Effects of Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans on Modeling Subgingival Microbiome and Impairment of Oral Epithelial Barrier.

Periodontitis is an exemplar of dysbiosis associated with the coordinated action of multiple members within the microbial consortium. The polymicrobial synergy and dysbiosis hypothesis proposes a dynamic host-microbiome balance, with certain modulators capable of disrupting eubiosis and driving shifts towards dysbiosis within the community. However, these factors remain to be explored. We established a Porphyromonas gingivalis- or Aggregatibacter actinomycetemcomitans-modified subgingival microbiome model and 16S rRNA sequencing revealed that P. gingivalis and A. actinomycetemcomitans altered the microbiome structure and composition indicated by α and ß diversity metrics. P. gingivalis increased the subgingival dysbiosis index (SDI), while A. actinomycetemcomitans resulted in a lower SDI. Furthermore, P. gingivalis-stimulated microbiomes compromised epithelium function and reduced expression of tight junction proteins, whereas A. actinomycetemcomitans yielded mild effects. In conclusion, by inoculating P. gingivalis, we created dysbiotic microcosm biofilms in vitro resembling periodontitis-related subgingival microbiota, exhibiting enhanced dysbiosis and impaired epithelium integrity.

Amphotericin B and micafungin duo-loaded nanoemulsion as a potential strategy against Candida auris biofilms.

Candida auris is a multidrug-resistant yeast that has seen a worrying increase during the COVID-19 pandemic. Give7/n this, new therapeutic options, such as controlled-release nanomaterials, may be promising in combating the infection. Therefore, this study aimed to develop amphotericin B (AmB) and micafungin (MICA)-loaded nanoemulsions (NEMA) and evaluated against biofilms of C. auris. Nanoemulsions (NEs) were characterized and determined minimum inhibitory concentration MIC90, checkerboard and anti-biofilm. NEMA presented a size of 53.7 and 81.4 nm for DLS and NTA, respectively, with good stability and spherical morphology. MICAmB incorporated efficiency was 88.4 and 99.3%, respectively. The release results show that AmB and MICA obtained a release of 100 and 63.4%, respectively. MICAmB and NEMA showed MIC90 values of 0.015 and 0.031 ug/mL, respectively and synergism. NEMA showed greater metabolic inhibition and morphological changes in mature biofilms. This drugs combination and co-encapsulation proved to be a promising therapy against C. auris biofilms.

The Intriguing Pattern of Nontuberculous Mycobacteria in Bulgaria and Description of Mycobacterium bulgaricum sp. nov.

We investigated the rise of nontuberculous mycobacteria (NTM) infections in Bulgaria, focusing on species identification and distribution from 2018 to 2022. Utilizing advanced diagnostic tools, including the Hain Mycobacterium CM/AS method, Myco-biochip assay, and whole-genome sequencing, the study identifies and characterizes a diverse range of Mycobacterium species from clinical samples. While M. avium, M. gordonae, M. fortuitum, and M. chelonae were dominating, a number of rare species were also found. They include such species as M. marseillense and M. celatum. Moreover, the noticeable prevalence of M. terrae complex species missed by conventional testing was observed. We identified a rare species, highly homologous to previously described strains from Japan; based on genome-genome distance data, we propose its reannotation as a new species. Further, a novel species was identified, which is significantly distinct from its closest neighbor, M. iranicum, with ANI = 87.18%. Based on the SeqCode procedure, we propose to name this new species Mycobacterium bulgaricum sp. nov. Dynamic changes in NTM species prevalence in Bulgaria observed from 2011 to 2022 highlight the emergence of new species and variations tied to environmental and demographic factors. This underscores the importance of accurate species identification and genotyping for understanding NTM epidemiology, informing public health strategies, and enhancing diagnostic accuracy and treatment protocols.

Microbially produced fertilizer provides rhizobacteria to hydroponic tomato roots by forming beneficial biofilms.

Hydroponic cultivation of Solanum lycopersicum (tomato) is important, and high tomato production depends on the use of nitrogen and phosphate fertilizers. We had developed a microbial fertilizer (MF), which is mainly composed of nitrate. To investigate the effect of MF on plant growth, hydroponic tomato was grown with MF or commercial inorganic fertilizer (IF), and the microbiomes of the rhizosphere and the liquid phase were analyzed by confocal microscopy and high-throughput sequencing. Plant biomass and biofilm formation were increased by growth in MF compared to IF. The microbial community structures of tomato roots and hydroponic water differed between the two conditions, and three operational taxonomic units (OTUs) dominated in plants grown with MF. The three OTUs were related to Rudaea spp., Chitinophaga spp., and Stenotrophobacter terrae, which are reported to be disease-suppressive epiphytic or endophytic microbes of plant roots. Because these three OTUs also predominated in the MF itself, they were likely provided to the rhizosphere or endophytic environments of tomato roots via hydroponic water. KEY POINTS: • Microbial fertilizer for hydroponic growth enhanced biofilm formation on tomato root. • Microbial fertilizer contains tomato-root epiphytic or endophytic microbes. • Microbial fertilizer provided beneficial microbes to the rhizosphere and endophytic environments of tomato roots via hydroponic water.

COVID-19, stigma, and habituation: evidence from mobility data.

BACKGROUND: The Japanese government has restricted people's going-out behavior by declaring a non-punitive state of emergency several times under COVID-19. This study aims to analyze how multiple policy interventions that impose non-legally binding restrictions on behavior associate with people's going-out. THEORY: This study models the stigma model of self-restraint behavior under the pandemic with habituation effects. The theoretical result indicates that the state of emergency's self-restraint effects weaken with the number of times. METHODS: The empirical analysis examines the impact of emergency declarations on going-out behavior using a prefecture-level daily panel dataset. The dataset includes Google's going-out behavior data, the Japanese government's policy interventions based on emergency declarations, and covariates that affect going-out behavior, such as weather and holidays. RESULTS: First, for multiple emergency declarations from the beginning of the pandemic to 2021, the negative association between emergency declarations and mobility was confirmed in a model that did not distinguish the number of emergency declarations. Second, in the model that considers the number of declarations, the negative association was found to decrease with the number of declarations. CONCLUSION: These empirical analyses are consistent with the results of theoretical analyses, which show that the negative association between people's going-out behavior and emergency declarations decreases in magnitude as the number of declarations increases.

Fear of progression in patients with mild or common type COVID-19.

AIM: To investigate the current condition and degree of fear of disease progression and associated factors in patients with mild or common type COVID-19. BACKGROUND: At the end of 2019, COVID-19 spread from Wuhan in Hubei Province throughout China. Confirmed cases and deaths have since been reported in many countries around the world. However, fear of progression in these patients has been poorly explored. METHODS: During February 2020, we recruited 114 patients with mild or common type COVID-19 admitted to a Fangcang shelter hospital. We assessed patients' degree of fear using the simplified Fear of Progression Questionnaire (Chinese version). Multiple regression analysis was applied to explore potential factors. RESULTS: The fear of disease progression scores of patients with mild or common COVID-19 was at the low-to-moderate level. Current unemployment, disease duration of 28 days or more and not having a spouse diagnosed with COVID-19 were factors potentially associated with fear of progression. CONCLUSION: With a high prevalence of fear of disease progression in patients with COVID-19, the risk of psychological effects from the pandemic is significant and fear of progression is one of the manifestations. The need for psychological support services for patients should be included in all pandemic and disaster planning.

An edge-driven multi-agent optimization model for infectious disease detection.

This research work introduces a new intelligent framework for infectious disease detection by exploring various emerging and intelligent paradigms. We propose new deep learning architectures such as entity embedding networks, long-short term memory, and convolution neural networks, for accurately learning heterogeneous medical data in identifying disease infection. The multi-agent system is also consolidated for increasing the autonomy behaviours of the proposed framework, where each agent can easily share the derived learning outputs with the other agents in the system. Furthermore, evolutionary computation algorithms, such as memetic algorithms, and bee swarm optimization controlled the exploration of the hyper-optimization parameter space of the proposed framework. Intensive experimentation has been established on medical data. Strong results obtained confirm the superiority of our framework against the solutions that are state of the art, in both detection rate, and runtime performance, where the detection rate reaches 98% for handling real use cases.

A model of COVID-19 propagation based on a gamma subordinated negative binomial branching process.

We build a parsimonious Crump-Mode-Jagers continuous time branching process of COVID-19 propagation based on a negative binomial process subordinated by a gamma subordinator. By focusing on the stochastic nature of the process in small populations, our model provides decision making insight into mitigation strategies as an outbreak begins. Our model accommodates contact tracing and isolation, allowing for comparisons between different types of intervention. We emphasize a physical interpretation of the disease propagation throughout which affords analytical results for comparison to simulations. Our model provides a basis for decision makers to understand the likely trade-offs and consequences between alternative outbreak mitigation strategies particularly in office environments and confined work-spaces. Combining the asymptotic limit of our model with Bayesian hierarchical techniques, we provide US county level inferences for the reproduction number from cumulative case count data over July and August of this year.

Surgical tracheotomy in COVID-19 patients: an Italian single centre experience.

PURPOSE: Coronavirus infection disease 2019 (COVID-19) causes in 10% of patients a severe respiratory distress syndrome managed with invasive mechanical ventilation (IMV), sometimes difficult to wean. The role of tracheotomy is debated for the possible risks for patients and staff. We are going to describe here our experience with surgical tracheotomy in COVID-19 positive patients. METHODS: We enrolled all intensive care unit (ICU) patients requiring longer than 10 days of IMV. Demographic, clinical, respiratory, complications, and outcomes data were collected, in a particular length of weaning from sedation and IMV, in-ICU and in-hospital mortality rate. All healthcare operators involved were tested for SARS-CoV2 by pharyngeal swab and blood test (antibody test). RESULTS: 13 out of 68 ICU patients (19.1%) underwent surgical tracheotomy after a median intubation period of 14 days. The mean age was 60 (56-65) years. 85% were male patients. Postoperative mild bleeding was seen in 30.7%, pneumothorax in 7.7%. Mean weaning from sedation required 3 days, 19 days from IMV. In-ICU and in-hospital COVID-infection-related mortality was 23.1% and 30.7%, respectively. None of the healthcare operators was found SARS-CoV2 positive during the period of the study. CONCLUSIONS: In COVID-19 pandemic surgical tracheotomy enables to wean from sedation and subsequently from IMV in a safe way for both patients and personnel.

Mitochondria as a Cellular Hub in Infection and Inflammation.

Mitochondria are the energy center of the cell. They are found in the cell cytoplasm as dynamic networks where they adapt energy production based on the cell's needs. They are also at the center of the proinflammatory response and have essential roles in the response against pathogenic infections. Mitochondria are a major site for production of Reactive Oxygen Species (ROS; or free radicals), which are essential to fight infection. However, excessive and uncontrolled production can become deleterious to the cell, leading to mitochondrial and tissue damage. Pathogens exploit the role of mitochondria during infection by affecting the oxidative phosphorylation mechanism (OXPHOS), mitochondrial network and disrupting the communication between the nucleus and the mitochondria. The role of mitochondria in these biological processes makes these organelle good targets for the development of therapeutic strategies. In this review, we presented a summary of the endosymbiotic origin of mitochondria and their involvement in the pathogen response, as well as the potential promising mitochondrial targets for the fight against infectious diseases and chronic inflammatory diseases.

Mathematical modeling of COVID-19 spreading with asymptomatic infected and interacting peoples.

In this article we propose a modified compartmental model describing the transmission of COVID-19 in Morocco. It takes account on the asymptomatic people and the strategies involving hospital isolation of the confirmed infected person, quarantine of people contacting them, and home containment of all population to restrict mobility. We establish a relationship between the containment control coefficient c 0 and the basic reproduction number R 0 . Different scenarios are tested with different values of c 0 , for which the stability of a Disease Free Equilibrium point is correlated with the condition linking R 0 and c 0 . A worst scenario in which the containment is not respected in the same way during the period of confinement leads to several rebound in the evolution of the pandemic. It is shown that home containment, if it is strictly respected, played a crucial role in controlling the disease spreading.

Postponing vaccination in children with an infection: a qualitative study among general practitioners and pediatricians.

BACKGROUND: Vaccination postponement is an important contributing factor to low vaccination coverage. The causes of vaccine postponement are numerous, but the presence of viral infection, whether febrile or not, is the most frequent cause. OBJECTIVE: The objective was to explore the factors motivating the practice of vaccination postponement in a child with an infection by general practitioners (GPs) and paediatricians. METHODS: An exploratory qualitative study using semi-directive individual interviews was carried out among GPs and paediatricians in a French region between November 2015 and January 2018. After the interviews were fully transcribed, an analysis of the data was performed using an inductive method derived from the grounded theory. RESULTS: Fourteen GPs and four paediatricians participated in the study. Vaccination postponement during infection in children is rooted in doctors' practices; it is considered a low-risk habit that is shared with parents, and vaccine hesitancy reinforces this practice. In children presenting with an infection, the presence of uncertainty about vaccine safety and effectiveness seems to justify postponing vaccination. The organization of a consultation dedicated to vaccination catch-up was cited as the best tool to limit the effects of vaccination delay on vaccination coverage. DISCUSSION: In children presenting with an infection, vaccination postponement is widely used by GPs and paediatricians. Simplification of the vaccination catch-up process and clear and consistent recommendations on the indications and modalities for vaccination postponement would be useful.

A new modelling of the COVID 19 pandemic.

А model of coronavirus incidence is proposed. Process of disease development is represented as analogue of first- and second order phase transition in physical systems. The model is very simple in terms of the data necessary for the calculations. To verify the proposed model, only data on the current incidence rate are required. However, the determination coefficient of model R2 is very high and exceeds 0.95 for most countries. The model permits the accurate prediction of the pandemics dynamics at intervals of up to 10 days. The ADL(autoregressive distributed lag)-model was introduced in addition to the phase transition model to describe the development of the disease at the exponential phase.The ADL-model allows describing nonmonotonic changes in relative infection over the time, and providing to governments and health care decision makers the possibility to predict the outcomes of their decisions on public health.

The possible role of bacteria, viruses, and parasites in initiation and exacerbation of irritable bowel syndrome.

Irritable bowel syndrome (IBS) is a prolonged and disabling functional gastrointestinal disorder with the incidence rate of 18% in the world. IBS could seriously affect lifetime of patients and cause high economic burden on the community. The pathophysiology of the IBS is hardly understood, whereas several possible mechanisms, such as visceral hypersensitivity, irregular gut motility, abnormal brain-gut relations, and the role of infectious agents, are implicated in initiation and development of this syndrome. Different studies demonstrated an alteration in B-lymphocytes, mast cells (MC), T-lymphocytes, and cytokine concentrations in intestinal mucosa or systemic circulation that are likely to contribute to the formation of the IBS. Therefore, IBS could be developed in those with genetic predisposition. Infections' role in initiation and exacerbation of IBS has been investigated by quite several clinical studies; moreover, the possible role of some pathogens in development and exacerbation of this disease has been described. It appears that the main obligatory pathogens correspond with the IBS disease, Clostridium difficile, Escherichia coli, Mycobacterium avium subspecies paratuberculosis, Campylobacter concisus, Campylobacter jejuni, Chlamydia trachomatis, Helicobacter pylori, Pseudomonas aeruginosa, Salmonella spp, Shigella spp, and viruses, particularly noroviruses. A number of pathogenic parasites (Blastocystis, Dientamoeba fragilis, and Giardia lamblia) may also be involved in the progression and exacerbation of the disease. Based on the current knowledge, the current study concludes that the most common bacterial, viral, and parasitic pathogens may be involved in the development and progression of IBS.

Antagonistic activity of recombinant Lactococcus lactis NZ1330 on the adhesion properties of Escherichia coli causing urinary tract infection.

Death from infectious diseases has caused concerns about increases in the resistance of pathogens, impelling researchers to create novel therapeutic solutions. The management of intestinal tract problems has been the advance use of probiotics in medicine. The aim of this study was evaluate the physicochemical cell surface and adhesion properties of recombinant Lacotococcus lactis NZ1330 containing Ama r 2 gene, followed by the assessment of the antagonistic activity of this strain against the Escherichia coli causing urinary tract infection (UTI) in humans. For this purpose, cloning and expression of Ama r 2 gene were done. Afterwards, acid and bile resistance, which are the primary characteristics of any probiotic, were evaluated. The r-L. lactis NZ1330 was examined for the physicochemical properties of cell surfaces and the adhesion properties against Escherichia coli. Furthermore, the potential of the recombinant strain to adhere to adenocarcinoma intestinal cell line, Caco-2 cells, as well as the antagonistic properties of r-L. lactis NZ1330 against E. coli was investigated. r-L. lactis NZ1330 was capable of surviving at low pH and different concentrations of bile salts. 40.1% hydrophobicity, 36.5% auto-aggregation and 14.4% co-aggregation were observed for this strain. The adhesion level of r-L. lactis NZ1330 was 5.7% which was also confirmed by scanning electron microscopy (SEM). r-L. lactis NZ1330 was able to compete, inhibit and displace the adhesion of Escherichia coli to Caco-2 cells. r-L. lactis NZ1330 was considered to be a reliable probiotic alternative by showing these desirable properties. Results revealed that Ama r 2 gene expression had no effect on the positive probiotic properties of L. lactis NZ1330, proving this strain could be a suitable probiotic host for the expression of this allergen.

Queens stay, workers leave: caste-specific responses to fatal infections in an ant.

BACKGROUND: The intense interactions among closely related individuals in animal societies provide perfect conditions for the spread of pathogens. Social insects have therefore evolved counter-measures on the cellular, individual, and social level to reduce the infection risk. One striking example is altruistic self-removal, i.e., lethally infected workers leave the nest and die in isolation to prevent the spread of a contagious disease to their nestmates. Because reproductive queens and egg-laying workers behave less altruistically than non-laying workers, e.g., when it comes to colony defense, we wondered whether moribund egg-layers would show the same self-removal as non-reproductive workers. Furthermore, we investigated how a lethal infection affects reproduction and studied if queens and egg-laying workers intensify their reproductive efforts when their residual reproductive value decreases ("terminal investment"). RESULTS: We treated queens, egg-laying workers from queenless colonies, and non-laying workers from queenright colonies of the monogynous (single-queened) ant Temnothorax crassispinus either with a control solution or a solution containing spores of the entomopathogenic fungus Metarhizium brunneum. Lethally infected workers left the nest and died away from it, regardless of their reproductive status. In contrast, infected queens never left the nest and were removed by workers only after they had died. The reproductive investment of queens strongly decreased after the treatment with both, the control solution and the Metarhizium brunneum suspension. The egg laying rate in queenless colonies was initially reduced in infected colonies but not in control colonies. Egg number increased again with decreasing number of infected workers. CONCLUSIONS: Queens and workers of the ant Temnothorax crassispinus differ in their reaction to an infection risk and a reduced life expectancy. Workers isolate themselves to prevent contagion inside the colony, whereas queens stay in the nest. We did not find terminal investment; instead it appeared that egg-layers completely shut down egg production in response to the lethal infection. Workers in queenless colonies resumed reproduction only after all infected individuals had died, probably again to minimize the risk of infecting the offspring.

Severity of Respiratory Syncytial Virus Lower Respiratory Tract Infection With Viral Coinfection in HIV-Uninfected Children.

Background: Molecular diagnostics enable sensitive detection of respiratory viruses, but their clinical significance remains unclear in pediatric lower respiratory tract infection (LRTI). We aimed to determine whether viral coinfections increased life-threatening disease in a large cohort. Methods: Molecular testing was performed for respiratory viruses in nasopharyngeal aspirates collected from children aged <5 years within 24 hours of hospital admission during sentinel surveillance for severe acute respiratory illness (SARI) hospitalization conducted in South Africa during February 2009-December 2013. The primary outcome was life-threatening disease, defined as mechanical ventilation, intensive care unit admission, or death. Results: Of 2322 HIV-uninfected children with respiratory syncytial virus (RSV)-associated LRTI, 1330 (57.3%) had RSV monoinfection, 38 (1.6%) had life-threatening disease, 575 (24.8%) had rhinovirus, 347 (14.9%) had adenovirus (ADV), and 30 (1.3%) had influenza virus. RSV and any other viral coinfection was not associated with severe disease, ADV coinfection had increased odds of life-threatening disease (adjusted OR, 3.4; 95% CI, 1.6-7.2; P = .001), and influenza coinfection had increased odds of life-threatening disease and prolonged length of stay (adjusted OR, 2.1; 95% CI, 1.0-4.5; P = .05) compared with RSV monoinfection. Conclusions: RSV coinfection with any respiratory virus is not associated with more severe disease when compared to RSV alone in this study. However, increased life-threatening disease in RSV-ADV and RSV-influenza coinfection warrants further study.

Morphological study of efficacy of clarithromycin-loaded nanocarriers for treatment of biofilm infection disease.

In this study, we developed a drug delivery system (DDS) using polymeric nanocarriers for the treatment of biofilm infection disease. Clarithromycin (CAM)-encapsulated and chitosan (CS) modified polymeric nanoparticles (NPs) were prepared using a polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer (Soluplus®) (Sol) and poly-(DL-lactide-co-glycolide), respectively. To understand the availability of the prepared NPs, we made morphological observations of the antibacterial activity derived from the NPs toward the bacterial cells within the biofilm using scanning electron microscopy and transmission electron microscopy measurements. These results revealed different antibacterial activities for the two types of drug carriers. In the case of CAM-encapsulated + CS-modified Sol micelles treatment, NPs can exert their antibacterial activity not only by the surfactant, CAM and CS effects but also by intrusion into the bacterial cells. Thereby, CAM-encapsulated + CS-modified Sol micelles had a higher antibacterial activity. The morphological information is useful to design suitable NPs for the treatment against biofilm infections.

Opportunities for the development of novel therapies based on host-microbial interactions.

Immune responses are fundamental for protecting against most infectious agents. However, there is now much evidence to suggest that the pathogenesis and tissue damage after infection are not usually related to the direct action of the replication of microorganisms, but instead to altered immune responses triggered after the contact with the pathogen. This review article discusses several mechanisms necessary for the host to protect against microbial infection and focuses in aspects that cause altered inflammation and drive immunopathology. These basic findings can ultimately reveal pathways amenable to host-directed therapy in adjunct to antimicrobial therapy for future improved control measures for many infectious diseases. Therefore, modulating the effects of inflammatory pathways may represent a new therapy during infection outcome and disease.

Glycaemic control is a predictor of infection-related hospitalization on haemodialysis patients: Miyazaki Dialysis Cohort study (MID study).

AIM: Although infection is the second leading cause of death in maintenance haemodialysis patients, the effects of glycaemic control on infection in diabetic haemodialysis patients have not yet been examined in detail. We examined the relationship between diabetes or glycemic control and infection-related hospitalization (IRH) in haemodialysis patients. METHODS: Patients receiving maintenance haemodialysis (n = 1551, 493 diabetic patients) were enrolled in this prospective cohort study in December 2009 and followed-up for 3 years. IRH during the follow-up period was abstracted from medical records. Kaplan-Meier and Cox regression analyses were used to investigate the relationship between diabetes or glycaemic control and IRH. RESULTS: The Kaplan-Meier analysis revealed that the risk of IRH was significantly higher in haemodialysis patients with diabetes, particularly in those with poorly controlled HbA1c levels (HbA1c ≥ 7.0%), than in haemodialysis patients without diabetes. When patients with ≥HbA1c 7.0% were divided into two groups using a median value of HbA1c, the risk of IRH was significantly higher in those with the poorest glycaemic control (HbA1c ≥ 7.4%), an older age, or lower albumin levels. The multivariable-adjusted hazard ratio for the risk of IRH was not higher in the second criteria of HbA1c (HbA1c 7.0-7.3%), but was significantly higher in the group with the poorest glycaemic control (HbA1c ≥ 7.4%) than in those in the good control criterion (HbA1c < 7.0%). CONCLUSIONS: Although diabetes is a risk factor for IRH among maintenance haemodialysis patients, the relationship between glycaemic control and the risk of infection is not linear. Therefore, the risk of infection may increase in a manner that is dependent on the glycaemic control threshold.