| Line 1: |
Line 1: |
| − | <big><center>[[Infectious agents and parasites|'''BACK TO INFECTIOUS AGENTS AND PARASITES''']]</center></big>
| + | #REDIRECT[[:Category:Corynebacterium species]] |
| − | <big><center>[[Bacteria|'''BACK TO BACTERIA''']]</center></big>
| |
| − | | |
| − | | |
| − | *''C. pyogenes'' in [[Joints - inflammatory#In Sheep|arthritis]] of sheep post-dipping joint infection and [[Joints - inflammatory#In Pigs|arthritis in pigs]] and [[Joints - inflammatory#In Cattle|arthritis in cattle]]
| |
| − | | |
| − | *''Corynebacterium pseudotuberculosis'' may cause [[Muscles - inflammatory#Abscesses|myositis]]
| |
| − | *''Corynebacterium pseudotuberculosis'' in [[Bacterial skin infections#Deep pyoderma|deep pyoderma]]
| |
| − | | |
| − | ===Overview===
| |
| − | | |
| − | *Common inhabitants of skin and mucous membranes of animals
| |
| − | *Opportunistic infections
| |
| − | *Cause pyogenic infections
| |
| − | *Most species host specific
| |
| − | | |
| − | | |
| − | ===Characteristics===
| |
| − | | |
| − | *Small, tough, Gram positive rods
| |
| − | *Pleomorphic
| |
| − | *Cluster together to resemble Chinese characters - coryneform morphology
| |
| − | *Known as diphtheroids
| |
| − | *Catalase positive, oxidase negative
| |
| − | *Facultative anaerobes
| |
| − | *Require enriched media for growth
| |
| − | *Non-motile
| |
| − | | |
| − | | |
| − | ===Pathogenesis and pathogenicity===
| |
| − | | |
| − | *Pyogenic causing suppurative infections except for ''C. bovis''
| |
| − | *''C. bovis'' causes mild neutrophil response in teat canal of healthy dairy cows and may protect from more pathogenic bacteria
| |
| − | *''C. pseudotuberculosis'':
| |
| − | **Facultative intracellular pathogen inside macrophages
| |
| − | **Cell wall lipid
| |
| − | **Produces a phospholipase toxin which hydolyses sphingomyelin in mammalian cell membranes
| |
| − | **Phospholipase may enhance survival and multiplication in host in early stages
| |
| − | *''C. renale''
| |
| − | **Urinary tract pathogens
| |
| − | **Produce urease and hydrolyse urea
| |
| − | **Possess fimbriae for attachment to urogenital mucosa
| |
| − | **Infection when immunity reduced or following tissue damage during parturition
| |
| − | | |
| − | | |
| − | ===Clinical infections===
| |
| − | | |
| − | *Infection follows tissue trauma
| |
| − | *''C. pseudotuberculosis'' casues caseous lymphadenitis in sheep
| |
| − | *Carried on skin of sheep
| |
| − | | |
| − | *Infection through shearing wounds
| |
| − | | |
| − | *Ulcerative lymphangitis in horses
| |
| − | | |
| − | | |
| − | ===Diagnosis===
| |
| − | | |
| − | *Samples include pus, exudate, affected tissues and urine
| |
| − | *Presence of coryneform organisms in smears
| |
| − | *Culture on blood agar, selective blood agar and MacConkey agar
| |
| − | *Do not grow on MacConkey
| |
| − | *Colony characteristics:
| |
| − | **''C. bovis'': lipophilic bacterium; small, white, dry, non-haemolytic colonies on plates inoculated with bovine milk
| |
| − | **''C. kutscheri'': white colonies; occasionally haemolytic
| |
| − | **''C. pseudotuberculosis'': small, white coloniess surrounded by narrow zone of complete haemolysis; colonies become dry and cream-coloured
| |
| − | **''C. renale'': small, non-haemolytic colonies after 24 hours; pigment produced after 48 hours
| |
| − | *Biochemical reactions:
| |
| − | **Certain strains of ''C. pseudotuberculosis'' reduce nitrates
| |
| − | **All pathogenic strains except ''C. bovis'' produce urease
| |
| − | *Enhancement of haemolysis produced by ''C. pseudotuberculosis'' when inoculated across a streak of ''Rhodococcus equi''
| |