Faganvincent2263

Two bacterial strains, denoted so4 and w15, isolated from wheat straw (WS)-degrading microbial consortia, were found to grow synergistically in media containing WS as the single carbon and energy source. They were identified as Citrobacter freundii so4 and Sphingobacterium multivorum w15 based on 16S rRNA gene sequencing and comparison to the respective C. freundii and S. NSC 119875 multivorum type strains. In order to identify the mechanisms driving the synergistic interactions, we analyzed the draft genomes of the two strains and further characterized their metabolic potential. The latter analyses revealed that the strains had largely complementary substrate utilization patterns, with only 22 out of 190 compounds shared. The analyses further indicated C. freundii so4 to primarily consume amino acids and simple sugars, with laminarin as a key exception. In contrast, S. multivorum w15 showed ample capacity to transform complex polysaccharides, including intermediates of starch degradation. Sequence analyses revealed C. he WS hemicellulose and C. freundii so4 the cellobiose derived from cellulose, next to emerging oligo- or monosaccharides. Finally, C. freundii so4 may secrete secondary metabolites that S. multivorum w15 can consume, and detoxify the system by reducing the levels of (toxic) by-products. Copyright © 2020 Cortes-Tolalpa, Wang, Salles and van Elsas.Plasmodium falciparum remains one of the leading causes of child mortality, and nearly half of the world's population is at risk of contracting malaria. While pathogenesis results from replication of asexual forms in human red blood cells, it is the sexually differentiated forms, gametocytes, which are responsible for the spread of the disease. For transmission to succeed, both mature male and female gametocytes must be taken up by a female Anopheles mosquito during its blood meal for subsequent differentiation into gametes and mating inside the mosquito gut. Observed circulating numbers of gametocytes in the human host are often surprisingly low. A pre-fertilization behavior, such as skin sequestration, has been hypothesized to explain the efficiency of human-to-mosquito transmission but has not been sufficiently tested due to a lack of appropriate tools. link2 In this study, we describe the optimization of a qPCR tool that enables the relative quantification of gametocytes within very small input samples. Such a tool allows for the quantification of gametocytes in different compartments of the host and the vector that could potentially unravel mechanisms that enable highly efficient malaria transmission. We demonstrate the use of our gametocyte quantification method in mosquito blood meals from both direct skin feeding on Plasmodium gametocyte carriers and standard membrane feeding assay. Relative gametocyte abundance was not different between mosquitoes fed through a membrane or directly on the skin suggesting that there is no systematic enrichment of gametocytes picked up in the skin. Copyright © 2020 Talman, Ouologuem, Love, Howick, Mulamba, Haidara, Dara, Sylla, Sacko, Coulibaly, Dao, Sangare, Djimde and Lawniczak.Aflatoxins are secondary metabolites produced by soilborne saprophytic fungus Aspergillus flavus and closely related species that infect several agricultural commodities including groundnut and maize. The consumption of contaminated commodities adversely affects the health of humans and livestock. Aflatoxin contamination also causes significant economic and financial losses to producers. Research efforts and significant progress have been made in the past three decades to understand the genetic behavior, molecular mechanisms, as well as the detailed biology of host-pathogen interactions. A range of omics approaches have facilitated better understanding of the resistance mechanisms and identified pathways involved during host-pathogen interactions. Most of such studies were however undertaken in groundnut and maize. Current efforts are geared toward harnessing knowledge on host-pathogen interactions and crop resistant factors that control aflatoxin contamination. This study provides a summary of the recent progress made in enhancing the understanding of the functional biology and molecular mechanisms associated with host-pathogen interactions during aflatoxin contamination in groundnut and maize. Copyright © 2020 Soni, Gangurde, Ortega-Beltran, Kumar, Parmar, Sudini, Lei, Ni, Huai, Fountain, Njoroge, Mahuku, Radhakrishnan, Zhuang, Guo, Liao, Singam, Pandey, Bandyopadhyay and Varshney.Vibrio parahaemolyticus is a food-borne pathogen that causes pathogenic symptoms such as diarrhea and abdominal pain. Currently no studies have shown that either pathogenic and non-pathogenic V. parahaemolyticus possess growth heterogeneity in a human environment, such as in gastric and intestinal fluids. The tlh gene is present in both pathogenic and non-pathogenic V. parahaemolyticus strains, while the tdh and trh genes are only present in pathogenic strains. This study firstly applied simulated human gastric fluids to explore growth variability of 50 strains of V. parahaemolyticus at 37°C. The bacterial growth curves were fitted by primary modified Gompertz model, and the maximum growth rate (μ max ), lag time (LT), and their CV values were calculated to compare the stress response of pathogenic and non-pathogenic V. parahaemolyticus to simulated human gastric fluids. Results showed that the simulated human gastric fluids treatment significantly increased the μmax of pathogenic strains and shortened the lag time, while decreased the μmax of non-pathogenic strains and prolonged the lag time. Meanwhile, the CV values of genotypes (tlh +/tdh +/trh -) evidently increased, showing that the pathogenic genotype (tlh +/tdh +/trh -) strains had strong activity to simulated gastric fluids. All of the results indicated that the V. parahaemolyticus strains exhibited a great stress-resistant variability and growth heterogeneity to the simulated gastric fluids, which provides a novel insight to unlock the efficient control of pathogenic V. parahaemolyticus. Copyright © 2020 Wang, Zhao, Pan and Liu.Carica papaya L. is an important fruit crop grown by small- and large-scale farmers in Kenya for local and export markets. However, its production is constrained by papaya ringspot disease (PRSD). The disease is believed to be caused by papaya ringspot virus (PRSV). Previous attempts to detect PRSV in papaya plants showing PRSD symptoms, using enzyme-linked immunosorbent assay (ELISA) and reverse transcriptase-polymerase chain reaction (RT-PCR) procedures with primers specific to PRSV, have not yielded conclusive results. Therefore, the nature of viruses responsible for PRSD was elucidated in papaya leaves collected from 22 counties through Illumina MiSeq next-generation sequencing (NGS) and validated by RT-PCR and Sanger sequencing. Viruses were detected in 38 out of the 48 leaf samples sequenced. Sequence analysis revealed the presence of four viruses a Potyvirus named Moroccan watermelon mosaic virus (MWMV) and three viruses belonging to the genus Carlavirus. The Carlaviruses include cowpea mild mottle virards the design of long-term, sustainable disease management strategies. Copyright © 2020 Mumo, Mamati, Ateka, Rimberia, Asudi, Boykin, Machuka, Njuguna, Pelle and Stomeo.Probiotic viability is generally determined by quantifying its resistance to simulated gastric juice or to simulated intestinal fluid in in vitro tests, which measure microbial survival after given periods of contact. The use of a neutralizing agent is needed to avoid a carry-over of gastric or intestinal juice into the culture media of the subsequent analysis and to avoid any antimicrobial effect extended over the defined period of contact of the test. Neutralization of gastric juice and intestinal juice are of the utmost importance to present data accurately. Failing to do so determines a carry-over of bactericidal activity to the plates used for the enumeration, which further reduces the number of surviving cells. Examples of such incorrect adaptation of the test are available in literature. The purpose of this perspective stems from the discovery that many studies do not adhere to internationally recognized standards, e.g., EN 10402005 (European Committee for Standardization [ECS], 2005), to evaluate the basic, bactericidal activity of compounds, especially for the neutralization step. Copyright © 2020 Grispoldi, Giglietti, Traina and Cenci-Goga.Campylobacter jejuni and Campylobacter coli are major food-borne pathogens that cause bacterial gastroenteritis in humans, and poultry is considered as their most important reservoir. Macrolides, such as erythromycin, are the first-line choice for treatment of campylobacteriosis. In this study, of the 143 Campylobacter isolates recovered from poultry in central China during 2015-2017, 25.2% were erythromycin resistant. A2075G substitution in 23S ribosomal RNA (rRNA) and ribosomal methylase encoded by erm(B) were found in 4.2 and 4.9% isolates, respectively, and correlated with erythromycin resistance. The polymorphisms of CmeR-Box were also analyzed in our isolates. Among them, 9.1% isolates harbored a point deletion or insertion within the CmeR-Box, and we first showed that point deletion or insertion, but not substitution, in CmeR-Box led to high expression of cmeABC, which was significantly associated with erythromycin resistance (p less then 0.05). These results suggest that point deletion or insertion in CmeR-Box, A2075G substitution in 23S rRNA, and presence of erm(B) are three main factors to erythromycin resistance in C. jejuni and C. coli. Copyright © 2020 Cheng, Zhang, Lu, Wen, Zhao, Luo, Shao and Zhang.Abies nordmanniana is an economically important tree crop widely used for Christmas tree production. After initial growth in nurseries, seedlings are transplanted to the field. Rhizosphere bacterial communities generally impact the growth and health of the host plant. However, the dynamics of these communities during A. nordmanniana growth in nurseries, and during transplanting, has not previously been addressed. link3 By a 16S rRNA gene amplicon sequencing approach, we characterized the composition and dynamics of bacterial communities in the rhizosphere during early plant growth in field and greenhouse nurseries and for plants transplanted from the greenhouse to the field. Moreover, the N-cycling potential of rhizosphere bacteria across plant age was addressed in both nurseries. Overall, a rhizosphere core microbiome of A. nordmanniana, comprising 19.9% of the taxa at genus level, was maintained across plant age, nursery production systems, and even during the transplantation of plants from the greenhouse to the ial communities showed an increase of the relative abundance of genes involved in nitrogen fixation and denitrification by plant age. Similarly, the relative abundance of reported nitrogen-fixing or denitrifying bacteria increased by plant age. However, different community structures seemed to lead to an increased potential for nitrogen fixation and denitrification in the field versus greenhouse nurseries. Copyright © 2020 Garcia-Lemos, Gobbi, Nicolaisen, Hansen, Roitsch, Veierskov and Nybroe.