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https://www.readbyqxmd.com/read/29150962/genotype-and-diet-affect-resistance-survival-and-fecundity-but-not-fecundity-tolerance
#1
Megan A M Kutzer, Joachim Kurtz, Sophie A O Armitage
Insects are exposed to a variety of potential pathogens in their environment, many of which can severely impact fitness and health. Consequently, hosts have evolved resistance and tolerance strategies to suppress or cope with infections. Hosts utilising resistance improve fitness by clearing or reducing pathogen loads and hosts utilising tolerance reduce harmful fitness effects per pathogen load. To understand variation in, and selective pressures on resistance and tolerance we asked to what degree they are shaped by host genetic background, whether plasticity in these responses depends upon dietary environment, and whether there are interactions between these two factors...
November 18, 2017: Journal of Evolutionary Biology
https://www.readbyqxmd.com/read/29150519/biological-containment-of-genetically-modified-bacillus-subtilis
#2
Siamand Hosseini, Alex Curilovs, Simon M Cutting
Genetic manipulation of bacterial spores of the genus Bacillus has shown potential for vaccination and for delivery of drugs or enzymes. Remarkably, proteins displayed on the spore surface retain activity and generally are not degraded. The heat stability of spores coupled with their desiccation resistance makes them suitable for delivery to humans or to animals by the oral route. Despite these attributes one regulatory obstacle has remained regarding the fate of recombinant spores shed into the environment as viable spores...
November 17, 2017: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/29150516/drna-seq-implicates-sulfide-as-master-regulator-of-s-0-metabolism-in-chlorobaculum-tepidum-and-other-green-sulfur-bacteria
#3
Jacob M Hilzinger, Vidhyavathi Raman, Kevin E Shuman, Brian J Eddie, Thomas E Hanson
The green sulfur bacteria (Chlorobiaceae) are anaerobes that use electrons from reduced sulfur compounds (sulfide, S(0), and thiosulfate) as electron donors for photoautotrophic growth. Chlorobaculum tepidum, the model system for the Chlorobiaceae, both produces and consumes extracellular S(0) globules depending on the availability of sulfide in the environment. These physiological changes imply significant changes in gene regulation, which has been observed when sulfide is added to Cba. tepidum growing on thiosulfate...
November 17, 2017: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/29150515/loop-of-streptomyces-feruloyl-esterase-plays-an-important-role-in-its-activity-of-releasing-ferulic-acid-from-biomass
#4
Misugi Uraji, Haruka Tamura, Eiichi Mizohata, Jiro Arima, Kun Wan, Ken'ichi Ogawa, Tsuyoshi Inoue, Tadashi Hatanaka
Feruloyl esterases (FAEs) are key enzymes required for the production of ferulic acid from agricultural biomass. Previously, we identified and characterized R18, an FAE from Streptomyces cinnamoneus NBRC 12852, which showed no sequence similarity with the known FAEs. To determine the region involved in its catalytic activity, we constructed chimeric enzymes using R18 and its homolog (TH2-18) from S. cinnamoneus strain TH-2. Although R18 and TH2-18 showed 74% identity in their primary sequence, the recombinant proteins of these two FAEs (rR18 and rTH2-18) showed very different specific activities toward ethyl ferulate...
November 17, 2017: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/29150503/carbon-amendments-alter-microbial-community-structure-and-net-mercury-methylation-potential-in-sediments
#5
Geoff A Christensen, Anil C Somenahally, James G Moberly, Carrie M Miller, Andrew J King, Cynthia C Gilmour, Steven D Brown, Mircea Podar, Craig C Brandt, Scott C Brooks, Anthony V Palumbo, Judy D Wall, Dwayne A Elias
Neurotoxic methylmercury (MeHg) is produced by anaerobic Bacteria and Archaea possessing the genes hgcAB, but it is unknown how organic substrate and electron acceptor availability impact the distribution and abundance of these organisms. We evaluated the impact of organic substrate amendments on mercury (Hg) methylation rates, microbial community structure, and the distribution of hgcAB(+) microbes with sediments. Sediment slurries were amended with short-chain fatty acids, alcohols, or a polysaccharide. Minimal increases in MeHg were observed following lactate, ethanol and methanol amendments while a significant decrease (∼70%) was observed with cellobiose incubations...
November 17, 2017: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/29150500/dynamics-of-heterotrophic-bacterial-assemblages-within-synechococcus-cultures
#6
Qiang Zheng, Yu Wang, Rui Xie, Andrew S Lang, Yanting Liu, Jiayao Lu, Xiaodong Zhang, Jun Sun, Curtis A Suttle, Nianzhi Jiao
Interactions between photoautotrophic and heterotrophic microorganisms are central to the marine microbial ecosystem. Lab cultures of one of the dominant marine photoautotrophs, Synechococcus, have historically been difficult to render axenic, presumably because these bacteria depend upon other organisms to grow in these conditions. These tight associations between Synechococcus and heterotrophic bacteria represent a good, relevant system to study interspecies interactions. Ten individual Synechococcus strains, isolated from eutrophic and oligotrophic waters, were chosen for investigation...
November 17, 2017: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/29150498/identification-of-a-chez-like-gene-in-azorhizobium-caulinodans-a-key-gene-in-the-control-of-chemotaxis-and-colonization-of-the-host-plant
#7
Xiaolin Liu, Wei Liu, Yu Sun, Chunlei Xia, Claudine Elmerich, Zhihong Xie
Chemotaxis can provide bacteria with competitive advantages for survival in complex environments. The CheZ chemotaxis protein is a phosphatase, affecting the flagellar motor in Escherichia coli, by dephosphorylating the response regulator CheY-P protein responsible for clockwise rotation. A cheZ gene has been found in Azorhizobium caulinodans ORS571, in contrast to other rhizobial species studied so far. The CheZ protein in ORS571 has a conserved motif similar to that corresponding to the phosphatase active site in E...
November 17, 2017: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/29150446/biogenesis-of-the-bacterial-cbb3-cytochrome-c-oxidase-active-subcomplexes-support-a-sequential-assembly-model
#8
Anne Durand, Marie-Line Bourbon, Anne-Soisig Steunou, Bahia Khalfaoui-Hassani, Camille Legrand, Audrey Guitton, Chantal Astier, Soufian Ouchane
The cbb3 oxidase has a high affinity for oxygen and is required for growth of bacteria, including pathogens, in oxygen-limited environments. However, the assembly of this oxidase is poorly understood. Most cbb3 are composed of four subunits: the catalytic CcoN subunit, the two cytochromes c subunits (CcoO and CcoP) involved in electron transfer and the small CcoQ subunit with an unclear function. Here, we address the role of these four subunits in cbb3 biogenesis in the purple bacterium Rubrivivax gelatinosus Analyses of membrane proteins from different mutants revealed the presence of active CcoNQO and CcoNO subcomplexes and also showed that the CcoP subunit is not essential for their assembly...
November 17, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/29150190/metabolic-adaptation-of-intracellular-bacteria-and-fungi-to-macrophages
#9
REVIEW
Marcel Sprenger, Lydia Kasper, Michael Hensel, Bernhard Hube
The mature phagosome of macrophages is a hostile environment for the vast majority of phagocytosed microbes. In addition to active destruction of the engulfed microbes by antimicrobial compounds, restriction of essential nutrients in the phagosomal compartment contributes to microbial growth inhibition and killing. However, some pathogenic microorganisms have not only developed various strategies to efficiently withstand or counteract antimicrobial activities, but also to acquire nutrients within macrophages for intracellular replication...
November 7, 2017: International Journal of Medical Microbiology: IJMM
https://www.readbyqxmd.com/read/29149672/the-application-of-bacteriophages-as-novel-indicators-of-viral-pathogens-in-wastewater-treatment-systems
#10
Edgard Dias, James Ebdon, Huw Taylor
Many wastewater treatment technologies have been shown to remove bacterial pathogens more effectively than viral pathogens and, in aquatic environments, levels of traditional faecal indicator bacteria (FIB) do not appear to correlate consistently with levels of human viral pathogens. There is, therefore, a need for novel viral indicators of faecal pollution and surrogates of viral pathogens, especially given the increasing importance of indirect and direct wastewater reuse. Potential candidates include bacteriophages (phages) and the study described here sought to elucidate the relationship between three groups of phages (somatic coliphages (SOMPH), F-RNA coliphages (F-RNAPH) and human-specific phages infecting B...
November 9, 2017: Water Research
https://www.readbyqxmd.com/read/29149094/genomic-analysis-of-third-generation-cephalosporin-resistant-escherichia-coli-from-dairy-cow-manure
#11
Muhammad Attiq Rehman, Xianhua Yin, Dion Lepp, Chad Laing, Kim Ziebell, Guylaine Talbot, Edward Topp, Moussa Sory Diarra
The production of extended-spectrum β-lactamases (ESBLs) conferring resistance to new derivatives of β-lactams is a major public health threat if present in pathogenic Gram-negative bacteria. The objective of this study was to characterize ceftiofur (TIO)- or cefotaxime (FOX)-resistant Escherichia coli isolated from dairy cow manure. Twenty-four manure samples were collected from four farms and incubated under anaerobic conditions for 20 weeks at 4 °C or at 25 °C. A total of 37 TIO- or FOX-resistant E. coli were isolated from two of the four farms to determine their susceptibility to 14 antibiotics...
November 17, 2017: Veterinary Sciences
https://www.readbyqxmd.com/read/29149017/the-ms6-mycolyl-arabinogalactan-esterase-lysb-is-essential-for-an-efficient-mycobacteriophage-induced-lysis
#12
Adriano M Gigante, Cheri M Hampton, Rebecca S Dillard, Filipa Gil, Maria João Catalão, José Moniz-Pereira, Elizabeth R Wright, Madalena Pimentel
All dsDNA phages encode two proteins involved in host lysis, an endolysin and a holin that target the peptidoglycan and cytoplasmic membrane, respectively. Bacteriophages that infect Gram-negative bacteria encode additional proteins, the spanins, involved in disruption of the outer membrane. Recently, a gene located in the lytic cassette was identified in the genomes of mycobacteriophages, which encodes a protein (LysB) with mycolyl-arabinogalactan esterase activity. Taking in consideration the complex mycobacterial cell envelope that mycobacteriophages encounter during their life cycle, it is valuable to evaluate the role of these proteins in lysis...
November 17, 2017: Viruses
https://www.readbyqxmd.com/read/29147807/distinct-diversity-patterns-of-planctomycetes-associated-with-the-freshwater-macrophyte-nuphar-lutea-l-smith
#13
Anastasia A Ivanova, Dmitriy A Philippov, Irina S Kulichevskaya, Svetlana N Dedysh
Members of the phylum Planctomycetes were originally described as freshwater bacteria. Most recent studies, however, address planctomycete diversity in other environments colonized by these microorganisms, including marine and terrestrial ecosystems. This study was initiated in order to revisit the specific patterns of planctomycete diversity in freshwater habitats using cultivation-independent approaches. The specific focus was made on planctomycetes associated with Nuphar lutea (L.) Smith, an emergent macrophyte with floating leaves, which is widespread in the Holarctic...
November 17, 2017: Antonie Van Leeuwenhoek
https://www.readbyqxmd.com/read/29147114/antibiotic-resistant-bacterial-isolates-from-captive-green-turtles-and-in-vitro-sensitivity-to-bacteriophages
#14
Alessandro Delli Paoli Carini, Ellen Ariel, Jacqueline Picard, Lisa Elliott
This study aimed to test multidrug resistant isolates from hospitalised green turtles (Chelonia mydas) and their environment in North Queensland, Australia, for in vitro susceptibility to bacteriophages. Seventy-one Gram-negative bacteria were isolated from green turtle eye swabs and water samples. Broth microdilution tests were used to determine antibiotic susceptibility. All isolates were resistant to at least two antibiotics, with 24% being resistant to seven of the eight antibiotics. Highest resistance rates were detected to enrofloxacin (77%) and ampicillin (69...
2017: International Journal of Microbiology
https://www.readbyqxmd.com/read/29145798/experimental-transmission-of-bovine-digital-dermatitis-to-sheep-development-of-an-infection-model
#15
Jennifer H Wilson-Welder, Jarlath E Nally, David P Alt, Mitchell V Palmer, John Coatney, Paul Plummer
Digital dermatitis is an infectious cause of lameness primarily affecting cattle but also described in sheep, goats, and wild elk. Digital dermatitis is a polymicrobial infection, involving several Treponema species and other anaerobic bacteria. Although the exact etiology has not been demonstrated, a number of bacterial, host, and environmental factors are thought to contribute to disease development. To study host-bacterial interactions, a reproducible laboratory model of infection is required. The objective of this study was to demonstrate key aspects of bovine digital dermatitis lesions in an easy-to-handle sheep model...
January 1, 2017: Veterinary Pathology
https://www.readbyqxmd.com/read/29145163/spread-of-multidrug-resistant-escherichia-coli-harboring-integron-via-swine-farm-waste-water-treatment-plant
#16
Jin-Hyeong Park, Young-Ji Kim, Binn-Kim, Kun-Ho Seo
Wastewater treatment plants (WWTPs) that release treated wastewater into the environment have emerged as a major threat to public health. In this study, we investigated Escherichia coli load and antibiotic-resistance profiles across different treatment processes at a swine farm WWTP. The frequency of the detection of class 1 and 2 integrons, and their association with antibiotic resistance, were also analyzed. Samples were obtained at each of five sampling sites that represented each processing step within the WWTP...
November 13, 2017: Ecotoxicology and Environmental Safety
https://www.readbyqxmd.com/read/29145079/microbial-transcript-and-metabolome-analysis-uncover-discrepant-metabolic-pathways-in-autotrophic-and-mixotrophic-anammox-consortia
#17
Ying Feng, Yunpeng Zhao, Yongzhao Guo, Sitong Liu
The ability of anammox bacteria to utilize organic matter has drawn extensive attention. However, the metabolic discrepancies between autotrophic and mixotrophic anammox consortia need to be further explored. Here, microbial transcript and metabolomic analysis were conducted for the samples harvested in the reactors and batch assays to investigate the phenotype discrepancies and intrinsic causes in autotrophic and mixotrophic anammox consortia. Results showed that metabolically active community structures did not show significant difference between autotrophic and mixotrophic anammox consortia (C/N = 0...
October 31, 2017: Water Research
https://www.readbyqxmd.com/read/29145002/different-transport-behaviors-of-bacillus-subtilis-cells-and-spores-in-saturated-porous-media-implications-for-contamination-risks-associated-with-bacterial-sporulation-in-aquifer
#18
Qi Li, Jiakuan Yang, Wei Fan, Dandan Zhou, Xiaoyu Wang, Leilei Zhang, Mingxin Huo, John C Crittenden
In this study, we compared the transport characteristics of Bacillus subtilis cells and their spores in saturated porous media. Both the bacteria cells and spores were readily transported under lower ionic strengths (IS) (1mM), featuring high mass recovery rates (>75%). The bacteria cells recovery rate declined to 58.05% when the IS increased to 100mM; but the spores recovery rate remained at 74.54%. Spores appear to be more mobile than bacterial cells over wide range of IS. Surface properties and breakthrough curves analysis of the two bio-particles (cells and spores) indicated that attachment, straining and blocking mechanisms contribute differently to deposition processes...
November 11, 2017: Colloids and Surfaces. B, Biointerfaces
https://www.readbyqxmd.com/read/29143902/a-new-aerobic-chemolithoautotrophic-arsenic-oxidizing-microorganism-isolated-from-a-high-andean-watershed
#19
Javiera M Anguita, Claudia Rojas, Pablo A Pastén, Ignacio T Vargas
Biological arsenic oxidation has been suggested as a key biogeochemical process that controls the mobilization and fate of this metalloid in aqueous environments. To the best of our knowledge, only four aerobic chemolithoautotrophic arsenite-oxidizing (CAO) bacteria have been shown to grow via direct arsenic oxidation and to have the essential genes for chemolithoautotrophic arsenite oxidation. In this study, a new CAO bacterium was isolated from a high Andean watershed evidencing natural dissolved arsenic attenuation...
November 16, 2017: Biodegradation
https://www.readbyqxmd.com/read/29143694/cryo-scanning-electron-microscopy-sem-and-scanning-transmission-electron-microscopy-stem-in-sem-for-bio-and-organo-mineral-interface-characterization-in-the-environment
#20
Guillaume Wille, Jennifer Hellal, Patrick Ollivier, Annie Richard, Agnes Burel, Louis Jolly, Marc Crampon, Caroline Michel
Understanding biofilm interactions with surrounding substratum and pollutants/particles can benefit from the application of existing microscopy tools. Using the example of biofilm interactions with zero-valent iron nanoparticles (nZVI), this study aims to apply various approaches in biofilm preparation and labeling for fluorescent or electron microscopy and energy dispersive X-ray spectrometry (EDS) microanalysis for accurate observations. According to the targeted microscopy method, biofilms were sampled as flocs or attached biofilm, submitted to labeling using 4',6-diamidino-2-phenylindol, lectins PNA and ConA coupled to fluorescent dye or gold nanoparticles, and prepared for observation (fixation, cross-section, freezing, ultramicrotomy)...
November 16, 2017: Microscopy and Microanalysis
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