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Through infection and lysis of their coexisting bacterial hosts, viruses impact the biogeochemical cycles sustaining globally significant pelagic oceanic ecosystems. Currently, little is known of the ecological interactions between lytic viruses and their bacterial hosts underlying these biogeochemical impacts at ecosystem scales. This study focused on populations of lytic viruses carrying the B12- dependent Class II monomeric ribonucleotide reductase (RNR) gene, ribonucleotide triphosphate reductase (RTPR), documenting seasonal changes in pelagic virioplankton and bacterioplankton using amplicon sequences of RTPR and the 16S rRNA gene, respectively. Amplicon sequence libraries were analyzed using compositional data analysis tools that account for the compositional nature of these data. Both virio- and bacterioplankton communities responded to environmental changes typically seen across seasonal cycles as well as shorter term upwelling–downwelling events. Defining RTPR-carrying viral populations according to major phylogenetic clades proved a more robust means of exploring virioplankton ecology than operational taxonomic units defined by percent sequence homology. Virioplankton RTPR populations showed positive associations with a broad phylogenetic diversity of bacterioplankton including dominant taxa within pelagic oceanic ecosystems such asProchlorococcusand SAR11. Temporal changes in RTPR-virioplankton, occurring as both free viruses and within infected cells, indicated possible viral–host pairs undergoing sustained infection and lysis cycles throughout the seasonal study. Phylogenetic relationships inferred from RTPR sequences mirrored ecological patterns in virio- and bacterioplankton populations demonstrating possible genome to phenome associations for an essential viral replication gene.

Background Human immunodeficiency virus (HIV)-associated lipodystrophy is a known consequence of long-term highly active antiretroviral therapy (HAART). However, a significant number of patients on HAART therapy were left with the stigmata of complications, including fat redistribution. Few studies have described the successful removal of focal areas of lipohypertrophy with successful outcomes. This manuscript reviews the outcomes of excisional lipectomy versus liposuction for HIV-associated cervicodorsal lipodystrophy. Methods We performed a 15-year retrospective review of HIV-positive patients with lipodystrophy. Patients were identified by query of secure operative logs. Data collected included demographics, medications, comorbidities, duration of HIV, surgical intervention type, pertinent laboratory values, and the amount of tissue removed. Results Nine male patients with HIV-associated lipodystrophy underwent a total of 17 procedures. Of the patients who underwent liposuction initially (n=5), 60% (n=3) experienced a recurrence. There were a total of three cases of primary liposuction followed by excisional lipectomy. One hundred percent of these cases were noted to have a recurrence postoperatively, and there was one case of seroma formation. Of the subjects who underwent excisional lipectomy (n=4), there were no documented recurrences; however, one patient’s postoperative course was complicated by seroma formation. Conclusions HIV-associated lipodystrophy is a disfiguring complication of HAART therapy with significant morbidity. Given the limitations of liposuction alone as the primary intervention, excisional lipectomy is recommended as the primary treatment. Liposuction may be used for better contouring and for subsequent procedures. While there is a slightly higher risk for complications, adjunctive techniques such as quilting sutures and placement of drains may be used in conjunction with excisional lipectomy.

Understanding how phenotypes emerge from genotypes is a foundational goal in biology. As challenging as this task is when considering cellular life, it is further complicated in the case of viruses. During replication, a virus as a discrete entity (the virion) disappears and manifests itself as a metabolic amalgam between the virus and the host (the virocell). Identifying traits that unambiguously constitute a virus’s phenotype is straightforward for the virion, less so for the virocell. Here, we present a framework for categorizing virus phenotypes that encompasses both virion and virocell stages and considers functional and performance traits of viruses in the context of fitness. Such an integrated view of virus phenotype is necessary for comprehensive interpretation of viral genome sequences and will advance our understanding of viral evolution and ecology. Linking genotype to phenotype is particularly challenging for viruses because of their small size, sparse phenotypic data and interlinked viral, host and environmental factors. In this Review, DeLong and colleagues discuss traits of virions and virocells and phenotypic plasticity.

Understanding how phenotypes emerge from genotypes is a foundational goal in biology. As challenging as this task is when considering cellular life, it is further complicated in the case of viruses. During replication, a virus as a discrete entity (the virion) disappears and manifests itself as a metabolic amalgam between the virus and the host (the virocell). Identifying traits that unambiguously constitute a virus's phenotype is straightforward for the virion, less so for the virocell. Here, we present a framework for categorizing virus phenotypes that encompasses both virion and virocell stages and considers functional and performance traits of viruses in the context of fitness. Such an integrated view of virus phenotype is necessary for comprehensive interpretation of viral genome sequences and will advance our understanding of viral evolution and ecology.

BackgroundIncreasingly, researchers use protein-coding genes from targeted PCR amplification or direct metagenomic sequencing in community and population ecology. Analysis of protein-coding genes presents different challenges from those encountered in traditional SSU rRNA studies. Most protein-coding sequences are annotated based on homology to other computationally-annotated sequences, which can lead to inaccurate annotations. Therefore, the results of sensitive homology searches must be validated to remove false-positives and assess functionality. Multiple lines of in silico evidence can be gathered by examining conserved domains and residues identified through biochemical investigations. However, manually validating sequences in this way can be time consuming and error prone, especially in large environmental studies.ResultsAn automated pipeline for protein active site validation (PASV) was developed to improve validation and partitioning accuracy for protein-coding sequences, combining multiple sequence alignment with expert domain knowledge. PASV was tested using commonly misannotated proteins: ribonucleotide reductase (RNR), alternative oxidase (AOX), and plastid terminal oxidase (PTOX). PASV partitioned 9,906 putative Class I alpha and Class II RNR sequences from bycatch in a global viral metagenomic investigation with >99% true positive and true negative rates. PASV predicted the class of 2,579 RNR sequences in >98% agreement with manual annotations. PASV correctly partitioned all 336 tested AOX and PTOX sequences.ConclusionsPASV provides an automated and accurate way to address post-homology search validation and partitioning of protein-coding marker genes. Source code is released under the MIT license and is found with documentation and usage examples on GitHub at https://github.com/mooreryan/pasv.

Big data abound in microbiology, but the workflows designed to enable researchers to interpret data can constrain the biological questions that can be asked. Five years after anvi'o was first published, this community-led multi-omics platform is maturing into an open software ecosystem that reduces constraints in 'omics data analyses. Non

Vascular compromise and blindness are reported but rare complications of facial soft tissue filler injections. Stroke is an even rarer complication resulting from intraarterial injection of fillers. We present a case of a patient suffering all 3 complications following hyaluronic acid filler injection: forehead skin vascular compromise, unilateral blindness, and ipsilateral subclinical strokes. Were it not for a stroke workup protocol, the incidental strokes may have otherwise gone undetected, suggesting the incidence of stroke from intraarterial injection may be higher than reported. Further, we review the literature and recommendations for prevention and management of threatened tissue ischemia and vision loss from facial filler injection. Level of Evidence: 5

We investigated the nascent application and efficacy of sampling and sequencing environmental DNA (eDNA) in terrestrial environments using rainwater that filters through the forest canopy and understory vegetation (i.e., throughfall). We demonstrate the utility and potential of this method for measuring microbial communities and forest biodiversity. We collected pure rainwater (open sky) and throughfall, successfully extracted DNA, and generated over 5000 unique amplicon sequence variants. We found that several taxa including Mycoplasma sp., Spirosoma sp., Roseomonas sp., and Lactococcus sp. were present only in throughfall samples. Spiroplasma sp., Methylobacterium sp., Massilia sp., Pantoea sp., and Sphingomonas sp. were found in both types of samples, but more abundantly in throughfall than in rainwater. Throughfall samples contained Gammaproteobacteria that have been previously found to be plant-associated, and may contribute to important functional roles. We illustrate how this novel method can be used for measuring microbial biodiversity in forest ecosystems, foreshadowing the utility for quantifying both prokaryotic and eukaryotic lifeforms. Leveraging these methods will enhance our ability to detect extant species, describe new species, and improve our overall understanding of ecological community dynamics in forest ecosystems.

Phylogenetic trees are an important analytical tool for evaluating community diversity and evolutionary history. In the case of microorganisms, the decreasing cost of sequencing has enabled researchers to generate ever-larger sequence datasets, which in turn have begun to fill gaps in the evolutionary history of microbial groups. However, phylogenetic analyses of these types of datasets create complex trees that can be challenging to interpret. Scientific inferences made by visual inspection of phylogenetic trees can be simplified and enhanced by customizing various parts of the tree. Yet, manual customization is time-consuming and error prone, and programs designed to assist in batch tree customization often require programming experience or complicated file formats for annotation. Iroki, a user-friendly web interface for tree visualization, addresses these issues by providing automatic customization of large trees based on metadata contained in tab-separated text files. Iroki’s utility for exploring biological and ecological trends in sequencing data was demonstrated through a variety of microbial ecology applications in which trees with hundreds to thousands of leaf nodes were customized according to extensive collections of metadata. The Iroki web application and documentation are available at https://www.iroki.net or through the VIROME portal (http://virome.dbi.udel.edu). Iroki’s source code is released under the MIT license and is available at https://github.com/mooreryan/iroki.

Preoperative evaluation and management of complex perineal wounds must account for any history of previous surgery, radiation, or trauma; the size and surface area following resection or debridement; and the loss of function or structural integrity. The gracilis muscle or myocutaneous flap is a local, well-vascularized option suitable for perineal soft tissue reconstruction, particularly for moderately sized defects of the groin. The use of functional gracilis muscle for anal sphincter reconstruction may also be considered for the treatment of fecal incontinence due to significant neurologic, traumatic, or iatrogenic injury, as well as for congenital abnormalities.

Orthognathic surgery restores the facial function and aesthetics affected by skeletal and dental deformities. A comprehensive preoperative evaluation, including cephalometric analysis, is essential to correcting facial skeletal imbalance and asymmetry. Operative planning must account for maxillary-to-mandibular occlusal relationship and dental compensations, as well as facial proportions in all dimensions. Virtual surgical planning has recently emerged as a way to facilitate more precise and accurate surgical planning. Operative techniques used to correct facial skeletal and dental deformities, broadly categorized as maxillary or mandibular excess or deficiency, include the LeFort I osteotomy, bilateral sagittal split osteotomy, and genioplasty.

Ribonucleotide reductases (RNRs) are ancient enzymes that catalyze the reduction of ribonucleotides to deoxyribonucleotides. They are required for virtually all cellular life and are prominent within viral genomes. RNRs share a common ancestor and must generate a protein radical for direct ribonucleotide reduction. The mechanisms by which RNRs produce radicals are diverse and divide RNRs into three major classes and several subclasses. The diversity of radical generation methods means that cellular organisms and viruses typically contain the RNR best-suited to the environmental conditions surrounding DNA replication. However, such diversity has also fostered high rates of RNR misannotation within subject sequence databases. These misannotations have resulted in incorrect translative presumptions of RNR biochemistry and have diminished the utility of this marker gene for ecological studies of viruses. We discovered a misannotation of the RNR gene within theProchlorococcusphage P-SSP7 genome, which caused a chain of misannotations within commonly observed RNR genes from marine virioplankton communities. These RNRs are found in marine cyanopodo- and cyanosiphoviruses and are currently misannotated as Class II RNRs, which are O2-independent and require cofactor B12. In fact, these cyanoviral RNRs are Class I enzymes that are O2-dependent and may require a di-metal cofactor made of Fe, Mn, or a combination of the two metals. The discovery of an overlooked Class I β subunit in the P-SSP7 genome, together with phylogenetic analysis of the α and β subunits confirms that the RNR from P-SSP7 is a Class I RNR. Phylogenetic and conserved residue analyses also suggest that the P-SSP7 RNR may constitute a novel Class I subclass. The reannotation of the RNR clade represented by P-SSP7 means that most lytic cyanophage contain Class I RNRs, while their hosts, B12-producingSynechococcusandProchlorococcus, contain Class II RNRs. By using a Class I RNR, cyanophage avoid a dependence on host-produced B12, a more effective strategy for a lytic virus. The discovery of a novel RNR β subunit within cyanopodoviruses also implies that some unknown viral genes may be familiar cellular genes that are too divergent for homology-based annotation methods to identify.

The CRISPR-Cas system is one means by which bacterial and archaeal populations defend against viral infection which causes 20 to 50% of cell mortality in the ocean. We tested the hypothesis that certain viral genes are preferentially targeted for the initial attack of the CRISPR-Cas system on a viral genome. Using CASC, a pipeline for CRISPR spacer discovery, and metagenome data from oceanic microbes and viruses, we found a clear subset of viral genes with high match frequencies to CRISPR spacers. Moreover, we observed a many-to-many relationship of spacers and viral genes. These high-match viral genes were involved in nucleotide metabolism, DNA methylation, and viral structure. It is possible that CRISPR spacer matching is an evolutionary algorithm pointing to those viral genes most important to sustaining infection and lysis. Studying these genes may advance the understanding of virus-host interactions in nature and provide new technologies for leveraging CRISPR-Cas systems in beneficial microbes., Viral infection exerts selection pressure on marine microbes, as virus-induced cell lysis causes 20 to 50% of cell mortality, resulting in fluxes of biomass into oceanic dissolved organic matter. Archaeal and bacterial populations can defend against viral infection using the clustered regularly interspaced short palindromic repeat (CRISPR)-associated (Cas) system, which relies on specific matching between a spacer sequence and a viral gene. If a CRISPR spacer match to any gene within a viral genome is equally effective in preventing lysis, no viral genes should be preferentially matched by CRISPR spacers. However, if there are differences in effectiveness, certain viral genes may demonstrate a greater frequency of CRISPR spacer matches. Indeed, homology search analyses of bacterioplankton CRISPR spacer sequences against virioplankton sequences revealed preferential matching of replication proteins, nucleic acid binding proteins, and viral structural proteins. Positive selection pressure for effective viral defense is one parsimonious explanation for these observations. CRISPR spacers from virioplankton metagenomes preferentially matched methyltransferase and phage integrase genes within virioplankton sequences. These virioplankton CRISPR spacers may assist infected host cells in defending against competing phage. Analyses also revealed that half of the spacer-matched viral genes were unknown, some genes matched several spacers, and some spacers matched multiple genes, a many-to-many relationship. Thus, CRISPR spacer matching may be an evolutionary algorithm, agnostically identifying those genes under stringent selection pressure for sustaining viral infection and lysis. Investigating this subset of viral genes could reveal those genetic mechanisms essential to virus-host interactions and provide new technologies for optimizing CRISPR defense in beneficial microbes.

TheZetaproteobacteriaare a class of bacteria typically associated with marine Fe oxidizing environments. First discovered in the hydrothermal vents at Loihi Seamount, Hawaii, they have become model organisms for marine microbial Fe oxidation. In addition to deep sea and shallow hydrothermal vents,Zetaproteobacteriaare found in coastal sediments, other marine subsurface environments, steel corrosion biofilms, as well as saline terrestrial aquifers and springs. Isolates from a range of environments all grow by Fe oxidation. Their success lies partly in their microaerophily, which enables them to compete with abiotic Fe oxidation at the low O2concentrations common to Fe(II)-rich oxic/anoxic transition zones. Also,Zetaproteobacteriamake a variety of biomineral morphologies as a repository for Fe(III) waste, and as attachment structures. To determine the known diversity of theZetaproteobacteria, we have used 16S rRNA gene sequences to define 59 operational taxonomic units (OTUs), at 97% similarity. While someZetaproteobacteriataxa appear to be cosmopolitan, various habitats enrich for different sets ofZetaproteobacteria. OTU networks show that certainZetaproteobacteriaco-exist, sharing compatible niches. These niches may correspond with adaptations to O2, H2, and nitrate availability, based on genomic analyses. Also, a putative Fe oxidation gene has been found in diverseZetaproteobacteriataxa, suggesting that theZetaproteobacteriaevolved as specialists in Fe oxidation. In all, culture, genomic, and environmental studies suggest thatZetaproteobacteriaare widespread, and therefore have a broad influence on marine and saline terrestrial Fe cycling.

Like many taxa, the Zetaproteobacteria lack well-defined taxonomic divisions, making it difficult to compare them between studies. We designed ZetaHunter to reproducibly assign 16S rRNA gene sequences to previously described operational taxonomic units (OTUs) based on a curated database. While ZetaHunter can use any given database, we included a curated classification of publicly available Zetaproteobacteria.

Like many taxa, the Zetaproteobacteria lack well-defined taxonomic divisions, making it difficult to compare them between studies. We designed ZetaHunter to reproducibly assign 16S rRNA gene sequences to previously described operational taxonomic units (OTUs) based on a curated database., Like many taxa, the Zetaproteobacteria lack well-defined taxonomic divisions, making it difficult to compare them between studies. We designed ZetaHunter to reproducibly assign 16S rRNA gene sequences to previously described operational taxonomic units (OTUs) based on a curated database. While ZetaHunter can use any given database, we included a curated classification of publicly available Zetaproteobacteria.

Like many taxa, the Zetaproteobacteria lack well-defined taxonomic divisions, 32 making it difficult to compare between studies. We designed ZetaHunter to reproducibly 33 assign 16S rRNA gene sequences to previously-described OTUs based on a curated 34 database. While ZetaHunter can use any given database, we include a curated 35 classification of publically-available Zetaproteobacteria.

Background Venous thromboembolic events result in significant morbidity, mortality, and costly therapeutic interventions. As medical resource allocation strategies are becoming more pervasive, appropriate risk stratification and prophylactic regimens are essential. Previous studies have shown a decreased incidence of perioperative venous thromboembolism in the chronic spinal cord injury population. The question remains of whether chronic spinal cord injury is protective against venous thromboembolism. Methods A retrospective review of all cases involving chronic spinal cord injury patients who underwent plastic and reconstructive surgery operations (n = 424) and general surgery patients (n = 777) with a primary outcome of deep venous thrombosis or pulmonary embolism within 90 days of surgery was performed. Results The incidence of postoperative deep venous thrombosis in the control and spinal cord injury groups was 1.7 percent and 0.2 percent, respectively (p = 0.027). However, such significance was not observed with regard to postoperative pulmonary embolism incidence (p = 0.070). Collectively, the incidence of postoperative venous thromboembolism-specifically, deep venous thrombosis or pulmonary embolism-was significantly greater in the general surgery population (p = 0.014). A nearly 10-fold increased risk of venous thromboembolism was seen among the control group (1.9 percent versus 0.2 percent) despite administration of optimal prophylaxis. Conclusions This study demonstrates a profoundly low incidence of venous thromboembolism among chronic spinal cord injury patients compared with general surgery patients. Future efforts to elucidate how chronic spinal cord injury confers a protective mechanism may potentially influence the evolution of venous thromboembolism prevention guidelines, and spark the development of alternative prophylactic agents or customized application of prevention efforts.

The authors present a new technique of alteration of the acellular dermal matrix through strategically placed fenestrations, improving the reconstructive experience and overall cosmetic outcome. The authors present a retrospective chart review following two surgeons' experience at the University of California, Irvine, Department of Plastic Surgery using surgeon-designed fenestrated acellular dermal matrices in two-stage tissue expander breast reconstruction. The authors found that this leads to improved intraoperative fill volume, decreased number of postoperative expansions, increased expansion rate with subjectively less pain, decreased time to full expansion, and subjectively improved cosmetic outcome.Therapeutic, III.

Background & Aims The kinase Akt mediates resistance of pancreatic cancer (PaCa) cells to death and is constitutively active (phosphorylated) in cancer cells. Whereas the kinases that activate Akt are well characterized, less is known about phosphatases that dephosporylate and thereby inactivate it. We investigated regulation of Akt activity and cell death by the phosphatases PHLPP1 and PHLPP2 in PaCa cells, mouse models of PaCa, and human pancreatic ductal adenocarcinoma (PDAC). Methods We measured the effects of PHLPP overexpression or knockdown with small interfering RNAs on Akt activation and cell death. We examined regulation of PHLPPs by growth factors and reactive oxygen species, as well as associations between PHLPPs and tumorigenesis. Results PHLPP overexpression inactivated Akt, whereas PHLPP knockdown increased phosphorylation of Akt in PaCa cells. Levels of PHLPPs were greatly reduced in human PDAC and in mouse genetic and xenograft models of PaCa. PHLPP activities in PaCa cells were down-regulated by growth factors and Nox4 reduced nicotinamide adenine dinucleotide phosphate oxidase. PHLPP1 selectively dephosphorylated Akt2, whereas PHLPP2 selectively dephosphorylated Akt1. Akt2, but not Akt1, was up-regulated in PDAC, and Akt2 levels correlated with mortality. Consistent with these results, high levels of PHLPP1, which dephosphorylates Akt2 (but not PHLPP2, which dephosphorylates Akt1), correlated with longer survival times of patients with PDAC. In mice, xenograft tumors derived from PaCa cells that overexpress PHLPP1 (but not PHLPP2) had inactivated Akt, greater extent of apoptosis, and smaller size. Conclusions PHLPP1 has tumor suppressive activity and might represent a therapeutic or diagnostic tool for PDAC.

Background & Aims: Autophagy plays a dual role in cancer development. Recent data indicate that autophagy is oncosuppressive and impaired autophagy is emerging as the critical pro-onco “hallmark” of cancer cells. On the other hand, autophagy is a prosurvival mechanism, and its inhibition may increase cancer cell death and thus be beneficial. Beclin-1 plays a key role in mediating autophagy; its interaction with class III PI3K hVPS34 was shown to be necessary for the autophagosome formation in eukaryotic cells and Beclin-1 knockdown promotes tumorigenesis. Here we investigate the role of Beclin-1 in autophagy and apoptosis in pancreatic cancer cells. Methods: Pancreatic cancer (PaCa) cells PANC-1, and CAPAN-2 were subjected to amino-acid (AA) depletion or hypoxia, strong autophagy activators. Measuring autophagic marker LC3-II with western blot or with immunofluorescence assessed the number of autophagic vacuoles. Autophagy induction was measured in cells pretreated with NH4Cl or bafilomycin to block autophagy progression. Fusion of autophagosomes with lysosomes was assessed by co-localization of lysosomal marker LAMP-1 with LC3; the efficiency of autophagic flux by measuring the levels of p62, which is degraded through autophagy; apoptosis by DNA fragmentation, and caspase-3 activity. Results: AA depletion and hypoxia increased LC3-II both in the presence and absence of NH4Cl, indicating autophagy induction. AA depletion and hypoxia decreased p62 level, indicating stimulation of autophagic degradation. In cells treated with or without AA depletion or hypoxia Beclin-1 knockdown had no effect on either autophagic vacuole formation or p62 degradation. Similarly, the inhibition of Beclin-1 partner, hVPS 34 with siRNA or with PI3K inhibitor 3-methyladenine (3MA), decreased neither autophagy induction nor autophagic degradation. Finally, silencing of both Beclin-1 and its downstream mediator, Atg5 did not affect autophagy induction by AA depletion or hypoxia. All these data indicate that autophagy in PaCa cells is mediated through Beclin-1, Atg5, hVPS 34 -independent pathway. Of note, Beclin-1 knockdown increased co-localization of LC3 with LAMP-1 and p62 levels indicating that autophagy progression is delayed in the absence of Beclin-1. AA depletion and hypoxia moderately (∼by 30%) increased apoptosis in PaCa cells. Silencing of Beclin-1, hVPS 34, or Atg5 had no effect on apoptosis, in basal conditions as well as well as in cells subjected to AA depletion or hypoxia. Differently, 3MA stimulated apoptosis through Beclin-1-independent mechanism. Conclusions: In pancreatic cancer cells AA depletion and hypoxia activate autophagy through non-canonical pathway, which does not involve Beclin-1. Silencing of the key mediators of canonical autophagy, Beclin-1, Atg5 and hVPS34 had no effect on autophagy and apoptosis, whereas 3MA stimulated apoptosis through autophagy-independent pathway. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3775. doi:10.1158/1538-7445.AM2011-3775

Background Since 1982, specific serotypes of Shiga toxin-producing Escherichia coli (STEC) have been recognized as significant foodborne pathogens acquired from contaminated beef and, more recently, other food products. Cattle are the major reservoir hosts of these organisms, and while there have been advancements in food safety practices and industry standards, STEC still remains prevalent within beef cattle operations with cattle hides implicated as major sources of carcass contamination. To investigate whether the composition of hide-specific microbial communities are associated with STEC prevalence, 16S ribosomal RNA (rRNA) bacterial community profiles were obtained from hide and fecal samples collected from a large commercial feedlot over a 3-month period. These community data were examined amidst an extensive collection of prevalence data on a subgroup of STEC that cause illness in humans, referred to as enterohemorrhagic E. coli (EHEC). Fecal 16S rRNA gene OTUs (operational taxonomic units) were subtracted from the OTUs found within each hide 16S rRNA amplicon library to identify hide-specific bacterial populations. Results Comparative analysis of alpha diversity revealed a significant correlation between low bacterial diversity and samples positive for the presence of E. coli O157:H7 and/or the non-O157 groups: O26, O111, O103, O121, O45, and O145. This trend occurred regardless of diversity metric or fecal OTU presence. The number of EHEC serogroups present in the samples had a compounding effect on the inverse relationship between pathogen presence and bacterial diversity. Beta diversity data showed differences in bacterial community composition between samples containing O157 and non-O157 populations, with certain OTUs demonstrating significant changes in relative abundance. Conclusions The cumulative prevalence of the targeted EHEC serogroups was correlated with low bacterial community diversity on pre-harvest cattle hides. Understanding the relationship between indigenous hide bacterial communities and populations may provide strategies to limit EHEC in cattle and provide biomarkers for EHEC risk assessment. Electronic supplementary material The online version of this article (doi:10.1186/s40168-016-0155-4) contains supplementary material, which is available to authorized users.