Specific Microbial Taxa Research Articles

Antibiotic resistome profile based on metagenomics in raw surface drinking water source and the influence of environmental factor: A case study in Huaihe River Basin, China

The contamination with antibiotic resistance genes (ARGs) in raw drinking water source may pose a direct threat to human health. In this study, metagenomics sequencing and analysis were applied to investigate the ARG pattern in 12 drinking water sources in upper and middle reach of Huaihe River Basin, China. Based on the redundant analysis and multi-linear regression model, location, specific microbial taxa, number of livestock and health facilities significantly influenced the ARG profile in drinking water sources. Besides the cluster effect of ARG in samples from plain and bedrock mountain areas, the samples from fracture aquifer areas also showed a distinctive biogeographic pattern with that from porous aquifer areas. Putative ARGs host Opitutus and Flavobacterium were the enriched biomarkers in plain and fracture aquifer area respectively, which mainly carried bacitracin, multidrug, beta-lactam and tetracycline ARGs. This result illuminated that both natural background and anthropogenic activities in the watershed influenced the ARG profile in natural freshwater system significantly. The low MGEs abundance and absence of pathogen revealed a low ARG dissemination risk in sampled drinking water sources, while Polynucleobacter was an abundant ARGs host and was significantly related to the ARG profile, which indicated that specific bacteria was responsible for ARGs propagation and accumulation in surface freshwater system. Further researches are needed to assess human exposure to raw drinking water source and the potential risk, as well as the species interaction in microbial community and its impact on ARG propagation under oligotrophic condition.

Chemical nature of soil organic carbon under different long-term fertilization regimes is coupled with changes in the bacterial community composition in a Calcaric Fluvisol

Fertilization is an important factor influencing the chemical structure of soil organic carbon (SOC) and soil microbial communities; however, whether any connection exists between the two under different fertilization regimes remains unclear. Soils from a 27-year field experiment were used to explore potential associations between SOC functional groups and specific bacterial taxa, using quantitative multiple cross-polarization magic-angle spinning 13C nuclear magnetic resonance and 16S rRNA gene sequencing. Treatments included balanced fertilization with organic materials (OM) and with nitrogen (N), phosphorus (P), and potassium (K) mineral fertilizers (NPK); unbalanced fertilization without one of the major elements (NP, PK, or NK); and an unamended control. These treatments were divided into four distinct groups, namely OM, NPK, NP plus PK, and NK plus control, according to their bacterial community composition and SOC chemical structure. Soil total P, available P, and SOC contents were the major determinants of bacterial community composition after long-term fertilization. Compared to NPK, the OM treatment generated a higher aromatic C–O and OCH3 and lower alkyl C and OCH abundance, which were associated with the enhanced abundance of members of the Acidobacteria subgroups 6 and 5, Cytophagaceae, Chitinophagaceae, and Bacillus sp.; NP plus PK treatments resulted in a higher OCH and lower aromatic C–C abundance, which showed a close association with the enrichment of unclassified Chloracidobacteria, Syntrophobacteraceae, and Anaerolineae and depletion of Bacillales; and NK plus control treatments resulted in a higher abundance of aromatic C–C, which was associated with the enhanced abundance of Bacillales. Our results indicate that different fertilization regimes changed the SOC chemical structure and bacterial community composition in different patterns. The results also suggest that fertilization-induced variations in SOC chemical structure were strongly associated with shifts in specific microbial taxa which, in turn, may be affected by changes in soil properties.

Exploring abundance, diversity and variation of a widespread antibiotic resistance gene in wastewater treatment plants

An updated sul1 gene sequence database was constructed and new degenerate primers were designed to better investigate the abundance, diversity, and variation of a ubiquitous antibiotic resistance gene, sul1, with PCR-based methods in activated sludge from wastewater treatment plants (WWTPs). The newly designed degenerate primers showed high specificity and higher coverage in both in-silico evaluations and activated sludge samples compared to previous sul1 primers. Using the new primers, the abundance and diversity of sul1 gene, together with 16S rRNA gene, in activated sludge from five WWTPs in summer and winter were determined by quantitative PCR and MiSeq sequencing. The sul1 gene was found to be prevalent and displayed a comparable abundance (0.081 copies per bacterial cell in average) to the total bacteria across all samples. However, compared to the significant seasonal and geographical divergences in the quantity and diversity of bacterial communities in WWTPs, there were no significant seasonal or geographical variations of representative clusters of sul1 gene in most cases. Additionally, the representative sul1 clusters showed fairly close phylogeny and there was no obvious correlation between sul1 gene and the dominant bacterial genera, as well as the int1 gene, suggesting that bacterial hosts of sul1 gene is not stable, the sul1 gene may be carried by mobile genetic elements, sometimes integrated with class 1 integrons and sometimes not. Thus mobile genetic elements likely play a greater role than specific microbial taxa in determining the composition of sul1 gene in WWTPs.

Restoration of short chain fatty acid and bile acid metabolism following fecal microbiota transplantation in patients with recurrent Clostridium difficile infection

A significant proportion of individuals develop recurrent Clostridium difficile infection (CDI) following initial disease. Fecal microbiota transplantation (FMT), a highly effective treatment method for recurrent CDI, has been demonstrated to induce microbiota recovery. One of the proposed functions associated with restoration of colonization resistance against C. difficile has been recovery of bile acid metabolism. In this study, we aimed to assess recovery of short chain fatty acids (SCFAs) in addition to bile acids alongside microbial community structure in six patients with recurrent CDI following treatment with FMT over time. Using 16S rRNA gene-based sequencing, we observed marked similarity of the microbiota between recipients following FMT (n = 6, sampling up to 6 months post-FMT) and their respective donors. Sustained increases in the levels of the SCFAs butyrate, acetate, and propionate were observed post-FMT, and variable recovery over time was observed in the secondary bile acids deoxycholate and lithocholate. To correlate these changes with specific microbial taxa at an individual level, we applied a generalized estimating equation approach to model metabolite concentrations with the presence of specific members of the microbiota. Metabolites that increased following FMT were associated with bacteria classified within the Lachnospiraceae, Ruminococcaceae, and unclassified Clostridiales families. In contrast, members of these taxa were inversely associated with primary bile acids. The longitudinal aspect of this study allowed us to characterize individualized patterns of recovery, revealing variability between and within patients following FMT.

Assembly and ecological function of the root microbiome across angiosperm plant species

Across plants and animals, host-associated microbial communities play fundamental roles in host nutrition, development, and immunity. The factors that shape host-microbiome interactions are poorly understood, yet essential for understanding the evolution and ecology of these symbioses. Plant roots assemble two distinct microbial compartments from surrounding soil: the rhizosphere (microbes surrounding roots) and the endosphere (microbes within roots). Root-associated microbes were key for the evolution of land plants and underlie fundamental ecosystem processes. However, it is largely unknown how plant evolution has shaped root microbial communities, and in turn, how these microbes affect plant ecology, such as the ability to mitigate biotic and abiotic stressors. Here we show that variation among 30 angiosperm species, which have diverged for up to 140 million years, affects root bacterial diversity and composition. Greater similarity in root microbiomes between hosts leads to negative effects on plant performance through soil feedback, with specific microbial taxa in the endosphere and rhizosphere potentially affecting competitive interactions among plant species. Drought also shifts the composition of root microbiomes, most notably by increasing the relative abundance of the Actinobacteria. However, this drought response varies across host plant species, and host-specific changes in the relative abundance of endosphere Streptomyces are associated with host drought tolerance. Our results emphasize the causes of variation in root microbiomes and their ecological importance for plant performance in response to biotic and abiotic stressors.

Effects of humic acid on pentachlorophenol biodegrading microorganisms elucidated by stable isotope probing and high‐throughput sequencing approaches

Humic substances (HSs) are ubiquitous in soil and can be reversibly oxidized and reduced by acting as redox mediators. They participate in microbial metabolism and directly affect the biodegradation of organic pollutants. However, the effects of HSs on specific microbial taxa that are responsible for the degradation of organic pollutants remain unclear. In this research, the effects of humic acids (HAs), extracted from three types of soil, forest (CBHA), paddy (PSHA) and peat (YNHA) on the microbial community involved in anaerobic mineralization of pentachlorophenol (PCP) were investigated with high‐throughput sequencing and stable isotope probing (SIP) approaches. The results showed that all HA samples accelerated the biotransformation processes of PCP; the largest rate was obtained with YNHA. Illumina sequencing revealed that Desulfovibrio and Clostridium were the dominant functional bacteria for the dechlorination of PCP. During the subsequent PCP degradation and mineralization processes, HAs affected the diversity and abundance of microbial communities, and several taxa were enriched in the 13C‐heavy fractions compared with 12C‐heavy fractions. In the absence of HA, Methanobacterium and Spartobacteria showed a significant increase in 13C‐heavy fractions. Methanosarcina and OP11 were the dominant PCP degraders in microcosms when amended with CBHA, whereas Burkholderia and Methanobacterium were the key PCP degraders in PSHA‐ and YNHA‐amended experimental microcosms. These results improve our knowledge of the diversity and ubiquitous nature of HS‐utilizing microorganisms involved in PCP degradation, providing scientific support for the development of in situ bioremediation technologies for HS‐rich soil contaminated by PCP.Highlights All humic acids facilitated biodegradation of pentachlorophenol. The greater the carbon content of HA, the greater was the rate of dechlorination. Clostridium and Desulfovibrio dominated PCP dechlorination. SIP suggested that Methanobacterium, Methanosaricina, OP11, Spartobactria and Burholderia acquired PCP‐derived carbon.

Impact of dietary induced precocious gut maturation on cecal microbiota and its relation to the blood-brain barrier during the postnatal period in rats.

Precocious maturation of the gastrointestinal barrier (GIB) in newborn mammals can be induced by dietary provocation, but how this affects the gut microbiota and the gut-brain axis remains unknown. The objective of this study was to investigate effects of induced GIB maturation on gut microbiota composition and blood-brain barrier (BBB) permeability. Suckling rats were studied at 72h after gavage with phytohemagglutinin (PHA) or microbial protease (PT) to induce maturation of GIB. For comparison, untreated suckling and weaned rats were included (n=10). Human serum albumin (HSA) was administered orally and analyzed in blood to assess permeability of the GIB, while intraperitoneally injected bovine serum albumin (BSA) was measured in the brain tissue for BBB permeability. The cecal microbial composition, plasma lipopolysaccharide-binding protein (LBP) levels and short-chain fatty acids in serum and brain were analyzed. Cessation of HSA passage to blood after PHA or PT treatment was similar to that seen in weaned rats. Interestingly, concomitant increases in cecal Bacteroidetes and plasma LBP levels were observed after both PHA and PT treatments. The BBB passage of BSA was surprisingly elevated after weaning, coinciding with lower plasma LBP levels and specific microbial taxa and increased acetate uptake into the brain. This study provides evidence that the gut microbiota alteration following induced precocious GIB maturation may induce low-grade systemic inflammation and alter SCFAs utilization in the brain which may also play a potential role in GIB-BBB dysfunction disorders in neonates.

Pole-to-Pole Connections: Similarities between Arctic and Antarctic Microbiomes and Their Vulnerability to Environmental Change

The global biogeography of microorganisms remains poorly resolved, which limits the current understanding of microbial resilience toward environmental changes. Using high-throughput 16S rRNA gene amplicon sequencing, we characterized the microbial diversity of terrestrial and lacustrine biofilms from the Arctic, Antarctic and temperate regions. Our analyses suggest that bacterial community compositions at the poles are more similar to each other than they are to geographically closer temperate habitats, with 32% of all operational taxonomic units (OTUs) co-occurring in both polar regions. While specific microbial taxa were confined to distinct regions, representing potentially endemic populations, the percentage of cosmopolitan taxa was higher in Arctic (43%) than in Antarctic samples (36%). The overlap in polar microbial OTUs may be explained by natural or anthropogenically-mediated dispersal in combination with environmental filtering. Current and future changing environmental conditions may enhance microbial invasion, establishment of cosmopolitan genotypes and loss of endemic taxa.

Metal worker’s lung: spatial association with Mycobacterium avium

BackgroundOutbreaks of hypersensitivity pneumonitis (HP) are not uncommon in workplaces where metal working fluid (MWF) is used to facilitate metal turning. Inhalation of microbe-contaminated MWF has been assumed to be...

Group B Streptococcus and the Vaginal Microbiota.

Streptococcus agalactiae (group B Streptococcus [GBS]) is an important neonatal pathogen and emerging cause of disease in adults. The major risk factor for neonatal disease is maternal vaginal colonization. However, little is known about the relationship between GBS and vaginal microbiota. Vaginal lavage samples from nonpregnant women were tested for GBS, and amplicon-based sequencing targeting the 16S ribosomal RNA V3-V4 region was performed. Four hundred twenty-eight of 432 samples met the high-quality read threshold. There was no relationship between GBS carriage and demographic characteristics, α-diversity, or overall vaginal microbiota community state type (CST). Within the non-Lactobacillus-dominant CST IV, GBS positive status was significantly more prevalent in CST IV-A than CST IV-B. Significant clustering by GBS status was noted on principal coordinates analysis, and 18 individual taxa were found to be significantly associated with GBS carriage by linear discriminant analysis. After adjusting for race/ethnicity, 4 taxa were positively associated with GBS, and 6 were negatively associated. Vaginal microbiota CST and α-diversity are not related to GBS status. However, specific microbial taxa are associated with colonization of this important human pathogen, highlighting a potential role for the microbiota in promotion or inhibition of GBS colonization.

Alterations of Gut Microbiome in Rheumatoid Arthritis

Purpose: Rheumatoid arthritis (RA) is a chronic inflammatory joint disease, which can cause cartilage and bone damage as well as disability. Recent studies have indicated that the pathogenesis of RA requires the interaction between genetic and environmental factors, such as gut microbiome. However, current evidence for the alterations of gut microbiome in RA is still limited. Thus, our study aimed to analyze the fecal samples from a cohort patient with RA and to identify the associated alterations in gut microbiome when compared to healthy controls. Methods: Fecal samples were obtained from treatment-naïve RA patients (n=50) and healthy controls (n=50). High-quality 16S rDNA V3–V4 sequences were extracted from fecal samples and further sequenced on a 454 Genome Sequencer platform for bioinformatics analysis, resulting in operational taxonomic units (OTUs) related to gut microbiota and phylogenetic tree. Clinical parameters of RA were correlated with specific microbial taxa by Correlation analysis. Results: A total of 121227 OTUs was clustered at 97 % sequence similarity and assigned taxonomic lineages by comparison with the Ribosomal Database Project database. The OTUs were classified into 35 phylums, 73 classes, 143 orders, 280 families, and 1165 genus. Intriguingly, our data revealed a lower alpha diversity, including richness, evenness and Shannon Index, as well as a lower Firmicutes / Bacteroidetes ratio in the gut microbiome of RA patients when compared with the healthy controls (Figure 1a, b). Moreover, at genus level, our taxonomic analysis identified 288 differentially abundant taxa (P< 0.05) (Figure 2a), among which 6 taxa, including Bacteroides, Parabacteroides, Paraprevotella, Porphyromonadaceae, Phascolarctobacterium and Carnobacterium, were significantly enriched in the gut microbiome of RA patients (Figure 2b, c). Conversely, a series of butyrate-producing taxa such as Faecalibacterium, Roseburia, Subdoligranulum, Ruminococcus and Pseudobutyrivibrio were depleted in RA patients but enriched in healthy controls (Figure 2b, c). Furthermore, we found a negative correlation (P<0.05) between the abundance of butyrate-producing Roseburia and the clinical parameters of disease status and activity such as erythrocyte sedimentation rate and the blood level of rheumatoid factors (IgM) (Figure 3). Conclusions: In the present study, we demonstrated that the composition of the gut microbiome in RA patients differed from that in healthy individuals. Our results revealed a decreased microbial diversity accompanied by altered microbial abundance in the gut microbiome of RA patients, which could be characterized as ‘dysbiosis’ and associated with the disease status and activity. The identified alterations in the gut microbiome might provide an updated overview for postulating molecular understandings and therapeutic strategy in RA.Figure 2. Differentially abundant gut microbiome in RA patients. (a) Data of phylogenetic tree analysis to identify differentially abundant taxa. (b) Percentage of 16S reads of major genus of the gut microbiota of RA patients and controls. (c) Quantification of differentially abundant genus of gut microbiome in RA and Control groups.View Large Image Figure ViewerDownload Hi-res image Download (PPT)Figure 3. Abundance of Roseburia negatively correlated with the clinical parameters of disease activity in RA patients. Upper pannel: Correlation analysis of the 16S reads number of Roseburia and the erythrocyte sedimentation rate (ESR) in RA patients. Lower pannel: Correlation analysis of the 16S reads number of Roseburia and the blood level of rheumatoid factors (IgM) in RA patients. Note: Pearson rank correlation test was performed to determine correlations in the study variables.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Effect of antibiotic pre-treatment and pathogen challenge on the intestinal microbiota in mice.

BackgroundMore than 50 years after the discovery of antibiotics, bacterial infections have decreased substantially; however, antibiotics also may have negative effects such as increasing susceptibility to pathogens. An intact microbiome is an important line of defense against pathogens. We sought to determine the effect of orally administered antibiotics both on susceptibility to pathogens and on impact to the microbiome. We studied Campylobacter jejuni, one of the most common causes of human diarrhea, and Acinetobacter baumannii, which causes wound infections. We examined the effects of antibiotic treatment on the susceptibility of mice to those pathogens as well as their influence on the mouse gut microbiome.ResultsIn C57/BL6 mice models, we explored the effects of pathogen challenge, and antibiotic treatment on the intestinal microbiota. Mice were treated with either ciprofloxacin, penicillin, or water (control) for a 5-day period followed by a 5-day washout period prior to oral challenge with C. jejuni or A. baumannii to assess antibiotic effects on colonization susceptibility. Mice were successfully colonized with C. jejuni more than 118 days, but only transiently with A. baumannii. These challenges did not lead to any major effects on the composition of the gut microbiota. Although antibiotic pre-treatment did not modify pathogen colonization, it affected richness and community structure of the gut microbiome. However, the antibiotic dysbiosis was significantly reduced by pathogen challenge.ConclusionsWe conclude that despite gut microbiota disturbance, susceptibility to gut colonization by these pathogens was unchanged. The major gut microbiome disturbance produced by antibiotic treatment may be reduced by colonization with specific microbial taxa.Electronic supplementary materialThe online version of this article (doi:10.1186/s13099-016-0143-z) contains supplementary material, which is available to authorized users.

The impact of sequence database choice on metaproteomic results in gut microbiota studies.

BackgroundElucidating the role of gut microbiota in physiological and pathological processes has recently emerged as a key research aim in life sciences. In this respect, metaproteomics, the study of the whole protein complement of a microbial community, can provide a unique contribution by revealing which functions are actually being expressed by specific microbial taxa. However, its wide application to gut microbiota research has been hindered by challenges in data analysis, especially related to the choice of the proper sequence databases for protein identification.ResultsHere, we present a systematic investigation of variables concerning database construction and annotation and evaluate their impact on human and mouse gut metaproteomic results. We found that both publicly available and experimental metagenomic databases lead to the identification of unique peptide assortments, suggesting parallel database searches as a mean to gain more complete information. In particular, the contribution of experimental metagenomic databases was revealed to be mandatory when dealing with mouse samples. Moreover, the use of a “merged” database, containing all metagenomic sequences from the population under study, was found to be generally preferable over the use of sample-matched databases. We also observed that taxonomic and functional results are strongly database-dependent, in particular when analyzing the mouse gut microbiota. As a striking example, the Firmicutes/Bacteroidetes ratio varied up to tenfold depending on the database used. Finally, assembling reads into longer contigs provided significant advantages in terms of functional annotation yields.ConclusionsThis study contributes to identify host- and database-specific biases which need to be taken into account in a metaproteomic experiment, providing meaningful insights on how to design gut microbiota studies and to perform metaproteomic data analysis. In particular, the use of multiple databases and annotation tools has to be encouraged, even though this requires appropriate bioinformatic resources.Electronic supplementary materialThe online version of this article (doi:10.1186/s40168-016-0196-8) contains supplementary material, which is available to authorized users.

Abstract P255: Gut Microbiota Diversity and Specific Microbial Genera Associate with Cardiovascular Disease Risk: Findings From the Bogalusa Heart Study

Recent advances in sequencing technology have made it feasible to characterize human gut microbial communities (or microbiota) and examine their associations with disease outcomes, including cardiovascular disease (CVD) related traits. However, there is a paucity of research examining how the human gut microbiome may influence overall CVD risk in population based studies. The objective of the current study was to identify composite measures of microbiota diversity and specific microbial genera that associate with CVD risk among participants of the Bogalusa Heart Study (BHS). The current BHS cohort includes 1,257 participants who have been screened at least two times in childhood and two times in adulthood for CVD risk factors. For the microbiome study, we selected the 55 participants at highest CVD risk and 57 participants at lowest CVD risk using a z-score based data reduction technique, leveraging longitudinal mean measures of systolic BP, low-density lipoprotein cholesterol, and fasting plasma glucose levels. Next generation 16S rRNA sequencing of the V4 hypervariable region was conducted using genomic bacterial DNA extracted from stool samples of the 112 participants. The Wilcoxon rank sum test was used to examine differences in measures of alpha diversity, including observed operational taxonomic units (OTUs) and the Chao1 index, along with specific microbial taxa between CVD risk groups. Permutation multivariate analysis of variance (PERMANOVA) was used to test compositional differences based on unweighted Unifrac distance as a measure of beta diversity. We observed significantly less alpha diversity in those at high versus those at low CVD risk (P=0.04 and 0.02 for observed OTU and Chao1 index measures, respectively). The PERMANOVA test indicated marginal significance of compositional differences between the two groups (P=0.07). In addition, 10 microbial genera significantly differed between high and low CVD risk participants, including Faecalibacterium (P=0.0014), Subdoligranulum (P=0.01), Turicibacter (P=0.01), Rothia (P=0.01), Lachnospira (P=0.01), Haemophilus (P=0.03), Dialister (P=0.03), Bifidobacterium (P=0.03), Oscillibacter (P=0.04), and Megamonas (P=0.05). In summary, we provide empirical evidence of lower microbial enrichment among BHS participants at high versus those at low CVD risk, along with promising findings of differences in specific microbial genera between CVD risk groups.

Taxon-specific responses of soil microbial communities to different soil priming effects induced by addition of plant residues and their biochars

This work investigated changes in priming effects and the taxonomy of soil microbial communities after being amended with plant feedstock and its corresponding biochar. A soil incubation was conducted for 180 days to monitor the mineralization and evolution of soil-primed C after addition of maize and its biochar pyrolysed at 450 °C. Responses of individual microbial taxa were identified and compared using the next-generation sequencing method. Cumulative CO2 showed similar trends but different magnitudes in soil supplied with feedstock and its biochar. Feedstock addition resulted in a positive priming effect of 1999 mg C kg−1 soil (+253.7 %) while biochar gave negative primed C of −872.1 mg C kg−1 soil (−254.3 %). Linear relationships between mineralized material and mineralized soil C were detected. Most priming occurred in the first 15 days, indicating co-metabolism. Differences in priming may be explained by differences in properties of plant material, especially the water-extractable organic C. Predominant phyla were affiliated to Acidobacteria, Actinobacteria, Chloroflexi, Gemmatimonadetes, Firmicutes, Planctomycetes, Proteobacteria, Verrucomicrobia, Ascomycota, Basidiomycota, Blastocladiomycota, Chytridiomycota, Zygomycota, Euryarchaeota, and Thaumarchaeota during decomposition. Cluster analysis resulted in separate phylogenetic grouping of feedstock and biochar. Bacteria (Acidobacteria, Firmicutes, Gemmatimonadetes, Planctomycetes), fungi (Ascomycota), and archaea (Euryarchaeota) were closely correlated to primed soil C (R 2 = −0.98, −0.99, 0.84, 0.81, 0.91, and 0.91, respectively). Quality of plant materials (especially labile C) shifted microbial community (specific microbial taxa) responses, resulting in a distinctive priming intensity, giving a better understanding of the functional role of soil microbial community as an important driver of priming effect.

Importance of soil organic matter for the diversity of microorganisms involved in the degradation of organic pollutants

Many organic pollutants are readily degradable by microorganisms in soil, but the importance of soil organic matter for their transformation by specific microbial taxa is unknown. In this study, sorption and microbial degradation of phenol and 2,4-dichlorophenol (DCP) were characterized in three soil variants, generated by different long-term fertilization regimes. Compared with a non-fertilized control (NIL), a mineral-fertilized NPK variant showed 19% and a farmyard manure treated FYM variant 46% more soil organic carbon (SOC). Phenol sorption declined with overall increasing SOC because of altered affinities to the clay fraction (soil particles <2 mm in diameter). In contrast, DCP sorption correlated positively with particulate soil organic matter (present in the soil particle fractions of 63-2000 μm). Stable isotope probing identified Rhodococcus, Arthrobacter (both Actinobacteria) and Cryptococcus (Basidiomycota) as the main degraders of phenol. Rhodococcus and Cryptococcus were not affected by SOC, but the participation of Arthrobacter declined in NPK and even more in FYM. (14)C-DCP was hardly metabolized in the NIL variant, more efficiently in FYM and most in NPK. In NPK, Burkholderia was the main degrader and in FYM Variovorax. This study demonstrates a strong effect of SOC on the partitioning of organic pollutants to soil particle size fractions and indicates the profound consequences that this process could have for the diversity of bacteria involved in their degradation.

Aerobic Biofilms Grown from Athabasca Watershed Sediments Are Inhibited by Increasing Concentrations of Bituminous Compounds

Sediments from the Athabasca River and its tributaries naturally contain bitumen at various concentrations, but the impacts of this variation on the ecology of the river are unknown. Here, we used controlled rotating biofilm reactors in which we recirculated diluted sediments containing various concentrations of bituminous compounds taken from the Athabasca River and three tributaries. Biofilms exposed to sediments having low and high concentrations of bituminous compounds were compared. The latter were 29% thinner, had a different extracellular polysaccharide composition, 67% less bacterial biomass per μm2, 68% less cyanobacterial biomass per μm2, 64% less algal biomass per μm2, 13% fewer protozoa per cm2, were 21% less productive, and had a 33% reduced content in chlorophyll a per mm2 and a 20% reduction in the expression of photosynthetic genes, but they had a 23% increase in the expression of aromatic hydrocarbon degradation genes. Within the Bacteria, differences in community composition were also observed, with relatively more Alphaproteobacteria and Betaproteobacteria and less Cyanobacteria, Bacteroidetes, and Firmicutes in biofilms exposed to high concentrations of bituminous compounds. Altogether, our results suggest that biofilms that develop in the presence of higher concentrations of bituminous compounds are less productive and have lower biomass, linked to a decrease in the activities and abundance of photosynthetic organisms likely due to inhibitory effects. However, within this general inhibition, some specific microbial taxa and functional genes are stimulated because they are less sensitive to the inhibitory effects of bituminous compounds or can degrade and utilize some bitumen-associated compounds.

585: Distinct vaginal microbiome profiles are associated with host mitochondrial DNA (mtDNA) haplogroup and SNP variants

diac function in a mouse model of IUGR. STUDY DESIGN: Laparotomy was performed on pregnant C57BL/6J mice at gestational day 18 and pups were divided into 3 groups (n 12). Control: Sham operated; IUGR surgically induced by ligation of a branch of the uterine artery; IGF1Treated by intra placental injection of Ad hIGF1 after ligation. Pups were delivered on day 20, cross-fostered to CD1 mice, sorted by gender and at week 8 a western high fat diet introduced. Cross-sectional, 2D and Doppler transthoracic echocardiography was performed at 12 weeks evaluating ejection fraction (EF), fractional shortening (FS) and left ventricular (LV) dimensions. Data were analyzed using ANOVA. RESULTS: IUGR mice demonstrated significantly reduced EF (43.5 8.3 vs 60 5.1vs 59 5.7,p 0.001) and FS (22 4.6 vs 32.2 3.2 vs 31.3 3.7,p 0.001) compared to SHAM that was normalized in the treatment group (FigA). IUGR significantly increased LVID;S (3.6 0.4vs3.1 0.2vs2.9 0.2,p 0.001) as compared to SHAM, restored to normal in IGF1 Treated (FigB). These findings were the same when data was stratified by sex. CONCLUSION: Intra-placental gene transfer of Ad hIGF1 rescues IUGR induced cardiac dysfunction in mice exposed to high fat diet. This supports the concept that in utero therapy may positively impact cardiac remodeling to attenuate adult onset cardiovascular disease under environmental stress. 585 Distinct vaginal microbiome profiles are associated with host mitochondrial DNA (mtDNA) haplogroup and SNP variants Jun Ma, Kjersti Aagaard, Dirk Gevers, Aleksandar Milosavljevic, Penelope Bonnen, Curtis Huttenhouer, James Versalovic Baylor College of Medicine, Molecular and Human Genetics, Houston, TX, The Broad Institute at MIT, Genome Sequencing and Analysis, Boston, MA, Baylor College of Medicine, Pathology and Immunology, Houston, TX, Harvard, School of Public Health, Cambridge, MA, Baylor College of Medicine, Division of Maternal-Fetal Medicine, Departments of ObstetricsG SNP associations were determined wtih PLINK. RESULTS: 173 mtDNA variants (SNP/Indels) from 38 females of diverse racial/ethnic background were identified. Specific taxa (OTU) demonstrated strong association with haplogroups I, W,X and SNP T16311C, but not with other host properties (left panels). The synonymous point mutation T6776C demonstrated strong association with microbial encoded fatty acid metabolism pathways (right panels). CONCLUSION: Several Caucasion haplogroups and mtDNA variants show significant association with specific microbial taxa and metabolic pathways from the posterior fornix of the vagina. We speculate that these findings may partially explain infectious, microbiome and host associations in perinatal disorders.