Too much of a good thing: regulated depletion of c-di-AMP in the bacterial cytoplasm.
Abstract Bacteria that synthesize c-di-AMP also encode several mechanisms for controlling c-di-AMP levels within the cytoplasm. One major class of phosphodiesterases comprises GdpP and DhhP homologs, which degrade c-di-AMP into the linear molecule 5'-pApA or AMP by the DHH-DHHA1 domain. The other major class comprises PgpH homologs, which degrade c-di-AMP by the HD domain. Both GdpP and PgpH harbor sensory domains, likely to regulate c-di-AMP hydrolysis activity in response to signal input. As another possible mechanism for controlling cytoplasmic c-di-AMP levels, bacteria also secrete c-di-AMP via multidrug resis...
Source: Current Opinion in Microbiology - January 7, 2016 Category: Microbiology Authors: Huynh TN, Woodward JJ Tags: Curr Opin Microbiol Source Type: research

The unmasking of 'junk' RNA reveals novel sRNAs: from processed RNA fragments to marooned riboswitches.
Abstract While the notion that RNAs can function as regulators dates back to early molecular studies of gene regulation of the lac operon, it is only over the last decade that the ubiquity and diversity of regulatory RNAs are being realized. Advancements in high throughput sequencing and the adoption of these approaches to rapidly sequence genomes and transcriptomes and to examine gene expression and RNA binding protein specificity have revealed an ever-expanding RNA world. In this review, we focus on recent studies revealing that RNA fragments cleaved from larger coding or noncoding RNAs can have regulatory funct...
Source: Current Opinion in Microbiology - January 6, 2016 Category: Microbiology Authors: De Lay NR, Garsin DA Tags: Curr Opin Microbiol Source Type: research

Bacterial chemotaxis: information processing, thermodynamics, and behavior.
Abstract Escherichia coli has long been used as a model organism due to the extensive experimental characterization of its pathways and molecular components. Take chemotaxis as an example, which allows bacteria to sense and swim in response to chemicals, such as nutrients and toxins. Many of the pathway's remarkable sensing and signaling properties are now concisely summarized in terms of design (or engineering) principles. More recently, new approaches from information theory and stochastic thermodynamics have begun to address how pathways process environmental stimuli and what the limiting factors are. However, ...
Source: Current Opinion in Microbiology - December 27, 2015 Category: Microbiology Authors: Micali G, Endres RG Tags: Curr Opin Microbiol Source Type: research

Type VI secretion and anti-host effectors.
Abstract Secretion systems play a central role in infectious diseases by enabling pathogenic bacteria to deliver virulence factors into target cells. The type VI secretion system (T6SS) mediates bacterial antagonism in various environments including eukaryotic niches, such as the gut. This molecular machine injects lethal toxins directly in target bacterial cells. It provides an advantage to pathogens encountering the commensal flora of the host and indirectly contributes to colonization and persistence. Yet, the T6SS is not employed for the sole purpose of bacterial killing and several T6SS effectors are dedicate...
Source: Current Opinion in Microbiology - December 23, 2015 Category: Microbiology Authors: Hachani A, Wood TE, Filloux A Tags: Curr Opin Microbiol Source Type: research

Unifying view of stem-loop hairpin RNA as origin of current and ancient parasitic and non-parasitic RNAs, including in giant viruses.
Abstract Putatively, stem-loop RNA hairpins explain networks of selfish elements and RNA world remnants. Their genomic density increases with intracellular lifestyle, especially when comparing giant viruses and their virophages. RNA protogenomes presumably templated for mRNAs and self-replicating stem-loops, ancestors of modern genes and parasitic sequences, including tRNAs and rRNAs. Primary and secondary structure analyses suggest common ancestry for t/rRNAs and parasitic RNAs, parsimoniously link diverse RNA metabolites (replication origins, tRNAs, ribozymes, riboswitches, miRNAs and rRNAs) to parasitic RNAs (r...
Source: Current Opinion in Microbiology - December 21, 2015 Category: Microbiology Authors: Seligmann H, Raoult D Tags: Curr Opin Microbiol Source Type: research

Legionella pneumophila, armed to the hilt: justifying the largest arsenal of effectors in the bacterial world.
Abstract Many bacterial pathogens use dedicated translocation systems to deliver arsenals of effector proteins to their hosts. Once inside the host cytosol, these effectors modulate eukaryotic cell biology to acquire nutrients, block microbial degradation, subvert host defenses, and enable pathogen transmission to other hosts. Among all bacterial pathogens studied to date, the gram-negative pathogen, Legionella pneumophila, maintains the largest arsenal of effectors, with over 330 effector proteins translocated by the Dot/Icm type IVB translocation system. In this review, I will discuss some of the recent work on ...
Source: Current Opinion in Microbiology - December 19, 2015 Category: Microbiology Authors: Ensminger AW Tags: Curr Opin Microbiol Source Type: research

Commensal 'trail of bread crumbs' provide pathogens with a map to the intestinal landscape.
Abstract Growth of a microorganism in a host is essential for infection, and bacterial pathogens have evolved to utilize specific metabolites to enhance replication in vivo. Now, emerging data demonstrate that pathogens rely on microbiota-derived metabolites as a form of bacterial-bacterial communication to gain information about location within a host and modify virulence gene expression accordingly. Thus, metabolite-sensing is critical for pathogens to establish infection. Here, we highlight recent examples of how the foodborne pathogen enterohemorrhagic Escherichia coli O157:H7 (EHEC) exploits microbiota-derive...
Source: Current Opinion in Microbiology - December 17, 2015 Category: Microbiology Authors: Luzader DH, Kendall MM Tags: Curr Opin Microbiol Source Type: research

Reprint of "Prospects for the gliding mechanism of Mycoplasma mobile".
Reprint of "Prospects for the gliding mechanism of Mycoplasma mobile". Curr Opin Microbiol. 2015 Dec 17; Authors: Miyata M, Hamaguchi T Abstract Mycoplasma mobile forms gliding machinery at a cell pole and glides continuously in the direction of the cell pole at up to 4.5μm per second on solid surfaces such as animal cells. This motility system is not related to those of any other bacteria or eukaryotes. M. mobile uses ATP energy to repeatedly catch, pull, and release sialylated oligosaccharides on host cells with its approximately 50-nm long legs. The gliding machinery is a large structu...
Source: Current Opinion in Microbiology - December 17, 2015 Category: Microbiology Authors: Miyata M, Hamaguchi T Tags: Curr Opin Microbiol Source Type: research

Infection in an aging population.
Abstract The global population is rapidly aging. Currently, 566 million people are ≥65 years old worldwide, with estimates of nearly 1.5 billion by 2050, particularly in developing countries. Infections constitute a third of mortality in people ≥65 years old. Moreover, lengthening life spans correlate with increased time in hospitals or long-term care facilities and exposure to drug-resistant pathogens. Indeed, the risk of nosocomial infections increases with age, independent of duration spent in healthcare facilities. In this review, we summarize our understanding of how the aging immune system relates to b...
Source: Current Opinion in Microbiology - December 10, 2015 Category: Microbiology Authors: Kline KA, Bowdish DM Tags: Curr Opin Microbiol Source Type: research

Yersinia versus host immunity: how a pathogen evades or triggers a protective response.
Abstract The human pathogenic Yersinia species cause diseases that represent a significant source of morbidity and mortality. Despite this, specific mechanisms underlying Yersinia pathogenesis and protective host responses remain poorly understood. Recent studies have shown that Yersinia disrupt cell death pathways, perturb inflammatory processes and exploit immune cells to promote disease. The ensuing host responses following Yersinia infection include coordination of innate and adaptive immune responses in an attempt to control bacterial replication. Here, we highlight current advances in our understanding of th...
Source: Current Opinion in Microbiology - November 26, 2015 Category: Microbiology Authors: Chung LK, Bliska JB Tags: Curr Opin Microbiol Source Type: research

Regulation of competence-mediated horizontal gene transfer in the natural habitat of Vibrio cholerae.
Abstract The human pathogen Vibrio cholerae is an autochthonous inhabitant of aquatic environments where it often interacts with zooplankton and their chitinous molts. Chitin induces natural competence for transformation in V. cholerae, a key mode of horizontal gene transfer (HGT). Recent comparative genomic analyses were indicative of extensive HGT in this species. However, we can still expand our understanding of the complex regulatory network that drives competence in V. cholerae. Here, we present recent advances, including the elucidation of bipartite competence regulation mediated by QstR, the inclusion of th...
Source: Current Opinion in Microbiology - November 23, 2015 Category: Microbiology Authors: Metzger LC, Blokesch M Tags: Curr Opin Microbiol Source Type: research

Dual role of arginine metabolism in establishing pathogenesis.
This article sheds light upon the roles of arginine metabolism during pathological conditions and its therapeutic potential. PMID: 26610300 [PubMed - as supplied by publisher] (Source: Current Opinion in Microbiology)
Source: Current Opinion in Microbiology - November 20, 2015 Category: Microbiology Authors: Gogoi M, Datey A, Wilson KT, Chakravortty D Tags: Curr Opin Microbiol Source Type: research

Of guards, decoys, baits and traps: pathogen perception in plants by type III effector sensors.
Abstract Effector-triggered immunity (ETI) is conferred by dominant plant resistance (R) genes, which encode predominantly nucleotide-binding and leucine-rich repeat domain proteins (NLRs), against cognate microbial avirulence (Avr) genes, which include bacterial type III secreted effectors (T3Es). The 'guard model' describes the mechanism of T3E perception by plants, whereby NLRs monitor host proteins ('sensors') for T3E-induced perturbations. This model has provided a molecular framework to understand T3E perception and has rationalized how plants can use a limited number of NLRs (∼160 in Arabidopsis) to con...
Source: Current Opinion in Microbiology - November 18, 2015 Category: Microbiology Authors: Khan M, Subramaniam R, Desveaux D Tags: Curr Opin Microbiol Source Type: research

Motility in the epsilon-proteobacteria.
Abstract The epsilon-proteobacteria are a widespread group of flagellated bacteria frequently associated with either animal digestive tracts or hydrothermal vents, with well-studied examples in the human pathogens of Helicobacter and Campylobacter genera. Flagellated motility is important to both pathogens and hydrothermal vent members, and a number of curious differences between the epsilon-proteobacterial and enteric bacterial motility paradigms make them worthy of further study. The epsilon-proteobacteria have evolved to swim at high speed and through viscous media that immobilize enterics, a phenotype that may...
Source: Current Opinion in Microbiology - November 16, 2015 Category: Microbiology Authors: Beeby M Tags: Curr Opin Microbiol Source Type: research

Editorial overview: Growth and development-prokaryotes.
PMID: 26570990 [PubMed - as supplied by publisher] (Source: Current Opinion in Microbiology)
Source: Current Opinion in Microbiology - November 10, 2015 Category: Microbiology Authors: Kearns DB Tags: Curr Opin Microbiol Source Type: research

Diverse mechanisms for inflammasome sensing of cytosolic bacteria and bacterial virulence.
Abstract The inflammasomes are emerging cytosolic defenses against bacterial infections. The inflammasomes converge on inflammatory caspases activation that triggers pyroptosis, and interleukin-1β/18 maturation in the case of caspase-1 activation. The inflammasomes not only detect major bacterial molecules but also sense bacterial virulence activity. Among the canonical caspase-1-activating inflammasomes, the NAIP subfamily of NLR proteins serves as the receptors for bacterial flagellin and type III secretion apparatus; Pyrin indirectly senses Rho modification/inactivation by various bacterial agents; NLRP1 i...
Source: Current Opinion in Microbiology - November 9, 2015 Category: Microbiology Authors: Zhao Y, Shao F Tags: Curr Opin Microbiol Source Type: research

Chewing the fat: lipid metabolism and homeostasis during M. tuberculosis infection.
Abstract The interplay between Mycobacterium tuberculosis lipid metabolism, the immune response and lipid homeostasis in the host creates a complex and dynamic pathogen-host interaction. Advances in imaging and metabolic analysis techniques indicate that M. tuberculosis preferentially associates with foamy cells and employs multiple physiological systems to utilize exogenously derived fatty-acids and cholesterol. Moreover, novel insights into specific host pathways that control lipid accumulation during infection, such as the PPARγ and LXR transcriptional regulators, have begun to reveal mechanisms by which ...
Source: Current Opinion in Microbiology - November 3, 2015 Category: Microbiology Authors: Lovewell RR, Sassetti CM, VanderVen BC Tags: Curr Opin Microbiol Source Type: research

The Type IVB secretion system: an enigmatic chimera.
Abstract Type IV secretion systems (T4SSs) are transporters that span the bacterial inner and outer membranes and deliver substrate biomolecules, including proteins and DNAs, into cells. Recent progress in structural analyses of conjugative plasmid-encoded type IVA secretion systems (T4ASSs) has revealed a unique molecular architecture. The essential virulence system, the Dot/Icm Type IVB secretion system (T4BSS) encoded by the intracellular bacterial pathogen Legionella pneumophila is distantly related to T4ASSs. Molecular and structural analyses of the Dot/Icm T4BSS have provided insights into the mechanisms of ...
Source: Current Opinion in Microbiology - October 31, 2015 Category: Microbiology Authors: Kubori T, Nagai H Tags: Curr Opin Microbiol Source Type: research

Spirochetal motility and chemotaxis in the natural enzootic cycle and development of Lyme disease.
Abstract Two-thirds of all bacterial genomes sequenced to-date possess an organelle for locomotion, referred to as flagella, periplasmic flagella or type IV pili. These genomes may also contain a chemotaxis-signaling system which governs flagellar rotation, thus leading a coordinated function for motility. Motility and chemotaxis are often crucial for infection or disease process caused by pathogenic bacteria. Although motility-associated genes are well-characterized in some organisms, the highly orchestrated synthesis, regulation, and assembly of periplasmic flagella in spirochetes are just being delineated. Rece...
Source: Current Opinion in Microbiology - October 27, 2015 Category: Microbiology Authors: Motaleb MA, Liu J, Mark Wooten R Tags: Curr Opin Microbiol Source Type: research

Prospects for the gliding mechanism of Mycoplasma mobile.
Abstract Mycoplasma mobile forms gliding machinery at a cell pole and glides continuously in the direction of the cell pole at up to 4.5μm per second on solid surfaces such as animal cells. This motility system is not related to those of any other bacteria or eukaryotes. M. mobile uses ATP energy to repeatedly catch, pull, and release sialylated oligosaccharides on host cells with its approximately 50-nm long legs. The gliding machinery is a large structure composed of huge surface proteins and internal jellyfish-like structure. This system may have developed from an accidental combination between an adhesin an...
Source: Current Opinion in Microbiology - October 20, 2015 Category: Microbiology Authors: Miyata M, Hamaguchi T Tags: Curr Opin Microbiol Source Type: research

Undiscovered regions on the molecular landscape of flagellar assembly.
Abstract The bacterial flagellum is a motility structure and one of the most complicated motors in the biosphere. A flagellum consists of several dozens of building blocks in different stoichiometries and extends from the cytoplasm to the extracellular space. Flagellar biogenesis follows a strict spatio-temporal regime that is guided by a plethora of flagellar assembly factors and chaperones. The goal of this review is to summarize our current structural and mechanistic knowledge of this intricate process and to identify the undiscovered regions on the molecular landscape of flagellar assembly. PMID: 26490009...
Source: Current Opinion in Microbiology - October 19, 2015 Category: Microbiology Authors: Altegoer F, Bange G Tags: Curr Opin Microbiol Source Type: research

Cross-regulation of Pseudomonas motility systems: the intimate relationship between flagella, pili and virulence.
Abstract Pseudomonas aeruginosa navigates using two distinct forms of motility, swimming and twitching. A polar flagellum and Type 4 pili power these movements, respectively, allowing P. aeruginosa to attach to and colonize surfaces. Single cell imaging and particle tracking algorithms have revealed a wide range of bacterial surface behaviors which are regulated by second messengers cyclic-di-GMP and cAMP; the production of these signals is, in turn, responsive to the engagement of motility organelles with a surface. Innate immune defense systems, long known to recognize structural components of flagella, appear t...
Source: Current Opinion in Microbiology - October 15, 2015 Category: Microbiology Authors: Kazmierczak BI, Schniederberend M, Jain R Tags: Curr Opin Microbiol Source Type: research

Interplay between flagellation and cell cycle control in Caulobacter.
Abstract The assembly of the flagellum, a sophisticated nanomachine powering bacterial locomotion in liquids and across surfaces, is highly regulated. In the synchronizable α-Proteobacterium Caulobacter crescentus, the flagellum is built at a pre-selected cell pole and flagellar transcript abundance oscillates during the cell cycle. Conserved regulators not only dictate when the transcripts encoding flagellar structural proteins peak, but also those encoding polarization factors. Additionally, post-transcriptional cell cycle cues facilitate flagellar (dis-)assembly at the new cell pole. Because of this regul...
Source: Current Opinion in Microbiology - October 15, 2015 Category: Microbiology Authors: Ardissone S, Viollier PH Tags: Curr Opin Microbiol Source Type: research

Towards a model for Flavobacterium gliding.
Abstract Cells of Flavobacterium johnsoniae, a rod-shaped bacterium about 6μm long, do not have flagella or pili, yet they move over surfaces at speeds of about 2μm/s. This motion is called gliding. Recent advances in F. johnsoniae research include the discovery of mobile cell-surface adhesins and rotary motors. The puzzle is how rotary motion leads to linear motion. We suggest a possible mechanism, inspired by the snowmobile. PMID: 26476806 [PubMed - as supplied by publisher] (Source: Current Opinion in Microbiology)
Source: Current Opinion in Microbiology - October 15, 2015 Category: Microbiology Authors: Shrivastava A, Berg HC Tags: Curr Opin Microbiol Source Type: research

Editorial overview: Microbial systems biology.
PMID: 26483052 [PubMed - as supplied by publisher] (Source: Current Opinion in Microbiology)
Source: Current Opinion in Microbiology - October 15, 2015 Category: Microbiology Authors: Brown ED, Typas A Tags: Curr Opin Microbiol Source Type: research

Flavobacterium gliding motility and the type IX secretion system.
Abstract Cells of Flavobacterium johnsoniae crawl rapidly over surfaces in a process called gliding motility. These cells do not have flagella or pili but instead rely on a novel motility machine composed of proteins that are unique to the phylum Bacteroidetes. The motility adhesins SprB and RemA are propelled along the cell surface by the still poorly-defined gliding motor. Interaction of these adhesins with a surface results in translocation of the cell. SprB and RemA are delivered to the cell surface by the type IX secretion system (T9SS). T9SSs are confined to but common in the phylum Bacteroidetes. Transmembr...
Source: Current Opinion in Microbiology - October 10, 2015 Category: Microbiology Authors: McBride MJ, Nakane D Tags: Curr Opin Microbiol Source Type: research

Dining in: intracellular bacterial pathogen interplay with autophagy.
Abstract Intracellular bacterial pathogens have evolved many ways to manipulate host cells for successful infection. Many of these pathogens use specialized secretion systems to inject bacterial proteins into the host cytosol that manipulate cellular processes to favor infection. Autophagy is a eukaryotic cellular remodeling process with a critical role in many diseases, including bacterial clearance. A growing field of research highlights mechanisms used by intracellular bacteria to manipulate autophagy as a pro-survival strategy. This review focuses on a select group of bacterial pathogens with diverse intracell...
Source: Current Opinion in Microbiology - October 10, 2015 Category: Microbiology Authors: Winchell CG, Steele S, Kawula T, Voth DE Tags: Curr Opin Microbiol Source Type: research

Dynamism and regulation of the stator, the energy conversion complex of the bacterial flagellar motor.
Abstract Many motile bacteria swim by rotating their motility organ, the flagellum. Rotation of the flagellum is driven by a motor at its base, and torque is generated by the rotor-stator interaction coupled with the specific ion flow through the channel in the stator. Because the stator works as an energy-conversion complex in the motor, understanding the functional mechanism of the stator is critically important. But its characterization has been hampered due to the difficulty in isolating the functional stator complex from the membrane. Recently, successful new approaches for studying the stator have been repor...
Source: Current Opinion in Microbiology - October 9, 2015 Category: Microbiology Authors: Kojima S Tags: Curr Opin Microbiol Source Type: research

Recent contributions of structure-based drug design to the development of antibacterial compounds.
Abstract According to a Pew Research study published in February 2015, there are 37 antibacterial programs currently in clinical trials in the United States. Protein structure-based methods for guiding small molecule design were used in at least 34 of these programs. Typically, this occurred at an early stage (drug discovery and/or lead optimization) prior to an Investigational New Drug (IND) application, although sometimes in retrospective studies to rationalize biological activity. Recognizing that structure-based methods are resource-intensive and often require specialized equipment and training, the NIAID has ...
Source: Current Opinion in Microbiology - October 9, 2015 Category: Microbiology Authors: Staker BL, Buchko GW, Myler PJ Tags: Curr Opin Microbiol Source Type: research

Nitrate, nitrite and nitric oxide reductases: from the last universal common ancestor to modern bacterial pathogens.
;umler AJ Abstract The electrochemical gradient that ensues from the enzymatic activity of cytochromes such as nitrate reductase, nitric oxide reductase, and quinol oxidase contributes to the bioenergetics of the bacterial cell. Reduction of nitrogen oxides by bacterial pathogens can, however, be uncoupled from proton translocation and biosynthesis of ATP or NH4(+), but still linked to quinol and NADH oxidation. Ancestral nitric oxide reductases, as well as cytochrome c oxidases and quinol bo oxidases evolved from the former, are capable of binding and detoxifying nitric oxide to nitrous oxide. The NO-metabolizing...
Source: Current Opinion in Microbiology - September 28, 2015 Category: Microbiology Authors: Vázquez-Torres A, Bäumler AJ Tags: Curr Opin Microbiol Source Type: research

Advancing gut microbiome research using cultivation.
Abstract Culture-independent approaches have driven the field of microbiome research and illuminated intricate relationships between the gut microbiota and human health. However, definitively associating phenotypes to specific strains or elucidating physiological interactions is challenging for metagenomic approaches. Recently a number of new approaches to gut microbiota cultivation have emerged through the integration of high-throughput phylogenetic mapping and new simplified cultivation methods. These methodologies are described along with their potential use within microbiome research. Deployment of novel culti...
Source: Current Opinion in Microbiology - September 21, 2015 Category: Microbiology Authors: Sommer MO Tags: Curr Opin Microbiol Source Type: research

Editorial overview: Antimicrobials.
PMID: 26384621 [PubMed - as supplied by publisher] (Source: Current Opinion in Microbiology)
Source: Current Opinion in Microbiology - September 15, 2015 Category: Microbiology Authors: Dunman PM, Tomaras AP Tags: Curr Opin Microbiol Source Type: research

Nuclear autonomy in multinucleate fungi.
Abstract Within many fungal syncytia, nuclei behave independently despite sharing a common cytoplasm. Creation of independent nuclear zones of control in one cell is paradoxical considering random protein synthesis sites, predicted rapid diffusion rates, and well-mixed cytosol. In studying the surprising fungal nuclear autonomy, new principles of cellular organization are emerging. We discuss the current understanding of nuclear autonomy, focusing on asynchronous cell cycle progression where most work has been directed. Mechanisms underlying nuclear autonomy are diverse including mRNA localization, ploidy variabil...
Source: Current Opinion in Microbiology - September 14, 2015 Category: Microbiology Authors: Roberts SE, Gladfelter AS Tags: Curr Opin Microbiol Source Type: research

Editorial overview: Eukaryotic microbes: models and beyond.
PMID: 26371422 [PubMed - as supplied by publisher] (Source: Current Opinion in Microbiology)
Source: Current Opinion in Microbiology - September 11, 2015 Category: Microbiology Authors: Martin SG Tags: Curr Opin Microbiol Source Type: research

Bacterial CRISPR: accomplishments and prospects.
Abstract In this review we briefly describe the development of CRISPR tools for genome editing and control of transcription in bacteria. We focus on the Type II CRISPR/Cas9 system, provide specific examples for use of the system, and highlight the advantages and disadvantages of CRISPR versus other techniques. We suggest potential strategies for combining CRISPR tools with high-throughput approaches to elucidate gene function in bacteria. PMID: 26363124 [PubMed - as supplied by publisher] (Source: Current Opinion in Microbiology)
Source: Current Opinion in Microbiology - September 9, 2015 Category: Microbiology Authors: Peters JM, Silvis MR, Zhao D, Hawkins JS, Gross CA, Qi LS Tags: Curr Opin Microbiol Source Type: research

Applications of imaging for bacterial systems biology.
Abstract Imaging has fueled exciting advances in bacterial cell biology, which have led to exquisite understanding of mechanisms of protein localization and cell growth in select cases. Nonetheless, it remains a challenge to connect subcellular dynamics to cellular phenotypes. In this review, I explore synergies between imaging and systems approaches to bacterial physiology. I highlight how single-cell, time-lapse imaging under environmental or chemical perturbations yields insights that complement traditional observations based on population-level growth on long time-scales. Next, I discuss applications of high-t...
Source: Current Opinion in Microbiology - September 7, 2015 Category: Microbiology Authors: Huang KC Tags: Curr Opin Microbiol Source Type: research

In the midst of the antimicrobial discovery conundrum: an overview.
PMID: 26356257 [PubMed - as supplied by publisher] (Source: Current Opinion in Microbiology)
Source: Current Opinion in Microbiology - September 6, 2015 Category: Microbiology Authors: Tomaras AP, Dunman PM Tags: Curr Opin Microbiol Source Type: research

Translational deficiencies in antibacterial discovery and new screening paradigms.
Abstract An impending disaster is currently developing in the infectious disease community: the combination of rapidly emerging multidrug-resistance among clinically relevant bacterial pathogens, together with an unprecedented withdrawal from industrial dedication to this disease area, is jeopardizing human health on a societal level. For those who remain focused and dedicated to identifying solutions to this growing problem, additional challenges await when in vitro activity does not correlate with in vivo efficacy. Thus the development of more effective translational assays will greatly improve and streamline th...
Source: Current Opinion in Microbiology - September 6, 2015 Category: Microbiology Authors: Dunman PM, Tomaras AP Tags: Curr Opin Microbiol Source Type: research

Anti-infective vaccination in the 21st century-new horizons for personal and public health.
Abstract The 21st century has seen the licensure of new anti-infective vaccines that have demonstrated their benefit for both individual and population (herd) protection. Despite this there are still many human pathogens for which no vaccine is available. As we learn more about these pathogens, and as technologies advance, more opportunities for vaccine development have become available. This review will address these advances and highlight the paradigm shift from vaccines that are used on a population basis, to others which will have an individual benefit, if successfully licensed, but are not expected to have wi...
Source: Current Opinion in Microbiology - September 4, 2015 Category: Microbiology Authors: Scully IL, Swanson K, Green L, Jansen KU, Anderson AS Tags: Curr Opin Microbiol Source Type: research

Regulation of contractile ring formation and septation in Schizosaccharomyces pombe.
Abstract The fission yeast Schizosaccharomyces pombe has become a powerful model organism for cytokinesis studies, propelled by pioneering genetic screens in the 1980s and 1990s. S. pombe cells are rod-shaped and divide similarly to mammalian cells, utilizing a medially-placed actin-and myosin-based contractile ring. A cell wall division septum is deposited behind the constricting ring, forming the new ends of each daughter cell. Here we discuss recent advances in our understanding of the regulation of contractile ring formation through formin proteins and the role of the division septum in S. pombe cell division....
Source: Current Opinion in Microbiology - September 1, 2015 Category: Microbiology Authors: Willet AH, McDonald NA, Gould KL Tags: Curr Opin Microbiol Source Type: research

Cell fusion in Neurospora crassa.
er A Abstract In recent years, the filamentous fungus Neurospora crassa has advanced as a model organism for studying eukaryotic cell-cell communication and fusion. Cell merger in this fungus employs an unusual mode of communication, in which the fusion partners appear to switch between signal sending and receiving. Many molecular factors mediating this intriguing mechanism and the subsequent membrane merger have been identified. It has become apparent that conserved factors, such as MAP kinases, NADPH oxidases and the STRIPAK complex, together with fungal specific proteins are wired into an intricate signaling ne...
Source: Current Opinion in Microbiology - September 1, 2015 Category: Microbiology Authors: Herzog S, Schumann MR, Fleißner A Tags: Curr Opin Microbiol Source Type: research

High-throughput bacterial functional genomics in the sequencing era.
Abstract High-throughput functional genomic technologies are accelerating progress in understanding the diversity of bacterial life and in developing a systems-level understanding of model bacterial organisms. Here we highlight progress in deep-sequencing-based functional genomics, show how whole genome sequencing is enabling phenotyping in organisms recalcitrant to genetic approaches, recount the rapid proliferation of functional genomic approaches to non-growth phenotypes, and discuss how advances are enabling genome-scale resource libraries for many different bacteria. PMID: 26336012 [PubMed - as supplied ...
Source: Current Opinion in Microbiology - August 31, 2015 Category: Microbiology Authors: Gray AN, Koo BM, Shiver AL, Peters JM, Osadnik H, Gross CA Tags: Curr Opin Microbiol Source Type: research

Shift and adapt: the costs and benefits of karyotype variations.
Abstract Variation is the spice of life or, in the case of evolution, variation is the necessary material on which selection can act to enable adaptation. Karyotypic variation in ploidy (the number of homologous chromosome sets) and aneuploidy (imbalance in the number of chromosomes) are fundamentally different than other types of genomic variants. Karyotypic variation emerges through different molecular mechanisms than other mutational events, and unlike mutations that alter the genome at the base pair level, rapid reversion to the wild type chromosome number is often possible. Although karyotypic variation has l...
Source: Current Opinion in Microbiology - August 25, 2015 Category: Microbiology Authors: Gerstein AC, Berman J Tags: Curr Opin Microbiol Source Type: research

Antibacterial monoclonal antibodies: the next generation?
Abstract There is a clear need for renewed efforts to combat the increasing incidence of antibiotic resistance. While the antibiotic resistance epidemic is due in part to the misuse of antibiotics, even proper empiric antibiotic therapy increases the selective pressure and potential for drug-resistance and spread of resistance mechanisms between bacteria. Antibiotic resistance coupled with the detrimental effects of broad-spectrum antibiotics on the healthy microbiome, have led the field to explore pathogen specific antibacterials such as monoclonal antibodies (mAbs). Medical need along with advances in mAb discov...
Source: Current Opinion in Microbiology - August 21, 2015 Category: Microbiology Authors: DiGiandomenico A, Sellman BR Tags: Curr Opin Microbiol Source Type: research

New chemical tools to probe cell wall biosynthesis in bacteria.
Abstract Some of the most successful drugs in the antibiotic pharmacopeia are those that inhibit bacterial cell wall biosynthesis. However, the worldwide spread of bacterial antibiotic resistance has eroded the clinical efficacy of these drugs and the antibiotic pipeline continues to be lean as drug discovery programs struggle to bring new agents to the clinic. Nevertheless, cell wall biogenesis remains a high interest and celebrated target. Recent advances in the preparation of chemical probes and biosynthetic intermediates provide the tools necessary to better understand cell wall assembly. Likewise, these tools...
Source: Current Opinion in Microbiology - August 17, 2015 Category: Microbiology Authors: Gale RT, Brown ED Tags: Curr Opin Microbiol Source Type: research

Mechanics and morphogenesis of fission yeast cells.
inc N Abstract The integration of biochemical and biomechanical elements is at the heart of morphogenesis. While animal cells are relatively soft objects which shape and mechanics is mostly regulated by cytoskeletal networks, walled cells including those of plants, fungi and bacteria are encased in a rigid cell wall which resist high internal turgor pressure. How these particular mechanical properties may influence basic cellular processes, such as growth, shape and division remains poorly understood. Recent work using the model fungal cell fission yeast, Schizosaccharomyces pombe, highlights important contributio...
Source: Current Opinion in Microbiology - August 17, 2015 Category: Microbiology Authors: Davì V, Minc N Tags: Curr Opin Microbiol Source Type: research

Taking a bite: Amoebic trogocytosis in Entamoeba histolytica and beyond.
Abstract Entamoeba histolytica is a diarrheal pathogen with the ability to cause profound host tissue damage. This organism possesses contact-dependent cell killing activity, which is likely to be a major contributor to tissue damage. E. histolytica trophozoites were recently shown to ingest fragments of living human cells. It was demonstrated that this process, termed amoebic trogocytosis, contributes to cell killing. Recent advances in ex vivo and 3-D cell culture approaches have shed light on mechanisms for tissue destruction by E. histolytica, allowing amoebic trogocytosis to be placed in the context of additi...
Source: Current Opinion in Microbiology - August 12, 2015 Category: Microbiology Authors: Ralston KS Tags: Curr Opin Microbiol Source Type: research

Comparative mapping of host-pathogen protein-protein interactions.
Abstract Pathogens usurp a variety of host pathways via protein-protein interactions to ensure efficient pathogen replication. Despite the existence of an impressive toolkit of systematic and unbiased approaches, we still lack a comprehensive list of these PPIs and an understanding of their functional implications. Here, we highlight the importance of harnessing genetic diversity of hosts and pathogens for uncovering the biochemical basis of pathogen restriction, virulence, fitness, and pathogenesis. We further suggest that integrating physical interaction data with orthogonal types of data will allow researchers ...
Source: Current Opinion in Microbiology - August 10, 2015 Category: Microbiology Authors: Shah PS, Wojcechowskyj JA, Eckhardt M, Krogan NJ Tags: Curr Opin Microbiol Source Type: research

Transferrin-mediated iron sequestration as a novel therapy for bacterial and fungal infections.
Abstract Pathogenic microbes must acquire essential nutrients, including iron, from the host in order to proliferate and cause infections. Iron sequestration is an ancient host antimicrobial strategy. Thus, enhancing iron sequestration is a promising, novel anti-infective strategy. Unfortunately, small molecule iron chelators have proven difficult to develop as anti-infective treatments, in part due to unacceptable toxicities. Iron sequestration in mammals is predominantly mediated by the transferrin family of iron-binding proteins. In this review, we explore the possibility of administering supraphysiological lev...
Source: Current Opinion in Microbiology - August 8, 2015 Category: Microbiology Authors: Bruhn KW, Spellberg B Tags: Curr Opin Microbiol Source Type: research

Comparative biology of cell division in the fission yeast clade.
Abstract Cytokinesis must be regulated in time and space in order to preserve genome integrity during cell proliferation and to allow daughter cells to adopt distinct fates and geometries during differentiation. The fission yeast Schizosaccharomyces pombe has been a popular model organism for understanding spatiotemporal regulation of cytokinesis in a symmetrically dividing cell. Recent work on another member of the same genus, Schisozaccharomyces japonicus, suggests that S. pombe may have evolved an unusual division site placement mechanism based on a recently duplicated anillin paralog. Here we discuss an extrao...
Source: Current Opinion in Microbiology - August 8, 2015 Category: Microbiology Authors: Gu Y, Oliferenko S Tags: Curr Opin Microbiol Source Type: research