Cyclic Organic Peroxides as New Fungicides against Phytopathogenic Fungi

The search for new classes of fungicides has long been important in plant protection due to the development of fungal resistance to currently used agrochemicals. Organic peroxides have long been regarded as exotic and unstable compounds. The discovery of the antimalarial activity of the peroxide natural product Artemisinin, an achievement that was recently recognized with the Nobel Prize, has brought organic peroxides into the medicinal and agrochemistry. In this paper, fungicidal activity of synthesized organic peroxides—geminal bishydroperoxide, bridged 1,2,4,5-tetraoxanes, and tricyclic monoperoxides—were tested in vitro against an important species of phytopathogenic fungi (F. culmorum, R. solani, A. solani, P. infestans, C. coccodes). We discovered that substituted bridged 1,2,4,5-tetraoxanes exhibit fungicidal activity comparable or superior to azoxystrobin and superior to geminal bishydroperoxide and tricyclic monoperoxides. The contact mode of action was demonstrated for the bridged 1,2,4,5-tetraoxane

C6 Peptide-Based Multiplex Phosphorescence Analysis (PHOSPHAN) for Serologic Confirmation of Lyme Borreliosis

<div><p>Background</p><p>A single-tier immunoassay using the C6 peptide of VlsE (C6) from <i>Borrelia burgdorferi</i> sensu stricto (<i>Bb)</i> has been proposed as a potential alternative to conventional two-tier testing for the serologic diagnosis of Lyme disease in the United States and Europe.</p><p>Objective</p><p>To evaluate the performance of C6 peptide based multiplex Phosphorescence Analysis (PHOSPHAN) for the serologic confirmation of Lyme borreliosis (LB) in Russian patients.</p><p>Methods</p><p>Serum samples (<i>n</i> = 351) were collected from 146 patients with erythema migrans (EM); samples from 131 of these patients were taken several times prior to treatment and at different stages of recovery. The control group consisted of 197 healthy blood donors and 31 patients with other diseases, all from the same highly endemic region of Russia. All samples were analyzed by PHOSPHAN for IgM and IgG to <i>Bb</i> C6, recombinant OspC and VlsE proteins, and C6 peptides from <i>B</i>. <i>garinii</i> and <i>B</i>. <i>afzelii</i>.</p><p>Results</p><p>IgM and IgG to <i>Bb</i> C6 were identified in 43 and 95 out of 131 patients (32.8 and 72.5%, respectively); seroconversion of IgM antibodies was observed in about half of the patients (51.2%), and of IgG antibodies, in almost all of them (88.4%). Additional detection of OspC-IgM and VlsE-IgM or IgG to C6 from <i>B</i>. <i>garinii</i> or <i>B</i>. <i>afzelii</i> did not contribute significantly to the overall sensitivity of the multiplex immunoassay.</p><p>Conclusions</p><p>The multiplex phosphorescence immunoassay is a promising method for simultaneously revealing the spectrum of antibodies to several <i>Borrelia</i> antigens. Detection of IgM and IgG to <i>Bb</i> C6 in the sera of EM patients provides effective serologic confirmation of LB and, with high probability, indicates an active infection process.</p></div

Phyllobacterium zundukense sp. nov., a novel species of rhizobia isolated from root nodules of the legume species Oxytropis triphylla (Pall.) Pers.

Gram-negative strains Tri-36, Tri-38, Tri-48T and Tri-53 were isolated from root nodules of the relict legume Oxytropis triphylla (Pall.) Pers. originating from Zunduk Cape (Baikal Lake region, Russia). 16S rRNA gene sequencing showed that the novel isolates were phylogenetically closest to the type strains Phyllobacterium sophorae LMG 27899(T), Phyllobacterium brassicacearum LMG 22836(T), Phyllobacterium endophyticum LMG 26470(T) and Phyllobacterium bourgognense LMG 22837(T) while similarity levels between the isolates and the most closely related strain P. endophyticum LMG 26470(T) were 98.899.5 %. The recA and glnII genes of the isolates showed highest sequence similarities with P. sophorae LMG 27899(T) (95.4 and 89.5 %, respectively) and P. brassicacearum LMG 22836(T) (91.4 and 85.1 %, respectively). Comparative analysis of phenotypic properties between the novel isolates and the closest reference strains P. sophorae LMG 27899(T), P. brassicacearum LMG 22836(T) and P. endophyticum LMG 26470(T) was performed using a microassay system. Average nucleotide identities between the whole genome sequences of the isolates Tri-38 and Tri-48(T) and P. sophorae LMG 27899(T), P. brassicacearum LMG 22836(T) and P. endophyticum LMG 26470(T) ranged from 79.23% for P. endophyticum LMG 26470(T) to 85.74% for P. sophorae LMG 27899(T). The common nodABC genes required for legume nodulation were absent from strains Tri-38 and Tri-48(T), although some other symbiotic nod and fix genes were detected. On the basis of genotypic and phenotypic analysis, a novel species, Phyllobacterium zundukense sp. nov. (type strain Tri-48(T) = LMG 30371(T) = RCAM 03910(T)), is proposed

Sensitivity of PHOSPHAN tests for serum IgG antibody responses to <i>B</i>. <i>burgdorferi</i> C6, <i>B</i>. <i>garinii</i> C6, and <i>B</i>. <i>afzelii</i> C6 in samples from EM patients.

<p>(A) Total sensitivity of PHOSPHAN variants G₁, G₂, G₃, and G_1–3 at the baseline prior to treatment (N = 146). (B) Sensitivity of PHOSPHAN variants G₁–G₃ in tests of samples taken at the baseline (<i>n</i> = 146) and on days 8–14 (<i>n</i> = 75), 15–30 (n = 48), and 31–66 (<i>n</i> = 82) after disease onset. Values that are statistically significant (Fisher's exact test, <i>p</i> < 0.05) are denoted by brackets or asterisks. Immunoassay codes: G₁, <i>Bb</i> C6 IgG; G₂, <i>Bg</i> C6 IgG; G₃, <i>Ba</i> C6 IgG; G_1–3, any of the three antigens <i>Bb</i> C6, <i>Bg</i> C6, or <i>Ba</i> C6. (<i>Bb</i>) <i>B</i>.<i>burgdorferi</i>, (<i>Bg</i>) <i>B</i>.<i>garinii</i>, (<i>Ba</i>) <i>B</i>.<i>afzelii</i>. Legend: (B) Transparent square, G1; Black diamond, G2; Black triangle, G3.</p

Sensitivity of PHOSPHAN and C6 ELISA tests for serum IgM and IgG antibody responses to <i>B</i>. <i>burgdorferi</i> C6 in samples from EM patients.

<p>(A) Sensitivity of PHOSPHAN variants M₁, G₁, M₁G₁ and C6 ELISA (C6) at the baseline prior to treatment (N = 146). (B) Sensitivity of PHOSPHAN variants M₁ and G₁, and (C) PHOSPHAN variant M₁G₁ and C6 ELISA in tests of serum samples taken at the baseline (n = 146) and on days 8–14 (<i>n</i> = 75), 15–30 (n = 48), and 31–66 (<i>n</i> = 82) after disease onset. Values that are statistically significant (Fisher's exact test, <i>p</i> < 0.05) are denoted by brackets or asterisks. Immunoassay codes: M₁, <i>Bb</i> C6 IgM; G₁, <i>Bb</i> C6 IgG; M₁G₁, <i>Bb</i> C6 IgM+IgG; C6, Immunetics C6 Lyme ELISA kit. (<i>Bb</i>) <i>B</i>.<i>burgdorferi</i>. Legend: (B) Transparent square, M1; Black diamond, G1. (C) Black square, M1G1; Transparent circle, C6.</p