Porcine Pathogens Flashcards
List 11 zoonotic Pig Pathogens
- Brachyspira pilosicoli
- Brucella suis
- Camplylobacter spp.
- Clostridioides difficile
- Clostridium perfringens type A
- E. coli
- Erysipelothrix rhusiopathiae
- Leptospira spp.
- Salmonella spp.
- Staphylococcus spp.
- Streptococcus spp.
List 9 risk factors for bacterial infections in pigs
- Drafts
- Improper temperature/fluctuations
- Inadequate ventilation
- Excess humidity (also NH3/CO2)
- Overcrowding
- Fighting
- Nutritional inadequacies
- Mixing of pig types (age/size)
- Secondary to major pathogens like PRRSV/swine influenza virus/PCV2/Mycoplasma spp./Lawsonia intracellularis
List 9 common clinical manifestations/consequences of bacterial infections in pigs
- Sepsis
- Acute death/septicemic shock
- Meningitis
- Inner ear infection
- Arthritis
- Pleuritis
- Pericarditis
- Endocarditis
- Pneumonia
What are 4 common causes of systemic bacterial pig infections
Systemic
* Diamond skin disease
* Suis-ides
* Strep zooepidemicus
* Mycoplasma hyorhinis
Resp
* Atrophy rhinitis
* Pleuropneumonia
* Bronchopneumonia
What are 2 clinical manifestations of urogenital bacterial pig infections
Urogenital: abortion/cystitis
What is 1 common cause of integument bacterial pig infections
Integument: greasy pig disease (Step hyicus)
What are 5 common clinical manifestations and bacterial causes of GI bacterial pig infections
- Neonatal/post weaning
o Scours (E. coli – ETEC, edema dz/clostridium perfringens A/C or difficile/salmonella) - Grower/finisher
o Swine dysentery (brachyspira hyodysentariae or hampsonii)
o Spirochetal colitis (brachyspira piloscoli)
o Proliferative enteropathy (lawsonia intracellularis)
o salmonella
What are 6 common clinical manifestations and bacterial causes of resp bacterial pig infections
- Primary
o Pleuropneumonia (actiniobacillus pleuropneumoniae)
o Bronchopneumonia (myocoplasma hyopneumoniae/e. coli) - Secondary
o Atrophy rhinitis (P. multicide and B. bronchiseptica)
o Actinobacillus suis
o Glaesserella parasuis
o Strep suis
What are the general clinical consequences of systemic bacterial pig disease
- Clinically: reflect systemic disease (fever/anorexia/depression)
Compare the causative agents of systemic pig diseases of nursery vs grower/finisher pigs
- Life stages
o Nursery: G. parasuis/S. suis/M. hyorhinis
o Grower/finisher: A. suis/M. hyopneumoniae/E. rhusiopathiae
Pneumonic agents more common
what is the main lesion of systemic pig diseases
- Lesions: polyserositis +/- arthritis
What is the causative agent of Diamond skin disease
- Diamond skin disease (erysipelothrix rhusiopathiae = erysipelas)
What the gram type and shape of erysipelothrix rhusiopathiae
o Gram (+) rod
Where is erysipelothrix rhusiopathiae found? What are the main hosts and reservoirs
o Worldwide
o Animal hosts: terrestrial and marine mammals/bird/reptile/fish/arthropod
o Reservoir: pig tonsils and intestinal tract
Why is doing serology on systemic bacterial pig pathogens important
because you can identify serotype and make autogenous vaccines
What are 2 virulence factors of erysipelothrix rhusiopathiae
o Virulence
Neuraminidase
Capsular polysaccharide
How is erysipelothrix rhusiopathiae transmitted
o Transmit: direct contact or fomites (feed/water/soil/bedding)
Pigs shed LOTS
How to package sample for PCR
no liquid sample media
What is the pathogenesis of erysipelothrix rhusiopathiae
o Pathogenesis
Oral/skin exposure + tonsil/GI abrasion
Bacteria survive and replicate in macrophage
Bacteremia
Septicemia
Widespread vasculitis/fibrinous thrombosis/diapedesis/necrosis
What are the 3 types of erysipelothrix rhusiopathiae manifestation?
Acute: septicaemic disease
Subacute: less severe +/- subclinical, few or no skin lesions
- Chronic arthritis and firm enlargement of hock/stifle/carpal
What are the lesions associated with the 3 types of erysipelothrix rhusiopathiae manifestations?
Acute: septicaemic disease with raised pink/red/purple diamond lesions
Subacute: less severe +/- subclinical, few or no skin lesions
Chronic: after acute/subacute/subclinical
- Chronic arthritis and firm enlargement of hock/stifle/carpal
- Respiratory distress = cyanosis or sudden death – vegetative valvular endocarditis
How is erysipelothrix rhusiopathiae diagnosed? What samples to take and what testing is used?
o Diagnose
Sample: blood filtering organs – liver/spleen/kidney or joint tissue
More chronic = harder to detect bacteria
Tests: culture and susceptibility
* Serotyping/IHC/in situ hybridization/PCR
What are 5 differentials for acute (septicemic) erysipelothrix rhusiopathiae
Acute = septicemia/sudden death in growers/finishers
* Salmonella
* Actinobacillus suis
* Actinoobacillus pleuropneumoniae
* Glasserella parasuis
* Strep suis
What are 3 differentials for skin lesions associated with erysipelothrix rhusiopathiae
Skin lesions
* CSF
* porcine dermatitis and nephropathy syndrome
* actinobacillus suis septicemia
What are 2 differentials for Vegetative valvular endocarditis associated with erysipelothrix rhusiopathiae
Vegetative valvular endocarditis
* Strep suis
* Actiinobacillus suis
List 3 types of Suis-ides
o Strep suis
o Glaesserella parasuis = glassers disease
o Actinobacillus suis
What is the gram type and shape of strep suis? What is important about their serotyping?
o Strep suis
Gram (+) cocci
Many serotypes: type 1 and 2 most important (associated with septicemia/meningitis/arthritis)
Where is strep suis found? How is it transmitted?
Commensal in upper rest
Transmit: direct contact/aerosols
* 3-10 week old piglets (after wean) most susceptible – stress/decrease in maternal Ig
What are 2 virulence factors of strep suis
- Capsular polysaccharide
- Hemolysin suilysin which is toxic to epithelial/endothelial/phagocytes
What is the pathogenesis of strep suis
- Colonize tonsils and upper resp
- Invade resp mucosa + uptake and adhere to monocytes
- Capsule resists phagocytosis + cause bacteremia
- Release inflammatory mediators and cause septic shock
- Invade endothelial cells and multiply in subarachnoid space
- Cause inflammation and increases BBB permeability resulting in cerebral edema
- Increased intracranial pressure reduces circulation
- CNS dysfunction
What bodily structures are affected by strep suis
- Nasal cavities/saliva/tonsils
- CSF/meninges
- Heart
- Joint
- Lung
- Intestine
- Blood
- Genital tract
What are the clinical signs of strep suis
- Non specific
- Septicemia
- Neurologic
What are the 3 clinical types of strep suis and what are the clinical manifestations
- Peracute = sudden death (septic shock)
- Acute = septicemia/meningitis/polyserositis/polyarthritis
- Chronic = arthritis/vegetative valvular endocarditis/myocarditis/bronchopneumonia
What are the main lesions associated with strep suis
Lesions
* Meningitis
* Arthritis
* Endocarditis
* Polyserositis
* Petechial hemorrhage
How is strep suis diagnosed? What samples to take and what testing is used?
- Sample: heart (+/- valves)/lung/liver/spleen/kidney/fibrinous exudate/brain/synovium and joints
o If CNS signs = brain sample is most important - Testing: C/S (or serotyping – make autogenous vx)
What are the differential diagnoses associated with strep suis lesions?
DDX
* Polyserositis: G. parasuis/M. hyorhinis
* Meningitis: G. parasuis
* Endocarditis: E. rhusiopathiae/A. suis
* Septicemia: G. parasuiss/A. suis/ E. rhusiopathiae/salmonella
* Polyarthritis: M. hyorhinis/M synoviae/ E. coli/staph/strep
What is the gram type and shape of Glaesserella parasuis? What is an important feature to know about it
Gram (-) rod
Fastidious (not viable at room temp for very long)
What are the virulence factors associated with Glaesserella parasuis?
Virulence
* LPS endotoxin
* Capsular polysaccharide
How is Glaesserella parasuis transmitted
Transmit: direct contact
High morbidity and high mortality – all age
What is the pathogenesis of Glaesserella parasuis?
Pathogenesis
* Nasal cavity/trachea = colonize
o stress induced or secondary to viral infection
* epithelial invasion/replication
* septicemia
What are the 3 clinical types of Glaesserella parasuis?
- Peracute
- Acute
- Chronic
What are the lesions associated with Glaesserella parasuis?
- Peracute = sudden death within 2 days
o No gross lesions +/- petechia in some organs - Acute = high fever/swollen joints/CNS signs
o Fibrinous-fibrinopurulent polyserositis
o Polyarthritis
o meningitis - Chronic = mild (rough hair/poor growth/lame/cough)
o Severe fibrosis
o Arthritis
How is Glaesserella parasuis diagnosed? What samples to take and what testing is used?
Diagnose
* Sample: lung/hear/liver/spleen/kidney/brain/synovium orr joint
* Test: C/S (also serotype/PCR/IHC/ISH)
What is the gram type and shape of Actinobacillus suis? Where is it found?
Gram (-) rod
Opportunistic and ubiquitous – found in tonsil/upper resp
What are the virulence factors of Actinobacillus suis
Virulence
* Capsular polysaccharide
* OmpA – adhesions to brain microvascular endothelial cells
What is the pathogenesis of Actinobacillus suis
Unknown pathogenesis – involves systemic septic emboli
* Higher prevalence in new herds
What are the clinical signs of Actinobacillus suis
Clinically
* Sudden death
* Lame
* Fever
* CNS signs
What are the 3 clinical types of Actinobacillus suis and what age groups are they most prevelent
- Acute fulminant septicemia:
Neonates/recently weaned - Resp: grower and finisher
- Septicemia: adults
What are the lesions associated with the different types of Actinobacillus suis
- Acute fulminant septicemia:
o Neonates/recently weaned - Resp:
o Cough/fever
o Hemorrhagic/necrotizing pneumonia or pleuropneumonia - Septicemia:
o Lethargy/anorexia/diamond skin lesions like erysipelas/lame/abortion/metritis/death
o Serous-Sero fibrinous exudate
o Petechia/ecchymotic hemorrhage on organs
o Pleuritis
o Pericarditis
o arthritis
What are the general lesions associated with Actinobacillus suis
Lesions
* Septicemia
* Respiratory pneumonia
* Ischemic rhomboid skin lesions
* Valvular endocarditis and arthritis
How is Actinobacillus suis tested for? What samples are used
Diagnose
* Sample: lung/brin/spleen/liver/kidney/heart (+/- valve)/synovium or joint
* Test: C/S
What are 3 common differentials for Actinobacillus suis
DDX: actinobacillus pleuropneumonia/erysipelothrix rhusiopathiae/Strep suis
Compare the ‘suis’ diseases with Actinobacillus pleuropneumoniae
o ‘suis’ diseases vs Actinobacillus pleuropneumoniae
Suis diseases are multisystemic
APP affects lung primarily
What is the gram type and shape of Strep equi zooepidemicus
o Gram (+) cocci
What are the 3 main virulence factors of Strep equi zooepidemicus
Capsular polysaccharide
Hyaluronidase
Streptolysin S
How is Strep equi zooepidemicus transmitted
o Transmit: direct contact/aerosol
What are the clinical signs of Strep equi zooepidemicus
o Clinically: fever/lethargy/abortion/sudden death
1-3 week old piglets = septicemia
What are the main lesions of Strep equi zooepidemicus
o Lesion:
Splenomegaly
Fibrous peritonitis
(also petechia/hemorrhagic lymphadenopathy
How is Strep equi zooepidemicus tested for and what are the samples needed
o Diagnose
Sample: liver/kidney/heart/lung/spleen/brain
Test: C/S
Where is Mycoplasma hyorhinis found? What animals does it affect?
- Mycoplasma hyorhinis
o Commensal of tonsil/resp epithelium
o Affect nursery age pig
What is the virulence factor of Mycoplasma hyorhinis
Lipoproteins to stimulate cytokine production
How is Mycoplasma hyorhinis transmitted
o Transmit: direct contact with nasal secretions
What is the pathogenesis of Mycoplasma hyorhinis
Bacteria bind ciliated respiratory epithelium (nose/conducting airway)
* Lipoproteins embedded in host cell membrane
Systemic invasins occurs at mucosal colonization
Mechanism of invasion in unknown
What are the clinical signs associated with Mycoplasma hyorhinis
o Clinically: 3- 10 weeks
Non specific (lethargy/anorexia)
Resp – dyspnea
Arthritis – swelling of joints/lame
What are the main lesions associated with Mycoplasma hyorhinis
Fibrinous serositis
Edematous and fibrinosuppurative exudate in synovial membranes
How is Mycoplasma hyorhinis tested for and what samples are used?
o Diagnose
Sample
* Fibrin/swab from serosa
* Fibrin/swab/fluid from joint
* Fluid from body cavities
Test – PCR
What can you not use to treat Mycoplasma hyorhinis and why?
o Tx: cannot use beta lactams (no cell wall)
Limited ability to do C/S
What are common differentials for the clinical manifestations of Mycoplasma hyorhinis
Polyserositis/polyarthritis: G. parasuis/S. suis/A. suis
Arthritis: mycoplasma synoviae
What is the gram type and shape of Actinbaculum suis? What is its growth requirement?
Actinobaculum suis
o Gram (+) rod – anaerobic
o Require alkaline conditions for growth
Where is Actinobaculum suis found?
o World wide – commensal of boar prepuce
What are the virulence factors for Actinobaculum suis
Adhesions
Produce urease
How is Actinobaculum suis transmitted?
o Transmit: direct (mating with infected boar)
1-3 weeks to develop infection in female
Less prevalent because AI more common
What is the pathogenesis of Actinobaculum suis
o Pathogenesis
Alkalosis in urine
Bacterial growth and migration
Poor hydration = crystalluria
Urease production
Damage bladder
Ascending infection in ureter/kidney
What are the clinical signs associated with Actinobaculum suis
cystitis/pyelonephritis/metritis
sudden death
What are the 3 phases of infection of Actinobaculum suis
Acute = hematuria
Later = blood stained purulent urine
Mild = anorexia and vaginal discharge
How is Actinobaculum suis tested for and what samples are used?
Sample: urine/bladder/kidney/purulent fluid/vaginal discharge/semen
Test: anaerobic culture
How is Actinobaculum suis infection treated
o Tx: ampicillin/penicillin/tetracycline
