BIMM 120 3

HIV

human immunodeficiency virus

AIDS

caused by HIV (acquired immonodeficiency syndrome)

HIV Stage 1

acute infection with large viral load in blood and very contagious

HIV stage 2

latent period of HIV infection with slow viral reproduction which can appear as asymptomatic

HIV stage 3

causes AIDS due a very damaged immune system which leads to secondary infection and high contagiousness

Ebolavirus

causes ebola and is extremely virulent and causes spread from lymph nodes then to liver spleen which ends in internal bleeding

HPV

human papillomaviruses with no treatment only prevention

Zika virus

most infections are asymptomatic but pregnant women can develop a baby afflicted with microcephally

Malaria

commonly given by Plasmodium Vivax but can cause uncomplicated or severe symptoms and hs 228 million cases a year (quinine or artemisinin treatment)

Malaria life cycle

sporozoites formed in mosquito → mosquito bite → sporozoite migration to liver cells → P. Vivax ruptures blood cells → taken up by msoquito

Exotoxins

proteins secreted by usually gram-positive bacteria which diffuse

Endotoxins

protein complex from the LPS layer of gram negative bacteria which are released through lysis

STEC

Shiga Toxin-Producing E. Coli produces verotoxin causing intestinal/kidney bleeding and bloody diarrhea

EIEC

enteroinvasive E. Coli invades colon which causes watery/bloody diarrhea

ETEC

enterotoxigenic E. Coli produces two enterotoxins but local populations are resistant to them due to the commonality (travelers diarrhea)

EPEC

enteropathogenic E. Coli causes diarrheal disease in infants and children with no toxins

Mycobacterium Tuberculosis

causes tuberculosis which causes granulomas to form in lungs through dead immune cell clumps causing lung tissue destruction

Mycobacterium leprae

incubation period is 5yrs but after that nerve, muscle, and bone atrophy ensues which causes leprosy (treated by bacterial RNA pol inhibitor)

What are leprosy myths?

can't get through casual contact or limbs to fall off or punishment by god

Infectiousness of leprosy?

2 million people are disabled but 95% are immune

Candida albicans

if grows out of control it causes candidiasis which is thrush or a yeast infection (ascomycetes)

Ringworm

fungal species that is spread through skin to skin contact

Principle of Coevolution?

pathogen selectively adapts for less virulent pathogens so that it survives longer

Myxoma virus

introduced via mosquitoes and was extremely virulent but when it mutated to spread between animals its mortality dropped

HA

influenza surface protein that attaches to host cell

NA

influenza surface protein that releases from host cell

How are viruses named?

after their surface proteins HA or NA

How does the immune system recognize viruses?

their surface proteins HA or NA

Mechanism of action of immune cells?

bind to HA or NA proteins which stops spread of the virus

Antigenic drift

over time viral genes encoding HA/NA proteins can mutate which changes the structure allowing for them to pass by immune cells

Antigenic shift

surface antigens are totally different from the parent viruses which lacks recognition from immune cells

Reassortment

dual infection causes two viral genomes to intersect which causes antigenic shift

BSL-3

limited to major clinical centers

BSL-4

associated with government facilities only 50 in the world

HAIs

Nosocomial infections which are spread in hospitals to immunocompromised hosts like infants and elderly

Opportunistic pathogens

causes disease only in the absence of normal host resistance

Staphylococcus aureus

causes toxic shock syndrome due to high exotoxin levels as well as impetigo which is a highly contagious skin infection

Hemolysin

virulence factor that lyse red blood cells

Enterotoxin

virulence factor that is a exotoxin affecting the intestines

Coagulase

virulence factor that is an enzyme that converts fibrinogen to fibrin which clots the area around bacterial cells like a shield

Leukocidin

virulence factor that destroys white blood cells and pus build-up

Pyogenic

virulence factor that results in staph infection (pus forming)

MRSA

methicillin resistant strains that are often hospital acquired due to asymptomatic carriers

Clostridium difficile

opportunistic pathogen that infects a host after dosed with gut bacteria antibiotics (treated by fecal transplant)

Pseudomonas aeruginosa

forms biofilms in lungs of those with cystic fibrosis

Cystic fibrosis

hereditary disease where the body produces excessive mucus that clogs lungs and pancreas

Cerebrospinal Fluid

"tapped" to determine pathogens in liquid tissue which exhibits turbidity

Blood infection test

blood drawn into tubes with growth media and anticoagulant and the incubated in both aerobic and anaerobic conditions but take 3-5 days

Urine infection tests

urine is sampled with a test strip for certain antigens

Specific

ability to recognize a single pathogen

Sensitive

define the smallest quantity of a pathogen than can be detected reduces chances of a "false-negative"

API kit

plastic strip holds twenty wells that detect enzymatic activity

Skin test

injection of an antigen and visual observation of a hypersensitivity

Serological assay

we then take antigens/antibodies and inject them into a blood sample and if there are the opposite present then a coagulated layer will form

EIAs

enzyme immunoassays which are performed with an antibody enzyme complex that reacts when bound to an antigen which will then react to form a color change

Rapid tests

sort of EIA that is performed on paper instead

Food poisoning

toxins from bacteria cause symptoms not the bacteria themselves

Food infection

pathogens in the food and then colonize the gut

Innate immunity

inborn host defense against a range of pathogens

Adaptive immunity

immune response to specific pathogens that has a sort of memory

Phagocytes

neutrophils, macrophages, and monocytes

Innate immunity function

phagocytes engulf and digest pathogens that receive chemokines from innate immunity cells which are signaling molecules

Innate immunity process

bacterial pathogen enters which cause mast cell/macrophages to emit chemokines which cause phagocytes to leave the bloodstream and eat the pathogen

PAMPs

pathogen-associated molecular patterns that phagocytes use to identify pathogens via their proteins, nucleic acids, flagellin, lipids, etc and bind

Phagolysosome

acidic sac of toxic chemicals that is formed from a phage holding sac and a lysosome

Inhibits phagocytes

bacteria produce compounds that neutralize toxins in lysosomes to grow inside them and they die

Inhibits phagocytes

bacteria produce leukocidins which kill phagocytes directly when they are engulfed

Inhibits phagocytes

bacteria have a capsule that prevents being engulfed by phagocytes

Inflammation

what do phagocytic proteins cause so that the tissue will swell and force fluids away from bloodstream

What does fever do?

allows phagocytes to move faster as well as inhibits growth of pathogens and produces transferrins to keep vital iron away

Septic shock

overwhelming immune response from infection induced by full body inflammation

Interferon function

signals cells to destroy RNA and reduce protein synthesis, signals infected cells to undergo apoptosis, and activates immune cells

Interferons will activate

if human body is infected, if viral pathogen has low virulence, or if double-stranded RNA is present

NK function

natural killer cells will detect cells without MHC proteins and release perforin and granzymes to kill them

MHC

major histocompatibility complex is like the molecular signal sequence for healthy cells which goes away if infected

Cytotoxic T cell

uses perforin and made by the thymus gland which and detects infected cell using MHC proteins

Helper T cells

if a phagocyte displays an mal-MHC protein this cell will bind and recruit a cytotoxic T cell or B cells

B cells

derived from bone marrow and make antibodies to target specific pathogens

Antibodies

y shaped proteins that neutralize or mark it for destruction

Memory cells

stores a memory of a pathogen to activate the immune system more readily the next time

Rhizosphere

soil directly around plant roots

BSC

biological soil crusts that primarily inhabit cyanobacteria who convert nitrogen gas to plant available nutrients (nitrogen fixation)

Subsurface

where microbes can live in deep waters at 122 degree anoxic and nutrient depleted environments

Healthy water

high level of oxygen and low level of carbon

Unhealthy water

high level of carbon and low level of oxygen

Eutrophication

occurs when organic carbon and nutrients enter the water which causes bloom of phototrophic and heterotrophic microbes

Open ocean bacteria

less abundant, usually small, and gather nutrients from runoff or upwelling of bottom water

Pelagibacter

high SA and efficient enzymes/genome allows for efficient survival as well as proteorhodopsin which creates ATP out of light

Prochlorophytes

accounts for half of the photosynthetic biomass in tropical regions of the ocean

Trichodesmium

forms puffs which contains up to 200 cells and fixes nitrogen

Rhizobium

mutualistic organism with legumes to nitrogen fix

Endosymbionts

Trichonympha helps termites digest cellulose, Rickettsia produces increased offspring in whiteflies, and Spiroplasma provides protection against a wasp

Aliivibrio fischeri

bioluminescent gram negative bacteria that are housed in bobtail squid

Zooxanthellae

photosynthetic symbiotes with coral