Modelling of tetracycline resistance gene transfer by commensal <i>Escherichia coli</i> food isolates that survived in gastric fluid conditions

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>Antimicrobial resistance (AR) is a major public health concern and a food safety issue worldwide. <I>Escherichia coli</I> strains, indicators of antibiotic resistance, are a source of horizontal gene transfer to other bacteria in the human intestinal system. A probabilistic exposure model was used to estimate the transfer of the AR gene <I>tet</I>(A). The acid resistance and kinetic behaviour of <I>E. coli</I> was analysed as a function of pH to describe the inactivation of <I>E. coli</I> in simulated gastric fluid (SGF), the major host barrier against exogenous micro-organisms. The kinetic parameters of microbial inactivation in SGF were estimated using GInaFiT, and log-linear + tail and Weibull models were found to be suitable for commensal and enterohaemorrhagic <I>E. coli</I> (EHEC), respectively. A probabilistic exposure model was developed to estimate <I>E. coli</I> survival in gastric pH conditions as well as gene transfer from resistant to susceptible cells in humans. <I>E. coli</I>-contaminated retail foods for consumption without further cooking and gastric pH data in South Korea were considered as an example. The model predicts that 22–33% of commensal <I>E. coli</I> can survive under gastric pH conditions of Koreans. The estimated total mean <I>tet</I>(A) transfer level by commensal <I>E. coli</I> was 1.68 × 10<SUP>–4</SUP>–8.15 × 10<SUP>–4</SUP> log CFU/mL/h. The inactivation kinetic parameters of <I>E. coli</I> in SGF and the quantitative exposure model can provide useful information regarding risk management options to control the spread of AR.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Probabilistic exposure model was used to estimate antimicrobial resistance gene transfer in the human gut. </LI> <LI> Acid resistance and kinetic behaviour of <I>E. coli</I> survival were analysed in gastric pH conditions. </LI> <LI> Simulation results suggest that 22–33% of commensal <I>E. coli</I> can survive under gastric pH conditions of Koreans. </LI> <LI> Estimated mean <I>tet</I>(A) transfer rate by commensal <I>E. coli</I> was 1.68 × 10<SUP>–4</SUP>–8.15 × 10<SUP>–4</SUP> log CFU/mL/h. </LI> </UL> </P>