Beta-Haemolytic Streptococcus (BHS)

Prevalence
Variable: None in isolator-reared colonies to common in some barrier colonies.
 
Diagnosis
Isolation by microbiological culture from healthy mice or rats is no cause for alarm.
 
Disease
No reports in mice and rats. Occasional outbreaks have been reported but are usually associated with severely immunocompromised animals with experimental manipulation. They are considered opportunists in mice and rats. 
 
Screening
Microbial screening.
 
Transmission
Direct contact with ill or carrier animals. Zoonotic, with possible human to animal.
 
Duration
Variable.
 
Significance
No evidence of interference of research in mice and rats with carrier status. However, immunocompromised animals may develop suppurative disease and therefore be removed from programmes prematurely.
 
Control
Bioexclusion housing, HEPA filters and normal animal facility standard operating procedures should prevent transmission of BHS between humans and animals, and between animals and animals. Rederivation by embryo transfer or hysterectomy onto BHS-free mothers. 
 
Reading
  • The Mouse in Biomedical research, Vol. 2: Diseases Fox and Barthold. Second Edn. Elsevier, Inc. 2007.
  • What happened to the Streptococci: Overview of Taxonomic and Nomenclature Changes, Facklam R., Clinical microbiology Reviews, Oct. 2002 15(4):613-630.