Summary Culture-independent microbiological techniques have shown a previously unappreciated complexity to the bacterial microbiome of the respiratory tract that forces reconsideration of the ...interactions between host, bacteria, and the pathogenesis of exacerbations of chronic lung disease. The composition of the lung microbiome is determined by microbial immigration, elimination, and relative growth rates of its members. All these factors change dramatically in chronic lung disease and further during exacerbations. Exacerbations lack the features of bacterial infections, including increased bacterial burden and decreased diversity of microbial communities. We propose that exacerbations are occasions of respiratory tract dysbiosis—a disorder of the respiratory tract microbial ecosystem with negative effects on host biology. Respiratory tract dysbiosis provokes a dysregulated host immune response, which in turn alters growth conditions for microbes in airways, promoting further dysbiosis and perpetuating a cycle of inflammation and disordered microbiota. Differences in the composition of baseline respiratory tract microbiota might help to explain the so-called frequent-exacerbator phenotype observed in several disease states, and might provide novel targets for therapeutic intervention.
Numerous studies, dating back nearly a century, have demonstrated that microaspiration is common in healthy, asymptomatic subjects 2-5, and knowledge of the bacterial content of inhaled air is as ...old as germ theory itself 6. Since the first culture-independent report of the healthy lung microbiome 7, more than 30 published studies using molecular techniques for bacterial identification have found evidence of bacteria in the lower airways. ...the community membership of the lung microbiome is altered in disease states.
The Microbiome and the Respiratory Tract Dickson, Robert P; Erb-Downward, John R; Martinez, Fernando J ...
Annual review of physiology,
01/2016, Letnik:
78, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Although the notion that "the normal lung is free from bacteria" remains common in textbooks, it is virtually always stated without citation or argument. The lungs are constantly exposed to diverse ...communities of microbes from the oropharynx and other sources, and over the past decade, novel culture-independent techniques of microbial identification have revealed that the lungs, previously considered sterile in health, harbor diverse communities of microbes. In this review, we describe the topography and population dynamics of the respiratory tract, both in health and as altered by acute and chronic lung disease. We provide a survey of current techniques of sampling, sequencing, and analysis of respiratory microbiota and review technical challenges and controversies in the field. We review and synthesize what is known about lung microbiota in various diseases and identify key lessons learned across disease states.
Although culture-independent techniques have shown that the lungs are not sterile, little is known about the lung microbiome in chronic obstructive pulmonary disease (COPD). We used pyrosequencing of ...16S amplicons to analyze the lung microbiome in two ways: first, using bronchoalveolar lavage (BAL) to sample the distal bronchi and air-spaces; and second, by examining multiple discrete tissue sites in the lungs of six subjects removed at the time of transplantation. We performed BAL on three never-smokers (NS) with normal spirometry, seven smokers with normal spirometry ("healthy smokers", HS), and four subjects with COPD (CS). Bacterial 16 s sequences were found in all subjects, without significant quantitative differences between groups. Both taxonomy-based and taxonomy-independent approaches disclosed heterogeneity in the bacterial communities between HS subjects that was similar to that seen in healthy NS and two mild COPD patients. The moderate and severe COPD patients had very limited community diversity, which was also noted in 28% of the healthy subjects. Both approaches revealed extensive membership overlap between the bacterial communities of the three study groups. No genera were common within a group but unique across groups. Our data suggests the existence of a core pulmonary bacterial microbiome that includes Pseudomonas, Streptococcus, Prevotella, Fusobacterium, Haemophilus, Veillonella, and Porphyromonas. Most strikingly, there were significant micro-anatomic differences in bacterial communities within the same lung of subjects with advanced COPD. These studies are further demonstration of the pulmonary microbiome and highlight global and micro-anatomic changes in these bacterial communities in severe COPD patients.
Summary
The gastrointestinal tract is a mucosal surface constantly exposed to foreign antigens and microbes, and is protected by a vast array of immunologically active structures and cells. ...Epithelial cells directly participate in immunological surveillance and direction of host responses in the gut and can express numerous pattern recognition receptors, including Toll‐like receptor 5 (TLR5), TLR1, TLR2, TLR3, TLR9, and nucleotide oligomerization domain 2, as well as produce chemotactic factors for both myeloid and lymphoid cells following inflammatory stimulation. Within the epithelium and in the underlying lamina propria resides a population of innate lymphoid cells that, following stimulation, can become activated and produce effector cytokines and exert both protective and pathogenic roles during inflammation. Lamina propria dendritic cells play a large role in determining whether the response to a particular antigen will be inflammatory or anti‐inflammatory. It is becoming clear that the composition and metabolic activity of the intestinal microbiome, as a whole community, exerts a profound influence on mucosal immune regulation. The microbiome produces short‐chain fatty acids, polysaccharide A, α‐galactosylceramide and tryptophan metabolites, which can induce interleukin‐22, Reg3γ, IgA and interleukin‐17 responses. However, much of what is known about microbiome–host immune interactions has come from the study of single bacterial members of the gastrointestinal microbiome and their impact on intestinal mucosal immunity. Additionally, evidence continues to accumulate that alterations of the intestinal microbiome can impact not only gastrointestinal immunity but also immune regulation at distal mucosal sites.
The Lung Microbiome during Health and Disease Yagi, Kazuma; Huffnagle, Gary B.; Lukacs, Nicholas W. ...
International journal of molecular sciences,
10/2021, Letnik:
22, Številka:
19
Journal Article
Recenzirano
Odprti dostop
Healthy human lungs have traditionally been considered to be a sterile organ. However, culture-independent molecular techniques have reported that large numbers of microbes coexist in the lung and ...airways. The lungs harbor diverse microbial composition that are undetected by previous approaches. Many studies have found significant differences in microbial composition between during health and respiratory disease. The lung microbiome is likely to not only influence susceptibility or causes of diseases but be affected by disease activities or responses to treatment. Although lung microbiome research has some limitations from study design to reporting, it can add further dimensionality to host-microbe interactions. Moreover, there is a possibility that extending understanding to the lung microbiome with new multiple omics approaches would be useful for developing both diagnostic and prognostic biomarkers for respiratory diseases in clinical settings.
With the rapid growth of Internet of Things (IoT) applications, the classic centralized cloud computing paradigm faces several challenges such as high latency, low capacity and network failure. To ...address these challenges, fog computing brings the cloud closer to IoT devices. The fog provides IoT data processing and storage locally at IoT devices instead of sending them to the cloud. In contrast to the cloud, the fog provides services with faster response and greater quality. Therefore, fog computing may be considered the best choice to enable the IoT to provide efficient and secure services for many IoT users. This paper presents the state-of-the-art of fog computing and its integration with the IoT by highlighting the benefits and implementation challenges. This review will also focus on the architecture of the fog and emerging IoT applications that will be improved by using the fog model. Finally, open issues and future research directions regarding fog computing and the IoT are discussed.
The crustacean order Isopoda (excluding Asellota, crustacean symbionts and freshwater taxa) comprise 3154 described marine species in 379 genera in 37 families according to the WoRMS catalogue. The ...history of taxonomic discovery over the last two centuries is reviewed. Although a well defined order with the Peracarida, their relationship to other orders is not yet resolved but systematics of the major subordinal taxa is relatively well understood. Isopods range in size from less than 1 mm to Bathynomus giganteus at 365 mm long. They inhabit all marine habitats down to 7280 m depth but with few doubtful exceptions species have restricted biogeographic and bathymetric ranges. Four feeding categories are recognised as much on the basis of anecdotal evidence as hard data: detritus feeders and browsers, carnivores, parasites, and filter feeders. Notable among these are the Cymothooidea that range from predators and scavengers to external blood-sucking micropredators and parasites. Isopods brood 10-1600 eggs depending on individual species. Strong sexual dimorphism is characteristic of several families, notably in Gnathiidae where sessile males live with a harem of females while juvenile praniza stages are ectoparasites of fish. Protandry is known in Cymothoidae and protogyny in Anthuroidea. Some Paranthuridae are neotenous. About half of all coastal, shelf and upper bathyal species have been recorded in the MEOW temperate realms, 40% in tropical regions and the remainder in polar seas. The greatest concentration of temperate species is in Australasia; more have been recorded from temperate North Pacific than the North Atlantic. Of tropical regions, the Central Indo-Pacific is home to more species any other region. Isopods are decidedly asymmetrical latitudinally with 1.35 times as many species in temperate Southern Hemisphere than the temperate North Atlantic and northern Pacific, and almost four times as many Antarctic as Arctic species. More species are known from the bathyal and abyssal Antarctic than Arctic GOODS provinces, and more from the larger Pacific than Atlantic oceans. Two areas with many species known are the New Zealand-Kermadec and the Northern North Pacific provinces. Deep hard substrates such as found on seamounts and the slopes are underrepresented in samples. This, the documented numbers of undescribed species in recent collections and probable cryptic species suggest a large as yet undocumented fauna, potentially an order of magnitude greater than presently known.
Aims
To identify nursing care most frequently missed in acute adult inpatient wards and to determine evidence for the association of missed care with nurse staffing.
Background
Research has ...established associations between nurse staffing levels and adverse patient outcomes including in‐hospital mortality. However, the causal nature of this relationship is uncertain and omissions of nursing care (referred as missed care, care left undone or rationed care) have been proposed as a factor which may provide a more direct indicator of nurse staffing adequacy.
Design
Systematic review.
Data Sources
We searched the Cochrane Library, CINAHL, Embase and Medline for quantitative studies of associations between staffing and missed care. We searched key journals, personal libraries and reference lists of articles.
Review Methods
Two reviewers independently selected studies. Quality appraisal was based on the National Institute for Health and Care Excellence quality appraisal checklist for studies reporting correlations and associations. Data were ed on study design, missed care prevalence and measures of association. Synthesis was narrative.
Results
Eighteen studies gave subjective reports of missed care. Seventy‐five per cent or more nurses reported omitting some care. Fourteen studies found low nurse staffing levels were significantly associated with higher reports of missed care. There was little evidence that adding support workers to the team reduced missed care.
Conclusions
Low Registered Nurse staffing is associated with reports of missed nursing care in hospitals. Missed care is a promising indicator of nurse staffing adequacy. The extent to which the relationships observed represent actual failures, is yet to be investigated.
Highlights • The study of the fungal microbiome lags behind our understanding of the bacterial microbiome. • All humans and laboratory animals carry indigenous fungal communities when healthy. • The ...fungal microbiome is significantly smaller than the bacterial microbiome. • The role of the fungal microbiome as a cofactor in disease has likely been underestimated.
PDF
