Identification of microorganisms in food ecosystems and characterization of physical and molecular events involved in biofilm development
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The Ohio State University / OhioLINK
2005
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| Online Access: | http://rave.ohiolink.edu/etdc/view?acc_num=osu1133304823 |
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ndltd-OhioLink-oai-etd.ohiolink.edu-osu11333048232021-08-03T05:50:32Z Identification of microorganisms in food ecosystems and characterization of physical and molecular events involved in biofilm development Luo, Hongliang Real-time PCR detection Alicyclobacillus juice Listeria monocytogenes CluA conjugation biofilm Lactococcus lactis antibiotic resistance food ecosystem <p>Most foods can be considered as ecosystems containing various microorganisms including pathogenic, spoilage, commensal microbes and fermentation starter cultures. Microbial biofilm ecosystems also form on the surfaces of processing equipment. The interactions among microbes and between microbes and various surfaces play an important role in the persistence and the prevalence of these microbes in the food environment. Diversity of food matrices adds complexity to and directly shapes the composition of the microbiota in these ecosystems. Proper identification and quantification of microbes, evaluation of potential risks in the food ecosystems, and characterization of the physical and molecular events involved in ecosystems, including biofilm development, are among the primary tasks for food microbiologists. The objectives of this study are to develop a rapid detection system for foodborne microorganisms using molecular approaches, to characterize component(s) involved in biofilm development, and to examine the contribution of commensal organisms in ecosystem development and horizontal gene transfer.</p><p>A real-time PCR system was developed to rapidly detect <i>Alicyclobacillus</i> spp. and <i>Listeria monocytogenes</i> in food. Detection of less than 10 bacterial cells per reaction was achieved within 4-7 hours. CluA, a surface protein related to cell clumping, was found to be an important component in the development of <i>Lactococcus lactis</i> biofilm. Biofilm attributes can be disseminated within the ecosystem by conjugation, and a lactococcal strain carrying the intrinsic high frequency gene transfer mechanism could increase the transfer of pAMβ1 by 10,000-fold. The study demonstrated, for the first time, that conjugation facilitated biofilm formation in Gram-positive bacteria, and that commensal organisms not only served as a gene pool but also as enhancers facilitating horizontal gene transfer, including the dissemination of the drug resistance genes. Finally, our data showed that commensal organisms, such as <i>Pseudomonas</i> , enhanced mixed-culture biofilm formation involving other microorganisms such as <i>Staphylococcus</i> , suggesting the contribution of commensal organisms in pathogen persistence.</p><p>The rapid detection system developed in this study, has direct applications in both food industry and basic scientific research. Results from this study advanced the knowledge in biofilm development and gene transfer mechanisms.</p> 2005-12-02 English text The Ohio State University / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=osu1133304823 http://rave.ohiolink.edu/etdc/view?acc_num=osu1133304823 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws. |
| collection |
NDLTD |
| language |
English |
| sources |
NDLTD |
| topic |
Real-time PCR detection Alicyclobacillus juice Listeria monocytogenes CluA conjugation biofilm Lactococcus lactis antibiotic resistance food ecosystem |
| spellingShingle |
Real-time PCR detection Alicyclobacillus juice Listeria monocytogenes CluA conjugation biofilm Lactococcus lactis antibiotic resistance food ecosystem Luo, Hongliang Identification of microorganisms in food ecosystems and characterization of physical and molecular events involved in biofilm development |
| author |
Luo, Hongliang |
| author_facet |
Luo, Hongliang |
| author_sort |
Luo, Hongliang |
| title |
Identification of microorganisms in food ecosystems and characterization of physical and molecular events involved in biofilm development |
| title_short |
Identification of microorganisms in food ecosystems and characterization of physical and molecular events involved in biofilm development |
| title_full |
Identification of microorganisms in food ecosystems and characterization of physical and molecular events involved in biofilm development |
| title_fullStr |
Identification of microorganisms in food ecosystems and characterization of physical and molecular events involved in biofilm development |
| title_full_unstemmed |
Identification of microorganisms in food ecosystems and characterization of physical and molecular events involved in biofilm development |
| title_sort |
identification of microorganisms in food ecosystems and characterization of physical and molecular events involved in biofilm development |
| publisher |
The Ohio State University / OhioLINK |
| publishDate |
2005 |
| url |
http://rave.ohiolink.edu/etdc/view?acc_num=osu1133304823 |
| work_keys_str_mv |
AT luohongliang identificationofmicroorganismsinfoodecosystemsandcharacterizationofphysicalandmoleculareventsinvolvedinbiofilmdevelopment |
| _version_ |
1719426403547480064 |