The effects of environmental conditions on persistence and inactivation of Brucella suis on building material surfaces.

Aims: The purpose of this study was to evaluate the effects of environmental conditions and material type on persistence and inactivation of Brucella suis.

Methods And Results: Brucella suis (approx. 1 × 10(8) CFU) was spiked onto surfaces (glass, aluminium and wood) by liquid inoculation. Persistence was evaluated over 56 days at 22 ± 2°C, 40 ± 15% r.h. and 5 ± 3°C, 30 ± 15% r.h. In addition, three readily available decontaminants (pH-adjusted bleach, 70% ethanol and 1% citric acid) were evaluated for their effectiveness at inactivating Br. suis on these materials. Decontaminations were conducted following 0 and 28 days exposure to the two conditions. Results indicated that Br. suis can persist on environmental surfaces for at least 56 days. Persistence was highest at low temperature. Decontamination was most challenging on wood with all three decontaminants.

Conclusions: Following a Br. suis contamination incident, passive decontamination (through attenuation) may not be feasible, as this organism can persist for months. In addition, the results suggest that some sporicidal decontaminants may be ineffective on materials such as wood, even for vegetative biological agents such as Br. suis.

Significance And Impact Of Study: This study aids incident commanders and remediation experts to make informed decisions regarding decontamination after a biological contamination incident.