Heather K. Allen

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  • Heather K. Allen, Torey Looft, Darrell O. Bayles, Samuel Humphrey, Uri Y. Levine, David Alt +1 other
  • 2011
UNLABELLED Antibiotics are a cost-effective tool for improving feed efficiency and preventing disease in agricultural animals, but the full scope of their collateral effects is not understood. Antibiotics have been shown to mediate gene transfer by inducing prophages in certain bacterial strains; therefore, one collateral effect could be prophage induction(More)
MOTIVATION The massive data produced by next-generation sequencing require advanced statistical tools. We address estimating the total diversity or species richness in a population. To date, only relatively simple methods have been implemented in available software. There is a need for software employing modern, computationally intensive statistical(More)
BACKGROUND Viruses are important drivers of ecosystem functions, yet little is known about the vast majority of viruses. Viral shotgun metagenomics enables the investigation of broad ecological questions in phage communities. One ecological characteristic is species richness, which is the number of different species in a community. Viruses do not have a(More)
Antibiotics are an essential component of the modern lifestyle. They improve our lives by treating disease, preventing disease, and in the case of agricultural animals by improving feed efficiency. However, antibiotic usage is not without collateral effects. The development and spread of antibiotic resistance is the most notorious concern associated with(More)
Antibiotics are used in livestock and poultry production to treat and prevent disease as well as to promote animal growth. Carbadox is an in-feed antibiotic that is widely used in swine production to prevent dysentery and to improve feed efficiency. The goal of this study was to characterize the effects of carbadox and its withdrawal on the swine gut(More)
Antibiotics are used for disease therapeutic or preventative effects in humans and animals, as well as for enhanced feed conversion efficiency in livestock. Antibiotics can also cause undesirable effects in microbial populations, including selection for antibiotic resistance, enhanced pathogen invasion, and stimulation of horizontal gene transfer. Carbadox(More)
We consider the classical population diversity estimation scenario based on frequency count data (the number of classes or taxa represented once, twice, etc. in the sample), but with the proviso that the lowest frequency counts, especially the singletons, may not be reliably observed. This arises especially in data derived from modern high-throughput DNA(More)
The nature of life is change. Organisms change developmentally , morphologically, and physiologically, and they also modify their environments in the process. Such change can be gradual, abrupt, or even imperceptible components of steady states. Temporally, change can range from deterministic and regular processes to stochastic and unusual events. Unusual(More)
Profiling of 16S rRNA gene sequences is an important tool for testing hypotheses in complex microbial communities, and analysis methods must be updated and validated as sequencing technologies advance. In host-associated bacterial communities, the V1–V3 region of the 16S rRNA gene is a valuable region to profile because it provides a useful level of(More)
Functional metagenomic analysis of soil metagenomes is a method for uncovering as-yet unidentified mechanisms for antibiotic resistance. Here we report an unconventional mode by which a response regulator derived from a soil metagenome confers resistance to the β-lactam antibiotic carbenicillin in Escherichia coli. A recombinant clone (βlr16) harboring a(More)