UNDERSTANDING SALMONELLA HEIDELBERG (SH) BIOFILM FORMATION AND SUSCEPTIBILITY AND DISINFECTANTS IN A PROCESSING PLANT ENVIRONMENT

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: TERMINATED
• Funding Source: ANIMAL HEALTH
• Reporting Frequency: Annual
• Accession No.: 1005922
• Project No.: CA-V-PHR-4704-AH404
• Project Start Date: Mar 11, 2015
• Project End Date: Sep 30, 2015

Project Director
Pitesky, MA, .

Recipient Organization
UNIVERSITY OF CALIFORNIA, DAVIS
410 MRAK HALL
DAVIS,CA 95616-8671

Performing Department
Population Health & Reproduction

Non Technical Summary
Based on some initial research in our lab in collaboration with a California based broiler company, we have found that field strains of Salmonella Heidelberg form biofilms. In addition, based on some initial exploratory experiments, the biofilms appear to be more resistant to disinfectants than other field strains of Salmonella. Our central hypothesis is that biofilms produced from Salmonella Heidelberg are more resistant than other serotypes of Salmonella. Our long-term goal is to understand the efficacy of different disinfectants, bacteriophages and bacterocins against zoonotic strains of Salmonella under different conditions found in a processing plant (e.g. chiller and dipping station in secondary processing).

Animal Health Component

100%

Research Effort Categories

Basic

(N/A)

Applied

100%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
712	0120	1100	100%

Knowledge Area
712 - Protect Food from Contamination by Pathogenic Microorganisms, Parasites, and Naturally Occurring Toxins;

Subject Of Investigation
0120 - Land;

Field Of Science
1100 - Bacteriology;

Keywords

salmonella heidelberg

biofilm

rna-seq

Goals / Objectives
Based on our central hypothesis that biofilms produced from SH are more resistant than other field strains of Salmonella our objectives are:1. Characterize biofilm formation of multiple field strains of Salmonella isolated from live production and processing2. Determine the sensitivity of biofilms to commonly used disinfectants, bacteriophages and bacterocins under processing plant conditions.3. In collaboration with Huaijun Zhou in UC Davis Animal Science Department, use RNA-seq to identify differences in gene expression in biofilm forming Salmonella following a challenge with commonly used disinfectants4. Communicate information to commercial poultry companies

Project Methods
Phase I: In collaboration with a broiler company, utilize their 'library' of Salmonella field strains to determine the ability of these field strains to form biofilms. This will be done using the Innovotech MBECTM assay kit which measures biofilm growth on polystyrene pegs4. Phase II: Expose biofilm to common disinfectants under processing plant conditions in order to determine the sensitivity of each field strain of Salmonella to disinfectants used in a processing plant including PAA, aCH, and Cecure® and Salmonella specific bacteriophage and bacterocins. This will also be done via the Innovotech MBECTM assay kit4. Specifically, once the biofilm is formed on the polystyrene peg, the peg can be exposed to the disinfectant for times and temperatures consistent with a processing plant environment. Sensitivity can be determined via a standard spectrophotometric assay.Phase III: RNA-seq Next Generation Sequencing will be performed in collaboration with Dr. Huaijun Zhou;s lab of the biofilms exposed and unexposed to the disinfectant in order to better understand how the living biofilms are surviving the disinfectant challenge. This will help identify what resistance genes are expressed when the biofilms are challenged with disinfectants.

Progress 03/11/15 to 09/30/15

Outputs
Target Audience:Commercial poultry processing companies Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?Results were presented at the 2016 Western Poultry Diseease Conference in Sacramento California. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? The research and publication showed that under simulated poultry processing conditiions that pathogenic Salmonella in their biofilm state are resistant to commonly used disinfectants at concentrations and contact times commonly used in poultry processing plants. While planktonic bacteria were sensitive to these disinfectants, Salmonella in their biofilm state are more commonly found in poultry and poultry processing.

Publications

• Type: Journal Articles Status: Published Year Published: 2017 Citation: Tereza Chylkova, Myrna Cadena, Aura Ferreiro, and Maurice Pitesky (2017) Susceptibility of Salmonella Biofilm and Planktonic Bacteria to Common Disinfectant Agents Used in Poultry Processing. Journal of Food Protection: July 2017, Vol. 80, No. 7, pp. 1072-1079.

Progress 03/11/15 to 09/30/15

Outputs
Target Audience:The target audience for this project are poultry producers. We have shared the initial results of this study with the largest commercial poultry producer in the state of California. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?I have been able to meet twice with a major commercial poultry production company in California to discuss the relevance of the results for their current processing. We plan to share the results at the 2016 Western Poultry Disease Conference in Vancuver, CA. In addition, we paln to submit an article to the Journal of Food Protection in the coming year. How have the results been disseminated to communities of interest?I have been able to meet twice with a major commercial poultry production company in California to discuss the relevance of the results for their current processing. We plan to share the results at the 2016 Western Poultry Disease Conference in Vancuver, CA. In addition, we paln to submit an article to theJournal of Food Protectionin the coming year. What do you plan to do during the next reporting period to accomplish the goals?Work on finalizing a manuscript for publication in theJournal of Food Protection?

Impacts
What was accomplished under these goals? The following goals were accomplished: Identification of biofilm formers from field strains of Salmonella The Mean Inhibitory Concentration (MIC) of each field strain of Salmonella was identified using three commonly used disinfectants at various concentrations. These results help us identify at what concentration bacterialcidal activity occured at for planktonic Salmonella. The Mean Biofilm Inhibitory Concentration (MBIC) of each field strain ofSalmonellawas identified using three commonly used disinfectants at various concentrations.These results help us identify at what concentration bacterialcidal activity occured at forSalmonellathat were Salmonella. The log reduction of each field strain ofSalmonellawas identified using three commonly used disinfectants at various concentrations. These results help us identify bacteriostatic concentrations of various disinfectants. In general the biofilms were significantly more resistant to disinfectants than the planktonic bacteria. In general the Salmonella Heidelberg strains were not more resistant to disinfectants than other tested Salmonella.

Publications