Title: Effect of citrus by-products on growth of O157:H7 and non-O157 Escherichia coli serogroups within in vitro bovine ruminal microbial fermentations

Authors: Duoss HA, Schmidt TB, Callaway TR, Carroll JA, Martin JM, Shields-Menard SA, Broadway PR, Donaldson JR

Journal: Int J Microbiol

Accepted date: 2013 Jan 8

Interpretive summary: Bovine ruminal fluid can contain E. coli O157 and other pathogenic bacteria. Citrus by-products contain essential oils that possess antimicrobial activities that can exert damage to the cell wall of gram-negative bacteria, such as E. coli. Inclusion of citrus by-products (CBP) in the diets of cattle has been reported to alter the rumen and intestinal gram-negative microbial populations. This alteration to gram-negative microbes has resulted in CBP being investigated as a potential pre-harvest pathogen intervention strategy to reduce Shiga toxin-producing Escherichia coli (STEC) populations. Therefore, our hypothesis was that CBP might decrease STEC populations with varying degrees between non-O157 STEC serogroups when cultured within ruminal microbial fermentations (RMF). CBP decreased populations of O103:H8 O157:H7 delta-stx1 stx2, and O103:H8 in the presence of >5% powdered CBP, but not other STECs. Further research is needed to determine how the various STEC survive within RMF when supplemented with CBP.

Publication date: 2013 Jan

Volume: 2013

Pages: 398320