title: Effect of antibiotic pre-treatment and pathogen challenge on the intestinal microbiota in mice.
abstract: BACKGROUND
  More than 50 years after the discovery of antibiotics, bacterial infections have decreased substantially; however, antibiotics also may have negative effects such as increasing susceptibility to pathogens. An intact microbiome is an important line of defense against pathogens. We sought to determine the effect of orally administered antibiotics both on susceptibility to pathogens and on impact to the microbiome. We studiedCampylobacter jejuni, one of the most common causes of human diarrhea, andAcinetobacter baumannii, which causes wound infections. We examined the effects of antibiotic treatment on the susceptibility of mice to those pathogens as well as their influence on the mouse gut microbiome.
  
  
  RESULTS
  In C57/BL6 mice models, we explored the effects of pathogen challenge, and antibiotic treatment on the intestinal microbiota. Mice were treated with either ciprofloxacin, penicillin, or water (control) for a 5-day period followed by a 5-day washout period prior to oral challenge withC. jejuniorA. baumanniito assess antibiotic effects on colonization susceptibility. Mice were successfully colonized withC. jejunimore than 118 days, but only transiently withA. baumannii. These challenges did not lead to any major effects on the composition of the gut microbiota. Although antibiotic pre-treatment did not modify pathogen colonization, it affected richness and community structure of the gut microbiome. However, the antibiotic dysbiosis was significantly reduced by pathogen challenge.
  
  
  CONCLUSIONS
  We conclude that despite gut microbiota disturbance, susceptibility to gut colonization by these pathogens was unchanged. The major gut microbiome disturbance produced by antibiotic treatment may be reduced by colonization with specific microbial taxa.
authors.affiliation: Department of Medicine, New York University School of Medicine, New York, NY USA ; 6026 W VAMC, 423 East 23th Street, New York, NY 10010 USA.
authors.forename: Tadasu
authors.identifier: 0000-0003-4939-9510
authors.initials: T
authors.lastname: Iizumi
authors.affiliation: Department of Agriculture, University of Miyazaki, Miyazaki, Japan.
authors.forename: Takako
authors.initials: T
authors.lastname: Taniguchi
authors.affiliation: Department of Agriculture, University of Miyazaki, Miyazaki, Japan.
authors.forename: Wataru
authors.initials: W
authors.lastname: Yamazaki
authors.affiliation: Universite Montpellier, Montpellier, France.
authors.forename: Geraldine
authors.initials: G
authors.lastname: Vilmen
authors.affiliation: Department of Medicine, New York University School of Medicine, New York, NY USA.
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Alekseyenko
authors.affiliation: Department of Medicine, New York University School of Medicine, New York, NY USA.
authors.forename: Zhan
authors.initials: Z
authors.lastname: Gao
authors.affiliation: Department of Medicine, New York University School of Medicine, New York, NY USA.
authors.forename: Guillermo I
authors.initials: GI
authors.lastname: Perez Perez
authors.affiliation: Department of Medicine, New York University School of Medicine, New York, NY USA ; Department of Microbiology, New York University School of Medicine, New York, NY USA.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Blaser
keywords: Acinetobacter baumannii; Antibiotic treatment; Campylobacter jejuni; Ciprofloxacin; High-throughput sequencing; Microbiome; Next-generation sequencing; Pathogen challenge; Penicillin