title: Metabolic parameters linked by phenotype microarray to acid resistance profiles of poultry-associated Salmonella enterica.
abstract: Phenotype microarrays were analyzed for 51 datasets derived from Salmonella enterica. The top 4 serotypes associated with poultry products and one associated with turkey, respectively Typhimurium, Enteritidis, Heidelberg, Infantis and Senftenberg, were represented. Datasets were partitioned initially into two clusters based on ranking by values at pH 4.5 (PM10 A03). Negative control wells were used to establish 90 respiratory units as the point differentiating acid resistance from sensitive strains. Thus, 24 isolates that appeared most acid-resistant were compared initially to 27 that appeared most acid-sensitive (24 × 27 format). Paired cluster analysis was also done and it included the 7 most acid-resistant and -sensitive datasets (7 × 7 format). Statistical analyses of ranked data were then calculated in order of standard deviation, probability value by the Student's t-test and a measure of the magnitude of difference called effect size. Data were reported as significant if, by order of filtering, the following parameters were calculated: i) a standard deviation of 24 respiratory units or greater from all datasets for each chemical, ii) a probability value of less than or equal to 0.03 between clusters and iii) an effect size of at least 0.50 or greater between clusters. Results suggest that between 7.89% and 23.16% of 950 chemicals differentiated acid-resistant isolates from sensitive ones, depending on the format applied. Differences were more evident at the extremes of phenotype using the subset of data in the paired 7 × 7 format. Results thus provide a strategy for selecting compounds for additional research, which may impede the emergence of acid-resistant Salmonella enterica in food.
authors.affiliation: US Department of Agriculture, US National Poultry Research Laboratory, 950 College Station Road, Athens, GA, 30605, USA. Electronic address: Jean.guard@ars.usda.gov.
authors.forename: Jean
authors.initials: J
authors.lastname: Guard
authors.affiliation: US Department of Agriculture, US National Poultry Research Laboratory, 950 College Station Road, Athens, GA, 30605, USA. Electronic address: Michael.rothrock@ars.usda.gov.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Rothrock
authors.affiliation: Washington State University, Pullman, WA, USA. Electronic address: dshah@vetmed.wsu.edu.
authors.forename: Devendra H
authors.initials: DH
authors.lastname: Shah
authors.affiliation: US Department of Agriculture, US National Poultry Research Laboratory, 950 College Station Road, Athens, GA, 30605, USA. Electronic address: deana.jones@ars.usda.gov.
authors.forename: Deana R
authors.initials: DR
authors.lastname: Jones
authors.affiliation: US Department of Agriculture, US National Poultry Research Laboratory, 950 College Station Road, Athens, GA, 30605, USA. Electronic address: Richard.gast@ars.usda.gov.
authors.forename: Richard K
authors.initials: RK
authors.lastname: Gast
authors.affiliation: CEVA, Lenexa, KS, USA. Electronic address: Roxana.sanchez@ceva.com.
authors.forename: Roxana
authors.initials: R
authors.lastname: Sanchez-Ingunza
authors.affiliation: CEVA, Lenexa, KS, USA. Electronic address: Melissa.madsen@ceva.com.
authors.forename: Melissa
authors.initials: M
authors.lastname: Madsen
authors.affiliation: CEVA, Lenexa, KS, USA. Electronic address: john.elattrache@ceva.com.
authors.forename: John
authors.initials: J
authors.lastname: El-Attrache
authors.affiliation: University of California, Davis, CA, USA. Electronic address: blungu@ucdavis.edu.
authors.forename: Bwalya
authors.initials: B
authors.lastname: Lungu
mesh_terms: D000143:Acids / Q000378:metabolism*; D000818:Animals; D001431:Bacteriological Techniques; D004361:Drug Tolerance; D008461:Meat Products / Q000382:microbiology; D055442:Metabolome; D046228:Microarray Analysis; D010641:Phenotype; D011200:Poultry / Q000382:microbiology*; D019779:Salmonella enterica / Q000187:drug effects* / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D000143:Acids
keywords: Acid tolerance; Food safety; Metabolism; Phenotype; Poultry; Salmonella