Ocaña de Jesús Rosa L, Gutiérrez Ibáñez Ana T, Sánchez Pale Jesús R, Mariezcurrena Berasain María D, Eslava Campos Carlos A, Laguna Cerda Antonio
Facultad de Ciencias Agrícolas, Universidad Autónoma del Estado de México, Toluca, México.
Facultad de Ciencias Agrícolas, Universidad Autónoma del Estado de México, Toluca, México.
Rev Argent Microbiol. 2018 Oct-Dec;50(4):408-416. doi: 10.1016/j.ram.2017.12.001. Epub 2018 Apr 27.
The presence of pathogenic bacteria, such as Escherichia coli affects the quality and safety of vegetables that are consumed fresh and is associated with serious health problems. The objective of this study was to determine if three different strains of E. coli can penetrate and remain in plants and tomato fruits. A completely randomized experimental design was followed for which a tomato crop ("Cid" variety) was established under greenhouse conditions and three treatments were evaluated, T1 (E. coli O157:H7), T2 (E. coli from tomato cultivation [EcT] O157:H16), T3 (E. coli from spinach cultivation [EcH] O105ab) and a T4 control, with 100 plants each and four forms of inoculation: in the substrate, steam, petiole and the peduncle. Samples were carried out in vegetative stage, flowering, fruiting and physiological maturity to quantify in petri dish CFU/g and know if the bacteria managed to move around and recover in root, stem, flower and fruit. The phylogenetic groups that corresponded to the bacteria recovered were confirmed by biochemical tests, serotyping and PCR. At 120 days the recovery of bacteria in the plant was 23% (E. coli O157:H7), 28% (EcT O157:H16) and 55% (EcH O105ab) whit inoculation to the substrate while the inoculation by puncture the recovery was (in the same order) of 5%, 3%, and 4% at 30 days; 37%, 35% and 30% at 90 days; and 42%, 39% and 13% at 65 days. The strains submit the ability to enter the tomato plant and to stay in it and transported to the fruit, without producing that indicate their presence.
致病性细菌（如大肠杆菌）的存在会影响新鲜食用蔬菜的质量和安全性，并与严重的健康问题相关。本研究的目的是确定三种不同菌株的大肠杆菌是否能穿透并留存于植物和番茄果实中。采用完全随机试验设计，在温室条件下种植番茄作物（“Cid”品种），评估三种处理，T1（大肠杆菌O157:H7）、T2（来自番茄种植的大肠杆菌[EcT] O157:H16）、T3（来自菠菜种植的大肠杆菌[EcH] O105ab）以及T4对照，每种处理各100株植物，并采用四种接种方式：在基质中、通过蒸汽、叶柄和果梗接种。在营养期、花期、结果期和生理成熟期采集样本，以在培养皿中定量每克菌落形成单位（CFU/g），并了解细菌是否能在根、茎、花和果实中移动并存活。通过生化试验、血清分型和聚合酶链反应（PCR）确认回收细菌对应的系统发育群。在第120天时，通过基质接种的植物中细菌回收率分别为23%（大肠杆菌O157:H7）、28%（EcT O157:H16）和55%（EcH O105ab），而穿刺接种时，在第30天回收率（按相同顺序）分别为5%、3%和4%；在第90天分别为37%、35%和30%；在第65天分别为42%、39%和13%。这些菌株具有进入番茄植株并留存其中，以及运输到果实中的能力，但不会产生表明其存在的迹象。
