other gram negatives Flashcards
what gram negative diplococci is a colonizer of the airway and may cause otitis media ?
moraxella catarrhalis
what are the 2 important species of neisseria and what do they look like ?
meningitidis and gonorrhea
gram negative cocci in pairs (diplococci)
what do the different species of neisseria ferment ?
meningococcus ferments maltose
gonococcus ferments only glucose
what antibiotic is often used for neisseria infection ?
ceftriaxone
3rd generation cepahlosporin
what is the virulence factor associated with the neisseria species ?
IgA protease
how is meningitides transmitted ?
transmitted through respiratory droplets
what is the main virulence factor of neisseria meningitides ?
the outer polysaccharide capsule which prevents phagocytosis
along with the LOS outer membrane which acts as an endotoxin
what does the n meningitides vaccine contain ?
capsular polysacchrides
cause anti capsule antibodies
what is the compliocation associated with neisseria meningitides ?
often associated with meningococcemia
sepsis
DIC
waterhouse fredrichsen syndrome ( low cortisol levels)
if a patient with n meningitis present with a rash what is the most likely diagnosis ?
meningococcemia
what is the prophylaxis of n meningitis ?
rifampin or ciprofloxacin
what autoimmune defeciency disorder is associated with recurrent neisseria meningitis infections ?
problem with the alternative pathway
C5-C9 defeciency
also recurrent infections with encapsulated bacteria
what are the diseases associated with N gonorrhea ?
gonorrhea
PID
septic arthritis
neonatal conjunctivitis
Fitz-Hugh-Curtis Syndrome
why dont you get long term immunity from gonorrhea ?
antigenic variation of pilus protein
why cant there be a vaccination for gonorrhea ?
due to antigenic variation of pilus protein
what does gonorrhea as an STD present as in women vs men ?
men - urethritis
women - cervicitis but not painful
what is the common co infection with gonorrhea ?
chlamydia
what sign is associated with PID ?
dyspareunia ( painful intercourse)
cervical motion tenderness ( chandelier sign)
what is fitx hugh curtis syndrome ?
perihepatitis
inflammatin of glisson capsule
what specific sign is associated with fitz hugh curtis syndrome ?
violin string adhesions
associated with pleuritic pain
what is the most likely diagnosis in a young sexually active patient who presents with swollen warm painful knee ?
septic arthritis
what is the prophylaxis for neonatal conjunctivitis ?
erythromycin opthalmic ointment
what stain is often used for chlamydia ?
giemsa stain and for intracellular bacteria 3amatan
what is the treatment for chlamydia ?
azithromycin doxycycline
what are the two phases of mthe chlamydia life cycle ?
1- elementary body
enters the cell through endocytosis
non active but infectious
2- reticulate body
replicates inside the cell through fission
metabollically active but non infectious
what are the 3 types of chlamydia ?
chlamydia trachomatis
chlamydophila pneumonia
chlamydophila psittaci
what is the presentation of chlamydia in newborns ?
can either cause conjunctivitis or cause pneumonia
what is the presentation of pneumonia caused by chlamydia in newborns ?
classic feature is staccato cough
inspiration between each single cough
often have a history of conjunctivitis
what are the tests for chlamydia ?
NAAT test
what autoimmune diease is associated with chlamydia infection and what is the treatment ?
reactive arthritis : Reiters syndrome
arthritis
conjunctivitis
urethritis
treated with NSAIDS
what happens when chlamydia enters the lymphatics ?
lymphogranulosum venereum
no urethritis is associated
first presents with genital ulcers
then later on painful inguinal lymph nodes
what eye disease can be caused by chlamydia ?
trachoma
enumrate the c trachomatis serotypes and the diseases they cause :
A,B,C : trachoma
D through K : urethritis, PID, neonatal pneumonia and conjunctivitis
L1,L2,L3: lymphogranuloma venereum
what are the oxidase positive coma shaped organisms ?
campylobacter and vibrio
what does the term microaephilic mean ?
mean the organisms require oxygen to live but live better with lower levels of oxygen
this includes vibrio and campylobacter
what is the most common cause of acute diarrhea in children ?
campylobacter
what autoimmune disease does campylobacter often trigger ?
guillian barre
what is the cholera toxin carried by ?
by a bacteriophagea
what is the mechanism of action of the cholera toxin ?
permanently activates Gs and hence increasing the levels of cAMP
rice water diarrhea is specific to which pathogen ?
cholera
what drugs may be associated with a higher risk of cholera infection ?
acid suppression drugs
what are the other two vibrio ( not cholera) and what are their associated features ?
vulnificus - can infect wounds after swimming in fresh water
parahemolyticus
both cause food poisoning , found in oysters
what does the HIb vaccine have ?
type B capsule
conjugated to carrier protein
what are the infections associated with h influenza b ?
epiglottitis - sore throat , difficulity breathing in an unvaccinated child
meningitis
otitis media
pneumonia
sinusitis
what is a classic sign seen in epiglottitis ?
epiglottis will appear cherry red
what type of haemophilus is associated with genital ulcers ?
haemophilus ducreyi
causes painful genital ulcers
forms chancroid
how are chancres in syphillus differentiated from chancres in h ducreyi ?
syphillus chancres are non painful
h ducreyi chancres are painful
what are the features for each of these diseases :
syphillus
h ducreyi
herpes
lymphogranuloma venereum
syphillus: painless chancre
h ducreyi : painful chancre
herpes : multiple vesicle/ulcers
lymphogranuloma venereum : large swollen lymph nodes
what is the cause and presentation of whooping cough ?
bordatella pertussis
URI with severe coughing
post couggh vomiting
can last for weeks
what is the mechanis of pertussis toxin ?
inhibition of Gi proteins
allows over activation of adenylate cyclase
impaired recruitment of neutrophils
where is yersinia enterocolitica found ?
in domesticated animals
often transmitted through pork
what inflammatory response does yersinia enterocolitica cause ?
mesenteric adenitis
which may mimic crohn’s or appendicitis
what bacteria is described to have a safety pin appearance ?
yersinia
