Development of highly specific monoclonal antibodies to Listeria sp. and Listeria monocytogenes

The aim of this study was to develop monoclonal and polyclonal antibodies against Listeria spp., a selective culture broth, and an immunoassay to enable a 21 hour assay to detect Listeria spp. in foodstuffs. Listeria is a common contaminant of food production. Its hardiness and ability to grow under refrigeration make it a significant contaminant of pre-cooked foods and processed dairy products. Listeria monocytogenes is considered the major pathogen and is responsible for the condition listeriosis, a significant public health risk with a high mortality rate. Commercial assays currently in existence are either PCR-based more than 24 hours. A mix of species and serotypes of Listeria grown at 37°C and heat attenuated of was used as an immunogen. Monoclonal antibody producing cell lines were produced by hybridoma fusion. A culture broth was developed simultaneously and was able to suppress growth of endogenous food bacteria while at the same time not significantly slowing the growth of Listeria spp. Polyclonal sheep antibodies were purified using immunogen immobilised onto agarose. In conclusion, the production of specific monoclonal antibodies against attenuated Listeria grown at 37°C was shown to be feasible. Two monoclonal lines were produced. One line was unstable, but detected 9 out of 10 of the Listeria strains. None of the positive cell wells in all screening plates was able to detect all Listeria strains simultaneously. Immunopurification of immunised sheep serum provided highly specific polyclonal antibodies which may be potentially of more interest than monoclonal antibodies for assay development, although high non-specific binding was problematic when used as both capture and detection antibody in a sandwich assay. Overall, the combination of selective broth and antibodies developed in this study were able to detect a very small inoculum (<100 CFU) of Listeria in all foodstuffs tested in a 21 hour assay.

Name dc:type.qualificationname

mphil

Level dc:type.qualificationlevel

masters-pg

Grantor dc:publisher.institution

University of Strathclyde

Year dc:date.issued

2013

Author dc:creator

• Richardson, Kenneth

DOI

10.48730/40j6-xd15

Identifier

T13527

OAI identifier oai:identifier

oai:strathclyde:p8418n267