Chlamydia and Mycoplasma Flashcards
Where are chalmydias found?
Intracellular
What does Chlamydia use for energy?
Host ATP
What are the two forms of chlamydia?
Infectious (elementary body) and replicative (reticular body)
What is the elementary body like?
Rigid cell wall, low metabolism, extracellular
Where in the body is Chlamydia found?
GI, resp and genital tract
How can contamination by Chlamydia occur?
Infected placentas
Why are Chlamydia carriers so common?
Many mechanisms to evade immune system - inhibits phagolysosome, down-regulates class II antigens, proteolytic cleavage of NFkB
What are clinical signs of ocular Chlamydia?
Conjunctivitis, keratitis, corneal ulceration
What resp signs can Chlamydia cause?
Exudative or purulent bronchiolitis with tracheitis, or pneumonia with areas of consolidation
How big are mycoplasms?
The smallest free-living cells known
What shape do Mycoplasmas take?
Filamentous or spherical
What is the membrane of Mycoplasmas like?
Flexible, with no peptidoglycan
What is gram stain of Mycoplasms?
-ve
How do you grow Mycoplasmas?
Grows slowly, can be cultured on artificial media (tissue culture)
What do Mycoplasma colonies look like?
Nipples
Which toxins do Mycoplasmas produce?
Haemolysin, proteases, nucleases
Which inflammatory cytokines do Mycoplasmas produce?
TNF, IL6, IL1
How do Mycoplasmas attach to the host cell?
Via the anionic surface layer
Which types of Mycoplasma has a specialised surface?
M pneumoniae and gallisepticum
How do some Mycoplasmas increase attachment and predispose to bacteria?
Inhibit or destroy cilia
How can mycoplasmas hide from the immune system?
Decrease phagocytosis by neutrophils or macrophages, decreased respiratory burst allows persistence in Macrophages, antigenic variability, molecular mimicry, induce polyclonal activation of B cells
What do you see at PM in acute Mycoplasma infections?
Inflammation, neutrophil infiltration, fibrin, exudate
What do you see in septicaemic Mycoplasma infection?
Coagulopathy, vascular thrombosis, shock (mediated by cytokines)
What do you see in persistent Mycoplasma infection?
Often asymptomatic
What do you see in localised Mycoplasma infections?
Tissue destruction, mastitis leading to fibrosis, proliferative synovitis, erosive arthritis, pleural thickening
What are the main forms of Mycoplasma infection?
Respiratory, articular, mastitis
How do you diagnose Mycoplasma?
With PCR but hard to culture
What’s the problem with serology for Mycoplasma?
Does not show active infection
What do you treat Mycoplasma with?
Tetracyclines, fluoroquinolones, macrolides
Which class of drugs won’t work for Mycoplasma?
Beta lactams
What can happen after treatment for Mycoplasma?
Post-treatment carrier state
How do you control CBPP or CCPP?
Cull
How do you control Mycoplasma in poultry?
Isolate or cull
How do you control Mycoplasma in pigs?
Isolate or cull
How is the infectious elementary body taken into the cell?
Phagocytosis
What happens to the elementary body in the vacuole?
Restructures to a reticulate body
How does the non-infectious reticulate body replicate?
Binary fission
