One-day-old brown layer chicks were exposed to an
aerosol of an arthropathic and amyloidogenic Enterococcus faecalis strain alone or after being subjected to treatment with
formaldehyde gas (100-200 ppm). Four-day-old chicks were also treated with the same
aerosol but
after treatment with a
Newcastle disease vaccine virus (NDVV)
aerosol or
intramuscular injection with methylprednisolon at day 1. The same E. faecalis strain was inoculated intramuscularly in day-old chicks as positive control.
Bacteremia with time showed that 24 hr after the
aerosol the day-old exposed chicks had the highest rate of positive blood cultures (70%-80%). Lower numbers of bacteremic birds at this point in time were found in the chicks treated with E. faecalis
aerosol at day 4 (3/10 in the methylprednisolon-treated group and 0/10 in the NDVV-treated group) and the E. faecalis intramuscular-injected group at day 1 (2/10).
Formaldehyde gas treatment did not favor the occurrence of
bacteremia. NDVV
aerosol exposure or injection with
corticosteroids did not favor the occurrence of
bacteremia 24 hr after E. faecalis
aerosol exposure at day 4 either, although 66 days after
aerosol, one bird (1/14) treated with NDVV showed
bacteremia. A few bacteremic birds were found 10 days after
aerosol in the NDVV- and methylprednisolon-treated groups, whereas at 14 days after
aerosol, one bacteremic bird was seen in the group subjected to E. faecalis
aerosol at day 1, indicating the occurrence of chronic
bacteremia. In contrast to the E. faecalis intramuscular-inoculated birds, no joint pathology was seen in the
aerosol-exposed groups in spite of the occurrence of chronic
bacteremia.