TY - JOUR
T1 - Escherichia coli O157:H7 strains isolated from high-event period beef contamination have strong biofilm-forming ability and low sanitizer susceptibility, which are associated with high pO157 plasmid copy number
AU - Wang, Rong
AU - Luedtke, Brandon E.
AU - Bosilevac, Joseph M.
AU - Schmidt, John W.
AU - Kalchayanand, Norasak
AU - Arthur, Terrance M.
N1 - Publisher Copyright:
© 2016, International Association for Food Protection. All rights reserved.
PY - 2016/11
Y1 - 2016/11
N2 - In the meat industry, a high-event period (HEP) is defined as a time period when beef processing establishments experience an increased occurrence of product contamination by Escherichia coli O157:H7. Our previous studies suggested that bacterial biofilm formation and sanitizer resistance might contribute to HEPs. We conducted the present study to further characterize E. coli O157:H7 strains isolated during HEPs for their potential to cause contamination and to investigate the genetic basis for their strong biofilm-forming ability and high sanitizer resistance. Our results show that, compared with the E. coli O157:H7 diversity control panel strains, the HEP strains had a significantly higher biofilm-forming ability on contact surfaces and a lower susceptibility to common sanitizers. No difference in the presence of disinfectant-resistant genes or the prevalence of antibiotic resistance was observed between the HEP and control strains. However, the HEP strains retained significantly higher copy numbers of the pO157 plasmid. A positive correlation was observed among a strain's high plasmid copy number, strong biofilm-forming ability, low sanitizer susceptibility, and high survival and recovery capability after sanitization, suggesting that these specific phenotypes could be either directly correlated to gene expression on the pO157 plasmid or indirectly regulated via chromosomal gene expression influenced by the presence of the plasmid. Our data highlight the potential risk of biofilm formation and sanitizer resistance in HEP contamination by E. coli O157:H7, and our results call for increased attention to proper and effective sanitization practices in meat processing facilities.
AB - In the meat industry, a high-event period (HEP) is defined as a time period when beef processing establishments experience an increased occurrence of product contamination by Escherichia coli O157:H7. Our previous studies suggested that bacterial biofilm formation and sanitizer resistance might contribute to HEPs. We conducted the present study to further characterize E. coli O157:H7 strains isolated during HEPs for their potential to cause contamination and to investigate the genetic basis for their strong biofilm-forming ability and high sanitizer resistance. Our results show that, compared with the E. coli O157:H7 diversity control panel strains, the HEP strains had a significantly higher biofilm-forming ability on contact surfaces and a lower susceptibility to common sanitizers. No difference in the presence of disinfectant-resistant genes or the prevalence of antibiotic resistance was observed between the HEP and control strains. However, the HEP strains retained significantly higher copy numbers of the pO157 plasmid. A positive correlation was observed among a strain's high plasmid copy number, strong biofilm-forming ability, low sanitizer susceptibility, and high survival and recovery capability after sanitization, suggesting that these specific phenotypes could be either directly correlated to gene expression on the pO157 plasmid or indirectly regulated via chromosomal gene expression influenced by the presence of the plasmid. Our data highlight the potential risk of biofilm formation and sanitizer resistance in HEP contamination by E. coli O157:H7, and our results call for increased attention to proper and effective sanitization practices in meat processing facilities.
KW - Biofilm
KW - Escherichia coli O157:H7
KW - High-event period
KW - Sanitizer
KW - pO157 plasmid
UR - http://www.scopus.com/inward/record.url?scp=84992747298&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84992747298&partnerID=8YFLogxK
U2 - 10.4315/0362-028X.JFP-16-113
DO - 10.4315/0362-028X.JFP-16-113
M3 - Article
C2 - 28221917
AN - SCOPUS:84992747298
SN - 0362-028X
VL - 79
SP - 1875
EP - 1883
JO - Journal of food protection
JF - Journal of food protection
IS - 11
ER -