Post on 18-Dec-2015
Obligate intracellular bacteria of veterinary importance
genus
Chlamydia
Coxiella
Anaplasma
Lawsonia
developmental spores arthropod zoonosis cell target forms transmission
+ - - + epithelium & M
- + + + epithelium & M
- - + - M & PMNL
- - - + epithelium
Detection of intracellular bacteria
Microscopy:non-specific staining immunohistochemistry
(antigen detection)
Immune responses: antibody or CMI
Genomic detection:PCR
Culture: co-culture with eukaryotic cells
Chlamydiae as animal pathogens
Chlamydia spp.Chl. trachomatis human ocular and urogenital Chl. muridarum mouse respiratory infectionChl. suis porcine pneumonia, enteritis,
conjunctivitis
Chlamydophila spp.Cp. pneumoniae human, horse, koalaCp. pecorum ruminants, pigs, koalas - multisystemCp. caviae guinea pig conjunctivitis/pneumonitisCp. psittaci avian - multiple serovarsCp. abortus ruminant abortion Cp. felis cat conjunctivitis, rhinitis
Potential ZOONOSES
Chlamydia/Chlamydophiladevelopmental phases
Elementary Body (EB):300-500nm infective stagespore-likeresistant to environmental stresses
Reticulate Body (RB):~2000nmnon-infective replicative stagebinary fission
host cell lysis
Elementary Body (EB)
Chlamydia/Chlamydophila infection
adherence to cell membrane
entry by endocytosis
prevention of phagosome-lysosome fusion
transformation of EB to Reticulate Body (RB)
division - formation of "inclusion"
differentiation to EB
ingestion/ inhalation
localisation to tonsils/lymph nodes
dissemination
latent, persistent or intermittent infection
placentitis
foetal infection
abortionstillbirth
weak lambssubclinically infected lambs
Chlamydophila abortus
Chlamydophila abortus
Enzootic Abortion of Ewes (EAE) /
Ovine Enzootic Abortion (OEA)
Antibiotic treatment – tetracyclines Closed flocks / OEA-free accreditationVaccines: Mediavac,
Enzovax, Cevac Chlamydophila
ZOONOSIS: respiratory & abortion
1st exposure ~30% abort 2nd exposure ~5% abort
young/ stressed
- acute, generalised disease
- multisystemic inflammation
(air sacs, lung, intestine, pericardium)
- discharges, depression, inappetance, diarrhoea
- dissemination to spleen, liver, kidneys
- up to 90% mortality
convalescent carriers
Avian Chlamydiosis - Cp. psittaciPsittacosis, Ornithosiswidespread in birds
adult birds
- usu. asymptomatic, persistent
ZOONOSIS
Zoonotic ChlamydiosisFever Chills Headache Muscle aches Dry coughmalaisepneumoniaendocarditis/meningitisAbortion
Avian source: 1620 casesFeline source: rareOvine source: rare
A. phagocytophilum Tick-Borne Fever neutrophil
E. canis Canine Ehrlichiosis monocyte
E. chaffeensis Canine & Human Ehrlichiosis neutrophil
E. risticii Potomac Fever enterocyte
Anaplasmoses / Ehrlichioses
Anaplasma spp. & Ehrlichia spp.
ARTHROPOD-BORNE
GEOGRAPHICALLY RESTRICTED
Anaplasma phagocytophilum
Pathogenesis of Tick-borne fever - TBF
tick haemolymph
inoculation by tick bite
infection of PMN
tick pyaemia (S. aureus)louping ill
neutropaenia
fever, abortion
2° infections
asymptomatic in ruminants
Coxiella burnetti - Q Fever
?? occ. abortion
excreted in urine, faeces, milk, placenta
inhalation by human
infects respiratory epithelium, endothelium & phagocytes
influenza-like syndrome pneumonia endocarditis
ZOONOSIS