Lattice and Lattice Gas Models for Commensalism: Two Shellfishes in Intertidal Zone

The study of mutual interactions in an intertidal zone is important. We are interested in two sessile shellfishes, mussel (Septifer virgatus: species X) and goose barnacle (Capitulum mitella: species Y). Both species X and Y have similar body sizes, and live in an intertidal zone. Their relation is known to be a kind of commensalism: the survival rate of X increases near the location of Y. In contrast, Y receives no gain from X. In the present paper, we present lattice and lattice gas models for commensalism. The latter is mean-field theory of the former. It is found that the relation of commensalism is not stable. Under certain conditions, the competition prevails between both species;if the density of Y is high, the species X receives a damage originated in the limiting space. Moreover, we find that the basic equation derived by lattice gas model well explains the population dynamics for lattice model.

Co-infection with Neisseria mucosa in a patient with tuberculous otitis media

Tuberculous otitis media(TOM) is a rare manifestation caused by Mycobacterium tuberculosis with low incidence rates among extrapulmonary tuberculosis cases. Diagnosis is often delayed because of the presence of several clinical manifestations and the high prevalence of secondary bacterial infections. Few reports have attributed secondary bacterial infections in patients with TOM to commensal Neisseria. Thus, understanding the pathogenic mechanisms and clinical features of commensal Neisseria is important, considering its recent presentation as an infection-causing pathogen. Neisseria mucosa is a commensal inhabitant in humans and is generally considered non-pathogenic but can cause infection in rare cases. Here, we report an atypical secondary infection caused by Neisseria mucosa in an 81-year-old woman with TOM being treated for pulmonary tuberculosis. Direct purulent otorrhea smear microscopy revealed no acid-fast bacilli using Ziehl-Neelsen staining, whereas the phagocytosis of gram-negative cocci by white blood cells was confirmed using Gram staining. Otorrhea culture revealed the growth of N. mucosa. Subsequently, M. tuberculosis infection in the otorrhea was identified using a culture-based method. Vigilance is critical for the early detection of TOM to prevent further complications. This report raises awareness regarding TOM and provides insight into the pathogenicity of N. mucosa in otitis media.

Differences in the effects and action modes of gut commensals against dextran sulfate sodium-induced intestinal inflammation

Inflammatory bowel disease(IBD)is a complex relapsing inflammatory disease in the gut and is driven by complicated host-gut microbiome interactions.Gut commensals have shown different functions in IBD prevention and treatment.To gain a mechanistic understanding of how different commensals affect intestinal inflammation,we compared the protective effects of 6 probiotics(belonging to the genera Akkermansia,Bifidobacterium,Clostridium,and Enterococcus)on dextran sulfate sodium(DSS)-induced colitis in mice with or without gut microbiota.Anti-inflammatory properties(ratio of interleukin(IL)-10 and IL-12)of these strains were also evaluated in an in vitro mesenteric lymph nodes(MLN)co-culture system.Results showed that 4 probiotics(belonging to the species Bifidobacterium breve,Bifidobacterium bifidum,and Enterococcus faecalis)can alleviate colitis in normal mice.The probiotic strains differed in regulating the intestinal microbiota,cytokines(IL-10,IL-1βand interferon(IFN)-γ),and tight junction function(Zonulin-1 and Occludin).By constrast,Akkermansia muciniphila AH39 and Clostridium butyricum FHuNHHMY49T1 were not protective.Interestingly,B.breve JSNJJNM2 with high anti-inflammatory potential in the MLN model could relieve colitis symptoms in antibiotic cocktail(Abx)-treated mice.Meanwhile,E.faecalis FJSWX25M1induced low levels of cytokines in vitro and showed no beneficial effects.Therefore,we provided insight into the clinical application of probiotics in IBD treatment.

DYNAMIC BEHAVIORS OF A DISCRETE COMMENSALISM SYSTEM

A two species discrete commensalism system is proposed and studied. By the Jury＇s conditions for the stability of second order discrete system, the local stability property of positive equilibrium is investigated; after that, sufficient conditions which ensure the global asymptotic stability of the interior equilibrium are obtained. An example together with its numeric simulation is given to illustrate the feasibility of the main result.

Heat stress in pigs and broilers:role of gut dysbiosis in the impairment of the gut-liver axis and restoration of these effects by probiotics,prebiotics and synbiotics

Heat stress is one of the most challenging stressors for animal production due to high economic losses resulting from impaired animal’s productivity,health and welfare.Despite the fact that all farm animal species are susceptible to heat stress,birds and pigs are particularly sensitive to heat stress due to either lacking or non-functional sweat glands.Con-vincing evidence in the literature exists that gut dysbiosis,a term used to describe a perturbation of commensal gut microbiota,develops in broilers and pigs under heat stress.Owing to the protective role of commensal bacteria for the gut barrier,gut dysbiosis causes a disruption of the gut barrier leading to endotoxemia,which contributes to the typical characteristics of heat stressed broilers and growing and growing-finishing pigs,such as reduced feed intake,decreased growth and reduced lean carcass weight.A substantial number of studies have shown that feeding of probiotics,prebiotics and synbiotics is an efficacious strategy to protect broilers from heat stress-induced gut barrier disruption through altering the gut microbiota and promoting all decisive structural,biochemical,and immunologi-cal elements of the intestinal barrier.In most of the available studies in heat stressed broilers,the alterations of gut microbiota and improvements of gut barrier function induced by feeding of either probiotics,prebiotics or synbiot-ics were accompanied by an improved productivity,health and/or welfare when compared to non-supplemented broilers exposed to heat stress.These findings indicate that the restoration of gut homeostasis and function is a key target for dietary interventions aiming to provide at least partial protection of broilers from the detrimental impact of heat stress conditions.Despite the fact that the number of studies dealing with the same feeding strategy in heat stressed pigs is limited,the available few studies suggest that feeding of probiotics might also be a suitable approach to enhance productivity,health and welfare in pigs kept under heat stress conditions.

Alentiana palinpoda,a new commensal polynoid species from a seamount in the Northwest Pacific Ocean

Alentiana has only one member,A.aurantiaca(Verrill,1885),commensal with sea anemone(Bolocera tuediae).Here,Alentiana palinpoda sp.nov.,a second member in the genus Alentiana(subfamily Lepidastheniinae),a new commensal polynoid is described,based on a specimen collected from a deep-water seamount in the Northwest Pacific Ocean.The new species is characterized by large elytra that completely cover the dorsum and are present in every third segment in the posterior regions.Neuropodia are truncated,with two types of neurochaetae;supraacicular chaetae toothed on one side with a slightly inflated end,and subacicular chaetae that are heavy and smooth;the prechaetal lobe is larger than the postchaetal lobe,with the ventral part rolling upward and backward.

稻鱼鸭的生态效应

本文总结了1986-88年举行的"稻-鱼-鸭"、"稻-鱼"、"稻-鸭"和"稻"(CK)四个处理的田间试验及一系列辅助试验资料,旨在鉴别三种共栖模式的投入、产出和经济、生态效益。结果表明,在低温地区的稻田四周挖沟养鱼、放鸭不仅能提高稻、鱼、鸭蛋的产量和收入,而且还改善了稻田的农业生态环境条件。"稻-鱼-鸭"被认为最佳模式,鸭是最活跃的因素。

Helicobacter pylori:Commensal,symbiont or pathogen?

This review considers the data on Helicobacter pylori(H.pylori),which have been accumulated over 40 years since its description as an etiological factor in gastrointestinal diseases.The majority of modern publications are devoted to the study of the pathogenic properties of the microorganism in the development of chronic gastritis,peptic ulcer disease,and gastric cancer,as well as methods for its eradication.However,in recent years,there have been more and more studies which have suggested that H.pylori has a beneficial,or potentially positive,effect on the human body.The authors have attempted to objectively analyze the information accumulated in the literature on H.pylori.Some studies consider it as one of the recently identified human bacterial pathogens,and special attention is paid to the evidence suggesting that it is probably part of the composition of the human microbiome as a commensal(commensal from French to English is a table companion)or even a symbiont.The presented data discussing the presence or absence of the effect of H.pylori on human health suggest that there is an apparent ambiguity of the problem.The re-assessment of the data available on H.pylori infection is important in order to answer the question of whether it is necessary to create a program of mass H.pylori eradication or to apply a more personalized approach to treating patients with H.pylori-associated gastrointestinal diseases and to perform eradication therapy.

肠的上皮的障碍的主人微生物引起的相互作用和规定工作: 从生理学到病理

The gastrointestinal tract is the largest reservoir of commensal bacteria in the human body, providing nutrients and space for the survival of microbes while concurrently operating mucosal barriers to confine the microbial population. The epithelial cells linked by tight junctions not only physically separate the microbiota from the lamina propria, but also secrete proinflammatory cytokines and reactive oxygen species in response to pathogen invasion and metabolic stress and serve as a sentinel to the underlying immune cells. Accumulating evidence indicates that commensal bacteria are involved in various physiological functions in the gut and microbial imbalances (dysbiosis) may cause pathology. Commensal bacteria are involved in the regulation of intestinal epithelial cell turnover, promotion of epithelial restitution and reorganization of tight junctions, all of which are pivotal for fortifying barrier function. Recent studies indicate that aberrant bacterial lipopolysaccharide-mediated signaling in gut mucosa may be involved in the pathogenesis of chronic inflammation and carcinogenesis. Our perception of enteric commensals has now changed from one of opportunistic pathogens to active participants in maintaining intestinal homeostasis. This review attempts to explain the dynamic interaction between the intestinal epithelium and commensal bacteria in disease and health status.

The oral commensal Streptococcus mitis activates the aryl hydrocarbon receptor in human oral epithelial cells

Streptococcus mitis （S. mitis） is a pioneer commensal bacterial species colonizing many of the surfaces of the oral cavity in healthy individuals. Yet, not much information is available regarding its interaction with the host. We used examination of its transcriptional regulation in oral keratinocytes to elucidate some of its potential roles in the oral cavity. Transcription factor analysis of oral keratinocytes predicted S. mitis.mediated activation of aryl hydrocarbon receptor （AhR）, Activation and functionality of AhR was confirmed through nuclear translocation determined by immunofluorescence microscopy and real-time polymerase chain reaction with reverse transcription analysis of CYPIA1, the hallmark gene for AhR activation. Addition of Streptococcus mutans or Streptococcus gordonfi did not induce CYPIA1 transcription in the keratinocyte cultures. Introduction of an AhR-specific inhibitor revealed that S. mitis-mediated transcription of CXCL2 and CXCL8 was regulated by AhR. Elevated levels of pmstaglandin E2 （enzyme-linked immunosorbent assay） in supernatants from S. mitis-treated oral epithelial cells were also attenuated by inhibition of AhR activity. The observed AhR-regulated activities point to a contribution of S. mitis in the regulation of inflammatory responses and thereby to wound healing in the oral cavity. The concept that the oral commensal microbiota can induce AhR activation is important, also in view of the role that AhR has in modulation of T-cell differentiation and as an anti-inflammatory factor in macrophaees.

Production of corticotropin-releasing factor and urocortin from human monocyte-derived dendritic cells is stimulated by commensal bacteria in intestine

AIM:To examine whether commensal bacteria are a contributing cause of stress-related mucosal inflammation.METHODS:Human peripheral blood monocyte-deriveddendritic cells(MoDCs)were stimulated by commensal bacterial strains,including Escherichia coli,Clostridium clostridioforme,Bacteroides vulgatus(B.vulgatus),Fusobacterium varium(F.varium),and Lactobacillus delbrueckii subsp.bulgaricus.After incubation,corticotropin-releasing factor(CRF)and urocortin 1(UCN1)mRNA in the cells was examined by real-time reverse transcription polymerase chain reaction.Supernatants from the cells were tested for CRF and UCN1 using an enzyme-linked immunosorbent assay.RESULTS:Both CRF and UCN1 were significantly augmented by B.vulgatus and F.varium at both the mRNA and protein levels.In particular,B.vulgatus stimulated human MoDCs,resulting in extremely high levels of CRF and UCN1.CONCLUSION:Stimulation of MoDCs by B.vulgatus and F.varium may be associated with CRF/UCN1-related intestinal disorders,such as irritable bowel syndrome and inflammatory bowel disease.

The commensal consortium of the gut microbiome is associated with favorable responses to anti-programmed death protein 1 (PD-1) therapy in thoracic neoplasms

Objective:Immune checkpoint inhibitors have revolutionized cancer therapy for multiple types of solid tumors,but as expected,a large percentage of patients do not show durable responses.Biomarkers that can predict clinical responses to immunotherapies at diagnosis are therefore urgently needed.Herein,we determined the associations between baseline gut commensal microbes and the clinical treatment efficiencies of patients with thoracic neoplasms during anti-programmed death protein 1(PD-1)therapy.Methods:Forty-two patients with advanced thoracic carcinoma who received anti-PD-1 treatment were enrolled in the study.Baseline and time-serial stool samples were analyzed using 16S ribosomal RNA gene sequencing.Tumor responses,patient progression-free survival,and overall survival were used to measure clinical outcomes.Results:The diversities of the baseline gut microbiota were similar between responders(n=23)and nonresponders(n=19).The relative abundances of the Akkermansiaceae,Enterococcaceae,Enterobacteriaceae,Carnobacteriaceae and Clostridiales Family XI bacterial families were significantly higher in the responder group.These 5 bacterial families acted as a commensal consortium and better stratified patients according to clinical responses(P=0.014).Patients with a higher abundance of commensal microbes had prolonged PFS(P=0.00016).Using multivariable analysis,the abundance of the commensal consortium was identified as an independent predictor of anti-PD-1 immunotherapy in thoracic neoplasms(hazard ratio:0.17;95%confidence interval:0.05–0.55;P=0.003).Conclusions:Baseline gut microbiota may have a critical impact on anti-PD-1 treatment in thoracic neoplasms.The abundance of gut commensal microbes at diagnosis might be useful for the early prediction of anti-PD-1 immunotherapy responses.

Commensal Oral Candida in Asian Cohorts

Samaranayake L. Commensal Oral Candida in Asian Cohorts. International Journal of Oral Science, 1 （1）： 2-5, 2009The oral carriage rate of Candida in healthy humans ranges from 40% to 60%. However for a prolonged period, the oral candidal prevalence in humans was documented essentially using data from studies in the West as their prevalence in inhabitants in different regions of the world,including Asia was not known. Yet, recent reports from a number of studies indicate the quality, quantity and prevalence of oral yeasts differ between Asia and other regions for reason that are still unclear. This mini review on such data from Asian studies on oral carriage of Candida provides another intriguing facet of the behavior of this ubiquitous yeast.

Probiotics in inflammatory bowel disease: Pathophysiological background and clinical applications

Ulcerative colitis and Crohn's disease, collectively termed the inflammatory bowel diseases(IBD), are chronic inflammatory disorders of the gastrointestinal tract. A "dysbiotic" relationship between the commensal gut flora and the intestinal mucosa-associated immune system has been at the core of the pathogenesis of these conditions. Probiotics are "good bacteria" with the ability to benefit the health of the host and their therapeutic application has been studied in IBD. The theoretical basis for such utilization relies upon the ability of probiotic microorganisms to interfere with the dysregulated homeostasis that takes place in IBD and restore the immune-bacterial interaction at the intestinal mucosa. Proposed mechanisms of action include the reconstitution of altered flora composition, enhancement of the integrity of the epithelial barrier, promotion of tolerogenic action by dendritic cells, strengthening of the defensive mechanisms of the innate immunity, and the suppression of pro-inflammatory adaptive immune responses. Despite this abundance of supporting experimental evidence, clinical application of probiotics in IBD has been disappointing. Possible explanations for such discrepancy include the great diversity of microorganisms that fall under the definition of probiotics, the lack of standardization of dosages and administration schemes, the heterogeneity between clinical trials, and the inclusion in the treatment arms of patients with a large variety of clinical phenotypes. Addressing these important issues will be critical for the optimal usage of probiotic-based therapies for patients with IBD.

Effect of Using Mouthwash Solution on Commensal Flora of the Oral Cavity among Female Students in Qassim University

Oral health is the pathway to one’s general health and wellness. Mouthwash is a product used as an adjunct to oral hygiene practices as an antiseptic and antiplaque and antimicrobial agent. The awareness of using mouthwash solution is so limited worldwide. And maybe there’s effect of mouthwash on commensal flora. The aim of this study is to measure the effect of using Mouthwash solution on commensal flora of the oral cavity. In this study, we determined three groups, the first group is considered as a basic group where Female students are not using any mouthwash, the second group used mouthwash twice daily for two weeks, group number three used mouthwash twice weekly. We take cytological sample scraping from oral cavity. All the cytological sections of all groups stained with Papanicolaou stain and examined the slides under the microscope. The study came out with the following results: The basic group that did not use any mouthwash remained unchanged, while the second group, who used mouthwash twice daily, showed a clear epithelial tissue for any bacteria and a clear background. Group number three, who used mouthwash twice a week, showed countable bacteria in epithelial tissue with a clear background. Finally, the study concluded: Cosmetic mouthwash solution has a bad effect on commensal flora if you over used it and leads to killing all your normal flora in oral cavity as much as therapeutic mouthwash will do.

Gut commensal bacteria, Paneth cells and their relations to radiation enteropathy

In steady state, the intestinal epithelium forms an important part of the gut barrier to defend against luminal bacterial attack. However, the intestinal epithelium is compromised by ionizing irradiation due to its inherent selfrenewing capacity. In this process, small intestinal bacterial overgrowth is a critical event that reciprocally alters the immune milieu. In other words, intestinal bacterial dysbiosis induces inflammation in response to intestinal injuries, thus influencing the repair process of irradiated lesions. In fact, it is accepted that commensal bacteria can generally enhance the host radiation sensitivity. To address the determination of radiation sensitivity, we hypothesize that Paneth cells press a critical "button" because these cells are central to intestinal health and disease by using their peptides, which are responsible for controlling stem cell development in the small intestine and luminal bacterial diversity. Herein,the most important question is whether Paneth cells alter their secretion profiles in the situation of ionizing irradiation. On this basis, the tolerance of Paneth cells to ionizing radiation and related mechanisms by which radiation affects Paneth cell survival and death will be discussed in this review. We hope that the relevant results will be helpful in developing new approaches against radiation enteropathy.

New observations-with older ones reviewed-on mass migrations in millipedes based on a recent outbreak on Hachijojima(Izu Islands) of the polydesmid diplopod(Chamberlinius hualienensis,Wang 1956):Nothing appears to make much sense

Mass aggregations and migrations of millipedes despite numerous attempts to find causes for their occurrences are still an enigma. They have been reported from both southern and northern hemisphere countries, from highlands and lowlands of both tropical and temperate regions and they can involve species belonging to the orders Julida and Spirobolida, Polydesmida and Glomerida. According to the main suggestions put forward in the past, mass occurrences in Diplopoda occur：（1） because of a lack of food and a population increase beyond sustainable levels;（2） for the purpose of reproduction and in order to locate suitable oviposition sites;（3） to find overwintering or aestivation sites;（4） because of habitat disruption and changes in the local environment;（5） as a consequence of weather conditions the year（or winter and spring） before. A recent outbreak（November 2014） of a mass migration of the polydesmid Chamberlinius hualienensis Wang 1956 on the Japanese Izu Island of Hachijojima 300 km to the south of Tokyo gave this author an opportunity to review the existing literature on millipede mass migrations and to carry out additional observations on the phenomenon in the field as well as the laboratory. Hitherto unreported heavy infestations with phoretic deutonymphs of the mite Histiostoma sp. as well as dense populations of internal rhabditid nematodes（Oscheius cf. necromena and an unidentified species of the genus Fictor）, suggest that infestations of this kind could be necromenic and either have been a contributing factor for the mass migration or been a consequence of so manyindividuals occurring together at close proximity. It is concluded that mass migrations and aggregations in millipedes do not have one common cause, but represent phenomena that often are seasonally recurring events and appear identical in their outcome, but which have evolved as responses to different causes in different millipede taxa and therefore need to be examined on a case-to-case basis.

Sub-acute endocarditis by Corynebacterium straitum : An often ignored pathogen

With the emergence of novel etiologic organisms, panresistance, and invasive medical care infective endocarditis continues to be evasive, requiring newer approaches and modified treatment guidelines. Presented here is the case of a 75-year-old male with history of systolic heart failure with an automatic internal cardioverter defibrillator(AICD) implantation and a prosthetic mitral valve who presented with generalized malaise and progressive shortness of breath for 6 d. He was found to have positive blood cultures for gram positive rod shaped bacteria identified as Corynebacterium straitum, but was not considered as the etiological pathogen initially as it a usual skin contaminant. Later this bacterium was found to be the causative agent for the patient's endocarditis. This case highlights the importance of identifying the role of this uncommon commensal in invasive disease. With the use of effective antibiotic regimen and awareness of these new pathogens in invasive disease, mortality and morbidity can be prevented with initiation of early appropriate therapy.

Commensal <i>E. Coli</i>Strains Uniquely Alter the ECM Topography Independent of Colonic Epithelial Cells

The relationship between commensal bacteria and the epithelial cells lining the colon is normally symbiotic. However, in the setting of diseases which lead to a loss of the protective mucosal layer such as inflammatory bowel disease or colon cancer, commensal bacteria gain the ability to alter both the behavior of epithelial cells as well as their surrounding extra cellular matrix (ECM). While much work has been done to understand the effects of bacteria on diseased epithelial cells in the colon, very little has been done to understand their impact on the ECM. In our previous work, we have shown that topographical changes in the ECM on the luminal side of the colon have a profound influence on the behavior of colonic epithelial cells. However, we do not understand all of the mechanisms that lead to changes in the ECM topography. This study aimed to understand the role that commensal E. coli strains play in altering the ECM topography of type-1 collagen scaffolds. To do this, 1.2 mg/ml type 1 collagen scaffolds were infected with various commensal bacterial strains. At 24 hours post-infection collagen fiber dimensions and substrate topography were determined using standard molecular biology techniques and advanced imaging. Intriguingly, all of the commensal E. coli strains showed some form of substrate degradation. Especially in the case of commensal E. coli strain HS4, maximum nano-scaled protrusions were observed. This data suggests, for the first time, that studying the effects of bacteria alone on the ECM may be critical to improving our understanding of how the cellular microenvironment changes in both health and disease.

Microbiota,renal disease and renal transplantation

Aim of this frontier review has been to highlight the role of microbiota in healthy subjects and in patients affected by renal diseases with particular reference to renal transplantation.The microbiota has a relevant role in conditioning the healthy status and the diseases.In particular gut microbiota is essential in the metabolism of food and has a relevant role for its relationship with the immune system.The indigenous microbiota in patients with chronic renal failure is completely different than that of the healthy subjects and pathobionts appear.This abnormality in microbiota composition is called dysbiosis and may cause a rapid deterioration of the renal function both for activating the immune system and producing large quantity of uremic toxins.Similarly,after renal transplantation the microbiota changes with the appearance of pathobionts,principally in the first period because of the assumption of immunosuppressive drugs and antibiotics.These changes may deeply interfere with the graft outcome causing acute rejection,renal infections,diarrhea,and renal interstitial fibrosis.In addition,change in the microbiota may modify the metabolism of immunosuppressive drugs causing in some patients the need of modifying the immunosuppressant dosing.The restoration of the indigenous microbiota after transplantation is important,either to avoiding the complications that impair the normal renal graft,and because recent studies have documented the role of an indigenous microbiota in inducing tolerance towards the graft.The use of prebiotics,probiotics,smart bacteria and diet modification may restore the indigenous microbiota,but these studies are just at their beginning and more data are needed to draw definitive conclusions.