Biology subjects

Hasturk, H.

Publications and source records attributed to Hasturk, H..

3 recordsLinked to original sources

bioRxiv2024

Sustaining healthy long-term host-microbiome interactions in a physiologically relevant dynamic gingival tissue model

Host-oral microbiome interactions are known to be critical in maintaining local and systemic health of the human body, although they are difficult to study in both clinical and in vitro applications. Despite efforts, recapitulation of gingival architecture and physiological characteristics of the periodontal niche cannot be achieved by traditional tissue engineering strategies. Here, we advanced our humanized three-dimensional gingival model by co-culturing it with a healthy patient-derived microbiomes for seven days within an oral bioreactor that mimics native salivary dynamics. Our results indicated long-term host and microbiome viability, host barrier integrity and physiological response, and preservation of healthy microbial populations and interbacterial dialogues. The model has proven useful in successfully mimicking tissue homeostasis at the interface of the periodontal niche and suitable for the introduction of immune cells. Future studies will focus on using the model as a comparator of periodontal inflammation and identifying biomarkers associated with eubiotic/dysbiotic profiles. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=137 SRC="FIGDIR/small/577629v1_ufig1.gif" ALT="Figure 1"> View larger version (50K): org.highwire.dtl.DTLVardef@1bc808aorg.highwire.dtl.DTLVardef@9b0ef8org.highwire.dtl.DTLVardef@1f3fbb1org.highwire.dtl.DTLVardef@11135f5_HPS_FORMAT_FIGEXP M_FIG Created partially in biorender.com. C_FIG

bioengineering↗

bioRxiv2023

Persistent enrichment of multidrug resistant Klebsiella in oral and nasal communities during long-term starvation

The human oral and nasal cavities can act as reservoirs for opportunistic pathogens capable of causing acute infection. These microbes asymptomatically colonize the human oral and nasal cavities which facilitates transmission within human populations via the environment, and they routinely possess a clinically-significant antibiotic-resistance genes. Among these opportunistic pathogens, the Klebsiella genus stands out as a notable example, with its members frequently linked to nosocomial infections and multidrug resistance. As with many colonizing opportunistic pathogens, how Klebsiella transitions from an asymptomatic colonizer to a pathogen remains unclear. Here, we explored a possible explanation by investigating the ability of oral and nasal Klebsiella to outcompete their native microbial community members under in vitro starvation conditions, which could be analogous to external hospital environments. When Klebsiella was present within a healthy human oral or nasal sample, the bacterial community composition shifted dramatically under starvation conditions and typically became dominated by Klebsiella. Furthermore, introducing K. pneumoniae exogenously into a native microbial community lacking K. pneumoniae, even at low inoculum, led to repeated dominance under starvation. K.pneumoniae strains isolated from healthy individuals oral and nasal cavities also exhibited resistance to multiple classes of antibiotics and were genetically similar to clinical and gut isolates. In addition, we found that in the absence of Klebsiella, other understudied opportunistic pathogens, such as Peptostreptococcus, dominate under starvation conditions. Our findings establish an environmental circumstance that allows for the outgrowth of Klebsiella and other opportunistic pathogens. The ability to outcompete other commensal bacteria and to persist under harsh environmental conditions may contribute to the colonization-to-infection transition of these opportunistic pathogens.

microbiology↗

bioRxiv2022

Three-dimensional humanized gingival tissue model to study oral microbiome

The oral cavity contains different microenvironments, as the non-shedding surface of the teeth and the epithelial mucosa, where oral barriers and microbial communities coexist. The interactions and balances between these two communities are responsible for oral tissue homeostasis or dysbiosis, that ultimately dictate health or disease. Disruption of this equilibrium is the first necessary step towards chronic inflammation and permanent tissue damage in the case of chronic periodontitis. There are currently no experimental models able to mimic the structural, physical, and metabolic conditions present in the oral gingival tissue to support the long-term investigation of host-pathogens unbalances. Herein, we report a 3D anatomical gingival in vitro model based on human primary culture that recapitulates the native tissue organization, and a native oxygen gradient within the gingival pocket to support human microbiome persistence with a physiologically relevant level of microbial diversity as well as native spatial organization. The modulation of inflammatory markers in the presence of oral microbiome suggested the humanized functional response of this model. The model will be used in future studies to investigate host-pathogen unbalances in gingivitis and periodontal disease.

bioengineering↗