Amy Langdon

• Washington University in St. Louis

Background Children with severe acute malnutrition are treated with antibiotics as outpatients. We aimed to determine the effect of 7 days of amoxicillin on acute and long-term changes to the gut microbiome and antibiotic resistome in children treated for severe acute malnutrition. Methods We conducted a secondary analysis of a randomised, double-...

Background Once antibiotic-resistant bacteria become established within the gut microbiota, they can cause infections in the host and be transmitted to other people and the environment. Currently, there are no effective modalities for decreasing or preventing colonization by antibiotic-resistant bacteria. Intestinal microbiota restoration can preve...

The spread of multidrug resistance among pathogenic organisms threatens the efficacy of antimicrobial treatment options. The human gut serves as a reservoir for many drug-resistant organisms and their resistance genes, and perturbation of the gut microbiome by antimicrobial exposure can open metabolic niches to resistant pathogens. Once established...

OBJECTIVES/SPECIFIC AIMS: A course of oral broad-spectrum antibiotics frequently has a positive effect on morbidity and mortality in severe acute malnutrition (SAM), but the actual mechanism for this effect is unknown. This mechanism is especially important to find and quantify because of the possibility that using antibiotics prophylactically may...

OBJECTIVES/SPECIFIC AIMS: Clostridium difficile is the most common cause of infectious antibiotic associated diarrhea. It is often refractory to antimicrobial therapy and fecal microbiota transplantation (FMT) is emerging as a therapeutic option. The objective is to characterize the direct effects of FMT on the gut microbiota. METHODS/STUDY POPULAT...

The widespread use of antibiotics in the past 80 years has saved millions of human lives, facilitated technological progress and killed incalculable numbers of microbes, both pathogenic and commensal. Human-associated microbes perform an array of important functions, and we are now just beginning to understand the ways in which antibiotics have res...

Significance Genomic structural variants (SVs) significantly contribute to human genetic variation and have been linked with numerous diseases. Compared with humans, the characterization of SVs occurring within and across nonhuman primates has lagged. We generated comprehensive massively parallel DNA sequencing-based SV maps in three nonhuman prima...

Stringency of L. ochracea specific FISH probe, Lepto175 to L. ochracea cells present in LD mat samples collected August 2008 (closed symbols) and O. thiooxydans cells grown in R2A (open circles (check a)) or caso- agar (open squares (check b)). The relative fluorescence was normalized to hybridizations performed at 5% or 0% formamide. Hybridization...

The ability of FISH probes to bind to select species of the Betaproteobacteria. (DOC)

Neighbor-joining tree of a partial SSU rRNA gene sequence from non-chimeric clones and single amplified genomes of bacteria. The tree was generated using the ARB neighbor joining package with Jukes-Cantor correction. Percentages represent the bootstrap values at each node for 1000 replicate trees and percentages less than 50% are not shown. Origina...

Information regarding additional materials and methods used to generate SSU rRNA gene sequence clone libraries, to analyze the sequence reads, develop the Lepto175 and to perform FISH on Lakeside Drive iron-mat samples. (DOC)

Flow cytometry dot plot of the Fe-oxidizing mat sample stained with SYTO-9 (A) and excited with a 488 nm laser. Displayed are side scatter (SSC) and green fluorescence (FL1) signals. Region R3 was used as the sorting gate. Phase contrast (B) and epifluorescence micrographs of the sorted material (C). Mat samples for single cell genomics were also c...

Leptothrix ochracea is a common inhabitant of freshwater iron seeps and iron-rich wetlands. Its defining characteristic is copious production of extracellular sheaths encrusted with iron oxyhydroxides. Surprisingly, over 90% of these sheaths are empty, hence, what appears to be an abundant population of iron-oxidizing bacteria, consists of relative...