1. O bligate intracellular bacteria

2. Obligate intracellular bacteria of veterinary importance genus Chlamydia Coxiella Anaplasma Lawsonia developmental sporesarthropod zoonosiscell target forms transmission + - -+ epithelium & M  - + ++ epithelium & M  - - +- M  & PMNL - - -+ epithelium

3. 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

4. Chlamydiae as animal pathogens Chlamydia spp. Chl. trachomatishuman ocular and urogenital Chl. muridarummouse respiratory infection Chl. suisporcine pneumonia, enteritis, conjunctivitis Chlamydophila spp. Cp. pneumoniaehuman, horse, koala Cp. pecorum ruminants, pigs, koalas - multisystem Cp. caviaeguinea pig conjunctivitis/pneumonitis Cp. psittaciavian- multiple serovars Cp. abortusruminant abortion Cp. feliscat conjunctivitis, rhinitis Potential ZOONOSES

5. Chlamydia/Chlamydophila developmental phases Elementary Body (EB): 300-500nm infective stage spore-like resistant to environmental stresses Reticulate Body (RB): ~2000nm non-infective replicative stage binary fission

6.  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

7. ingestion/ inhalation  localisation to tonsils/lymph nodes  dissemination  latent, persistent or intermittent infection  placentitis  foetal infection  abortion stillbirth weak lambs subclinically infected lambs Chlamydophila abortus

8. Enzootic Abortion of Ewes (EAE) / Ovine Enzootic Abortion (OEA) Antibiotic treatment – tetracyclines Closed flocks / OEA-free accreditation Vaccines: Mediavac, Enzovax, Cevac Chlamydophila ZOONOSIS: respiratory & abortion 1st exposure  ~30% abort  2nd exposure  ~5% abort

9. 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. psittaci Psittacosis, Ornithosis widespread in birds adult birds - usu. asymptomatic, persistent ZOONOSIS

10. Feline Chlamydiosis - Cp. felis mucopurulent conjunctivitis & rhinitis highly infectious ZOONOSIS

11. Zoonotic Chlamydiosis Fever Chills Headache Muscle aches Dry cough malaise pneumonia endocarditis/meningitis Abortion Avian source: 1620 cases Feline source: rare Ovine source:rare

12. 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

13. 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

14. Anaplasma phagocytophilum - morulae

15. 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

16. (previously Bacillus piliformis) intracellular; Gram-negative; spore-forming; obligate anaerobe phylogenetically Clostridium mice; foals, cats, dogs50-100% fatal colonises enterocytes  enteritis relocalises to LN  lymphadenitis relocalises to liver  necrosis Tyzzer's Disease - Clostridium piliforme