Bio Lect Quiz 28,29,30
What are the 3 functions of an A-B toxin?
1 - Inc cAMP which Inc Fluid secretion 2 - Inhibits protein synth(Euk specific) 3 - Inhibit cell-cell communication(Euk spec)
What are 3 re-emerging diseases worldwide?
HIV SARS Monkeypox
What is the most important nosocomial disease prevention step?
Handwashing
What are the two types of cellulolytic toxins? Which is associated with beta and which is associated with alpha hemolysins?
Hemolysins - Alpha pore complex kills membrane Phospholipases - Blows up cell by ending hydrophobic effect (Beta)
What is horizontal and vertical transmission?
Horizontal = Person to person Vertical = Mother to fetus/baby(Placenta, breast feeding)
What is meant by portal of entry in regards to a pathogen? 2 Examples?
How Pathogen enters body Mucous membrane (Digestive, respiratory, urogenital tract) Broken skin
What are 4 reasons infectious disease control is more important now than 40 years ago?
populations shift(urban) Travel War New "superbugs"
What are 3 skin infections caused bu streptococcus pyogenes?
(NEI) Necrotizing fasciitis (Superantigen) Erysipelas(Inflames fat) Impetigo(Type 2(ARF Heart) or 3(AGN Kidney) HS) (Most common and involves sequela)
What are three ways we try to control diseases of population?
Destroy reservoir host/vector Quarantine Eradicate pathogen
What are 5 differences between an endo and exotoxin?
1 - Exo=Protein Endo = Lipid A(Part of cell) 2 - Exo=no fever, Endo=Fever 3 - Exo=Transfered using PAI(pathogenicity island) on plasmid Endo=On chromosome 4- Exo-Not heat stable Endo -Heat stable 5 - Exo=can be in toxoid vaccine, Endo=no toxoid
How does gangrene destroy tissue(4 steps)?
1 - Gas released 2 - Inc Pressure 3 - Ischemia from lack of blood flow 4 - Tissue death
What are 4 ways VIRUSES can avoid inactivation by the immune system?
1 - Produce interferon repressors 2 - Coat themselves with LPS and PG from native flora so they're uptaken 3 - Cause cell fusion into syncytia when budding(Memb viruses only) 4 - Produce p53(Tumor supressor gene) inhibitors(Caused by protein not virus integration)
What are 4 at risk groups for pseudomonas infections?
1 - Wounds/Burns 2 - Eye surgery 3 - Cystic Fibrosis 4 - Catheter
Why do strep infections need to be treated quickly(2)?
1 - keep from spreading 2 - Prevent sequellae(Too many antibodies) through penicillin(affects Group A strep)
How does the tetanus toxin function and what type of toxin is it?
A-B Toxin A prevents neuroinbibitors which causes uncontrollable muscle spasms
What type of toxin is anthrax toxin? What are the two major factors that carry this out and what do each do?
A-B toxin Lethal factor - C-c communication Edema factor - Inc fluid secretion
What is the mode of action of superantigen toxins? What is an example
Activates TH cell without antigen present by crosslinking TCR to MHC2 which causes massive T cell activation(Toxic shock) Necrotizing fasciitis (Strep)
Is rubeola(Measles) or rubella(German measles) more dangerous for the following: Adults Children Fetus (Vocab word)
Adults - Rubeola Children - Rubeola Fetus - RUBELLA(birth defects), Congenital rubella syndrome(Ex of vertical trasmission)
What is induced autoimmune disease? What is an example?
Antibodies recognize self as pathogen due to pathogen PAMP being similar to self Rheumatic heart disease caused by Strep M protein
What are the two functions of the proteins of A-B toxin?
B - Binds to receptor (Not toxic) A - Enters cell and carries out toxic fxn
What are 2 things pseudomonas contain that make them difficult to kill?
Biofilms R Plasmids (must use multiple drugs)
What are 2 symptoms of lyme disease?
Bulls eye rash Heart abnormalities
Why does Lyme disease need to be treated?
Causes sequelae - Weird heart rate and arthritis
What is another name for the varicella-zoster virus? What are 2 diseases caused by this?
Chickenpox 1 - Varicella(chickenpox) 2 - Zoster(Shinges) Ex of Latent Virus
What about MRSA makes it difficult to treat? What can we currently do to try?
Contains lots of R plasmids(Many resistance genes) Must decolonize(Can't eradicate) but first must do susceptibility tests to see if antibiotic will work(MIC or Kirby)
What are the 3 types of contact transmission?
Direct - Physical touch Indirect - Person touches fomite(inanimate object) which carries to another person Droplets - Carry about a meter, prevent by distance
Explain the following: Endemic disease Epidemic Pandemic
Endemic - present in reservoir Epidemic - Increase above baseline in reservoir Pandemic - mult continents
What are 4 bacterial disease commonly spread nosocomially?
Enterococcus E. Coli Pseudomonas Staph(MRSA)
What are two types of tissue damaging toxins? Which allows spreading to deep tissue and how
Exfoliative Hyaluronidase - destroys hyaluronic acid which opens up gap between connective tissue
Explain the following routes of transmission: Fecal-Oral Foodborne/waterborne Airborne Vector Borne
Fecal-oral - Fecal mater F/W - 95% of chicken are + for contamination Airborne - Droplet NUCLEI carries org's as far as dust Vector - Mechanical or biological
What are the three disease reservoirs(2nd has vocab), which is impossible to eradicate?
Human - Asymptomatic can carry too! Animal - Can be animal to human(Zoonosis) Environmental - impossible
What causes warts(trasmission?)? How can they be treated?
Human Papillomavirus Contact w or without existing wart Removal or vaccine(Gardasil)
What is the difference between disease incidence and prevalence?
Incidence - New cases Prevalence - New + continuing cases
What is the purpose of MMWR?
Keeps track of daily cases to detect danger of disease
What about Lipid A of gram - bacteria makes it an endotoxin? How does it lead to septic shock?
LPS binds to both CD14 and TLR which induces 4 different cytokine secretion This induces inflammation(Side affect is increase permeability of capillaries) which causes hypovolemia(Blood loss) and septic shock
Why must LPS be detected in injections even after sterilization? What is one method and how do you know if LPS is present?
LPS is released from bacterial death and can be present even if bacteria is dead Limulus Amoebocyte assay(LAL), look for coagulation
How can the varicella-zoster virus be prevented?
MMRV Vaccine
What are 3 supplemental precautions?
Masks(Airborne) Gloves(Contant) Single room(Droplet)
How can measles and german measles be prevented? What are their scientific names
Measles - Rubeola, German measles - Rubella, BOTH can be treated by MMR vaccine
What are 4 reasons that a hospital can facilitate disease spread(Called nosocomial)?
Medical devices Sick people Airborne Health care workers
What are two infections where the main damage is uncontrolled inflammation?
Meningitis Pelvic inflammatory disease
What are 2 reasons disease incidence can vary seasonally?
Mosquito in summer More immunocompromised in winter(Resp viruses)
What can be done to treat gangrene(Trick)?
Nothing Debridement/Amputation prevents spread
How can warts sometimes cause cervical cancer? What are these types?
Papillomavirus has E6 gene that inhibits p53(Tumor suppresor gene), usually E2 gene acts as repressor protein of E6, but provirus form doesn't have this Provirus form(doesn't have E2)
What is meant by portal of exit in regards to a pathogen? 3 examples?
Pathogen leaving to infect other host Dig Tract Resp Tract UG Tract
Which cellulolytic toxin allows bacteria to break out of phagosomes?
Phospholipases
What are 2 symptoms associated with pasteurella infection? What normally carries this(3 types(1 w/out animal))?
Pneumonia Edematous(Swollen) abscess Animals: Fowl cholera(N/A) Shipping fever(cattle) Snuffles(Rabbits)
What is the difference between propagated and common source epidemics?
Propogated - slow onset based on Multiplicity of inf(How many people one person can infect) Common source - Many cases all at once(High, quick peak)
What is the difference between rubeola and rubella?
Rubeola - measles, Dangerous due to Tmem cells being killed leading to secondary infections Rubella - German measles, mild rash
What are 4 skin diseases caused by staphylococcus?
S.Aureus - Causes lesion(furuncle or folliculitis(hair follices), causes toxic shock syndrome (Form biofilms), bullous exfoliation "Frank" S. Epidermis - causes nosocomial infection due to biofilm "Opportunistic"
What is an example of a eradicated disease, what is one that is going to be eradicated soon?
Smallpox Polio soon
How are biofilms involved in infections due to catheters or implants(2)?
Spread due to nosocomial(Hospital infection) and opportunistic(Person in hosp is immuno compromised, usually part of normal flora) Biofilms form persister cells
What is the difference between standard and supplemental precaution?
Standard - assume all body fluids are contaminated Supplemental - for specific routes of transmission
What is the etiology(Cause) of cat scratch disease?
Swelling of lymph nodes due to pyogenic abscess in bite
What is the agent in a tetanus shot, what type of vaccine is this?
Tetanus toxoid (Inactivated vaccine called DTap) Fun fact - Booster is called tatanus immune globulin
What are 3 common fungal skin diseases and the organisms that cause them?
Thrush - Candida albicans Dermatophytes - Ringworm(Tinea) Sporotrichosis - Spore to yeast transformation(Puncture)
How do you prevent airborne transmission?
Use - pressure(Air moves from + to -) to bring air through a HEPA Filter
Why can't you develop a vaccine against Lipid A(Endotoxins)?
Very high heat stability
