Chlamydia

Question 1

What are Chlamydias?

Answer 1

• obligate intracellular bacteria
• lost their ability to survive outside of eukaryotic cell
• need to invade and replicate
• double membrane - will peptoglycan layer in middle
• truncated lipopolysaccharide
• member of chylamydiales

Question 2

Describe the general characteristics of Chlamydia?

Answer 2

• coccoid
• non-motile
• no flavoproteins or cytochromes - energy generating
• genome = 1.04-1.23 size
• 1000 proteins
• DNA interspecies exchange

Question 3

What does C.pneumoniae infect?

Answer 3

• mammals
• reptiles
• amphibians
• marsupials

Question 4

Which species of Chlamydia infect pigs?

Answer 4

• C.suis
• C.psittaci
• C.abortus
• C.pecorum

Question 5

WHich Chlamydia species are zoonotic?

Answer 5

• C.abortus
• C.suis
• C.psittaci
• C.pneumoniae
• C.felis

Question 6

Describe the developmental cycle of Chlamydia

Answer 6

• Elementary bodies - not dividing and infectious
• attach to eu cell and are ingested
• fuse with phagosome
• then are reticulate bodies - inside a vacuole that provides everything they need
• then RB start to condense into EBs
• form an inclusion body
• cell lysis takes place - releases the EBs
• 72 hour cycle

Question 7

What is an aberrant body?

Answer 7

• persistent infection
• no cell lysis

Question 8

How to ABs form?

Answer 8

• produced under adverse environmental conditions
  
  • too low antibiotic conc
  • host immune response (gamma)
• non-infectious but viable
  
  • have altered transcription of membrane proteins, virulence factors and energy metabolism
• removal of stress allows development
• leads to treatment failure

Question 9

What else happens during infection?

Answer 9

• get actin polymerisation in the cell
• EB sucked into vacuole
• makes an injection needle - interacts with vacuolar membrane
• injects proteins into cell - makes sure vacuole is provided with everything it needs

Question 10

What does Chlamydia trichomatous cause?

Answer 10

• ocular infections
• types A + C
• blindness - developing countries
• infection of the conjuctival ep
• eyelashes scratch the eyeball -> corneal scarring (Trichomatous trichiasis)
• transmitted through discharges (person -person / flies)

Question 11

What is the public health burden of trachomatis?

Answer 11

• 1.9m - visual/ blind
• 40m - with disease
• 190m - at risk
• in endemic areas - 60-90% children infected
• 48 countries have endemic

Question 12

What types of Chlamydia trachomatis causes urogenital infections?

Answer 12

• D and K
• women - uretheritis, cervicitis, PID, ectoptic pregnancy, premature delivery, postpartum fever
• men - urethritis, white discharge out of penis, proctitis, 7-28 days after infection, burning, need to urinate more
• lympogranuloma venereum (LGV) - types L1-L3
• Both - Reiters syndrome

Question 13

What is the public health burden of the urogenital infection?

Answer 13

• <20% lead to infertility
• 70% in under 25s
• 50% of infections resolve themselves in 12 months

Question 14

Treatments for LGV and urogenital/ ocular?

Answer 14

• LGV = tetracycline, 21 days
• ocular/ urogenital = azithromycin or doxycycline - 7 days

Question 15

What is the pathogenesis of EAE?

Answer 15

• detected at 90 days
• targets the trophoblast layer
  
  • causes vasculitis, necrosis and inflammation
• causes abortion:
  
  • ​reduced effiency of the foetal-maternal exchange
  • endocrine dysfunction
  • immune balanced changed

Question 16

Clinical signs of EAE?

Answer 16

• abortion storm 5-10%
• fresh looking lambs - necrotic placenta and dirty pink uterine discharge
• one dead one weak alive lamb can occur
• ewe not affected - future - fertile

Question 17

How do you treat EAE?

Answer 17

• oxytetracycline
• destroy bedding
• clean up aborted material
• do not use lambs fostered on aborted lambs
• cull

Question 18

What are the symptoms of chlamydia felis?

Answer 18

• conjuncitivis, rhinitis, nasal discharge
• common under 1 year
• mucopurulent ocular discharge - secondary infections
• mlti cat households

Question 19

How does chlamydia infect cows?

Answer 19

• bovine encephalomyelitis
  
  • depression
  • salivation
  • high fever
  • diarrhoea
  • reduced coordination
• 2 weeks
• 50% mortality
• tetracycline might help

Question 20

Describe chlamydiosis in koalas?

Answer 20

• massive conservation problem (10-90%)
• C.percorum
• kerato-conjunctivitis
• urogenital and ocular disease
• wet and dirty tail - UTIs and infertility
• ulcerations around tail
• transmission - mother-joey/ sexual
• treatment - antibiotics in early phases/ untreatable in late
• 30 day treatment
• vaccines - partial protection to 3/10 types

Question 21

Which type of Chlamydia infect birds?

Answer 21

• C.psittaci

Question 22

What are the clinical signs of avian Chlamydiosis?

Answer 22

• respitory and digestive disease
• spread through faeces and resp discharge
• activated by stress
• nasal/ocular discharge
• resp distress
• diarrhoea
• Prevent:
  
  • quaratine all incoming birds
  • tetracycline iin food
  • husbandry

Question 23

Is C.pisttaci zoonotic?

Answer 23

• yes
• spread to mammals including humans
• parrot fever
• high fever, chills, non-productive coughing
• difficulty breathing
• chills
• headaches
• death - by pneumonia
• 10 days after
• tetracyclines

Question 24

What does C.pneumonia cause?

Answer 24

• upper and lower resp infections in humans
• infects a wide range of hosts
• 5-10% of infections
• laryngitis, pharyngitis, bronchitis
• spreads from lungs to peripheral organs
• human - human
• 3-4 weeks incubation