Needle disinfection and bioptic wood sampling achieved with a disposable for drill resistance measurement devices

Needle drill resistance measurement devices (NDRMDs) are often used during tree hazard assessment campaigns to detect and measure the extent of wood decay and other defects of wood in trees, despite of the possibility of transmission of potentially pathogenic microbial inoculum from tree to tree through unclean needles. Here, we describe a disposable connectable to NDRMDs through an adapter and we report on its efficacy not only at disinfecting the needle, thus reducing the likelihood of disease transmission, but also at collecting wood samples for bioptic purposes, whose subsequent analysis may be pivotal for, or allow to refine, the prognosis. The complete efficacy of the disposable at disinfecting the needle was determined through three different experiments conducted under controlled conditions in vitro and in vivo using both wood decay fungi and the canker stain pathogen of plane trees, and under field conditions. The disposable combined with NDRMD proved to be as effective as state-of-the-art drilling methods at collecting wood samples for subsequent PCR-based molecular diagnosis of wood decay fungi (Fisher's exact test for count data; P = 4.846 × 10−7) as determined through comparative sampling and diagnostic assays on 42 trees. The disposable allows not only for a routinely, complete and fully standardized disinfection of the needle, but also provides the opportunity to automatically and efficiently collect bioptic wood samples for subsequent phytopathological analyses.