Exploring the putative interactions between chronic kidney disease and chronic periodontitis.

Chronic kidney disease (CKD) and chronic periodontitis (CP) are both common diseases, which are found disproportionately comorbid with each other and have been reported to have a detrimental effect on the progression of each respective disease. They have an overlap in risk factors and both are a source of systemic inflammation along with a wide selection of immunological and non-specific effects that can affect the body over the lifespan of the conditions. Previous studies have investigated the directionality of the relationship between these two diseases; however, there is a lack of literature that has examined how these diseases may be interacting at the localized and systemic level. This review discusses how oral microorganisms have the ability to translocate and have distal effects and provides evidence for microbial involvement in a systemic disease. Furthermore, it summarizes the reported local and systemic effects of CKD and CP and discusses how the interaction of these effects may be responsible for directionality associations reported.

A Bacteroidetes locus dedicated to fungal 1,6-ß-glucan degradation: Unique substrate conformation drives specificity of the key endo-1,6-ß-glucanase.

Glycans are major nutrients available to the human gut microbiota. The Bacteroides are generalist glycan degraders, and this function is mediated largely by polysaccharide utilization loci (PULs). The genomes of several Bacteroides species contain a PUL, PUL1,6-ß-glucan, that was predicted to target mixed linked plant 1,3;1,4-ß-glucans. To test this hypothesis we characterized the proteins encoded by this locus in Bacteroides thetaiotaomicron, a member of the human gut microbiota. We show here that PUL1,6-ß-glucan does not orchestrate the degradation of a plant polysaccharide but targets a fungal cell wall glycan, 1,6-ß-glucan, which is a growth substrate for the bacterium. The locus is up-regulated by 1,6-ß-glucan and encodes two enzymes, a surface endo-1,6-ß-glucanase, BT3312, and a periplasmic ß-glucosidase that targets primarily 1,6-ß-glucans. The non-catalytic proteins encoded by PUL1,6-ß-glucan target 1,6-ß-glucans and comprise a surface glycan-binding protein and a SusD homologue that delivers glycans to the outer membrane transporter. We identified the central role of the endo-1,6-ß-glucanase in 1,6-ß-glucan depolymerization by deleting bt3312, which prevented the growth of B. thetaiotaomicron on 1,6-ß-glucan. The crystal structure of BT3312 in complex with ß-glucosyl-1,6-deoxynojirimycin revealed a TIM barrel catalytic domain that contains a deep substrate-binding cleft tailored to accommodate the hook-like structure adopted by 1,6-ß-glucan. Specificity is driven by the complementarity of the enzyme active site cleft and the conformation of the substrate. We also noted that PUL1,6-ß-glucan is syntenic to many PULs from other Bacteroidetes, suggesting that utilization of yeast and fungal cell wall 1,6-ß-glucans is a widespread adaptation within the human microbiota.

Analysis of Cellular Damage Resulting from Exposure of Bacteria to Graphene Oxide and Hybrids Using Fourier Transform Infrared Spectroscopy.

With the increase in antimicrobial resistance, there is an urgent need to find new antimicrobials. Four particulate antimicrobial compounds, graphite (G), graphene oxide (GO), silver-graphene oxide (Ag-GO) and zinc oxide-graphene oxide (ZnO-GO) were tested against Enterococcus faecium, Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus. The antimicrobial effects on the cellular ultrastructure were determined using Fourier transform infrared spectroscopy (FTIR), and selected FTIR spectral metrics correlated with cell damage and death arising from exposure to the GO hybrids. Ag-GO caused the most severe damage to the cellular ultrastructure, whilst GO caused intermediate damage. Graphite exposure caused unexpectedly high levels of damage to E. coli, whereas ZnO-GO exposure led to relatively low levels of damage. The Gram-negative bacteria demonstrated a stronger correlation between FTIR metrics, indicated by the perturbation index and the minimal bactericidal concentration (MBC). The blue shift of the combined ester carbonyl and amide I band was stronger for the Gram-negative varieties. FTIR metrics tended to provide a better assessment of cell damage based on correlation with cellular imaging and indicated that damage to the lipopolysaccharide, peptidoglycan and phospholipid bilayers had occurred. Further investigations into the cell damage caused by the GO-based materials will allow the development of this type of carbon-based multimode antimicrobials.

The impact of a virtual cardiology outpatient clinic in the COVID-19 era.

BACKGROUND: Restrictions as a result of the COVID-19 pandemic have demanded an innovative approach to provide appropriate patient review. We have been running virtual cardiology clinics as per Health Service Executive guidance. AIMS: Our study aims to determine how virtual clinics change practice vs traditional clinics. METHODS: A retrospective cohort analysis was conducted on patients attending cardiology clinics in our hospital from 6 January to 13 March 2020 ('traditional clinic', n = 1644), compared with clinics during the COVID-19 outbreak, from 16 March to 22 April 2020 ('virtual clinic', n = 691), with the same medical staff. RESULTS: There was no difference in age (61 vs 60), case mix or new vs return appointments in virtual vs traditional clinics. There were similar rates of clinic participation, 71.8% vs 74.2%. A lower proportion of investigations (e.g. imaging) were booked in virtual (38.5%) vs traditional (55.7%) clinics, p < 0.00001. Management changes (e.g. medication changes) were less frequent in virtual (19.9%) vs traditional (38.5%) clinics, p < 0.00001. However, the discharge rate was higher in virtual (28.8%) vs traditional (19.5%) clinics, p = 0.00003. CONCLUSION: This study highlights that virtual clinic consultations are associated with fewer investigations, fewer management changes, and increased discharge rates compared with traditional consultations. These practice changes would reduce costs and hospital outpatient congestion by avoiding unnecessary hospital reviews. Nonetheless, it is unknown whether patients requiring face-to-face consultations could be missed as a result of this virtual approach. Longitudinal studies are required to assess clinical outcomes as a result of these practice changes and whether patient satisfaction is altered.

A novel microbiological medium for the growth of periodontitis associated pathogens.

A novel microbiological medium designed to be more representative of gingival crevicular fluid. Chosen representative periodontal microorganisms showed good growth with minimal effect on human cell viability. This will enable more comparisons between different periodontitis associated organisms and their potential role in host health and systemic disease.