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000057092 0247_ $$2doi$$a10.3389/fmicb.2016.01376
000057092 0248_ $$2sideral$$a96639
000057092 037__ $$aART-2016-96639
000057092 041__ $$aeng
000057092 100__ $$aEspina, L.
000057092 245__ $$aDetection of thermal sublethal injury in escherichia coli via the selective medium plating technique: Mechanisms and improvements
000057092 260__ $$c2016
000057092 5060_ $$aAccess copy available to the general public$$fUnrestricted
000057092 5203_ $$aIn food preservation, the synergistic combination of different technologies aims to maximize the total lethality of the process and minimize the intensity of each hurdle. This is especially the case when at least one of the treatments can cause sublethal (reparable) injury in a great proportion of the population, so that sublethally injured cells can end up being entirely inactivated by the other hurdle(s). The selective medium plating technique (SMPT) is extensively used to enumerate bacterial sublethal injury after inimical treatments, being sodium chloride added to the recovery medium to detect damaged bacterial envelopes. However, little work has been done to explain the reasons for the inability of sublethally injured cells to outgrow in selective agar media, whereas they are able to grow in non-selective agar. In the present paper, the performance of SMPT on Escherichia coli cells after heat treatments is explored by applying different selective agents in the recovery media, using mutants lacking factors involved in osmoregulation, and also by examining the integrity of the cytoplasmic membrane. In view of the results, the possibility of a specific toxic effect of Na+ as the main mechanism under SMPT was discarded, since the same level of sublethal injury was detected using KCl instead of NaCl. The synthesis of the osmoprotectant trehalose determined the maximum osmotolerance of intact cells to the selective agents, but was not crucial in the quantification of sublethal injury. Moreover, for the first time, the extent of sublethal injury detected via SMPT was directly correlated with the physical loss of integrity of the cell membrane in 99.999% of the initial population. This was achieved through statistical analysis of flow cytometry data using propidium iodide-exclusion technique when that dye was added before thermal treatments. The present work confirms the adequacy of SMPT as a tool for detecting the occurrence and quantity of sublethally injured cells after thermal treatments and thus, for efficiently designing the combination of heat with other preservation techniques. We also propose the study of statistical analysis from flow cytometry data for a more rapid quantification of bacterial sublethal injury in a broad detection range.
000057092 536__ $$9info:eu-repo/grantAgreement/ES/MINECO/AGL2015-69565-P$$9info:eu-repo/grantAgreement/ES/MINECO/AGL2012-32165
000057092 540__ $$9info:eu-repo/semantics/openAccess$$aby$$uhttp://creativecommons.org/licenses/by/3.0/es/
000057092 590__ $$a4.076$$b2016
000057092 591__ $$aMICROBIOLOGY$$b25 / 124 = 0.202$$c2016$$dQ1$$eT1
000057092 592__ $$a1.758$$b2016
000057092 593__ $$aMicrobiology (medical)$$c2016$$dQ1
000057092 593__ $$aMicrobiology$$c2016$$dQ1
000057092 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion
000057092 700__ $$0(orcid)0000-0002-7629-8101$$aGarcía-Gonzalo, D.$$uUniversidad de Zaragoza
000057092 700__ $$0(orcid)0000-0002-0238-6328$$aPagán, R.$$uUniversidad de Zaragoza
000057092 7102_ $$12008$$2780$$aUniversidad de Zaragoza$$bDpto. Produc.Animal Cienc.Ali.$$cÁrea Tecnología de Alimentos
000057092 773__ $$g7 (2016), 1376 [12 pp.]$$pFront. microbiol.$$tFRONTIERS IN MICROBIOLOGY$$x1664-302X
000057092 8564_ $$s1101420$$uhttps://zaguan.unizar.es/record/57092/files/texto_completo.pdf$$yVersión publicada
000057092 8564_ $$s99513$$uhttps://zaguan.unizar.es/record/57092/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada
000057092 909CO $$ooai:zaguan.unizar.es:57092$$particulos$$pdriver
000057092 951__ $$a2020-04-28-12:01:00
000057092 980__ $$aARTICLE