(08) Mastitis II Flashcards
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repeat
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(Somatic Cells)
- SCC<!--? considered uninfected?</p-->
- US legal limit?
- EU legal limit?
- 200,000 cells/mL
(cut point determines sensitivty of test)
2 < 750,000 cells/ml
< 400,000 cells/ml (US needs to be this for export)
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(California Mastitis Test)
- test for what?
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(On-Farm Culture)
- Aseptically collected milk sample are plated, incubated, and interpreted on-farm
- Fast, inexpensive way to categorize the cause of mastitis into treatment categories:
gram negative, no-growth = ?
gram-positive = ?
- Limitations?
- no treat (with exceptions)
treat
- time, space, personnel, training (does not work well on smaller dairies)
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(Culture Negative Results)
- “no growths” = ?
- cause of false negatives?
- cause of true negatives?
- 25-40% of milk from clinical cases will not grow bacteria
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(Bulk Tank Diagnostics)
(SCC)
1 gives a snapshot of what?
varies greatly depending on what?
(Culture)
- monitoring what?
- screening for what?
- Does it correspond to prevalence of infected cows?
- negative result means what?
- herd infection level
what pathogens are present in the herd
- hygience (lots of bacteria, especially certain types, indicate dirty cow and poor milking hygience)
- contagious pathogens
- NO!
- NOTHING
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- Can mastitis pathogens be diagnosed by clinical symptoms alone?
- NEVER!
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(“Contagious PAthogens”)
- Transmitted when what occurs?
- pathogens?
- when teats exposed to to bacteria that originiated in ifected udders (cow-to-cow, during milking, contaminated equipment or hands)
- staph aureus, strep agalactiae, mycoplasma, other (prototheca?)
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(“Environmental Pathogens”)
- transmitted when what occurs?
- pathogens?
1 teats exposed to bacteria that originate in the environment (bedding, mud, manure - during milking form equip)
- coliforms (E. Coli, Klebsiella, enterobacter)
environmental = streps
environmental staphs/CNS/staph spp
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(Contagious vs. Environmental)
(Infection characterisitcs)
- contagious are usually what?
- environmental usually what?
- G+, mild to moderate clinicals may resolve w/o treatment - likely to revert to subclnical
(set up shop in mammary tissue and persist in balance with immune response)
- G+ maybe clinical or sub (environmental streps sometimes behave more like contagious pathogens)
G- usually opportunistic, short duration, mild to severe clinicals
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(Contagious vs. Environmental)
- However, some “environmental” pathogens have demostrated host adaptation - can be transferred via what?
- In either catergory, some organsisms are difficult to treat whil e others are easy
- via infected milk (E. Coli and Kleibsiella, Strep Uberis)
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(G- vs G+)
(G -)
- illict what type of immune response?
2 rate of spontaneous cure?
(G +)
- immune rsponse?
- rate of spontaneous cure?
- rapid, robust host immune response(why many coliform peracute)
- high (up to 70%)
(lower for Kleibsiella though, and host adapted E Coli)
- less robust
- low rate (usually require intrammary antibiotic therapy with variable success)
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(Common Gram +)
(Staph Aureus)
- catalase? coagulase?
- G+ cocci
3 major contagious mastits pathogen, but variable prevalence here-to-herd (5-50%)
- cure rates?
what two reasons?
- chornic or acute?
- Selecitve treatment based on cow factors, herd control by testing and segregating or culling
- +, +
4 VERY LOW (< 30%)
not obligate (but forms micro-abcesses that IMM Abx can’t get to) AND some penicillin resistance
- typically chronic with acute flare-ups, waxing and waning SCC
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(Common Gram Positives)
(Streptococcus Agalactiae)
- catalase?
- gram + cocci
3 use what to diff from environmental streps?
- contagious, obligate udder pathogen
- How easily cured by IMM Abx?
- prevalence has declined greatly over the years due to what?
- typically chornic, subclinical with 10-15% milk loss
- herd approch to treatment and control is required (clinical case = tip of the iceberg)
- neg
- CAMP test
- easily - no penicillin resistance. stays in lower gland and ducts with minimal interstitial tissue involvement
- dry cow therapy
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(common Gram+)
(Coag- staphs)
- Over 50 species, found on teat skin, nasal tissue,milkers hands, etc. (commensal, opportunistic)
- what to distinguish from Staph Aureus?
- Subclinical mas))s, low SCC (<200,000 cells/ml), clinical cases are typically mild
- Minor pathogen – only 5-10% of clinicals
- spontaneous cure rate?
- control?
- coag test (most non-aureus staphs are coag -)
- high (economic benefit of treatment questionable, short duration therapy only for clinicals)
- teat dipping and dry treatment
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(common Gram+)
(Environmental Streps)
- catalse?
- gram + cocci
- CAMP - why is this useful?
- MAjor pathogens - what % of clinicals?
- CAuse high SCC, persistent infections, bac shed in milk
- Sources?
7 Control - environmental management, hygiene to reduce teat exposure
- Treatment?
- neg
- most are neg - diff from Strep ag
(S. Uberis is esculin positive, some are CAMP positive)
- 20-25% (2/3 of sub become chronic)
- shed in feces, bedding (straw), dry period
- IMM Abx (longer duration tx may be indicated)
(failure to treat –> chronic)
(chronic subclinicals have poor tx success rates)
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(common Gram+)
(Environmental Streps)
- “Non-ag Streps” typically lumped together - Strep Uberis, Strep dysgalactiae, etc…
but what?
- Strep uberis may be more significant, more likely to act like a contagious pathogen, and more difficult to treat
(extended duration therapy indicated)
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(Common Gram-negatives)
(E Coli)
- Most common coliform - it’s everywhere
- May be mild to sever depending on infective dose and host immune response
- Treatment?
- IMM not indicated in most cases (check SCC history), systemic and supportive therapy may be needed for severe cases
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(Common Gram-negatives)
(Klebsiella spp.)
- how common?
- severitiy?
- Bacteria invade deeply into udder )ssue, destroy secretory cells, may become persistent and subclinical
(Severely affected cows never return to normal milk production level)
- Sources: feces, bedding (wood byproducts), dirty udders, infected milk
- Control: ID subclinicals, segregate chronics, good milking, hygiene, consider bedding type, vaccinate
- Treatment?
- 2nd most common GN pathogen (K. oxytoca and K. pneumoniae)
- 1/3 mild, 1/3 mod, 1/3 severe (GN endotoxin)
- no labeled treatment, treat grade 1-2 based on previous history or treat all
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(Common Gram-Negatives)
- how control coliform mastitis?
- What vaccine WORKS?
- reduce exposure to pathogens in environment
- J-5 core antigen vaccine
(reduces clinical cases 50-80%)
(should use 3 doses: 2 late gestation/pre-fresh, and 1 post-fresh)
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(“other pathogens”)
(Mycoplasma)
- bacteria with no what?
- what needed to isolate?
- most common in milk samples?
- contagious - transmitted how?
- classic case?
- treatment?
- ID and segregate, cull ASAP (shed in very high numbers), close management of hospital pen/parlor to minimize transmission
- Bulk tank and/or string samples to monitor
1 cell wall (so no target for ABx)
- special media and icubation
- M. Bovis
(This and other spp. isolated from various body sites in both sick and well caUle)
- air, blood, milk (purchased)
5 multiple quarters affected, decreased milk, cow not sick, normal (subclincal) to abnormal (clinical) milk, increased SCC
6 none, once infected always affected
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(“Other” Pathogens)
(Prototheca)
- colorless, micro-algae (P. Zopfii)
- ubiquitous in environment - esp where?
- spread - contagious or environmental?
- infections usually sub or clin?
- treatment?
- suspect for non-responsive cases
- prevalence 4-40%, usually under 10
- If found in BT culture, consider speciation?
- wet areas
- clincial (mild-mod)
(chronic, high SCC, decreased milk)
- non - ID, segregate, cull
- there is no answer to this
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(Yeast)
- Rare - almost always due to what?
- responsive to Abx?
1 iatrogenic due to dirty IMM infusion technique
- no (some cure spontaneously)
(evalulate SCC to determie when to cull)
