Lesson 2b; streptococcus species Flashcards
also known as pneumococcus, it occurs as slightly pear-shaped cocci in pairs.
streptococcus pneuminiae
peptinophilus indolicus is an anaeobic gram positive, which is implicated in bovine summer mastitis in association with what?
Arcanobacterium pyogenes & S. dysgalactiae
where is the usual habitat of the streptococcus species?
- mucosae of the upper respiratory tract
- lower urogenital tract; suspectible to dessication
what are the laboratory differentiation:
- hemolysis
- lancefield grouping
- biochemical testing
is complete haemolysis indicated by clear zones around colonies
Beta-haemolysis
is partial or incomplete haemolysis indicated by greenish or hazy zones around colonies
Alpha-haemolysis
denotes no observation changes in the blood agar around colonies
Gamma-haemolysis
_____ is non-pyogenic & is a major pathogen of pigs, septicaemia, meningitis & pneumonia
Streptococcus suis
_______ are generally more pathogenic than those producing alpha-haemolysis
Beta-haemolytic streptococci
what are the virulence factor in streptococcus species?
- enzymes
- exotoxins
- streptolysins (haemolysins)
- hyaluronidase
- NADase
- DNase
- streptokinase
- proteases
______ major virulence factor of S. pyogenes, S. pneumoniae, & most strains of s. equi, this are antiphagocytic that protects them from phagocytes.
Polyaccharide capsules
in terms for diagnosis specimens should be cultured on?
- blood agar
- selective blood agar
- MacConkey agar
in horses streptococcus equi, a febrile disease invloving the upper respiratory tract w/ abscessation of regional lymph nodes.
Strangles
what is the tx for strangles?
penicillin & vaccine
What is most common streptococcus species ?
S. equi subsp. eqiu in horses
In S. equi subsp. equi in horses it causes:
- Strangles suppurative
- Purpura hemorrhagica
where is the usual habitat of S. equi subsp. equi:
- upper respiratory tract
- guttural pouch
pyogenic characteristics causes:
- Abscess formation
- Suppurative lesions
- Septicemia
What is the diagnoses? note that it should be processed immediately as it easly destroyed by dessication:
Swab camples collected from pus or exudates
specimen should be cultured on:
- Blood agar
- Selective blood agar
- MacConkey agar
identification criteria in diagnosis:
- Small translucent colonies (some maybe mucoid)
- Type of haemolysis on blood agar
- Chains of gram positive-cocci
- No growth on MacConkey agar
- Negative catalase test: Lancefield grouping or Biochemical test profile
In streptococcus suis infection: Asymptomatic carrier pigs harbous S. suis in?
Tonsillar tissue
Streptococcus suis infection are most common in intensively reared pigs when they are subjected to:
- Overcrowding
- poor ventilation
- stress factors
______ is fatal & is characterized by fever, tremors, incoordination, opisthotonos & convulsions.
Meningitis
