東華大學圖書館 |

Language: English

Help

回圖書館首頁

手機版館藏查詢

Back

Switch To: Labeled | MARC Mode | ISBD

The role of molecular methods in the...

Stevens, Kelly A.

Linked to FindBook

Google Book

Amazon

博客來

The role of molecular methods in the detection of pathogens in food.

Record Type:	Electronic resources : Monograph/item
Title/Author:	The role of molecular methods in the detection of pathogens in food./
Author:	Stevens, Kelly A.
Description:	157 p.
Notes:	Source: Dissertation Abstracts International, Volume: 65-01, Section: B, page: 0011.
Contained By:	Dissertation Abstracts International65-01B.
Subject:	Agriculture, Food Science and Technology. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3120260

The role of molecular methods in the detection of pathogens in food.
Stevens, Kelly A.

The role of molecular methods in the detection of pathogens in food. - 157 p.

Source: Dissertation Abstracts International, Volume: 65-01, Section: B, page: 0011.

Thesis (Ph.D.)--North Carolina State University, 2004.

The research described here addresses several issues associated with testing food samples for the presence of pathogens. In the first study, we developed and evaluated a combined concentration/molecular detection method for the direct detection of foodborne pathogens (Listeria monocytogenes and Salmonella enterica serovar enteritidis) directly from complex dairy matrices, bypassing the need for cultural enrichment. PCR detection limits of 103 and 101 CFU per 11 g sample were achieved for L. monocytogenes and serovar. Enteritidis, respectively, in mild cheddar cheese and non-fat yogurt without prior cultural enrichment. In a related study, commercially available proprietary kits (MICROB EnrichRTM and MICROBExpress RTM) for nucleic acid purification were evaluated to improve the direct detection of Listeria monocytogenes from a frankfurter matrix. PCR detection limits were 105 CFU/11g sample and RT-PCR detection limits were 103 CFU/11g. Detection limits were improved an additional 10-fold (to 102 CFU/11g) when extracted RNA was further purified using MICROBExpressRTM. In this study, amplification via RT-PCR yielded more sensitive detection that DNA based amplification and further purification of RNA extracts was beneficial for improving RT-PCR detection limits. Direct detection of pathogens from food matrices was achieved without cultural enrichment with detection limits approaching those of other "rapid" methods. Sample manipulations during sample preparation, nucleic acid extraction and amplification steps may aide in achieving desired detection limits. In the second study, automated ribotyping using the RiboPrinterRTM microbial characterization unit was evaluated for its ability to differentiate thirty-nine isolates of multi-drug resistant Salmonella enterica serovar Typhimurium. The strains could not be differentiated from one another using ribotyping, suggesting that in this case, phenotypic methods may be more discriminatory. Ribotyping data may best be used in conjunction with phenotypic and serological testing results in order to adequately differentiate isolates. In the final study, a formal decision analysis model was designed for a food-borne pathogen testing decision from a food processor's perspective. In general, the model indicated that testing for highly prevalent pathogens may provide an improvement in food safety but end product testing for pathogens of low prevalence should be carefully considered and may not be justified due to limited return on investment.Subjects--Topical Terms:

1017813
Agriculture, Food Science and Technology.

The role of molecular methods in the detection of pathogens in food.
LDR:03400nmm 2200277 4500 001 1861454
005 20041111121801.5
008 130614s2004 eng d
035 $a (UnM)AAI3120260
035 $a AAI3120260
040 $a UnM $c UnM
100 1 $a Stevens, Kelly A. $3 1949054
245 1 4 $a The role of molecular methods in the detection of pathogens in food.
300 $a 157 p.
500 $a Source: Dissertation Abstracts International, Volume: 65-01, Section: B, page: 0011.
500 $a Director: Lee-Ann Jaykus.
502 $a Thesis (Ph.D.)--North Carolina State University, 2004.
520 $a The research described here addresses several issues associated with testing food samples for the presence of pathogens. In the first study, we developed and evaluated a combined concentration/molecular detection method for the direct detection of foodborne pathogens (Listeria monocytogenes and Salmonella enterica serovar enteritidis) directly from complex dairy matrices, bypassing the need for cultural enrichment. PCR detection limits of 103 and 101 CFU per 11 g sample were achieved for L. monocytogenes and serovar. Enteritidis, respectively, in mild cheddar cheese and non-fat yogurt without prior cultural enrichment. In a related study, commercially available proprietary kits (MICROB EnrichRTM and MICROBExpress RTM) for nucleic acid purification were evaluated to improve the direct detection of Listeria monocytogenes from a frankfurter matrix. PCR detection limits were 105 CFU/11g sample and RT-PCR detection limits were 103 CFU/11g. Detection limits were improved an additional 10-fold (to 102 CFU/11g) when extracted RNA was further purified using MICROBExpressRTM. In this study, amplification via RT-PCR yielded more sensitive detection that DNA based amplification and further purification of RNA extracts was beneficial for improving RT-PCR detection limits. Direct detection of pathogens from food matrices was achieved without cultural enrichment with detection limits approaching those of other "rapid" methods. Sample manipulations during sample preparation, nucleic acid extraction and amplification steps may aide in achieving desired detection limits. In the second study, automated ribotyping using the RiboPrinterRTM microbial characterization unit was evaluated for its ability to differentiate thirty-nine isolates of multi-drug resistant Salmonella enterica serovar Typhimurium. The strains could not be differentiated from one another using ribotyping, suggesting that in this case, phenotypic methods may be more discriminatory. Ribotyping data may best be used in conjunction with phenotypic and serological testing results in order to adequately differentiate isolates. In the final study, a formal decision analysis model was designed for a food-borne pathogen testing decision from a food processor's perspective. In general, the model indicated that testing for highly prevalent pathogens may provide an improvement in food safety but end product testing for pathogens of low prevalence should be carefully considered and may not be justified due to limited return on investment.
590 $a School code: 0155.
650 4 $a Agriculture, Food Science and Technology. $3 1017813
650 4 $a Biology, Microbiology. $3 1017734
650 4 $a Health Sciences, Pathology. $3 1017854
690 $a 0359
690 $a 0410
690 $a 0571
710 2 0 $a North Carolina State University. $3 1018772
773 0 $t Dissertation Abstracts International $g 65-01B.
790 1 0 $a Jaykus, Lee-Ann, $e advisor
790 $a 0155
791 $a Ph.D.
792 $a 2004
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3120260