Recent work has demonstrated that the diversity of skin-associated bacterial communities is far higher than previously recognized, with a high degree of interindividual variability in the composition of bacterial communities. Given that skin bacterial communities are personalized, we hypothesized that we could use the residual skin bacteria left on objects for forensic identification, matching the bacteria on the object to the skin-associated bacteria of the individual who touched the object. Here we describe a series of studies demonstrating the validity of this approach. We show that skinassociated bacteria can be readily recovered from surfaces (including single computer keys and computer mice) and that the structure of these communities can be used to differentiate objects handled by different individuals, even if those objects have been left untouched for up to 2 weeks at room temperature. Furthermore, we demonstrate that we can use a high-throughput pyrosequencing-based approach to quantitatively compare the bacterial communities on objects and skin to match the object to the individual with a high degree of certainty. Although additional work is needed to further establish the utility of this approach, this series of studies introduces a forensics approach that could eventually be used to independently evaluate results obtained using more traditional forensic practices.bacterial forensics | human microbiome | pyrosequencing | skin microbiology | microbial ecology T he human skin surface harbors large numbers of bacteria that can be readily dislodged and transferred to surfaces upon touching, hence the importance of proper hand hygiene by health care practitioners (1, 2). These skin bacteria may persist on touched surfaces for prolonged periods because many are highly resistant to environmental stresses, including moisture, temperature, and UV radiation (3, 4). Therefore, we likely leave a persistent "trail" of skin-associated bacteria on the surfaces and objects that we touch during our daily activities.Recent work has demonstrated that our skin-associated bacterial communities are surprisingly diverse, with a high degree of interindividual variability in the composition of bacterial communities at a particular skin location (5-9). For example, only 13% of the bacterial phylotypes on the palm surface are shared between any two individuals (8), and a similar level of interpersonal differentiation is observed at other skin locations (5, 9). In addition, skin bacterial communities are relatively stable over time: palm surface bacterial communities recover within hours after hand washing (8); and, on average, interpersonal variation in community composition exceeds temporal variation within people, even when individuals are sampled many months apart (5, 9). Given that individuals appear to harbor personally unique, temporally stable, and transferable skin-associated bacterial communities, we hypothesized that we could use these bacteria as "fingerprints" for forensic identification.To demonstrate that we can ...

Storage conditions are considered to be a critical component of DNA-based microbial community analysis methods. However, whether differences in short-term sample storage conditions impact the assessment of bacterial community composition and diversity demands systematic and quantitative assessment. Therefore, we used barcoded pyrosequencing of bacterial 16S rRNA genes to survey communities, harvested from a variety of habitats (soil, human gut (feces) and human skin) and subsequently stored at 20°, 4°, −20°, and −80°C for 3 and 14 days. Our results indicate that the phylogenetic structure and diversity of communities in individual samples was not significantly influenced by storage temperature or duration of storage. Likewise, the relative abundances of most taxa were largely unaffected by temperature even after 14 days of storage. Our results indicate that environmental factors and biases in molecular techniques likely impart greater amounts of variation to microbial communities than do differences in short-term storage conditions, including storage for up to two weeks at room temperature. These results suggest that many samples collected and stored under field conditions without refrigeration may be useful for microbial community analyses.

It is time to redefine VAP in trauma patients based on the effect of rib fractures, pulmonary contusions, and failed prehospital intubations. The Centers for Disease Control and Prevention definition of VAP needs to be modified to reflect the effect of trauma factors in the etiology of trauma-associated pneumonia.

Neoadjuvant ipilimumab + nivolumab (Ipi+Nivo) and nivolumab + chemotherapy (Nivo+CT) induce greater pathologic response rates than CT alone in patients with operable non-small cell lung cancer (NSCLC). The impact of adding ipilimumab to neoadjuvant Nivo+CT is unknown. Here we report the results and correlates of two arms of the phase 2 platform NEOSTAR trial testing neoadjuvant Nivo+CT and Ipi+Nivo+CT with major pathologic response (MPR) as the primary endpoint. MPR rates were 32.1% (7/22, 80% confidence interval (CI) 18.7–43.1%) in the Nivo+CT arm and 50% (11/22, 80% CI 34.6–61.1%) in the Ipi+Nivo+CT arm; the primary endpoint was met in both arms. In patients without known tumor EGFR/ALK alterations, MPR rates were 41.2% (7/17) and 62.5% (10/16) in the Nivo+CT and Ipi+Nivo+CT groups, respectively. No new safety signals were observed in either arm. Single-cell sequencing and multi-platform immune profiling (exploratory endpoints) underscored immune cell populations and phenotypes, including effector memory CD8+ T, B and myeloid cells and markers of tertiary lymphoid structures, that were preferentially increased in the Ipi+Nivo+CT cohort. Baseline fecal microbiota in patients with MPR were enriched with beneficial taxa, such as Akkermansia, and displayed reduced abundance of pro-inflammatory and pathogenic microbes. Neoadjuvant Ipi+Nivo+CT enhances pathologic responses and warrants further study in operable NSCLC. (ClinicalTrials.gov registration: NCT03158129.)

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