heteroresistance
MRSA
Vancomycin
Environmentally, Burkholderia cepacia is found in _____.
Soil, Water, Plants
Sulfonamides, Trimethoprim, Nitrofurantoin
Inhibitors of other metabolic processes.
Beta-lactamase will not affect this particular drug
Vancomycin
Changes from blue-green to yellow
Bromthymol blue with shifts in pH
Hugh Leifson OF media features decreased _____.
Peptone concentration
Large, round, raised and opaque colonies
Aeromonas
Campylobacter specimens
Stool and blood
What is the causative agent of cholera (species and two serotypes)?
Vibrio cholerae serotypes O1 and O139
Vaccines for cholera _____.
ONLY exist outside the US
How do polymyxins work against GNB?
Polymyxins work like a detergent and open up cell membranes of GNB.
Kirby-Bauer disk diffusion is a type of _____.
Susceptibility testing
Streaking of Kirby-Bauer samples should be done using a _____ pattern.
Zig-zag
Eikenella and Kingella both show _____ on agar.
Pitting
Kingella dentrificans can grow on _____ media, thus this organism can be found on selective media for _____.
Thayer Martin
N. gonorrhoeae
Rapid-onset, transient, acute gastritis can be triggered by _____.
(4)
Alcohol, Smoking, NSAIDs, Chemo
What are aminoglycosides effective against and NOT effective against?
Variety of G+ and G- bacteria
Anaerobes
Actinobacillus, Aggregatibacter, Kingella, Cardiobacterium, Capnocytophaga
These _____ fermenters are all MAC _____ / OX _____
Glucose Negative/Positive
Anaerobic conditions decrease _____.
aminoglycoside activity
Sensitivity testing helps patients in the near future by _____.
Building an antibiogram to guide physicians in selecting therapy for future patients so as to improve patient outcomes.
pH
Anaerobic atmosphere
Cation concentrations of Ca++ and Mg++
Thymine-Thymidine content
Examples of environmentally mediated resistance
How would a pH decrease affect antimicrobials?
Would decrease erythromycin and aminoglycoside activity
Kirby-Bauer plates should have a constant agar depth of _____.
4 mm
Fluoroquinolones are derivatives of _____.
Naladixic Acid
Virulence factor involved in attachment to cells
Pili
4 mm
Ideal depth of Kirby-Bauer Mueller-Hinton agar
pH decrease _____ erythromycin activity
pH decrease _____ aminoglycoside activity
pH increase _____ tetracycline activity
Decreases (for all three)
Pseudomonas has a net _____ charge.
negative
Fastidious pleomorphic GNB from the oropharynx of rodents.
Streptobacillus monoliformis
_____ to antimicrobials can be considered a virulence factor.
Intrinsic resistance.
Vibrio vulnificans symptoms
Diarrhea AND vomiting
Pigment that helps microbes better survive oxidative stress Promotes survival in the lungs
Pyomelanin
This organism has affinity for bone and heart tissue
Kingella
