Description of Meloidoderita salina sp. n. (Nematoda, Sphaeronematidae) from a micro-tidal salt marsh at Mont-Saint-Michel Bay in France

Meloidoderita salina sp. n. is described and illustrated from the halophytic plant Atriplex portulacoides L. (sea purslane) growing in a micro-tidal salt marsh in the Mont-Saint-Michel Bay in France. This new species is the first member of Meloidoderita Poghossian, 1966 collected from a saline environment, and is characterized by the following features: sedentary mature females having a small swollen body with a clear posterior protuberance; slightly dorsally curved stylet, 19.9 mu m long, with posteriorly sloping knobs; neck region irregular in shape and twisted; well developed secretory-excretory (S-E) pore, with markedly sclerotized S-E duct running posteriorly; prominent uterus bordered by a thick hyaline wall and filled with eggs. The adult female transforms into a cystoid. Eggs are deposited in both egg-mass and cystoid. Cystoids of Meloidoderita salina sp. n. display a unique sub-cuticular hexagonal beaded pattern. Male without stylet, pharyngeal region degenerated, S-E duct prominent, deirids small, developed testis 97.5 mu m long, spicules 18.4 mu m long, cloacal opening ventrally protruded, small phasmids posterior to cloaca opening and situated at 5.9 (3.2-7.7) mu m from tail end, and conical tail ending in a rounded terminus marked with one (rarely two) ventrally positioned mucro. Additionally, some young males of the new species were observed enveloped in the last J2 cuticle. Second-stage juvenile body 470 mu m long, with a 16.4 mu m long stylet, prominent rounded knobs set off from the shaft, hemizonid anterior and adjacent to S-E pore, small deirids located just above S-E pore level, genital primordium located at 68-77% of body length, phasmids small and located at about 19 mu m from tail tip, and tail 38.7 mu m long, tapering to finely pointed terminus with a finger-like projection. Phylogenetic analyses based on the nearly full length small subunit ribosomal DNA sequences of Meloidoderita salina sp. n. revealed a close relationship of the new species with Sphaeronema alni Turkina & Chizhov, 1986 and placed these two species sister to the rest of Criconematina

Ecology and Evolution of Soil Nematode Chemotaxis

Plants influence the behavior of and modify community composition of soil-dwelling organisms through the exudation of organic molecules. Given the chemical complexity of the soil matrix, soil-dwelling organisms have evolved the ability to detect and respond to these cues for successful foraging. A key question is how specific these responses are and how they may evolve. Here, we review and discuss the ecology and evolution of chemotaxis of soil nematodes. Soil nematodes are a group of diverse functional and taxonomic types, which may reveal a variety of responses. We predicted that nematodes of different feeding guilds use host-specific cues for chemotaxis. However, the examination of a comprehensive nematode phylogeny revealed that distantly related nematodes, and nematodes from different feeding guilds, can exploit the same signals for positive orientation. Carbon dioxide (CO2), which is ubiquitous in soil and indicates biological activity, is widely used as such a cue. The use of the same signals by a variety of species and species groups suggests that parts of the chemo-sensory machinery have remained highly conserved during the radiation of nematodes. However, besides CO2, many other chemical compounds, belonging to different chemical classes, have been shown to induce chemotaxis in nematodes. Plants surrounded by a complex nematode community, including beneficial entomopathogenic nematodes, plant-parasitic nematodes, as well as microbial feeders, are thus under diffuse selection for producing specific molecules in the rhizosphere that maximize their fitness. However, it is largely unknown how selection may operate and how belowground signaling may evolve. Given the paucity of data for certain groups of nematodes, future work is needed to better understand the evolutionary mechanisms of communication between plant roots and soil biot

Hand disinfection in a neonatal intensive care unit: continuous electronic monitoring over a one-year period

<p>Abstract</p> <p>Background</p> <p>Good hand hygiene compliance is essential to prevent nosocomial infections in healthcare settings. Direct observation of hand hygiene compliance is the gold standard but is time consuming. An electronic dispenser with built-in wireless recording equipment allows continuous monitoring of its usage. The purpose of this study was to monitor the use of alcohol-based hand rub dispensers with a built-in electronic counter in a neonatal intensive care unit (NICU) setting and to determine compliance with hand hygiene protocols by direct observation.</p> <p>Methods</p> <p>A one-year observational study was conducted at a 27 bed level III NICU at a university hospital. All healthcare workers employed at the NICU participated in the study. The use of bedside dispensers was continuously monitored and compliance with hand hygiene was determined by random direct observations.</p> <p>Results</p> <p>A total of 258,436 hand disinfection events were recorded; i.e. a median (interquartile range) of 697 (559–840) per day. The median (interquartile range) number of hand disinfection events performed per healthcare worker during the day, evening, and night shifts was 13.5 (10.8 - 16.7), 19.8 (16.3 - 24.1), and 16.6 (14.2 - 19.3), respectively. In 65.8% of the 1,168 observations of patient contacts requiring hand hygiene, healthcare workers fully complied with the protocol.</p> <p>Conclusions</p> <p>We conclude that the electronic devices provide useful information on frequency, time, and location of its use, and also reveal trends in hand disinfection events over time. Direct observations offer essential data on compliance with the hand hygiene protocol. In future research, data generated by the electronic devices can be supplementary used to evaluate the effectiveness of hand hygiene promotion campaigns.</p

A Symbiont-Independent Endo-1,4-β-Xylanase from the Plant-Parasitic Nematode Meloidogyne incognita

Substituted xylan polymers constitute a major part of the hemicellulose fraction of plant cell walls, especially in monocotyledons. Endo-1,4-β-xylanases (EC 3.2.1.8) are capable of hydrolyzing substituted xylan polymers into fragments of random size. Many herbivorous animals have evolved inti- mate relationships with endosymbionts to exploit their enzyme complexes for the degradation of xylan. Here, we report the first finding of a functional endo-1,4-β-xylanase gene from an animal. The gene (Mi-xyl1) was found in the obligate plant-parasitic root-knot nematode Meloidogyne incognita, and encodes a protein that is classified as a member of glycosyl hydrolase family 5. The expression of Mi-xyl1 is localized in the subventral esophageal gland cells of the nematode. Previous studies have shown that M. incognita has the ability to degrade cellulose and pectic polysaccha - rides in plant cell walls independent of endosymbionts. Including our current data on Mi-xyll, we show that the endogenous enzyme complex in root-knot nematode secretions targets essentially all major cell wall carbohydrates to facili-diffusible fragments cleaved from cell wall polysaccharides may act as elicitors of specific disease resistance responses to invading pathogens and parasites (Boudart et al. 1998)

Effects of perioperative intravenous omega-3 fatty acids in colon cancer patients:a randomized, double-blind, placebo-controlled clinical trial

Background: The postoperative inflammatory response contributes to tissue healing and recovery but overwhelming inflammation is associated with postoperative complications. n-3 (ω-3) PUFAs modulate inflammatory responses and may help to prevent a proinflammatory cascade. Objectives: We aimed to investigate the effects of perioperative intravenous n-3 PUFAs on inflammatory cytokines in colon cancer surgery. Methods: This study is a randomized, double-blind, placebo-controlled clinical trial. Forty-four patients undergoing elective colon resection for nonmetastasized cancer were randomly assigned to 2 intravenous n-3 PUFA or saline control infusions the night before and the morning after surgery. Blood was sampled at 6 perioperative time points for changes in cytokines in serum and in LPS-stimulated whole blood samples and leukocyte membrane fatty acid profiles. Results: Twenty-three patients received saline and 21 patients received n-3 PUFAs. Patient and operation characteristics were equal between groups, except for open resection (saline n = 5 compared with n-3 PUFA n = 0, P = 0.056). Ex-vivo IL-6 after LPS stimulation was significantly higher in the n-3 PUFA group at the first day after surgery (P = 0.014), but not different at the second day after surgery (P = 0.467). White blood cell count was higher in the n-3 PUFA group at the fourth day after surgery (P = 0.029). There were more patients with infectious complications in the n-3 PUFA group (8 compared with 3, P = 0.036). There were no overall differences in serum IL-6, IL-10, C-reactive protein, and length of stay. The administration of n-3 PUFAs resulted in rapid increases in leukocyte membrane n-3 PUFA content. Conclusions: In the n-3 PUFA group a clear relation with serum and LPS-stimulated cytokines was not found but, unexpectedly, more infectious complications occurred. Caution is thus required with the off-label use of a perioperative intravenous n-3 PUFA emulsion as a standalone infusion in the time sequence reported in the present study in colon resections with primary anastomosis. This trial was registered at clinicaltrials.gov as NCT02231203

Comparative genomics of two inbred lines of the potato cyst nematode Globodera rostochiensis reveals disparate effector family-specific diversification patterns

This work was funded as part of a grant by the Netherlands Organization for Scientific Research (NWO) as part of the Applied and Technical Science domain (TTW) under grant no. 14708. PT: bioinformatics and computational biology analyses were supported by the University of St Andrews Bioinformatics Unit (AMD3BIOINF), funded by Wellcome Trust ISSF award 105621/Z/14/Z.Background: Potato cyst nematodes belong to the most harmful pathogens in potato, and durable management of these parasites largely depends on host-plant resistances. These resistances are pathotype specific. The current Globodera rostochiensis pathotype scheme that defines five pathotypes (Ro1 - Ro5) is both fundamentally and practically of limited value. Hence, resistant potato varieties are used worldwide in a poorly informed manner. Results : We generated two novel reference genomes of G. rostochiensis inbred lines derived from a Ro1 and a Ro5 population. These genome sequences comprise 173 and 189 scaffolds respectively, marking a ≈ 24-fold reduction in fragmentation as compared to the current reference genome. We provide copy number variations for 19 effector families. Four dorsal gland effector families were investigated in more detail. SPRYSECs, known to be implicated in plant defence suppression, constitute by far the most diversified family studied herein with 60 and 99 variants in Ro1 and Ro5 distributed over 18 and 26 scaffolds. In contrast, CLEs, effectors involved in feeding site induction, show strong physical clustering. The 10 and 16 variants cluster on respectively 2 and 1 scaffolds. Given that pathotypes are defined by their effectoromes, we pinpoint the disparate nature of the contributing effector families in terms of sequence diversification and loss and gain of variants. Conclusions : Two novel reference genomes allow for nearly complete inventories of effector diversification and physical organisation within and between pathotypes. Combined with insights we provide on effector family-specific diversification patterns, this constitutes a basis for an effectorome-based virulence scheme for this notorious pathogen.Publisher PDFPeer reviewe

Comparative genomics among cyst nematodes reveals distinct evolutionary histories among effector families and an irregular distribution of effector-associated promoter motifs

JvS, MH and SvdE were supported by a grant from the Applied and Technical Science domain (TTW) of the Netherlands Organization for Scientific Research (NWO) under grant no. 14708. PT received support from the University of St Andrews Bioinformatics Unit (AMD3BIOINF), funded by Wellcome Trust ISSF award 105621/Z/14/Z. MS benefitted from funding by a VENI grant (17282) from the NWO domain Applied and Engineering Sciences.Potato cyst nematodes (PCNs), an umbrella term used for two species, Globodera pallida and G. rostochiensis, belong worldwide to the most harmful pathogens of potato. Pathotype-specific host plant resistances are an essential handle for PCN control. However, the poor delineation of G. pallida pathotypes hampers the efficient use of available host plant resistances. Long-read sequencing technology allowed us to generate a new reference genome of G. pallida population D383 and, as compared to the current reference, the new genome assembly is 42 times less fragmented. For comparison of diversification patterns of six effector families between G. pallida and G. rostochiensis, an additional reference genome was generated for an outgroup, the beet cyst nematode Heterodera schachtii (IRS population). Large evolutionary contrasts in effector family topologies were observed. While VAPs diversified before the split between the three cyst nematode species, the families GLAND5 and GLAND13 only expanded in PCN after their separation from the genus Heterodera. Although DNA motifs in the promoter regions thought to be involved in the orchestration of effector expression ('DOG boxes') were present in all three cyst nematode species, their presence is not a necessity for dorsal gland-produced effectors. Notably, DOG box dosage was only loosely correlated with expression level of individual effector variants. Comparison of the G. pallida genome with those of two other cyst nematodes underlined the fundamental differences in evolutionary history between effector families. Re-sequencing of PCN populations with deviant virulence characteristics will allow for the linking of these characteristics with the composition of the effector repertoire as well as for the mapping of PCN diversification patterns resulting from extreme anthropogenic range expansion.Publisher PDFPeer reviewe