what are the four virulence factors of neisseria meningitidis?
polysaccharide capsule, LPS endotoxin, pilli (for attaching to resp. mucosa), and IgA protease (so its pilli can do its job)
what does the vaccine to n. meningitidis include?
polysaccharide capsule and peptide conjugated to it
which bugs have heat killed bacteria in their vaccines?
bordatella pertussis, vibrio cholera, and yersinia pestis
what is the BCG vaccine used for? what does it contain?
TB; contains LIVE organisms (attenuated) of different myocbacterium
Other than TB, which bugs use live attenuated organisms in their vaccines?
salmonella typhi and francisella tularensis
what is the cell wall of bacteria made of ? which bacteria have it- gram negative or positive?
peptidoglycan (sugar backbone crosslinked by peptide side chains); both
what is the purpose of the cell wall in bacteria?
protect against osmotic pressure and give rigid support
what is the major cell antigen for gram positive bacteria? where is it found?
teichoic acid; both in the cell wall and cell membrane
what is the major cell antigen for gram negatives? where is it found?
polysaccharid "O" found in the Lipopolysaccharide (LPS) in the outer membrane
what is Lipid A and where is it found?
it induces TNF and IL 1 and is found in the gram negative cell wall LPS (lipopolysaccharide- the lipo part)
what does the plasma membrane of bacteria have? what occurs there?
site of oxidative and transport enzymes (including peptidotransferase)
what does a capsule provide? what bacteria is the exception to the rule that capsules are made out of polysaccaride? how does the immune system get rid of bacteria with capsules?
protection from phagocytosis; bacillus anthracis- D glutamate; opsonization and when gets filtered in spleen then fixed macrophages attack
T/F the flagellum provide adherence to cell surfaces and attachment for conjugation
false; the pilus/fimbriae do
which is longer the pilus or the flagellum? which is made out of glycoprotein? which only protein?
flagellum; pilus; flagellum
which bacteria has flagella that are periplasmic? are the gram negative or positive? what is required to visualize one of these species?
spirochetes; gram negative; dark field microscopy for treponema
what is the spore made of? what does it protect the bacteria from?
keratin like coat made of dipicolinic acid; dehydration, heat and chemicals
what is a glycocalyx? what is it made of? what does it help bacteria with?
a biofilm; polysaccharide; foreign surfaces
what is the prototypical bacteria that uses a glycocalyx capsule for a biofilm formation? is it streptococcus or staphylococcus?
s. epidermitis; staphyloccus
which bacteria do not gram stain well?
intracellular: chlymadia, rickettsia, legionella (fac);no cell wall: mycoplasma; too much lipid: mycobacteria; too small: treponema
other than dark field microscopy , what else can be used to confirm treponema presence?
flourescent antibody staining
other than being intracellular, what else makes it difficult to gram stain chlymadia?
lack muramic acid in cell wall
what does PAS stand for? what is it? what does it visualize?
period acid schiff; a special stain to visualize to certain bugs and glycogen and mucopolysaccharides
What is Ziehl Neelsen? what is it used for?
a stain; to visualize acid fast organisms (mycobacterium, nocardia, cryptosporidium)
What is India ink? what is it used for?
a special stain; to visualize encapsulated organisms (not just bacteria- cryptococcus neoformans also!)
what is mucicarmine? what is it used for?
a stain; also can stain capsules (turns red) (and adenocarcinomas)
what special culture requirement is needed for H. influenzae? with what factors? what bug can provide what factor?
Chocolate agar with factors V and X (NAD+ and hematin); s. aureus can provide V (NAD+)
What special stain is needed for N. gonorrhea? what is in it?
Thayer_martin media aka VPN (vanc, polymyxin, nystatin)
what special culture requirements are necessary for Corynebacterium diptheriae?
tellurite plate (potassium); lofflers media
what special culture requirements are required for mycobacterium tuberculosis?
What culture is required for lactose fermenting enterics? what color does the agar turn?
MacConkeys agar; pink
other than Macconkeys agar, what else can be used to culture E. coli? what color does the agar turn?
Eosin Methylene Blue (EMB); blue black
what special culture requirement is needed for legionella?
charcoal yeast buffered with cysteine and iron
what determines whether a bug is anaerobic or aerobic?
whether it has enzymes like catalase or superoxide dismutase to deal with O2 FR
which are the obligate aerobes?
mycobacterium tuberculosis, pseudomonas aeruginosa, nocardia, bacillus cereus
what are some characteristics of obligate anaerobes? what drugs can they can not be used for these bugs?
produce gas in tissue CO2 and H2 (crepitus) and generally foul smelling (d/t short chain fatty acids) and are difficult to culture; aminoglycosides because they require O2 to enter cells
why are rickettsia and chlymadia obligate intracellular? what age group do they have the worst presentation in and why?
because cant make own ATP; neonatal because require cell mediated immunity
what are the facultative intracellular bacteria? why is this property considered a virulence factor?
salmonella, legionella, neisseria, brucella, mycobacterium, listeria, francisella; because can evade immune system by living unnoticed inside cells
what are the classical examples of encapsulated bacteria? what reaction is used to visualize them? why are they very virulent to asplenic patients?
N. meningitidis, S. pneumonia, H. influenzae, Klebsiella pneumoniae, Salmonella, group B S. agalacteiae; quellung reaction- Ab binds to capsule and then swells; because the way to overcome this virulence factor is to opsonize them where the spleen then phagocytoses them
T/F N. gonorrhea does not have capsule is not a facultative intracellular
false! it is a fac. intracellular (but no capsule)
what is the antigen used for encapsulated organism vaccines?
the capsule conjugated to a peptide (diptheriae toxoid!)
Why are vaccines conjugated to a protein? If not, what would happen?
to activate the T system and then B cell class switching; only IgM antibodies would be produced because T cells dont recognize only the polysaccharide
what four bugs are urease positive? what kind of environment do they create? how?
H. pylori, Ureaplasma, Klebsiella, Proteus; alkaline environment; by splitting urea to make ammonium
what are the four pigment producing bacteria? what colors?
actinomyces- yellow sulfur granules; s. aureus- yellow pigment; pseudomonas- blue green pigment; serratia- red
what other virulence factor (other than capsule) evades phagocytosis? what bug has this?
protein A by binding Fc region of Ig- prevents both phagocytosis and opsonization; S. aureus
what is an IgA protease? what bugs have it? what does it allow?
it cleaves secretory IgA (dimer) so that pili can bind to mucosal surfaces or bug can generally colonize it; Neisseria, S. pneumonia, H. influenzae type B
which bacteria has the virulence factor "M" protein? and what does it do?
group A streptococcus; helps prevent phagocytosis
which gram positive bacteria also has endotoxin? what other virulence factor does this bacteria have?
listeria monocytogenes; fac. intracellular
T/F Endotoxin is more antigenic than exotoxin
False. high titer antibodies called antitoxins are induced in exotoxins; endotoxin in poorly antigenic (some TLR bind to it)
what is the exception to the rule that exotoxins are destroyed rapidly at 60?
staph aureus enterotoxin
what is a superantigen? what two bugs use them?
its an exotoxin that binds directly to MHC II and T cell receptor simultaneously crosslinking to activate large numbers of CD4 th2 cells to release massive amounts of IFN gamma and IL2
what is scarlet fever? what bug causes it and how?
toxic shock like syndrome caused by s. pyogenes by secreting erythrogenic toxin
what are ADP ribosylating toxins?
they interfere with the host cells function; the B component binds to a receptor on the surface of the cell which enables endocytosis- A comp then attaches an ADP ribosyl to a host cell protein (ADP ribosylation) which alters the host cells function
What is exotoxin A? which two bugs have it?
It is an ADP ribosylating AB toxin that inactivates EF 2; Corynebacterium diptheriae and Pseudomonas Aeurginosa
what type of exotoxin does Vibrio cholera have? what does it do? what toxins are similar?
ADP ribosylating AB exotoxin; ADP ribosylation of Gs protein which activates adenylyl cyclase which increase pumping of CL out into gut (and decrease NA reabsorption) [upregulates CFTR]; ST and LT of ETEC
What type of exotoxin does E. Coli have? what do they do? how are they different?
both are ADP ribosylation AB exotoxins: heat labile exotoxin stimulates adenylate cyclase and heat stable stimulate guanine cyclase
what type of exotoxin does bordetella pertussis secrete? what does it do?
ADP ribosylation AB exotoxin; inhibits G alpha inhibitor resulting in increase of cAMP which causes an inhibition of chemokine receptor causing lymphocytosis (no neutrophils or macrophages come)
what type of toxin does clostridium perfringens have? what does it do?
alpha toxin exotoxin; a lecithinase that acts as a phospholipase to cleave cell membrane and cause gas gangrene
what type of hemolysis does the alpha toxin of clostridium perfringens do on blood agar?
double zone! (d/t alpha toxin lecithinase that acts as a phospholipase)
what type of toxin does clostridium tetani release?
an exotoxin that blocks the release of GABA and glycine (inhibitory neurotransmitters) in Renshaw interneurons which causes lockjaw
what type of toxin does clostridium botulinum release?
an exotoxin that blocks the release of acetylcholine and causes anticholinergic symptoms, CNS paralysis, especially in cranial nerves (ptosis, difficulty swallowing)
what type of exotoxin does Clostridium dificile have?
ADP ribosylation AB toxin- A toxin results in actin depolymerization and loss of cytoskeletal structure- cytotoxicity and necrosis
what type of toxin does bacillus anthracis have?
exotoxins that are called "edema factor" and "lethal factor"; edema factor causes edema because it is a bacterial adenylase cyclase itself; lethal cactor causes an increase in TNF alpha and IL 1
what kind of toxin does Shigella have? what other bacteria secretes this toxin?
exotoxin that cleaves host cell rRNA 60S and enhances cytokine release; molecular mimicry can result in HUS; E. coli O157:H7
What type of exotoxin does group A s. pyogenes have?
streptolysin O is a hemolysin and the antigen for ASO antibody, which is used for diagnosis of rheumatic fever
what are the five camp inducers? how do they do it?
vibrio Cholera (by ADP ribosylating Gs), bacillus anthracis (exotoxin is a bacterial adenyly cyclase itself), e.coli heat labile toxin (activates adenylyl cyclase), pertussis exotoxin inhibits Gi causing Whooping cough and lymphocytosis by inhibiting chemokine receptors
other than S. epidermitis on prosthetic valves, what other bacteria forms biofilms?
P. aeuriginosa in CF patients in respiratory system
what are three actions of lipid A of endotoxin?
1) activates macrophages: IL1, TNF, NO
2) activates complement via alternate pathway: C3a (hypotension and edema), C5a (neutrophil chemotaxis)
3) activates Hageman factor (coagulation cascade activator and DIC)
what is the stationary phase in bacterial growth curve?
nutrient depletion slows growth or spore formation
what is the death phase in the bacterial growth curve?
prolonged nutrient depletion and building of waste products lead to death
what does it mean for a bacteria to be "competent"?
it means it can take part in transformation- or it has the membrane proteins that allow it to take up DNA of the same species from the enviroment
in F+x F-conjugation, which is the F+ plasmid? can more than the plasmid DNa get transferred in this type of conjugation
the one that contains the genes required for the conjugation process; Plasmid DNA is the only thing that is transferred
what is the difference between Hfr x F- conjugation and F+ x F-?
in the former, F+ plasmid can become incorporated into bacterial chromosomal DNA, replication of incorporated plasmid DNA may include some flanking chromosomal DNA and the so the next transfer may include plasmid and chrom genes
what is transposition?
segment of DNA gets excised and reincorporated from one location to another- from plasmid to chrom for ex.
T/F transposition is a way that chrom genes are transmitted from one bacteria to another
true- excision of chrom DNA can jump into plasmidal DNA and then transferred into another bacterium
other than staph. epidermitis and pseudomonas aer. what else can form biofilms? on what?
systemic candidiasis on IV, catheters, peritoneal dialysis
what are neutropenic patients (and thus CGD patients) really susceptible to?
candidiasis and aspergillosis (and the other opportunistic fungi) and staphylococcus
what is the nucleocapsid shape of DNA viruses? what is the exception?
icosahedral; POX virus (complex)
what is the surface protein made of on viruses? where is it located?
glycoprotein (usually pulled from membrane they burst out of!); the envelope
what is the only virus that doesnt have an envelope from a plasma membrane? where is it from?
herpesviridae family; nuclear membrane
what is recombination?
a form of viral genetics between two chromosomes by crossing over within regions of base sequence homology
what is reassortment?
a form of viral genetics between two viruses with segmented genomes- they exchange segments and is a form of high frequency recombination
what is complementation?
a form of viral genetics; when one virus in a cell has a defunct protein and another virus comes in and saves it with its own protein that serves both viruses
what the phenotypic mixing?
a form of viral genetics when two viruses infect the same cell and one virus' genes is covered in another virus' surface proteins- the result is that the virus genes are taken to a place it usually doesnt go (to whereever the glycoproteins of the other virus directed to)
what are the live attenuated viral vaccines?
Sabin's polio, adeno, small pox, yellow fever, chickenpox (VZV), MMR
what is the only live attenuated vaccine you can give to HIV positive patients? can you give it to pregnant women?
what is the difference in immunity induced between a live attenuated and a killed vaccine?
live attenuated make both humoral and cell mediated immunity whereas killed vaccines only make humoral
what is the drawback to live attenuated vaccines?
they are dangerous to give to immunocompromised because they chance to revert to virulence (killed vaccines are stable)
which RNA viruses are double stranded?
retroviridae, Togavirus, Flaviviruses, corona , hep E virus, calicivirus, picornavirus
are naked nucleic acids of (-) ssRNA viruses infectious? how about naked dsRNA nucleic acids of viruses?
no; no; they require enzymes in complete virion
are naked nucleic acids of +ssRNA and dsDNA viruses infectious? what are the exceptions?
yes; POX and HBV
T/F all viruses are haploid
FAlse- all are except retroviruses which have 2 identical ssRNA molecules
which viruses are naked? ie no envelope?
Naked CPR PAPP: Calicivirus, Picornavirus, Reovirus, Parvovirus, Adenovirus, Papilloma, and Polyoma
what is the exception the rule that viruses get their envelopes from the plasma membranes they lyse out of?
herpes family gets it from the nuclear membrane they leave out of
what are the enveloped RNA viruses?
Influenza (orthomyxo), Paramyxofamily, Toga, Rhabdo and Retroviruses
what are the negative stranded viruses? what do they need to replicate?
Always Bring Polymerase Or Fail Replication: Arenaviruses, Bunyaviruses, Paramyxo, Orthomyxo, Filo, Rhabdo; RNA dependent RNA polymerase (have to bring it)
what type of bug is dracunculus medinensis? where can it be found? what does it do to the body? how do you treat it?
helmith; drinking water; after invading intestine and subcutaneous tissue it crawls out of skin and pokes out - skin inflammation and ulceration; Niridazole
what type of bug is Loa Loa? how is it transmitted? what does it do to the body? how is treated?
helminth; deer, mango, horse flies; swelling in skin (can see worm crawling in conjunctiva!); diethylcarbamazine
what type of bug is Diphyllobothrium latum? how is it transmitted? what does it do to the body? how is treated?
helminth; freshwater fish! (raw); vitamin B12 deficiency; anemia; praziquantel
what type of bug is Clonorchis sinensis? how is it transmitted? what does it do to the body? how is treated?
helminth; undercooked fish; causes inflammation of biliary tract- pigmented gallstones and cholangiosarcoma!; praziquantel
what type of bug is Paragonimus westermani? how is it transmitted? what does it do to the body? how is treated?
helminth; undercooked crab meat; inflammation and secondary bacterial infection of the lung, causing hemoptysis; praziquantel
what parasite should you think of when you hear brain cysts and seizures?
taenia solium (cysticercosis)
what parasite should you think of when you hear bilary tract disease and cholangiosarcoma?
how does hepatitis B induce hepatocyte cell death?
from activating the immune response! CTL mediated destruction!
why do immunosuppressed have less inflammation from hepatitis?
because its virulence comes from inducing immune response- cell mediated cytotoxicity
which viral spots start on the face? trunk? fever first then trunk and chest?
rubella and rubeola; varicella; roseola infantum (HHV 6)
what is the acute histology of hepatitis?
diffuse balloon degeneration (swelling) of hepatocytes, mononuclear infiltrates, councilman bodies (eosinophillic apoptotic hepatocytes)
when do you councilman bodies and what are they?
eosinophillic apoptotic hepatocytes; acute hepatits
which viruses are destroyed in the gut (and thus dont cause disease by ingestion)? which viruses can cause disease by ingestion?
enveloped; nonenveloped (naked)
how are protozoa that cause diarrhea ingested? how do they bind to intestinal epithelia?
as cysts (can resist gastric acid this way); convert to motile trophozoites that bind to surface lecithins
what two pathologies cause chronic damage to the mucociliary defenses of resp system? acute damage?
smoking and CF; intubated patients and aspirated gastric acid
what are the symptoms of a cerebral abscess? how do you know if its from contiguous spread from otitis media (for ex) or hematogenous (septic embolism)?
papilledema and focal neurologic deficits (mass occupying lesion); single vs. multiple;
what is a cerebral abscess? what can rupture lead it?
discrete lesion with central liquefactive necrosis surrounded by fibrosis and swelling; meningitis, ventriculitis, venous sinus thrombus
what is the typical pathogenesis for bacterial meningitis?
adherence to mucosa of nasopharynx- bacteremia to BBB- translocation (using bacterial lysins)- bacteria in subarachnoid space attracts neutrophils and cytokines (diapedesis---> albumin in CSF)-- edema causes headache, photophobia, irritibaility, nausea and vomitting, nuchal rigidity
when is an LP contraindicated in meningitis? how do you confirm this?
space occupying lesions; if papilledema or any focal deficits then do CT
what are the complications of meningitis?
hypoxic injury from scarring can cause seizures from focal neural deficits, cranial nerve palsies, CN VIII loss,hydrocephalus (reabsoprtion blocked), endoarteritis obliterans
what is endoarteritis obliterans? what is the biggest perpetrator of it?
scarring of vasculature; TB basilar meningitis can reach lenticular striate and basal ganglia vessels and cause hemorrhage
what predisposes male infants to UTIs? elderly?
infants with congenital defects, vesicoureteral reflex; enlarged prostate
what are some predisposing factors to UTIs?
obstruction, kidney surgery, catheterization, GU malformation, diabetes (neurogenic bladder causes stasis), pregnancy, cyclophosphamide (prevented with mesna)
what is the mcc of a UTI? what is the greatest risk factor?
ascension of microbes from urethra to bladder; sex
what does a urine positive leukocyte esterase test indicate? what is it?
bacterial UTI; an enzyme of PMNS
what does a urine positive nitrite test indicate? what is the exception?
gram negative bacteria (s. saprophyticus)
why do some microbes spread to places drained by lymph nodes?
so can enter lymphatics and then circulatory system from there
other than invading the vascular system and the lymphatics how else can microbes spread through out the body?
inside cells! leukocyte: herpes, HIV, mycobacteria, leishmania, toxoplasma organisms; RBCs: colorado tick fever virus, plasmodium, babesia
what are some nonspecific signs common to many ToRCHeS infections
hepatosplenomegaly, jaundice, thrombocytopenia, growth retardation
in red rashs infections when is usually the highest period of infectivity?
before the rash appears; rash is immunologic response
with which red rash does the virus cause cytoxic T cell damage of the endothelial cells containing the virus BEFORE the rash starts?
what pathogen causes condylomata acuminata? what pathogen causes condylomata lata? lymphogranuloma venereum- what else can this pathogen cause? granuloma inguinale?
HSV; treponema pallidum; C. trachomatis- rectal strictures; calymmatobacterium granulomatis
what is the Fitz Hugh Curtis syndrome? what kind of adhesions does it result in?
infection of the liver capsule (commonly from PID); violet string adhesions of parietal peritoneum to liver
what is hydrosalpinx?
forms from pyosalpinx (from PID usually) and the pus resorbs leaving fluid distending the tube
what is the chandelier sign and what causes it?
seen in PID- extreme uterine tenderness causes cervical tenderness during pelvic exam
other for ectopic pregnancy and infertility, what else salpingitis a risk factor for?
chronic pelvic pain and adhesions