Streptococcus suis infection

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Streptococcus suis infection

• Pornpen Pathanasophon

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Contents

• Streptococci of veterinary and medical
  significance
• Disease characteristics in pigs
• Predisposing factors
• Mode of transmission
• Virulent factors
• Laboratory diagnosis
• Carrier stage in pigs Antimicrobial
  susceptibility

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Streptococci of veterinary and medical
significance
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Streptococci of veterinary and medical
significance
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Streptococcus suis infection in pigs Disease
status

• World wide in pig raising industry

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Disease characteristics in pigs

• Menigitis
• Pneumonia
• Polyserositis
• Endocarditis
• Polyarthritis
• Septicemia
• Abortion

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Predisposing factors Stress

• Poor management
• Too much cloudy in a pen
• Change in ambient temperature
• Movement of pigs within a farm or between farms
• Weaning
• Vaccination
• Predisposed by other bacteria or viral infections
  

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Pathogenesis

• Piglets from new born until weaning are most
  susceptible
• Invasion of bacteria from tonsil through
  lymphatic system to lower jaw lymph node
• Septicemia
• Encephalitis, meningitis

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Mode of Transmission

• The bacteria hided in upper respiratory tract,
  nostril, palatine tonsil, feces without clinical
  sign
• Infection from vagina of sows through umbilical
  cord or milk suckling
• Wound from tail or ear cutting, vasectomy,
• abrasion skin
• Movement from infected herd to innocent herd
• Stable fly or mouse may through mechanical
  transmission

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Carrier rate of S. suis capsular type 2 in
palatine tonsil

• 32 50 in 143 slaughter pigs, 4-6 mts age (In
  the Natherlands, Arends et al., 1984)
• 24 in 122 pigs 3-8 wk (In England,
  Clifton-Hadley and Alexander, 1980)
• 18 in 52 pigs unspecific age (In Germany,
  Clausen, 1980)

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Transmission from animal to human

• Ingestion of uncooked meat or blood from infected
  animals
• Through wound or abrasion skin

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Virulence factors

• Fimbriae (Jacques et al., 1990)
• Polysaccharide capsules
• (Charland et al., 1998)
• Muramidase releasing protein (MRP) and
  extracellular factor (EF)
  (Vecht et al., 1991, 1996)
• Suilysin (Jacobs et al., 1994)
• Dnase (extracellular nuclease)
  (Fontaine et al., 2004)

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Clinical signs

• High prevalent at 5-6 wk old
• Septicemia
• Central nervous systems, convulsion
• Mortality 2-3
• Mortality 10-20 in S. suis PRRS

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Clinical signs

• High fever 103-104 oF, red eyes
• Septicemia
• Respiratory system cough sneezing respiratory
  distress, pneumonia
• Poly-arthritis with pus and pain
• Central nervous systems tremor, convulsion

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Gross pathology

• Purulent meningitis and thickening
• Hyperemia and hemorrhage

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Gross pathology

• Purulent arthritis

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Fresh smear from brain

• Streptococcus in brain tissue
• Gram positive cocci

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Resistance of S. suis type II in the environment

• 60oC 10 min
• 50oC 2 h
• Carcass at 10oC 6 w
• Dust at 0oC 1 m
• Dust at 25oC 24 h
• Feces at 0oC 3 m
• Feces at 25oC 8 d

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Laboratory diagnosis

• Bacterial isolation and identification
• - Conventional method
• - Rapid API strep system
• - PCR
• Capsular type (polysaccharide)
• by Lancefield, 1933

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Conventional method

• Facultative aerobic
• Colony morphology
• Size bout 1 mm after 48 h incubation
• Gram positive cocci, pair or chain
• ? hemolysis
• Biochemical tests are highly variable

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Rapid API strep system

• Rapid within 24 h
• Expensive about B 360 per isolate
• S. suis I /S. suis II differentiate by raffinose
• 20 of S. suis field isolates can not be
  identified by API but be identified as
  S. pneumoniae
• S. suis ? - glucuronidase pos.
• S. pneumoniae ? - glucuronidase neg.
• (Gottschalk et al. 1991)

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Colonies on blood agar (48 h)
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Laboratory test by PCR

• Streptococcus suis
• Serotype 1, 2, 7, 9
• Suilysin production

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Treatment

• Separate the sick animals
• Antimicrobial treatment ampicillin, ampicillin
  clavulanic acid, penicillin, cephalexin,
  Ciprofloxacin (Data from NIAH)

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Control

• Antimicrobial drug in piglets feed during and
  after weaning (5-7 wk age)
• - Amoxicillin 200-300 ppm.
• - Ampicillin 200-300 ppm.
• - Sulfa-Trimethoprim 250-300 ppm.
• - Fosfomycin 200 ppm.
• - Cefthiazole 200 ppm.
• (data from Dr Kijja)
• Vaccination

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Laboratory specimens

• Internal organs heart, liver, lung, kidney
• Brain
• Pus in affected joint
• Aborted fetus
• Uterus
• Milk from inflammatory udder (s)

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?????????????? 2 ??? ??? 7 ?? 2550
F farm, S slaughter house
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???????????????? 2 ??? ??? 7 ?? 2550
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??????????????????????????????????????????
Streptococcus suis ??? swab ??????????????????????
??????????????????????? 2 ?????? 7 ?? 2550
(n286)
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Streptococcus suis II ??? swab ???????????????????
?????????????????????????? 2 ?????? 7 ?? 2550
(n286)
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The End

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