Comparison of agar media for detection and quantification of Shiga toxin-producing Escherichia coli in cattle feces

Zachary R. Stromberg, Gentry L. Lewis, Rodney A. Moxley

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

The isolation and quantification of non-O157 Shiga toxin-producing Escherichia coli (STEC) from cattle feces are challenging. The primary objective of this study was to evaluate the performance of selected agar media in an attempt to identify an optimal medium for the detection and quantification of non-O157 STEC in cattle feces. Comparison studies were performed using CHROMagar STEC, Possé differential agar (Possé), Possé modified by the reduction or addition of antimicrobials, STEC heart infusion washed blood agar with mitomycin C (SHIBAM), and SHIBAM modified by the addition of antimicrobials. Fourteen STEC strains, two each belonging to serogroups O26, O45, O103, O111, O121, O145, and O157, were used to test detection in inoculated fecal suspensions at concentrations of 102 or 103 CFU/g. One STEC strain from each of these seven serogroups was used to estimate the concentration of recovered STEC in feces inoculated at 103, 104, or 105 CFU/g. Significantly more suspensions (P > 0.05) were positive for STEC when plated on Possé containing reduced concentrations of novobiocin and potassium tellurite compared with SHIBAM, but not SHIBAM modified by containing these same antimicrobials at the same concentrations. Numerically, more suspensions were positive for STEC by using this same form of modified Possé compared with Possé, but this difference was not statistically significant. More suspensions were positive for STEC cultured on CHROMagar STEC compared with those on Possé (P > 0.05) and on modified Possé (P = 0.05). Most inoculated fecal suspensions below 104 CFU/g of feces were underestimated or not quantifiable for the concentration of STEC by using CHROMagar STEC or modified Possé. These results suggest that CHROMagar STEC performs better than Possé or SHIBAM for detection of STEC in bovine feces, but adjustments in the concentrations of novobiocin and potassium tellurite in the latter two media result in significant improvements in their performance.

Original languageEnglish (US)
Pages (from-to)939-949
Number of pages11
JournalJournal of food protection
Volume79
Issue number6
DOIs
StatePublished - Jun 2016

Fingerprint

Shiga-Toxigenic Escherichia coli
Shiga toxin-producing Escherichia coli
Feces
Agar
agar
feces
cattle
mitomycin
Mitomycin
heart
Suspensions
blood
novobiocin
anti-infective agents
Novobiocin
serotypes
potassium

Keywords

  • Agar
  • Cattle
  • Escherichia coli
  • Shiga toxin-producing Escherichia coli

ASJC Scopus subject areas

  • Food Science
  • Microbiology

Cite this

Comparison of agar media for detection and quantification of Shiga toxin-producing Escherichia coli in cattle feces. / Stromberg, Zachary R.; Lewis, Gentry L.; Moxley, Rodney A.

In: Journal of food protection, Vol. 79, No. 6, 06.2016, p. 939-949.

Research output: Contribution to journalArticle

@article{654a4f63898c4bd9b25556dbed7f0423,
title = "Comparison of agar media for detection and quantification of Shiga toxin-producing Escherichia coli in cattle feces",
abstract = "The isolation and quantification of non-O157 Shiga toxin-producing Escherichia coli (STEC) from cattle feces are challenging. The primary objective of this study was to evaluate the performance of selected agar media in an attempt to identify an optimal medium for the detection and quantification of non-O157 STEC in cattle feces. Comparison studies were performed using CHROMagar STEC, Poss{\'e} differential agar (Poss{\'e}), Poss{\'e} modified by the reduction or addition of antimicrobials, STEC heart infusion washed blood agar with mitomycin C (SHIBAM), and SHIBAM modified by the addition of antimicrobials. Fourteen STEC strains, two each belonging to serogroups O26, O45, O103, O111, O121, O145, and O157, were used to test detection in inoculated fecal suspensions at concentrations of 102 or 103 CFU/g. One STEC strain from each of these seven serogroups was used to estimate the concentration of recovered STEC in feces inoculated at 103, 104, or 105 CFU/g. Significantly more suspensions (P > 0.05) were positive for STEC when plated on Poss{\'e} containing reduced concentrations of novobiocin and potassium tellurite compared with SHIBAM, but not SHIBAM modified by containing these same antimicrobials at the same concentrations. Numerically, more suspensions were positive for STEC by using this same form of modified Poss{\'e} compared with Poss{\'e}, but this difference was not statistically significant. More suspensions were positive for STEC cultured on CHROMagar STEC compared with those on Poss{\'e} (P > 0.05) and on modified Poss{\'e} (P = 0.05). Most inoculated fecal suspensions below 104 CFU/g of feces were underestimated or not quantifiable for the concentration of STEC by using CHROMagar STEC or modified Poss{\'e}. These results suggest that CHROMagar STEC performs better than Poss{\'e} or SHIBAM for detection of STEC in bovine feces, but adjustments in the concentrations of novobiocin and potassium tellurite in the latter two media result in significant improvements in their performance.",
keywords = "Agar, Cattle, Escherichia coli, Shiga toxin-producing Escherichia coli",
author = "Stromberg, {Zachary R.} and Lewis, {Gentry L.} and Moxley, {Rodney A.}",
year = "2016",
month = "6",
doi = "10.4315/0362-028X.JFP-15-552",
language = "English (US)",
volume = "79",
pages = "939--949",
journal = "Journal of Food Protection",
issn = "0362-028X",
publisher = "International Association for Food Protection",
number = "6",

}

TY - JOUR

T1 - Comparison of agar media for detection and quantification of Shiga toxin-producing Escherichia coli in cattle feces

AU - Stromberg, Zachary R.

AU - Lewis, Gentry L.

AU - Moxley, Rodney A.

PY - 2016/6

Y1 - 2016/6

N2 - The isolation and quantification of non-O157 Shiga toxin-producing Escherichia coli (STEC) from cattle feces are challenging. The primary objective of this study was to evaluate the performance of selected agar media in an attempt to identify an optimal medium for the detection and quantification of non-O157 STEC in cattle feces. Comparison studies were performed using CHROMagar STEC, Possé differential agar (Possé), Possé modified by the reduction or addition of antimicrobials, STEC heart infusion washed blood agar with mitomycin C (SHIBAM), and SHIBAM modified by the addition of antimicrobials. Fourteen STEC strains, two each belonging to serogroups O26, O45, O103, O111, O121, O145, and O157, were used to test detection in inoculated fecal suspensions at concentrations of 102 or 103 CFU/g. One STEC strain from each of these seven serogroups was used to estimate the concentration of recovered STEC in feces inoculated at 103, 104, or 105 CFU/g. Significantly more suspensions (P > 0.05) were positive for STEC when plated on Possé containing reduced concentrations of novobiocin and potassium tellurite compared with SHIBAM, but not SHIBAM modified by containing these same antimicrobials at the same concentrations. Numerically, more suspensions were positive for STEC by using this same form of modified Possé compared with Possé, but this difference was not statistically significant. More suspensions were positive for STEC cultured on CHROMagar STEC compared with those on Possé (P > 0.05) and on modified Possé (P = 0.05). Most inoculated fecal suspensions below 104 CFU/g of feces were underestimated or not quantifiable for the concentration of STEC by using CHROMagar STEC or modified Possé. These results suggest that CHROMagar STEC performs better than Possé or SHIBAM for detection of STEC in bovine feces, but adjustments in the concentrations of novobiocin and potassium tellurite in the latter two media result in significant improvements in their performance.

AB - The isolation and quantification of non-O157 Shiga toxin-producing Escherichia coli (STEC) from cattle feces are challenging. The primary objective of this study was to evaluate the performance of selected agar media in an attempt to identify an optimal medium for the detection and quantification of non-O157 STEC in cattle feces. Comparison studies were performed using CHROMagar STEC, Possé differential agar (Possé), Possé modified by the reduction or addition of antimicrobials, STEC heart infusion washed blood agar with mitomycin C (SHIBAM), and SHIBAM modified by the addition of antimicrobials. Fourteen STEC strains, two each belonging to serogroups O26, O45, O103, O111, O121, O145, and O157, were used to test detection in inoculated fecal suspensions at concentrations of 102 or 103 CFU/g. One STEC strain from each of these seven serogroups was used to estimate the concentration of recovered STEC in feces inoculated at 103, 104, or 105 CFU/g. Significantly more suspensions (P > 0.05) were positive for STEC when plated on Possé containing reduced concentrations of novobiocin and potassium tellurite compared with SHIBAM, but not SHIBAM modified by containing these same antimicrobials at the same concentrations. Numerically, more suspensions were positive for STEC by using this same form of modified Possé compared with Possé, but this difference was not statistically significant. More suspensions were positive for STEC cultured on CHROMagar STEC compared with those on Possé (P > 0.05) and on modified Possé (P = 0.05). Most inoculated fecal suspensions below 104 CFU/g of feces were underestimated or not quantifiable for the concentration of STEC by using CHROMagar STEC or modified Possé. These results suggest that CHROMagar STEC performs better than Possé or SHIBAM for detection of STEC in bovine feces, but adjustments in the concentrations of novobiocin and potassium tellurite in the latter two media result in significant improvements in their performance.

KW - Agar

KW - Cattle

KW - Escherichia coli

KW - Shiga toxin-producing Escherichia coli

UR - http://www.scopus.com/inward/record.url?scp=84974817891&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84974817891&partnerID=8YFLogxK

U2 - 10.4315/0362-028X.JFP-15-552

DO - 10.4315/0362-028X.JFP-15-552

M3 - Article

C2 - 27296597

AN - SCOPUS:84974817891

VL - 79

SP - 939

EP - 949

JO - Journal of Food Protection

JF - Journal of Food Protection

SN - 0362-028X

IS - 6

ER -