Table 2.

Summary of several months of observation and testing that identified a strong association with NBSGW strain and exposure to irradiated diet

Breeding status/strain	Irradiated diet	Autoclaved diet
Breeding
NBSGW	Positive for C. cuniculi (incidence >40%) with LS on 3 separate occasions of starting a breeding colony within a 3-y period	Not done
NSG	Negative for C. cuniculi based on culture and PCR, and absence of LS during the last 5 y in a breeding colony of over 2,500 mice at steady state	Not done
Nonbreeding study rooms
NBSGW	Positive for C. cuniculi by clinical signs, culture, or PCR within 12 to 16 wk postweaning or arrival from vendor on 2 separate studies	Negative for C. cuniculi by culture and PCR and free of LS on 3 separate 16-wk studies
NSG	Negative for C. cuniculi based on culture and PCR and free of LS on several studies where NSG strain was not cohoused with NSG-SGM3 exposed to NBSGW	No data available