Bacteria (DOLT) Flashcards
prokaryote or eukaryote
prokaryote
ways to classify
staining, shape and grouping, oxygen requirements
staining classification
used to make bacteria easier to see under microscope
Gram stain is the most common type of stain
Gram stain
2 stains: 1. deep violet (applied first) 2. red (applied after rinsing process- second stain) makes cell walls more visible two classifications
gram positive bacteria
retain violet colouring
thick cell walls
usually dormant spores in unfavourable conditions
can produce a toxin when reproducing- leads to sepsis and blood poisoning
gram negative bacteria
lose violet colouring during rinsing process
thinner cell walls
classification based on shape and grouping
3 basic shapes: 1. coccus 2. bacillus 3. spirullum basic arrangements of coccus and bacillus: 1. diplo 2. strepto 3. staphylo
coccus shape
spherical or oval
bacillus shape
rod shapped
spirullum shape
spiral shape (usually solitary)
diplo arrangement
paired
group of 2
strpto arrangement
long chain
stphylo arrangement
grape-like cluster
bacillus not defined in this arrangement
classification based on oxygen requirements
most are aerobic
some are faculative anaerobic or obligate anaerobic
autotrophic or heterotrophic
heterotrophic
faculative anaerobic
grow better without oxygen but can survive with it
aerobic
rely on environment containing oxygen
obligate anaerobic
cannot survive in the presence of oxygen
repreoduction
most use binary fission
grow larger and larger until single chromosome is duplicated and divides into two cells
can reproduce every 20 minutes
conjugation
genetic material is exchanged between 2 bacteria cells
involves pili and plasmids
conjugation process
- donor cell and recipient cell connect a pilus to form a tube
- double stranded plasmid from donor cell seperates
- one strand of plasmid from donor cell enters recipient cell and remains in donor cell
- DNA replicates to create double stranded plasmids in both cells
antibiotic resistance
genes from plasmid integrated into chromosome
coming into contact with harmful bacteria
through improper handling or under-cooked food
Escherichia coli (E. coli)
found in intestines of some mammals (including humans)
synthesizes vitamin K and controlling other disease causing bacteria
some types can infect humans
found in contaminated water, under-cooked ground meat and unwashed produce
Symptoms of E. coli
nausea, diarrhea, abdominal cramps
symptoms show 2-5 days after exposure and can last for weeks
severe cases can cause kidney failure and death
young, elderly, and people who have compromised immune systems are more likely to develop serious cases
“hamburger disease”
nickname of E. coli because of its association with round meat
outbreak of E. coli
2002
Walkerton, ON
2,500 people infected
7 deaths
Salmonela
found in raw or under-cooked chicken, eggs, and some dairy
preventing salmonela
separate meat cutting board
washing hands and anything that comes into contact with raw meat
symptoms of salmonela
diarrhea, stomach pain, chills, nausea, headaches
appear 6-24 hours after exposure
lasts 1-2 days
Staphylococus
found on human skin
spread through improper hand washing
symptoms of staphylococcus
nausea, diarrhea, vomiting
symptoms show 1-6 hours after exposure
risk of severe dehydration
Listeria
found in processed meat and dairy products
reproduces slowly in fridge
symptoms of listeria
similar to other kinds of food poisoning
serious cases can cause miscarriages or meningitis
symptoms appear soon after digestion-3 weeks after
Clostridium botulism
most serious and uncommon form of food poisoning
affects nervous system
common name- botulism
found in improperly canned processed foods in air tight containers
symptoms of botulism
blurred vision, difficulty speaking, swallowing, and breathing
symptoms appear 4hrs-1 week after ingestion
fatal if not treated immediately
necrotizing facscitis
medical term for flesh eating bacteria
bacteria infects deep layers of skin and muscle, spreading along fascia
fascia- connective tissue around muscles
not common
spreads very quickly- amputation is sometimes required
can be caused by a type of streptococcus
necrotizing
dead or dying tissue
facscitis
inflammation of the fascia
tetanus
same genus as botulism
soil bacteria
not caused by rust
symptoms of tetanus
paralysis (often in jaw muscles)
can affect all muscles with spasms that becomes painful
uses for bacteria
bacteria function as decomposers- break down dead organisms into nutrients other organisms can use
nutrient cycles rely on bacteria
ex. carbon and nitrogen cycle
good bacteria in food
living cultures of bacteria are used to change milk into yogurt
some brands of yogurt contain living bacteria “pro-biotics” that help the intestines and control harmful bacteria
turning alcohol into vinegar
producing some cheeses, sauerkraut, pickles
recombinant DNA- plasmid of a bacteria cell can be used as vector that transfers DNA
used to treat diabetes and dwarfism
treating diabetes
human gene for producing insulin incorporated into a plasmid and passes it along during conjugation
binary fission creates a lot of insulin as the insulin gene continues to be passed on
controlling bacteria
proper handwashing (best way), disinfectants, antiseptics, antibiotics, sulfa drugs
disinfectants
kill bacteria on non-living surfaces
create an unfavourable environment
antiseptics
kill bacteria and prevent spread on living tissue
not as strong or toxic as disinfectants
antibiotics
kill bacteria inside the body
only harm bacteria
works in a number of different ways:
-disabling bacteria’s reproductive mechanisms
-preventing cell wall growth
-preventing bacteria from turning food into energy
penicillin
first antibiotic ever discovered
discovered in 1928 by Sir Alexander Fleming
based on mold speck’s on bacteria
purified and accessible to patients in the 1940s
used to treat bacterial infections
molds and antibiotics
different molds lead to the development of different antibiotics
modern antibiotics
most are synthetic
slight structural changes are made to improve effectiveness
allergic reactions to antibiotics
mild-severe
symptoms: itchy, red hives, swelling, coughing, wheezing, difficulty breathing
any reaction means the patient can not use the antibiotic again due to risk of next reaction being worse
sulfa drugs
synthetic
first sulfa drug was a red dye
most work by blocking bacteria from synthesizing folic acid and vitamin B9
bacteria die without vitamin B9
must drink a lot of water with these drugs
proper use of antibiotics and sulfa drugs
take exactly as prescribed: -length of time -time of day -number of times a day -with or without food -consumption of alcohol notify doctor of any other medications you are taking and history of allergic reactions to drugs
using antibiotics
stored in a dark, dry place
some must be refrigerated
don’t take someone else’s
only use them if necessary
