journal
MENU ▼
Read by QxMD icon Read
search

Environmental Microbiology

journal
https://www.readbyqxmd.com/read/28809452/neurotoxin-synthesis-is-positively-regulated-by-the-sporulation-transcription-factor-spo0a-in-clostridium-botulinum-type-e
#1
Gerald Mascher, Anna Mertaoja, Hannu Korkeala, Miia Lindström
Clostridium botulinum produces the most potent natural toxin, the botulinum neurotoxin (BoNT), probably to create anaerobiosis and nutrients by killing the host, and forms endospores that facilitate survival in harsh conditions and transmission. Peak BoNT production coincides with initiation of sporulation in C. botulinum cultures, which suggests common regulation. Here we show that Spo0A, the master regulator of sporulation, positively regulates BoNT production. Insertional inactivation of spo0A in C. botulinum type E strain Beluga resulted in significantly reduced BoNT production and in abolished or highly reduced sporulation in relation to wild-type controls...
August 15, 2017: Environmental Microbiology
https://www.readbyqxmd.com/read/28805355/sensing-mg-2-contributes-to-the-resistance-of-pseudomonas-aeruginosa-to-complement-mediated-opsonophagocytosis
#2
Mohammad Qadi, Sofía Izquierdo-Rabassa, Margalida Mateu Borrás, Antonio Doménech-Sánchez, Carlos Juan, Joanna B Goldberg, Robert E W Hancock, Sebastián Albertí
Pseudomonas aeruginosa adaptation to survive in the host hinges on its ability to probe the environment and respond appropriately. Rapid adaptation is often mediated by two-component regulatory systems, such as the PhoP/PhoQ system that responds to Mg(2+) ion concentration. However, there is limited information about the role of PhoQ in P. aeruginosa bloodstream infections. We used a murine model of systemic infection to test the virulence of a PhoQ-deficient mutant. Mutation of PhoQ impaired the virulence and the ability to cause bacteremia of P...
August 14, 2017: Environmental Microbiology
https://www.readbyqxmd.com/read/28805344/high-potential-for-temperate-viruses-to-drive-carbon-cycling-in-chemoautotrophy-dominated-shallow-water-hydrothermal-vents
#3
Eugenio Rastelli, Cinzia Corinaldesi, Antonio Dell'Anno, Michael Tangherlini, Eleonora Martorelli, Michela Ingrassia, Francesco Latino Chiocci, Marco Lo Martire, Roberto Danovaro
Viruses are the most abundant life forms in the world's oceans and they are key drivers of biogeochemical cycles, but their impact on the microbial assemblages inhabiting hydrothermal vent ecosystems is still largely unknown. Here, we analysed the viral life strategies and virus-host interactions in the sediments of a newly discovered shallow-water hydrothermal field of the Mediterranean Sea. Our study reveals that temperate viruses, once experimentally induced to replicate, can cause large mortality of vent microbes, significantly reducing the chemoautotrophic carbon production, while enhancing the metabolism of microbial heterotrophs and the re-cycling of the organic matter...
August 14, 2017: Environmental Microbiology
https://www.readbyqxmd.com/read/28805302/torix-group-rickettsia-are-widespread-in-culicoides-biting-midges-diptera-ceratopogonidae-reach-high-frequency-and-carry-unique-genomic-features
#4
Jack Pilgrim, Mats Ander, Claire Garros, Matthew Baylis, Gregory D D Hurst, Stefanos Siozios
There is increasing interest in the heritable bacteria of invertebrate vectors of disease as they present novel targets for control initiatives. Previous studies on biting midges (Culicoides spp.), known to transmit several RNA viruses of veterinary importance, have revealed infections with the endosymbiotic bacteria, Wolbachia and Cardinium. However, rickettsial symbionts in these vectors are underexplored. Here, we present the genome of a previously uncharacterized Rickettsia endosymbiont from Culicoides newsteadi (RiCNE)...
August 14, 2017: Environmental Microbiology
https://www.readbyqxmd.com/read/28805296/basidiomycete-specific-pscamkl1-encoding-a-camk-like-protein-kinase-is-required-for-full-virulence-of-puccinia-striiformis-f-sp-tritici
#5
Min Jiao, Dan Yu, Chenglong Tan, Jia Guo, Dingyun Lan, Ershang Han, Tuo Qi, Ralf Thomas Voegele, Zhensheng Kang, Jun Guo
Calcium/calmodulin-dependent kinases (CaMKs) are Ser/Thr protein kinases (PKs) that respond to changes in cytosolic free Ca(2+) and play diverse roles in eukaryotes. In fungi, CAMKs are generally classified into four families CAMK1, CAMKL, RAD53, and CAMK-Unique. Among these, CAMKL constitutes the largest family. In some fungal plant pathogens members of the CaMKL family have been shown to be responsible for pathogenesis. However, little is known about their role(s) in rust fungi. In this study, we functionally characterized a novel PK gene, PsCaMKL1, from Puccinia striiformis f...
August 14, 2017: Environmental Microbiology
https://www.readbyqxmd.com/read/28805294/microplastics-alter-composition-of-fungal-communities-in-aquatic-ecosystems
#6
Marie Therese Kettner, Keilor Rojas-Jimenez, Sonja Oberbeckmann, Matthias Labrenz, Hans-Peter Grossart
Despite increasing concerns about microplastic (MP) pollution in aquatic ecosystems, there is insufficient knowledge on how MP affect fungal communities. In this study, we explored the diversity and community composition of fungi attached to polyethylene (PE) and polystyrene (PS) particles incubated in different aquatic systems in north-east Germany: the Baltic Sea, the River Warnow and a wastewater treatment plant. Based on next generation 18S rRNA gene sequencing, 347 different operational taxonomic units assigned to 81 fungal taxa were identified on PE and PS...
August 14, 2017: Environmental Microbiology
https://www.readbyqxmd.com/read/28799700/expression-of-hopai-interferes-with-map-kinase-signaling-in-magnaporthe-oryzae
#7
Xue Zhang, Wende Liu, Yang Li, Guotian Li, Xu Jin-Rong
The Pmk1 and Mps1 MAP kinases are essential for appressorium formation and plant infection in Magnaporthe oryzae. However, their exact roles during invasive growth are not clear because pmk1 and mps1 mutants are defective in penetration. To further characterize their functions after penetration, in this study we expressed the Pseudomonas syringae effector HopAI known to inactivate plant MAP kinases in M. oryzae. Constitutive expression of HopAI with the RP27 or TrpC promoter resulted in defects in hyphal growth, conidiation, appressorium penetration, and pathogenicity, which is similar to the phenotype of the mps1 mutant...
August 11, 2017: Environmental Microbiology
https://www.readbyqxmd.com/read/28799697/methylmalonate-semialdehyde-dehydrogenase-mediated-metabolite-homeostasis-essentially-regulate-conidiation-polarized-germination-and-pathogenesis-in-magnaporthe-oryzae
#8
Justice Norvienyeku, Zhenhui Zhong, Lili Lin, Xie Dang, Meilian Chen, Xiaolian Lin, Honghong Zhang, Wilfred Mabeche Anjago, Lianyu Lin, Waheed Abdul, Zonghua Wang
Plants generate multitude of aldehydes under abiotic and biotic stress conditions. Ample demonstrations have shown that rice-derived aldehydes enhance the resistance of rice against the rice-blast fungus Magnaporthe oryzae. However, how the fungal pathogen nullifies the inhibitory effects of host aldehydes to establish compatible interaction remains unknown. Here we identified and evaluated the in vivo transcriptional activities of M. oryzae aldehyde dehydrogenase (ALDH) genes. Transcriptional analysis of M...
August 11, 2017: Environmental Microbiology
https://www.readbyqxmd.com/read/28799693/the-small-rna-real-a-novel-regulatory-element-embedded-in-the-pseudomonas-aeruginosa-quorum-sensing-networks
#9
Sara Carloni, Raffaella Macchi, Sara Sattin, Silvia Ferrara, Giovanni Bertoni
The small RNA ReaL of the opportunistic pathogen Pseudomonas aeruginosa has been characterized. Our results indicate that ReaL contributes to P. aeruginosa virulence. In the Galleria mellonella infection model, reaL gene deletion resulted in decreased virulence, while ReaL overexpression resulted in a hyper-virulent phenotype. We also demonstrate that ReaL is embedded in the P. aeruginosa quorum sensing (QS) with the role of linking las to pqs systems. We show that ReaL is negatively regulated by the las regulator LasR and impacts positively the synthesis of the pqs quinolone signal PQS by a positive post-transcriptional effect on the pqsC gene...
August 11, 2017: Environmental Microbiology
https://www.readbyqxmd.com/read/28799690/fluid-driven-interfacial-instabilities-and-turbulence-in-bacterial-biofilms
#10
Stefania Fabbri, Jian Li, Robert P Howlin, Amir Rmaile, Bart Gottenbos, Marko De Jager, E Michelle Starke, Marcelo Aspiras, Marilyn T Ward, Nick G Cogan, Paul Stoodley
Biofilms are thin layers of bacteria embedded within a slime matrix that live on surfaces. They are ubiquitous in nature and responsible for many medical and dental infections, industrial fouling and are also evident in ancient fossils. A biofilm structure is shaped by growth, detachment and response to mechanical forces acting on them. The main contribution to biofilm versatility in response to physical forces is the matrix that provides a platform for the bacteria to grow. The interaction between biofilm structure and hydrodynamics remains a fundamental question concerning biofilm dynamics...
August 11, 2017: Environmental Microbiology
https://www.readbyqxmd.com/read/28799685/ecological-factors-influencing-small-mammal-infection-by-anaplasma-phagocytophilum-and-borrelia-burgdorferi-s-l-in-agricultural-and-forest-landscapes
#11
Grégoire Perez, Suzanne Bastian, Amélie Chastagner, Albert Agoulon, Olivier Plantard, Gwenaël Vourc'h, Alain Butet
Small mammals are key components of numerous tick-borne disease systems, as hosts for immature ticks and pathogen reservoirs. To study the factors influencing tick-borne infection in small mammals, we trapped small mammals and collected questing ticks in spring and autumn in 2012 and 2013 at 24 sites in a 10x15 km rural landscapes (Brittany, France). Tissue samples were screened by real-time PCR for Anaplasma phagocytophilum and Borrelia burgdorferi sensu lato. Of the two dominant small mammal species captured, bank voles (Myodes glareolus) had higher prevalence than wood mice (Apodemus sylvaticus) for both infections, presumably because of specific differences in immunological defenses...
August 11, 2017: Environmental Microbiology
https://www.readbyqxmd.com/read/28772023/evidence-for-h2-consumption-by-uncultured-desulfobacterales-in-coastal-sediments
#12
Stefan Dyksma, Petra Pjevac, Kin Ovanesov, Marc Mussmann
Molecular hydrogen (H2 ) is the key intermediate in the anaerobic degradation of organic matter. Its removal by H2 -oxidizing microorganisms is essential to keep anaerobic degradation energetically favorable. Sulfate-reducing microorganisms (SRM) are known as the main H2 scavengers in anoxic marine sediments. Although the community of marine SRM has been extensively studied, those consuming H2 in situ are completely unknown. We combined metagenomics, PCR-based clone libraries, single-amplified genomes (SAGs) and metatranscriptomics to identify potentially H2 -consuming SRM in anoxic coastal sediments...
August 3, 2017: Environmental Microbiology
https://www.readbyqxmd.com/read/28771968/metabolic-potential-and-in-situ-activity-of-marine-marinimicrobia-bacteria-in-an-anoxic-water-column
#13
Anthony D Bertagnolli, Cory C Padilla, Jennifer B Glass, Bo Thamdrup, Frank J Stewart
Marinimicrobia bacteria are widespread in sub-euphotic areas of the oceans and particularly abundant in oxygen minimum zones (OMZs). Information on Marinimicrobia metabolism is sparse, making the biogeochemical influence of this group challenging to predict. Here, metagenome-assembled genomes representing Marinimicrobia subgroups PN262000N21 and ARCTIC96B-7 were retrieved to near completion (97% and 94%) from OMZ metagenomes, with contamination (14.1%) observed only in ARCTIC96B-7. Genes for aerobic carbon monoxide (CO) oxidation, polysulfide metabolism, and hydrogen utilization were identified only in PN262000N21, while genes for partial denitrification occurred in both genomes...
August 3, 2017: Environmental Microbiology
https://www.readbyqxmd.com/read/28752963/systematic-genetic-dissection-of-chitin-degradation-and-uptake-in-vibrio-cholerae
#14
Chelsea A Hayes, Triana N Dalia, Ankur B Dalia
Vibrio cholerae is a natural resident of the aquatic environment, where a common nutrient is the chitinous exoskeletons of microscopic crustaceans. Chitin utilization requires chitinases, which degrade this insoluble polymer into soluble chitin oligosaccharides. These oligosaccharides also serve as an inducing cue for natural transformation in Vibrio species. There are 7 predicted endochitinase-like genes in the V. cholerae genome. Here, we systematically dissect the contribution of each gene to growth on chitin as well as induction of natural transformation...
July 28, 2017: Environmental Microbiology
https://www.readbyqxmd.com/read/28752962/seabirds-laridae-as-a-source-of-campylobacter-spp-salmonella-spp-and-antimicrobial-resistance-in-south-africa
#15
Elisabet Moré, Teresa Ayats, Peter G Ryan, Preneshni R Naicker, Karen H Keddy, Davide Gaglio, Minke Witteveen, Marta Cerdà-Cuéllar
Zoonotic thermophilic Campylobacter and nontyphoidal Salmonella enterica are a major cause of foodborne human gastroenteritis worldwide. There is little information about reservoirs of these zoonotic agents in Africa. Thus, chicks of kelp gulls (Larus dominicanus, n=129) and greater crested terns (Thalasseus bergii, n=100) were studied at five colonies on the Western Cape coast (South Africa) during summer 2013/2014. Campylobacter spp. occurrence was 14.0% (CI95% : 9.9-19.3), with C. jejuni the most frequently isolated species, whilst that of Salmonella was 27...
July 28, 2017: Environmental Microbiology
https://www.readbyqxmd.com/read/28752961/symbiont-dynamics-and-strain-diversity-in-the-defensive-mutualism-between-lagria-beetles-and-burkholderia
#16
Laura V Flórez, Martin Kaltenpoth
Defensive mutualisms are often facultative in nature, and their evolutionary dynamics can be shaped by changes in local antagonist communities or arms races with coevolving antagonists. Under these conditions, selection may favor hosts that flexibly acquire symbionts producing compounds with bioactivity against current antagonists. Here we study the prevalence, dynamics, and strain diversity of Burkholderia gladioli bacteria in Lagria beetles, a recently described protective symbiosis involving vertical transmission and antifungal defense for the host eggs...
July 28, 2017: Environmental Microbiology
https://www.readbyqxmd.com/read/28752955/fibrobacter-communities-in-the-gastrointestinal-tracts-of-diverse-hindgut-fermenting-herbivores-are-distinct-from-those-of-the-rumen
#17
Anthony P Neumann, Caroline A McCormick, Garret Suen
The genus Fibrobacter contains cellulolytic bacteria originally isolated from the rumen. Culture-independent investigations have since identified Fibrobacter populations in gastrointestinal tracts of numerous hindgut-fermenting herbivores, but their physiology is poorly characterized due to few representative axenic cultures. To test the hypothesis that novel Fibrobacter diversity exists in hindgut fermenters, we performed culture and 16S rRNA gene amplicon sequencing on samples collected from phylogenetically diverse herbivorous hosts...
July 28, 2017: Environmental Microbiology
https://www.readbyqxmd.com/read/28752954/identification-of-gntr-as-regulator-of-the-glucose-metabolism-in-pseudomonas-aeruginosa
#18
Abdelali Daddaoua, Andrés Corral-Lugo, Juan-Luis Ramos, Tino Krell
In contrast to Escherichia coli, glucose metabolism in pseudomonads occurs exclusively through the Entner-Doudoroff (ED) pathway. This pathway, as well as the three routes to generate the initial ED pathway substrate, 6-phosphogluconate, are regulated by the PtxS, HexR and GtrS/GltR systems. With GntR (PA2320) we report here the identification of an additional regulator in Pseudomonas aeruginosa PAO1. GntR repressed its own expression as well as that of the GntP gluconate permease. In contrast to PtxS and GtrS/GltR, GntR did not modulate expression of the toxA gene encoding the exotoxin A virulence factor...
July 28, 2017: Environmental Microbiology
https://www.readbyqxmd.com/read/28752953/evidence-of-microbial-rhodopsins-in-antarctic-dry-valley-edaphic-systems
#19
Leandro D Guerrero, Surendra Vikram, Thulani P Makhalanyane, Don A Cowan
Microorganisms able to synthesize rhodopsins have the capacity to translocate ions through their membranes, using solar energy to generate a proton motive force. Rhodopsins are the most abundant phototrophic proteins in oceanic surface waters and are key constituents in marine bacterial ecology. However, it remains unclear how rhodopsins are used in most microorganisms. Despite their abundance in marine and fresh-water systems, the presence of functional rhodopsin systems in edaphic habitats has never been reported...
July 28, 2017: Environmental Microbiology
https://www.readbyqxmd.com/read/28752952/persistent-diarrhea-a-persistent-infection-with-enteropathogens-or-a-gut-commensal-dysbiosis
#20
Shafiqul A Sarker, Tahmeed Ahmed, Harald Brüssow
In children from developing countries 5 to 10 per cent of acute diarrhea (AD) episodes develop into persistent diarrhea (PD) defined by > 14 days of diarrhea duration. PD represents a major health burden leading to growth faltering. It is also associated with half of all diarrhea mortality. A rational intervention is thus crucial, but depends on an understanding of the pathogenesis of PD, which is still lacking. Many surveys were conducted in Latin America and in South Asia; they differ, however, with respect to enteropathogens associated with PD...
July 28, 2017: Environmental Microbiology
journal
journal
34611
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"