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Microcin M cc PDI reduces the prevalence of susceptible E scherichia coli in neonatal calves
Author(s) -
Eberhart L.J.,
Ochoa J.N.,
Besser T.E.,
Call D.R.
Publication year - 2014
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1111/jam.12535
Subject(s) - escherichia coli , biology , microbiology and biotechnology , in vivo , pathogenic escherichia coli , strain (injury) , enterobacteriaceae , bacteria , population , inoculation , feces , fermentation , pathogenic bacteria , serotype , food science , gene , genetics , immunology , demography , sociology , anatomy
Aims Microcin M cc PDI ‐producing E scherichia coli have a fitness advantage in dairy calves. For this project, we determined whether M cc PDI is responsible for the in vivo fitness advantage, which is a necessary condition before M cc PDI strains can be considered viable candidates for inhibiting pathogenic serovars of E . coli . Methods and Results Neonatal calves were coinoculated with either M cc PDI ‐producing E . coli or M cc PDI ‐knockout mutants in conjunction with a susceptible strain. After 6 days, the M cc PDI ‐producing E. coli‐ 25 strain clearly dominated the E . coli ‐186 susceptible strain in the inoculated calves ( P = 0·003). Mcc PDI ‐producing E . coli composed a higher log percentage of the total population of lactose‐fermenting bacteria in the faeces (5·51 log CFU per 8·03 log CFU) compared with the knockout strain (2·6 log CFU per 8·23 log CFU) ( P = 0·01), and it was more consistently recovered from the lower gastrointestinal tract at the time of necropsy ( P = 0·01). Conclusion Our findings support the hypothesis that M cc PDI is functional in vivo and it is most likely responsible for a fitness advantage in vivo . Significance and Impact of the Study Mcc PDI ‐producing E . coli strongly inhibit pathogenic E . coli strains in vitro . We show herein that M cc PDI functions in vivo, and thus, these strains may be candidate probiotics against pathogenic strains of E . coli .