|
|
(11 intermediate revisions by 3 users not shown) |
Line 1: |
Line 1: |
− | {{review}}
| + | #REDIRECT[[:Category:Streptococcus species]] |
− | | |
− | {{toplink
| |
− | |backcolour =
| |
− | |linkpage =Bacteria
| |
− | |linktext =BACTERIA
| |
− | |pagetype=Bugs
| |
− | }}
| |
− | <br>
| |
− | | |
− | ===Overview===
| |
− | | |
− | *Cause suppurative infections in many different animals
| |
− | *Cause abscess formation and septicaemia
| |
− | *Cause mastitis, metritis, polyarthritis, meningitis
| |
− | *Often commensals on mucous membranes of upper respiratory and lower urogenital tract
| |
− | *Opportunistic infections
| |
− | | |
− | | |
− | ===Characteristics===
| |
− | | |
− | *Gram positive cocci forming chains
| |
− | *Catalase negative, facultative anaerobes
| |
− | *Fastitidious - require enriched media such as blood or serum
| |
− | *Small haemolytic, translucent colonies, some mucoid
| |
− | *Catalase negative
| |
− | *Susceptible to desiccation
| |
− | | |
− | | |
− | ===Identification===
| |
− | | |
− | *Beta haemolysis (complete with clear zones surrounding colonies)
| |
− | *Alpha haemolysis (partial with green zones surrounding colonies)
| |
− | *Lancefield grouping - serology based on group-specific polysaccharide in cell wall
| |
− | *Biochemical testing
| |
− | | |
− | | |
− | ===Pathogensis and Pathogenicity===
| |
− | | |
− | *Beta-haemolytic strains more pathogenic than alpha-haemolytic strains
| |
− | *Virulence factors include streptolysins, hyaluronidase, DNase, streptokinase and proteases
| |
− | *''S. pyogenes, S. pneumoniae'' and some strains of ''S. equi'' have polysaccharide capsules which are antiphagocytic
| |
− | *''S. pyogenes'' and ''S. equi'' have antiphagocytic cell wall M proteins
| |
− | | |
− | | |
− | ===Clinical infections===
| |
− | | |
− | *Primary or secondary infections following viral infection
| |
− | *Neonatal septicaemia related to maternal genital tract infection
| |
− | *Strangles
| |
− | **Highly infectious disease of horses caused by ''Streptococcus equi'' subsp. ''equi''
| |
− | **Upper respiratory tract disease with fever and abscessation of regional lymph nodes
| |
− | **Outbreaks in groups of young horses
| |
− | **
| |
− | | |
− | | |
− | ===Diagnosis===
| |
− | | |
− | *Swabs of pus or exudate cultured on blood agar and MacConkey agar
| |
− | *No growth on MacConkey except ''S. faecalis''
| |
− | *PCR, Lancefield grouping and biochemical tests
| |
− | | |
− | | |
− | ===Treatment===
| |
− | | |
− | | |
− | ===Control===
| |
− | | |
− | | |
− | | |
− | *Haemolytic streptococci of Lancefield group C are common inhabitants of the equine nasopharynx
| |
− | *''Streptococcus zooepidemicus'' and ''S. equisimilis'' are usually non-pathogenic
| |
− | *''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]]
| |
− | *''S. equi'' may be involved in [[Bacterial skin infections - Pathology#Systemic bacterial infections|cutaneous lesions]]
| |
− | [[Respiratory Bacterial Infections - Pathology#In Horses|URT inflammation in horses]]
| |
− | | |
− | * [[Peritoneal Cavity Inflammatory - Pathology#In pigs|peritonitis in pigs]]
| |
− | | |
− | *''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]]
| |
− | | |
− | *May cause [[Paranasal Sinuses Inflammatory - Pathology|sinusitis]] in horses
| |
− | | |
− | * Can cause vascular fragility, leading to [[General Pathology - Haemostasis#Haemorrhagic Disease Due To Vascular Fragility|haemorrhagic disease]].
| |
− | *Secondary invadors after [[Respiratory Viral Infections - Pathology#Equine influenza|Equine influenza]]
| |
− | *''S. suis'' in [[Respiratory Bacterial Infections - Pathology#Streptococcal pneumonia|pneumonia]] of pigs
| |
− | | |
− | *In [[Pleural Cavity & Membranes Inflammatory - Pathology#Pyothorax (Thoracic empyema)|pyothorax]]
| |
− | * In [[Bones Inflammatory - Pathology#Osteomyelitis|osteomyelitis]]
| |
− | | |
− | *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]]
| |
− | | |
− | *In horses sometimes [[Muscles Degenerative - Pathology#Ischaemia|purpura haemorrhagica]] follows, especially during recovery from [[Respiratory Bacterial Infections - Pathology#Strangles|strangles]]
| |
− | *In [[Cavity & Gingiva - Pathology#Catarrhal Stomatitis|catarrhal stomatitis]]
| |
− | | |
− | *In [[Bacterial skin infections - Pathology#Deep pyoderma|deep pyoderma]] and subcutaneous abscesses
| |