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https://www.readbyqxmd.com/read/28214390/robust-peptidoglycan-growth-by-dynamic-and-variable-multi-protein-complexes
#1
REVIEW
Manuel Pazos, Katharina Peters, Waldemar Vollmer
In Gram-negative bacteria such as Escherichia coli the peptidoglycan sacculus resides in the periplasm, a compartment that experiences changes in pH value, osmolality, ion strength and other parameters depending on the cell's environment. Hence, the cell needs robust peptidoglycan growth mechanisms to grow and divide under different conditions. Here we propose a model according to which the cell achieves robust peptidoglycan growth by employing dynamic multi-protein complexes, which assemble with variable composition from freely diffusing sets of peptidoglycan synthases, hydrolases and their regulators, whereby the composition of the active complexes depends on the cell cycle state - cell elongation or division - and the periplasmic growth conditions...
February 15, 2017: Current Opinion in Microbiology
https://www.readbyqxmd.com/read/28213732/the-potential-of-lactic-acid-bacteria-to-colonize-biotic-and-abiotic-surfaces-and-the-investigation-of-their-interactions-and-mechanisms
#2
REVIEW
Mattia Pia Arena, Vittorio Capozzi, Giuseppe Spano, Daniela Fiocco
Lactic acid bacteria (LAB) are a heterogeneous group of Gram-positive bacteria that comprise several species which have evolved in close association with humans (food and lifestyle). While their use to ferment food dates back to very ancient times, in the last decades, LAB have attracted much attention for their documented beneficial properties and for potential biomedical applications. Some LAB are commensal that colonize, stably or transiently, host mucosal surfaces, inlcuding the gut, where they may contribute to host health...
February 17, 2017: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/28213548/effects-of-gelling-agent-and-extracellular-signaling-molecules-on-the-culturability-of-marine-bacteria
#3
Anita Mac Rygaard, Mariane Schmidt Thøgersen, Kristian Fog Nielsen, Lone Gram, Mikkel Bentzon-Tilia
Only 1 % of marine bacteria are currently culturable using standard laboratory procedures and this is a major obstacle for our understanding of the biology of marine microorganisms and for the discovery of novel microbial natural products. Therefore, the purpose of the present study was to investigate if improved cultivation conditions, including the use of an alternative gelling agent, and supplementation with signaling molecules, could improve the culturability of bacteria from seawater. Substituting agar with gellan gum improved viable counts 3 - 40-fold, depending on medium composition and incubation conditions, with a maximum of 6...
February 17, 2017: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/28213545/antifungal-bacteria-on-woodland-salamander-skin-exhibit-high-taxonomic-diversity-and-geographic-variability
#4
Carly R Muletz-Wolz, Graziella V DiRenzo, Stephanie A Yarwood, Evan H Campbell Grant, Robert C Fleischer, Karen R Lips
Diverse bacteria inhabit amphibian skin, some of which inhibit growth of the fungal pathogen, Batrachochytrium dendrobatidis (Bd). Yet, there has been no systematic survey of anti-Bd bacteria across localities, species and elevations. This is important given geographic and taxonomic variation in amphibian susceptibility to Bd. Our sites were within the Appalachian Mountains where previous sampling indicated low Bd prevalence. We determined the number and identity of anti-Bd bacteria on 61 Plethodon salamanders (37 P...
February 17, 2017: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/28213542/plant-community-and-nitrogen-deposition-as-drivers-of-%C3%AE-and-%C3%AE-prokaryotic-diversity-in-reconstructed-oil-sands-soils-and-natural-boreal-forest-soils
#5
Jacynthe Masse, Cindy E Prescott, Sébastien Renaut, Yves Terrat, Sue J Grayston
The Athabasca Oil Sands deposit is one of the largest single oil deposits in the world. Following surface mining, companies are required to restore soil-like profiles that can support the previous land capabilities. The objective of this study was to assess if soil prokaryotic α- and β-diversity in oil-sands soils reconstructed 20-30 years previously, and planted to one of three vegetation types (coniferous or deciduous trees and grassland) were similar to those found in natural boreal-forest soils subject to wildfire disturbance...
February 17, 2017: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/28213031/antimicrobial-resistance-and-its-association-with-tolerance-to-heavy-metals-in-agriculture-production
#6
REVIEW
Zhongyi Yu, Lynda Gunn, Patrick Wall, Séamus Fanning
Antimicrobial resistance is a recognized public health challenge that since its emergence limits the therapeutic options available to veterinarians and clinicians alike, when treatment is warranted. This development is further compounded by the paucity of new antibiotics. The agri-food industry benefits from the availability of antimicrobial compounds for food-animal production and crop protection. Nonetheless, their improper use can result in the selection for bacteria that are phenotypically resistant to these compounds...
June 2017: Food Microbiology
https://www.readbyqxmd.com/read/28211847/syntrophic-linkage-between-predatory-carpediemonas-and-specific-prokaryotic-populations
#7
Emmo Hamann, Halina E Tegetmeyer, Dietmar Riedel, Sten Littmann, Soeren Ahmerkamp, Jianwei Chen, Philipp F Hach, Marc Strous
Most anoxic environments are populated by small (<10 μm) heterotrophic eukaryotes that prey on different microbial community members. How predatory eukaryotes engage in beneficial interactions with other microbes has rarely been investigated so far. Here, we studied an example of such an interaction by cultivating the anerobic marine flagellate, Carpediemonas frisia sp. nov. (supergroup Excavata), with parts of its naturally associated microbiome. This microbiome consisted of so far uncultivated members of the Deltaproteobacteria, Bacteroidetes, Firmicutes, Verrucomicrobia and Nanoarchaeota...
February 17, 2017: ISME Journal
https://www.readbyqxmd.com/read/28211324/aqueous-chlorination-of-fenamic-acids-kinetic-study-transformation-products-identification-and-toxicity-prediction
#8
Liyun Ma, Jian Li, Li Xu
Fenamic acids, one important type of non-steroidal anti-inflammatory drugs, are ubiquitous in environmental matrices. Thus it is of high significance to know the fate of them during chlorination disinfection considering their potential toxicity to the environment and humans. In the present study, the chlorination kinetics of three fenamic acids, i.e. mefenamic acid (MEF), tolfenamic acid (TOL) and clofenamic acid (CLO), were examined at different pHs, which followed second-order reaction under studied conditions...
February 8, 2017: Chemosphere
https://www.readbyqxmd.com/read/28210928/bacterial-resistance-to-arsenic-protects-against-protist-killing
#9
Xiuli Hao, Xuanji Li, Chandan Pal, Jon Hobman, D G Joakim Larsson, Quaiser Saquib, Hend A Alwathnani, Barry P Rosen, Yong-Guan Zhu, Christopher Rensing
Protists kill their bacterial prey using toxic metals such as copper. Here we hypothesize that the metalloid arsenic has a similar role. To test this hypothesis, we examined intracellular survival of Escherichia coli (E. coli) in the amoeba Dictyostelium discoideum (D. discoideum). Deletion of the E. coli ars operon led to significantly lower intracellular survival compared to wild type E. coli. This suggests that protists use arsenic to poison bacterial cells in the phagosome, similar to their use of copper...
February 16, 2017: Biometals: An International Journal on the Role of Metal Ions in Biology, Biochemistry, and Medicine
https://www.readbyqxmd.com/read/28210249/feeding-a-high-concentration-diet-induces-unhealthy-alterations-in-the-composition-and-metabolism-of-ruminal-microbiota-and-host-response-in-a-goat-model
#10
Canfeng Hua, Jing Tian, Ping Tian, Rihua Cong, Yanwen Luo, Yali Geng, Shiyu Tao, Yingdong Ni, Ruqian Zhao
There is limited knowledge about the impact of long-term feeding a high-concentrate (HC) diet on rumen microbiota, metabolome, and host cell functions. In this study, a combination of mass spectrometry-based metabolomics techniques, 454 pyrosequencing of 16S rDNA genes, and RT-PCR was applied to evaluate the changes of ruminal microbiota composition, ruminal metabolites, and related genes expression in rumen epithelial cells of lactating goats received either a 35% concentrate diet or a 65% concentrate diet for 4 or 19 weeks, respectively...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28209611/genetic-manipulation-of-helicobacter-pylori-virulence-function-by-host-carcinogenic-phenotypes
#11
Giovanni Suarez, Judith Romero-Gallo, Johanna C Sierra, M Blanca Piazuelo, Uma Krishna, Martin Alonso Gomez, Keith T Wilson, Richard M Peek
Helicobacter pylori is the strongest risk factor for gastric adenocarcinoma, yet only a minority of infected persons ever develop this malignancy. One cancer-linked locus is the cag type 4 secretion system (cagT4SS), which translocates an oncoprotein into host cells. A structural component of the cagT4SS is CagY, which become rapidly altered during in vivo adaptation in mice and rhesus monkeys, rendering the cagT4SS nonfunctional; however, these models rarely develop gastric cancer. We previously demonstrated that the H...
February 16, 2017: Cancer Research
https://www.readbyqxmd.com/read/28208653/molecular-characterization-of-mycolactone-producing-mycobacteria-from-aquatic-environments-in-buruli-ulcer-non-endemic-areas-in-c%C3%A3-te-d-ivoire
#12
Marcellin B Tano, Christelle Dassi, Lydia Mosi, Marina Koussémon, Bassirou Bonfoh
Non-tuberculous mycobacteria (NTM), particularly mycolactone producing mycobacteria (MPM), are bacteria found in aquatic environments causing skin diseases in humans like Buruli ulcer (BU). Although the causative agent for BU, Mycobacterium ulcerans has been identified and associated with slow-moving water bodies, the real transmission route is still unknown. This study aimed to characterize MPMs from environmental aquatic samples collected in a BU non-endemic community, Adiopodoumé, in Côte d'Ivoire. Sixty samples were collected in four types of matrices (plant biofilms, water filtrate residues, plant detritus and soils) from three water bodies frequently used by the population...
February 11, 2017: International Journal of Environmental Research and Public Health
https://www.readbyqxmd.com/read/28208612/enteric-pathogens-and-their-toxin-induced-disruption-of-the-intestinal-barrier-through-alteration-of-tight-junctions-in-chickens
#13
REVIEW
Wageha A Awad, Claudia Hess, Michael Hess
Maintaining a healthy gut environment is a prerequisite for sustainable animal production. The gut plays a key role in the digestion and absorption of nutrients and constitutes an initial organ exposed to external factors influencing bird's health. The intestinal epithelial barrier serves as the first line of defense between the host and the luminal environment. It consists of a continuous monolayer of intestinal epithelial cells connected by intercellular junctional complexes which shrink the space between adjacent cells...
February 10, 2017: Toxins
https://www.readbyqxmd.com/read/28208370/emergent-pattern-formation-in-an-interstitial-biofilm
#14
Cameron Zachreson, Christian Wolff, Cynthia B Whitchurch, Milos Toth
Collective behavior of bacterial colonies plays critical roles in adaptability, survivability, biofilm expansion and infection. We employ an individual-based model of an interstitial biofilm to study emergent pattern formation based on the assumptions that rod-shaped bacteria furrow through a viscous environment and excrete extracellular polymeric substances which bias their rate of motion. Because the bacteria furrow through their environment, the substratum stiffness is a key control parameter behind the formation of distinct morphological patterns...
January 2017: Physical Review. E
https://www.readbyqxmd.com/read/28207310/microbiological-quality-and-prevalence-of-%C3%AE-lactam-antibiotic-resistance-genes-in-oysters-crassostrea-rhizophorae
#15
Maria Aparecida da RessurreiÇão Brandão, Amanda Teixeira Sampaio Lopes, Maria Tereza da Silva Neta, Rhyan Barros Farias de Oliveira, Rachel Passos Rezende, George Rêgo Albuquerque, Verônica Dias Gonçalves, Dália Dos Prazeres Rodrigues, Guisla Boehs, Bianca Mendes Maciel
The microbiological quality of oysters reflects the microbiological quality of their habitats because they are filter feeders. The objective of this study was to assess the bacterial composition of the edible oyster Crassostrea rhizophorae in urban and preserved estuaries. Particularly, we assessed the presence of pathogenic bacteria, investigated antibiotic susceptibility in bacterial isolates, and quantified β-lactam antibiotic resistance genes (blaTEM, blaSHV, and blaKPC) via quantitative PCR of oyster DNA...
February 16, 2017: Journal of Food Protection
https://www.readbyqxmd.com/read/28207180/assembly-of-the-outermost-spore-layer-pieces-of-the-puzzle-are-coming-together
#16
George C Stewart
Certain endospore-forming soil dwelling bacteria are important human, animal, or insect pathogens. These organisms produce spores containing an outer layer, the exosporium. The exosporium is the site of interactions between the spore and the soil environment and between the spore and the infected host during the initial stages of infection. The composition and assembly process of the exosporium are poorly understood. This is partly due to the extreme stability of the exosporium that has proven to be refractive to existing methods to deconstruct the intact structure into its component parts...
February 16, 2017: Molecular Microbiology
https://www.readbyqxmd.com/read/28206708/physiological-metabolic-and-biotechnological-features-of-extremely-thermophilic-microorganisms
#17
REVIEW
James A Counts, Benjamin M Zeldes, Laura L Lee, Christopher T Straub, Michael W W Adams, Robert M Kelly
The current upper thermal limit for life as we know it is approximately 120°C. Microorganisms that grow optimally at temperatures of 75°C and above are usually referred to as 'extreme thermophiles' and include both bacteria and archaea. For over a century, there has been great scientific curiosity in the basic tenets that support life in thermal biotopes on earth and potentially on other solar bodies. Extreme thermophiles can be aerobes, anaerobes, autotrophs, heterotrophs, or chemolithotrophs, and are found in diverse environments including shallow marine fissures, deep sea hydrothermal vents, terrestrial hot springs-basically, anywhere there is hot water...
February 16, 2017: Wiley Interdisciplinary Reviews. Systems Biology and Medicine
https://www.readbyqxmd.com/read/28205590/antifouling-potential-of-nature-inspired-sulfated-compounds
#18
Joana R Almeida, Marta Correia-da-Silva, Emília Sousa, Jorge Antunes, Madalena Pinto, Vitor Vasconcelos, Isabel Cunha
Natural products with a sulfated scaffold have emerged as antifouling agents with low or nontoxic effects to the environment. In this study 13 sulfated polyphenols were synthesized and tested for antifouling potential using the anti-settlement activity of mussel (Mytilus galloprovincialis) plantigrade post-larvae and bacterial growth inhibition towards four biofilm-forming bacterial strains. Results show that some of these Nature-inspired compounds were bioactive, particularly rutin persulfate (2), 3,6-bis(β-D-glucopyranosyl) xanthone persulfate (6), and gallic acid persulfate (12) against the settlement of plantigrades...
February 13, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28205388/hydrogen-or-formate-alternative-key-players-in-methanogenic-degradation
#19
REVIEW
Bernhard Schink, Dominik Montag, Anja Keller, Nicolai Müller
Hydrogen and formate are important electron carriers in methanogenic degradation in anoxic environments such as sediments, sewage sludge digestors, and biogas reactors. Especially in the terminal steps of methanogenesis, they determine the energy budgets of secondary (syntrophically) fermenting bacteria and their methanogenic partners. The literature provides considerable data on hydrogen pool sizes in such habitats, but little data exist for formate concentrations due to technical difficulties in formate determination at low concentration...
February 15, 2017: Environmental Microbiology Reports
https://www.readbyqxmd.com/read/28203231/error-prone-dnae2-balances-the-genome-mutation-rates-in-myxococcus-xanthus-dk1622
#20
Ran Peng, Jiang-He Chen, Wan-Wan Feng, Zheng Zhang, Jun Yin, Ze-Shuo Li, Yue-Zhong Li
dnaE is an alpha subunit of the tripartite protein complex of DNA polymerase III that is responsible for the replication of bacterial genome. The dnaE gene is often duplicated in many bacteria, and the duplicated dnaE gene was reported dispensable for cell survivals and error-prone in DNA replication in a mystery. In this study, we found that all sequenced myxobacterial genomes possessed two dnaE genes. The duplicate dnaE genes were both highly conserved but evolved divergently, suggesting their importance in myxobacteria...
2017: Frontiers in Microbiology
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