Heterogeneous microbial community associated with Bursaphelenchus xylophilus

Pine wilt disease (PWD) is a complex disease integrating three major factors: the causal agent, the pinewood nematode Bursaphelenchus xylophilus; the insect-vector Monochamus spp.; and the host pine tree, Pinus sp. Since the early 80’s, the notion that another pathogenic agent involved, namely bacteria, may play a role in PWD has been gaining traction, however the role of bacteria in PWD is still unknown. The present work suggests the intriguing possibility that some B. xylophilus-associated bacteria may play a significant role in the development of this disease. This is inferred as a consequence of: (i) the phenotypic characterization, of a collection of 35 isolates of B. xylophilus-associated bacteria, in different tests broadly used to test plant pathogenic and plant growth promoting bacteria, and (ii) greenhouse experiments that infer pathogenicity of these bacteria in in maritime pine, Pinus pinaster. The results illustrate the presence of a heterogeneous microbial community associated with B. xylophilus and the traits exhibited by at least some of these bacteria appear to be related to PWD symptoms. The inoculation of four specific B. xylophilus-associated bacteria in P. pinaster seedlings resulted in the development of some PWD symptoms suggesting that these bacteria likely play an active role with B. xylophilus in PWD

The role of Bursaphelenchus xylophilus associated bacteria in pine wilt disease

Pine wilt disease (PWD) is a complex disease integrating three major factors: the causal agent, the pinewood nematode Bursaphelenchus xylophilus; the insect-vector Monochamus spp.; and the host pine tree, Pinus sp. Since the early 80’s, the notion that another pathogenic agent involved, namely bacteria, may play a role in PWD has been gaining traction, however the role of bacteria in PWD is still unknown. The present work suggests the intriguing possibility that some B. xylophilus-associated bacteria may play a significant role in the development of this disease. This is inferred as a consequence of: (i) the phenotypic characterization, of a collection of 35 isolates of B. xylophilus-associated bacteria, in different tests broadly used to test plant pathogenic and plant growth promoting bacteria, and (ii) greenhouse experiments that infer pathogenicity of these bacteria in in maritime pine, Pinus pinaster. The results illustrate the presence of a heterogeneous microbial community associated with B. xylophilus and the traits exhibited by at least some of these bacteria appear to be related to PWD symptoms. The inoculation of four specific B. xylophilus-associated bacteria in P. pinaster seedlings resulted in the development of some PWD symptoms suggesting that these bacteria likely play an active role with B. xylophilus in PWD

Mikroorganismen an Aesculus hippocastanum – olfaktorische Perspektive von Cameraria ohridella (Deschka & Dimic)

Since the 80s, the popular park- and city tree Aesculus hippocastanum has been infested with the leaf miner Cameraria ohridella (DESCHKA & DIMIC 1986). Additionally, the pathogenic fungi Guignardia aesculi causes leaf blotch disease and Erysiphe flexuosa causes powdery mildew on horse chestnuts. Often, all three diseases occur in parallel at the same leaves leading to a situation of competition. Moreover, recently some endophytic fungi were isolated from the leaf tissue of A. hippocastanum. In the present study, the volatile interaction between three trophic levels plant, insect, and fungi are discussed.Mikroorganismen an Aesculus hippocastanum – olfaktorische Perspektive von Cameraria ohridella (Deschka & Dimic) Seit den 80er Jahren wird die Gemeine Rosskastanie Aesculus hippocastanum durch den Minierer Cameraria ohridella (Lepidoptera, Gracillariidae) befallen. Außerdem wird die Rosskastanie durch den Blattbräunepilz Guignardia aesculi und den Mehltau Erysiphe flexuosa attackiert. Oft treten alle drei Organismen parallel am gleichen Blatt auf. Weiterhin konnten endophytische Pilze aus dem Blattgewebe isoliert werden. Im vorliegenden Beitrag wird die volatile Interaktion zwischen Pflanze, Mikroorganismen und Insekt diskutiert. Mit Hilfe der Gaschromatographie und gekoppelter Massenspektroskopie (GC-MS) wurden Duftproben gesunder und mit den pathogenen Pilzen G. aesculi und E. flexuosa gleichzeitig infizierter Blätter der Rosskastanie analysiert. Identifizierte Komponenten wurden elektrophysiologisch (EAG) an der Insektenantenne und in Verhaltensversuchen getestet. Mit den pathogenen Pilzen befallene Rosskastanienblätter geben 1-Octen-3-ol, 3-Octanon, ein Derivat von 2(5H)-Furanon, Nonanal und Decanal ab. C. ohridella war in der Lage, diese Substanzen zu detektieren. In Zweifachwahltests mit gesunden A. hippocastanum Zweigen reagierten Weibchen mit reduzierter Eiablage auf die Applikation von 1-Octen-3-ol, 3-Octanon, 2(5H)-Furanon und Decanal im Vergleich zur unbehandelten Kontrolle. Es ist bekannt, dass 1-Octen-3-ol und 3-Octanon von Pilzen selber emittiert werden. Nonanal und Decanal werden von Zellen, die nach Penetration durch Pilzhyphen unter oxidativem Stress stehen, produziert. Die Derivate von 2(5H)-Furanon wirken antimikrobiell und können auf einen Schutzmechanismus der Pflanze oder auf einen Konkurrenzmechanismus von Mikroorganismen um denselben Lebensraum hinweisen. Eine mögliche Erklärung wäre, dass diese Substanz von Endophyten zur Verteidigung des sie umgebenden Blattgewebes gegen die pathogenen Pilze produziert wird

Some potential occupational and environmental hazards associated with fish pond production in Nigeria

The paper highlights the concept of information and the significance of environmental and occupational hazards associated with pond fish production in Nigeria and discuss the possible options for the ways forward. The major raw material used in fish production system is the organic manure (cow dung, poultry droppings, porcine manure etc) that serves as substrate for heterotrophic production of bacteria and protozoa, which act as food for zooplankton and the fish. The pathogenic organisms (viruses, bacteria, protozoa's, and parasites), are noted for the potential hazard to the fish handlers and consumers. Nine species from seven genera of bacteria associated with fish diseases are found to have association with diseases of human such as typhoid fever, bacillary dysentery and other gastrointestinal tract related problems. Also the environmental contaminants in pond fish production become important because of its significance to consumers' acceptance of the fish product

Morphological, Pathogenic and Toxigenic Variability in the Rice Sheath Rot Pathogen Sarocladium Oryzae

Sheath rot is an emerging rice disease that leads to considerable yield losses. The main causal agent is the fungus Sarocladium oryzae. This pathogen is known to produce the toxins cerulenin and helvolic acid, but their role in pathogenicity has not been clearly established. S. oryzea isolates from different rice-producing regions can be grouped into three phylogenetic lineages. When grown in vitro, isolates from these lineages differed in growth rate, colour and in the ability to form sectors. A diverse selection of isolates from Rwanda and Nigeria, representing these lineages, were used to further study their pathogenicity and toxin production. Liquid chromatography high-resolution mass spectrometry analysis was used to measure cerulenin and helvolic acid production in vitro and in planta. The three lineages clearly differed in pathogenicity on the japonica cultivar Kitaake. Isolates from the least pathogenic lineage produced the highest levels of cerulenin in vitro. Helvolic acid production was not correlated with the lineage. Sectorisation was observed in isolates from the two least pathogenic lineages and resulted in a loss of helvolic acid production. In planta, only the production of helvolic acid, but not of cerulenin, correlated strongly with disease severity. The most pathogenic isolates all belonged to one lineage. They were phenotypically stable, shown by the lack of sectorisation, and therefore maintained high helvolic acid production in planta

The health significance of heterotrophic bacteria in drinking water

Tap water is not sterile; it contains organisms which grow in water distribution systems or inside taps and their fittings. The absence of known pathogenic bacteria is assured by the absence of the indicator organisms but concerns have been raised in the past few years that drinking water fulfilling the standards laid down in the EC Directive ECC 80/778 may still cause disease. These concerns have arisen from several sources: the fact that a cause has been identified in only half of all suspected waterborne outbreaks of disease; reports have suggested that heterotrophic bacteria possessing single pathogenic mechanisms such as haemolysin may cause disease; reports of heterotrophic organisms causing water contact diseases in hospitals. These concerns led to a reappraisal of the pathogenic potential of heteretrophic bacteria, by carrying out an extensive literature search and review commissioned by the UK Water Research Company. This research identified many papers showing an association between drinking water and heterotrophic bacteria but only very few reports of suspected waterborne disease associated with the heterotrophs. The organisms demonstrating potential to cause disease were species of Aeromonas and Yersinia, but typing of organisms identified in patients and isolated from the water revealed very few similarities. The potential of Aeromonas and Yersinia to cause waterborne disease is thought to be very low and the Communicable Disease Surveillance Centre database of laboratory infections due to these two genera of organisms was analysed to produce population-related incidences for each health region in England and Wales. Additionally a laboratory questionnaire revealed different levels of ascertainment of these two organisms in different laboratories of the Public Health Laboratory Service

The Infectious Disease Ontology in the Age of COVID-19

The Infectious Disease Ontology (IDO) is a suite of interoperable ontology modules that aims to provide coverage of all aspects of the infectious disease domain, including biomedical research, clinical care, and public health. IDO Core is designed to be a disease and pathogen neutral ontology, covering just those types of entities and relations that are relevant to infectious diseases generally. IDO Core is then extended by a collection of ontology modules focusing on specific diseases and pathogens. In this paper we present applications of IDO Core within various areas of infectious disease research, together with an overview of all IDO extension ontologies and the methodology on the basis of which they are built. We also survey recent developments involving IDO, including the creation of IDO Virus; the Coronaviruses Infectious Disease Ontology (CIDO); and an extension of CIDO focused on COVID-19 (IDO-CovID-19).We also discuss how these ontologies might assist in information-driven efforts to deal with the ongoing COVID-19 pandemic, to accelerate data discovery in the early stages of future pandemics, and to promote reproducibility of infectious disease research

Bird flu, avian influenza : the H5N1 virus, poultry, other animals, and people here and elsewhere, from Asia to Africa

Illustré d'une trentaine de photographies originales issues des missions de terrain des vétérinaires et ornithologues du Cirad dans les pays du Sud, le livret fait le point sur ce fléau qui a d'abord frappé les pays du Sud-Est asiatique depuis 1997, avant de gagner l'Europe puis l'Afrique au début 2006. La version anglaise apporte plusieurs éléments nouveaux. L'Inra s'ajoute aux neuf institutions partenaires de l'édition française. Les recherches, conduites dans ce domaine par l'institut, sont mentionnées en page 41 du livret. On trouve également, en page 42, le bilan des opérations de surveillance menées au cours de l'année 2006 dans diverses zones d'implantation des oiseaux sauvages. En pages 33 et 34, les cartes des pays touchés par le virus H5N1 ont été actualisées. Il en est de même concernant la rubrique " Pour en savoir beaucoup plus ", fournissant, en fin de livret, de nouvelles sources d'information accessibles sur le web