7. Streptococcocis

What is the general characteristic of Streptococcus bacteria?

Streptococcus bacteria are gram-positive, non-motile, facultative anaerobic spherical microbes.

Where can many streptococcal species be found in the body?

Many streptococcal species are part of the commensal microbiota of the mouth, skin, intestine, and upper respiratory tract.

When can streptococcal disease occur?

Streptococcal disease may occur when the bacteria enter cuts, abrasions, wounds, or when the immune system becomes weakened. Streptococcus can be the sole causative agent in such cases.

How can streptococcal infections spread between animals?

Streptococcal infections can spread between animals through direct contact, aerosol transmission, fomite transmission, and sometimes ingestion.

What are some diseases associated with streptococcal infections in animals?

Diseases associated with streptococcal infections include strangles, neonatal infections, meningitis in pigs, lymphadenitis in pigs, avian streptococcosis, streptococcosis in dogs and cats, and mastitis.

What are the characteristics of streptococcal infections in young animals?

Streptococcal infections in young animals can cause purulent local inflammatory processes that result in systemic diseases. The involvement of multiple organs can lead to fatal septicaemia

What is the aetiology for porcine meningitis?

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**S*****tr. Suis type 2*** **–** **serogroup R**. Causing meningitis, septicaemia, arthritis. Young animals **3-12 weeks**. **Zooantroponosis! = Man to animal**

What is the epizootiology of porcine meningitis?

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Global problem that can be isolated on all pig farms. Sources of infection – **healthy animal (tonsils, nasal mucosa, vagina**)

Persistency – in tonsils more than 1yr

What are the hosts of porcine meningitis?

Host – **swine, 10-14 days post weaning**, cattle, sheep, goats, man

What is the transmission of porcine meningitis?

**direct contact, aerosol, mother-young**, among piglets and newborns in close contact with sow

What is the pathogenesis of porcine meningitis?

Port of entry **– tonsils** 

Young animals – **septicaemia, joints** 

Older animals – **meningitis, endocarditis** which can be fatal depending on condition of animals 

Predisposition - Management and husbandry stresses

After oral or respiratory entry, streptococci pass to the crypts of the palatine tonsils. From there the organisms invade via lymphatics to the mandibular lymph nodes where they can remain localized or become septicaemic. Some organisms may survive within phagocytes and gain access to cerebrospinal fluid, brain, meninges, lungs, and joints where they localize and cause **meningoencephalitis, arthritis, or pneumonia**

What is the incubation period of porcine meningitis?

24 hours - 2 weeks

What are the clinical signs of porcine meningitis?

Sudden death of piglets, or death after signs including fever, anorexia, depression, tremors, ataxia, convulsions, and blindness. **Sitting position is common with meningitis**

If arthritis is present, piglets show lameness and swelling. 

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Endocarditis of older pigs (\~13 weeks) causes death without clinical signs.

What is the diagnosis for porcine meningitis?

Clinical signs, necropsy, and **isolation of organism** from CSF, brain, lungs, synovial fluid, or heart.

Must carry out lab diagnosis to **differentiate from ASF**

What is the treatment for porcine meningitis?

Antibiotics, vaccination is not effective

What is the prevention against porcine meningitis?

hygiene, quarantine

What is the aetiology of avian streptococcosus?

Str. Equi zooepidemicus; dysgalatiae; gallinaceaus; mutans

What are the hosts of avian streptococcosis?

poultry, pigeons

What is the transmission for avian streptococcosis?

Aerosol, oral, skin injuries

What are the clinical signs of avian streptococcosis?

Localised or septicaemic.

**Endocarditis, lameness** in subacute or chronic phase

S. equi zooepidemicus: acute septicaemia, lethargy, egg production reduced by 15%

Chronic infections: arthritis, tenosynovitis, osteomyelitis, salpingitis, pericarditis, myocarditis, valvular endocarditis

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Pathology: splenomegaly, hepatomegaly, enlarged kidneys

What is the diagnosis for avian streptococcosis?

Clinical signs, necropsy, and **isolation of organism from CSF, brain, lungs, synovial fluid, or heart.**

Blood culture from lesion sample or impression smears 🡪 **blood agar**

What is the treatment for avian streptococcosis?

Antibiotics (**erythromycin**), vaccination is not effective

What is the prevention against avian streptococcosis?

Hygiene, quarantine, prevent skin damage

Which species of Streptococcus affect humans?

Group A streptococci

Tonsilitis, scarlatina, erysipelas, impetigo. Rheumatic fever, glomerulonephritis. 

Str. Suis: meningitis, deafness, vertigo, arthritis, endocarditis 

Str. Pneumoniae: respiratory 

Str. pyogenes