Bacteria Flashcards
Characteristics of bacteria (6)
1) single cell organism
2) contains both DNA and RNA
3) reproduce through binary fission
4) cytoplasm with NO nucleus
5) ribosomes - metabolic activity
6) colonize skin, mouth, hair, gut, and genital tract
What is the communication conduate of a bacteria?
cell wall
What is the “business” end of a bacteria?
protein
Reproduction via binary fission is:
a) fast
b) slow
a) fast
very fast!
Ways to describe bacteria (3)
1) Shape
2) Gram stain
3) Gram stain morphology
4 main shapes of bacteria
1) Cocci* (think “circle”)
2) Bacilli* (think “baton”)
3) Curved
4) Spiral
A purple gram stain indicates…
gram + bacteria
A pink or red gram stain indicates…
gram - bacteria
Gram Stain Morphology Descriptors (3)
1) + or -
2) shape
3) clusters or spirals (for gram + only)
Categories for naming bacteria (2)
1) genus
2) species
What is always capitalized?
a) genus
b) species
a) genus
Gram ____ bacteria have a thick peptidoglycan layer and NO outer membrane
positive
Gram ____ have an outer membrane and a thin peptidoglycan layer
negative
What is the outer membrane composed of?
lipopolysaccharides (LPS) endotoxin
Configuration of gram + peptidoglycan layer
cross-linked between N-acetyl Glutamine (NAG) and N-acetyl Muramic acid (NAM)
How do antibiotics like penicillin target gram + bacteria?
prevent cross-linkages in the peptidoglycan layer
Functions of the cell membrane (6)
1) energy production
2) nutrient storage
3) transport of nutrients and wastes
4) selective transport of molecules
5) site of secretion of toxins and enzymes
6) osmotic barrier
What bacteria cannot be classified as gram + or -?
bacteria in the following genuses:
1) Mycobacterium
2) Mycoplasma
Main examples of diseases caused by Mycobacterium (2)
1) Mycobacterium tuberculosis
2) Mycobacterium leprae (leprosy)
Characteristics of Mycobacterium that make them impermeable to most thing (2)
1) thick membrane capsule
2) mycolic acid wall
What Mycobacterium are known as
“acid fast” bacteria
Stain for visualizing Mycobacterium
Zeihl-Neilson Stain
Mycoplasma do not have a _________
cell wall
don’t stain!
Main Species of Gram + Cocci (2)
1) Staphylococcus
2) Streptococci
Genus of bacteria found in a “grape-cluster berry”
Staphylococcus
Major groups of Straphyloccus bacteria (2)
1) aureus (coagulase positive)
2) non-aureus (coagulase negative)
Which group of Staphyloccus bacteria is more medically important?
a) Staphyloccus aureus
b) Staphyloccus non-aureus
a) Staphyloccus aureus
MRSA
Where to swab for Staphyloccus aureus bacteria? (2)
1) nose
2) butt
Examples of Staphyloccus non-aureus bacteria (many)
S. epidermidis [skin]
S. hominus
S. warneri
S. hemolyticus
S. capitis [head]
MRSA
Methicillin Resistant S. aureus (MRSA)
Streptococci hemolytic patterns (3)
1) Alpha hemolysis: partial lyses of blood cells in the agar (agar goes green)
2) Beta-hemolysis: complete lysis of blood cells in the blood agar
3) Gamma-hemolysis: blood cells not lysed (not really hemolysis)
Alpha Streptococci examples (2)
Viridans Streptococci
Streptococcus pneumoniae
What medical issues is Streptococcus pneumoniae associated with? (4)
CAP, Bacteremia, Meningitis, Otitis media
also part of normal flora
Beta Streptococci examples (2)
Streptococcus pyogenes (Group A)
Streptococcus agalactaea (Group B)
Issues with Strep B Streptococcus in pregnancy
found in female genital tract during pregnancy
at 35 weeks, will swab and give them antibiotics if they have Group B strep
major causes of meningitis, bactoremia (blood), pneumonia in neonates*****
Gamma Streptococci
Enterococci spp. (Group D)
in gut
drug-resistant form - vancomycin resistant enterococci
Gram + Bacilli characteristics
common environmental bacteria
found in chains
Gram + Bacilli examples (many)
Bacillus anthracis
Bacillus cereus
Listeria monocytogenes
Clostridium difficile
Clostridium perfringens
Clostridium tetani
Clostridium botulinum
Propionibacterium acnes
What is unique about Listeria monocytogenes?
Cold Amplification –> grows well at 4 C degrees
better than at 20 or 30 meat
deli in meat for a while in fridge - bad
T or F: Listeria monocytogenes can cross the placenta
TRUE
can infect fetus
can cause placentitis, amnionitis, pre-term labor, spontaneous abortions, still births
Clostridium species characteristics (3)
all anaerobes
form spores, which allow them to remain in the environment for long periods of time
prodigious toxin producers - their primary virulence factor
Propionibacterium acnes causes issues in this type of surgery
shoulder replacement –> cause of prosthetic failure
normally found on the face and causes acne
shoulder and face structurally similar, especially in men
bacteria travels down to shoulder
Gram - Cocci locations (2)
1) oral flora
2) mucous membranes, including genital tract
Gram - Cocci examples (2)
1) Neisseria gonorrhoea
2) Neisseria meningitidis
What bacteria is responsible for recent cases of meningitis in KFLA?
Neisseria meningitidis
Gram - Bacilli characteristics
most numerous bacteria in gut*****
number of sites including fresh water, GI tract
can lead to very serious infections at a number of sites including in blood, wound infections, and pneumonia
quite virulent!
Major issue with Gram - Bacilli
resistance to antibiotics
produce toxins, drug resistant, evade immune response
tend to be multiple drug resistant
Gram - Bacilli examples (many)
Escherichia coli
Salmonella typhimurium
Enterobacter clocae
Citrobacter
Pseudomonas aeruginosa
Klebsiella pneumoniae
Proteus mirabilis
