A rosin-functionalized plastic surface inactivates African swine fever virus

Abstract

African swine fever virus (ASFV) causes a severe hemorrhagic disease in pigs, leading to up to 100% case fatality. The virus May persist on solid surfaces for long periods; thus, fomites, such as contaminated clothing, footwear, farming tools, equipment, and transport vehicles, May contribute to the indirect transmission of the virus. Here, a plastic surface functionalized with tall oil rosin was tested against ASFV. The rosin-functionalized plastic reduced ASFV infectious virus titers by 1.3 log₁₀ after 60 min of contact time and killed all detectable viruses after 120 min, leading to a ~ 6 log₁₀ reduction. In contrast, the infectious virus titer of ASFV in contact with low-density polyethylene (LDPE) plastic reduced <1 log₁₀ after 120 min. Transmission electron microscopy (TEM) showed significant morphological changes in the virus after 2 h of contact with the rosin-functionalized plastic surface, but no changes were observed with the LDPE plastic. The use of antiviral plastic in the farming sector could reduce the spread of ASFV through fomites and could thus be part of an integrated program to control ASFV.

Keywords: ASFV; African swine fever; antiviral surface; plastic; rosin.

Figure 1

ASFV titers after contact with rosin-functionalized (PREXELENT^®) or LDPE plastic as determined using qPCR (A) or HAD₅₀ assay (B). ASFV at x10⁶ HAD₅₀ was incubated with rosin-functionalized plastic (PREXELENT^®) (red triangles) or LDPE plastic (black squares) for 5, 10, 30, 60, 120, 240, or 480 min and flushed with RPMI. ASFV genome copies from the flush were determined by qPCR (A) and viable virus titers by HAD₅₀ assay (B). Statistical significance was determined using t-tests for each time point, adjusted for multiple tests (**p < 0.01, *** p < 0.001).

Figure 2

ASFV as visualized by TEM incubated with rosin-functionalized plastic (PREXELENT^®) (A) or LDPE plastic (B). Viruses were gently pelleted down from fixative solution and subjected to negative staining (see Material and Methods section). Bar, 100 nm.