introductiontomicro Flashcards
what is a pathogen
any microorganism that can cause a disease
virulence
the ability of a microorganism to cause a disease
what are some ways to identify bacteria samples
microscopy, detection of bacterial antigents, detenction of bacterial nucleic acids, culture, detection of antibody response to bacteria
what are four fundametal features of classification of bacteria
visible features, nutrition, end product, and surface molecules
what are common shapes for bacteria
cocci shpricile, bqacilli rod or striaght or curved, and spirochetes spiral
what is the diffence between a gram positive and gram negative
thick layer peptidoglycan for gram positive and thin for negative with a outer membrane and periplasmic space.
what are the steps for gram staining
add crystal violet, then add gram iodine, then decolorizer such as alcohol or acetone, then add safranin red purple is for positive.
describe the structure of peptidoglycan
NAG n-acytalglucosamine and NAM n-acectylmuamuc and has Beta 1,4 linked NAG and NAM and tears and saliva contain a lysozyme that will break this beta 1-4 link apart
what are the effects of peptioglycan in our bodies
it has a pro inflamatory reaction and will trigger the TNF production.
what acids are found in gram positive bactieria and not gram negative
.it contains techoic acid and Lipoteichoic acid or LTA and they promot attachemts to other bacteria and to host cells with the LTA binding to the bacterial membrane and are important virulence factors.
what is the outer membrane of a gram negative bacteria covered in
porin for transport of nutrients and lipopolysaccharides LPS which makes a stiff canvas staff maintains structure and permeability barrier.
what does LPS or lipopolysaccharide do to the body
too much leads to spetic shock, massive inflammatory reaction, it has three portion LIPID A portion makes it endotoxic leading to septic shock they have fatty acids that anchor it to the outer membrane. CORE POLYSACCHARODE is reuired for bacteria strructure and viability and O ANTIGEN important in identification of bacteria
how does LPS cause inflammation
binds to CD 14 and TLRr4 on phagocytes antigen presenting cells activate the immune system and causes septic shock with TNF IL1 snd IL6
what are acid fast bacteria
they have very complex cel envelope that is waxy because of mycolic acids bound to the peptidoglycan via a polysaccharide,
how do you stain an acid fast stain
saint red by carbol fuschin then acid alcohol destain and methylene blue use to counter stain an label other bacteria
what is unique to acid fast structure
lipoarabinomannan LAM related to LPS and acts the same, arabinogalactans bind the the mycolic acid, and mycolidc acid.
what are pili or fimbrae
tube with a small hollow core, found on positive and negative, have two function attachment through common or somatic and gene transfer through sex pilli
what is a flagella
used to move, different types , polar one pole, lophotrichous multiple at a single pole, amphitrichous both poles, and peritrichous all aroun the bacteria
what is another name for the antigen of flagella
H anitigen
what is the capsule of bacteria
almost always polysaccharide, protects bacteria and virulence factor, protects from immune system antiphagocytic
what is a biofilm
a organized community of microbials that creates a capsule over the entire population
what is the quellung reaction
used to identify encapsulated bacteria will make it visible swell.
what are endospors
only gram positve will make and only some of them. The bacteria will form a dorment state with the minimum RNA and organells and rest until favorable condition occure where it will reactivate. The location of the spore will aid in identification.
what are the characteristics of endospores
contain a complete copy of chromosones minimunm proteins and ribosomes, contains high concentration of calcium bound dipicolinc acid
