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| − | {{review}}
| + | #REDIRECT[[:Category:Streptococcus species]] |
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| − | {{toplink
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| − | |backcolour =
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| − | |linkpage =Bacteria
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| − | |linktext =BACTERIA
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| − | |pagetype=Bugs
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| − | <br>
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| − | ===Overview===
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| − | *Cause suppurative infections in many different animals
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| − | *Cause abscess formation and septicaemia
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| − | *Cause mastitis, metritis, polyarthritis, meningitis
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| − | *Primary or secondary infections following viral infection
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| − | *Neonatal septicaemia related to maternal genital tract infection
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| − | *Often commensals on mucous membranes of upper respiratory and lower urogenital tract
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| − | *Opportunistic infections
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| − | ===Characteristics===
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| − | *Gram positive cocci forming chains
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| − | *Catalase negative, facultative anaerobes
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| − | *Fastitidious - require enriched media such as blood or serum
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| − | *Small haemolytic, translucent colonies, some mucoid
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| − | *Catalase negative
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| − | *Susceptible to desiccation
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| − | ===Identification===
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| − | *Beta haemolysis (complete with clear zones surrounding colonies)
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| − | *Alpha haemolysis (partial with green zones surrounding colonies)
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| − | *Lancefield grouping - serology based on group-specific polysaccharide in cell wall
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| − | *Biochemical testing
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| − | ===Pathogensis and Pathogenicity===
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| − | *Beta-haemolytic strains more pathogenic than alpha-haemolytic strains
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| − | *Virulence factors include streptolysins, hyaluronidase, DNase, streptokinase and proteases
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| − | *''S. pyogenes, S. pneumoniae'' and some strains of ''S. equi'' have polysaccharide capsules which are antiphagocytic
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| − | *''S. pyogenes'' and ''S. equi'' have antiphagocytic cell wall M proteins
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| − | ===[[Respiratory Bacterial Infections - Pathology#Strangles|Strangles]]===
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| − | *Epidemiology
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| − | **[[Respiratory Bacterial Infections - Pathology#Strangles|Strangles]] is a highly infectious disease of horses caused by ''Streptococcus equi'' subsp. ''equi''
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| − | **Upper respiratory tract disease with fever and abscessation of regional lymph nodes
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| − | **Outbreaks in groups of young horses
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| − | **Transmitted via purulent exudate discharging from upper respiratory tract or from lymph nodes
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| − | **Chronic, carrier state can occur with bacteria im the guttural pouch
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| − | **A mild, atypical form can occur
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| − | **''S. equi'' shed for 4 weeks beyond clinical resolution
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| − | *Clinical signs
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| − | **Incubation period 3 to 6 days
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| − | **Fever, depression, anorexia
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| − | **Purulent nasal discharge
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| − | **Swollen, painful regional lymph nodes, especially submandibular
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| − | **Abscessation and rupture of lymph nodes
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| − | **Guttural pouch empyema
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| − | **100% morbidity; 5% mortality
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| − | **Death can occur from pneumonia, breathing difficulties from swollen lymph nodes or [[Muscles Degenerative - Pathology#Ischaemia|purpura haemorrhagica]](an immune-mediated disease)
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| − | **Bastard strangle may occasionally occur, with abscessaation in many organs of the body
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| − | *Diagnosis
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| − | **Clinical signs and history
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| − | **Mucoid colonies with beta-haemolysis
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| − | **Sugar fermentation allows differentiation of ''S. equi'' from ''S. zooepidemicus'' and ''S. equisimilis''
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| − | **PCR to detect asymptomatic carriers
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| − | *Treatment and control
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| − | **Penicillin administration to in-contact animals
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| − | **Isolation of affected animals
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| − | **Quaranteen in-coming animals
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| − | **Avoid overcrowding and mixing different age groups
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| − | **Disinfection of equipment
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| − | ===''Streptococcus suis''===
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| − | *Meningitis, arthritis, septicaemia and [[Respiratory Bacterial Infections - Pathology#Streptococcal pneumonia|pneumonia]] of pigs
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| − | *Sporadic cases of endocarditis, neonatal deaths and abortion
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| − | *Carried in tonsils of carrier pigs
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| − | *Outbreaks occur in intensively-reared herds with poor hygiene
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| − | *Carrier sows infect litters causing neonatal deaths
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| − | *Meningitis with fever, tremors, incoordination, opisthotonos and convulsions
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| − | *Treatment with penicillin; prophylactic long-acting penicillin for sows and piglets
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| − | ===Bovine streptococcal mastitis===
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| − | *''S. agalactiae, S. dysgalactiae'' and ''S. uberis'' primarily cause mastitis
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| − | *Also ''S. pyogenes, S. zooepidemicus'' and ''Enterococcus faecalis'' can be involved
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| − | *''S. agalactiae colonises milk ducts causing persistent infections with acute outbreaks
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| − | *''S. dysgalactiae'' found in the oral cavity and on the skin of the udder causes acute mastitis
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| − | *''S. uberis'' inhabits normal skin, tonsils and vaginal mucosa, and causes mastitis without systemic signs
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| − | *Cause inflammation of mammary tissue and clots form in milk
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| − | *Milk samples are cultured on blood agar, Edward's medium and MacConkey agar for diagnosis
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| − | ===Diagnosis===
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| − | *Swabs of pus or exudate cultured on blood agar and MacConkey agar
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| − | *No growth on MacConkey except ''S. faecalis''
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| − | *PCR, Lancefield grouping and biochemical tests
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| − | *Haemolytic streptococci of Lancefield group C are common inhabitants of the equine nasopharynx
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| − | *''Streptococcus zooepidemicus'' and ''S. equisimilis'' are usually non-pathogenic
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| − | *''S. equi'' is more pathogenic and is the cause of [[Respiratory Bacterial Infections - Pathology#Strangles|strangles]] with [[Nasal Cavity Inflammatory - Pathology#Strangles|rhinitis]], [[Nasopharynx Inflammatory - Pathology|pharyngitis]], lymphadenitis, [[Muscles Inflammatory - Pathology#Abscesses|myositis]]
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| − | *''S. equi'' may be involved in [[Bacterial skin infections - Pathology#Systemic bacterial infections|cutaneous lesions]]
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| − | [[Respiratory Bacterial Infections - Pathology#In Horses|URT inflammation in horses]]
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| − | * [[Peritoneal Cavity Inflammatory - Pathology#In pigs|peritonitis in pigs]]
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| − | *''S. zooepidemicus'' can cause similar signs to [[Respiratory Bacterial Infections - Pathology#Strangles|strangles in horses]], may accompany [[Bronchi and Bronchioles Inflammatory - Pathology#Chronic obstructive pulmonary disease (COPD)|COPD]]
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| − | *May cause [[Paranasal Sinuses Inflammatory - Pathology|sinusitis]] in horses
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| − | * Can cause vascular fragility, leading to [[General Pathology - Haemostasis#Haemorrhagic Disease Due To Vascular Fragility|haemorrhagic disease]].
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| − | *Secondary invadors after [[Respiratory Viral Infections - Pathology#Equine influenza|Equine influenza]]
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| − | *In [[Pleural Cavity & Membranes Inflammatory - Pathology#Pyothorax (Thoracic empyema)|pyothorax]]
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| − | * In [[Bones Inflammatory - Pathology#Osteomyelitis|osteomyelitis]]
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| − | *In infectious [[Joints Inflammatory - Pathology#In Sheep|arthritis of sheep]], [[Joints Inflammatory - Pathology#In Cattle|arthritis in calves]], [[Joints Inflammatory - Pathology#In Horses|arthritis in horses]] and [[Joints Inflammatory - Pathology#In Pigs|arthritis in pigs]]
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| − | *In [[Cavity & Gingiva - Pathology#Catarrhal Stomatitis|catarrhal stomatitis]]
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| − | *In [[Bacterial skin infections - Pathology#Deep pyoderma|deep pyoderma]] and subcutaneous abscesses
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