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| Question | Answer |
| What is the microscopic appearance of corynebacterium? | pleomorphic- mostly rods/cocci forming palisades. Non-motile Gramm + |
| What is the incubation/ plating method? | Mesophiles with 2 day incubation,facultative anaerobes. Plating on blood agar-enriched |
| What is important component of their cell wall? | high concentrations of lipids. Meso-diaminopimelic acid. Arabinogalactan. Mycolic acids. |
| Results of catalase and oxidase test? | Cat + Ox - |
| What is the urease test and what are its results? | Tests the ability of the bacterium to secrete urease enzyme, which hydrolyses urea to ammonia and carbon dioxide. Ammonia released causes mucosal inflammation. All corynebacterium are + except C. Bovis. |
| Is it possible to treat Corynebacterium with antibiotics (β lactams)? | Yes but only in early infection Not in sheeps! |
| Describe colony of corynebacterium: | Small C. renale= yellow C. pilosum= yellow C. cystitidis= white C. Pseudotuberculosis= white with β-hemolysis after 48-72h incubation. |
| Are corynebacteria usually commensal? | Yes in mucous membranes and can cause pyogenic infections |
| What are usual samples used for testing? | tissue exudate pus mid-stream urine |
| What tests do we usually do? | PCR, ELISA CAMP for C. Pseudotuberculosis and Rhodococcus Equi |
| What are the 2 biotypes of C. Pseudotuberculosis? | 1) nitrate reducing 2) non-nitrate reducing |
| Which corynebacterium has affinity for lymphatic system? | C. Pseudotuberculosis |
| Which animals are affected by the non-nitrate reducing biotype? How? | Sheep and goat. It causes lymphadenitis- abcess formation in lymph nodes or internal organs. |
| Which animals are affected by the nitrate reducing biotype? How does the infection occur? | Cows and horses. The infection occurs by skin wounds, insects or by contact. |
| The non-nitrate biotype is spread by: Is it treatable? | pus, nasal and oral secretions. It is not treatable |
| Ulcerative lymphangitis usually affects (animals:)_____and one major characteristic is_______ | It affects cows and horses. Characteristic is chronic abscesses with greenish pus and blood tinged. |
| Which strain of corynebacterium affects the lower urinary tract of cattle? | C. Renale |
| What is the disease that when it's too serious the kidney must be removed and the patient will need dialysis? Which bacteria cause this disease? | Pyelonephritis- inflammation of kidney tissue- calyces and renal pelvis. It is caused by C. Renale. |
| Unvaccinated individuals and children are more likely to be ill after infection by___?___ | C. Diphtheria |
| How many subspecies does C. Renale have? | 3 C. Renale C. Pilosum C. Cystitidis |
| Effects of C. Renale in different species: | - cystitis & pyelonephritis in BO - ulcerative balanoposthitis in OV+CAP (inflammation of glans penis) |
| What toxin by which strain causes cell death? | DT toxin by C. Diphtheria |
| Where can we see hemolysis? | C. pseudotuberculosis |
| Where can we find urease? | All pathogenic strains except C. bovis |
| How does DT toxin work? | AB toxin= 2 components: one for activation, one for binding. It is encoded by a bacteriophage and secreted when Fe levels are low. *It enters the cytoplasm of cell and inhibits protein synthesis- DNA/RNA decreased- energy metabolism also affected=> CELL DEATH If the toxins reaches the organs via bloodstream it can cause paralysis and congestive heart failure. |
| Which strain produces exotoxins and phospholipase D? | C. Pseudotuberculosis |
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