Units 1-3 Flashcards
Nomenclature
Genus species.
First letter of first word capitalized
Second word all lowercased
Gram + vs Gram -
Gram+: thick peptidoglycan layer; NAM and NAG connected with a peptide (purple)
Gram-: thin peptidoglycan layer; endotoxin with LPS release (red)
Viral structure
- Capsid-> surrounds genome
- Nucleic Acid-> ds and ss ; DNA or RNA
- Spikes-> attachment and determines host cell
Bacterial Structure
- Fimbriae-> attachment
- Flagella-> motility/movement
- Axial Filament-> endoflagellum
- Pili-> attachment and conjugation
Plasmids (bacterial structure)
DNA, circular, 0 or 100s, smaller, disease causing genes (antibiotic resistance) (toxin production)
Capsules vs Endospores (bacterial structures)
Capsules: Found inside body, protects from phagocytosis, active, permeable, both gram negative and positive can make
Endospores: Found outside of body, protects against harsh environments, dormant, non-permeable, peptidoglycan, only gram positive but not all
Methods of Identifying Microorganisms
-Morphology (Microscopy)
-Staining (mainly Gram-staining):
>Basic Acidic Dyes
>Simple Staining
>Differential Staining (Gram Stain procedure)
>Special Stains
-Biochemical (enzymatic metabolism relating to identification)
-Serological (antibody identification->ELISA)
-PCR (DNA genome identification)
Media
- Selective: selects for one, suppresses the other
- Differential: see differences, usually by color
Sterilization vs. Disinfection vs. Antisepsis
- Sterilization: complete elimination of microbes
- Disinfectant: surfaces/ inanimate objects
- Antiseptic: used on living tissue
Antivirals
- Acyclovir: DNA viruses; inhibits DNA replication
- Tamiflu: targets neuraminidase
Chemical Methods of control
- Alcohol: ethanol (hand sanitizer) and isopropanol (alcohol)-> targers membranes, cidal, broad towards bacteria and enveloped viruses
- Halogens: chlorine (bleach)(disinfectant) and iodine (betadine)(antiseptic)-> targets protein bonding, cidal, broad
- Metal compounds: silver nitrate and mercury-> targets protein bonding, cidal, broad, antiseptic
- Phenolics: triclosan-> targets membrane synthesis(enzymes), cidal, narrow toward bacteria, antiseptic
Physical Methods of Control
- Heat: moist and dry; protein bonding; cidal; broad
- Filtration: broad
- Radiation: ionizing(x-ray) and nonionizing(UV), targets nucleic acid, cidal, broad
- Osmotic Pressure: salt curing and freeze drying, cidal, narrow towards bacteria
Antibiotics (definition)
a medicine that inhibits the growth of or destroys microorganisms.
Definition of Narrow vs. Broad Spectrum Antibiotics
Broad: Bacteria and viruses
Narrow: Bacteria or Viruses
Definition of Bacteriostatic vs. Bacteriocidal
- Static: inhibit the microbes growth
- Cidal: kill the microbe
Examples of Antibiotics (just know the 8 we discussed in class & the specifics on your tables)
- Inhibition of Cell Wall Synthesis (Penicillin)-> static, narrow(gram+)
- Inhibition of Protein Synthesis (Chloramphenicol, Streptomycin, Tetracycline, Erythromycin)-> static, broad (stepto is cidal)
- Plasma Membrane Damage (Polymyxin B)-> cidal, narrow (gram-)
- Inhibition of Nucleic Acid Synthesis (Rifampin & Ciprofloxacin)-> cidal, rifa-> narrow(gram+), cipro-> broad
Types of Vaccines
- Attenuated whole agent-> weakened, living, microbe
- Inactivated whole agent-> dead or inactive
- Subunit-> piece of the microbe (ex.spike, fimbriae)
- Toxoid-> inactivated toxin
- Conjugated-> less reactive piece (ex. capsule) w/ a highly reactive piece (ex. toxin)
- Nucleic acid-> DNA or RNA
Normal Flora
good bacteria
Signs vs. Symptoms
- Sign: measured/seen (vomiting)
- Symptom: how one feels (headache)
Course of Illness
- Incubation: no sign/symptoms
- Prodromal: mild signs and symps
- Period of illness: unique signs and symps
Principles of Disease terminology (i.e. acute, chronic, latent, sepsis, pandemic, etc…)
-Acute: short
-Chronic: long lasting
-Latent: repeatable
-Sepsis: bacteria growing in the blood
Pandemic: cross-continental
Spread of Infection
direct or indirect contact
Nosocomial Infection
infection gained from a hospital
Epidemiology (epidemic, endemic, pandemic)
- Epidemic: an outbreak of a sickness
- Endemic: constantly seen throughout society
- Pandemic: cross continental
Prions
infectious proteins-> causes brain shrinkage and can spread in the body
Pathogen Portals of Entry (Types of Mucus Membranes & Parenteral)
- Mucus membranes: respiratory, GI, genitourinary, conjunctiva
- Parenteral: punctures, any break in skin
- Skin: microbe burrows through skin
Pathogen Transmission (Direct & Indirect examples)
- Direct: person-to-person, droplets, vector(bites)
- Indirect: fomites, vehicles
“Fecal-oral route)
Lysogenic conversion
- process through which a bacterium gains the ability to produce an exotoxin through bacteriophage
- Cholera, botulism, diphtheria
Animal virus replication (+ vs. – strand RNA, dsDNA & retroviral RNA)
- RNA + sense: go straight to the ribosome for replication
- RNA - antisense: contain enzyme to convert to +
- dsDNA: goes to the nucleus to be translated
- Retrovirus RNA: uses transcriptase to hide in the body
Viral Cytopathic Effects
- Syncytia-> host cell membrane fusion
- Transformation-> virus induces rapid uncontrolled cell growth (oncogenesis)
- Inclusion Bodies-> masses of proteins
Bacterial Adherence (structures)
fimbriae, pili, biofilms
*attach to host glycoproteins
Bacterial Invasion & Evasions techniques
Invasion: membrane ruffling-> bacteria induces endocytosis and enters host cell
-Evasion: capsules and waxes (mycolic acid w/ TB), antigenic variation, mimicking host molecules
Bacterial enzymes
- Hyaluronidase: breaks down hyaluronic acid (connective tissue)
- Kinase: breaks down blood clots
- Coagulase: forms blood clots
- IgA protease: breaks down antibodies
Endotoxin
- shed LPS
- Only and All gram negative
- unintentional
- fever (IL-1), inflammation, septic shock
- systemic
- toxic @ high amounts (low toxicity)
Exotoxin
- secreted proteins
- both can make (usually gram positive)
- intentional
- cell specific (usually target plasma membrane)
- localized
- toxic at low levels (high toxicity)
Host Damage (bacteria)
-Siderophores-> steals host nutrients (iron)
C. diff Colitis-> Clostridium difficile
- Gram +
- Endospore
- In soil
- Indirect contact through vehicle
- GI entry
- Acute
HSV-1
- DNA
- Enveloped
- Cold sores
- Humans
- Direct contact through person to person
- GI tract
- Latent
Polio
- Positive RNA
- Naked
- Lytic
- Reservoir: humans
- Indirect contact through vehicle
- GI tract
- Acute
MRSA-> Staphylococcus aureus
- Gram +
- Biofilm
- Reservoir: Humans
- Indirect contact through fomite
- Parenteral
- Acute
Tuberculosis
- Gram +
- Mycolic Acid wax
- Reservoir: humans
- Direct contact though droplets
- Respiratory
- Chronic
Lyme Disease-> Borrelia burgdorferi
- Gram -
- Spirochete
- Axial filaments
- Reservoir: mice
- Direct contact through vector
- Parenteral
- Chronic
Measles
- Negative sense RNA
- Enveloped
- Reservoir: Humans
- Direct contact droplet
- Respiratory
- Acute
- Syncytia
Case Studies
- Case Study 2: AcrAB protein-> gram negative bacteria to pump out unwanted chemical compounds
- Case Study 3: penicillin is a beta lactam ring that binds to DD-transpeptidase (alanyl). Bacteria makes beta lactamase that hydrolyzes bonds in the beta lactam ring in return.
- Case Study 4:
- –Neisseria meningitidis and Streptococcus pneumoniae produce IgA protease.
- –Streptococcus makes pneumolysin is an exotoxin that causes cell disruption and inflammation. It can also make PdgA which protects against host lysozymes by modifying NAG sugars in peptidoglycan.
- –Shiga toxins: exotoxin that shut down protein translation.
