Mastitis continued again!

Question 1

Streptococcus uberis
haemolytic?
Agar?

Answer 1

Non haemolytic
Brown colonies on Edwards medium
Gram positive

Question 2

Source of streptococcus iberis
Type of pathogen
What increases risk

Answer 2

Source =bovine faeces, t

Environmental pathogen (ubiquitous in the environment) but also contagious pathogen (cow adapted strains found in tonsils, genital tract, rumen)

At least 250 strains
Straw yard housing
Straw bedded cubicles
Muddy fields at end of summer / crowded area e.g. shade, water = contaminate area with faeces = environemntal organissm build up

Question 3

Streptococcus uberis
What grades of mastitis can it cause?
What type of infection?

Answer 3

Mastitis can occur all grades and all stages of lactation – rarely peracute grade 3

Persistent sub-clinical infection is common (grumbling high cell count cows)
Recurrent clinical cases common

Clinical mastitis cases: DNA fingerprinting of Streptococcus uberis has shown:
many strains on 1 farm but usually one predominant strain
persistent infections: particular strains
chronic infections: particular strain

Question 4

What is similar about strepto aureus and uberis

Answer 4

Both sit around - grumbling

Both can live intracellularly = sneaky

Question 5

Virulence/ pathogenesis of Streptococcus iberis

Answer 5

Intracellular (mammary epithelial cells) ;avoid detection by immune system
SUAM adhere to mammary epithelial cells
Hyaluronic acid capsule : protective shell prevents attachment of antibodies or the neutrophils
After phagocytosis some strains can resist killing by neutrophils
May inhibit PMN ability to produce pseudopodia

Question 6

Control streptococcus uberis

Answer 6

Infection particularly common during dry period and early lactation
Housing hygiene of environment (dry and milking)
Muddy fields/ tracks
Control
Pre-milking teat preparation
Milking order
Cull chronic cases
Dry Cow Therapy, give antibiotics

Question 7

Summer mastitis
affects:
What time?
Spread by what?
Near what environment?

Answer 7

a syndrome on its own, both dairy and beef

affects heifers, dry, suckler etc…. any cow!
spread by flies
woodlands big risk

Typically affects DRY cows and HEIFERS OUT DOORS IN SUMMER in fields but is also seen occasionally in steers and bulls and can occur in housed cows in winter

Question 8

What summer mastitis does it affect udder wise

When is it noticed?

Answer 8

Affects usually 1 quarter, abscess, destroys quarter
doens’t affect ssytemically often
only noticed when enters milking herd and one of the quarter isn’t producing milk

Question 9

Clinical sings of summer mastitis

Answer 9

hot hard swollen very painful udder with a thick purulent secretion. The cow may also be lame and systemically ill
Mild cases do occur and are only noticed as cow calved down with blind teat end or with a mild case of mastitis from which T. Pyogenes is cultured

Question 10

Milking order to minimise transmission

Answer 10

1st parity heifers first
Healthy cows next (SCC low)
High SCC cows
Cows with clinical mastitis

INPRACTICAL

focus on disinfecting cluster