Aerosolization of Mycoplasma synoviae compared with Mycoplasma gallisepticum and Enterococcus faecalis

Abstract

In order to study the airborne transmission of an arthropathic strain of Mycoplasma synoviae, preliminary aerosol experiments were performed. They were conducted in duplicate in an empty isolator (1.3 m3) to assess the yield and viability of M. synoviae with time compared with Mycoplasma gallisepticum and Enterococcus faecalis. After aerosol generation air samples were taken with two different devices using gelatine or cellulose nitrate filters. There was no difference between the devices, but cellulose nitrate filters yielded very low bacterial counts. The aerosolized dose per isolator for M. synoviae was 3.4 × 1010 colony-forming units (cfu), for M. gallisepticum was 2.6 × 1010 cfu and for E. faecalis was 3 × 1010 cfu. Immediately after aerosolization, concentrations of about 106 to 107 cfu/m3, 107 to 108 cfu/m3 and 108 to 109 cfu/m 3 air of M. synoviae, M. gallisepticum and E. faecalis were found, respectively. At 25 min M. synoviae concentrations dropped below the detection level (< 4 × 104 cfu), while 105 to 10 6 and 108 to 109 cfu were found for M. gallisepticum and E. faecalis, respectively. The average M. synoviae concentration during the experiment was estimated at 102 to 10 3 cfu/l. The M. gallisepticum and E. faecalis aerosol generated an average of approximately 103 to 104 cfu/l air and 10 5 to 106 cfu/l air, respectively. Thus mycoplasma and E. faecalis aerosols were successfully generated despite considerable initial loss as measured by culture. The loss was greater in the mycoplasma aerosols, especially those of M. synoviae.