Clinical/Postmortem case report A case of Streptococcus pluranimalium infection in

a 4-month-old broiler

Dr Solomon Bhandi1

1 Veterinary Services, Western Cape Department of Agriculture: Western Cape, Private Bag x1, Elsenburg 7607

Abstract

Streptococcus pluranimalium is an unusual Streptococcus species that infects both humans and animals. It is still characterised as an emerging bacterium. Therefore, there is little information regarding its pathogenicity and it is known to be a fastidious bacterium to culture.

Case presentation

A 4-month-old broiler was presented at the Cape Exotic Animal Hospital during November 2021 for treatment. The broiler was extremely obtunded and weak. The abdomen was severely distended, and a needle aspiration was done and seromucoid fluid aspirated. Thoracic survey radiography was performed on the bird and radiodense areas were seen in the lungs. The bird unfortunately succumbed to the ailment and was send to the Western Cape Provincial Veterinary Laboratory at the Department of Agriculture for postmortem examination and to rule out diseases like egg-yolk peritonitis, avian leukosis and avian influenza.

Postmortem findings

There were no remarkable antemortem findings seen except massive abdominal distension. The postmortem findings included severe abdominal distension and strawcoloured fluid with jelly-like material seen. There was severe hepatosplenomegaly with rough, whitish Glisson’s capsule. The lungs were severely consolidated and covered by a necrotic cushion. The kidneys were markedly swollen and pale whilst the thymus was prominent. Severe haemorrhage was seen covering the entire gastrointestinal tract, mainly the mucosa. Lesions associated with valvular endocarditis and peritonitis were noticed.

Swabs were taken for bacteriological analysis and molecular investigation. Tissue and organs were taken for histological analysis. The swabs sent to the polymerase chain reaction section came back negative for avian influenza and Newcastle disease viruses, whilst samples sent to bacteriology resulted in a diagnosis of heavy growth of Streptococcus pluranimalium. On histological examination, the liver and kidneys had complete loss of architecture and the parenchyma was necrotised and a severe lymphoplasmacytic infiltration was evident. Bacterial colonies were seen in various organs. A final diagnosis of Streptococcus pluranimalium was reached.

Brief literature on

S. pluranimalium causes a range of disease syndromes ranging from septicaemia, peritonitis, endocarditis and salpingitis in chickens. The clinical signs vary from anorexia, diarrhoea, neurological signs and mortalities. In humans it can cause acute purulent pericoronitis and brain abscesses.

The antibiotics of choice for the treatment of S. pluranimalium are cephalosporins, aminoglycosides, amoxicillin and erythromycin. Where possible, bacterial culture and sensitivity analysis should be performed before treatment can commence. If birds are dying and S. pluranimalium is suspected, the first-choice drugs can be administered while awaiting results of culture and sensitivity analysis. AP

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