Relationship between desiccation tolerance and biofilm formation in Shiga toxin-producing Escherichia coli

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dc.contributor.authorJaved, Muhammad Qasim
dc.contributor.authorUniversity of Lethbridge. Faculty of Arts and Science
dc.contributor.supervisorStanford, Kim
dc.contributor.supervisorKovalchuk, Igor
dc.date.accessioned2024-08-07T19:53:29Z
dc.date.available2024-08-07T19:53:29Z
dc.date.issued2024
dc.degree.levelMasters
dc.description.abstractShiga toxin-producing Escherichia coli (STEC) is a major concern in the food industry and requires effective control measures to prevent foodborne illnesses. Previous studies have demonstrated increased difficulty in the control of biofilm-forming STEC. Desiccation, achieved through osmotic stress and water removal, has emerged as a potential antimicrobial hurdle. This study focused on 254 genetically diverse E. coli strains collected from cattle, carcass hides, hide-off carcasses, and processing equipment. Of these, 141 (55.5%) were STEC and 113 (44.4%) were generic E. coli. The biofilm-forming capabilities of these isolates were assessed, and their desiccation tolerance was investigated to understand the relationships between growth temperature, relative humidity (RH), and bacterial survival. Only 28% of the STEC isolates had the ability to form biofilms, compared to 60% of generic E. coli. Stainless steel surfaces were exposed to different combinations of temperature (0°C or 35°C) and RH (75% or 100%), and survival rates were measured over 72 h and compared to controls. The results revealed that all the strains exposed to 75% RH at any temperature had reduced growth (p < 0.001). In contrast, 35°C and 100% RH supported bacterial proliferation, except for isolates forming the strongest biofilms. The ability of E. coli to form a biofilm did not impact growth reduction at 75% RH. Therefore, desiccation to 75% RH at temperatures of 0°C or 35°C holds promise as a novel antimicrobial hurdle for the removal of biofilm-forming E. coli from challenging-to-clean surfaces and equipment within food processing facilities.
dc.description.sponsorshipBeef Cattle Research Council, Grant # FOS.01.17 Results-Driven Agricultural Research, Grant # 2021R014R
dc.embargoNo
dc.identifier.urihttps://hdl.handle.net/10133/6842
dc.language.isoen
dc.publisherLethbridge, Alta. : University of Lethbridge, Dept. of Biological Sciences
dc.publisher.departmentDepartment of Biological Sciences
dc.publisher.facultyArts and Science
dc.relation.ispartofseriesThesis (University of Lethbridge. Faculty of Arts and Science)
dc.subjectdesiccation tolerance
dc.subjectbiofilm formation
dc.subjectShiga toxin-producing E. coli
dc.subjectfoodborne illnesses
dc.subjectfood processing facilities
dc.subject.lcshDissertations, Academic
dc.subject.lcshEscherichia coli--Research
dc.subject.lcshBiofilms--Prevention--Research
dc.subject.lcshVerocytotoxins--Research
dc.subject.lcshFood--Safety measures--Research
dc.subject.lcshFoodborne diseases--Prevention--Research
dc.subject.lcshFood contamination--Prevention--Research
dc.subject.lcshAnti-infective agents--Research
dc.subject.lcshEscherichia coli infections--Prevention--Research
dc.titleRelationship between desiccation tolerance and biofilm formation in Shiga toxin-producing Escherichia coli
dc.typeThesis
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