Medicine in Microecology最新文献

Influenza is an age-old disease. With its pandemic spread over various centuries, the virus remains one of the most challenging ones in the environment. Its fast-changing genome, RNA, is highly dynamic, and new variants of all the strains are discovered each year. Influenza A remains the most prevalent strain to infect the human race. With its fast multiplication rate, a sudden spike in hospitalization and high demand for antiviral drugs is seen during flu seasons. Antiviral drugs are considered the most suitable and specific since they attack particular steps of viral replication and halt it. Amantadine and Rimantadine were quite successful in their time, but the discovery of resistant strains of the virus limited humans from using it as a potent drug. Against all odds, the duo still provides a lot of information to learn from and implement in the field of research and also forms a base for discovering or formulating a more potent and long-lasting drug. Even though people rely more on vaccines, it is because of these drugs that any unprecedented situations, even in the vaccinated individuals, can be prevented and the lives of numerous patients can be saved. Amongst all the drugs, Baloxavir marboxil, Zanamivir, and Peramivir are preferred by most health systems because of their recent discovery, highly specific nature, and even high bioavailability. Parallel to antiviral drugs, nanotechnology is emerging as a new alternative for the treatment of Influenza.

The biofilm is a bacterial colony wrapped in an auto-produced polymer matrix of polysaccharides, proteins, and DNA. Bacterial biofilms cause persistent infections because they are more resistant to antibiotics, disinfectants, and the immune system of the body. Other significant biofilm characteristics are a gradient of oxygen and nutrition from the top layer to the bottom layer of biofilms. Lower bacterial cell metabolic activity and longer doubling rates are linked to the gradients; these are the quiescent cells responsible for some of the resistance to antibiotics. Biofilms may be avoided and cured with vigorous antibiotic prophylaxis or treatment early on and with continuous suppressive medication. This review discusses the development of antibiotic resistance and tolerance in bacteria due to biofilm formation, the tolerance mechanisms, and the development of persistent cells that induce antibiotic resistance in bacteria. Recent strategies to combat antibiotic resistance are also discussed.

Background

Microbiomes have been identified in various tumor types and could affect tumor progression and treatment. As the most prevalent primary malignant eye tumor in adults, uveal melanoma (UM) has not been explored regarding its endogenous microbiome. Plaque radiotherapy (PRT) is the gold standard for the treatment of UM. Hereby, we recruited 71 UM patients, sequenced the 16S rRNA gene of their tumor tissues, and analyzed the association between UM microbiome and disease phenotypes.

Results

Clear bacterial signals were observed in UM tissues using fluorescence in situ hybridization. 450 bacterial species passed strict decontamination against 58 environmental control samples in 16S rRNA gene analysis, and these species formed three distinct types by unsupervised clustering. The UM microbiome types were significantly associated with PRT. A biomarker analysis showed that Pseudomonas was significantly enriched in the radiation group (RG) compared to the non-radiation group (NRG). A kind of radiation-resistant bacteria had a significantly higher positive rate in tumor tissues that underwent radiotherapy. We found that the radio-resistant bacteria Deinococcus was associated with smaller and earlier tumor stages, while Pseudomonas and Stenotrophomonas were associated with later metastasis.

Conclusion

An endogenous microbiome might exist in UM tissues and was associated with UM features and treatment. Whether the tumor-residing microbiome has a role in UM development and metastasis is worth further investigation.

Bacterial vaginosis (BV) is a polymicrobial vaginal dysbiosis alongside lactobacillus depletion that primarily affects women of reproductive age. The fishy odor vaginal discharge is the major cause of anaerobic pathogenic bacteria colonization. Symptomatic women face specific catastrophic physiological and immunopathological consequences in addition to an elevated risk of sexually transmitted infections. Further, rash antibiotic therapy has witnessed antimicrobial-resistance amplifying vaginal infections. The emergence of biofilm-associated antimicrobial-resistance has made the issue worsened. This article has gone on to explore novel regimens, advanced diagnosis, and various cutting-edge strategies that are found to be effective in addressing these problems and restoring vaginal health.

The aryl hydrocarbon receptor (AhR) is a ligand-dependent transcription factor that serves as a key environmental sensor and mechanistic regulator of both the epithelial barrier and systemic immunity. Exogenous ligands (aromatic compounds such as dioxins) and endogenous ligands (tryptophan and its metabolite family) are the two types of AhR ligands. In particular, certain gut flora contain enzymes involved in the metabolism of tryptophan to AhR ligands, and Lactobacillus is attractive among all intestinal flora which are capable of producing AhR ligands. This research reviews the probiotic effects of Lactobacillus reuteri and other Lactobacilli on immunological responses and gut barrier function via the AhR pathway, and it also provides evidence to support the probiotics as an alternative therapy for some specific diseases in the future.

Branched chain amino acids (BCAAs) are essential amino acids required by mammals. Recently, accumulating evidence has revealed the important connection between the alterations of BCAAs and their metabolites in circulation and the development and prognosis of chronic metabolic diseases, especially obesity and type 2 diabetes mellitus (T2DM). The connection strongly suggests the pivotal role of dysregulated BCAA metabolism in obesity and T2DM. More importantly, BCAA anabolic and catabolic defects in host and gut microbiome often intertwine with glucose and lipid metabolism, which synergistically promote systemic insulin resistance and obesity/T2DM progression. However, the mutual effects of BCAA with glucose/lipid metabolism in different tissues of the host and the association of BCAA with gut microbiota, are not fully understood and summarized. In the current review, we focus on the mutual effects of BCAA with glucose/lipid metabolism in the host and gut microbiota modulation of BCAA metabolism, and further discuss the metabolic regulatory effects on the development of obesity and T2DM.

Imbalance in the microbiota has been identified in Crohn's disease (CD). We explored the difference of the microbiota in fecal and intestinal mucosa (including ileocecal junction, terminal ileum and transverse colon) in pediatric patients with active CD, CD patients in remission, nonspecific enteritis (NE) and the healthy children. Seven children had active CD, 5 cases of patients achieve remission (CDR), 19 were NE patients, and 11 were healthy controls (Col). A total of 168 samples were collected. Microbiota compositions were analyzed using 16 ​S rRNA sequencing. The results showed that, in fecal samples, Clostridium_sensu_stricto, Enterobacter and Akkermansia had a higher relative abundance in the CD group than that in CDR, Col and NE groups. Fusobacterium and Streptococcus showed a higher abundance in both CD and CDR than that in Col group. In intestinal mucosa samples, the bacterial communities of the three sampling sites were extremely similar. Escherichia-Shigella was the most abundant mucosal bacteria in the CD group, and the abundance of Bacillus, Ruminococcus_torques_group, Streptococcus, Faecalibacterium and Blautia was lower in the CD group than in other groups. In conclusion, as a very characteristic bacteria, the abundance of Escherichia-Shigella in the intestinal mucosa can be used as a diagnostic criterion for CD patients. Also, the Bacilus and Blautia, which were not as prominent as Escherichia-Shigella could still be used as a diagnostic candidate due to their neatness in CD patients. Mucosal samples may be better than stool samples when assessing the community and diversity of patients' intestinal microbes.

Cervical cancer is a global health concern. Persistent oncogenic human papillomavirus (HPV) infection is a prerequisite for the development of cervical cancer. Emerging research indicates that the vaginal microbiota may play both protective and harmful roles in the acquisition and persistence of HPV and the development of cervical cancer. This multicenter cohort study mainly aims to reveal the association of vaginal microbiota with the outcome of HPV infection in six months in women of reproductive age. We will recruit 50 research centers and enroll a total of about 10,000 female volunteers with a series of strict inclusion and exclusion criteria across China, including HPV positive and HPV negative women. A unified questionnaire will be used to obtain the sociodemographic information, clinical data and lifestyle of all volunteers. Specimens including vaginal secretions swabs and cervical exfoliated cells will be collected at the first visit and follow-up after six months. We will use 16S rRNA sequencing to characterize the vaginal microbiota of volunteers’ vaginal swabs. Twenty-one HPV genotypes and other sexually transmitted pathogens, including Neisseria gonorrhoeae, Chlamydia trachomatis, Ureaplasma urealyticum, Mycoplasma hominis, Mycoplasma genitalium and Herpes simplex virus type Ⅱ will be examined using flow-through hybridization and gene chip. The association of HPV infection and vaginal microbiota will be investigated, and the core microbiota attributes to the persistent HPV infection will be analyzed in this study.

Gastric cancer (GC) is one of the most common types of cancer and continues to threaten human health. The microbiota plays an important role in health and disease, including GC. Dysbiosis of gut microbiota has been reported to be associated with various diseases. There are no published meta-analyses of gut microbiota alterations in patients with GC in China. A meta-analysis was performed by searching the PubMed, Web of Science, EMBASE, and Cochrane Library databases up to July 2022. Nine eligible studies, representing 405 patients, were included in the analysis. At the phylum level, Proteobacteria (mean difference 12.46 (3.06–21.87), p ​< ​0.05) was significantly increased, and Firmicutes (mean difference −4.10 (−7.65 to −0.56), p ​< ​0.05) was decreased in patients with GC. At the genus level, Desulfovibrio (mean difference 0.38 (0.16–0.59); p ​< ​0.05) and Streptococcus (mean difference 1.92 (0.37–3.46), p ​< ​0.05) were significantly increased in patients with GC. No significant difference was observed in gut microbial diversity between patients and non-GC controls. Subgroup analysis suggested that region, sample size, and quality of studies caused heterogeneity to different extents. In summary, our study indicated a difference in gut microbial composition between patients with GC and individuals without GC. No significant differences were observed in the diversity of the gut microbes. Changes in the gut microbiota of patients with GC could potentially be used for the non-invasive diagnosis of GC.

Caries is a dental disease that can affect oral and psychological health and has a high incidence in children. The role of fungal flora in childhood caries has not been fully described. In this study, we aimed to investigate the fungal composition differences and the influencing factors in unstimulated saliva (S) and supragingival plaque (P) samples in childhood caries. S and P samples were collected from 63 children with caries. The ITS2 region in the fungal genome was then amplified and sequenced. Subsequently, we quantified and analyzed the fungal compositions in the samples. Cryptococcus was the most abundant genus in the S and P subgroups. The relative abundances of Cryptococcus and Wickerhamomyces significantly differed between the S and P subgroups (p ​< ​0.05). Significant differences were also observed in alpha and beta diversities between the two subgroups (p ​< ​0.05). However, no significant differences were observed between the mycobiome of the SFe and SMa subgroups or the PFe and PMa subgroups (p ​> ​0.05). Conversely, species differences were detected between the SDD and SMD subgroups (p ​< ​0.05) but not in the PDD and PPD subgroups (p ​> ​0.05). Our findings revealed significant differences in the mycobiome of unstimulated saliva and supragingival plaque. Dentition period and oral hygiene behaviors may have affected these differences.