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New Pathogens (new + pathogen)
Selected AbstractsGiardia lamblia intestinalis: a new pathogen with possible link to Kikuchi,Fujimoto disease.INTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 12 2004An additional element in the disease jigsaw Summary A 16-year-old Caucasian girl of Albanian origin was admitted to the hospital complaining of intermittent fever (38 °C) for a week, nausea, vomiting, and abnormal laboratory findings (elevated serum aminotransferases levels AST/ALT 77/40 U/l and erythrocyte sedimentation rate 80 mm/first hour, as well as leukopenia 2.5 × 103/mm3), which were found in a blood examination. Physical examination revealed slight hepatomegaly and splenomegaly, as well as cervical and axillary lymphadenopathy. A diagnostic open lymph node biopsy was performed and Kikuchi,Fujimoto disease (KFD) was established based on the characteristic histological pattern. Other abnormal laboratory findings were C-reactive protein 6.8 mg/dl and serum lactate dehydrogenase 900 U/l. Her history included a diarrhoea syndrome 2 months before the present admission, during the summer holidays, for which she was treated with metronidazole. At that time, characteristic cysts of giardia lamblia intestinalis were observed in the stools. Herein, we present this case hypothesising that the protozoal infection caused by the giardia lamblia intestinalis was probably triggering an immune response leading to KFD. The patient's age in combination with this firstly reported protozoal pathogen, as a triggering agent leading to KFD, consist a very interesting originality. Additionally, some review data is also given. [source] Labyrinthula terrestris: a new pathogen of cool-season turfgrassesMOLECULAR PLANT PATHOLOGY, Issue 6 2007MARY W. OLSEN ABSTRACT A new disease of turfgrass known as rapid blight is caused by Labyrinthula terrestris, a newly described member of the Labyrinthulids. This unusual group of microorganisms previously has been found in marine systems, and L. terrestris is the only member of the genus Labyrinthula known to be a pathogen of terrestrial plants. Members of this genus are defined by the formation of ectoplasmic networks in which the unicellular somatic cells move or ,glide'. Infections of cool-season turfgrasses occur most commonly when they are irrigated with suboptimal irrigation water with elevated salinity. Disease has been observed in 11 states in the United States and in the United Kingdom. A phylogenetic study indicates that isolates from turfgrass in the United States fall firmly within a clade containing other Labyrinthula spp. and that they came from a common lineage. Its rapid emergence as a turfgrass pathogen may coincide with increased use of relatively high-salinity water or reclaimed water for irrigation. L. terrestris is a potential problem in susceptible turfgrass varieties wherever soil salinity is allowed to accumulate as a result of poor soil structure or suboptimal quality irrigation water is used for irrigation. [source] Phytophthora hydropathica, a new pathogen identified from irrigation water, Rhododendron catawbiense and Kalmia latifoliaPLANT PATHOLOGY, Issue 5 2010C. X. Hong A new species of Phytophthora, previously referred to as taxon Dre II, is named Phytophthora hydropathica. It is heterothallic, but all isolates recovered to date are of the A1 compatibility type. Plerotic oospores are produced. Its sporangia are usually obpyriform and are nonpapillate and noncaducous. Isolates of P. hydropathica had nearly identical single-strand conformation polymorphism (SSCP)-based DNA fingerprints that are distinct from those of all existing species. Their closest relatives are P. parsiana and P. irrigata. This new species is able to grow at relatively high temperatures, with an optimum of 30°C and a maximum of 40°C. It was frequently isolated from irrigation water during warm summers. This species caused leaf necrosis and shoot blight of Rhododendron catawbiense and collar rot of Kalmia latifolia at two nurseries where irrigation reservoirs yielded P. hydropathica. Its potential impact on other horticultural crops is discussed. [source] Genome analysis of microorganisms living in amoebae reveals a melting pot of evolutionFEMS MICROBIOLOGY REVIEWS, Issue 3 2010Claire Moliner Abstract Amoebae-resistant microorganisms exhibit a specific lifestyle. Unlike allopatric specialized intracellular pathogens, they have not specialized because they infect the amoebae via amoebal attack and present a sympatric lifestyle with species from different phyla. In this review, we compare the genomes from bacteria (Legionella pneumophila, Legionella drancourtii, Candidatus,Protochlamydia amoebophila,'Rickettsia bellii, Candidatus,Amoebophilus asiaticus') and a virus (mimivirus) that multiply naturally in amoebae. The objective is to highlight the genomic traits characterizing these microorganisms and their niche by comparison with other specialized pathogens. The genome of intra-amoebal microorganisms is significantly larger than that of their relatives, contradicting the genome reduction theory mostly accepted for intracellular pathogens. This is probably due to the fact that they are not specialized and therefore maintain their genome size. Moreover, the presence of many horizontally transferred genes and mobilomes in their genomes suggests that these microorganisms acquired genetic material from their neighbors and amoebal host, thus increasing their genome size. Important features involved in gene transfer and pathogenicity were thus acquired. These characteristics suggest that amoebae constitute a gene melting pot, allowing diverse microorganisms to evolve by the same pathway characterized by gene acquisition, and then either adapt to the intra-amoebal lifestyle or create new pathogens. [source] Where will pathogen inactivation have the greatest impact?ISBT SCIENCE SERIES: THE INTERNATIONAL JOURNAL OF INTRACELLULAR TRANSPORT, Issue 1 2007T. Hervig Blood safety has always been a major task in transfusion medicine. A strategy to obtain this aim should include donor education, donor selection, and testing of blood donations. Pathogen inactivation adds another level of safety. In the fractionation industry, pathogen inactivation methods are mandatory. Several countries also use pathogen-inactivated plasma , from pools or single donors. Concerning the cellular blood components, there is still no method available for red cell concentrates, whereas methods for platelet concentrates are available in some countries and others are in the pipeline for commercialization. The efficiency of the ,old' methods to increase blood safety and the costs of the methods seem to be major obstacles for the introduction of the systems. There are also concerns on product quality and loss of volume during the inactivation process. As the importance of pathogen inactivation is largest in countries with blood donors who carry infections it is impossible to protect against, either due to high incidence of the infection or due to shortage of tests, cost will be a major question when pathogen inactivation is considered. Pathogen inactivation of red cell concentrates will also be a necessity. When pathogen inactivation methods are available for all blood components, they will have great impact to protect the patients in countries where a high percentage of the population is infected by agents transmissible through blood transfusion, and in all situations to protect against new pathogens and ,old' pathogens that become more virulent. The total risk of contracting infectious diseases through blood transfusion will probably be important when implementation of new methods for pathogen inactivation is considered. [source] Introductions of non-native plant pathogens into Great Britain, 1970,2004PLANT PATHOLOGY, Issue 5 2007D. R. Jones An analysis of records of plant pathogens first identified in Great Britain from 1970 to 2004 (inclusive) was undertaken to determine the numbers of new species that have become established over time. Results show that the numbers of newly recorded pathogens have not varied significantly. Of the 234 pathogens recorded for the first time between 1970 and 2004, 157 were fungi, 27 were oomycetes, 26 were viruses, 23 were bacteria, and one was a phytoplasma. Approximately 53% of pathogens were found on ornamental crops, 16% on horticultural crops, 15% on wild native species, 12% on agricultural crops, 2% on pasture plants and 2% on exotic forestry tree species. Where the origin of introductions was known or strongly suspected, 47% came from the Netherlands. About 38% of newly recorded pathogens with information on the location of first record were discovered in the South East region of England. Plant Pathologists regarded 19% of all new pathogens as important because of actual or potential economic/environmental losses. The results indicate that the numbers of new or important pathogens establishing in recent years are not increasing and that most new findings are associated with ornamental plants. [source] The effect of ageing on macrophage Toll-like receptor-mediated responses in the fight against pathogensCLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2010C. R. Dunston Summary The cellular changes during ageing are incompletely understood yet immune system dysfunction is implicated in the age-related decline in health. The acquired immune system shows a functional decline in ability to respond to new pathogens whereas serum levels of cytokines are elevated with age. Despite these age-associated increases in circulating cytokines, the function of aged macrophages is decreased. Pathogen-associated molecular pattern receptors such as Toll-like receptors (TLRs) are vital in the response of macrophages to pathological stimuli. Here we review the evidence for defective TLR signalling in normal ageing. Gene transcription, protein expression and cell surface expression of members of the TLR family of receptors and co-effector molecules do not show a consistent age-dependent change across model systems. However, there is evidence for impaired downstream signalling events, including inhibition of positive and activation of negative modulators of TLR induced signalling events. In this paper we hypothesize that despite a poor inflammatory response via TLR activation, the ineffective clearance of pathogens by macrophages increases the duration of their activation and contributes to perpetuation of inflammatory responses and ageing. [source] | |||||||||||||