The Microbial Ecology of Bacterial Vaginosis: A Fine Scale Resolution Metagenomic Analysis

The vaginal microbiota play an important protective role in maintaining the health of women. Disruption of the mutualistic relationship that exists between bacterial communities in the vagina and their hosts can lead to bacterial vaginosis (BV), a condition in which lactic acid producing bacteria are supplanted by a diverse array of strictly anaerobic bacteria. BV has been shown to be an independent risk factor for adverse outcomes including preterm delivery and low infant birth weight, acquisition of sexually transmitted infections and HIV, and development of pelvic inflammatory disease. National surveys indicate the prevalence of BV among U.S. women is 29.2%, and yet, despite considerable effort, the etiology of BV remains unknown. Moreover, there are no broadly effective therapies for the treatment of BV, and reoccurrence is common. In the proposed research we will test the overarching hypothesis that vaginal microbial community dynamics and activities are indicators of risk to BV. To do this, we propose to conduct a high resolution prospective study in which samples collected daily from 200 reproductive-age women over two menstrual cycles are used to capture molecular events that take place before, during, and after the spontaneous remission of BV episodes. We will use modern genomic technologies to obtain the data needed to correlate shifts in vaginal microbial community composition and function, metabolomes, and epidemiological and behavioral metadata with the occurrence of BV to better define the syndrome itself and identify patterns that are predictive of BV. The three specific aims of the research are: (1) Evaluate the association between the dynamics of vaginal microbial communities and risk to BV by characterizing the community composition of vaginal specimens archived from a vaginal douching cessation study in which 33 women self-collected vaginal swabs twice-weekly for 16 weeks; (2) Enroll 135 women in a prospective study in which self-collected vaginal swab samples and secretions are collected daily along with data on the occurrence of BV, vaginal pH, and information on time varying habits and practices; (3) Apply model-based statistical clustering and classification approaches to associate the microbial community composition and function, with metadata and clinical diagnoses of BV. The large body of information generated will facilitate understanding vaginal microbial community dynamics, the etiology of BV, and drive the development of better diagnostic tools for BV. Furthermore, the information will enable a more personalized and effective treatment of BV and ultimately help prevent adverse sequelae associated with this highly prevalent disruption of the vaginal microbiome

Supersonic particles probes : : measurement ofinternal wall losses

Issued as Progress reports [nos. 1-7], and Final report, Project E-19-678 (subproject E-16-633

Supersonic particles probes : measurement ofinternal wall losses

Issued as final repor

Application of Ecological Network Theory to the Human Microbiome

In healthy humans, many microbial consortia constitute rich ecosystems with dozens to hundreds of species, finely tuned to functions relevant to human health. Medical interventions, lifestyle changes, and the normal rhythms of life sometimes upset the balance in microbial ecosystems, facilitating pathogen invasions or causing other clinically relevant problems. Some diseases, such as bacterial vaginosis, have exactly this sort of community etiology. Mathematical network theory is ideal for studying the ecological networks of interacting species that comprise the human microbiome. Theoretical networks require little consortia specific data to provide insight into both normal and disturbed microbial community functions, but it is easy to incorporate additional empirical data as it becomes available. We argue that understanding some diseases, such as bacterial vaginosis, requires a shift of focus from individual bacteria to (mathematical) networks of interacting populations, and that known emergent properties of these networks will provide insights that would be otherwise elusive

Reactivity of Haemophilus influenzae type b anti-pili antibodies

The reactivity of anti-pilus antibodies to native and denatured Haemophilus influenzae b (Hib) pili was studied using rabbit serum prepared against piliated H. influenzae b strain M43 (p+) and adsorbed with its non-piliated variant, strain M42 (p-). The specificity of the adsorbed serum for Hib pili was documented by immunogold electron microscopy and by immunoprecipitation, which revealed the 24 kDa pilin band from strain M43 (p+) that was not seen on strain M42 (p-1). In immunodot assays, the anti-pilus antibodies reacted with the native pili present on the outer membrane of strain M43 (p+), but on Western blot assay using denatured outer membranes, the anti-pilus antibodies did not react with the 24 kDa pilin subunit. These data demonstrate that the anti-pilus antibodies in the adsorbed serum recognize conformational epitopes that depend on the tertiary or quaternary structure of Hib pili.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27738/1/0000130.pd

Evidence for Acquisition in Nature of a Chromosomal 2,4-Dichlorophenoxyacetic Acid/(alpha)-Ketoglutarate Dioxygenase Gene by Different \u3ci\u3eBurkholderia\u3c/i\u3e spp.

We characterized the gene required to initiate the degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) by the soil bacterium Burkholderia sp. strain TFD6, which hybridized to the tfdA gene of the canonical 2,4-D catabolic plasmid pJP4 under low-stringency conditions. Cleavage of the ether bond of 2,4-D by cell extracts of TFD6 proceeded by an (alpha)-ketoglutarate-dependent reaction,characteristic of TfdA (F. Fukumori and R. P. Hausinger, J. Bacteriol. 175:2083-2086, 1993). The TFD6 tfdA gene was identified in a recombinant plasmid which complemented a tfdA transposon mutant of TFD6 created by chromosomal insertion of Tn5. The plasmid also expressed TfdA activity in Escherichia coli DH5(alpha), as evidenced by enzyme assays with cell extracts. Sequence analysis of the tfdA gene and flanking regions from strain TFD6 showed 99.5% similarity to a tfdA gene cloned from the chromosome of a different Burkholderia species (strain RASC) isolated from a widely separated geographical area. This chromosomal gene has 77.2% sequence identity to tfdA from plasmid pJP4 (Y. Suwa, W. E. Holben, and L. J. Forney, abstr. Q-403, in Abstracts of the 94th General Meeting of the American Society for Microbiology 1994.). The tfdA homologs cloned from strains TFD6 and RASC are the first chromosomally encoded 2,4-D catabolic genes to be reported. The occurrence of highly similar tfdA genes in different bacterial species suggests that this chromosomal gene can be horizontally transferred

Recent Advances in Understanding the Microbiology of the Female Reproductive Tract and the Causes of Premature Birth

Data derived from molecular microbiological investigations of the human vagina have led to the discovery of resident bacterial communities that exhibit marked differences in terms of species composition. All undergo dynamic changes that are likely due to intrinsic host and behavioral factors. Similar types of bacteria have been found in both amniotic fluid and the vagina, suggesting a potential route of colonization. Given that not all of the species involved in intrauterine infections are readily cultivated, it is important that culture-independent methods of analysis must be used to understand the etiology of these infections. Further research is needed to establish whether an ascending pathway from the vagina to the amniotic cavity enables the development of intrauterine infections