MCRO 251 Exam #1 Organisms Random

Giardia lamblia reservoir

animal reservoir

Giardia lamblia transmission

water-borne (consumption of contaminated water)

direct contact (sexual or fecal-oral)

Giardia lamblia incubation period

6-20 days

Giardia lamblia ID50

10 cysts needed to infect

Giardia lamblia at risk populations

people who are often outdoors, those who work around feces, people with poor hygiene

Giardia lamblia infection process

- cysts are ingested

- trophozoites emerge from cysts in small intestine, some attach to epithelium of intestines and some move around intestinal mucus

- trophozoites disrupt intestinal tract causing signs and symptoms then are carried to large intestine

- some trophozoites turn back into cysts eliminated in feces

- remaining trophozoites are eliminated through diarrhea

Giardia lamblia prevention

good hygiene, filter/boil/disinfect water before drinking

Giardia lamblia treatment

no treatment required for mild cases, medication can be provided in more extreme cases

NO vaccine

Giardia lamblia bacterial morphology

- flagellated protozoan

- shaped like a pear

- two side by side nuclei (eyes)

- cysts have thick chitin cell walls to protect from environment

- lacks mitochondria, have mitosomes

Giardia lamblia signs and symptoms

giarrhea, gas, vomiting, fatigue, weight loss, abdominal cramps, indigestion, nausea

Giardia lamblia virulence factors

- trophozoite form: growing and feeding

- cyst form: dormant

trophozoites multiply in intestinal tract

- trophozoites cannot survive in environment

- cysts are only infectious form because can live in stomach acid

- trophozoites emerge from cysts in intestines

Rabies reservoir

animal reservoir

Rabies transmission

direct contact transmission (bite from an animal with rabies)

Rabies incubation period

2-3 monthhs

Rabies at risk populations

people around wild animals or in outside environments, those who have been around/bitten by an animal with rabies

Rabies infection process

- rabies virus is introduced to the body

- virus multiplies at infection site

- virus enters sensory neurons

- uses retrograde transport to move to axon of neurons in spinal cord

- virus eventually travels to brain where it reproduces rapidly with negri bodies

- rabies spreads downward from brain to rest of body

Rabies prevention

not possible without eliminating animal host, vaccination of cats and dogs in America has decreased rabies cases, avoid animals suspected to be infected with rabies

Rabies treatment

wash wound, apply antispeti, PEP-human rabies immune globulin injected, four injections. of rabies vaccines, no treatments once symptoms cured

Rabies vaccine

vaccines for animals

Rabies viral morphology

- single-srtanded RNA

- bullet shaped

Rabies signs and symptoms

fever, headache, muscle aches, severe sore throat, fatigue, agitation, confusion, hallucinations, seizures

Rabies virulence factors

- forms negri bodies in brain tissue

- envelope virus

Klebsiella pneumoniae reservoir

human reservoir in intestinal tract

Klebsiella pneumoniae transmission

direct contact/person to person

Klebsiella pneumoniae incubation period

1-3 days

Klebsiella pneumoniae at risk populations

people that are very young, very old or have compromised immune systems, most common in healthcare

Klebsiella pneumoniae infection process

- organism colonized throat

- gains access to lungs via inhaled air or mucus

- produces capsule and specific siderophore that allows it to steal elements (iron) from host cell

- depletion of iron causes cellular stress and inflammation which increases spread of bacteria

- causes tissue damage and rapid formation of lung abscesses

- can spread to bloodstream, liver, brain, and other tissues causing abscesses and septic shock

Klebsiella pneumoniae prevention

- Disinfection of environment

- Use of sterile respiratory equipment

- only using antibiotics when necessary

- healthcare workers follow infection control measures

Klebsiella pneumoniae treatment

treated with antibiotics (although increasing resistance to antibiotics occurring), surgery for abscesses

Klebsiella pneumoniae vaccine

none

Klebsiella pneumoniae bacterial morphology

enterobacteria, gram-negative, rod shaped, different strains can be more infectious

Klebsiella pneumoniae signs and symptoms

cough, chills, shortness of breath, fever, chest pain, cyanosis; thick, bloody, jelly-like sputum

Klebsiella pneumoniae virulence factors

- large capsule can produce pilli

- produces large mucoid colonies

- part of normal microbiota of intestinal tract

- found in mouth and throat

- produces siderophores that cause iron depletion which increases spread of bacteria via inflammation

- becoming resistant to antibiotics via plasmids

- lipid A cell wall

Rickettsia rickettsii reservoir

animal reservoir (tick --> humans)

Rickettsia rickettsii transmission

biological vector / arthropod-borne

(wood and dog tick bite - zoonosis)

Rickettsia rickettsii incubation period

3-12 days

Rickettsia rickettsii at risk populations

people who live in areas with ticks, outdoors frequently

Rickettsia rickettsii infection process

- tick infects host through bite

- tick bite releases RMSF into blood stream

- RMSF engulfed by vessel and endothelial cells where it multiplies

- propels into adjacent host cells, infecting more

- host cell becomes so damaged that the cell ruptures

- RMSF bacteria released into blood stream and infects more cells

Rickettsia rickettsii prevention

avoid tick-infested areas, wear protective clothing, use tick repellent, inspect body for ticks after being outside, remove attached ticks (with out crushing them), remove tick before 10 hours has passed

Rickettsia rickettsii treatment

antibiotic doxycycline, treat bite area with antiseptic

Rickettsia rickettsii vaccine

none

Rickettsia rickettsii bacterial morphology

- non-motile

- coccobacillus

- obligate intra cellular bacterium

- gram-negative cell wall

Rickettsia rickettsii signs and symptoms

headache, fever **in the SUMMER, pains in muscles and joints, rash on wrists and ankles that spreads to palm then limbs, decreased blood sugar, inflammations blood vessels (vasculitis), blood clotting and necrosis

Rickettsia rickettsii virulence factors

- bacteria transmitted after 4 - 10 hours of feeding

- require host cells therefore difficult to grow in culture

- invade and destroy host cell to spread to more

- endotoxin (lipid A component of cell wall)

- actin tail

SARS-CoV-2 reservoir

zoonosis (origin) bats

now = primarily human

SARS-CoV-2 incubation period

2-14 days

SARS-CoV-2 transmission

direct, droplet nuclei

SARS-CoV-2 viral morphology

gram negative, RNA virus, enveloped, surface viral proteins, spherical form

SARS-CoV-2 signs and symptoms

fever, cough, aches, cold, respiratory distress

SARS-CoV-2 virulence factors

spike proteins (protrude from viral envelope), rapidly mutate

SARS-CoV-2 prevention

was hands (wash away envelope, kill virus), vaccinate, masks

SARS-CoV-2 at risk populations

people with respiratory diseases (Ace-2 receptors in lungs), elderly, children, high blood pressure/cardiac problemspeople with respiratory diseases (Ace-2 receptors in lungs), elderly, children, high blood pressure/cardiac problems

SARS-CoV-2 vaccine

yes

Staphylococcus aureus reservoir

human reservoir

Staphylococcus aureus ID50

low? unsure

Staphylococcus aureus incubation period

n/a

Staphylococcus aureus transmission

MAINLY fomites, or direct transmission by touch

Staphylococcus aureus morphology

- gram positive cocci in clusters "grape like"

- encapsulated

- RNA/DNA

Staphylococcus aureus at risk populations

most people are carriers

Staphylococcus aureus signs and symptoms

small red bumps or pimples that could progress into furuncles or carbuncles with swelling, pus, redness, tenderness, fever

Staphylococcus aureus virulence factors

CAPSULE, CLUMPING FACTOR, COAGULASE

bacteria enter hair follicle to cause inflammatory response, follicle is plugged and bacteria enter subcutaneous tissue

Staphylococcus aureus prevention

Hand washing, wound cleansing, sterilization of used gloves, cleaning surfaces, sanitization

Staphylococcus aureus treatment

antibiotics, sometimes surgery to drain pus

Staphylococcus aureus vaccine?

no

Streptococcus pneumoniae reservoir

humans

Streptococcus pneumoniae incubation period

1-3 days (short)

Streptococcus pneumoniae transmission

respiratory droplets

Streptococcus pneumoniae at risk populations

ELDERLY ARE AT RISK; alcoholism, narcotic use, viral infections, chronic heart/lung disease, diabetes, cancer

Streptococcus pneumoniae morphology

- gram positive diplococcus

- lancet shaped

- encapsulated

- RNA

Streptococcus pneumoniae signs and symptoms

Cough, sudden chills and fever, shortness of breath, chest pain, cyanosis, rust-colored sputum from blood

Bacteremia can be a complication that occurs

Streptococcus pneumoniae virulence factors

Capsule that prevents destruction during phagocytosis

- IgA protease lyses IgA antibodies

- bacteria adherence

Streptococcus pneumoniae prevention

hand washing

Streptococcus pneumoniae vaccine?

yes

Streptococcus pneumoniae treatment

antibiotics

Clostridium tetani reservoir

humans, environmental (soil), animals

Clostridium tetani incubation period

can range from 3-21 days

Clostridium tetani transmission

endospores: introduced through wound, fomites, water

Clostridium tetani at risk populations

people near rusty nails a lot

Clostridium tetani morphology

- drumstick shape

- anaerobic spore-forming

- gram-positive rod

Clostridium tetani signs and symptoms

Jaw cramping, sudden tightness or movement of muscles, trouble swallowing, seizures, headache, fever/sweating, muscle pain/spasm in jaw, abdomen, back or entire body

Clostridium tetani virulence factors

Exotoxins: tetanolysin and tetanospasmin (AB toxin)

Results in an extended muscle contraction bc there is no inhibitory interneurons

Toxins carried to brain/spinal cord via motor nerves or blood

Enters through a wound

Clostridium tetani prevention

vaccine/boosters

Clostridium tetani virulence factors vaccine?

Yes

Clostridium tetani treatment

antibiotics, tetanus immune globulin

HPV organism

virus

HPV ID50

only 1 touch can cause spread

HPV transmission

touch, sex, direct contact

HPV populations

people who are highly sexually active

HPV prevention

use condoms, get tested for STIs, don't F around

HPV signs & symptoms

itchy skin

pain

warts

tumors

often asymptomatic & can cause lots of different cancers; chronic infection

staphylococcus aureus SSSS organism

bacteria

staphylococcus aureus SSSS disease reservoir

humans and animals

staphylococcus aureus SSSS disease incubation period

short

staphylococcus aureus SSSS disease at risk population

infants

staphylococcus aureus SSSS disease treatment

penicillinase-resistant penicillins

removal of dead tissue

isolate patient

staphylococcus aureus SSSS disease prevention

avoid contact

staphylococcus aureus SSSS disease morphology

gram positive

staphylococcus aureus SSSS disease virulence factors

exfoliation: toxin that destroys material that binds outer layers of epidermis together, causing syndrome

toxins, immune-modulatory factors, exoenzymes

staphylococcus aureus SSSS disease signs & symptoms

sensitive red rash with sandpaper texture

malaise

irritability

fever

large blisters

peeling of skin

staphylococcus aureus SSSS disease transmission

direct, touch