anirugh singh (2/20./18) Flashcards
morphology of Corynebacterium diphteriae
gram+
aerobic
pleomorphic club-shpared rods
catalase reaction with Corynebacterium diphteriae
possitive
what does Corynebacterium diphteriae grow on
on rich media enrich with blood or animal material
where does Corynebacterium live
live oropharynx as a pathogen
what does Corynebacterium diphteriae produce
diphtheria toxin encoded on a lysogenic bacteriophage
what are non-commensal Corynebacterium called
diphteriae
where do Corynebacterium diphteriae live
pharynx, nasopharyn, distal urethra, and skin
what is diphteria
disease caused by the local and systemic effects of siphtheria toxin
local disease of Diphtheria
pharyngitis or tonsillitis, with plaque -like psuedomembrane in throat and trachea
Diphtheria toxin in blood can affect
multiple organs, heart=produces myocarditis
what type of toxin is Diphtheria toxin
A-B endo toxin
how does Diphtheria toxin work
B binds to cell
internalized by endocyctic vacuole
low pH of vacuole caused toxin to unfold
A subunit goes to cytoplasm A subunit (ADP-ribosylate elongation factor-2 (EF-2)) leads to inhibition of protein synth
how is Corynebacterium diphteriae spread
droplet, direct contact with cuatneous infection
lesser extent by fomites
carriers through pharyngeal or nasal to harbor the organism for a long time
commonality of Corynebacterium diphteriae disease
rare where immunication is practiced (10 cases per year
diagnosis of Corynebacterium diphteriae
clinical
cutulure on selective medium containgin potassium tellurite (tinsdale medium)
how body tried to fight the Diphtheria toxin
Diphtheria toxin is antigenic, stimulating production of neutralizing antitoxin antibodies during natural infection
what is formalin
inactivated toxin, remaining natigenic to stimulate neutralizing antibodies
treating diphtheria
diphtheria antitoxin
penicillins, cephalosporins, erythrocymcin, tetratcyclin
how is diphtheria antitoxin made
antiserum produced in horses
immunization of diphtheria
with diphtheria toxoid by stimulating production of neutralzing antibodies
how immunity gained for diphtheria
first year of life with 3-4 shots
booster every 10 years to maintian immunity
morphology of Listeria monocytogenes
aerobic, gram + rod
features resembling both corynebacteria and streptococci
how to distinguish Listeria monocytogenes from streptococci
Listeria monocytogenes
is catalase positive
growing Listeria monocytogenes
rich media
can grow at low temp (0degrees C)
how distinguish Listeria monocytogenes from corynebacteria
tumbling motility in fluid media at low temp (below 30 C)
what Listeria is pathogenic to human
Listeria monocytogenes
stereotypes of Listeria
13 serotypes (most common 1/2a. 1/2b. 4b)
how Listeria monocytogenes is a pathogen
intracellulat
when does Listeriosis show it self
until dissemination
foodborne outbreaks of Listeriosis leads to
GI primary infection leading to nausea, ab pain, diarrhea, and fever
Disseminated infection in adults of Listeriosis leads to
fever, malaise, occasional bacteremia
can cause encephalitis and meningitis
a fetus getting Listeria monocytogenes leads to
still burth or fulminant neonatal sepsis
major virulence factors of L. monocytogenes
Internalin and Lysteriolylis O
what does L. monocytogenes infect
phatgocytes by endocytosis to replicate there and eventually infects neighboring cells by actin polymerization
how does L. monocytogenes attach to host cell
Internalins (InIA, and InIB)
what lyses the endocytic vacuole for L. monocytogenes
Listeriolysin O (LLO)
where is L. monocytogenes foudn
ubiquitous in nature: soil, water, GI of animal
Food born: deli meat, dairy, n-cooked food at low temp
why is it hard to eliminate L. monocytogenes
forms biofilms
who is most susceptible for L. monocytogenes
infacts under 1 month and the elder over 60
diagnosis of L. monocytogenes
Blood and CSF culture show beta-hemolytic gram positive rods
immunology to L. monocytogenes
innate( neutrophil kills bacterial) and adaptive immune(T cell mediated for resolution of infection and long term protetion response
preventing L. monocytogenes
No vaccine
avoid unpasteurized dairy and cooking food
don’t be immunocompromised
treating L. monocytogenes
Ampicillin and trimethoprim/sulfamethoxaole
considered the treatment of
choice for fulminant cases and in patients with severe compromise of T-cell function for L. Monocytogenes
ampicillin with gentamicin
Morphology of Bacillus anthrasis
gram+, aerobic, spore forming long chain rods
non-motile
growing bacillus anthrasis
on rich media
spores of Bacillus anthrasis
extremely hardy and live for a long wall
where does Bacillus anthrasis live
soil, zonnotic
what does Bacillus anthrasis
Antrax A
what is human anthrax
lly an ulcerative sore on an exposed part of
the body, which usually resolves without complications
how to get Bacillus anthrasis spore to germinate
rich encironment of human tissue
role of capsule in Bacillus anthrasis
antiphagocytic effect of glutamic acid capsule for virulence
how does the anthrax toxin cause edema at site of infection
Adenylate cyclase activity
what happens if anthrax spores are inhales
fulminant pneumonia leading to respiratory failure and death
who gets anthrax
primariliy herbivors (get B anthraxis from pastures) Humans contant is from contacting these animals
Diagnosis of Bacillus anthrasis
Culture of skin lesions, sputum, blood, and CSF
smears with large gram+ rods usually are anthrax
hemolysis and motility exclude B anthracis
sputum and blood culture are positive in pneumonia
how do we fight B anthracis
unknown: antibody directed against the toxin complex
capsular glutamic acid is immunogneic but antibody doesnt fight it
treating Bacillus anthrasis
ciprofloxacin and doxycyclin
eradication of animal anthrax
live and inactivated vaccines
morphology of mycoplama and ureaplasma
smallest free living micro organisms(.2-.3 micrometers)
with no cell wall
plastic and pleomorphic as:
coccoid bodies, filaments, and bottle-shaped forms
Mycoplasma pneumoniae is an aerobe, but others are facultative anaerobix
how Mycoplasma and Ureaplasma cells bind
a single trilaminar membrane, with host derived exogenous sterols
growth of Mycoplasma and Ureaplasma
enriched liquid culture medium and on special mycoplasma agar to produce minute colonies that look like fried eggs
what disease does Mycoplasma pneumoniae cause
walking pneumonia
where does Mycoplasma pneumoniae infect to cause walking pneumonia
trachea, bronchi, bronchioles, and peribronial tissue
also alveoli and alveolar walls
walking pneumoniae symptoms
nonproductive cough, fever, and headache
radiographic scatter pneumonia
who gets walking pneumoniae real bad
immune deficiences
sickle cell
downs
what is common with Mycoplasma pneumoniae
pharyngitis and ototis
roll of CARDS toxin in wlaking pneumoniae
interferes with ciliary action and causes nuclear vacuolization and fragmentation of tracheal epithelial cells leading to inflammation and desquamation the mucosa
(ADP-ribosylating)
commonality of Mycoplasma pneumoniae pneumonia
10%
who is Mycoplasma pneumoniae infection spread
droplet with a small dose (100 orgs)
who gets Mycoplasma pneumoniae
teenagers
families and closed communites
throughout the year
immune response to Mycoplasma pneumoniae
T and B cell - mediate to help stop reinfection
when complement-fixing serum antibodies titers reach their peak
2-4 weeks after infection and disappear over 6-12 months
what does the • Nonspecific immune responses to the glycolipids of the
outer membrane of the organism from mycoplasma pneumoniae cause
cold agglutinins, IgM, hemolysis and
Raynaud phenomena
diagnosis of mycoplasma pneumoniae
culture and staiing doesnt work: slow growth and n cell wall
serologic test using complement fixation( • Single high CF or cold hemagglutinins IgM-specific antibody titer
supports diagnosis, however, cold hemagglutinins are nonspecific)
PCR for rapid and specific diagnosis
when doing culture and staining, if there is none, what do you have
viral or mycoplasma etioloty
treating mycoplasma pneumoniae
macrolides
doxycyclin
fluoroquinolones
no vaccine
what other mycoplama and ureaplasma can cause STD’s
Mycoplasma genitaliumand two species of Ureaplasma are leading
candidates to join Neisseria gonorrhoeae and Chlamydia trachomatis
as causes of sexually transmitted` genital infection
morphology of Mycobacterium tuberculosis
slim, poor staining bacilli whave acid fastness (red carbol fuchsin through the decolorization setp obliagte aerobe no spores nonmotile
where do Mycobacterium tuberculosis live
animal host (pathogen) environment (no pathogen)
why are Mycobacteria unique
lipid rich cell wall
how does TB manifest
systemic , but only shown in the most exposed people
shows after a long period of asymptomatic
symptoms of active TB
chronic pneumonia, fever, cough, bloody sputum, and weight loss
What does TB do once it leaves the Lung
central nervous gets fucked up
how does one get TB
inhalation of droplet nuclei carying the organism
1 cough can generate 3000 infected droplet nuclei, and you only need 10 bacilli to initate a pulmonary infection
imunity against TB
High initate immunity
TH1 immunity important
Cytotoxic CD8+ lymphocytes also
diagnosis of TB
acid fast stains
PCR
Tubercullin test
Qauntiferon gold
drugs for TB
first line: isoniazide, ethambutol, rifampin,pyrazinamine
second line: para-aminosalicylic acid, ethionamide, cycloserine, fluorquinolones
BCG vaccine protetive afainst meningeal TB and Efficacy angainst pulmonary TB varies
