bacterial pathogens 2

Question 1

where do we find chlamydiae species?

Answer 1

they are especially found in columnar epithelial cells that line mucous membranes

Question 2

what do we treat the chlamydiae subgroup with?

Answer 2

ALL are treated with tetracyclines or macrolides

Question 3

Describe chlamidiae

Answer 3

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

Question 4

which chlamydia effects the respiratory tract?

Answer 4

chlamydia pneumoniae and chlamydia psittaci

Question 5

where might someone contract C. Psittaci?

Answer 5

it is a zoonosis

• spread by inhalation of dried infected droppings and/or secretions

Question 6

how do you diagnose chlamydia psittaci and peumoniae?

Answer 6

diagnosis: serology to detect specific IgG, and PCR

Question 7

what chlamydia is associated with genital infection?

Answer 7

chlamydia trachomatis

Question 8

what serotypes of chlamydia are associated with eyes and which are associated with the genital tract?

Answer 8

eyes= A-C

genitals D-K

Question 9

what is the leading cause of infectious blindness worldwide?

Answer 9

Chlamydia Trachoma

Question 10

how do we treat chlamydia trachoma?

Answer 10

SAFE

S= surgical correciton of trichiasis (ingrown eyelashes)

A= antibiotics (azithromycin)

F= facial cleanliness

E= environmental improvements

Question 11

what type of chlamydia?

Answer 11

C. Psittaci

Question 12

what type of chlamydia?

Answer 12

C. Trachoma

Question 13

what type of chlamydia ?

Answer 13

C. Pneumonia

Question 14

what type of clamydia?

Answer 14

C. Trachoma - spread via birth canal

Question 15

what causes Rocky mountain spotted fever?

Answer 15

Rickettsia Rickettsii - in NA, CA, and SA

Question 16

Describe the clinial presentation of Q fever

Answer 16

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

Question 17

What infection do people get from livestock post-birth, that may lead to culture negative endocarditis - presents acutely though with flu-like illness/pneumonia?

Answer 17

coxiella burnetii

Question 18

what is the treatment for coxiella burnetti?

Answer 18

acute = doxycycline

chronic = combination therapy (doxycycline + rifampicin) for a prolonged period

Question 19

Describe the clinical presentation of diphtheriae

Answer 19

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”

Question 20

where do we find listeria monocytogenes?

Answer 20

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

Question 21

describe the clinial features of perinatal listeriosis

Answer 21

• “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

Question 22

how might listeria present in immunocompromised host ?

Answer 22

• bloodstream infeciton
• pneumonia
• meningoecephalitis
• brain absess
• endocaridtis
  *

Question 23

what is the treatment for listeria?

Answer 23

high dose amoxicillin with an gentamicin (for synergy)

resistant to cephalosporins

Question 24

how do patients contract brucella?

Answer 24

zoonosis -

from contact with animal hosts (goats, cattle, pigs, dogs/foxes)

*not very common in Ireland

Question 25

what is the clinical manifestation of acute brucellosis?

Answer 25

incubation 2-4 weeks

fever

influenza like illness

dry cough

lyphadenopathy

depression

osteoarticular infection

GU infection

Question 26

what is the clinical manifestation of chronic brucellosis?

Answer 26

in untreated or inadequately treated patients - recurs over months or years - characterised by sweating episodes, aches/weakness, insomnia