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Tyc, K.

Publications and source records attributed to Tyc, K..

2 recordsLinked to original sources

HPV co-infection burden, vaginal microbiota restructuring, and host context are associated with Cervical precancer risk in a racially restricted observational cohort

BackgroundHigh-risk human papillomavirus (HPV) infection is necessary for cervical carcinogenesis, but HPV detection alone does not distinguish transient infection from lesions at greatest risk of progression. We evaluated whether HPV burden, vaginal microbiota structure, and host-context variables jointly characterize cervical intraepithelial neoplasia grade 3 (CIN3) in a Black/African American and White analytic cohort from the Vaginal Microbiome Health Project (VaMHP), integrating L1-based HPV typing, 16S rRNA vaginal microbiota profiling, and linked clinical metadata. ResultsAmong 1181 participants, 75 had CIN3. CIN3 was associated with HPV positivity (55/75, 73.3% vs 431/1106, 39.0%; odds ratio [OR] 4.31, 95% CI 2.55-7.29; Fisher exact p = 7.9 x 10^-9) and with multiple HPV infection among HPV-positive participants (35/55, 63.6% vs 176/431, 40.8%; OR 2.54, 95% CI 1.42-4.54; p = 0.0022). HPV communities in CIN3-positive samples showed higher Shannon diversity, greater observed strain richness, higher evenness, and significant beta-diversity separation. In vaginal microbiota analyses, alpha diversity did not differ by CIN3 status, but community composition did, and Lactobacillus crispatus was the only taxon depleted in CIN3 after multiple-testing correction. Race, age, and metronidazole exposure were central nodes in the host-factor network. In predictive modeling, a full integrated model combining metadata, HPV, and vaginal microbiota features (auROC = 0.745) outperformed both HPV + vaginal microbiota (auROC = 0.670) and HPV-only (auROC = 0.440) models. ConclusionsCIN3 in this cohort was associated with coordinated shifts in virologic burden, vaginal community structure, and host social-clinical context. The results support a structure-function interpretation in which loss of Lactobacillus crispatus-dominant states and enrichment of dysbiosis-associated communities define a host-microbiome context that is more permissive to HPV persistence and precancer. These findings move beyond descriptive omics by showing that microbiome and host-context features add nonredundant discriminatory signal beyond HPV-only models.

microbiology↗

A genome-wide in vivo screen reveals fitness pathways required for streptococcal infective endocarditis

Infective endocarditis (IE) is a life-threatening disease most often caused by blood-borne bacteria that infect previously damaged cardiac tissue. Despite the importance of this disease, the genetic basis for IE virulence remains poorly defined. Here, we present the first genome-wide in vivo analysis of bacterial fitness in a vertebrate model of IE. We identified 146 genes in Streptococcus sanguinis required for IE fitness, the majority of which had not previously been linked to endocarditis. These determinants cluster into conserved metabolic, cell envelope, transport, and regulatory pathways, representing a vast reservoir of potential targets for novel antimicrobial intervention. A subset of these genes was examined in Streptococcus mutans; all were found to be essential for IE fitness in this distantly related oral species as well, suggesting broad conservation. Using experimental evolution, we further show that disruption of key fitness pathways triggers reproducible compensatory "bypass" mechanisms that reveal the inherent physiological constraints of the IE fitness landscape and identify vulnerable nodes for multi-target drug strategies. Together, these findings redefine streptococcal infective endocarditis as a disease shaped by conserved bacterial fitness networks that may be exploited for therapeutic development. HighlightsO_LIA genome-wide in vivo screen identified 146 Streptococcus sanguinis genes required for infective endocarditis fitness. C_LIO_LI94% of these genes represent previously unrecognized determinants of endocarditis. C_LIO_LIMultiple pathways--including CoA biosynthesis, the shikimate pathway, and rhamnan synthesis--are required for cardiac colonization. C_LIO_LIA subset of infective endocarditis fitness factors are conserved between S. sanguinis and S. mutans, with species-specific adaptations. C_LIO_LIExperimental evolution revealed compensatory metabolic networks that buffer IE fitness defects. C_LI

genetics↗