Microbiology Exam 2 Flashcards
Tetanus
Etiology: enters body through cut or wound, obligate anaerobe, bacillus, motile
Reservoir: SOIL
Transmission: deep wounds
Signs and Symptoms: high blood pressure, stiff muscles
Treatment and Prevention: shot of tetanus immune gloubulin
Pertussis
Etiology: Bordetella pertussis, gram -, cocobacillus, non-motile, has capsule
Reservoir: humans
Transmission: person to person, droplets
Signs and Symptoms: rapid coughing, vomiting, exhaustion, weight loss/malnutrition
Treatment and Prevention: antibiotics, vaccines, proper hygiene
DTaP vaccine
Chickenpox-Shingles
Etiology: chicken pox/shingles VIRUS, enveloped double stranded DNA, varacella-roster
Reservoir: Humans
Transmission: direct contact, airborne particles, fomites, chicken-pox parties
Signs and Symptoms: fever, rash, lesions, headache, chills, pain, tiredness
Treatment and Prevention: vaccine, acyclovir treatment- helps lessen severity
Gonorrhea
Etiology: physicians required to report, neisseria gonorrehoeae, aerobic, gram-negative, diplococci
Reservoir: humans
Transmission: sexually transmitted
Signs and Symptoms: bleeding, strange discharge, discomfort urinating, but many are not aware that they are infected because they have no symptoms
Treatment and Prevention: antibiotics and abstinence
Meningococcal Meningitis
Etiology: Neisseria meningitidis, gram -, diplococci, non-motile, capsule
Reservoir: humans
Transmission: person to person (coughing, kissing), rare droplets
Signs and Symptoms: sudden fever, vomiting, rash, brain swelling, seizures, sweating, stiff neck, light sensitivity, headache, confusion, low/no appetite
Treatment and Prevention: antibiotics, vaccine
Mononucleosis
Etiology: Epstein Barr virus or human herpes virus, enveloped double stranded DNA, really good at becoming latent, go into latency in nerves,
Reservoir: Humans
Transmission: direct contact with saliva,
Signs and Symptoms: takes 4-7 weeks to show symptoms, swollen lymph nodes in armpits and neck, rash fever, swollen liver, extreme fatigue, head and body ache, sore throat
Treatment and Prevention: no vaccine, only ways to soothe the symptoms
Measles
Etiology: measles virus, enveloped, single stranded RNA-cytoplasm
Reservoir: Humans
Transmission: droplets, contaminated surfaces
Signs and Symptoms: high fever, runny nose, spots in mouth, body rash
Treatment and Prevention: pain treatment and vaccines MMR vaccine (measles, mumps, rubella)
Polio
Etiology: Poliomyelitis. poliovirus, single stranded RNA, has capsid protein coat, mainly affects children
Reservoir: humans, fecal
Transmission: person to person contact, less common droplets
Signs and Symptoms: high fevers, flue like symptoms, small portion of those infected experience intense muscle pain, meningitis, pins and needles, and paralysis
Treatment and Prevention: public sanitation and vaccines
Tuberculosis
Etiology: mycobacterium tuberculosis, non-motile, ACID-FAST, waxy lipid coating, obligate aerobe, “consumption”
Reservoir: humans
Transmission: people cough and the particles fly everywhere and people breathe them in.
Signs and Symptoms: bad cough, pain in chest, coughing up blood, weight loss
Treatment and Prevention: antibiotics for a long time because m. tuberculosis is a slow growing bacteria. Sometimes take 2-3 antibiotics at a time because tuberculosis is one of the most resistant. Vaccine BCG is a preventative.
Influenza
Etiology: influenza virus
Reservoir: Humans influenza B, pigs, ducks, wild birds influenza A
Transmission: droplets, less common person to person
Signs and Symptoms: flu like symptoms, 1-4 day incubation
Treatment and Prevention: vaccination, personal and public hygiene, herd immunity, antiviral drug
Symptom
what the patient feels, i.e. yucky
Factors that affect bacterial growth
temperature, oxygen, pH or acidity, moisture or water, food
Obligate aerobe
has to have oxygen
Obligate anaerobes
cannot have oxygen (intestines)
Facultative anaerobes
can grow in both oxygen and no oxygen but prefers oxygen
Aerotolerant
tolerate oxygen but doesn’t use it
acidic
more hydrogen
basic
less hydrogen
Acidophile
bacteria that like acidic environments (yogurt bacteria)
Neutrophiles
bacterial the like range 7 environments
Alkalphile
bacteria that like basic environments
Isotonic
balanced solutes inside and outside cell membrane
Hypotonic
more solutes IN cell than outside. Water tries to get in but cell wall prohibits
Hypertonic
more solutes outside of cell, water is sucked out of cell. Honey
What does growth mean?
more cells
Binary fission
Membrane starts to pinch, cell wall starts to close off, SEPTEM pinches in middle
How do bacterial reproduce?
Binary fission, allows for exponential growth.
Doubling/generation time
the time it takes for one batch of cells to Double
What are the two media types and give examples
-Selective: MSA and MacConkey
Differential: MSA MacConkey
Selective media type
Only certain TYPES of bacteria can grow on it, i.e. gram positive or negative, “selects for”
Differentail
Bacteria that ferment something i.e. will this bacteria ferment lactose or mannitol?
Closed culture bacteria curve
Lag phase, exponential phase, stationary phase, death phase
Lag phase
beginning phase, takes time for bacteria to adjust
Exponential phase
exponentially grow using binary fission
Stationary phase
cells become limited, wastes buildup, nutrients are used up
Death phase
endospores, bacteria death is more than growth
Biofilm
bacteria uses capsules of sticky polysaccharides to stick together and form a film. Biofilms are detrimental to dental care but perhaps beneficial for gut health if bacterial are harmless to humans
What are the four types of counting microbial growth?
Microscope count, Dilution plate, Turbidity, Coulter counter
Microscope count
count number within one grid
Microscope count
count number within one grid, direct
Dilution plate
Counts only living cells, put inoculation loop through five batches of agar, diluting each as they go. You want between 30-300 to be considered statistically significant, direct.
Turbidity
transmission through media, spectrophotometer, indirect
Coulter counter
uses light to count cells that go through tiny tubes, counts the shadows, direct.
Which provides a more accurate count of microbes growing in a culture, “direct” or “indirect?
Direct because you count each individual one and sometimes just the living cells. (most accurate)
Sterilization
process of killing ALL forms of life. It either IS sterile or it ISN’T
Disinfection
targeting disease-causing agents (pathogens).
Disinfectant
a chemical that kills pathogens, Inanimate objects such as linens
Antiseptic
a chemical that kills pathogens usually restricted
Antiseptic
a chemical that kills pathogens usually restricted to chemicals used on skin and mucosal membranes.
Sanitizers
a disinfectant used on food handling equipment
Degerming
wash off bacteria, doesn’t kill (had washing)
Degerming
wash off bacteria, doesn’t kill (had washing)
Psycrophile
Optimum at around 0 degrees C
Degerming
wash off bacteria, doesn’t kill (hand washing, antibiotic soaps Do kill bacteria)
Thermophile
Optimum around 70 degrees C, Extreme thermophile peaks around 130 degrees C, hydrothermal vents
Thermophile
Optimum around 70 degrees C, Extreme thermophile peaks around 130 degrees C, hydrothermal vents
Microaerophile
requires perfect amount of oxygen, “Goldie Locks”
Bacteriostatic agent
a substance that INHIBITS bacteria growth, doesn’t kill.
How do things like heat and disinfectants kill bacteria?
Injury to the plasma membrane, damage to proteins, damage to nucleic acids
Germicide or bacteriocide
agent that KILLS bacteria
Why is an autoclave more efficient than boiling?
Moist heat, steam under pressure is one of the most efficient sterilizing agents. 121 degrees for 15 minutes. The autoclave pressure allows water to get hotter than the usual boiling point.
Boiling water
kills all vegetative cells within a few minutes
Pasteurization
63 degrees for 30 min
72 degrees for 15 sec
-Time and temp are not linear
Dry heat
takes longer and higher temperatures than most heat to kill microbes. Takes longer to reach the same penetration.
- flaming
- incineration
Low temperature
not a method of sterilization but does inhibit the growth of microbes. The enzymes more slower in colder temps
Filtering
used for air and materials that would be damaged by heat
- you CAN sterilize a liquid with filtering
- HEPA filters
Deciccation
removal of all water from a substance
-freeze drying
Ionizing Radiation
causes mutation in DNA and possibly affects enzyme function. X-rays and gamma rays. Very powerful and damaging. used on spices,
UV radiation
used in rooms, lab hoods, etc.
Antimicrobial drugs
need less of,
Antimicrobial drugs
need less of vs disinfectants that you need more of
antibiotics
most that have been discovered have come from soil, bacteria don’t want competition, Flemmings discovery of penicillin against staph aureus
Antimicrobial medications
selective toxicity
Narrow spectrum
targets a few microbes
broad spectrum
broad targets, used to start killing microbes before known pathogen can be isolated
What are the five ways that antibiotics work? (method)
inhibition of cell wall synthesis, inhibition of ribosome (protein synthesis), damage to the plasma membrane, inhibition of nucleic acid, disruption of metabolic pathways
Inhibition of cell wall synthesis
penicillin, cross-bridges synthesis in peptidoglycan, effective against actively growing cells. VANCOMYCIN, BACITRACIN
heavy metals
kill microbes by binding to proteins, thus inhibiting enzymatic activity, small amounts do great damage. Mercury, silver, nickel, copper, zinc
halogens (iodine and chlorine)
bleach, fluoride
alcohols
They work by rapidly denaturing proteins, which inhibits cell metabolism, and by disrupting membranes, which leads to cell lysis, hand sanitizers, tinctures
surfactants (soaps and detergents)
compounds that lower the surface tension of water. Degerming
chlorhexidine
Bisbiguanides,disrupts cell membranes and is bacteriostatic at lower concentrations or bactericidal at higher concentrations, in which it actually causes the cells’ cytoplasmic contents to congeal.
formalin
gaseous disinfectant and biocide,has the ability to kill bacteria, viruses, fungi, and endospores, leading to sterilization at low temperatures,
eythelyne oxide gas
highly penetrating and can sterilize items within plastic bags such as catheters, disposable items in laboratories and clinical settings
peroxygens
producing free radicals that damage cellular macromolecules
peroxygens
producing free radicals that damage cellular macromolecules
Inhibition of protein synthesis
Streptomycin, tetracyline, chloramphenicol, erythromycin
Damage to cell membranes
polymyxin B, disrupts the plasma membrane by attaching to phospholipids, Neosporin
Ehrlich
“silver bullet” for syphilis
Nucleic acid synthesis
Rifampin-blocks transcription
ciprofloxacin- Blocks DNA replication
Disruption of metabolic pathways
sulfonamides, do damage somewhere along the way so that the end result isn’t reached
Antibiotic resistance comes mot commonly from:
spontaneous mutation, plasmids
Four mechanisms of resistance
destroy the drug, modify drugs target site, increase drug elimination through efflux pump, block penetration
Four ways antibiotic resistance is fueled
overuse, use by immunosuppressed individuals, failure to follow prescription and complete dose, use of antibiotics in animal feed.
Antibiotic resistant diseases
MRSA, VRSA (vancomycin), multi-drug resistant TB, penicillin-resistant enterococcus
Phage therapy
introducing viruses into body to attack bacteria, bacteriophages
Probiotics
introduce live, good, bacteria into the body to outcompete any pathogenic, bad, bacteria. good for repopulating
Anti-fungal drugs
fungal cells are very similar to our cells, selective toxicity is much more difficult to attain
Disk diffusion test
look for the zone of inhibition
White blood cells
phagocytosis- engulf bacteria and viruses and digest them, “cell eating”, what fight infections
cytotoxic T-cells
kill virus infected cells. Common cold
B-cells
produce antibodies- target antigens for destruction
Vaccines
mock sickness, prepare your cytotoxic T-cells and B-cells for real viral infection by using pieces. Inactivated form of a disease, collection of antigens from common disease causing pathogens.
Helper T-cells
activate be and CT cells
passive immunization
delivery of pre-formed antibodies through natural (placenta and breast milk), and gamma globulin, anti-venom, and anti-toxins
Active immunization
production of antibodies in the host
-vaccination and natural infection progression
Attenuated vaccines
live, using living but weakened (heat treated) pathogens
Inactivated vaccines
whole agents, killed/inactivated pathogens, boosters
Subunit vaccines
only the antibodies from the pathogen are used, some are recombinant vaccines
Toxoid
inactivated toxins, most problems with bacteria and viral infections are the TOXINS and the PROTEINS that they produce
phycrotrophs
refrigerator temps
