scholarly journals Characterization of Erwinia tracheiphila bacteriophage FBB1 isolated from spotted cucumber beetles that vector E. tracheiphila

2021 ◽  
Author(s):  
Benzhong Fu ◽  
Yingyan Zhai ◽  
Mark L. Gleason ◽  
Gwyn A Beattie

Erwinia tracheiphila, the causal pathogen of bacterial wilt of cucurbit crops, is disseminated by cucumber beetles. A bacteriophage, designated FBB1, was isolated from spotted cucumber beetles (Diabrotica undecimpunctata) that were collected from a field where E. tracheiphila is endemic. FBB1 was classified into the Myoviridae family based on its morphology, which includes an elongated icosahedral head (106 × 82 nm) and a putatively contractile tail (120 nm). FBB1 infected all 62 E. tracheiphila strains examined and also three Pantoea spp. strains. FBB1 virions were stable at 55°C for 1 h and tolerated a pH range from 3 to 12. FBB1 has a genome of 175,994 bp with 316 predicted coding sequences and a GC content of 36.5%. The genome contains genes for a major bacterial outer-membrane protein, a putative exopolysaccharide depolymerase, and 22 predicted tRNAs. The morphology and genome indicate that FBB1 is a T4-like virus and thus in the Tevenvirinae subfamily. FBB1 is the first virulent phage of E. tracheiphila to be reported, and to date, is one of only two bacteriophages to be isolated from insect vectors of phytopathogens. Collectively, the results support FBB1 as a promising candidate for biocontrol of E. tracheiphila based on its virulent (lytic) rather than lysogenic lifestyle, its infection of all E. tracheiphila strains examined to date, and its infection of a few non-pathogenic bacteria that could be used to support phage populations when pathogen numbers are low.

2010 ◽  
Vol 24 (4) ◽  
pp. 874-874
Author(s):  
Kiymet Bozaoglu ◽  
Joanne E. Curran ◽  
Claire J. Stocker ◽  
Mohamed S. Zaibi ◽  
David Segal ◽  
...  

Abstract Context: Chemerin is a new adipokine associated with obesity and the metabolic syndrome. Gene expression levels of chemerin were elevated in the adipose depots of obese compared with lean animals and was markedly elevated during differentiation of fibroblasts into mature adipocytes. Objective: To identify factors that affect the regulation and potential function of chemerin using a genetics approach. Design, setting, patients and intervention: Plasma chemerin levels were measured in subjects from the San Antonio Family Heart Study (SAFHS), a large family-based genetic epidemiological study including 1354 Mexican American individuals. Individuals were randomly sampled without regard to phenotype or disease status. Main Outcome Measures: A genome wide association analysis using 542,944 SNPs in a subset of 523 of the same subjects was undertaken. The effect of chemerin on angiogenesis was measured using human endothelial cells and interstitial cells in co-culture in a specially formulated medium. Results: Serum chemerin levels were found to be highly heritable (h2 = 0.25; P = 1.4 x 10−9). The SNP showing strongest evidence of association (rs347344; P = 1.4 x 10−6) was located within the gene encoding EDIL3, which has a known role in angiogenesis. Functional angiogenesis assays in human endothelial cells confirmed that chemerin significantly mediated the formation of blood vessels to a similar extent as VEGF. Conclusion: Here we demonstrate for the first time that plasma chemerin levels are significantly heritable and identified a novel role for chemerin as a stimulator of angiogenesis.


2021 ◽  
Vol 12 (1) ◽  
pp. 85-93
Author(s):  
Wallapat Phongtang ◽  
Ekachai Chukeatirote

Abstract Bacillus cereus is considered to be an important food poisoning agent causing diarrhea and vomiting. In this study, the occurrence of B. cereus bacteriophages in Thai fermented soybean products (Thua Nao) was studied using five B. cereus sensu lato indicator strains (four B. cereus strains and one B. thuringiensis strain). In a total of 26 Thua Nao samples, there were only two bacteriophages namely BaceFT01 and BaceCM02 exhibiting lytic activity against B. cereus. Morphological analysis revealed that these two bacteriophages belonged to the Myoviridae. Both phages were specific to B. cereus and not able to lyse other tested bacteria including B. licheniformis and B. subtilis. The two phages were able to survive in a pH range between 5 and 12. However, both phages were inactive either by treatment of 50°C for 2 h or exposure of UV for 2 h. It should be noted that both phages were chloroform-insensitive, however. This is the first report describing the presence of bacteriophages in Thua Nao products. The characterization of these two phages is expected to be useful in the food industry for an alternative strategy including the potential use of the phages as a biocontrol candidate against foodborne pathogenic bacteria.


2020 ◽  
Vol 367 (9) ◽  
Author(s):  
Natalya V Besarab ◽  
Artur E Akhremchuk ◽  
Maryna A Zlatohurska ◽  
Liudmyla V Romaniuk ◽  
Leonid N Valentovich ◽  
...  

ABSTRACT Fire blight, caused by plant pathogenic bacterium Erwinia amylovora, is one of the most important diseases of Rosaceae plants. Due to the lack of effective control measures, fire blight infections pose a recurrent threat on agricultural production worldwide. Recently, bacterial viruses, or bacteriophages, have been proposed as environmentally friendly natural antimicrobial agents for fire blight control. Here, we isolated a novel bacteriophage Hena1 with activity against E. amylovora. Further analysis revealed that Hena1 is a narrow-host-range lytic phage belonging to Myoviridae family. Its genome consists of a linear 148,842 bp dsDNA (48.42% GC content) encoding 240 ORFs and 23 tRNA genes. Based on virion structure and genomic composition, Hena1 was classified as a new species of bacteriophage subfamily Vequintavirinae. The comprehensive analysis of Hena1 genome may provide further insights into evolution of bacteriophages infecting plant pathogenic bacteria.


2010 ◽  
Vol 427 (2) ◽  
pp. 313-321 ◽  
Author(s):  
Xiaoping Fu ◽  
Jianjun Deng ◽  
Haixia Yang ◽  
Taro Masuda ◽  
Fumiyuki Goto ◽  
...  

Iron in phytoferritin from legume seeds is required for seedling germination and early growth. However, the mechanism by which phytoferritin regulates its iron complement to these physiological processes remains unknown. In the present study, protein degradation is found to occur in purified SSF (soya bean seed ferritin) (consisting of H-1 and H-2 subunits) during storage, consistent with previous results that such degradation also occurs during seedling germination. In contrast, no degradation is observed with animal ferritin under identical conditions, suggesting that SSF autodegradation might be due to the EP (extension peptide) on the exterior surface of the protein, a specific domain found only in phytoferritin. Indeed, EP-deleted SSF becomes stable, confirming the above hypothesis. Further support comes from a protease activity assay showing that EP-1 (corresponding to the EP of the H-1 subunit) exhibits significant serine protease-like activity, whereas the activity of EP-2 (corresponding to the EP of the H-2 subunit) is much weaker. Consistent with the observation above, rH-1 (recombinant H-1 ferritin) is prone to degradation, whereas its analogue, rH-2, becomes very stable under identical conditions. This demonstrates that SSF degradation mainly originates from the serine protease-like activity of EP-1. Associated with EP degradation is a considerable increase in the rate of iron release from SSF induced by ascorbate in the amyloplast (pH range, 5.8–6.1). Thus phytoferritin may have facilitated the evolution of the specific domain to control its iron complement in response to cell iron need in the seedling stage.


2020 ◽  
Vol 110 (5) ◽  
pp. 989-998
Author(s):  
Cláudio M. Vrisman ◽  
Loïc Deblais ◽  
Yosra A. Helmy ◽  
Reed Johnson ◽  
Gireesh Rajashekara ◽  
...  

Plant pathogenic bacteria in the genus Erwinia cause economically important diseases, including bacterial wilt of cucurbits caused by Erwinia tracheiphila. Conventional bactericides are insufficient to control this disease. Using high-throughput screening, 464 small molecules (SMs) with either cidal or static activity at 100 µM against a cucumber strain of E. tracheiphila were identified. Among them, 20 SMs (SM1 to SM20), composed of nine distinct chemical moiety structures, were cidal to multiple E. tracheiphila strains at 100 µM. These lead SMs had low toxicity to human cells and honey bees at 100 µM. No phytotoxicity was observed on melon plants at 100 µM, except when SM12 was either mixed with Silwet L-77 and foliar sprayed or when delivered through the roots. Lead SMs did not inhibit the growth of beneficial Pseudomonas and Enterobacter species but inhibited the growth of Bacillus species. Nineteen SMs were cidal to Xanthomonas cucurbitae and showed >50% growth inhibition against Pseudomonas syringae pv. lachrymans. In addition, 19 SMs were cidal or static against Erwinia amylovora in vitro. Five SMs demonstrated potential to suppress E. tracheiphila when foliar sprayed on melon plants at 2× the minimum bactericidal concentration. Thirteen SMs reduced Et load in melon plants when delivered via roots. Temperature and light did not affect the activity of SMs. In vitro cidal activity was observed after 3 to 10 h of exposure to these five SMs. Here, we report 19 SMs that provide chemical scaffolds for future development of bactericides against plant pathogenic bacterial species.


2018 ◽  
Vol 3 (3) ◽  
pp. 85
Author(s):  
Novi Permata Sari ◽  
Rafika Sari ◽  
Eka Kartika Untari

Bacteriocin is a secondary metabolite product of lactic acid bacteria (LAB) which have an antimicrobial and potentially as a natural preservative. LAB isolates used in this study were Lactobacillus brevis, Lactobacillus casei and Lactobacillus plantarum. This study aimed to determine the antibacterial activity of bacteriocin produced by each isolate of LAB including the influence of pH and heating variation against Bacillus cereus, Bacillus subtilis and Staphylococcus epidermidis. Antibacterial activity test was done by using disc diffusion method. method. Confirmation test using proteolytic enzyme aimed to analyse that the inhibition zone produced from the activity of bacteriocin. The inhibition zone produced from L. brevis, L. casei and L. plantarum against B. cereus were 15.70, 16.43 and 14.50 mm, against B. subtilis were 13.37, 14.10 and 12.53 mm and against S. epidermidis were 11.37, 14.50 and 12.45 mm. The activity of each bacteriocin decreased with the addition of trypsin and catalase, bacteriocin was active in the pH range of 2-10 and heating temperature of 40-121oC. Statistical test showed that the addition of trypsin, catalase and the variation of pH also heating had significant differences (p<0.05) to antibacterial activity produced by bacteriocin from L. brevis, L. casei and L. plantarum. 


2019 ◽  
Vol 6 (2) ◽  
Author(s):  
Bhakti Etza Setiani ◽  
Yoyok Budi Pramono ◽  
Lutfi Purwitasari

A study was conducted to review on pathogenic bacteria Listeria monocytogenes, the detection and the sequencing gene methods isolated from meat products, compare selected methods that detect the presence of Listeria monocytogenes in selected raw and processed meat products. Results indicate that Listeria monocytogenenes (originally named Bacterium monocytogenes) is a gram-positive, non-sporeforming, highly mobile, rod-type, and facultative anaerobic bacterium species. It can grow under temperatures between -1.5°C to 45°C and at pH range between 4.4 and 9.4, with the optimum pH of 7. Rapid methods (PCR based and VIDAS-LDUO®) detected Listeria monocytogenes faster than the conventional method. It was also gathered that Phenotypic identification and Genotypic identification are two types of confirmation test for Listeria monocytogenes. Listeria monocytogenenes can be found in raw meat and meat product because of environmental contamination, cross contamination or error process.


2020 ◽  
Vol 9 (37) ◽  
Author(s):  
Israel García-Cano ◽  
Walaa E. Hussein ◽  
Diana Rocha-Mendoza ◽  
Ahmed E. Yousef ◽  
Rafael Jiménez-Flores

ABSTRACT The novel strain Lactobacillus rhamnosus OSU-PECh-69 was isolated from provolone cheese. It produces antimicrobial agents having a molecular mass of 5 to 10 kDa that are active against Gram-positive and Gram-negative bacteria. The strain has a genome sequence of 3,057,669 bp, a GC content of 46.6%, and up to two gene clusters encoding bacteriocins.


2020 ◽  
Vol 6 (12) ◽  
pp. eaay6687 ◽  
Author(s):  
Haojie Sun ◽  
Su Fu ◽  
Shuang Cui ◽  
Xiangsha Yin ◽  
Xiaoyan Sun ◽  
...  

A genome editing technique based on the clustered regularly interspaced short palindromic repeats (CRISPR)–associated endonuclease Cas9 enables efficient modification of genes in various cell types, including neurons. However, neuronal ensembles even in the same brain region are not anatomically or functionally uniform but divide into distinct subpopulations. Such heterogeneity requires gene editing in specific neuronal populations. We developed a CRISPR-SaCas9 system–based technique, and its combined application with anterograde/retrograde AAV vectors and activity-dependent cell-labeling techniques achieved projection- and function-specific gene editing in the rat brain. As a proof-of-principle application, we knocked down the cbp (CREB-binding protein), a sample target gene, in specific neuronal subpopulations in the medial prefrontal cortex, and demonstrated the significance of the projection- and function-specific CRISPR-SaCas9 system in revealing neuronal and circuit basis of memory. The high efficiency and specificity of our projection- and function-specific CRISPR-SaCas9 system could be widely applied in neural circuitry studies.


2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Suhua Feng ◽  
Zhenhui Zhong ◽  
Ming Wang ◽  
Steven E. Jacobsen

Abstract Background 5′ methylation of cytosines in DNA molecules is an important epigenetic mark in eukaryotes. Bisulfite sequencing is the gold standard of DNA methylation detection, and whole-genome bisulfite sequencing (WGBS) has been widely used to detect methylation at single-nucleotide resolution on a genome-wide scale. However, sodium bisulfite is known to severely degrade DNA, which, in combination with biases introduced during PCR amplification, leads to unbalanced base representation in the final sequencing libraries. Enzymatic conversion of unmethylated cytosines to uracils can achieve the same end product for sequencing as does bisulfite treatment and does not affect the integrity of the DNA; enzymatic methylation sequencing may, thus, provide advantages over bisulfite sequencing. Results Using an enzymatic methyl-seq (EM-seq) technique to selectively deaminate unmethylated cytosines to uracils, we generated and sequenced libraries based on different amounts of Arabidopsis input DNA and different numbers of PCR cycles, and compared these data to results from traditional whole-genome bisulfite sequencing. We found that EM-seq libraries were more consistent between replicates and had higher mapping and lower duplication rates, lower background noise, higher average coverage, and higher coverage of total cytosines. Differential methylation region (DMR) analysis showed that WGBS tended to over-estimate methylation levels especially in CHG and CHH contexts, whereas EM-seq detected higher CG methylation levels in certain highly methylated areas. These phenomena can be mostly explained by a correlation of WGBS methylation estimation with GC content and methylated cytosine density. We used EM-seq to compare methylation between leaves and flowers, and found that CHG methylation level is greatly elevated in flowers, especially in pericentromeric regions. Conclusion We suggest that EM-seq is a more accurate and reliable approach than WGBS to detect methylation. Compared to WGBS, the results of EM-seq are less affected by differences in library preparation conditions or by the skewed base composition in the converted DNA. It may therefore be more desirable to use EM-seq in methylation studies.


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