Dev Kumar Govindaraj, Williams Robert C, Sriranganathan Nammalwar, Boyer Renee R, Eifert Joseph D
1 Department of Food Science and Technology, Virginia Tech , Blacksburg, Virginia.
2 Center for Molecular Medicine and Infectious Diseases , Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech, Blacksburg, Virginia.
Foodborne Pathog Dis. 2018 Sep;15(9):548-553. doi: 10.1089/fpd.2017.2416. Epub 2018 Jul 16.
Salmonella serotypes linked to tomato-associated outbreaks were evaluated for survival in soil and water over a 40-day period. Salmonella enterica serotypes Anatum, Baildon, Braenderup, Montevideo, Newport, and Javiana were inoculated separately into sterile soil and water, followed by plating onto TSAYE and XLT4 at 10-day intervals. Biofilm production by Salmonella serotypes was measured on both quartz particles (soil surrogate) and glass coverslips, and was evaluated using a crystal violet dye assay. Salmonella populations in soil and water over 40 days indicated no significant differences between Salmonella serotypes tested (p > 0.05). Over a 40-day period, there was a 1.84 ± 0.22 log CFU/g and 1.56 ± 0.54 CFU/mL decrease in populations of Salmonella in soil and water, respectively. Enumeration indicated that Salmonella population fluctuated in water but decreased linearly in soil. All serotypes tested produced the "red dry and rough" morphotype on Congo Red agar. Biofilm produced by all the Salmonella serotypes tested was significantly different on quartz particles than on glass coverslips (p < 0.0001), indicating that material and surface characteristics could affect biofilm development. The ability of Salmonella serotypes to persist in soil or water and attach to abiotic surfaces through biofilm formation affirms that contact surfaces, soil, water, and sediment should be considered as possible sources of cross-contamination in the farm environment.
对与番茄相关疫情爆发有关的沙门氏菌血清型在土壤和水中40天内的存活情况进行了评估。肠炎沙门氏菌血清型阿纳姆、贝尔登、布伦德鲁普、蒙得维的亚、纽波特和哈维亚纳分别接种到无菌土壤和水中，然后每隔10天接种到TSAYE和XLT4培养基上进行平板培养。在石英颗粒（土壤替代物）和玻璃盖玻片上测量沙门氏菌血清型的生物膜形成情况，并使用结晶紫染色法进行评估。40天内土壤和水中的沙门氏菌数量表明，所测试的沙门氏菌血清型之间没有显著差异（p>0.05）。在40天的时间里，土壤和水中沙门氏菌数量分别下降了1.84±0.22 log CFU/g和1.56±0.54 CFU/mL。计数表明，沙门氏菌数量在水中波动，但在土壤中呈线性下降。所有测试血清型在刚果红琼脂上均产生“红色干燥粗糙”形态型。所有测试的沙门氏菌血清型在石英颗粒上产生的生物膜与在玻璃盖玻片上产生的生物膜有显著差异（p<0.0001），表明材料和表面特性可能影响生物膜的形成。沙门氏菌血清型在土壤或水中持续存在并通过生物膜形成附着在非生物表面的能力证实，在农场环境中，接触表面、土壤、水和沉积物应被视为可能的交叉污染来源。
