Methanogens Within a High Salinity Oil Reservoir From the Gulf of Mexico
In this study, we used metagenomics to examine the microbial populations within five wells of the same hydrocarbon reservoir system in the Gulf of Mexico. These elevated salinity (149–181 ppt salinity, 4–5× salinity of seawater) reservoirs have limited taxonomic and functional microbial diversity dominated by methanogens, Halanaerobium and other Firmicutes lineages, and contained less abundant lineages such as Deltaproteobacteria. Metagenome assembled genomes (MAGs) were generated and analyzed from the various wells. Methanogen MAGs were closely related to Methanohalophilus euhalobius, a known methylotrop...
Source: Frontiers in Microbiology - September 18, 2020 Category: Microbiology Source Type: research

Small Alarmone Synthetases RelP and RelQ of Staphylococcus aureus Are Involved in Biofilm Formation and Maintenance Under Cell Wall Stress Conditions
The stringent response is characterized by the synthesis of the alarmone (p)ppGpp. The phenotypic consequences resulting from (p)ppGpp accumulation vary among species, and for several pathogenic bacteria, it has been shown that the activation of the stringent response strongly affects biofilm formation and maintenance. In Staphylococcus aureus, (p)ppGpp can be synthesized by the RelA/SpoT homolog Rel upon amino acid deprivation or by the two small alarmone synthetases RelP and RelQ under cell wall stress. We found that relP and relQ increase biofilm formation under cell wall stress conditions induced by a subinhibitory van...
Source: Frontiers in Microbiology - September 18, 2020 Category: Microbiology Source Type: research

Bacteriocins Targeting Gram-Negative Phytopathogenic Bacteria: Plantibiotics of the Future
Gram-negative phytopathogenic bacteria are a significant threat to food crops. These microbial invaders are responsible for a plethora of plant diseases and can be responsible for devastating losses in crops such as tomatoes, peppers, potatoes, olives, and rice. Current disease management strategies to mitigate yield losses involve the application of chemicals which are often harmful to both human health and the environment. Bacteriocins are small proteinaceous antibiotics produced by bacteria to kill closely related bacteria and thereby establish dominance within a niche. They potentially represent a safer alternative to ...
Source: Frontiers in Microbiology - September 18, 2020 Category: Microbiology Source Type: research

Local Bacteriophage Delivery for Treatment and Prevention of Bacterial Infections
As viruses with high specificity for their bacterial hosts, bacteriophages (phages) are an attractive means to eradicate bacteria, and their potential has been recognized by a broad range of industries. Against a background of increasing rates of antibiotic resistance in pathogenic bacteria, bacteriophages have received much attention as a possible “last-resort” strategy to treat infections. The use of bacteriophages in human patients is limited by their sensitivity to acidic pH, enzymatic attack and short serum half-life. Loading phage within a biomaterial can shield the incorporated phage against many of thes...
Source: Frontiers in Microbiology - September 18, 2020 Category: Microbiology Source Type: research

Small Non-coding RNAs: Do They Encode Answers for Controlling SARS-CoV-2 in the Future?
SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) is a novel coronavirus responsible for the current COVID-19 (coronavirus disease 2019) pandemic, which has hit the world since December 2019. It has spread to about 216 countries worldwide, affecting more than 21.7 million people so far. Although clinical trials of a number of promising antiviral drugs and vaccines against COVID-19 are underway, it is hard to predict how successful these drug- or vaccine-based therapeutics are eventually going to be in combating COVID-19 because most of such therapeutic strategies have failed against human coronaviruses such as S...
Source: Frontiers in Microbiology - September 18, 2020 Category: Microbiology Source Type: research

SP_0916 Is an Arginine Decarboxylase That Catalyzes the Synthesis of Agmatine, Which Is Critical for Capsule Biosynthesis in Streptococcus pneumoniae
In this study, by biochemical characterization of the recombinant SP_0916, we determined the substrate specificity of SP_0916 and show that it is an arginine decarboxylase (speA/ADC). We also show that deletion of the polyamine transporter (potABCD) predicted to import putrescine and spermidine results in reduced CPS, while deletion of spermidine synthase (speE) for the conversion of putrescine to spermidine had no impact on the capsule. Targeted metabolomics identified a correlation between reduced levels of agmatine and loss of capsule in ΔspeA and ΔpotABCD, while agmatine levels were comparable between the e...
Source: Frontiers in Microbiology - September 18, 2020 Category: Microbiology Source Type: research

Recent Advances in Archaeal Translation Initiation
Translation initiation (TI) allows accurate selection of the initiation codon on a messenger RNA (mRNA) and defines the reading frame. In all domains of life, translation initiation generally occurs within a macromolecular complex made up of the small ribosomal subunit, the mRNA, a specialized methionylated initiator tRNA, and translation initiation factors (IFs). Once the start codon is selected at the P site of the ribosome and the large subunit is associated, the IFs are released and a ribosome competent for elongation is formed. However, even if the general principles are the same in the three domains of life, the mole...
Source: Frontiers in Microbiology - September 18, 2020 Category: Microbiology Source Type: research

Metagenomic Insights Into the Mechanisms for Biodegradation of Polycyclic Aromatic Hydrocarbons in the Oil Supply Chain
Petroleum is a very complex and diverse organic mixture. Its composition depends on reservoir location and in situ conditions and changes once crude oil is spilled into the environment, making the characteristics associated with every spill unique. Polycyclic aromatic hydrocarbons (PAHs) are common components of the crude oil and constitute a group of persistent organic pollutants. Due to their highly hydrophobic, and their low solubility tend to accumulate in soil and sediment. The process by which oil is sourced and made available for use is referred to as the oil supply chain and involves three parts: (1) upstream, (2) ...
Source: Frontiers in Microbiology - September 18, 2020 Category: Microbiology Source Type: research

Pipeline for Targeted Meta-Proteomic Analyses to Assess the Diversity of Cattle Rumen Microbial Urease
In conclusion, trypsin digestion of in-gel proteins was the optimal method for the meta-proteomic pipeline analyzing rumen microbial ureases. This pipeline provides a guide for targeted meta-proteomic analyses in other ecosystems. (Source: Frontiers in Microbiology)
Source: Frontiers in Microbiology - September 18, 2020 Category: Microbiology Source Type: research

High-Content Screening of Eukaryotic Kinase Inhibitors Identify CHK2 Inhibitor Activity Against Mycobacterium tuberculosis
A screen of a eukaryotic kinase inhibitor library in an established intracellular infection model identified a set of drug candidates enabling intracellular killing of Mycobacterium tuberculosis (M.tb). Screen validity was confirmed internally by a Z′ = 0.5 and externally by detecting previously reported host-targeting anti-M.tb compounds. Inhibitors of the CHK kinase family, specifically checkpoint kinase 2 (CHK2), showed the highest inhibition and lowest toxicity of all kinase families. The screen identified and validated DDUG, a CHK2 inhibitor, as a novel bactericidal anti-M.tb compound. CHK2 inhibition by RNAi ph...
Source: Frontiers in Microbiology - September 18, 2020 Category: Microbiology Source Type: research

Transmission of Chromosomal MDR DNA Fragment Encoding Ciprofloxacin Resistance by a Conjugative Helper Plasmid in Salmonella
Resistance to ciprofloxacin, a treatment choice for Salmonella infections, has increased dramatically in recent years in particular in serotype Salmonella Derby with most of strains carrying chromosome-encoded multiple plasmid-mediated quinolone resistance (PMQR) genes. In this work, we discovered a conjugative plasmid, pSa64-96kb, in a Salmonella Derby isolate, namely Sa64, which could extract and fuse to a multiple drug resistance (MDR) DNA fragment containing two PMQR genes, aac(6’)-Ib-cr, and qnrS2 located on the chromosome of the Salmonella strain. This process led to the formation of a new 188 kb fusion plasmid...
Source: Frontiers in Microbiology - September 18, 2020 Category: Microbiology Source Type: research

Viruses That Can and Cannot Coexist With Humans and the Future of SARS-CoV-2
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a worldwide pandemic. Many projections concerning the outbreak, such as the estimated number of cases and deaths in upcoming months, have been made available. However, what happens to the virus after the pandemic subsides has not been fully explored. In this article, we discuss the ways that past and present human viruses have emerged via zoonotic transmission, the mechanisms that they have acquired the ability for effective transmission among humans, the process to sustain a chain of transmission to coexist with humans, and the factors important for c...
Source: Frontiers in Microbiology - September 18, 2020 Category: Microbiology Source Type: research

Corrigendum: Characterization of cmcp Gene as a Pathogenicity Factor of Ceratocystis manginecans
(Source: Frontiers in Microbiology)
Source: Frontiers in Microbiology - September 18, 2020 Category: Microbiology Source Type: research

Coexistence of blaOXA-58 and tet(X) on a Novel Plasmid in Acinetobacter sp. From Pig in Shanghai, China
The purpose of this study was to characterize the complete sequence of a novel plasmid carrying tigecycline resistance gene tet(X) and carbapenemase gene blaOXA-58 from a swine Acinetobacter sp. strain SH19PTT10. Minimal inhibitory concentration (MIC) was performed using microbroth dilution method. The isolate SH19PTT10 was highly resistant (16 mg/L) to tigecycline, and also exhibited resistance to ampicillin, streptomycin, tetracycline, chloramphenicol, florfenicol, ciprofloxacin, and sulfamethoxazole/trimethoprim. Although SH19PTT10 harbored blaOXA-58, it was susceptible to cefotaxime and meropenem. The genome sequence o...
Source: Frontiers in Microbiology - September 18, 2020 Category: Microbiology Source Type: research

Diverse Bacterial Communities From Qaidam Basin of the Qinghai –Tibet Plateau: Insights Into Variations in Bacterial Diversity Across Different Regions
This study concludes that the bacterial community structure is influenced by both the spatial distance and the local environment, but environmental factors are the primary drivers of bacterial spatial patterns in the Qaidam Basin. (Source: Frontiers in Microbiology)
Source: Frontiers in Microbiology - September 18, 2020 Category: Microbiology Source Type: research

Exploiting Lactoferricin (17 –30) as a Potential Antimicrobial and Antibiofilm Candidate Against Multi-Drug-Resistant Enteroaggregative Escherichia coli
The study evaluated the in vitro antimicrobial and antibiofilm efficacy of an antimicrobial peptide (AMP), lactoferricin (17–30) [Lfcin (17–30)], against biofilm-forming multi-drug-resistant (MDR) strains of enteroaggregative Escherichia coli (EAEC), and subsequently, the in vivo antimicrobial efficacy was assessed in a Galleria mellonella larval model. Initially, minimum inhibitory concentration (MIC; 32 μM), minimum bactericidal concentration (MBC; 32 μM), and minimum biofilm eradication concentration (MBEC; 32 μM) of Lfcin (17–30) were determined against MDR-EAEC field isolates (n = 3). Lfcin ...
Source: Frontiers in Microbiology - September 18, 2020 Category: Microbiology Source Type: research

Aspergillus sydowii: Genome Analysis and Characterization of Two Heterologous Expressed, Non-redundant Xylanases
A prerequisite for the transition toward a biobased economy is the identification and development of efficient enzymes for the usage of renewable resources as raw material. Therefore, different xylanolytic enzymes are important for efficient enzymatic hydrolysis of xylan-heteropolymers. A powerful tool to overcome the limited enzymatic toolbox lies in exhausting the potential of unexplored habitats. By screening a Vietnamese fungal culture collection of 295 undiscovered fungal isolates, 12 highly active xylan degraders were identified. One of the best xylanase producing strains proved to be an Aspergillus sydowii strain fr...
Source: Frontiers in Microbiology - September 18, 2020 Category: Microbiology Source Type: research

Isotopic Fractionation Associated With Sulfate Import and Activation by Desulfovibrio vulgaris str. Hildenborough
The use of stable isotopes to trace biogeochemical sulfur cycling relies on an understanding of how isotopic fractionation is imposed by metabolic networks. We investigated the effects of the first two enzymatic steps in the dissimilatory sulfate reduction (DSR) network – sulfate permease and sulfate adenylyl transferase (Sat) – on the sulfur and oxygen isotopic composition of residual sulfate. Mutant strains of Desulfovibrio vulgaris str. Hildenborough (DvH) with perturbed expression of these enzymes were grown in batch culture, with a subset grown in continuous culture, to examine the impact of these enzymati...
Source: Frontiers in Microbiology - September 18, 2020 Category: Microbiology Source Type: research

The Composition and the Structure of MCC/Eisosomes in Neurospora crassa
MCC/eisosomes are protein-organized domains in the plasma membrane of fungi and algae. However, the composition and function(s) of MCC/eisosomes in the filamentous fungus Neurospora crassa were previously unknown. To identify proteins that localize to MCC/eisosomes in N. crassa, we isolated proteins that co-purified with the core MCC/eisosome protein LSP-1, which was tagged with GFP. Proteins that co-fractionated with LSP-1:GFP were then identified by mass spectrometry. Eighteen proteins were GFP-tagged and used to identify six proteins that highly colocalized with the MCC/eisosome marker LSP-1:RFP, while five other protei...
Source: Frontiers in Microbiology - September 18, 2020 Category: Microbiology Source Type: research

Mitigation of Salinity Stress in Wheat Seedlings Due to the Application of Phytohormone-Rich Culture Filtrate Extract of Methylotrophic Actinobacterium Nocardioides sp. NIMMe6
We report the impact of microbial inoculation of a halotolerant methylotrophic actinobacterium (Nocardioides sp. NIMMe6; LC140963) and seed coating of its phytohormone-rich bacterial culture filtrate extract (BCFE) on wheat seedlings grown under saline conditions. Different plant-growth-promoting (PGP) attributes of the bacterium in terms of its growth in N-limiting media and siderophore and phytohormone [indole-3-acetic acid (IAA) and salicylic acid] production influenced plant growth positively. Microbial inoculation and priming with BCFE resulted in improved germination (92% in primed seeds at 10 dS m–1), growth, ...
Source: Frontiers in Microbiology - September 18, 2020 Category: Microbiology Source Type: research

Fungal Community, Metabolic Diversity, and Glomalin-Related Soil Proteins (GRSP) Content in Soil Contaminated With Crude Oil After Long-Term Natural Bioremediation
Fungi have increased tolerance to environmental stress (also related to the access of pollutants, e.g., trace elements and polycyclic aromatic hydrocarbons PAHs). The aim of the study was to evaluate the mycobiome and functional diversity of fungi in long-term crude-oil contaminated soils as the potential bioremediators of oil contaminated sites. Samples were taken from three historical oil wells (over a century old) at two distances: within a 0.5 m radius of the oil wells (OWP1, OWP2, and OWP3) and within a 3 m radius from the oil wells as the controls (OW1, OW2, and OW3). Next generation sequencing (for the ITS region) w...
Source: Frontiers in Microbiology - September 17, 2020 Category: Microbiology Source Type: research

The Climate-Driven Genetic Diversity Has a Higher Impact on the Population Structure of Plasmopara viticola Than the Production System or QoI Fungicide Sensitivity in Subtropical Brazil
This study raises the hypothesis that winter weather conditions influence the overwinter survival strategy with profound effects in the population biology of P. viticola. (Source: Frontiers in Microbiology)
Source: Frontiers in Microbiology - September 17, 2020 Category: Microbiology Source Type: research

Exposure to Fungal Volatiles Can Influence Volatile Emissions From Other Ophiostomatoid Fungi
Fungal volatile organic compounds (FVOCs) can act as intra- and inter-kingdom communication signals that influence the growth and behaviors of organisms involved in antagonistic or mutualistic relationships with fungi. There is growing evidence suggesting that FVOCs can mediate interactions between organisms within and across different ecological niches. Bark beetles have established mutualistic relationships with ophiostomatoid fungi which can serve as a food source and condition host plant tissues for developing beetle larvae. While the profiles (both composition and concentrations) of volatile emission from ophiostomato...
Source: Frontiers in Microbiology - September 17, 2020 Category: Microbiology Source Type: research

In silico Phage Hunting: Bioinformatics Exercises to Identify and Explore Bacteriophage Genomes
Bioinformatics skills are increasingly relevant to research in most areas of the life sciences. The availability of genome sequences and large data sets provide unique opportunities to incorporate bioinformatics exercises into undergraduate microbiology courses. The goal of this project was to develop a teaching module to investigate the abundance and phylogenetic relationships amongst bacteriophages using a set of freely available bioinformatics tools. Computational identification and examination of bacteriophage genomes, followed by phylogenetic analyses, provides opportunities to incorporate core bioinformatics competen...
Source: Frontiers in Microbiology - September 17, 2020 Category: Microbiology Source Type: research

In vitro Study of Bedaquiline Resistance in Mycobacterium tuberculosis Multi-Drug Resistant Clinical Isolates
Tuberculosis (TB) is one of the major causes of death related to antimicrobial resistance worldwide because of the spread of Mycobacterium tuberculosis multi- and extensively drug resistant (multi-drug resistant (MDR) and extensively drug-resistant (XDR), respectively) clinical isolates. To fight MDR and XDR tuberculosis, three new antitubercular drugs, bedaquiline (BDQ), delamanid, and pretomanid were approved for use in clinical setting. Unfortunately, BDQ quickly acquired two main mechanisms of resistance, consisting in mutations in either atpE gene, encoding the target, or in Rv0678, coding for the repressor of the Mmp...
Source: Frontiers in Microbiology - September 17, 2020 Category: Microbiology Source Type: research

Function, Evolution, and Composition of the RpoS Regulon in Escherichia coli
For many bacteria, successful growth and survival depends on efficient adaptation to rapidly changing conditions. In Escherichia coli, the RpoS alternative sigma factor plays a central role in the adaptation to many suboptimal growth conditions by controlling the expression of many genes that protect the cell from stress and help the cell scavenge nutrients. Neither RpoS or the genes it controls are essential for growth and, as a result, the composition of the regulon and the nature of RpoS control in E. coli strains can be variable. RpoS controls many genetic systems, including those affecting pathogenesis, phenotypic tra...
Source: Frontiers in Microbiology - September 17, 2020 Category: Microbiology Source Type: research

Calibrating the Bacterial Growth Rate Speedometer: A Re-evaluation of the Relationship Between Basal ppGpp, Growth, and RNA Synthesis in Escherichia coli
The molecule guanosine tetraphophosphate (ppGpp) is most commonly considered an alarmone produced during acute stress. However, ppGpp is also present at low concentrations during steady-state growth. Whether ppGpp controls the same cellular targets at both low and high concentrations remains an open question and is vital for understanding growth rate regulation. It is widely assumed that basal ppGpp concentrations vary inversely with growth rate, and that the main function of basal ppGpp is to regulate transcription of ribosomal RNA in response to environmental conditions. Unfortunately, studies to confirm this relationshi...
Source: Frontiers in Microbiology - September 17, 2020 Category: Microbiology Source Type: research

Advances in Biomaterials for the Prevention and Disruption of Candida Biofilms
Candida species can readily colonize a multitude of indwelling devices, leading to biofilm formation. These three-dimensional, surface-associated Candida communities employ a multitude of sophisticated mechanisms to evade treatment, leading to persistent and recurrent infections with high mortality rates. Further complicating matters, the current arsenal of antifungal therapeutics that are effective against biofilms is extremely limited. Antifungal biomaterials are gaining interest as an effective strategy for combating Candida biofilm infections. In this review, we explore biomaterials developed to prevent Candida biofilm...
Source: Frontiers in Microbiology - September 17, 2020 Category: Microbiology Source Type: research

Probiotics, Prebiotics, Synbiotics, and Paraprobiotics as a Therapeutic Alternative for Intestinal Mucositis
Intestinal mucositis, a cytotoxic side effect of the antineoplastic drug 5-fluorouracil (5-FU), is characterized by ulceration, inflammation, diarrhea, and intense abdominal pain, making it an important issue for clinical medicine. Given the seriousness of the problem, therapeutic alternatives have been sought as a means to ameliorate, prevent, and treat this condition. Among the alternatives available to address this side effect of treatment with 5-FU, the most promising has been the use of probiotics, prebiotics, synbiotics, and paraprobiotics. This review addresses the administration of these “biotics” as a ...
Source: Frontiers in Microbiology - September 17, 2020 Category: Microbiology Source Type: research

Effects of Peptide C12-OOWW-NH2 on Transcriptome and Cell Wall of the Postharvest Fungal Pathogen Penicillium digitatum
In conclusion, these results suggested that C12O3TR could inhibit the growth of P. digitatum through various mechanisms at transcriptional level, and could influence the cell wall permeability and integrity. (Source: Frontiers in Microbiology)
Source: Frontiers in Microbiology - September 17, 2020 Category: Microbiology Source Type: research

Xylanolytic Extremozymes Retrieved From Environmental Metagenomes: Characteristics, Genetic Engineering, and Applications
Xylanolytic enzymes have extensive applications in paper, food, and feed, pharmaceutical, and biofuel industries. These industries demand xylanases that are functional under extreme conditions, such as high temperature, acidic/alkaline pH, and others, which are prevailing in bioprocessing industries. Despite the availability of several xylan-hydrolyzing enzymes from cultured microbes, there is a huge gap between what is available and what industries require. DNA manipulations as well as protein-engineering techniques are also not quite satisfactory in generating xylan-hydrolyzing extremozymes. With a compound annual growth...
Source: Frontiers in Microbiology - September 17, 2020 Category: Microbiology Source Type: research

Deciphering the Role of Trehalose in Tripartite Symbiosis Among Rhizobia, Arbuscular Mycorrhizal Fungi, and Legumes for Enhancing Abiotic Stress Tolerance in Crop Plants
Drought is a critical factor limiting the productivity of legumes worldwide. Legumes can enter into a unique tripartite symbiotic relationship with root-nodulating bacteria of genera Rhizobium, Bradyrhizobium, or Sinorhizobium and colonization by arbuscular mycorrhizal fungi (AMF). Rhizobial symbiosis provides nitrogen necessary for growth. AMF symbiosis enhances uptake of diffusion-limited nutrients such as P, Zn, Cu, etc., and also water from the soil via plant-associated fungal hyphae. Rhizobial and AMF symbioses can act synergistically in promoting plant growth and fitness, resulting in overall yield benefits under dro...
Source: Frontiers in Microbiology - September 17, 2020 Category: Microbiology Source Type: research

Complex Internal Microstructure of Feather Follicles on Chicken Skin Promotes the Bacterial Cross-Contamination of Carcasses During the Slaughtering Process
This study used hematoxylin-eosin (HE) staining of the tissue paraffin section to investigate the structure of the feather follicles on chicken skin. In addition, the biopsy sampling method was employed for the high-throughput sequencing of 16S RNA genes to study the composition and source of bacterial contamination during slaughter. The results show that the feather follicles on chicken skin form a closed cavity structure during the slaughtering process. The volume of the irregular follicle cavity was about Ø: 200 μm × D: 1040 μm, which provides a place for the bacteria to absorb and resist the cleaning...
Source: Frontiers in Microbiology - September 17, 2020 Category: Microbiology Source Type: research

Extraction and Detection of Structurally Diverse Siderophores in Soil
Although the biochemistry of bacterial and fungal siderophores has been intensively studied in laboratory cultures, their distribution and impacts on nutrient cycling and microbial communities in soils remain poorly understood. The detection of siderophores in soil is an analytical challenge because of the complexity of the soil matrix and their structural diversity. Liquid chromatography-mass spectrometry (LC-MS) is a suitable method for the sensitive analysis of siderophores in complex samples; however, siderophore extraction into liquid phases for analysis by LC-MS is problematic because of their adsorption to soil part...
Source: Frontiers in Microbiology - September 17, 2020 Category: Microbiology Source Type: research

Impact of Plant Growth Promoting Bacteria on Salicornia ramosissima Ecophysiology and Heavy Metal Phytoremediation Capacity in Estuarine Soils
Salicornia ramosissima is a C3 halophyte that grows naturally in South Western Spain salt marshes, under soil salinity and heavy metal pollution (mostly Cu, Zn, As, and Pb) caused by both natural and anthropogenic pressure. However, very few works have reported the phytoremediation potential of S. ramosissima. In this work, we studied a microbe-assisted phytoremediation strategy under greenhouse conditions. We inoculated plant growth promoting (PGP) and heavy metal resistant bacteria in pots with S. ramosissima and natural non-polluted and polluted sediments collected from Spanish estuaries. Then, we analyzed plant ecophys...
Source: Frontiers in Microbiology - September 17, 2020 Category: Microbiology Source Type: research

Flexible, Functional, and Familiar: Characteristics of SARS-CoV-2 Spike Protein Evolution
The SARS-CoV-2 S protein is a major point of interaction between the virus and the human immune system. As a consequence, the S protein is not a static target but undergoes rapid molecular evolution. In order to more fully understand the selection pressure during evolution, we examined residue positions in the S protein that vary greatly across closely related viruses but are conserved in the subset of viruses that infect humans. These “evolutionarily important” residues were not distributed evenly across the S protein but were concentrated in two domains: the N-terminal domain and the receptor-binding domain, ...
Source: Frontiers in Microbiology - September 17, 2020 Category: Microbiology Source Type: research

Glabridin Averts Biofilms Formation in Methicillin-Resistant Staphylococcus aureus by Modulation of the Surfaceome
This study clearly suggests that glabridin prevents biofilm formation in S. aureus through modulation of the cell surface proteins. (Source: Frontiers in Microbiology)
Source: Frontiers in Microbiology - September 17, 2020 Category: Microbiology Source Type: research

Artificial Larval Diet Mediates the Microbiome of Queensland Fruit Fly
In this study, high-throughput Illumina sequencing was used to assess the Qfly microbiome in colonies reared, for five generations from nature, on two common artificial diets (carrot and gel). At generation five (G5), the microbiome was assessed in larvae, pupae, adult males and adult females and standard fly quality control parameters were assessed together with additional performance measures of mating propensity and survival under nutritional stress. At the genus level, bacterial communities were significantly different between the colonies reared on the two larval diets. However, communities converged at Phyla to famil...
Source: Frontiers in Microbiology - September 16, 2020 Category: Microbiology Source Type: research

Monitoring of Nitrification in Chloraminated Drinking Water Distribution Systems With Microbiome Bioindicators Using Supervised Machine Learning
In this study, we explored the water microbiome from a chloraminated DWDS simulator operated through successive operational schemes of stable and nitrification events and utilized the 16S rRNA gene dataset to generate high-resolution taxonomic profiles for bioindicator discovery. Analysis of the microbiome revealed both an enrichment and depletion of various bacterial populations associated with nitrification. A supervised machine learning approach (naïve Bayes classifier) trained with bioindicator profiles (membership and structure) were used to classify water samples. Performance of each model was examined using the...
Source: Frontiers in Microbiology - September 16, 2020 Category: Microbiology Source Type: research

Transcriptomic Analysis of Two Lentinula edodes Genotypes With Different Cadmium Accumulation Ability
Lentinula edodes, also known as Xiang’gu, is commonly eaten in cultures around the world. However, L. edodes is particularly susceptible to enrichment with heavy metals, particularly cadmium (Cd), which is toxic to human health. Understanding the molecular mechanism and mining key genes involved in Cd enrichment will facilitate genetic modification of L. edodes strains. Two L. edodes genotypes, Le4625 (with higher Cd enrichment capability) and Le4606 (with lower Cd enrichment capability) were used in this study. The Cd concentrations in the mycelia of the tested genotypes differed significantly after Cd (0.1 mg/L) ex...
Source: Frontiers in Microbiology - September 16, 2020 Category: Microbiology Source Type: research

In vitro Activity of Lefamulin Against the Common Respiratory Pathogens Isolated From Mainland China During 2017 –2019
ConclusionIn summary, lefamulin has good and broad-spectrum coverage of respiratory pathogens (methicillin-sensitive and -resistant Staphylococcus, S. pneumoniae, β-hemolytic Streptococcus, H. influenzae, M. catarrhalis and M. pneumoniae). In vitro activity supports the use of lefamulin in the treatment of CABP in China. (Source: Frontiers in Microbiology)
Source: Frontiers in Microbiology - September 16, 2020 Category: Microbiology Source Type: research

Sodium Butyrate Reduces Salmonella Enteritidis Infection of Chicken Enterocytes and Expression of Inflammatory Host Genes in vitro
Salmonella Enteritidis (SE) is a facultative intracellular pathogen that colonizes the chicken gut leading to contamination of carcasses during processing. A reduction in intestinal colonization by SE could result in reduced carcass contamination thereby reducing the risk of illnesses in humans. Short chain fatty acids such as butyrate are microbial metabolites produced in the gut that exert various beneficial effects. However, its effect on SE colonization is not well known. The present study investigated the effect of sub-inhibitory concentrations (SICs) of sodium butyrate on the adhesion and invasion of SE in primary ch...
Source: Frontiers in Microbiology - September 16, 2020 Category: Microbiology Source Type: research

The Plant Negative-Sense RNA Virosphere: Virus Discovery Through New Eyes
The use of high-throughput sequencing (HTS) for virus diagnostics, as well as the importance of this technology as a valuable tool for discovery of novel viruses has been extensively investigated. In this review, we consider the application of HTS approaches to uncover novel plant viruses with a focus on the negative-sense, single-stranded RNA virosphere. Plant viruses with negative-sense and ambisense RNA (NSR) genomes belong to several taxonomic families, including Rhabdoviridae, Aspiviridae, Fimoviridae, Tospoviridae, and Phenuiviridae. They include both emergent pathogens that infect a wide range of plant species, and ...
Source: Frontiers in Microbiology - September 16, 2020 Category: Microbiology Source Type: research

Precise Species Identification and Taxonomy Update for the Genus Kluyvera With Reporting Kluyvera sichuanensis sp. nov.
Kluyvera is a genus within the family Enterobacteriaceae and can cause various human infections but remains poorly studied. A carbapenem-resistant blaNDM–1-carrying Kluyvera strain 090646T was isolated from a hospital sink in Chengdu, Sichuan province, China. Whole genome sequencing of the strain revealed that it had 28.2 to 42.3% in silico DNA-DNA hybridization (isDDH) scores and 84.15 to 90.10% average nucleotide identity (ANI) values with other Kluyvera species. Both values are well below the ≥ 70.0% isDDH and ≥ 95–96% ANI cutoffs to define bacterial species, suggesting that the strain represents a nov...
Source: Frontiers in Microbiology - September 16, 2020 Category: Microbiology Source Type: research

Effects of Calcium and Signal Sensing Systems on Azorhizobium caulinodans Biofilm Formation and Host Colonization
In this study, we investigated the role of calcium for biofilm formation in Azorhizobium caulindans, which forms nodules in the stem and root of its host plant Sesbania rostrata. We found that calcium is essential for A. caulindans biofilm formation, in addition to the presence of extracellular matrix components, eDNA and proteins. Also, calcium-mediated biofilm formation was tested with chemotaxis, motility, cyclic di-GMP synthesis, and quorum sensing mutants. Finally, calcium was found to promote S. rostrata root colonization of A. caulinodans. In total, these results show that calcium is essential for A. caulindans biof...
Source: Frontiers in Microbiology - September 16, 2020 Category: Microbiology Source Type: research

Agreement of Quantitative and Qualitative Antimicrobial Susceptibility Testing Methodologies: The Case of Enrofloxacin and Avian Pathogenic Escherichia coli
In conclusion, the overall agreement between the four different testing methodologies was very high. These results confirm the reliability of the disk diffusion and gradient strip test methods as substantiated alternatives, next to the gold standard agar and microbroth dilution, for fluoroquinolone susceptibility testing of APEC isolates. (Source: Frontiers in Microbiology)
Source: Frontiers in Microbiology - September 16, 2020 Category: Microbiology Source Type: research

Effects of Sulfamethoxazole on the Microbial Community Dynamics During the Anaerobic Digestion Process
Anaerobic digestion (AD) treatment of cattle manure and slurry makes it possible to produce biogas, a renewable and storable biofuel, as well as digestate, a residual organic matter that can be used to replace chemical fertilizers. On the other hand, the intense use of antibiotics (e.g., sulfamethoxazole) in animal husbandry practices is showing increasing negative impacts resulting from the release of still metabolically active molecules into agroecosystems. In the present study, cattle manure collected from an AD plant-feeding tank was used as feedstock for AD experiments in which some batches were spiked with 5 mg L&nda...
Source: Frontiers in Microbiology - September 16, 2020 Category: Microbiology Source Type: research

Fumarase From Cyanidioschyzon merolae Stably Shows High Catalytic Activity for Fumarate Hydration Under High Temperature Conditions
Fumarases (Fums) catalyze the reversible reaction converting fumarate to l-malate. There are two kinds of Fums: Class І and ІІ. Thermostable Class ІІ Fums, from mesophilic microorganisms, are utilized for industrial l-malate production. However, the low thermostability of these Fums is a limitation in industrial l-malate production. Therefore, an alternative Class ІІ Fum that shows high activity and thermostability is required to overcome this drawback. Thermophilic microalgae and cyanobacteria can use carbon dioxide as a carbon source and are easy to cultivate. Among them, Cyanidioschyzon merolae and Thermosynechoc...
Source: Frontiers in Microbiology - September 16, 2020 Category: Microbiology Source Type: research

Shared PKS Module in Biosynthesis of Synergistic Laxaphycins
Cyanobacteria produce a wide range of lipopeptides that exhibit potent membrane-disrupting activities. Laxaphycins consist of two families of structurally distinct macrocyclic lipopeptides that act in a synergistic manner to produce antifungal and antiproliferative activities. Laxaphycins are produced by range of cyanobacteria but their biosynthetic origins remain unclear. Here, we identified the biosynthetic pathways responsible for the biosynthesis of the laxaphycins produced by Scytonema hofmannii PCC 7110. We show that these laxaphycins, called scytocyclamides, are produced by this cyanobacterium and are encoded in a s...
Source: Frontiers in Microbiology - September 16, 2020 Category: Microbiology Source Type: research

Screening, Safety Evaluation, and Mechanism of Two Lactobacillus fermentum Strains in Reducing the Translocation of Staphylococcus aureus in the Caco-2 Monolayer Model
This study focuses on the screening and characterization of Lactobacillus strains with significant inhibitory effect on the translocation of S. aureus through Caco-2 monolayers. First, strains with strong affinity for mucin and Caco-2 cells were obtained, via microtiter plate assay and adhesion assay, respectively. Obtained bacteria were further tested for their inhibitory effects on the growth of S. aureus by well diffusion assay. Subsequently, two strains preincubated with Caco-2 monolayers were found to inhibit the translocation of S. aureus CMCC26003 by 80.95 and 43.96%, respectively, via the transcellular translocatio...
Source: Frontiers in Microbiology - September 16, 2020 Category: Microbiology Source Type: research