Salmonella Newport in soils amended with heat-treated poultry pellets survived longer and more readily transferred to and persisted on spinach.

Salmonella Newport in soils amended with heat-treated poultry pellets survived longer and more readily transferred to and persisted on spinach. Appl Environ Microbiol. 2019 Mar 15;: Authors: Shah MK, Bradshaw R, Nyarko E, Handy ET, East C, Millner PD, Bergholz TM, Sharma M Abstract Untreated biological soil amendments of animal origin (BSAAO) are commonly used as biological fertilizers, but can harbor foodborne pathogens like Salmonella enterica leading to potential transfer from soils to fruits and vegetables intended for human consumption. Heat-treated poultry pellets (HTPP) can provide produce growers a slow release fertilizer with minimized risk of pathogen contamination. Little is known about the impact of HTTP-amended soil on survival of Salmonella enterica The contributions of RpoS and formation of viable but non-culturable cells to Salmonella survival in soils are also inadaquately understood. We quantified survival of S Newport wild-type (WT) and rpoS-deficient (ΔrpoS) strains in HTPP-amended and unamended soil with or without spinach plants over 91 days using culture and quantitative PCR methods with propidium monoazide (PMA-qPCR). Simulated 'splash' transfer of S. Newport from soil to spinach was evaluated at 35 and 63 days post-inoculation (dpi). S. Newport WT and ΔrpoS reached the limit of detection - 1.0 log CFU/gdw (gram dry weight) - in unamended soil after 35 days, whereas 2-4 log CFU/gdw was observed for both WT a...
Source: Applied and Environmental Microbiology - Category: Microbiology Authors: Tags: Appl Environ Microbiol Source Type: research