BIO 271L Part 2

When is the unknown project due?

August 3rd

What are primary characteristics of bacteria?

morphology, gram reaction, growth pattern

What are the secondary characteristics of bacteria?

metabolic abilities, serology (use of antibodies)

What is Bergey’s Manual?

a classification of bacteria based on similarities in rRNA

What is the largest bodily organ?

Skin

What are some purposes of skin?

keeps us insulated, keeps things out

What are transient microbiota?

temporary microbiota that usually make us sick

What is normal microbiota?

the microbes that are permanently there

What is microbial antagonism?

the normal microbiota prevent the growth of transient microbiota

What are 2 features of skin that help stop the growth of transient microbiota?

Salt from sweat and dryness

What is a portal of entry?

any sort of exposed or open part of the skin that allows bacteria to get into the body

What is symbiosis?

close association between 2 organisms

What are the 4 types of symbiosis?

commensalism, mutualism, parasitism, and competition

What is commensalism?

one organism benefits while the other is unaffected

What is mutualism?

both organisms benefit

What is parasitism?

One organisms benefits while the other is harmed

What is competition?

organisms compete for the same resources in the same space at the same time

Where are the most bacteria on our body?

moist areas like feet, folds, and armpits

What bacteria is dominant on the skin?

Staphylococcus

What are the characteristics of Staphylococcus?

gram positive, produces catalase, facultative anaerobes

What does Staphylococcus aureus produce?

coagulase

What is coagulase?

enzyme that clogs the fibrin in the blood

How many people possess Staphylococcus in their nose?

30%

What is MRSA?

methicillin resistant Staphylococcus aureus

What is bad about MRSA?

it is incredibly resistant to most antibiotics used to treat staph

What is HA-MRSA?

health-care associated MRSA

Where is MRSA usually spread?

through invasive procedures and from healthcare workers not washing their hands before touching patients

Why is MSA good for isolating skin bacteria?

it creates an ideal environment that mimics the skin and it allows us to differentiate between pathogenic (yellow plate, ferments mannitol) and red plate (cannot ferment mannitol)

How is the respiratory tract divided?

Upper and lower respiratory tract

What is included in the upper respiratory tract?

nose, nasal cavity, and throat

What is included in the lower respiratory tract?

larynx, trachea, bronchi, lungs

What are common bacteria found in the throat?

Staphylococcus, Streptococcus, Neisseria, and Haemophilus

Which part of the respiratory system is sterile?

Lower respiratory tract because of cilia escalator constantly pushing up mucus

What is the most widely found bacteria in throat cultures?

Streptococcus

How do we tell between pathogenic and nonpathogenic streptococcus?

testing hemolytic reactions on sheep blood agar

What is sheep blood agar made of?

defibrinated sheep blood and NaCl

What is alpha-hemolysis and what colonies will we see?

partial destruction of blood cells caused by hydrogen peroxide

green cloud around colony

What is beta-hemolysis and what colonies will we see?

complete destruction of blood cells

clearing around the colony

pathogenic organism

What is gamma-hemolysis and what colonies will we see?

blood cells left in tact

no visible change in colony

How do we incubate blood agar?

in a candle jar to create a microaerophilic environment

What is an issue with yeast?

while it is normally present, it can grow out of control and cause infection

How do we observe yeast morphology?

With a simple stain

How do we grow yeast?

We use sabouraud dextrose agar to select for yeast and molds

What is urine?

liquid waste produced by the kidneys, collected in the bladder, and excreted through the urethra

What does transparent/ pale yellow urine mean?

normal

What does clear urine mean?

overhydrated

What does dark yellow urine mean?

dehydration

What does dark orange/brown urine mean?

jaundice

What does pink urine mean?

too many beets

What does green urine mean?

ate asparagus

What does blue urine mean?

ingested methylene blue

What does black urine mean?

melanuria

Is the upper urinary tract sterile?

yes

Is the lower urinary tract sterile?

no

What are the normal microbiota in the lower urinary tract?

mostly gram positive

Are men or women more likely to get a UTI?

women are 30 times more likely

What indicates a UTI?

more than 1000 bacterium from the same species or more than 100 coliforms

How do we prevent UTIs?

hydration, cranberries, vitamin C, and probiotics

How many people did research indicate wash their hands after using public restrooms?

67%

Why should you close your lid when you flush?

Bioaerosols are released

Is MacConkey agar differential or selective?

selective for gram negative, differential for coliforms

How much bacteria is in the large intestine?

10^11 bacteria/ gram of feces

How much of your immune system is influenced by the gut microbiome?

70%

What is a probiotic?

contain live microorganisms, like lactobacillus

What is a prebiotic?

do not contain microorganisms but help feed what is already in the gut

What is good about the appendix?

creates a safehouse for bacteria that can help replenish gut microbiome

What is not good about the appendix?

when it ruptures, the bacteria there could get in other parts of the body and cause severe issues

What kind of bacteria are in the large intestine?

anaerobes and facultative anaerobes

What is the cause of most GI disease?

ingestion of contaminated food or water

Is tomato juice agar selective or differential?

enrichment agar, selective for lactobacillus

How do we incubate tomato juice agar?

in a CO2 jar to create an anaerobic environment

What indicator does TSI slant use?

phenol red

What are the possible results from the TSI slant?

yellow from production of acid, motility of bacteria to the bottom if anaerobic, production of black precipitate from production of hydrogen sulfide, and release of hydrogen gas

What is epidemiology?

Science that deals with when and where diseases occur and how they \n are transmitted in the human population

What are communicable diseases?

diseases spread directly or indirectly from one host to another

What are noncommunicable diseases?

diseases that cannot be transmitted from one host to another

What is an endemic disease?

one that is constantly present in the population

What is an epidemic disease?

when people in a given area acquire a disease in a short period of time

What is a pandemic?

When a disease crosses borders and affects people worldwide in a short period of time

What is droplet infection?

when microorganisms carried on liquid drops from a cough or sneeze cause disease

What is a fomite?

an inanimate object that carries contaminants that cause disease

What are vectors?

insects or other arthropods that carry pathogens

What happens during mechanical transmission?

insects carry a pathogen on their feet and may transfer it to a person’s food

What happens during biological transmission?

the arthropod bites someone

What is a reservoir?

a continual source of an infection

What are carriers?

humans who harbor pathogens but do not exhibit any signs of disease

How do you calculate infection rate?

\#of infected individuals/ population at risk

What is the optimal temperature for growth of psychrophilic bacteria?

15 C or below

What is the optimal temperature for growth of psychrotrophic bacteria?

20-30 C

What is the optimal temperature for growth of mesophilic bacteria?

25-40 C

What is the optimal temperature for growth of thermophilic bacteria?

45-65 C

What is the optimal temperature for growth of hyperthermophilic bacteria?

80 C or above

What are the methods of dry heat?

hot ovens or Bunsen burners

What is the temperature and time for using dry heat to sterilize?

170 C for 2 hours

What are the methods of moist heat?

boiling, pasteurization, and autoclaving

What are the temperatures and times for pasteurization?

63 C for 30 min or 72 C for 15 seconds

What is the temperature and time for boiling?

100 C for 10 min

What are the autoclave numbers?

121 C at 15 psi for 15 minutes

What is ionizing radiation?

X rays and gamma rays, ionize water into highly reactive free radicals that can break strands of DNA

What is nonionizing radiation?

ones essential for biochemical processes