Phylogenetic analysis and characterization of a new parasitic cnidarian (Myxosporea: Myxobolidae) parasitizing skin of the giant mottled eel from the Solomon Islands

Myxosporeans are microscopic cnidarians associated with severe diseases in aquaculture and wild fish populations. This group of parasitic cnidarians thus warrants close attention concerning its potential impact on susceptible fish stocks. At present, little is known about this group of parasites infecting anguillid eels. From myxospore specimens collected from a freshwater eel (Anguilla marmorata) in the Solomon Islands, we describe a new species belonging to the genus Myxobolus based on an integrative taxonomic analysis of morphological, biological traits and molecular data. Furthermore, we determined the phylogenetic position and relationships of this species among other platysporine myxosporeans. Molecular phylogenetic assessment of small subunit ribosomal DNA showed that the species clusters together with Myxobolus portucalensis and Echinactinomyxon type 5 Özer, Wootten and Shinn, 2002, in a well-supported subclade. This is the first report of a myxosporean parasite infecting fish from the Solomon Islands.

Integrated assessment of the spatial distribution and structural dynamics of deep benthic marine communities

Characterizing the spatial distribution and variation of species communities and validating these characteristics with data from the field are key elements for an ecosystem-based approach to management. However, models of species distributions that yield community structure are usually not linked to models of community dynamics, constraining understanding and management of the ecosystem, particularly in data-poor regions. Here we use a qualitative network model to predict changes in Antarctic benthic community structure between major marine habitats characterized largely by seafloor depth and slope, and use multivariate mixture models of species distributions to validate the community dynamics. We then assess how future increases in primary production associated with anticipated loss of sea-ice may affect the ecosystem. Our study shows how both spatial and structural features of ecosystems in data-poor regions can be analyzed and possible futures assessed, with direct relevance for ecosystem-based management.

New gSSR and EST-SSR markers reveal high genetic diversity in the invasive plant Ambrosia artemisiifolia L. and can be transferred to other invasive Ambrosia species

Ambrosia artemisiifolia L., (common ragweed), is an annual invasive and highly troublesome plant species originating from North America that has become widespread across Europe. New sets of genomic and expressed sequence tag (EST) based simple sequence repeats (SSRs) markers were developed in this species using three approaches. After validation, 13 genomic SSRs and 13 EST-SSRs were retained and used to characterize the genetic diversity and population genetic structure of Ambrosia artemisiifolia populations from the native (North America) and invasive (Europe) ranges of the species. Analysing the mating system based on maternal families did not reveal any departure from complete allogamy and excess homozygosity was mostly due the presence of null alleles. High genetic diversity and patterns of genetic structure in Europe suggest two main introduction events followed by secondary colonization events. Cross-species transferability of the newly developed markers to other invasive species of the Ambrosia genus was assessed. Sixty-five percent and 75% of markers, respectively, were transferable from A. artemisiifolia to Ambrosia psilostachya and Ambrosia tenuifolia. 40% were transferable to Ambrosia trifida, this latter species being seemingly more phylogenetically distantly related to A. artemisiifolia than the former two.

Lost in the North: The first record of Diretmichthys parini (Post and Quéro, 1981) in the northern North Sea

In June 2015, an individual of Diretmichthys parini (Post and Quero, 1981) was trawled at 530m depth, in the North Sea off Norway and donated to research. This capture, the first for this species in the North Sea was the northernmost recorded so far, and provided an opportunity to document some aspects of the biology and ecology of this data-poor species. This individual was a female, 331mm total length of 33years old, with low mercury content in muscle and liver (~0.2μgg^-1 wet mass). Stable isotope ratios (C and N) in muscle and liver were consistent with the planktonic diet expected for this species. The capture of this fish at the northern latitude known so far would be consistent with the extension of the home range and the latitudinal shift hypothesized for this species in the 1990's.

Redescription of the Indo-Pacific scorpionfish Scorpaenodes guamensis (Quoy & Gaimard 1824) (Scorpaenidae), a senior synonym of seven nominal species

The Indo-Pacific scorpionfish, Scorpaenodes guamensis (Quoy & Gaimard 1824), is redescribed on the basis of 137 specimens, including types, from a wide geographic range in the Indo-Pacific. Seven nominal species, Scorpaena rubropunctata Cuvier in Cuvier & Valenciennes 1829, Sebastes minutus Cuvier in Cuvier & Valenciennes 1829, Scorpaena chilioprista Rüppell 1838, Scorpaena polylepis Bleeker 1851, Centropogon echinatus Macleay 1881, Scorpaena erinacea Garman 1903, and Scorpaenopsis quiescens Seale 1906, are regarded here as junior synonyms of S. guamensis. The type status of these nominal species is discussed, and lectotypes of Scorpaena guamensis, Scorpaena rubropunctata, Sebastes minutus, and Scorpaena polylepis are herein designated. Validity of Scorpaenopsis scaber (Ramsay & Ogilby 1886) is also discussed.

Genetic basis, evolutionary origin and spread of resistance to herbicides inhibiting acetolactate synthase in common groundsel (Senecio vulgaris)

BACKGROUND

Following control failure by herbicides inhibiting acetolactate synthase (ALS) in French wheat fields and vineyards, we aimed to confirm resistance evolution and investigate the evolutionary origin and spread of resistance in the tetraploid species Senecio vulgaris (common groundsel), a widespread, highly mobile weed.

RESULTS

Sequencing of two ALS homeologues in S. vulgaris enabled the first identification and characterisation of ALS-based resistance in this species. Cross-resistance patterns associated with Leu-197 and Ser-197 ALS1 were established using eight herbicides. Sequencing and genotyping showed that ALS-based resistance evolved by multiple, independent appearances of mutant ALS1 and ALS2 alleles followed by spread. Spread of a mutant ALS1 allele issued from one particular appearance event was observed over 60 km. Independent resistance appearance events and easy seed dispersion are the most likely reasons for populations of S. vulgaris containing different mutant ALS alleles. Accumulation of different alleles probably due to sexual reproduction was observed in the same plant.

CONCLUSION

Mutant ALS alleles and possibly other mechanisms cause resistance to ALS inhibitors in S. vulgaris. Management strategies should aim at limiting S. vulgaris establishment and seed set. Considering the mobility of this species, control coordination at a regional level is clearly necessary if resistance spread is to be contained.

Redescription of the Indo-West Pacific scorpionfish (Scorpaenidae), Neomerinthe erostris (Alcock 1896), a senior synonym of Scorpaena gibbifrons Fowler 1938, N. rotunda Chen 1981, and N. bathyperimensis Zajonz & Klausewitz 2002

The Indo-West Pacific species, Neomerinthe erostris (Alcock 1896), originally described as Scorpaena erostris, is redescribed as a senior synonym of Scorpaena gibbifrons Fowler 1938, N. rotunda Chen 1981, and N. bathyperimensis Zajonz & Klausewitz 2002. Although the latter three nominal species have been regarded as valid species and N. erostris has not been reported since 1898, examinations of type specimens of the four nominal species revealed that they represent a single species. A lectotype of Scorpaena erostris is herein designated. Neomerinthe erostris is characterized by having a distinct longitudinal ridge on the lateral surface of the maxilla and a strongly rounded dorsal profile of the head.

A new deep-water goatfish of the genus Upeneus (Mullidae) from Vanuatu, South Pacific

A new goatfish, Upeneus vanuatu (Mullidae), is described based on five specimens collected off two islands of Vanuatu (South Pacific), at depths of 191-321 m, and compared with five closely related species: Upeneus davidaroni (Red Sea), U. mascareinsis (Western Indian Ocean), U. stenopsis (northern Australia, Philippines, 127-275 m), and the more shallow-occurring Indo-West Pacific species U. subvittatus (26-120 m) and U. vittatus (<l00 m). The new species can be distinguished from all other congeneric species by the combination of four characters: number of gill rakers on lower limb, caudal-peduncle depth, interorbital length, and interdorsal distance. Strong allometric variation in body form between the holotype and the four smaller paratypes was found. Based on the lack of lateral body stripes, a rather narrow caudal peduncle depth, and large eyes in adults as common characteristics for U. subvittatus and the four deep-water Upeneus species, the so-called "stenopsis" species group can be distinguished from four other species groups that were established in earlier studies in order to facilitate intrageneric comparisons. The ecological and evolutionary significance of deep-water goatfishes is briefly discussed.

Non-invasive ancient DNA protocol for fluid-preserved specimens and phylogenetic systematics of the genus Orestias (Teleostei: Cyprinodontidae)

Specimens stored in museum collections represent a crucial source of morphological and genetic information, notably for taxonomically problematic groups and extinct taxa. Although fluid-preserved specimens of groups such as teleosts may constitute an almost infinite source of DNA, few ancient DNA protocols have been applied to such material. In this study, we describe a non-invasive Guanidine-based (GuSCN) ancient DNA extraction protocol adapted to fluid-preserved specimens that we use to re-assess the systematics of the genus Orestias (Cyprinodontidae: Teleostei). The latter regroups pupfishes endemic to the inter-Andean basin that have been considered as a 'species flock', and for which the morphology-based taxonomic delimitations have been hotly debated. We extracted DNA from the type specimens of Orestias kept at the Muséum National d'Histoire Naturelle of Paris, France, including the extinct species O. cuvieri. We then built the first molecular (control region [CR] and rhodopsin [RH]) phylogeny including historical and recently collected representatives of all the Orestias complexes as recognized by Parenti (1984a): agassizii, cuvieri, gilsoni and mulleri. Our ancient DNA extraction protocol was validated after PCR amplification through an approach based on fragment-by-fragment chimera detection. After optimization, we were able to amplify < 200 bp fragments from both mitochondrial and nuclear DNA (CR and RH, respectively) from probably formalin-fixed type specimens bathed entirely in the extraction fluid. Most of the individuals exhibited few modifications of their external structures after GuSCN bath. Our approach combining type material and 'fresh' specimens allowed us to taxonomically delineate four clades recovered from the well-resolved CR tree into four redefined complexes: agassizii (sensu stricto, i.e. excluding luteus-like species), luteus, cuvieri and gilsoni. The mulleri complex is polyphyletic. Our phylogenetic analyses based on both mitochondrial and nuclear DNA revealed a main, deep dichotomy within the genus Orestias, separating the agassizii complex from a clade grouped under shallow dichotomies as (luteus, (cuvieri, gilsoni)). This 'deep and shallow' diversification pattern could fit within a scenario of ancient divergence between the agassizii complex and the rest of Orestias, followed by a recent diversification or adaptive radiation within each complex during the Pleistocene, in- and outside the Lake Titicaca. We could not recover the reciprocal monophyly of any of the 15 species or morphotypes that were considered in our analyses, possibly due to incomplete lineage sorting and/or hybridization events. As a consequence, our results starkly question the delineation of a series of diagnostic characters listed in the literature for Orestias. Although not included in our phylogenetic analysis, the syntype of O. jussiei could not be assigned to the agassizii complex as newly defined. The CR sequence of the extinct O. cuvieri was recovered within the cuvieri clade (same haplotype as one representative of O. pentlandii), so the mtDNA of the former species might still be represented in the wild.

Using next-generation sequencing to detect mutations endowing resistance to pesticides: application to acetolactate-synthase (ALS)-based resistance in barnyard grass, a polyploid grass weed

BACKGROUND

Next-generation sequencing (NGS) technologies offer tremendous possibilities for accurate detection of mutations endowing pesticide resistance, yet their use for this purpose has not emerged in crop protection. This study aims at promoting NGS use for pesticide resistance diagnosis. It describes a simple procedure accessible to virtually any scientist and implementing freely accessible programs for the analysis of NGS data.

RESULTS

Three PCR amplicons encompassing seven codons of the acetolactate-synthase gene crucial for herbicide resistance were sequenced using non-quantified pools of crude DNA extracts from 40 plants in each of 28 field populations of barnyard grass, a polyploid weed. A total of 63,959 quality NGS sequence runs were obtained using the 454 technology. Three herbicide-resistance-endowing mutations (Pro-197-Ser, Pro-197-Leu and/or Trp-574-Leu) were identified in seven populations. The NGS results were confirmed by individual plant Sanger sequencing.

CONCLUSION

This work demonstrated the feasibility of NGS-based detection of pesticide resistance, and the advantages of NGS compared with other molecular biology techniques for analysing large numbers of individuals. NGS-based resistance diagnosis has the potential to play a substantial role in monitoring resistance, maintaining pesticide efficacy and optimising pesticide applications.

Is the species flock concept operational? The Antarctic shelf case

There has been a significant body of literature on species flock definition but not so much about practical means to appraise them. We here apply the five criteria of Eastman and McCune for detecting species flocks in four taxonomic components of the benthic fauna of the Antarctic shelf: teleost fishes, crinoids (feather stars), echinoids (sea urchins) and crustacean arthropods. Practical limitations led us to prioritize the three historical criteria (endemicity, monophyly, species richness) over the two ecological ones (ecological diversity and habitat dominance). We propose a new protocol which includes an iterative fine-tuning of the monophyly and endemicity criteria in order to discover unsuspected flocks. As a result nine « full » species flocks (fulfilling the five criteria) are briefly described. Eight other flocks fit the three historical criteria but need to be further investigated from the ecological point of view (here called "core flocks"). The approach also shows that some candidate taxonomic components are no species flocks at all. The present study contradicts the paradigm that marine species flocks are rare. The hypothesis according to which the Antarctic shelf acts as a species flocks generator is supported, and the approach indicates paths for further ecological studies and may serve as a starting point to investigate the processes leading to flock-like patterning of biodiversity.

Cryptic diversity in Indo-Pacific coral-reef fishes revealed by DNA-barcoding provides new support to the centre-of-overlap hypothesis

Diversity in coral reef fishes is not evenly distributed and tends to accumulate in the Indo-Malay-Philippines Archipelago (IMPA). The comprehension of the mechanisms that initiated this pattern is in its infancy despite its importance for the conservation of coral reefs. Considering the IMPA either as an area of overlap or a cradle of marine biodiversity, the hypotheses proposed to account for this pattern rely on extant knowledge about taxonomy and species range distribution. The recent large-scale use of standard molecular data (DNA barcoding), however, has revealed the importance of taking into account cryptic diversity when assessing tropical biodiversity. We DNA barcoded 2276 specimens belonging to 668 coral reef fish species through a collaborative effort conducted concomitantly in both Indian and Pacific oceans to appraise the importance of cryptic diversity in species with an Indo-Pacific distribution range. Of the 141 species sampled on each side of the IMPA, 62 presented no spatial structure whereas 67 exhibited divergent lineages on each side of the IMPA with K2P distances ranging between 1% and 12%, and 12 presented several lineages with K2P distances ranging between 3% and 22%. Thus, from this initial pool of 141 nominal species with Indo-Pacific distribution, 79 dissolved into 165 biological units among which 162 were found in a single ocean. This result is consistent with the view that the IMPA accumulates diversity as a consequence of its geological history, its location on the junction between the two main tropical oceans and the presence of a land bridge during glacial times in the IMPA that fostered allopatric divergence and secondary contacts between the Indian and Pacific oceans.

Impact of a multidisciplinary approach to the control of antibiotic prescription in a general hospital

We examined the impact of a rational antibiotic prescription programme based on a multidisciplinary consultative approach in a 600-bed hospital. The programme involved four measures: (1). drawing up of a local prescribing consensus with all prescribers; (2). a restricted prescriptions policy for the most expensive antibiotics; (3.assessment of the prescription of these antibiotics by regular audits; and (4). institutional training and information for prescribers. The impact of the programme was assessed by comparing actual prescriptions with the criteria of the local consensus, compliance with the restrictive prescription policy, changes in the average daily cost of antibiotic therapy per inpatient and changes in the local ecology of methicillin-resistant Staphylococcus aureus (MRSA), Enterobacteriaceae producing extended-spectrum beta-lactamases (EPESB) and ceftazidime-resistant Pseudomonas species (CRP). Using a participatory consensual approach, 182 reference recommendations were established (104 for adults, 78 for children), corresponding to 85% of the clinical settings encountered in the hospital. Six audits, conducted since June 1997, show that the rate of unjustified prescriptions first fell significantly (from 6 to 0%, P<0.001), then increased significantly (from 0 to 3%, P<0.05) before stabilizing at 3%. The cost of antimicrobials per inpatient day fell significantly (from US dollars 13.8 in 1997 to US dollars 11 in 2000, P<0.001). The prevalence of MRSA and CRP remained stable, while that of EPESB fell significantly (P<0.001). This multidisciplinary consultative approach thus reduced antibiotic costs, contributed to infection control, and improved the quality of antibiotic prescription.

[Analysis of mode of failure, their effects and criticality: improving of the hospital drug prescribing process]

Failure Mode, Effects, and Criticality Analysis (FMECA) is used in industry to prevent process or product failures. We studied the feasibility of this method in hospital organizations. FMECA was used to improve drug prescription in two medical wards. Failure modes were identified and classified hierarchically. Corrective actions were taken. Involvement of all the professionals concerned in this process was obtained, and has resulted in real acceptance of the proposed changes and in their effective realization.

[Evaluation of low molecular weight heparin prescription at the Centre Hospitalier Intercommunal de Créteil]

Low-molecular-weight heparin (LMWH) represents a great expense in general hospitals. At the Centre Hospitalier Intercommunal de Créteil (CHIC), the Quality Assessment Council had set up a study on the prescription of LMWH in order to assess concordance between prescriptions and local guidelines on the preventive uses of LMWH. Adherence to the consensus was found in 73 per cent of cases, overprescription in 10 per cent of cases and underprescription in 26 per cent of cases. It is planned to modify the local consensus, taking into account some clinical situations highlighted by this study, and to perform another evaluation in the near future.

[Impact of a multidisciplinary approach for monitoring prescribing of antibiotics in a hospital]

OBJECTIVE

The aim of this study was to examine the impact of a rationalized antibiotic prescription program in a 600-bed hospital.

PATIENTS AND METHODS

The program was based on a local consensus policy, developed with the prescribers themselves, together with individual nominative dispensing (IDN) of the most costly antibiotics, and training/information programs aimed at institutional prescribers. The impact of the program was assessed in terms of the relevance of prescriptions (6-monthly audits), changes in the overall cost of anti-infectives, the average daily cost per hospital patient, and changes in the pattern of antimicrobial resistance among pathogens isolated in the institution.

RESULTS

Reference recommendations were established for most clinical settings encountered in the hospital (104 for adults, 78 for children). The four audits conducted since June 1996 show that the rate of unjustified prescriptions has remained below 6%. The cost of antimicrobials has fallen regularly, both in absolute terms and as a proportion of total drug costs. Finally, resistance rates among the different pathogens studied have fallen or remained stable.

CONCLUSION

Rationalization of antimicrobial chemotherapy in a short-stay hospital necessitates an institution-based policy with long-term objectives, a large initial investment and, above all, a participative approach among all prescribers.