| 1. |
- Cheng, Liqin, et al.
(författare)
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A MicroRNA Gene Panel Predicts the Vaginal Microbiota Composition
- 2021
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Ingår i: mSystems. - : American Society for Microbiology. - 2379-5077. ; 6:3
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Tidskriftsartikel (refereegranskat)abstract
- The vaginal microbiota plays an essential role in vaginal health. The vaginas of many reproductive-age women are dominated by one of the Lactobacillus species. However, the vaginas of a large number of women are characterized by the colonization of several other anaerobes. Notably, some women with the non-Lactobacillus-dominated vaginal microbiota develop bacterial vaginosis, which has been correlated with sexually transmitted infections and other adverse outcomes. However, interactions and mechanisms linking the vaginal microbiota to host response are still under investigation. There are studies suggesting a link between human microRNAs and gut microbiota, but limited analysis has been carried out on the interplay of microRNAs and vaginal microbiota. In this study, we performed a microRNA expression array profiling on 67 vaginal samples from young Swedish women. MicroRNAs were clustered into distinct groups according to vaginal microbiota composition. Interestingly, 182 microRNAs were significantly elevated in their expression in the non-Lactobacillus-dominated community, suggesting an antagonistic relationship between Lactobacillus and microRNAs. Of the elevated microRNAs, 10 microRNAs displayed excellent diagnostic potential, visualized by receiver operating characteristics analysis. We further validated our findings in 34 independent samples where expression of top microRNA candidates strongly separated the Lactobacillus-dominated community from the non-Lactobacillus-dominated community in the vaginal microbiota. Notably, the Lactobacillus crispatus-dominated community showed the most profound differential microRNA expression compared with the non-Lactobacillus-dominated community. In conclusion, we demonstrate a strong relationship between the vaginal microbiota and numerous genital microRNAs, which may facilitate a deeper mechanistic interplay in this biological niche. IMPORTANCE Vaginal microbiota is correlated with women's health, where a non-Lactobacillus-dominated community predisposes women to a higher risk of disease, including human papillomavirus (HPV). However, the molecular relationship between the vaginal microbiota and host is largely unexplored. In this study, we investigated a link between the vaginal microbiota and host microRNAs in a group of young women. We uncovered an inverse correlation of the expression of microRNAs with the abundance of Lactobacillus species in the vaginal microbiota. Particularly, the expression of microRNA miR-23a-3p and miR-130a-3p, displaying significantly elevated levels in non-Lactobacillus-dominated communities, predicted the bacterial composition of the vaginal microbiota in an independent validation group. Since targeting of microRNAs is explored in the clinical setting, our results warrant investigation of whether microRNA modulation could be used for treating vaginosis recurrence and vaginosis-related diseases. Conversely, commensal bacteria could be used for treating diseases with microRNA aberrations.
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| 2. |
- Cheng, Liqin
(författare)
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Exploring the interaction between the human microbiota and infections
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The microbiota is a living ecosystem that is influenced by a variety of host and environmental factors. Distinct microbiota colonizes various body sites, such as the gastrointestinal system and vaginal tract, corresponding to the unique microenvironment. A healthy gut microbiota contains a stable, balanced, and highly diverse reservoir of microbes. Commensal microorganisms co-evolved with the host have conferred pathogen colonization resistance. Lactobacillus species usually dominate the vaginal microbiota of majority healthy women. The vaginal microbiota has also been linked to sexually transmitted diseases, such as the human papillomavirus (HPV) infection. MicroRNA expression was found to be associated with microbiota composition. We studied the interactions of microbiota gut and vagina with metabolites, miRNA expression, and HPV infection in our investigations. In vitro three- dimensional (3D) cell-culture methods were also analyzed and developed for mechanistic investigations of the microbiota-host interaction. Study I is a cross-sectional study investigating the microbiota features in HPV-related diseases. We defined the HPV-related microbial composition in a high-vaccination coverage population of 345 young Swedish women. The associations of microbial composition and the infection of 27 HPV types were analyzed. HPV infection, especially for the infection of oncogenic HPV types, was characterized by a higher microbial alpha-diversity with non- Lactobacillus-dominant vaginal microbiota composition. The prevalence of bacterial vaginosis-associated bacteria (BV AB), Sneathia, Prevotella, and Megasphaera were significantly higher in women with HPV infection than in uninfected individuals. Study II investigated the associations among miRNA, HPV infection, and vaginal microbiota composition. A global miRNA expression increase was identified in non-Lactobacillus- dominate women compared with Lactobacillus-dominated women. The top two differently expressed miRNA, miR-23a-3p and miR-130a-3p, showed a prediction accuracy of > 97% for distinguishing Lactobacillus-dominated and non- Lactobacillus-dominated samples. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of the target genes of miR-23a-3p and miR-130a-3p found that many pathways involved in cancer and infection were enriched, such as the mitogen-activated protein kinase (MAPK) signaling pathway, and the phosphatidylinositol 3-kinase (PI3K)-Akt signaling pathway. Study III explored the interactions between commensal bacteria and pathogens. We cocultured Salmonella with commensal bacteria isolations from an anaerobically cultivated human intestinal microflora (ACHIM). Commensal bacteria isolations belonging to the Clostridium and Eubacterium family showed significant inhibition of Salmonella growth. Following metabolite extraction and liquid chromatography-mass spectrometry analysis of the commensal bacteria and Salmonella metabolites in the coculture system of the commensal bacteria and Salmonella, adenine and adenosine were significantly higher in the coculture systems that inhibited Salmonella growth compared with the expressive systems. Functional assays of metabolite activity further validated the inhibition effect of adenine and adenosine on the growth of Salmonella and other antibiotic-resistant pathogens. Study IV established an anaerobic gut 3D model to study bacteria-host interactions. The Caco2 cells showed good cell viability and formed intestinal villi-like structures in our model. Anaerobic culture for 12 hours did not show a significant effect on the viability of cells, with only six genes differently expressed between cells cultured under anaerobic and aerobic conditions in RNA sequencing. RNA sequencing of Salmonella infected Caco2 cells cocultured in anaerobic conditions showed a large set of genes differentially expressed compared to aerobic conditions with the pathways associated with cell cycle, homologous recombination, and DNA replication. This supports our gut 3D model could be used for investigating host-microbe direct interactions under the anaerobic condition, which is essential for obligate anaerobic gut microbes.
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| 3. |
- Cheng, Liqin, et al.
(författare)
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The protective role of commensal gut microbes and their metabolites against bacterial pathogens
- 2024
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Ingår i: Gut microbes. - : Taylor & Francis. - 1949-0976 .- 1949-0984. ; 16:1
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Tidskriftsartikel (refereegranskat)abstract
- Multidrug-resistant microorganisms have become a major public health concern around the world. The gut microbiome is a gold mine for bioactive compounds that protect the human body from pathogens. We used a multi-omics approach that integrated whole-genome sequencing (WGS) of 74 commensal gut microbiome isolates with metabolome analysis to discover their metabolic interaction with Salmonella and other antibiotic-resistant pathogens. We evaluated differences in the functional potential of these selected isolates based on WGS annotation profiles. Furthermore, the top altered metabolites in co-culture supernatants of selected commensal gut microbiome isolates were identified including a series of dipeptides and examined for their ability to prevent the growth of various antibiotic-resistant bacteria. Our results provide compelling evidence that the gut microbiome produces metabolites, including the compound class of dipeptides that can potentially be applied for anti-infection medication, especially against antibiotic-resistant pathogens. Our established pipeline for the discovery and validation of bioactive metabolites from the gut microbiome as novel candidates for multidrug-resistant infections represents a new avenue for the discovery of antimicrobial lead structures.
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| 4. |
- Cheng, Liqin, et al.
(författare)
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Vaginal microbiota and human papillomavirus infection among young Swedish women
- 2020
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Ingår i: npj Biofilms and Microbiomes. - : Springer Science and Business Media LLC. - 2055-5008. ; 6:1
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Tidskriftsartikel (refereegranskat)abstract
- Human papillomavirus (HPV) infection is one of the most common sexually transmitted diseases. To define the HPV-associated microbial community among a high vaccination coverage population, we carried out a cross-sectional study with 345 young Swedish women. The microbial composition and its association with HPV infection, including 27 HPV types, were analyzed. Microbial alpha-diversity was found significantly higher in the HPV-infected group (especially with oncogenic HPV types and multiple HPV types), compared with the HPV negative group. The vaginal microbiota among HPV-infected women was characterized by a larger number of bacterial vaginosis-associated bacteria (BVAB), Sneathia, Prevotella, and Megasphaera. In addition, the correlation analysis demonstrated that twice as many women with non-Lactobacillus-dominant vaginal microbiota were infected with oncogenic HPV types, compared with L. crispatus-dominated vaginal microbiota. The data suggest that HPV infection, especially oncogenic HPV types, is strongly associated with a non-Lactobacillus-dominant vaginal microbiota, regardless of age and vaccination status.
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| 5. |
- Qiu, Liqin, et al.
(författare)
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Electrochemical deposition of Bi2Te3-based thin films
- 2010
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Ingår i: Journal of Physics and Chemistry of Solids. - : Elsevier BV. - 0022-3697 .- 1879-2553. ; 71:8, s. 1131-1136
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Tidskriftsartikel (refereegranskat)abstract
- The electrochemical reduction processes on stainless-steel substrates from an aqueous electrolyte composed of nitric acid, Bi3+, HTeO2+, SbO+ and H2SeO3 systems were investigated using cyclic voltammetry. The thin films with a stoichiometry of Bi2Te3, Bi0.5Sb1.5Te3 and Bi2Te2.7Se0.3 have been prepared by electrochemical deposition at selected potentials. The structure, composition, and morphology of the films were studied by X-ray diffraction (XRD), environmental scanning electron microscopy (ESEM) and electron microprobe analysis (EMPA). The results showed that the films were single phase with the rhombohedral Bi2Te3 structure. The morphology and growth orientation of the films were dependent on the deposition potentials.
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| 6. |
- Qu, Yifei, et al.
(författare)
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Isolation, Behavioral Identification, and Pathogenicity Assessment of Entomopathogenic Fungi from a Forest Wood Borer
- 2023
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Ingår i: Journal of Visualized Experiments. - 1940-087X. ; 2023:199
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Tidskriftsartikel (refereegranskat)abstract
- Forest wood borers (FWB) cause severe tree damage and economic losses worldwide. The release of entomopathogenic fungi (EPF) during the FWB emergence period is considered an acceptable alternative to chemical control. However, EPF resources have been significantly less explored for FWBs, in contrast to agricultural insect pests. This paper presents a protocol for exploring EPF resources from FWBs using wild Monochamus alternatus populations as an example. In this protocol, the assignment of traps baited with M. alternatus attractants to different populations guaranteed the collection of adequate samples with natural infection symptoms, during the emergence periods of the beetle. Following finely dissecting integuments and placing them onto a selective medium, fungal species were isolated from each part of beetle bodies and identified based on both molecular and morphological traits. Several fungal species were certified as parasitic EPFs via re-infection of healthy M. alternatus with spore suspensions. Their behavioral phenotypes on M. alternatus were observed using scanning electron microscopy and further compared with those on the Coleopteran model insect Tribolium castaneum. For EPFs that present consistent parasitism phenotypes on both beetle species, evaluation of their activities on T. castaneum provided valuable information on lethality for future study on M. alternatus. This protocol helped the discovery of EPF newly reported on M. alternatus populations in China, which could be applied as an efficient approach to explore more EPF resources from other FWBs.
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| 7. |
- Sterpu, Irene, et al.
(författare)
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No evidence for a placental microbiome in human pregnancies at term
- 2021
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Ingår i: American Journal of Obstetrics and Gynecology. - : Elsevier. - 0002-9378 .- 1097-6868. ; 224:3, s. 296.e1-296.e23
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Tidskriftsartikel (refereegranskat)abstract
- Background: The placenta plays an important role in the modulation of pregnancy immunity; however, there is no consensus regarding the existence of a placental microbiome in healthy full-term pregnancies.Objective: This study aimed to investigate the existence and origin of a placental microbiome.Study Design: A cross-sectional study comparing samples (3 layers of placental tissue, amniotic fluid, vernix caseosa, and saliva, vaginal, and rectal samples) from 2 groups of full-term births: 50 women not in labor with elective cesarean deliveries and 26 with vaginal deliveries. The comparisons were performed using polymerase chain reaction amplification and DNA sequencing techniques and bacterial culture experiments.Result: There were no significant differences regarding background characteristics between women who delivered by elective cesarean and those who delivered vaginally. Quantitative measurements of bacterial content in all 3 placental layers (quantitative polymerase chain reaction of the 16S ribosomal RNA gene) did not show any significant difference among any of the sample types and the negative controls. Here, 16S ribosomal RNA gene sequencing of the maternal side of the placenta could not differentiate between bacteria in the placental tissue and contamination of the laboratory reagents with bacterial DNA. Probe-specific quantitative polymerase chain reaction for bacterial taxa suspected to be present in the placenta could not detect any statistically significant difference between the 2 groups. In bacterial cultures, substantially more bacteria were observed in the placenta layers from vaginal deliveries than those from cesarean deliveries. In addition, 16S ribosomal RNA gene sequencing of bacterial colonies revealed that most of the bacteria that grew on the plates were genera typically found in human skin; moreover, it revealed that placentas delivered vaginally contained a high prevalence of common vaginal bacteria. Bacterial growth inhibition experiments indicated that placental tissue may facilitate the inhibition of bacterial growth.Conclusion: We found no evidence to support the existence of a placental microbiome in our study of 76 term pregnancies, which used polymerase chain reaction amplification and sequencing techniques and bacterial culture experiments. Incidental findings of bacterial species could be due to contamination or to low-grade bacterial presence in some locations; such bacteria do not represent a placental microbiome per se.
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| 8. |
- Wu, Shengru, et al.
(författare)
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Tonsillar microbiota : A cross-sectional study of patients with chronic tonsillitis or tonsillar hypertrophy
- 2021
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Ingår i: mSystems. - 2379-5077. ; 6:2
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Tidskriftsartikel (refereegranskat)abstract
- Chronic tonsillitis (CT) and tonsillar hypertrophy (TH) are common tonsillar diseases that are related to infection and inflammation. Little is known about tonsillar microbiota and its role in CT and TH. This study aims to identify palatine tonsillar microbiota both on the surface and in the core tissues of CT and TH patients. In total, 22 palatine tonsils were removed and collected from CT and TH patients who underwent surgery. The surface and core microbiota in the tonsils of CT and TH patients were compared using 16S rRNA gene sequencing of V3-V4 regions. Differential tonsillar microbiotas were found in the CT versus TH patients and surface versus core tissues. Further, a higher relative abundance of bacterial genera, including Haemophilus, Streptococcus, Neisseria, Capnocytophaga, Kingella, Moraxella, and Lachnospiraceae [G-2] in patients with TH and Dialister, Parvimonas, Bacteroidales [G-2], Aggregatibacter, and Atopobium in patients with CT, was observed. Of these, the differential genera of Dialister, Parvimonas, and Neisseria served as key factors in the tonsillar microbiota network. Notably, four representable tonsillar microbial types were identified, with one, consisting of a higher abundance of Haemophilus and Neisseria, exclusively detected in the TH patients. This study analyzed the different tonsillar microbiota from the surface and core tissues of CT and TH patients. Several bacteria and various microbial types related to CT and TH were identified, along with potential bacterial networks and related immune pathways.IMPORTANCE: The human microbiota has been shown to be functionally connected to infectious and inflammation-related diseases. So far, only limited studies had been performed on tonsillar microbiota, although tonsils play an essential role in the human immune defense system and encountered numerous microorganisms. Our work presented different tonsillar microbiota from surface and core tissues of chronic tonsillitis (CT) and tonsillar hypertrophy (TH) patients. Notably, one tonsillar microbiota type, which contains a higher abundance of Haemophilus and Neisseria, was only detected in the TH patients. Furthermore, certain bacteria, such as Haemophilus, Neisseria, Dialister, and Parvimonas, may serve as microbial biomarkers to discriminate CT patients from TH patients. These data provide important microbiota data in the tonsillar research area and are highly useful for researchers both in the oral microbiome field and clinical field.
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