Title: Influence of Sterilized Human Fecal Extract on the Sensitivity of Salmonella enterica ATCC 13076 and Listeria monocytogenes ATCC 15313 to Enrofloxacin

Abstract

There is much debate on whether continuous exposure of commensal bacteria and potential pathogens residing in the human intestinal tract to low levels of antimicrobial agents from treated food animals pose a public health concern. To investigate antimicrobial effects on bacteria under colonic conditions, we studied resistance development in Salmonella enterica and Listeria monocytogenes exposed to enrofloxacin in the presence of fecal extract. The bacteria were incubated at 37 °C in Mueller-Hinton broth, with and without 0.01~0.5 μg/mL enrofloxacin, in the presence and absence of sucrose, and with 1% or 2.5% filter-sterilized fecal extract, for three passages. In the second and third passages, only the bacteria incubated in the media containing sterilized fecal extract grew in 0.5 μg/mL of enrofloxacin. Fecal extract (1% and 2.5%) decreased the sensitivity of S. enterica to enrofloxacin in the medium containing the efflux pump inhibitors reserpine and carbonyl cyanide-m-chlorophenylhydrazone (CCCP) and affected the accumulation of ethidium bromide (EtBr) in this bacterium. Enrofloxacin (0.06 µg/mL) and fecal extract altered the composition of fatty acids in S. enterica and L. monocytogenes. We conclude that fecal extract decreased the susceptibilities of S. enterica and L. monocytogenes to concentrations of enrofloxacin higher than the MIC and resulted inmore » rapid resistance selection.« less

Authors:

Ahn, Youngbeom ^[1]; Stuckey, Ryan ^[1]; Sung, Kidon ^[1]; Rafii, Fatemeh ^[1]; Cerniglia, Carl E. ^[1]

---

+ Show Author Affiliations

1. U.S. Food and Drug Administration, Jefferson, AR (United States)

Publication Date:

Mon Dec 02 00:00:00 EST 2013

Research Org.:

Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Biological and Environmental Research (BER). Biological Systems Science Division

OSTI Identifier:

1630060

Resource Type:

Accepted Manuscript

Journal Name:

Antibiotics

Additional Journal Information:

Journal Volume: 2; Journal Issue: 4; Journal ID: ISSN 2079-6382

Publisher:

MDPI

Country of Publication:

United States

Language:

English

Subject:

59 BASIC BIOLOGICAL SCIENCES; fluoroquinolone; enrofloxacin; sterilized human fecal extract; Salmonella; Listeria