Lactation final exam!!!

Tell me about G variable gram staining?

mix of pink and purple 1. decrease in peptidoglycan thickness during growth (some species)

What does the immune function in the fresh period cause?

negative energy balance parturition

What are some non-antibiotic options?

option 1. watchful waiting 2. dry off affected quarter 3. dry cow off early 4. culling 5. segregate cow and use quarter milker for abnormal milk considerations considerations 1. culling a. cows diagnosed with mycoplasma bovis, staph a. or other incurable organisms b. cows: economically nonviable c. cows= 3+ lactations and have history of chronic mastitis 2. segregate cows a. culling or early dry-off isnt an option b. cows in this pen should be high priority for culling and DNB

Mastitis in man

1. 1 of the main causes of undesired weaning a. up to 33% of women affected 2. milk cultures and antibiotic susceptibility testing are not routinely performed a. usually treated with broad spectrum antibiotics

Ls: what is the relationship with milk yield?

1. 1st lactation: 1 unit SCS-> decrease 200 lb milk (whole lactation( 2. older cows: increase 1 unit SCS-> decrease 4oo lb milk (whole lactation)

immunoglobulins

1. IgM/IgD: secreted by B cells and respond early to infection 2. IgA: present in secretions and mucosa surfaces (1st line of defense) a. predominant in Ig in monogastric colostrum 3. IgE: functions during parasitic infections and allergic reactions 4. IgG: major class of immunoglobulins in blood a. predominant Ig in ruminant colostrum

Tell me about justifiable antibiotic use: what should we ask?

1. Should i involve antibiotic use 2. should only be used when there is reasonable likelihood that bacterial infection is present 3. narrow-spectrum antibiotics that are less critical from human illnesses should be 1st choice 4. use for as short a duration as possible 5. review medical history and cow characteristics before administering antibiotics.

what are some dry cow products?

1. antimicrobial infusions a. Dry, Clow. TOMORROW, quartermaster, spectra DC b. single dose c. most are reasonably effective against Get 2. internal teat sealant a. orbseal, teatseal b. supplement the natural keratin plug forming in late dry period c. can be used without antibiotic IF udder isn't infected d. external teal sealant

What are some innate mammary senses?

1. barriers (teat end) 2. humoral (soluble) factors (lactoferrin, cytokines) 3. cellular factors (neutrophils, macrophages)

What is immunity?

1. branch of science dealing with components of the immune system 2. recognition of self/non-self compounds 3. response to stimuli and molecules strance to the body (PAMP and antigens) 4. Host protection 5. vaccine-vacca (cow)

Swine: coliform mastitis

1. can be multiglandular or uniglandular a. uni: often associated with teat abnormalities or trauma 2. symptoms a. off-feed constipation, fever, swelling of mammary glands b. deny piglets teat access c. consequence: increase preweaning mortality (crushing, poor health)

Tell me about on farm culturing

1. cheap ($3/ sample and incubator 2. fast 3. informed decision-making

Staph aureus: contagious pathogen

1. colonizes teat skin lesions and teat canal a. controllable hard to eliminate but not impossible b. heifers are a reservoir 2. G+ 3. damage the duct system a. reversible during early infection b. pockets of infection, then abscesses and walling off bacteria by scar tissue 4. very chronic, mostly subclinical, although recurring cases can occur 5. detected in 22% of human mastitis cases a. most common species isolated (88% of cases) was staph e. ( lives on skin flora)

Tell me about dry cow therapy

1. curing existing infections a. advantages v. lactating cow therapy b. higher cure rate (especially staph a.) due to higher dose of antibiotic thats retained in the udder longer c. regenerate tissue damaged by mastitis d. lower risk of BT contamination with antibiotic residue 2. preventing new infections

Tell me about gram - gram staining

1. does not retain crystal violet stain 2. thin peptidoglycan layer between inner cell membrane and outer bacterial membrane

How does the mammary gland respond: soluble factors: inflammation

1. eliminates or neutralizes source of injury 2. assists in repairing damaged tissue to normal function 3. initiated by release of mediators from damaged tissue

What is a bi-plate

1. factor media a. G+ growth only 2. macConkey media b. G- growth only

Mycoplasma spp.

1. highly contagious, less common a. outbreaks of clinical mastitis that resists treatment b. associated with swollen joints, respiratory disease c. unresponsive to treatment 2. may damage secretory tissues, productive fibrosis in udder, walled-off abscesses 3. symptoms a. sudden swelling in udder, abnormal milk and multiple quarters b. cows have severe mastitis but appear otherwise healthy.

mycoplasma Spp.

1. highly contagious, less common a. some infections originate in other body sites 2. no cell wall: neither G+ or G- a. resistant to antibiotics that target cell wall b. no nucleus or membrane-bound organelles 3.outbreaks of clinical mastitis that resists treatment a. associated with swollen joints, respiratory diseases b. drop milk production or cease in lactating mycoplasma bovis is most common in dairy cattle a. also mycoplasma alkalescens (respiratory), mycoplasma canadense (joints) and others

What are some prevention steps?

1. hygiene a. stall design b. facility cleanliness c. inorganic bedding (ex: sand) d. high risk times: involution and parturition 2. milking procedures a. ensure proper letdown b. clean techniques c. promotes standing after milking d. milk and infected cows last (contagious) 3. immune health a. decrease health (ex: social stress, heat stress) b. nutritional considerations (vit A and E, and selenium) c. vaccination

Tell me about coliform mastitis

1. infections tend to be acute and clinical, but can be chronic or cubclinical 2. 30-40% of clinical mastitis causes, but overall low prevalence a. most common cause of severe cases 3. high risk times a. early dry period and transition period b. seasonal patterns (high temp, heavy rainfall) 4. symptoms a. severe cases can result in death, most cases= mild-moderate b. high fever (possibly followed by low temp) udder swell, off-feed, dehydration and diarrhea, low production, milk (usually 1 quarter)

Tell me about immediate therapy options

1. injectable antibiotics- prevents bacteria from spreading to bloodstream- high priority- ex: ceftiofur products 2. fluids: prevent dehydration death- very high priority 3. NSAID- relieve pain and decrease inflammation- high priority- ex) flunixin mylamine 4. Intramammary antibiotics- reduce bacteria in gland- low priority (only benefits G+)

What does a mammary gland under attack include?

1. invasion: teat duct 2. infection: gland cistern 3. inflammation: glandular tissue a, considerable increase in SCC mostly due to neutrophil accumulation b. clinical signs may begin to manifest

Structural defense of the teat: tell me about the sphincter muscles and what happens if any trauma occurs

1. keeps the opening closed 2. traumas may compromise the ability the sphincter muscles to close the canal and prolong the exposure of the teat end to mastitis- causing pathogens post milking

Barriers: what are some key components of innate immunity?

1. keratin plug 2. sphincter muscle 3. physical barriers 4. chemical barriers

Structural defense of the teat: Tell me about keratin

1. lines teat duct 2. occludes ducts (physical barrier) 3. antibacterial FA: myristic, palmitoleic, and linoleic (chemical barrier)

Tell me about coliform bacteria

1. lives in soil, digestive tract, and manure 2. G- 3. common mastitis pathogens: escherichia E coli, Klebsiella pneumonia, klebsiella oxytoca, enterobacter aerogenes a. E coli= fecal coliform b. K. pneumoniae= common in saw dust bedding 4. infections tend to be acute and clinical but can be chronic or subclinical a. LPS can result in severe illness or death in some cases b. klebsiella infections are 2X more likely to be culled 5. most commonly isolated bacteria from mastitis cases in sows

Tell me about the specific third line of defense.

1. lymphocytes 2. antibodies 3. memory cells

quad-plate

1. macConkey's media a. G- 2. Quad II: edwards modified media (strep) 3. Bair d Parker media a. Staph 4. Blood media a. grows most bacteria types for confirmation

Gangrenous mastitis

1. mammary glands become necrotic a. patchy blue discoloration and cold to touch 2. caused by some strains of staph aureus a. produce vasoconstriction alpha toxin 3. other pathogen: clostridium perfringens. E. coli

Pathogen recognition: tell me about pathogen associated molecular patterns (PAMPs)

1. molecular structures of microbes conserved within classes of microbes a. lipopolysaccharides (LPS) b. peptidoglycan (PGN) c. Lipotheichoic (LTA)

Dairy cow: staph aureus

1. most common cause of contagious mastitis in dairy herds a. heifers: major reservoir b. `3% of all animals infected 2. damage the duct system a. pocket infection, then abscesses and walling off of 45% per infected quarter, 15% infected cows 3. very chronic mastitis subclinical, although recurring clinical causes can occur a. low response to antibiotic treatment b. some stains produce an enzyme that inactivates antibiotics (B-lactamase)

Tell me about selective dry cow therapy

1. most herds benefit from a blanket approach (every quarter off every cow at dry off) a. 1 of the most effective strategies to minimize the number of infected quarters at calving b. problem: heavy use of antibiotics 2. selective dry cow a. low BTSCC b. monthly test with SCC and clinical mastitis records

Strep agalactiae: contagious pathogen

1. obligate parasite of mammary gland a. easy to eliminate if animals are IDd and treated 2. few clinical signs but high SCC and decreased milk production a. may have occasional flare-ups 3. infects cisterns and ducts a. produces irritant that causes inflammation-< damage to secretory tissue-> decreases milk yield

Tell me about the non-specific 2nd line of defense.

1. phagocytic leukocytes 2. antimicrobial proteins 3. inflammatory response 4. fever

How does the mammary gland respond to pathogens? (cellular factors) Killing mechanism

1. phagocytosis: intracellular pathogen killing in phagosomes via reactive oxygen species and/or antibacterial proteins 2. degranulation: release antibacterial protein extracellularly for killing extracellular pathogens 3. NETs: release of neutrophils extracellular traps- release DNA to immobilize

why would we see no growth?

1. possible reasons a. no infection 2. cows immune system eliminated bacteria before sample's taken 3. equipment failure 4. bacteria doesn't culture with easy culture system (ex mycoplasma) contamination

What is innate mammary defense?

1. predominant during early infection 2. activated quickly by numerous stimuli 3. can eliminate bacteria without changes in milk quality or quantity 4. depends on the efficiency of the inflammatory response

What happens when leukocytes arrive: what are neutrophils?

1. predominant leukocyte type during the initial stages of mastitis 2. can constitute 90% of total milk cell count

How can we manage heifer mastitis?

1. prevent cross-suckling 2. fly control 3. manage hygiene in heifer housing, not just cows 4. minimize stress around calving 5. if there is a high risk of environmental mastitis before calving, consider using internal teat sealants 6. use preparation antibiotic treatment per the herd vets recommendation

What are some considerations for medical history?

1. previous diagnosis of pathogen 2. history of repeated treatments for clinical mastitis 3. long history if chronically high monthly SCC (>200,000 Cell/mL) 4. occurrence of concurrent disease

How does the mammary gland respond: soluble factors: cytokines

1. produced by immune and non-immune cells 2. orchestrate host-defense, mechanisms 3. mediate inflammation 4. interferons (IFN), interleukins (IL), tumor necrosis factor (INF), growth factors, etc

Pathogen recognition: tell me about pattern recognition receptors (PRRs)

1. receptors on cells that recognize PAMPs 2. recognition results in initiating immune response

Tell me about monitoring

1. records a. bulk tank SCC b. monthly test data for individual cows SCC c. keep accurate and complete records (clinical) d. DHIA reports, dairy competition, PC-dart 2. Testing a. CMT b. individual culture c. bulk tank culture 3. california mastitis test a. cow-side indicator of SCC b. solution disrupts cell membranes and reacts with DNA i. cause thickening of solution 4. BT culture a. cant be used to estimate prevalence b. consider incorporating into regular herd health checks c. strategies for layer herds i. repeated sampling ii. string sampling (low number of cows sampled)

Tell me about subclinical mastitis

1. reduced production 2. loss of premiums $107/case

Tell me about clinical mastitis

1. replacement costs 2. discarded milk 3. reduced production 4. treatments

Tell me about gram positive gram staining

1. retains crystal violet stain a. cell wall is a thick peptidoglycan layer

Tell me about the specific 1st line of defense.

1. skin, mucous membrane 2. secretions of skin and mucous membrane

Environmental streptococci

1. ubiquitous environment, shed feeds in bedding a. high levels in straw bedding (strep uberis) 2. G+ 3.infections tend to be acute but can become chronic and about 40% present during lactation are self-cured 4. strep zooepidemicus: most common mastitis pathogen in mares 5. marin et al. 2017 (spain): strep isolated in 69% of samples from humans with mastitis

tell me about G intermediate gram staining

1. unpredictable response

When are SCCs detrimental?

1. when there is delayed migration to site of infection 2. when they are unable to control the rapid growth of bacteria in the udder 3. when elevated numbers persist for long periods of time

how are SCC necessary and helpful?

1. when they migrate rapidly and in sufficient numbers during the early stages of infection 2. when they function properly and eliminate bacteria effectively 3. when numbers return to low levels quickly

Tri-plate

L: modified TKt media a. strep and strep-like growth only R: MacConkey ,edia a. G- growth only D: factor media a. G+ growth only (Staph a grows on D) (strep AG grows on L)

How does the mammary gland respond: soluble factors: lactoferrin

a. produced by epithelial cells and leukocytes b. reversibly binds iron c. many bacteria require iron for growth (i.e. E. coli), so lactoferrin is released, which causes bacteria membrane disruption (bactericidal activity)

What has potential to prevent problems?

NSAID drugs have potential

What is the linear score

SCS=log2(SCC/100)+3

What happens when inadequate innate and adaptive immunity cause?

an increase in diseases like mastitis

Possible diagnosis: tell em about a bi-plate and tri-plate

bi: Growth or no growth a. G+ or G- b. staph a. present or not Tri: growth or no growth a. G= or G-. i. G+: staph v. strep b. staph a. present or not

What are the two options of mammary pathogen duration?

chronic and acute

What are the two options of symptoms in mammary pathogens?

clinical and subclinical

What happens when leukocytes arrive?

enact effector functions and removes bacteria

What is more likely in dry dairy cows, contagious or environmental mastitis?

environmental

What are the two mammary pathogen transmission types?

environmental and contagious

Dairy cow pathogens: environmental and contagious

environmental: coliform bacteria, and strep Spp (non-agalactiae) contagious: strep agalactiae, Staph a. mycoplasma spp.

Mastitis management: tell em about heifer weaning

warning signs: equal to or greater than 15% of the first parity have clinical mastitis around calving and 1 or equal to or greater than 15 5 of the 1st parity test SCC >150000 cells/ml

What is used for adaptive immunity pathogen recognition?

macrophages and dendritic cells present antigens to B and T cells