Aerosolization of Newcastle disease vaccine virus and Enterococcus faecalis

In order to study the aerosol transmission of arthropathic and amyloidogeni c Enterococcus faecalis strains, preliminary aerosol experiments were perfo rmed. The experiments were carried out in empty isolators to assess the yie ld and viability of E. faecalis and Newcastle disease vaccine virus (NDVV) aerosol particles with time. NDVV was aerosolized because this virus would be used in combination with E faecalis in a subsequent study. Concentration s of about 10(5) colony-forming units (CFU) of E. faecalis/m(3) of air were still found 30 min after the aerosol application. At 45 min, however, E. f aecalis concentrations dropped below the detection level. The average E fae calis concentration during the aerosol experiment was estimated at 10(5) CF U/liter. The NDVV aerosol generated an average of 10(4)-10(5) 50% embryo in fective dose per liter of air. In these experiments, E. faecalis and NDVV a erosols were successfully generated despite considerable initial particle l oss. The bacteria and virus uptakes per chick are discussed in case day-old chicks would be exposed to these aerosols.