Apr23 M2,3-Introduction to Microbiology and Infectious Diseases Flashcards
divisions in the microbial world
- prokaryotes (bacteria)
- eukaryotes (1. fungi: yeasts, moulds and pneumocystis jiroveci 2. parasites)
- viruses
charact of prokaryotes
- no nucleus
- one free DNA chromosome
- extra-chromosomal DNA (plasmids) (with Abx resistance genes)
- no membrane bound organelles**
morphology of prokaryotes (4 possible shapes)
- coccus (pl. cocci) = spherical
- bacillus (pl. bacilli) = rod shape
- sphirochete (pl. spirochetes) = cork-screw shape
- vibrio (pl. vibriae) = comma shape
possible arrangements of cocci
- alone = coccus
- paired = diplococci
- grouped (cluster) = staphylococci
- in a chain = streptococci
possible arrangements of bacilli + one variant
- circle-elongated shape = coccobacillus
- alone = bacillus
- paired = diplobacilli
- in a chain on long side = palisades
- in a chain (on short side) = streptobacilli
- enlarged rod = fusobacterium
- pear shaped rod = corynebacteriaceae
e.coli location + one function + one disease they cause
- in our intestines
- vitamin K metabolism
- can cause UTIs
spirochetes some examples and special shapes
- treponema pallidum (causes syphilis)
- helicobacter pylori (causes peptic ulcer disease) + has a helical form
- borrelia burgdorferi (causes lyme disease)
vibriae one example
-vibrio cholerae (causes cholerae)
one malaria causing parasite
plasmodium falciparum
organism causing oral thrush and type of organism
- candida albicans
- yeast (single cell fungus, not grouped)
organism causing blue cheese or bread and specific substance produced
- apergillus fumigatus
- mould (fungi cells that group together)
- produces penicillium (so is a penicillin mould)
guinea worm name of parasite and does what
- draculunculus medinensis
- enters through mouth, goes in body, puts eggs, comes out as pimples
eukaryote vs prokaryote vs virus size
eukaryote > prokaryote > virus
how prokaryotes reproduce
- binary fission (no mitosis, asexual)
- clonal expansion
how viruses reproduce
- fission (asexual, use host apparatus to reproduce)
- clonal expansion
how eukaryotes reproduce
- binary fission and clonal expansion for yeasts and some protozoa
- sexual reproduction and NOT clonal expansion + mitosis for animals
bacterial conjugation steps and meaning
- one bacteria sends a pilus to another one
2. the pilus transfers a plasmid to the other bacteria (can transfer Abx resistance this way)
nomenclature of bacteria
- descriptive morphology word used as genus (ex. staph, strep, bacillus, entameoba, salmonella, plasmodium, candida, echinococcus)
- add species
staph pathogenic and non pathogenic one
- staph aureus pathogenic
- staph epidermidis on skin non pathogenic
streptococcus pneumoniae causes what
- pneumonia
- sinusitis
streptococcus pyogenes causes what
- strep throat
- toxic shock syndrome
- pneumonia
- necrotizing fasciitis
bacillus cereus charact
- in rice
- can give foodborne poisoning
entamoeba histolytica is what type of microbe
parasite
plasmodium genus is what
is the group of all the types of malaria (ex plasmodium vivax, plasmodium falciparum, etc.)
candida albicans is what type of microbe
yeast
echinococcus granulosis is what and causes what
- parasite (dog tape worm)
- causes parasite disease in human (echinococcosis or hydatid disease)
nomenclature of viruses
- by family, subfamily, genus and species + genus name
- this family name corresponds to a more common name that is used
influenza is what virus family
orthomyxoviridae
measles virus is what virus
morbillivirus
rabies is what virus family and name
- rhabdoviridae
- lyssavirus
HIV is what virus family
retroviridae
influenza strcture
- 8 RNA chromosomes
- surface hemagglutinins (H) and neuraminidases (N)
- can be type A or type B depending on genetic material (type C not pathogenic in humans)
- specific nomenclature bc many influenza strains
influenza nomenclature
all separated with /
- type (A or B)
- geographic origin
- strain nbr
- year of isolation
- add virus SUBtype in parentheses
ex. A/Fujian/411/2002 (H3N2)
original influenza virus from which many influenza strains are derived
spanish flu (many strains derived from it). initially killed a lot of people but ended up being present normally and balancing with our immunity
microbiote definition
microorganisms in our body + their environment. in skin, mucosal membranes (mouth, vagina), conjunctivae, gut
microbiome def
collective genomes of resident microorganisms in a human body
when do we get colonized by microorganisms and how
right after birth
- baby swallows maternal stool organisms
- baby touches walls of the vagina and the skin
- diff makeup of microbiote if born by C-section
what can influence your microbiote
- Abx use
- living in resource poor countries (more pathogenic organisms)
- environmental contact (ingestion of food, social interactions)
leprosy cause and symptoms
- mycobacterium leprae (bacterium)
- bad skin diseases, destroys peripheral nervous system (lose pain sensation), lose limbs, ulcers
2 dyes used in gram staining and steps
- crystal violet (blue purple)
- add iodine fixor (like KI) to fix the violet
- alcohol or acetone wash
- *add safranin (red pink)
peptidoglycan wall of bacteria what forms it
- molecules called NAG and NAM
- oligopeptides to connect NAGs and NAMs
how bacterial cell wall (peptidoglycan wall) is created)
- penicillin binding protein (cell wall making protein)
- bc if give it penicillin, will pick up penicillin, incorporate it in the wall = weak wall, holes, water in, bacteria bursts
gram positive: bacteria wall and what stains
in to out
- plasma membrane with TM proteins
- THICC peptidoglycan cell wall
* crystal violet will remain bc thicc wall
gram negative: bacteria wall and what stains
in to out
- plasma membrane with TM proteins
- THIN peptidoglycan cell wall
- outer (plasma) membrane MADE OF LPS (LPS is very good at causing fever and shock)
* violet washed bc thin peptidoglycan wall*
* safranin stains peptidoglycan wall*
bacteria ending with ‘‘myces’’ = gram+ or gram-
gram+
(IMP) exceptions to the gram+ rule (some feminine sounding gram POSITIVE bacteria) (3)
gram POSITIVE:
- listeria spp
- nocardia spp
- gemella spp
(IMP) exceptions to the gram- rule (some masculine sounding gram NEGATIVE bacteria) (10)
gram NEGATIVE:
- pseudomonas spp
- aeromonas spp
- haemophilus spp
- acinetobacter spp
- bacteroides spp
- vibrio spp
- enterobacter spp
- citrobacter spp
- campylobacter spp
- proteus spp
some bacteria without cell wall or unstable cell wall + name given to that
atypical (don’t stain well)
- mycoplasma spp (pneumoniae or hominis)
- chlamydia spp (trachomatis, pneumonia, psittaci)
organism that caused the great plague (was a pneumonic plague)
yersinia pestis, gram neg.
- transmitted by flees or rodents
- lives in the gut
defense barriers and adherence mechanisms of bacteria
- capsule (excreted to slip away from phagocytes or opsonization, Abs and WBCs)
- biofilms (gelatin that goes on the whole colony)
- fimbriae (hairy things helping some bacteria to attach to our epithelium)
LPS other name and what it does
endotoxin. leads to immune response
- cytokine release
- fever
- shock
exotoxins (secreted by bacteria) or toxins are what and do what
- proteins
- digest us (bacteria get nutrients)
- local effects on brain, GIT, etc.
- can be superantigens
superantigen definition (like certain toxins are)
- recruits 10% WBCs and 10% of T cell pool
- can lead to shock, necrotizing fasciitis (shock like syndrome)
- binds MHC2 on APC and TCR on T cell no matter the specifity of the TCR and creates interaction. massive T cell activation and IL-2 release
toxin that is an important cause of nosocomial diarrhea (local GI distress) and its organism
shigatoxin (also causes seizures, is a neurotoxin too. IS NOT the toxin causing hamburger disease)
- shigella dysenteriae
- E.coli O157:H7
most lethal toxin in the world
botulinum toxin from Clostridium botulinum
toxins that lead to paralysis: 2 categories
are neurotoxins or respiratory toxins
some neurotoxins
- botulinum toxin (botox): paralysis
- tetanospasmin from Clostridium tetani: tetanus
- shigatoxin: seizures (also cause of nosocomial diarrhea)
some respiratory toxins (cause respiratory distress)
- diphtheria toxin from Corynebacterium diphtheriae (URT illness, obstruction)
- pertussis toxin from B. pertussis (whooping cough, insulin-induced hypoglycemia)
- botulinum toxin (paralytic effect)
- Panton Valentine Leukocidin (PVL) from S.aureus: necrotizing pneumonia
MRSA charact
- methicillin resistant staph aureus
- produces PVL (kills leukocytes, boils on the skin, rupture and leak)
hamburger disease is what
- caused by verotoxin from e.coli O157:H7 infection
- hemolytic uremic syndrome
- bloody diarrhea
listeriolysin O is what
- toxin produced by listeria monocytogenes
- causes lysis of phagosomes (to escape it) and allows IC replication of the bacterium
- allows to evade the immune system
minimum inhibitory concentration definition
-lowest conc. of an Abx needed to inhibit its growth (kill it)
why can we overcome any Abx resistance theoretically but not practically
can kill bacteria with enough Abx BUT depends on toxicity and bioavailability
(IMP) 2 things that can confer resistance to bacteria (2 things resistance genes do)
- resistance gene for an enzyme that cleave Abx
- mutated binding site for the Abx (resistant gene of the protein that used to be a target)
(IMP) other things resistance genes can do
- protein that is a porin that is small enough so that Abx can’t get inside the cell
- protein that pumps Abx out of the cell
mycology (study of fungi): 2 major subdivions of fungi
yeasts (candida spp) and moulds (aspergillus spp and rhizopus spp)
some do both, depending on room temp
fungi cell wall charact (and that are targeted by anti-fungal therapy)
in to out
- phospholipid bilayer with ergosterol instead of cholesterol (which is in animals) as a stabilizer)
- chitin (gives the cell its shape). is a polymer of N-acetylglucosamine (insects, crustaceans, mollusks, squids, octopi also have thant)
main DNA viruses (6)
- herpes virus group (HSV1,2, EBV, CMV, VZV, HHV6,7,8)
- adenovirus
- hepB virus
- HPV
- parvovirus
- poxvirus
main RNA viruses
- hepA and hepC
- rhinoviruses
- measles, mumps, rubella (MMR)
- influenza
- HIV
- enteroviruses (coxsackie, poliovirus, echovirus)
- poliovirus
DNA viruses important charact
stay with us forever (in our genome)
HPV infection consequence
- cervical cancer
- anal and genital warts
- papillomas (warts on fingers and skin)
HIV is what type of virus
retrovirus
why is it that some viruses cause cancer
- integrate in our DNA
- disrupt oncogenes, genes involved in self regulation
some cancer causing viruses
- hepC
- HIV
- EBV
- HPV
- HHV-8 (Kaposi’s sarcoma virus)
malaria (#1 deadliest parasite in the world): what organism and what mosquito + charact
plasmodium falciparum
- anopheles mosquito carries it
- anopheles = 5 antennae + lifts back legs upwards + vertical stance
protozoa def
single cell parasite (plasmodium, entamoeba, dientamoeba, cyclospora, isospora, toxoplasma spps)
some worms
(multi celled parasites)
- nematodes (roundworms) like ascaris spp.
- plathyelminths (flat worms) and flukes like tinea spp, schistosoma spp, echinococcus spp
Jobe’s syndrome
very rare autosomal dominant hyper IgE syndrome
- recurrent cold staph infections
- unusual bad eczema, boils on skin
first vaccine ever done is against what disease
smallpox (gave cowpox in the vaccine)
