bacterial pathogens 2 Flashcards
where do we find chlamydiae species?
they are especially found in columnar epithelial cells that line mucous membranes
what do we treat the chlamydiae subgroup with?
ALL are treated with tetracyclines or macrolides
Describe chlamidiae
gram negative intracellular pathogen - needs host as energy source
exists in 2 forms
1) elementary body - the infectious particle, tough membrane, taken into host by phagocytosis
2) reticulate body - larger replicative form - formed by reorganisation of the EB once it has entered the host cell
which chlamydia effects the respiratory tract?
chlamydia pneumoniae and chlamydia psittaci
where might someone contract C. Psittaci?
it is a zoonosis
- spread by inhalation of dried infected droppings and/or secretions
how do you diagnose chlamydia psittaci and peumoniae?
diagnosis: serology to detect specific IgG, and PCR
what chlamydia is associated with genital infection?
chlamydia trachomatis
what serotypes of chlamydia are associated with eyes and which are associated with the genital tract?
eyes= A-C
genitals D-K
what is the leading cause of infectious blindness worldwide?
Chlamydia Trachoma
how do we treat chlamydia trachoma?
SAFE
S= surgical correciton of trichiasis (ingrown eyelashes)
A= antibiotics (azithromycin)
F= facial cleanliness
E= environmental improvements
what type of chlamydia?
C. Psittaci
what type of chlamydia?
C. Trachoma
what type of chlamydia ?
C. Pneumonia
what type of clamydia?
C. Trachoma - spread via birth canal
what causes Rocky mountain spotted fever?
Rickettsia Rickettsii - in NA, CA, and SA
Describe the clinial presentation of Q fever
it is a worldwide reservoir - cattle, sheep, goats, cats etc.
highly infectious can form spores which can survive for prolonged periods outside of host
usually acquired from occupational exposure to infected animals -
inhalation of contaminated aerosols arising from the placenta or parturient fluids of infected livestock
patients may present with acute infection (flu-like illness), pneumonia, hepatitis
They may also present with chronic infection b/c they did not come to clinic with acute infection - the chronic result is culture negative endocarditis
What infection do people get from livestock post-birth, that may lead to culture negative endocarditis - presents acutely though with flu-like illness/pneumonia?
coxiella burnetii
what is the treatment for coxiella burnetti?
acute = doxycycline
chronic = combination therapy (doxycycline + rifampicin) for a prolonged period
Describe the clinical presentation of diphtheriae
incubates 2-6 days
sterile blood cultures (would culture necessary)
produces toxin at site of infection which enters bloodstream and has systemic effects - antibiotics won’t be active against formed toxin
some people carry it asymptomatically
enters via skin break after contact with infected person - forms a “papule”
where do we find listeria monocytogenes?
it is isolated from soil/water/vegetation/faeces of infected mammals and birds
transmitted by animal contact, consumption of infected food or verticla transmission from mother to child
describe the clinial features of perinatal listeriosis
- “influenza- like illness” =- fever myalgia backache headaches arthralgias
- could be asymptomatic
- perinatal infection may result in miscarriage or intrauterine death, premature labour and infected infant
how might listeria present in immunocompromised host ?
- bloodstream infeciton
- pneumonia
- meningoecephalitis
- brain absess
- endocaridtis
*
what is the treatment for listeria?
high dose amoxicillin with an gentamicin (for synergy)
resistant to cephalosporins
how do patients contract brucella?
zoonosis -
from contact with animal hosts (goats, cattle, pigs, dogs/foxes)
*not very common in Ireland
what is the clinical manifestation of acute brucellosis?
incubation 2-4 weeks
fever
influenza like illness
dry cough
lyphadenopathy
depression
osteoarticular infection
GU infection
what is the clinical manifestation of chronic brucellosis?
in untreated or inadequately treated patients - recurs over months or years - characterised by sweating episodes, aches/weakness, insomnia
