A titanic drug resistance threat in Cryptococcus neoformans.
Abstract Increasing resistance to frontline antifungals is a growing threat to global health. In the face of high rates of relapse for patients with cryptococcal meningitis and frequent drug resistance in clinical isolates, recent insights into Cryptococcus neoformans morphogenesis and genome plasticity take on new and urgent meaning. Here we review the state of the understanding of mechanisms of drug resistance in the context of host-relevant changes in Cryptococcus morphology and cell ploidy. PMID: 31765991 [PubMed - as supplied by publisher] (Source: Current Opinion in Microbiology)
Source: Current Opinion in Microbiology - November 22, 2019 Category: Microbiology Authors: Zafar H, Altamirano S, Ballou ER, Nielsen K Tags: Curr Opin Microbiol Source Type: research

Engineering enzymatic assembly lines to produce new antibiotics.
inson B Abstract Numerous important therapeutic agents, including widely-used antibiotics, anti-cancer drugs, immunosuppressants, agrochemicals and other valuable compounds, are produced by microorganisms. Many of these are biosynthesised by modular enzymatic assembly line polyketide synthases, non-ribosomal peptide synthetases, and hybrids thereof. To alter the backbone structure of these valuable but difficult to modify compounds, the respective enzymatic machineries can be engineered to create even more valuable molecules with improved properties and/or to bypass resistance mechanisms. In the past, many attempt...
Source: Current Opinion in Microbiology - November 16, 2019 Category: Microbiology Authors: Bozhüyük KA, Micklefield J, Wilkinson B Tags: Curr Opin Microbiol Source Type: research

Molecular regulation of Histoplasma dimorphism.
Abstract Temperature serves as a fundamental signal in biological systems. In some microbial pathogens of humans, mammalian body temperature triggers establishment and maintenance of a developmental program that allows the microbe to survive and thrive in the host. Histoplasma capsulatum is one of a group of fungal pathogens called thermally dimorphic fungi, all of which respond to mammalian body temperature by converting from an environmental mold form that inhabits the soil into a parasitic form that causes disease in the host. It has been known for decades that temperature is a key signal that is sufficient to ...
Source: Current Opinion in Microbiology - November 15, 2019 Category: Microbiology Authors: Sil A Tags: Curr Opin Microbiol Source Type: research

Natural products discovery and potential for new antibiotics.
Abstract Microbial natural products have been one of the most important sources for the discovery of potential new antibiotics. However, the decline in the number of new chemical scaffolds discovered and the rediscovery problem of old known molecules has become a limitation for discovery programs developed by an industry confronted by a lack of incentives and a broken economic model. In contrast, the emergence of multidrug resistance in key pathogens has continued to progress and this issue is compounded by a lack of new antibiotics in development to address most of the difficult to treat infections. Advances in g...
Source: Current Opinion in Microbiology - November 15, 2019 Category: Microbiology Authors: Genilloud O Tags: Curr Opin Microbiol Source Type: research

Reductionist synthetic community approaches in root microbiome research.
Abstract Synthetic community (SynCom) approaches can provide functional and mechanistic insights into how plants regulate their microbiomes, and how the microbiome in turn influences plant growth and health. Microbial cultivation and reconstruction play pivotal roles in this process, which enables researchers to reproducibly investigate the interactions between plants and a major proportion of plant-associated microbes in controlled laboratory conditions. Here, we summarize the emergence, current achievements, and future opportunities for using SynCom experiments in plant microbiome research, with a focus on plant...
Source: Current Opinion in Microbiology - November 14, 2019 Category: Microbiology Authors: Liu YX, Qin Y, Bai Y Tags: Curr Opin Microbiol Source Type: research

Antibiotics: past, present and future.
Abstract The first antibiotic, salvarsan, was deployed in 1910. In just over 100 years antibiotics have drastically changed modern medicine and extended the average human lifespan by 23 years. The discovery of penicillin in 1928 started the golden age of natural product antibiotic discovery that peaked in the mid-1950s. Since then, a gradual decline in antibiotic discovery and development and the evolution of drug resistance in many human pathogens has led to the current antimicrobial resistance crisis. Here we give an overview of the history of antibiotic discovery, the major classes of antibiotics and where they...
Source: Current Opinion in Microbiology - November 13, 2019 Category: Microbiology Authors: Hutchings M, Truman A, Wilkinson B Tags: Curr Opin Microbiol Source Type: research

Microbial associations enabling nitrogen acquisition in plants.
Abstract Large flows of nitrogen between the atmosphere, terrestrial and aquatic ecosystems contribute to the global cycle on Earth. When balanced, this cycle ensures that life at every level can flourish and diversify. However, in the past 50 years, humans have had a large, negative influence on nitrogen cycle pushing it beyond safe boundaries at the global level. Alternative, wholesome strategies are needed for the agricultural systems to achieve sustainability without compromising crop yields. Decades of research in the field of biological nitrogen fixation in symbiotic root nodules paved the way for ambitious ...
Source: Current Opinion in Microbiology - November 13, 2019 Category: Microbiology Authors: Tao K, Kelly S, Radutoiu S Tags: Curr Opin Microbiol Source Type: research

The role of nutrient balance in shaping plant root-fungal interactions: facts and speculation.
Abstract Microbiota colonizing plant roots and their vicinity were shown not to be just random associations, but compose, at least to some extent, host-selected microbial consortia. The plant physiological status, especially the nutrient status, prompts changes in plant morphology and metabolism, which successively imposes a selective pressure on microbial communities. It is well established that a low phosphate status of the host plant activates the molecular machinery underlying the development of mutualistic associations in the host root with arbuscular mycorrhizal fungi (AMF). We hypothesize that the plant&acu...
Source: Current Opinion in Microbiology - November 13, 2019 Category: Microbiology Authors: Fabiańska I, Sosa-Lopez E, Bucher M Tags: Curr Opin Microbiol Source Type: research

Next generation microbiome applications for crop production - limitations and the need of knowledge-based solutions.
Abstract Plants are associated with highly diverse microbiota, which are crucial partners for their host carrying out important functions. Essentially, they are involved in nutrient supply, pathogen antagonism and protection of their host against different types of stress. The potential of microbial inoculants has been demonstrated in numerous studies, primarily under greenhouse conditions. However, field application, for example, as biofertilizer or biocontrol agent, is still a challenge as the applied microorganisms often are not provided in sufficiently high cell numbers, are rapidly outcompeted and cannot esta...
Source: Current Opinion in Microbiology - November 12, 2019 Category: Microbiology Authors: Mitter B, Brader G, Pfaffenbichler N, Sessitsch A Tags: Curr Opin Microbiol Source Type: research

Contribution of bacterial-fungal balance to plant and animal health.
Abstract Surfaces of plants and animals are colonized by complex multi-kingdom microbial communities that comprise prokaryotic (i.e. archaea, bacteria) and eukaryotic (i.e. fungi, protists) microbes. Composition and variation in these multi-kingdom microbial communities are influenced by host and environmental cues that drive microbial community differentiation between host niches. Recent evidence indicates that, beyond these major forces, interactions between microbiota members also contribute to the establishment, the stability, and the resilience of host-associated microbial communities. Particularly, the inter...
Source: Current Opinion in Microbiology - November 12, 2019 Category: Microbiology Authors: Getzke F, Thiergart T, Hacquard S Tags: Curr Opin Microbiol Source Type: research

Crying out for help with root exudates: adaptive mechanisms by which stressed plants assemble health-promoting soil microbiomes.
Abstract Plants employ immunological and ecological strategies to resist biotic stress. Recent evidence suggests that plants adapt to biotic stress by changing their root exudation chemistry to assemble health-promoting microbiomes. This so-called 'cry-for-help' hypothesis provides a mechanistic explanation for previously characterized soil feedback responses to plant disease, such as the development of disease-suppressing soils upon successive cultivations of take all-infected wheat. Here, we divide the hypothesis into individual stages and evaluate the evidence for each component. We review how plant immune resp...
Source: Current Opinion in Microbiology - November 12, 2019 Category: Microbiology Authors: Rolfe SA, Griffiths J, Ton J Tags: Curr Opin Microbiol Source Type: research

Gut mycobiota under scrutiny: fungal symbionts or environmental transients?
Abstract The human gastrointestinal tract is home to a thriving community of microbes including the fungal 'mycobiota'. Although sequencing methodology has enumerated diverse fungal genera within this niche, discerning persistent symbiotic residents from contaminants and purely environmental transients remains a challenge. Recent advances in culturomics and sequencing employing metagenomics, metatranscriptomics and longitudinal studies have begun to reveal a human symbiont 'core mycobiome' that may contribute to human health and disease. Trans-kingdom interactions between the bacterial microbiota and evolution wit...
Source: Current Opinion in Microbiology - November 11, 2019 Category: Microbiology Authors: Fiers WD, Gao IH, Iliev ID Tags: Curr Opin Microbiol Source Type: research

Abundance-occupancy distributions to prioritize plant core microbiome membership.
Abstract Core microbiome members are consistent features of a dataset that are hypothesized to reflect underlying functional relationships with the host. A review of the recent plant-microbiome literature reveals a variety of study-specific approaches used to define the core, which presents a challenge to building a general plant-microbiome framework. Abundance-occupancy distributions, used in macroecology to describe changes in community diversity over space, offer an ecological approach for prioritizing core membership for both spatial and temporal studies. Additionally, neutral models fit to the abundance-occup...
Source: Current Opinion in Microbiology - November 9, 2019 Category: Microbiology Authors: Shade A, Stopnisek N Tags: Curr Opin Microbiol Source Type: research

A brief from the leaf: latest research to inform our understanding of the phyllosphere microbiome.
Abstract The plant leaf surface, or phyllosphere, represents a unique and challenging microbial biome with a diverse and dynamic community of commensal, parasitic, and mutualistic agents of microscopic proportions. This mini-review offers a digest of recently published research dedicated to the study of phyllosphere microbiota, framed in the context of processes and outcomes of microbial community assembly, structure, and (inter)activity in the phyllosphere, with particular focus on the contributions of environment, plant, and microbe, and on the potential benefits of interrogating those contributions at finer res...
Source: Current Opinion in Microbiology - November 7, 2019 Category: Microbiology Authors: Leveau JH Tags: Curr Opin Microbiol Source Type: research

Convergent evolution of signal-structure interfaces for maintaining symbioses.
Abstract Symbiotic microbes are essential to the ecological success and evolutionary diversification of multicellular organisms. The establishment and stability of bipartite symbioses are shaped by mechanisms ensuring partner fidelity between host and symbiont. In this minireview, we demonstrate how the interface of chemical signals and host structures influences fidelity between legume root nodules and rhizobia, Hawaiian bobtail squid light organs and Allivibrio fischeri, and fungus-growing ant crypts and Pseudonocardia. Subsequently, we illustrate the morphological diversity and widespread phylogenetic distribut...
Source: Current Opinion in Microbiology - November 7, 2019 Category: Microbiology Authors: Stubbendieck RM, Li H, Currie CR Tags: Curr Opin Microbiol Source Type: research

Tracing the evolutionary routes of plant-microbiota interactions.
Abstract The microbiota thriving at the root-soil interface plays a crucial role in supporting plant growth, development and health. The interactions between plant and soil microbes can be traced back to the initial plant's colonisation of dry lands. Understanding the evolutionary drivers of these interactions will be key to re-wire them for the benefit of mankind. Here we critically assess recent insights into the evolutionary history of plant-microbiota interactions in natural and agricultural ecosystems. We identify distinctive features, as well as commonalities, of these two distinct scenarios and areas requir...
Source: Current Opinion in Microbiology - November 4, 2019 Category: Microbiology Authors: Escudero-Martinez C, Bulgarelli D Tags: Curr Opin Microbiol Source Type: research

The emerging role of gut microbial metabolism on cardiovascular disease.
Abstract The gut microbiome has been implicated in the progression of cardiovascular diseases (CVD) including hypertension, dyslipidemia, atherosclerosis, thrombosis, heart failure, and ischemic stroke. Metabolomics studies in humans and diverse mouse populations have revealed associations between diet-derived gut bacterial metabolites, including trimethylamine-N-oxide, short-chain fatty acids, and intermediates of aromatic amino acid breakdown, with progression of CVD. Functional studies in animals fed diets of defined composition have been instrumental for establishing causal links between these metabolites, the...
Source: Current Opinion in Microbiology - November 3, 2019 Category: Microbiology Authors: Kasahara K, Rey FE Tags: Curr Opin Microbiol Source Type: research

Timescales of gut microbiome dynamics.
Abstract Vast communities of microorganisms inhabit the gastrointestinal tracts of humans and other animals. Understanding their initial development, fluctuations in composition, stability over long times, and responses to transient perturbations - in other words their dynamics - is important both for gaining basic insights into these ecosystems and for rationally manipulating them for therapeutic ends. Gut microbiome dynamics, however, remain poorly understood. We review here studies of gut microbiome dynamics in the presence and absence of external perturbations, noting especially the long timescales associated ...
Source: Current Opinion in Microbiology - November 2, 2019 Category: Microbiology Authors: Schlomann BH, Parthasarathy R Tags: Curr Opin Microbiol Source Type: research

The internationalization of human microbiome research.
Abstract The human microbiome has now been linked with myriad diseases, yet most of this research has been conducted on American and European populations that make up only 1/6th of the world's population. With growing recognition that human microbiomes differ tremendously across global populations, it is especially important to understand how these compositional differences impact health outcomes. Recent advances in infectious disease and malnutrition research have demonstrated the potential for microbiome-based strategies to address the biggest challenges in global health. This review highlights major advances to...
Source: Current Opinion in Microbiology - November 1, 2019 Category: Microbiology Authors: Porras AM, Brito IL Tags: Curr Opin Microbiol Source Type: research

The mycobiota: fungi take their place between plants and bacteria.
Abstract Eukaryotes host numerous intracellular and associated microbes in their microbiota. Fungi, the so-called Mycobiota, are important members of both human and plant microbiota. Moreover, members of the plant mycobiota host their own microbiota on their surfaces and inside their hyphae. The microbiota of the mycobiota includes mycorrhizal helper bacteria (for mycorrhizal fungi) and fungal endobacteria, which are critical for the fungal host and, as such, likely affect the plant. This review discusses the contribution that these often-overlooked members make to the composition and performance of the plant micr...
Source: Current Opinion in Microbiology - October 22, 2019 Category: Microbiology Authors: Bonfante P, Venice F, Lanfranco L Tags: Curr Opin Microbiol Source Type: research

Harnessing the microbiome to control plant parasitic weeds.
Abstract Microbiomes can significantly expand the genomic potential of plants, contributing to nutrient acquisition, plant growth promotion and tolerance to (a)biotic stresses. Among biotic stressors, root parasitic weeds (RPWs), mainly of the genera Orobanche, Phelipanche and Striga, are major yield-limiting factors of a wide range of staple crops, particularly in developing countries. Here, we provide a conceptual synthesis of putative mechanisms by which soil and plant microbiomes could be harnessed to control RPWs. These mechanisms are partitioned in direct and indirect modes of action and discussed in the con...
Source: Current Opinion in Microbiology - October 22, 2019 Category: Microbiology Authors: Masteling R, Lombard L, de Boer W, Raaijmakers JM, Dini-Andreote F Tags: Curr Opin Microbiol Source Type: research

Scales of persistence: transmission and the microbiome.
Abstract Historically microbiomes have been studied on the scale of the individual host, giving little consideration for the role of extra-host microbial populations in microbiome assembly. However, work in recent years has brought to light the importance of inter-host transmission and its influence on microbiome composition and dynamics. We now appreciate that microbiomes do not exist in isolation, but exchange constituents with the microbial communities of other hosts and the environment. Moving forward, fully understanding the role of transmission in microbiome assembly and dynamics will require a high-resoluti...
Source: Current Opinion in Microbiology - October 16, 2019 Category: Microbiology Authors: Robinson CD, Bohannan BJ, Britton RA Tags: Curr Opin Microbiol Source Type: research

Causes and consequences of biotic interactions within microbiomes.
Abstract An integrative pattern-process-mechanism approach is revealing the roles of biotic interactions in microbiome assembly. Patterns of microbiome diversity observed in metagenomic studies can be partly explained by interaction processes (e.g. competition, facilitation) and underlying molecular or genetic mechanisms (e.g. antibiotic production, nutrient cross-feeding). Exciting opportunities remain to fully understand the significance and generalizability of biotic interactions within microbiomes. Many microbial interactions have been studied by chasing easily quantifiable phenotypes including changes in grow...
Source: Current Opinion in Microbiology - October 15, 2019 Category: Microbiology Authors: Cosetta CM, Wolfe BE Tags: Curr Opin Microbiol Source Type: research

Recoding the metagenome: microbiome engineering in situ.
Abstract Synthetic biology has enabled a new generation of tools for engineering the microbiome, including targeted antibiotics, protein delivery, living biosensors and diagnostics, and metabolic factories. Here, we discuss opportunities and limitations in microbiome engineering, focusing on a new generation of tools for in situ genetic modification of a microbiome that hold particular promise in circumventing these limitations. PMID: 31622928 [PubMed - as supplied by publisher] (Source: Current Opinion in Microbiology)
Source: Current Opinion in Microbiology - October 14, 2019 Category: Microbiology Authors: Whitfill T, Oh J Tags: Curr Opin Microbiol Source Type: research

The impact of Vibrio fischeri strain variation on host colonization.
Abstract Strain-level epidemiology is a key approach to understanding the mechanisms underlying establishment of any host-microbe association. The squid-vibrio light organ symbiosis has proven to be an informative and tractable experimental model in which to discover these mechanisms because it involves only one bacterial species, Vibrio fischeri. In this horizontally transmitted symbiosis, the squid presents nutrients to the bacteria located in a bilobed light-emitting organ, while the symbionts provide bioluminescence to their host. To initiate this association, V. fischeri cells go through several distinct stag...
Source: Current Opinion in Microbiology - October 5, 2019 Category: Microbiology Authors: Bongrand C, Ruby EG Tags: Curr Opin Microbiol Source Type: research

Incorporating functional trade-offs into studies of the gut microbiota.
We present dietary intervention as a case study where trade-offs are likely to be relevant and discuss how the health effects of the modern human diet could be better understood in light of trade-offs. Appreciating microbial functional trade-offs as well as host trade-offs will be necessary to design effective interventions targeting the microbiota and, more generally, to understand the evolution of host-microbe interactions. PMID: 31593869 [PubMed - as supplied by publisher] (Source: Current Opinion in Microbiology)
Source: Current Opinion in Microbiology - October 5, 2019 Category: Microbiology Authors: Reese AT, Kearney SM Tags: Curr Opin Microbiol Source Type: research

Leveraging non-human primates for exploring the social transmission of microbes.
Abstract Host social interactions can provide multiple complex pathways for microbial transmission. Here, we suggest non-human primates as models to study the social transmission of commensal or mutualistic microbes due to their high sociality, wide range of group compositions and dominance structures, and diverse group interactions. Microbial sharing from social interactions can positively impact host health by promoting microbial diversity and influencing immunity. Microbes may also drive their own transmission by shaping host behavior, which could lead to fitness benefits for both microbes and hosts. Variation ...
Source: Current Opinion in Microbiology - October 1, 2019 Category: Microbiology Authors: Kuthyar S, Manus MB, Amato KR Tags: Curr Opin Microbiol Source Type: research

Transitions and transmission: behavior and physiology as drivers of honey bee-associated microbial communities.
Abstract Microbial communities have considerable impacts on animal health. However, only in recent years have the host factors impacting microbiome composition been explored. An increasing wealth of microbiome data in combination with decades of research on behavior, physiology, and development have resulted in the European honey bee (Apis mellifera) as a burgeoning model system for studying the influence of host behavior on the microbiota. Honey bees are eusocial insects which exhibit striking behavioral and physiological differences between castes and life stages. These include changes in social contact, environ...
Source: Current Opinion in Microbiology - September 25, 2019 Category: Microbiology Authors: Miller DL, Parish AJ, Newton IL Tags: Curr Opin Microbiol Source Type: research

Beyond pathogens: microbiota interactions with the plant immune system.
Abstract Plant immune receptors perceive microbial molecules and initiate an array of biochemical responses that are effective against most invaders. The role of the plant immune system in detecting and controlling pathogenic microorganism has been well described. In contrast, much less is known about plant immunity in the context of the wealth of commensals that inhabit plants. Recent research indicates that, just like pathogens, commensals in the plant microbiome can suppress or evade host immune responses. Moreover, the plant immune system has an active role in microbiome assembly and controls microbial homeost...
Source: Current Opinion in Microbiology - September 25, 2019 Category: Microbiology Authors: Teixeira PJP, Colaianni NR, Fitzpatrick CR, Dangl JL Tags: Curr Opin Microbiol Source Type: research

Monocyte-derived dendritic cells in malaria.
li RT Abstract The pathogenesis of malaria is a multifactorial syndrome associated with a deleterious inflammatory response that is responsible for many of the clinical manifestations. While dendritic cells (DCs) play a critical role in initiating acquired immunity and host resistance to infection, they also play a pathogenic role in inflammatory diseases. In our recent studies, we found in different rodent malaria models that the monocyte-derived DCs (MO-DCs) become, transiently, a main DC population in spleens and inflamed non-lymphoid organs. These studies suggest that acute infection with Plasmodium berghei pr...
Source: Current Opinion in Microbiology - September 18, 2019 Category: Microbiology Authors: Hirako IC, Assis PA, Galvão-Filho B, Luster AD, Antonelli LR, Gazzinelli RT Tags: Curr Opin Microbiol Source Type: research

Causes and consequences of a conserved bacterial root microbiome response to drought stress.
We present the hypotheses that drought-induced shifts in plant metabolism may be responsible for the observed monoderm enrichment, and that increased monoderm abundance may promote increased drought tolerance in the host. Finally, we discuss how these recent discoveries may inform ongoing efforts to use microbially mediated strategies to improve crop productivity. PMID: 31454709 [PubMed - as supplied by publisher] (Source: Current Opinion in Microbiology)
Source: Current Opinion in Microbiology - August 24, 2019 Category: Microbiology Authors: Xu L, Coleman-Derr D Tags: Curr Opin Microbiol Source Type: research

Translocation of effector proteins into host cells by Toxoplasma gondii.
Abstract The Apicomplexan parasite, Toxoplasma gondii, is an obligate intracellular organism that must co-opt its host cell to survive. To this end, Toxoplasma parasites introduce a suite of effector proteins from two secretory compartments called rhoptries and dense granules into the host cells. Once inside, these effectors extensively modify the host cell to facilitate parasite penetration, replication and persistence. In this review, we summarize the most recent advances in current understanding of effector translocation from Toxoplasma's rhoptry and dense granule organelles into the host cell, with comparisons...
Source: Current Opinion in Microbiology - August 22, 2019 Category: Microbiology Authors: Rastogi S, Cygan AM, Boothroyd JC Tags: Curr Opin Microbiol Source Type: research

Quorum sensing in African trypanosomes.
Abstract Many microbial eukaryotes exhibit cell-cell communication to co-ordinate group behaviours as a strategy to exploit a changed environment, adapt to adverse conditions or regulate developmental responses. Although best characterised in bacteria, eukaryotic microbes have also been revealed to cooperate to optimise their survival or dissemination. An excellent model for these processes are African trypanosomes, protozoa responsible for important human and animal disease in sub Saharan Africa. These unicellular parasites use density sensing in their mammalian host to prepare for transmission. Recently, the sig...
Source: Current Opinion in Microbiology - August 20, 2019 Category: Microbiology Authors: Rojas F, Matthews KR Tags: Curr Opin Microbiol Source Type: research

Intracellular protozoan parasites: living probes of the host cell surface molecular repertoire.
Abstract Intracellular protozoans co-evolved with their mammalian host cells a range of strategies to cope with the composite and dynamic cell surface features they encounter during migration and infection. Therefore, these single-celled eukaryotic parasites represent a fascinating source of living probes for precisely capturing the dynamic coupling between the membrane and contractile cortex components of the cell surface. Such biomechanical changes drive a constant re-sculpting of the host cell surface, enabling rapid adjustments that contribute to cellular homeostasis. As emphasized in this review, through the ...
Source: Current Opinion in Microbiology - July 23, 2019 Category: Microbiology Authors: Pavlou G, Milon G, Tardieux I Tags: Curr Opin Microbiol Source Type: research

Antibiotic discovery through microbial interactions.
Abstract Microorganisms produce biologically active natural products, some of which are useful as antibiotics and other medicines. A great demand for new antibiotics exists due to the diversity of pathogens and their mechanisms of drug resistance. Antibiotics were discovered as natural metabolites that enable a microorganism to suppress the growth of a competitor. Although the pace of discovery has slowed dramatically, new approaches to identifying antibiotics show promise for the future. Among many modern approaches to discovery, co-culturing different species and understanding the molecular bases of their intera...
Source: Current Opinion in Microbiology - July 22, 2019 Category: Microbiology Authors: Zhang C, Straight PD Tags: Curr Opin Microbiol Source Type: research

Environmental and clinical antibiotic resistomes, same only different.
Abstract The history of antibiotic use in the clinic is one of initial efficacy followed inevitably by the emergence of resistance. Often this resistance is the result of the capture and mobilization of genes that have their origins in environmental reservoirs. Both antibiotic production and resistance are ancient and widely distributed among microbes in the environment. This deep reservoir of resistance offers the opportunity for gene flow into susceptible disease-causing bacteria. Not all resistance genes are equally successfully mobilized, and some dominate in the clinic. The differences and similarities in res...
Source: Current Opinion in Microbiology - July 19, 2019 Category: Microbiology Authors: Wright GD Tags: Curr Opin Microbiol Source Type: research

The evolution and transmission of multi-drug resistant Escherichia coli and Klebsiella pneumoniae: the complexity of clones and plasmids.
Abstract The vast majority of Escherichia coli and Klebsiella pneumoniae isolated from human clinical extra-intestinal infections are now multi-drug resistant (MDR). Extended Spectrum Beta Lactamase (ESBL) carriage in clinical isolates of these bacteria is now commonplace, and carriage of carbapenemases is continuing to increase. MDR is primarily concentrated in a small number of globally disseminated clones, which generally differ between ESBL and carbapenemase carrying-clones in E. coli, but seem to converge in K. pneumoniae. In both species MDR is mediated by acquisition and maintenance of MDR plasmids. The pla...
Source: Current Opinion in Microbiology - July 17, 2019 Category: Microbiology Authors: Dunn SJ, Connor C, McNally A Tags: Curr Opin Microbiol Source Type: research

The impact of arginase activity on virulence factors of Leishmania amazonensis.
Abstract The outcome of Leishmania infection depends on the parasite species and the host immune response. Virulence factors have been extensively studied over the years in an effort to find efficient vaccines and/or treatments for Leishmania infection. Arginase activity in Leishmania has been described as an essential player for the polyamines pathway, impacting parasite replication and infectivity. Considering previous studies showing that the absence of arginase activity leads to low infectivity of Leishmania amazonensis, we reanalyzed transcriptomic data comparing both promastigotes and axenic amastigotes from...
Source: Current Opinion in Microbiology - July 12, 2019 Category: Microbiology Authors: Aoki JI, Laranjeira-Silva MF, Muxel SM, Floeter-Winter LM Tags: Curr Opin Microbiol Source Type: research

Corrigendum to "RiPP antibiotics: biosynthesis and engineering potential" [Curr Opin Microbiol 45 (2018) 61-69].
Corrigendum to "RiPP antibiotics: biosynthesis and engineering potential" [Curr Opin Microbiol 45 (2018) 61-69]. Curr Opin Microbiol. 2019 Jul 11;: Authors: Hudson GA, Mitchell DA PMID: 31303539 [PubMed - as supplied by publisher] (Source: Current Opinion in Microbiology)
Source: Current Opinion in Microbiology - July 11, 2019 Category: Microbiology Authors: Hudson GA, Mitchell DA Tags: Curr Opin Microbiol Source Type: research

Candidalysin: discovery and function in Candida albicans infections.
Abstract Candidalysin is a cytolytic peptide toxin secreted by the invasive form of the human pathogenic fungus, Candida albicans. Candidalysin is critical for mucosal and systemic infections and is a key driver of host cell activation, neutrophil recruitment and Type 17 immunity. Candidalysin is regarded as the first true classical virulence factor of C. albicans but also triggers protective immune responses. This review will discuss how candidalysin was discovered, the mechanisms by which this peptide toxin contributes to C. albicans infections, and how its discovery has advanced our understanding of fungal path...
Source: Current Opinion in Microbiology - July 6, 2019 Category: Microbiology Authors: Naglik JR, Gaffen SL, Hube B Tags: Curr Opin Microbiol Source Type: research

Extracellular vesicles of human pathogenic fungi.
Abstract Extracellular vesicles play a significant role in many aspects of cellular life including cell-to-cell communication, pathogenesis and cancer progression. However very little is known about their role in fungi and we are just at the beginning of understanding their influence on fungal pathophysiology and host-pathogen interactions. Recent findings have revealed a role for fungal vesicles in triggering anti-microbial activities as well as in modulating virulence strategies, suggesting potential new avenues for antifungal therapies. In this review, we summarize our current understanding of fungal extracellu...
Source: Current Opinion in Microbiology - July 4, 2019 Category: Microbiology Authors: Bielska E, May RC Tags: Curr Opin Microbiol Source Type: research

Global epidemiology of emerging Candida auris.
Abstract The discovery in 2009 of a new species of yeast, Candida auris, heralded the arrival of a novel emerging human infectious disease. This review highlights the unique characteristics of C. auris that have lled to it being of public health concern worldwide, namely public health concern, namely its global emergence, its ability to cause nosocomial outbreaks in healthcare settings, its innate and emerging resistance to multiple antifungal drugs and its resilience in the face of hygiene and infection control measures. Genomic epidemiology has identified four emergences of C. auris marked by four clades of the ...
Source: Current Opinion in Microbiology - July 3, 2019 Category: Microbiology Authors: Rhodes J, Fisher MC Tags: Curr Opin Microbiol Source Type: research

Heme-iron acquisition in fungi.
Abstract Heme is a bioavailable source of iron, for which different fungi have evolved several distinct acquisition mechanisms. In the iron-scarce animal host, in particular, microbial pathogens are able to utilize the large heme pool of hemoglobin. The opportunistic pathogenic fungus Candida albicans relies on a cascade of related extracellular soluble and cell wall-anchored hemophores to extract the heme from hemoglobin and to steer it across the cell wall to the plasma membrane, where it is endocytosed into the cell. Recent crystal structure determination of the soluble C. albicans hemophore Csa2 revealed a new...
Source: Current Opinion in Microbiology - June 29, 2019 Category: Microbiology Authors: Roy U, Kornitzer D Tags: Curr Opin Microbiol Source Type: research

Inflammasomes and Leishmania: in good times or bad, in sickness or in health.
Abstract The inflammasomes are multi-molecular platforms that are activated in host cell cytoplasm when the innate immune cells are infected with pathogens or exposed to damage signals. Many independent groups reported that Leishmania infection trigger activation of the NLRP3 inflammasome in macrophages for restriction of intracellular parasite replication. Accordingly, Leishmania can dampen NLRP3 activation as an evasion strategy. In vivo, the NLRP3 inflammasome can promote parasite clearance, but the failure to eliminate parasites in the tissues together with sustained inflammasome activation can promote IL-1&be...
Source: Current Opinion in Microbiology - June 20, 2019 Category: Microbiology Authors: Zamboni DS, Sacks DL Tags: Curr Opin Microbiol Source Type: research

Stronger together? Perspectives on phage-antibiotic synergy in clinical applications of phage therapy.
Abstract Increasingly, clinical infections are becoming recalcitrant or completely resistant to antibiotics treatment and multidrug resistance is rising alarmingly. Patients suffering from infections that used to be treated successfully by antibiotic regimens are running out of the treatment options. Bacteriophage (phage) therapy, long practiced in parts of Eastern Europe and the states of the former Soviet Union, is now being reevaluated as a treatment option complementary to and synergistic with antibiotic treatments. We discuss some current studies that have addressed synergistic killing activity between phages...
Source: Current Opinion in Microbiology - June 18, 2019 Category: Microbiology Authors: Segall AM, Roach DR, Strathdee SA Tags: Curr Opin Microbiol Source Type: research

Genome and transcriptome analyses of Leishmania spp.: opening Pandora's box.
Abstract In the last 30 years, significant advances in genetic manipulation tools along with complete genome and transcriptome sequencing have advanced our understanding of the biology of Leishmania parasites and their interplay with the sand fly and mammalian hosts. High-throughput sequencing in association with CRISPR/Cas9 have prepared the ground for significant advances. Given the richness of the progress made over the last decade, in this article, we focused on the most recent contributions of genome-wide and transcriptome analyses of Leishmania spp., which permit the comparison of life cycle stages, the eval...
Source: Current Opinion in Microbiology - June 15, 2019 Category: Microbiology Authors: Cruz AK, Freitas-Castro F Tags: Curr Opin Microbiol Source Type: research

Fantastic yeasts and where to find them: the hidden diversity of dimorphic fungal pathogens.
Abstract Dimorphic fungal pathogens are a significant cause of human disease worldwide. Notably, the dimorphic fungal pathogens within the order Onygenales are considered primary pathogens, causing disease in healthy hosts. Current changes in taxonomy are underway due to advances in molecular phylogenetics, population genetics, and new emerging dimorphic fungal pathogens causing human disease. In this review, we highlight evolutionary relationships of dimorphic fungal pathogens that cause human disease within the order Onygenales and provide rationale to support increased investment in studies understanding the ev...
Source: Current Opinion in Microbiology - June 7, 2019 Category: Microbiology Authors: Van Dyke MCC, Teixeira MM, Barker BM Tags: Curr Opin Microbiol Source Type: research

Mechanisms of genome evolution in Candida albicans.
Abstract The fungus Candida albicans exists as a prevalent commensal and an important opportunistic pathogen that can infect multiple niches of its human host. Recent studies have examined the diploid genome of C. albicans by performing both short-term microevolution studies and comparative genomics on collections of clinical isolates. Common mechanisms driving genome dynamics include accumulation of point mutations, loss of heterozygosity (LOH) events, large-scale chromosomal rearrangements, and even ploidy change, with important consequences for both drug resistance and host adaptation. Evidence for recombinatio...
Source: Current Opinion in Microbiology - June 5, 2019 Category: Microbiology Authors: Ene IV, Bennett RJ, Anderson MZ Tags: Curr Opin Microbiol Source Type: research

The intersection of host and fungus through the zinc lens.
Abstract In this review, we summarize data regarding the influence of zinc on host defenses to human pathogenic fungi and how the fungus acquires zinc to sustain biological functions. Mammals have evolved several extracellular and intracellular mechanisms to withhold zinc from the fungus. Specific immune cells release zinc binding proteins such as calprotectin to capture the metal and deny it to the fungus. Intracellularly, several zinc binding proteins such as metallothioneins starve the fungus of zinc. The net result in both situations is depriving the fungus of a crucial micronutrient. To combat this struggle, ...
Source: Current Opinion in Microbiology - May 24, 2019 Category: Microbiology Authors: Wilson D, Deepe GS Tags: Curr Opin Microbiol Source Type: research

Candida albicans dwelling in the mammalian gut.
ez JC Abstract The yeast Candida albicans inhabits the gastrointestinal tract of most healthy adults, seemingly living there as a harmless commensal. The fungus on occasion disseminates from the gut to other internal organs causing life-threatening infections. Here, I review some of the most exciting advances in the study of gut colonization by C. albicans in the last few years. These developments highlight the close interplay between C. albicans and cohabiting microbes, the responses that commensal fungi elicit from the mammalian host, and the genetic determinants that allow the fungus to thrive in such a crowded...
Source: Current Opinion in Microbiology - May 24, 2019 Category: Microbiology Authors: Pérez JC Tags: Curr Opin Microbiol Source Type: research