Title

Influence of Strain and Temperature on Growth, Survival and Biofilm Formation by Listeria Monocytogenes and Salmonella Spp. in High and Low Concentrations of Catfish Mucus Extract on Four Food-Contact Surfaces and their Destruction

Issuing Body

Mississippi State University

Advisor

Nannapaneni, Ramakrishna

Committee Member

Schilling, M. Wes

Committee Member

Sharma, Chander Shekhar

Committee Member

Cheng, Wen-Hsing

Date of Degree

1-1-2017

Original embargo terms

Visible to MSU only for 2 years

Document Type

Dissertation - Open Access

Degree Name

Doctor of Philosophy

College

College of Agriculture and Life Sciences

Department

Department of Food Science, Nutrition and Health Promotion

Abstract

According to USDA-FSIS reports, L. monocytogenes and Salmonella are two important foodborne pathogens that are prevalent throughout catfish environment. Channel catfish (Ictalurus punctatus) is the most important aquaculture species in the United States accounting for more than 60% of its aquaculture production. The objectives of this study were to determine the effect of strain, temperature concentration on the growth, survival and biofilm formation of L. monocytogenes and Salmonella using catfish mucus extract on different food-contact surfaces. Growth and survival of L. monocytogenes and Salmonella was greater at the higher concentration of mucus extract at both 10°C and 22°C. In 15 micrograms/ml catfish mucus extract L. monocytogenes and Salmonella counts increased to 4.5 log CFU/ml after 72 h at 10°C and 5-7 log CFU/ml counts after 32-48 h at 22°C. In 375 micrograms/ml catfish mucus extract L. monocytogenes and Salmonella counts increased to 6-7 log CFU/ml counts after 72 h at 10°C and 8-9 log CFU/ml counts after 32-48 h at 22°C. L. monocytogenes and Salmonella were able to grow and survive for more than 63 days with at least 4-6 log CFU/ml at 10°C and 6-8 log CFU/ml in 375 micrograms/ml and 15 micrograms/ml of catfish mucus extract respectively. No differences (P > 0.05) among L. monocytogenes and Salmonella strains were observed to form biofilms in the presence catfish mucus extract on the stainless steel surface. The biofilm formation by L. monocytogenes and Salmonella in catfish mucus extract was less (P < 0.05) on buna-n rubber when compared to stainless steel, polyethylene and polyurethane surfaces. Therefore, the findings in this study show that catfish mucus promotes L. monocytogenes and Salmonella to grow and subsequently form biofilms on different food-contact surfaces also promotes growth and survival of these pathogens for longer period of time in catfish processing industries.

URI

https://hdl.handle.net/11668/20323

Comments

reduction||Growth||disinfectants||mucus||catfish||Salmonella||Listeria monocytogenes||Biofilm

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