IDENTIFICATION OF A PARATYPHOID-ENTERITIDIS STRAIN ASSOCIATED WITH EPIZOOTICS OF MOUSE TYPHOID

Area of Science:

• Microbiology
• Veterinary Pathology
• Bacterial Pathogenesis

Background:

• Epizootics caused by Bacillus species pose a significant threat to laboratory animal colonies.
• Previous outbreaks in laboratory mice were linked to unidentified Bacillus strains.
• Bacillus festis caviae is known to cause similar affections in guinea pigs.

Purpose of the Study:

• To identify the Bacillus species responsible for recent epizootics in laboratory mice.
• To determine the relationship between the unknown Bacillus strain and known type strains.
• To establish a basis for effective control and prevention strategies.

Main Methods:

• Bacterial isolation and culturing from affected animals.
• Biochemical characterization of cultural reactions.
• Serological testing including direct and cross-agglutination assays.
• Adsorption experiments to assess antigenic similarities.

Main Results:

• The unknown Bacillus isolate was identified as Bacillus festis caviae Smith.
• Bacillus festis caviae produced similar pathological signs in experimentally infected guinea pigs.
• The unknown strain showed close antigenic relationship to the "mutton" aertrycke strain of Schütze.
• Cultural and serological data confirmed the close relationship between the unknown and type strains.

Conclusions:

• Bacillus festis caviae is identified as the causative agent of epizootics in laboratory mice.
• The close antigenic relationship to the "mutton" aertrycke strain provides insights into its pathogenicity.
• This identification is crucial for implementing targeted control measures in research facilities.