Identification of Mastitis Pathogen in Dairy Cow

BENCH 1 This bacterium was isolated from a milk sample taken from a five year old cow with recurrent clinical grade 2A mastitis. The cow has previously been treated with a course of penicillin streptomycin milking cow tubes, but the mastitis recurred 1 week after finishing treatment.  Examine the plates and pictures and based on the cultural and microscopic morphology, identify the pathogen ___Staphylococcus aureus____ Gram staining  Notice the cream-yellow Colonies haemolytic on BA Examine the sensitivity profile provided for this isolate and please select a course of therapy for this cow: Consider extended therapy or combination therapy as a chronic case, e.g. 6 days intramammary therapy or intramammary plus systemic antibiotics. Sensitive to most antibiotics so for a licenced extended therapy product could use Pirsue (pirlimycin) 8 days or Orbenin LA (cloxacillin) 6 days. Monitor somatic cell counts or California Mastitis Test to check if cured or recurring. BENCH 2 This bacterium was isolated from a milk sample from a heifer grazing at pasture. The clinical history is that the heifer has not yet calved, she is off colour and the affected quarter is extremely hard and painful. Examine the cultural and microscopic morphology and identify the pathogen: Note the small haemolytic colonies on BA Gram staining What is the name of the bacteria isolated?_ Trueperella pyogenes (previously Arcanobacterium pyogenes) What is the name of the condition associated with it?____________________  What advice would you give the farmer on prevention of this infection?______________________________________________________  Examine the sensitivity profile provided for this isolate. What treatment would you advise? Strip-out the quarter frequently; NSAIDS, intramammary and systemic antibiotics. A wide choice of antibiotics is available as the isolate presents broad sensitivity. E.g. combination therapy: intramammary and systemic antibiotics as Synulox or Cobactan. Duofast tubes and potentiated sulphonamide injections may also be an option. Some will use long acting macrolide injections (Zactran, Micotil, Draxxin – off licence; tylosin is a short acting) as is not milking and at pasture. BENCH 3 This bacterium was isolated from 6 cows in a herd suffering from repeated high somatic cell counts.    Examine the cultural and microscopic morphology in order to identify the pathogen: and identify the pathogen___Streptococcus uberis Devise a course of treatment for the cows. What is a common environmental risk factor for these bacteria? Note the small alfa haemolytic colonies on BA  Gram staining Examine the sensitivity profile provided for this isolate. Advise on an appropriate course of therapy. Manage as separate group in the parlour, disinfect between cows. Consider extended therapy or combination therapy as a chronic case, e.g. 6 days intramammary therapy or intramammary plus systemic antibiotics (AB). Sensitive to most AB so for a licensed extended therapy product could use Pirsue (Pirlimycin) 8 days, Orbenin LA (Cloxacillin) 6 days, Mamyzin ( injectable AB) or one of licensed combinations, e.g. Synulox or Cobactan. BENCH 4 This bacterium was isolated from the milk of a four year old cow, calved two days, suffering from toxic mastitis. Examine the cultural and microscopic morphology in order to identify the pathogen: and identify the pathogen____Escherichia coli EMB agar; note the specific metallic green sheen Gram staining Examine the sensitivity profile provided for this isolate and describe how you would treat this cow. Also, what areas of farm management should you assess in order to prevent infection with this bacterium spp._________________________________________________ IV fluids, NSAIDS, strip out quarter (use oxytocin), iv AB e.g. potentiated sulphonamide would work fine. Alternatively, sensitive to cephalosporins so could use intramammary Cobactan tubes and i.m. Cobactan injections but 4th generation so use only if needed as used 3rd line in humans.