Abstract Bacteria rapidly adapt to changes in their environment by leveraging sensing systems that permanently probe their surroundings. One common assumption is that such systems are responsive to signals that are chemical in nature. Yet, bacteria frequently experience changes in mechanical forces, for example as they transition from planktonic to sessile states. Do single bacteria actively sense and respond to mechanical forces? I here briefly review evidence indicating that bacteria actively respond to mechanical stimuli, and along concisely describe their intricate machinery enabling the transduction of force ...
Source: Current Opinion in Microbiology - January 6, 2017 Category: Microbiology Authors: Persat A Tags: Curr Opin Microbiol Source Type: research
Bacteria and endothelial cells: a toxic relationship.
Abstract Pathogenic bacteria use the bloodstream as a highway for getting around the body, and thus have to find ways to enter and exit through the endothelium. Many bacteria approach this problem by producing toxins that can breach the endothelial barrier through diverse creative mechanisms, including directly killing endothelial cells (ECs), weakening the cytoskeleton within ECs, and breaking the junctions between ECs. Toxins can also modulate the immune response by influencing endothelial biology, and can modulate endothelial function by influencing the response of leukocytes. Understanding these interactions, ...
Source: Current Opinion in Microbiology - December 22, 2016 Category: Microbiology Authors: Lubkin A, Torres VJ Tags: Curr Opin Microbiol Source Type: research
The emerging metabolic view of Clostridium difficile pathogenesis.
Abstract It is widely accepted that Clostridium difficile exploits dysbiosis and leverages inflammation to thrive in the gut environment, where it can asymptomatically colonize humans or cause a toxin-mediated disease ranging in severity from frequent watery diarrhea to pseudomembranous colitis or toxic megacolon. Here, we synthesize recent findings from the gut microbiota and enteric pathogenesis fields to inform the next steps toward a better understanding of C. difficile infection (CDI). In this review, we present a model in which the lifestyle of C. difficile is dictated by the metabolic state of the distal gu...
Source: Current Opinion in Microbiology - December 17, 2016 Category: Microbiology Authors: Hryckowian AJ, Pruss KM, Sonnenburg JL Tags: Curr Opin Microbiol Source Type: research
Actin-based motility and cell-to-cell spread of bacterial pathogens.
Abstract Subversion of the host actin cytoskeleton is a critical virulence mechanism used by a variety of intracellular bacterial pathogens during their infectious life cycles. These pathogens manipulate host actin to promote actin-based motility and coordinate motility with cell-to-cell spread. Growing evidence suggests that the tactics employed by pathogens are surprisingly diverse. Here, we review recent advances suggesting that bacterial surface proteins exhibit divergent biochemical mechanisms of actin polymerization and recruit distinct host protein networks to drive motility, and that bacteria deploy secret...
Source: Current Opinion in Microbiology - December 17, 2016 Category: Microbiology Authors: Lamason RL, Welch MD Tags: Curr Opin Microbiol Source Type: research
Autophagic targeting and avoidance in intracellular bacterial infections.
Abstract Eukaryotic cells use autophagy to break down and recycle components such as aggregated proteins and damaged organelles. Research in the past decade, particularly using Salmonella enterica serovar Typhimurium as a model pathogen, has revealed that autophagy can also target invading intracellular bacterial pathogens for degradation. However, many bacterial pathogens have evolved mechanisms that allow for evasion of the autophagic pathway, such as motility or direct and irreversible cleavage of proteins that comprise the autophagic machinery. As a complete and detailed understanding of the autophagic pathway...
Source: Current Opinion in Microbiology - December 13, 2016 Category: Microbiology Authors: Kohler LJ, Roy CR Tags: Curr Opin Microbiol Source Type: research
Viral-bacterial co-infections in the respiratory tract.
Abstract Preceding or concurrent viral respiratory tract infection can predispose to secondary bacterial co-infection throughout the airway. The mechanisms by which viruses promote these superinfections are diverse and replete. Whereas we understand much as to how viruses damage the airway and dysregulate both innate and acquired immune responses which, in turn, supports bacterial growth, adherence and invasion into normally sterile sites within the respiratory tract, new information regarding these co-infections is being gained from recent advances in microbiome research and our enhanced appreciation of the contr...
Source: Current Opinion in Microbiology - December 7, 2016 Category: Microbiology Authors: Bakaletz LO Tags: Curr Opin Microbiol Source Type: research
Bacterial E3 ligase effectors exploit host ubiquitin systems.
Abstract Ubiquitination is a crucial post-translational protein modification involved in regulation of various cellular processes in eukaryotes. In particular, ubiquitination is involved in multiple aspects of bacterial infection and host defense mechanisms. In parallel with the identification of ubiquitination as a component of host defense systems, recently accumulated evidence shows that many bacterial pathogens exploit host ubiquitin systems to achieve successful infection. Here, we highlight the strategies by which bacteria subvert host ubiquitin systems by mimicking E3 ubiquitin ligase activity. PMID: 2...
Source: Current Opinion in Microbiology - November 28, 2016 Category: Microbiology Authors: Ashida H, Sasakawa C Tags: Curr Opin Microbiol Source Type: research
Making a microbiome: the many determinants of host-associated microbial community composition.
Abstract The composition of many host-associated microbial communities is characterized by seemingly contradictory features: strong selection for specific taxa by the host, but substantial variability among hosts and over time within one host. Recent advances have revealed that both deterministic and stochastic processes operating across multiple spatial scales shape the composition of host-associated microbial communities. Although most research has focused on deterministic processes within individual hosts, the microbiota within each host is increasingly recognized to contribute to a wider metacommunity maintain...
Source: Current Opinion in Microbiology - November 28, 2016 Category: Microbiology Authors: Adair KL, Douglas AE Tags: Curr Opin Microbiol Source Type: research
Microbiome, metabolites and host immunity.
Abstract In the intestine, the microbial genomes and repertoire of biochemical reactions outnumber those of the host and significantly contribute to many aspects of the host's health, including metabolism, immunity, development and behavior, while microbial community imbalance is associated with disease. The crosstalk between the host and its microbiome occurs in part through the secretion of metabolites, which have a profound effect on host physiology. The immune system constantly scans the intestinal microenvironment for information regarding the metabolic state of the microbiota as well as the colonization stat...
Source: Current Opinion in Microbiology - November 21, 2016 Category: Microbiology Authors: Levy M, Blacher E, Elinav E Tags: Curr Opin Microbiol Source Type: research
Investigating the cell biology of plant infection by the rice blast fungus Magnaporthe oryzae.
Abstract Rice blast disease is a major constraint on worldwide rice production and understanding the biology of plant infection is a priority for development of new disease control strategies. Recent advances in live cell imaging, coupled with tractability of both host and pathogen to molecular genetics and genomics, has made the rice blast pathosystem an important model for understanding plant disease. Here we review recent advances in understanding the cell biology of plant infection and, in particular, the remarkable ability of the rice blast fungus to invade plant tissue and manipulate the host plant using a b...
Source: Current Opinion in Microbiology - November 3, 2016 Category: Microbiology Authors: Yan X, Talbot NJ Tags: Curr Opin Microbiol Source Type: research
How to invade a susceptible host: cellular aspects of aspergillosis.
Abstract Diseases caused by Aspergillus spp. and in particular A. fumigatus are manifold and affect individuals suffering from immune dysfunctions, among them immunocompromised ones. The determinants of whether the encounter of a susceptible host with infectious propagules of this filamentous saprobe results in infection have been characterized to a limited extent. Several cellular characteristics of A. fumigatus that have evolved in its natural environment contribute to its virulence, among them general traits as well as particular ones that affect interaction with the mammalian host. Among the latter, conidial c...
Source: Current Opinion in Microbiology - November 2, 2016 Category: Microbiology Authors: Krappmann S Tags: Curr Opin Microbiol Source Type: research
The cell biology of late blight disease.
Abstract Late blight, caused by the oomycete Phytophthora infestans, is a major global disease of potato and tomato. Cell biology is teaching us much about the developmental stages associated with infection, especially the haustorium, which is a site of intimate interaction and molecular exchange between pathogen and host. Recent observations suggest a role for the plant endocytic cycle in specific recruitment of host proteins to the Extra-Haustorial Membrane, emphasising the unique nature of this membrane compartment. In addition, there has been a strong focus on the activities of RXLR effectors, which are delive...
Source: Current Opinion in Microbiology - October 7, 2016 Category: Microbiology Authors: Whisson SC, Boevink PC, Wang S, Birch PR Tags: Curr Opin Microbiol Source Type: research
Editorial overview: Growth and development: prokaryotes.
PMID: 27720364 [PubMed - as supplied by publisher] (Source: Current Opinion in Microbiology)
Source: Current Opinion in Microbiology - October 5, 2016 Category: Microbiology Authors: Ramamurthi KS Tags: Curr Opin Microbiol Source Type: research
Cell biology of Candida albicans-host interactions.
Abstract Candida albicans is a commensal coloniser of most people and a pathogen of the immunocompromised or patients in which barriers that prevent dissemination have been disrupted. Both the commensal and pathogenic states involve regulation and adaptation to the host microenvironment. The pathogenic potential can be downregulated to sustain commensalism or upregulated to damage host tissue and avoid and subvert immune surveillance. In either case it seems as though the cell biology of this fungus has evolved to enable the establishment of different types of relationships with the human host. Here we summarise l...
Source: Current Opinion in Microbiology - September 27, 2016 Category: Microbiology Authors: da Silva Dantas A, Lee KK, Raziunaite I, Schaefer K, Wagener J, Yadav B, Gow NA Tags: Curr Opin Microbiol Source Type: research
Regulations governing the multicellular lifestyle of Myxococcus xanthus.
Abstract In living organisms, cooperative cell movements underlie the formation of differentiated tissues. In bacteria, Myxococcus xanthus uses cooperative group movements, to predate on prey and to form multicellular fruiting bodies, where the cells differentiate into dormant spores. Motility is controlled by a central signaling Che-like pathway, Frz. Single cell studies indicate Frz regulates the frequency at which cells reverse their direction of movement by transmitting signals to a molecular system that controls the spatial activity of the motility engines. This regulation is central to all Myxococcus multice...
Source: Current Opinion in Microbiology - September 17, 2016 Category: Microbiology Authors: Mercier R, Mignot T Tags: Curr Opin Microbiol Source Type: research
Redefining the roles of the FtsZ-ring in bacterial cytokinesis.
Abstract In most bacteria, cell division relies on the functions of an essential protein, FtsZ. FtsZ polymerizes at the future division site to form a ring-like structure, termed the Z-ring, that serves as a scaffold to recruit all other division proteins, and possibly generates force to constrict the cell. The scaffolding function of the Z-ring is well established, but the force generating function has recently been called into question. Additionally, new findings have demonstrated that the Z-ring is more directly linked to cell wall metabolism than simply recruiting enzymes to the division site. Here we review t...
Source: Current Opinion in Microbiology - September 9, 2016 Category: Microbiology Authors: Xiao J, Goley ED Tags: Curr Opin Microbiol Source Type: research
How bacterial pathogens use type III and type IV secretion systems to facilitate their transmission.
;umler AJ Abstract Work on type III or type IV secretion systems (T3SSs or T4SSs) is often focused on elucidating how these sophisticated bacterial virulence factors manipulate host cell physiology to cause disease. But to fully understand their role in pathogen biology, it is important to consider whether the morbidity or mortality they trigger is somehow linked to enhancing communicability of the microbe. Recent work on Salmonella enterica and Brucella abortus provide captivating examples of how manipulation of host cells with T3SSs or T4SSs instigates distant downstream consequences that promote spread of the p...
Source: Current Opinion in Microbiology - September 9, 2016 Category: Microbiology Authors: Byndloss MX, Rivera-Chávez F, Tsolis RM, Bäumler AJ Tags: Curr Opin Microbiol Source Type: research
Exploiting the Achilles' heel of membrane trafficking in trypanosomes.
Abstract Pathogenic protozoa are evolutionarily highly divergent from their metazoan hosts, reflected in many aspects of their biology. One particularly important parasite taxon is the trypanosomatids. Multiple transmission modes, distinct life cycles and exploitation of many host species attests to great prowess as parasites, and adaptability for efficient, chronic infection. Genome sequencing has begun uncovering how trypanosomatids are well suited to parasitism, and recent genetic screening and cell biology are revealing new aspects of how to control these organisms and prevent disease. Importantly, several lin...
Source: Current Opinion in Microbiology - September 8, 2016 Category: Microbiology Authors: Zoltner M, Horn D, de Koning HP, Field MC Tags: Curr Opin Microbiol Source Type: research
Editorial overview: Microbial systems biology: systems biology prepares the ground for successful synthetic biology.
PMID: 27568258 [PubMed - as supplied by publisher] (Source: Current Opinion in Microbiology)
Source: Current Opinion in Microbiology - August 24, 2016 Category: Microbiology Authors: Takors R, de Lorenzo V Tags: Curr Opin Microbiol Source Type: research
Editorial overview: Antimicrobials: fighting bacterial infections in the 21st century-thinking outside of the box.
PMID: 27567402 [PubMed - as supplied by publisher] (Source: Current Opinion in Microbiology)
Source: Current Opinion in Microbiology - August 24, 2016 Category: Microbiology Authors: Pucci MJ, Dougherty TJ Tags: Curr Opin Microbiol Source Type: research
Developmental differentiation in Leishmania lifecycle progression: post-transcriptional control conducts the orchestra.
Abstract The successful progression of Leishmania spp. through their lifecycle entails a series of differentiation processes; the proliferative procyclic promastigote forms become quiescent, human-infective metacyclic promastigotes during metacyclogenesis in the sandfly vector, which then differentiate into amastigotes during amastigogenesis in the mammalian host. The progression to these infective forms requires two components: environmental cues and a coordinated cellular response. Recent studies have shown that the Leishmania cellular transformation into mammalian-infective stages is triggered by broad changes ...
Source: Current Opinion in Microbiology - August 23, 2016 Category: Microbiology Authors: De Pablos LM, Ferreira TR, Walrad PB Tags: Curr Opin Microbiol Source Type: research
Protease regulation and capacity during Caulobacter growth.
We describe recent insight into how Caulobacter manages DNA replication and repair through Lon and Clp proteases. Because proteases must manage a broad substrate repertoire there must be methods to compensate for protease saturation and we discuss these scenarios. PMID: 27543838 [PubMed - as supplied by publisher] (Source: Current Opinion in Microbiology)
Source: Current Opinion in Microbiology - August 17, 2016 Category: Microbiology Authors: Vass RH, Zeinert RD, Chien P Tags: Curr Opin Microbiol Source Type: research
New weapons in the Cryptococcus infection toolkit.
Abstract The global burden of fungal infections is unacceptably high. The human fungal pathogen Cryptococcus neoformans causes cryptococcosis and accounts for a significant proportion of this burden. Cryptococci undergo a number of elaborate interactions with their hosts, including survival and proliferation within phagocytes as well as dissemination to the central nervous system and other tissues. In this review we highlight a number of exciting recent advances in the field of cryptococcal biology. In particular we discuss new insights into cryptococcal morphology and its impact on virulence, as well as describin...
Source: Current Opinion in Microbiology - August 11, 2016 Category: Microbiology Authors: Taylor-Smith LM, May RC Tags: Curr Opin Microbiol Source Type: research
An intracellular compass spatially coordinates cell cycle modules in Caulobacter crescentus.
Abstract Cellular functions in Bacteria, such as chromosome segregation and cytokinesis, result from cascades of molecular events operating largely as self-contained modules. Regulated timing of these cellular modules stems from global genetic circuits that allow precise temporal activation with respect to cell cycle progression and cell differentiation. Critically, many of these functions occur at defined locations within the cell, and therefore regulators of each module must communicate to remain coordinated in space. In this perspective, we highlight recent discoveries in Caulobacter crescentus asymmetric cell ...
Source: Current Opinion in Microbiology - August 9, 2016 Category: Microbiology Authors: Lasker K, Mann TH, Shapiro L Tags: Curr Opin Microbiol Source Type: research
Building the bacterial cell wall at the pole.
Abstract Polar growth is the predominant mode of cell wall extension in the Actinobacteria and the alphaproteobacterial clade Rhizobiales. The observation of polar elongation in taxonomically diverse bacteria suggests that polar growth may have evolved independently. Indeed, the regulatory mechanisms governing the assembly of cell wall biosynthesis machinery at the pole are distinct in the Actinobacteria and Rhizobiales. Here we highlight recent advances in our understanding of polar growth mechanisms in bacteria, with an emphasis on Streptomyces and Agrobacterium. This review illustrates that common themes are em...
Source: Current Opinion in Microbiology - August 6, 2016 Category: Microbiology Authors: Howell M, Brown PJ Tags: Curr Opin Microbiol Source Type: research
Cell biology of corn smut disease-Ustilago maydis as a model for biotrophic interactions.
Abstract Ustilago maydis is a well-established model system for biotrophic fungal plant pathogens. The fungus has a dimorphic life cycle with a yeast-like saprophytic phase switching to filamentous, pathogenic growth upon hyphal fusion. Due to its highly differentiated development and the amenability for reverse-genetics U. maydis provides a model system for both fungal cell biology as well as the study of biotrophic plant interaction. The present article highlights key findings in different aspects of cell biology on the corn smut disease and provides an outlook on the most intriguing open questions. PMID: 2...
Source: Current Opinion in Microbiology - August 6, 2016 Category: Microbiology Authors: Matei A, Doehlemann G Tags: Curr Opin Microbiol Source Type: research
Functional requirements of cellular differentiation: lessons from Bacillus subtilis.
Abstract Successful execution of differentiation programs requires cells to assess multitudes of internal and external cues and respond with appropriate gene expression programs. Here, we review how Bacillus subtilis sporulation network deals with these tasks focusing on the lessons generalizable to other systems. With feedforward loops controlling both production and activation of downstream transcriptional regulators, cells achieve ultrasensitive threshold-like responses. The arrangement of sporulation network genes on the chromosome and transcriptional feedback loops allow coordination of sporulation decision w...
Source: Current Opinion in Microbiology - August 5, 2016 Category: Microbiology Authors: Narula J, Fujita M, Igoshin OA Tags: Curr Opin Microbiol Source Type: research
An up-date on Giardia and giardiasis.
SG Abstract Giardia intestinalis is a non-invasive protozoan parasite infecting the upper small intestine causing acute, watery diarrhea or giardiasis in 280 million people annually. Asymptomatic infections are equally common and recent data have suggested that infections even can be protective against other diarrheal diseases. Most symptomatic infections resolve spontaneously but infections can lead to chronic disease and treatment failures are becoming more common world-wide. Giardia infections can also result in irritable bowel syndrome (IBS) and food allergies after resolution. Until recently not much was kno...
Source: Current Opinion in Microbiology - August 5, 2016 Category: Microbiology Authors: Einarsson E, Ma'ayeh S, Svärd SG Tags: Curr Opin Microbiol Source Type: research
Cell division of Streptococcus pneumoniae: think positive!
Abstract Bacterial cell division is achieved by a dynamic protein complex called the divisome. The accurate placement of the divisome, and more specifically that of the tubulin-like protein FtsZ which forms the contractile Z-ring at mid-cell, is finely regulated by different mechanisms tailored to each bacterial class. To give rise to two viable daughter cells with the same genetic heritage and cell shape, Streptococcus pneumoniae uses an original system that relies on the membrane protein MapZ. This system is required for identifying the division site as well as positioning the Z-ring at mid-cell. In addition, Ma...
Source: Current Opinion in Microbiology - August 3, 2016 Category: Microbiology Authors: Garcia PS, Simorre JP, Brochier-Armanet C, Grangeasse C Tags: Curr Opin Microbiol Source Type: research
The motility of Entamoeba histolytica: finding ways to understand intestinal amoebiasis.
Abstract The pathogenic amoeba Entamoeba histolytica is able to migrate within various compartments of the human body. The present article reviews progress in understanding the mechanisms of cell motility in E. histolytica during human intestinal invasion and, in particular, how the three-dimensional characteristics of the environment regulate the parasite's behaviour. The amoeboid mode of migration that applies to E. histolytica's displacements on two-dimensional surfaces is also expected to apply to the three-dimensional environment in the human intestine although several unknown, distinct modalities may be invo...
Source: Current Opinion in Microbiology - August 3, 2016 Category: Microbiology Authors: Aguilar-Rojas A, Olivo-Marin JC, Guillen N Tags: Curr Opin Microbiol Source Type: research
Biogenesis of the Gram-positive bacterial cell envelope.
Abstract The Gram-positive cell envelope serves as a molecular platform for surface display of capsular polysaccharides, wall teichoic acids (WTAs), lipoteichoic acids (LTAs), lipoproteins, surface proteins and pili. WTAs, LTAs, and sortase-assembled pili are a few features that make the Gram-positive cell envelope distinct from the Gram-negative counterpart. Interestingly, a set of LytR-CpsA-Psr family proteins, found in all Gram-positives but limited to a minority of Gram-negative organisms, plays divergent functions, while decorating the cell envelope with glycans. Furthermore, a phylum of Gram-positive bacteri...
Source: Current Opinion in Microbiology - August 3, 2016 Category: Microbiology Authors: Siegel SD, Liu J, Ton-That H Tags: Curr Opin Microbiol Source Type: research
Overloaded and stressed: whole-cell considerations for bacterial synthetic biology.
Abstract The predictability and robustness of engineered bacteria depend on the many interactions between synthetic constructs and their host cells. Expression from synthetic constructs is an unnatural load for the host that typically reduces growth, triggers stresses and leads to decrease in performance or failure of engineered cells. Work in systems and synthetic biology has now begun to address this through new tools, methods and strategies that characterise and exploit host-construct interactions in bacteria. Focusing on work in E. coli, we review here a selection of the recent developments in this area, ...
Source: Current Opinion in Microbiology - August 2, 2016 Category: Microbiology Authors: Borkowski O, Ceroni F, Stan GB, Ellis T Tags: Curr Opin Microbiol Source Type: research
Current state and challenges for dynamic metabolic modeling.
SA Abstract While the stoichiometry of metabolism is probably the best studied cellular level, the dynamics in metabolism can still not be well described, predicted and, thus, engineered. Unknowns in the metabolic flux behavior arise from kinetic interactions, especially allosteric control mechanisms. While the stoichiometry of enzymes is preserved in vitro, their activity and kinetic behavior differs from the in vivo situation. Next to this challenge, it is infeasible to test the interaction of each enzyme with each intracellular metabolite in vitro exhaustively. As a consequence, the whole interacting metabolom...
Source: Current Opinion in Microbiology - July 26, 2016 Category: Microbiology Authors: Vasilakou E, Machado D, Theorell A, Rocha I, Nöh K, Oldiges M, Wahl SA Tags: Curr Opin Microbiol Source Type: research
Sensing new chemicals with bacterial transcription factors.
on JL Abstract Bacteria rely on allosteric transcription factors (aTFs) to sense a wide range of chemicals. The variety of effectors has contributed in making aTFs the most used input system in synthetic biological circuits. Considering their enabling role in biotechnology, an important question concerns the size of the chemical space that can potentially be detected by these biosensors. From digging into the ever changing repertoire of natural regulatory circuits, to advances in aTF engineering, we review here different strategies that are pushing the boundaries of this chemical space. We also review natural and ...
Source: Current Opinion in Microbiology - July 26, 2016 Category: Microbiology Authors: Libis V, Delépine B, Faulon JL Tags: Curr Opin Microbiol Source Type: research
System-level genome editing in microbes.
fai G, Fehér T Abstract The release of the first complete microbial genome sequences at the end of the past century opened the way for functional genomics and systems-biology to uncover the genetic basis of various phenotypes. The surge of available sequence data facilitated the development of novel genome editing techniques for system-level analytical studies. Recombineering allowed unprecedented throughput and efficiency in microbial genome editing and the recent discovery and widespread use of RNA-guided endonucleases offered several further perspectives: (i) previously recalcitrant species became editab...
Source: Current Opinion in Microbiology - July 26, 2016 Category: Microbiology Authors: Csörgő B, Nyerges Á, Pósfai G, Fehér T Tags: Curr Opin Microbiol Source Type: research
Connecting chromosome replication with cell growth in bacteria.
Abstract For bacteria to proliferate they must duplicate their genetic material so that it can be passed to their progeny. This requires that DNA replication is coordinated with cell growth and division. In the natural environment bacterial growth is dynamic and strongly influenced by changes in nutrient availability. Recent studies have found that bacteria utilize a range of regulatory systems, many of them species-specific, to coordinate DNA replication with cell growth. This variability likely reflects the diverse lifestyles of different bacterial types. PMID: 27469316 [PubMed - as supplied by publisher] (...
Source: Current Opinion in Microbiology - July 25, 2016 Category: Microbiology Authors: Murray H Tags: Curr Opin Microbiol Source Type: research
Targeting cell membrane adaptation as a novel antimicrobial strategy.
Abstract Emergence of antibiotic resistance is an example of the incredible plasticity of bacteria to survive in all environments. The search for new antibiotics active against traditional targets is more challenging due not only to the lack of novel natural products to fulfill the current clinical needs against multidrug-resistant (MDR) bacteria, but also for the possible 'collateral' effects on the human microbiota. Thus, non-traditional approaches to combat MDR bacteria have been proposed. Here, we discuss the possibility of targeting the membrane response to the antibiotic attack (cell membrane adaptation) as ...
Source: Current Opinion in Microbiology - July 23, 2016 Category: Microbiology Authors: Tran TT, Miller WR, Shamoo Y, Arias CA Tags: Curr Opin Microbiol Source Type: research
Just in case it rains: building a hydrophobic biofilm the Bacillus subtilis way.
Abstract Over the millennia, diverse species of bacteria have evolved multiple independent mechanisms to structure sessile biofilm communities that confer protection and stability to the inhabitants. The Gram-positive soil bacterium Bacillus subtilis biofilm presents as an architecturally complex, highly hydrophobic community that resists wetting by water, solvents, and biocides. This remarkable property is conferred by a small secreted protein called BslA, which self-assembles into an organized lattice at an interface. In the biofilm, production of BslA is tightly regulated and the resultant protein is secreted i...
Source: Current Opinion in Microbiology - July 23, 2016 Category: Microbiology Authors: Arnaouteli S, MacPhee CE, Stanley-Wall NR Tags: Curr Opin Microbiol Source Type: research
Amino acid biosynthetic routes as drug targets for pulmonary fungal pathogens: what is known and why do we need to know more?
Abstract Amongst 1.5 million fatal mycoses of humans occurring annually , the vast majority involve the human lung as the primary site of pathogenesis, and are derived from organisms which occupy environmental niches. On entry into the respiratory system pathogenic fungi must draw upon metabolic versatility for survival and proliferation as the mammalian lung is a nutritionally limiting environment. The nutritional stresses encountered have exposed vulnerabilities which have long been viewed as potential antifungal targets, since humans lack several of the metabolic pathways which fungi rely upon for pathogenic...
Source: Current Opinion in Microbiology - July 22, 2016 Category: Microbiology Authors: Amich J, Bignell E Tags: Curr Opin Microbiol Source Type: research
Sulfate reduction in microorganisms-recent advances and biotechnological applications.
t C Abstract Sulfur, the least common of the five macroelements, plays an important role in biochemistry due to its ability to be easily reduced or oxidized, leading to a great amount of research concerning sulfur bioconversion. Interestingly, new studies concerning microbial sulfate reduction pathways in the last half decade have become increasingly sparse, indicating that most of the pathways involved have been discovered and studied. Despite this, systems biology approaches to model these pathways are often missing or not used. As the products of microbial sulfate reduction play important roles in the environme...
Source: Current Opinion in Microbiology - July 22, 2016 Category: Microbiology Authors: Rückert C Tags: Curr Opin Microbiol Source Type: research
Filling holes in peptidoglycan biogenesis of Escherichia coli.
Abstract The peptidoglycan cell wall is an essential mesh-like structure in most bacteria. It is built outside the cytoplasmic membrane by polymerizing a disaccharide-pentapeptide into glycan chains that are crosslinked by peptides. The disaccharide-pentapeptide is synthetized as a lipid-linked precursor called lipid II, which is exported across the cytoplasmic membrane so that synthases can make new glycan chains. Growth of the peptidoglycan wall requires careful balancing of synthesis of glycan chains and hydrolysis of the preexisting structure to allow incorporation of new material. Recent studies in Escherichi...
Source: Current Opinion in Microbiology - July 21, 2016 Category: Microbiology Authors: Ruiz N Tags: Curr Opin Microbiol Source Type: research
Where are things inside a bacterial cell?
Abstract Bacterial cells are intricately organized, despite the lack of membrane-bounded organelles. The extremely crowded cytoplasm promotes macromolecular self-assembly and formation of distinct subcellular structures, which perform specialized functions. For example, the cell poles act as hubs for signal transduction complexes, thus providing a platform for the coordination of optimal cellular responses to environmental cues. Distribution of macromolecules is mostly mediated via specialized transport machineries, including the MreB cytoskeleton. Recent evidence shows that RNAs also specifically localize within ...
Source: Current Opinion in Microbiology - July 20, 2016 Category: Microbiology Authors: Govindarajan S, Amster-Choder O Tags: Curr Opin Microbiol Source Type: research
Recognizing and engineering digital-like logic gates and switches in gene regulatory networks.
Abstract A central aim of synthetic biology is to build organisms that can perform useful activities in response to specified conditions. The digital computing paradigm which has proved so successful in electrical engineering is being mapped to synthetic biological systems to allow them to make such decisions. However, stochastic molecular processes have graded input-output functions, thus, bioengineers must select those with desirable characteristics and refine their transfer functions to build logic gates with digital-like switching behaviour. Recent efforts in genome mining and the development of programmable R...
Source: Current Opinion in Microbiology - July 19, 2016 Category: Microbiology Authors: Bradley RW, Buck M, Wang B Tags: Curr Opin Microbiol Source Type: research
Editorial overview: The fungal infection arena in animal and plant hosts: dynamics at the interface.
PMID: 27422760 [PubMed - as supplied by publisher] (Source: Current Opinion in Microbiology)
Source: Current Opinion in Microbiology - July 12, 2016 Category: Microbiology Authors: Thomma BP, Bignell E Tags: Curr Opin Microbiol Source Type: research
Antimicrobial photodynamic inactivation: a bright new technique to kill resistant microbes.
Abstract Photodynamic therapy (PDT) uses photosensitizers (non-toxic dyes) that are activated by absorption of visible light to form reactive oxygen species (including singlet oxygen) that can oxidize biomolecules and destroy cells. Antimicrobial photodynamic inactivation (aPDI) can treat localized infections. aPDI neither causes any resistance to develop in microbes, nor is affected by existing drug resistance status. We discuss some recent developments in aPDI. New photosensitizers including polycationic conjugates, stable synthetic bacteriochlorins and functionalized fullerenes are described. The microbial kill...
Source: Current Opinion in Microbiology - July 12, 2016 Category: Microbiology Authors: Hamblin MR Tags: Curr Opin Microbiol Source Type: research
The expanding regulatory network of STING-mediated signaling.
Abstract The identification and characterization of DNA-sensing pathways has been a subject of intensive investigation for the last decade. This interest, in part, is supported by the fact that the main outcome of DNA-responses is production of type I interferon (IFN-I), which, if produced in excessive amounts, leads to various pathologies. STING (stimulator of interferon genes) is positioned in the center of these responses and is activated either via direct sensing of second messengers or via interaction with upstream sensors of dsDNA. STING mediates responses to pathogens as well as host-derived DNA and is, the...
Source: Current Opinion in Microbiology - July 11, 2016 Category: Microbiology Authors: Surpris G, Poltorak A Tags: Curr Opin Microbiol Source Type: research
Engineering membrane and cell-wall programs for tolerance to toxic chemicals: Beyond solo genes.
Abstract Metabolite toxicity in microbes, particularly at the membrane, remains a bottleneck in the production of fuels and chemicals. Under chemical stress, native adaptation mechanisms combat hyper-fluidization by modifying the phospholipids in the membrane. Recent work in fluxomics reveals the mechanism of how membrane damage negatively affects energy metabolism while lipidomic and transcriptomic analyses show that strains evolved to be tolerant maintain membrane fluidity under stress through a variety of mechanisms such as incorporation of cyclopropanated fatty acids, trans-unsaturated fatty acids, and upregul...
Source: Current Opinion in Microbiology - July 1, 2016 Category: Microbiology Authors: Sandoval NR, Papoutsakis ET Tags: Curr Opin Microbiol Source Type: research
Antisense antimicrobial therapeutics.
Abstract Antisense antimicrobial therapeutics are synthetic oligomers that silence expression of specific genes. This specificity confers an advantage over broad-spectrum antibiotics by avoiding unintended effects on commensal bacteria. The sequence-specificity and short length of antisense antimicrobials also pose little risk to human gene expression. Because antisense antimicrobials are a platform technology, they can be rapidly designed and synthesized to target almost any microbe. This reduces drug discovery time, and provides flexibility and a rational approach to drug development. Recent work has shown that ...
Source: Current Opinion in Microbiology - June 29, 2016 Category: Microbiology Authors: Sully EK, Geller BL Tags: Curr Opin Microbiol Source Type: research
Editorial overview: Host-microbe interactions: parasites: How eukaryotic parasites meet the challenges of life in a host.
PMID: 27372032 [PubMed - as supplied by publisher] (Source: Current Opinion in Microbiology)
Source: Current Opinion in Microbiology - June 29, 2016 Category: Microbiology Authors: Burleigh BA, Boothroyd JC Tags: Curr Opin Microbiol Source Type: research
Alarmin(g) the innate immune system to invasive fungal infections.
Abstract Fungi encounter numerous stresses in a mammalian host, including the immune system, which they must adapt to in order to grow and cause disease. The host immune system tunes its response to the threat level posed by the invading pathogen. We discuss recent findings on how interleukin (IL)-1 signaling is central to tuning the immune response to the virulence potential of invasive fungi, as well as other pathogens. Moreover, we discuss fungal factors that may drive tissue invasion and destruction that regulate IL-1 cytokine release. Moving forward understanding the mechanisms of fungal adaption to the host,...
Source: Current Opinion in Microbiology - June 25, 2016 Category: Microbiology Authors: Caffrey AK, Obar JJ Tags: Curr Opin Microbiol Source Type: research