Biology subjects

Jones, S. H.

Publications and source records attributed to Jones, S. H..

3 recordsLinked to original sources

bioRxiv2018

Assessment of the petroleum hydrocarbon biodegradation potential of the sediment microbial community from an urban fringing tidal marsh of Northern New England.

We assessed the impact of dodecane, n- hexane and gasoline on the microbial diversity of chronically polluted fringing tidal marsh sediment from the Great Bay Estuary of New Hampshire. Dilution cultures containing saturated alkane concentrations were sampled at zero, one and 10 days, and alkB and cyp153A1 alkane hydroxylase gene libraries and 16S rRNA sequences were analyzed. The initial sediment had the most diverse alkane hydroxylase sequences and phylogenetic composition whereas treated sediments became less functionally and phylogenetically diverse with alkane substrates apparently enriching a few dominant taxa. All 1-and 10-day samples were dominated by Pseudomonas- type alkane hydroxylase sequences except in dodecane treatments where primarily Rhodococcus--type alkane hydroxylases were detected. 16S rRNA profiling revealed that the Gammaproteobacteria, particularly Pseudomonas, dominated all one day samples, especially the n- hexane and gasoline treatments (63.2 and 47.2% respectively) and the 10-day n- hexane treatment (which contained 60.8% Pseudomonas and 18.6%Marinobacter). In contrast, the 10 days of dodecane treatment enriched for Actinobacteria (26.2% Rhodococcus and 32.4%Mycobacterium) and gasoline treatment enriched for Firmicutes (29.7%; mainly Bacillus, Lysinibacillus and Rumelibacillus). Our data indicate that fringing tidal marshes contain microbial communities with alkane-degrading abilities similar to larger meadow marshes, and support the hypothesis that alkane exposure reduces the functional and phylogenetic diversity of microbial communities in an alkane-specific manner. Further research to evaluate the ability of such fringing marsh communities to rebound to pre-pollutant diversity levels should be conducted to better assess the threat of petroleum to these habitats.

microbiology↗

bioRxiv2017

Bacterial community profiles and Vibrio parahaemolyticus abundance in individual oysters and their association with estuarine ecology

Oysters naturally harbor the human gastric pathogen Vibrio parahaemolyticus, but the nature of this association is unknown. Because microbial interactions could influence the accumulation of V. parahaemolyticus in oysters, we investigated the composition of the microbiome in water and oysters at two ecologically unique sites in the Great Bay Estuary, New Hampshire using 16s rRNA profiling. We then evaluated correlations between bacteria inhabiting the oyster with V. parahaemolyticus abundance quantified using a most probable number (MPN) analysis. Even though oysters filter-feed, their microbiomes were not a direct snapshot of the bacterial community in overlaying water, suggesting they selectively accumulate some bacterial phyla. The microbiome of individual oysters harvested more centrally in the bay were relatively more similar to each other and had fewer unique phylotypes, but overall more taxonomic and metabolic diversity, than the microbiomes from tributary-harvested oysters that were individually more variable with lower taxonomic and metabolic diversity. Oysters harvested from the same location varied in V. parahaemolyticus abundance, with the highest abundance oysters collected from one location. This study, which to our knowledge is the first of its kind to evaluate associations of V. parahaemolyticus abundance with members of individual oyster microbiomes, implies that sufficient sampling and depth of sequencing may reveal microbiome members that could impact V. parahaemolyticus abundance.

microbiology↗

bioRxiv2017

Parallel evolution of two clades of a major Atlantic endemic Vibrio parahaemolyticus pathogen lineage by independent acquisition of related pathogenicity islands

Shellfish-transmitted Vibrio parahaemolyticus infections have recently increased from locations with historically low disease incidence, such as the Northeast United States (US). This change coincided with a bacterial population shift towards human pathogenic variants occurring in part through the introduction of several Pacific native lineages (ST36, ST43 and ST636) to near-shore areas off the Atlantic coast of the Northeast US. Concomitantly, ST631 emerged as a major endemic pathogen. Phylogenetic trees of clinical and environmental isolates indicated that two clades diverged from a common ST631 ancestor, and in each of these clades, a human pathogenic variant evolved independently through acquisition of distinct Vibrio pathogenicity islands (VPaI). These VPaI differ from each other and bear little resemblance to hemolysin-containing VPaI from isolates of the pandemic clonal complex. Clade I ST631 isolates either harbored no hemolysins, or contained a chromosome I-inserted island we call VPaI{beta} that encodes a type three secretion system (T3SS2{beta}) typical of Trh hemolysin-producers. The more clinically prevalent and clonal ST631 clade II had an island we call VPaI{gamma} that encodes both tdh and trh and that was inserted in chromosome II. VPaI{gamma} was derived from VPaI{beta} but with some additional acquired elements in common with VPaI carried by pandemic isolates, exemplifying the mosaic nature of pathogenicity islands. Genomics comparisons and amplicon assays identified VPaI{gamma}-type islands containing tdh inserted adjacent to the ure cluster in the three introduced Pacific and most other emergent lineages. that collectively cause 67% of Northeast US infections as of 2016.\n\nIMPORTANCEThe availability of three different hemolysin genotypes in the ST631 lineage provided a unique opportunity to employ genome comparisons to further our understanding of the processes underlying pathogen evolution. The fact that two different pathogenic clades arose in parallel from the same potentially benign lineage by independent VPaI acquisition is surprising considering the historically low prevalence of community members harboring VPaI in waters along the Northeast US Coast that could serve as the source of this material. This illustrates a possible predisposition of some lineages to not only acquire foreign DNA but also to become human pathogens. Whereas the underlying cause for the expansion of V. parahaemolyticus lineages harboring VPaI{gamma} along the US Atlantic coast and spread of this element to multiple lineages that underlies disease emergence is not known, this work underscores the need to define the environment factors that favor bacteria harboring VPaI in locations of emergent disease.

evolutionary biology↗