Bacteriology Flashcards
1
Q
Bacterial Cell Wall (4)
A
- made of PEPTIDOGLYCAN (a sugar/amino acid complex) which is only found in bacteria
- may produce the symptoms of disease
- the site of antibiotic action
- determines if the bacteria is gram + or -
2
Q
Gram +
A
bacterial cell wall is very thick (lots of peptidoglycan)
3
Q
Gram -
A
bacterial cell wall is very thin (little peptidoglycan)
4
Q
Bacterial Structures (5)
A
- endospore
- capsule
- DNA/plasmids
- appendages
- ribosomes
5
Q
Endospore
A
- produced by some gram + bacteria
- coating that surrounds DNA
- outer cell may be destroyed, but DNA will be protected
ex: anthrax, tetanus, botulism
6
Q
Capsule
A
outer covering on cell wall that protects against chemicals, WBCs, etc.
7
Q
DNA/Plasmids
A
- genetic material of the cell
- may be exchanged between bacteria and may contain genes for antibiotic resistance
8
Q
Appendages
A
- pilus may be used to attach onto other cells
- flagella are used for movement
9
Q
Ribosomes
A
where transcription and translation of DNA for protein production occurs
10
Q
Autotrophic Bacteria (Nutrition)
A
make their own energy from the sun (photosynthesis) or chemicals (chemosynthetic)
11
Q
Heterotrophic Bacteria (Nutrition)
A
obtains energy from dead organic material (saprobe) or from living on or in other organisms (parasite)
12
Q
Obligate Aerobe (Metabolism)
A
requires oxygen to live (bacteria that would be found in the lungs)
ex: tuberculosis, leprosy
13
Q
Obligate Anaerobe (Metabolism)
A
dies in the presence of oxygen
ex: tetanus, botulism, gangrene
14
Q
Facultative Anaerobe (Metabolism)
A
can live with or without oxygen (most gut bacteria)
ex: e. coli, salmonella
15
Q
Bacterial Classification
A
basic shape + arrangement
16
Q
Cocci (shape)
A
sphere
17
Q
Bacilli (shape)
A
rod
18
Q
Spirilla (shape)
A
spiral
19
Q
Cocci Arrangements
A
- can be found in single cells, pairs, chains, or clusters
- STREPTO = chains
- STAPHYLO = clusters
20
Q
Bacilli Arrangments
A
- can only divide across short axis
- can grow in singles, pairs, or chains (NO CLUSTERS)
21
Q
Common bacilli
A
any type of clostridium, anthrax
22
Q
Spirilla Arrangements
A
have 1+ twists
23
Q
Common spirilla
A
treponema pallidum (syphilis), borrelia burgdorferi (Lyme disease)
24
Q
Drug Resistance (WHY?, 4)
A
- we use too many antibiotics and we use them incorrectly
- taken incorrectly, antibiotics kill most, but not all of the bacteria present in the body
- this leaves the strongest bacteria alive - they are now immune to the drug
- when these survivors reproduce, the entire new group of bacteria is now resistant
25
Drug Resistance (HOW?, 3)
1. MUTATIONS or changes in the DNA
2. Transfer of genetic material between 2 bacteria - a form of microbial "sex" called TRANSFORMATION
3. Plasmids (extra pieces of DNA) that can enter bacterial cells)
- plasmid is located in one cell
- bacterial cell lyses for some
reason and another cell
picks up the plasmid
- this process is called
GENETIC RECOMBINATION
26
Human practices leading to drug resistance... (6)
1. overuse and misuse of antibiotics (failure to finish prescriptions)
2. patient demand during cold and flu season (using antibiotics for viruses, which only kills good bacteria)
3. use of antibiotics by immunosuppressed patients... they can end up carrying antibiotic-resistant germs and giving them to other people
4. long term use for acne
5. use of antibiotics in animal feed
6. movement of resistant bacteria to new areas because of world travel
27
Bacterial Diseases - Skin
- staphylococcus
- streptococcus
28
Bacterial Diseases - Nervous System
- botulism
- tetanus
- leprosy
29
Bacterial Diseases - Cardiovascular/Lymphatic
- anthrax
- gangrene
- plague
- Lyme disease
30
Bacterial Diseases - Respiratory
- diphtheria
- tuberculosis
31
Bacterial Diseases - Gastrointestinal
- salmonella
- e. coli
- clostridium difficile
32
Staphylococcus
- several species
- GRAM +, AEROBIC, CLUSTERS
- Staphylococcus epidermidis and aureus
33
Staphylococcus epidermidis
a normal skin bacteria
34
Staphylococcus aureus
- most pathogenic
- forms yellow colonies
- problem in hospitals (surgical wounds)
- resistant to many drugs such as methicillin
35
Streptococcus
- GRAM +, FACULTATIVE ANAEROBE, COCCI CHAINS
- Streptococcus pyogenes and necrotizing fasciitis
36
Streptococcus pyogenes
- causes strep throat, scarlet fever, and rheumatic fever
- highly destructive if bacteria reaches deep layers of tissue
37
Necrotizing fasciitis
- "flesh-eating" bacteria
- 40% mortality rate
- destroys tissues as fast as surgeons can cut it out
- attacks skin, muscle, and connective tissue
38
Botulism
- Clostridium botulinum
- food poisoning - usually from canned foods
- OBLIGATE ANAEROBE (found in soil and water)
- GRAM +, BACILLI
- blocks release of acetylcholine needed to transmit nerve impulses (relaxes muscles)
- symptoms = nausea, blurred vision, difficulty swallowing
39
Tetanus
- Clostridium tetani
- OBLIGATE ANAEROBE (common in soil)
- GRAM +, BACILLI
- highly toxic (blocks relaxation pathways of muscles so they remain contracted)
- death results from spasms of repiratory muscles
- vaccine = 100% effective
40
Leprosy
- Myobacterium leprae
- related to tuberculosis
- doesn't gram stain, AEROBIC
- infects skin cells, but lives in nerves (causes sensory loss in skin; easy to injure self)
- lesions form on skin and ooze
- death usually results from complications (like infections)
- 200 cases in US yearly (treat with sulpha drugs)
41
Anthrax
- Bacillus anthracis
- AEROBIC
- GRAM +, CHAINS OF BACILLI
- found often in sheep & cattle (spores eaten in grass)
- human occurrence is rare (people at risk handle animals/wool)
- 3 forms of infection: 1) enter through cut (form pustules), 2) inhaled, 3) eaten (infects intestines)
42
Gangrene
- GRAM +, ANAEROBIC
- several Clostridium species
- death of soft tissue resulting from loss of blood supply
- once tissue starts to die, gas gangrene develops
- treatment = surgical removal
43
Plague
- Yersinia pestis
- GRAM -, AEROBIC
- carried by rats
- 3 types: 1) pneumonic plague, 2) bubonic plague, 3) speticemia plague
44
Lyme Disease
- Borrelia burgdorferi
- GRAM -, SPIRILLA, FACULTATIVE ANAEROBE
- most common tickborne disease in the US
- antibiotics are effective is given early
45
Diphtheria
- corynebacterium diphtheriae
- GRAM +, AEROBIC, BACILLI
- leading killer in children in US until 1933
- airborne, highly contagious
- vaccine is DPT
46
Tuberculosis
- myobacterium tuberculosis
- does not gram stain, AEROBIC
- becoming resistant because patients don't take full course of anitbiotics
- bacteria can live within phagocytes that eat them for weeks
47
Salmonella
- Salmonella gastroenteritis
- "food poisoning"
- GRAM -, ANAEROBIC
- found mostly in chicken and eggs
48
E. coli
- Escherichia coli
- GRAM -, FACULTATIVE ANAEROBIC, BACILLI
- transmitted through contaminated animal/water products
- lives in animal intestines
49
Clostridium difficile
- GRAM +, BACILLI, ANAEROBIC
- causes life-threatening inflammation of the colon
- typically occurs in health-care facilities or in long-term care facilities
- resistant to many antibiotics
