Bhaduri Saumya, Sheen Shiowshuh, Sommers Christopher H
Molecular Characterization of Foodborne Pathogens Research Unit, U. S. Dept. of Agriculture, Agricultural Research Service, Eastern Regional Research Center, Wyndmoor, PA, 19038, USA.
J Food Sci. 2014 May;79(5):M911-6. doi: 10.1111/1750-3841.12413. Epub 2014 Apr 24.
Virulence of many foodborne pathogens is directly linked to genes carried on self-replicating extra-chromosomal elements, which can transfer genetic material, both vertically and horizontally, between bacteria of the same and different species. Pathogenic Yersinia enterocolitica harbors a 70-kb virulence plasmid (pYV) that encodes genes for low calcium response, crystal violet (CV) binding, Congo red uptake, autoagglutination (AA), hydrophobicity (HP), type III secretion channels, host immune suppression factors, and biofilm formation. Ionizing radiation and modified atmosphere packaging (MAP) are used to control foodborne pathogens and meat spoilage. In this study, the effect of gamma radiation and modified atmosphere (air, 100% N2 , 75% N2 : 25% CO2 , 50% N2 : 50% CO2 , 25% N2 : 75% CO2 , 100% CO2 ) were examined by using the CV binding phenotype, for the presence or absence of pYV in Y. enterocolitica, suspended in raw ground pork. All Y. enterocolitica serovars used (O:3, O:8, and O5,27) were more sensitive to radiation as the CO2 concentration increased above 50%. Crystal violet binding following a radiation dose of 1.0 kGy, which reduced the Y. enterocolitica serovars >5 log, was greatest in the presence of air (ca. 8%), but was not affected by N2 or CO2 concentration (ca. 5%). Following release from modified atmosphere after irradiation, the loss of CV binding rose from 5% to 8% immediately following irradiation to >30% after outgrowth at 25 °C for 24 h. These results, using Y. enterocolitica as a model system, indicate that the risk of foodborne illness could be affected by the loss of virulence factors when postprocess intervention technologies are used.
Provides gamma radiation D10 data for inactivation data for Y. enterocolitica irradiated under modified atmosphere and information to risk assessors regarding the difference between pathogen presence versus actual virulence.
许多食源性病原体的毒力与自我复制的染色体外元件所携带的基因直接相关，这些元件可在同种和不同种细菌之间垂直和水平转移遗传物质。致病性小肠结肠炎耶尔森菌携带一个70kb的毒力质粒（pYV），该质粒编码低钙反应、结晶紫（CV）结合、刚果红摄取、自凝（AA）、疏水性（HP）、III型分泌通道、宿主免疫抑制因子和生物膜形成等基因。电离辐射和气调包装（MAP）用于控制食源性病原体和肉类腐败。在本研究中，通过使用CV结合表型，检测了γ辐射和气调（空气、100%N2、75%N2:25%CO2、50%N2:50%CO2、25%N2:75%CO2、100%CO2）对悬浮在生碎猪肉中的小肠结肠炎耶尔森菌中pYV存在与否的影响。随着CO2浓度增加到50%以上，所有使用的小肠结肠炎耶尔森菌血清型（O:3、O:8和O5,27）对辐射更敏感。1.0kGy辐射剂量后结晶紫结合情况，该剂量使小肠结肠炎耶尔森菌血清型减少>5个对数，在空气中（约8%）最大，但不受N2或CO2浓度（约5%）影响。辐照后从气调环境中释放后，CV结合丧失率从辐照后立即的5%上升到25℃生长24小时后的>30%。这些以小肠结肠炎耶尔森菌为模型系统的结果表明，使用后处理干预技术时，食源性疾病风险可能会受到毒力因子丧失的影响。
提供气调环境下辐照的小肠结肠炎耶尔森菌失活数据的γ辐射D10数据，以及向风险评估人员提供有关病原体存在与实际毒力差异的信息。
Zotero 插件