26 research outputs found

    Long-term spatiotemporal stability and dynamic changes in helminth infracommunities of bank voles (Myodes glareolus) in NE Poland

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    Parasites are considered to be an important selective force in host evolution but ecological studies of host-parasite systems are usually short-term providing only snap-shots of what may be dynamic systems. We have conducted four surveys of helminths of bank voles at three ecologically similar woodland sites in NE Poland, spaced over a period of 11 years, to assess the relative importance of temporal and spatial effects on helminth infracommunities. Some measures of infracom- munity structure maintained relative stability: the rank order of prevalence and abundance of Heligmosomum mixtum, Heligmosomoides glareoli and Mastophorus muris changed little between the four surveys. Other measures changed markedly: dynamic changes were evident in Syphacia petrusewiczi which declined to local extinction, while the capillariid Aonchotheca annulosa first appeared in 2002 and then increased in prevalence and abundance over the remaining three surveys. Some species are therefore dynamic and both introductions and extinctions can be expected in ecological time. At higher taxonomic levels and for derived measures, year and host-age effects and their interactions with site are import- ant. Our surveys emphasize that the site of capture is the major determinant of the species contributing to helminth community structure, providing some predictability in these systems

    Long-term spatiotemporal stability and dynamic changes in the haemoparasite community of spiny mice (Acomys dimidiatus) in four montane wadis in the St. Katherine Protectorate, Sinai, Egypt

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    Background: Long-term field studies of parasite communities are rare but provide a powerful insight into the ecological processes shaping host-parasite interactions. The aim of our study was to monitor long-term trends in the haemoparasite communities of spiny mice (Acomys dimidiatus) and to identify the principal factors responsible for changes over a 12 year period. Methods: To this end we sampled four semi-isolated populations of mice (n= 835) in 2000, 2004, 2008 and 2012 in four dry montane valleys (wadis) located in the Sinai Massif, Egypt. Results: Overall 76.2 % of spiny mice carried at least one of the five haemoparasite genera (Babesia, Bartonella, Haemobartonella, Hepatozoon, Trypanosoma) recorded in the study. Prevalence of haemoparasites varied significantly between the sites with the highest overall prevalence in Wadi Tlah and the lowest in W. El Arbaein, and this changed significantly with time. In the first two surveys there was little change in prevalence, but by 2008, when the first signs of a deepening drought in the region had become apparent, prevalence began to drift downwards, and by 2012 prevalence had fallen to the lowest values recorded from all four sites over the entire 12-year period. The overall mean species richness was 1.2 ± 0.03, which peaked in 2004 and then dropped by more than 50 % by 2012. Species richness was highest among mice from Wadi Tlah and peaked in age class 2 mice (young adults). Site was the most significant factor affecting the prevalence of individual parasite species, with Trypanosoma acomys and Hepatozoon sp. occurring mainly in two wadis (W. Tlah & W. Gharaba). In four of the five genera recorded in the study we observed a significant drop in prevalence or/and abundance since 2004, the exception being Hepatozoon sp. Conclusions: During the 12-year-long period of study in the Sinai, we observed dynamic changes and possibly even cycles of prevalence and abundance of infections which differed depending on parasite species. Although the exact reasons cannot be identified at this time, we hypothesize that the effects of a 15-year-long scarcity of rainfall in the local environment and a fall in host densities over the period of study may have been responsible for a drop in transmission rates, possibly by a negative impact on vector survival

    Long-term spatiotemporal stability and dynamic changes in helminth infracommunities of spiny mice (Acomys dimidiatus) in St. Katherine’s Protectorate, Sinai, Egypt

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    The importance of parasites as a selective force in host evolution is a topic of current interest. However, short-term ecological studies of host-parasite systems, on which such studies are usually based, provide only snap-shots of what may be dynamic systems. We report here on four surveys, carried out over a period of 12 years, of helminths of spiny mice (Acomys dimidiatus), the numerically dominant rodents inhabiting the dry montane wadis in the Sinai Peninsula. With host age (age-dependent effects on prevalence and abundance were prominent) and sex (female bias in abundance in helminth diversity and in several taxa including Cestoda) taken into consideration, we focus on the relative importance of temporal and spatial effects on helminth infracommunities. We show that site of capture is the major determinant of prevalence and abundance of species (and higher taxa) contributing to helminth community structure, the only exceptions being Streptopharaus spp. and Dentostomella kuntzi. We provide evidence that most (notably the Spiruroidea, Protospirura muricola, Mastophorus muris and Gongylonema aegypti, but with exceptions among the Oxyuroidae e.g. Syphacia minuta), show elements of temporal-site stability, with rank order of measures among sites remaining similar over successive surveys and hence some elements of predictability in these systems

    Biodiversity of fungi community on Scots pine needles infected of the autumn needle cast

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    Needle casts belong to the fungal diseases of the assimilation apparatus, which affect the success and quality of the renewal of pine stands. The aim of this study was to investigate the diversity of communities of fungi, which occurred on Scots pine needles. Samples were collected in autumn 2015 from Scots pine saplings from Przedborów Forest District (17°58'34'E 51°31'57'N). Material was sequenced for DNA using Ilumina system. The results were compared with the NCBI base sequences. The results show significant dominance of fungi from Ascomycota division. The taxa responsible for the occurrence of Scots pine needle cast disease were also found. In this group, a significant share characterized the following species: Lophodermium pinastri, Cyclaneusma minus, Lophodermium seditiosum, Sydowia polyspora, Cenangium ferruginosum and Beauveria bassiana. The presented research should enhance the knowledge about the diversity of fungi inhabiting pine needles and about the contribution of pathogenic taxa, which can be used in a more efficient use of protective measures in forest management practice

    Effect of the methodology of studies on the structure of the microorganisms communities in the forest soil

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    Two different communities of microorganisms were identified in soils by application of the classical method of fungi isolation (soil dilution, culturing on artificial media, morphotyping) and a molecular method (extraction of the environmental DNA, amplification with universal primers NS1 and NS2, cloning and sequencing of representative clones). No organisms were common to both communities. Apart from rare representatives of the Animalia, communities included single fungus−like Eucarya belonging to the Protista, Class Oomycota, and numerous fungi belonging to Chytridiomycota, Zygomycota, Ascomycota and Basidiomycota orders. In total, 88 species were identified in four soil samples. Fungi were mostly Ascomycota. The classical method was particularly effective in detection of fungi important for creation of phytosanitary conditions of soil, i.e. antagonists (Penicillium, Tolypocladium and Trichoderma) and potential stimulants (dark−pigmented Hormiactis candida, Humicola spp. and Phialophora spp.) of phytopathogens (including the common forest genera Armillaria and Heterobasidion). Application of the classical method allowed the detection of mycorrhizal Ascomycota from the genus Oidiodendron. Application of the molecular method allowed the detection of 13 mycorrhizal Basidiomycota. Although primers NS1 and NS2 were designed from a match with DNA of culturable organisms, they also amplified the DNA of non−culturable organisms. This emphasizes their potential usefulness in studies of the biodiversity of microorganisms in environmental samples. The shortage of reference sequences in the database discourages use of the 18S rDNA region in studies on fungal communities. The studies on the biodiversity of microorganisms need the application of a few independent methods of detection and identification

    Significance of the soil fungi

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    Fungi in soil perform important services related to nutrient cycling, water dynamics and disease suppression. Along with bacteria, they are important as decomposers in the soil food network. Fungi convert hard−to−digest organic material into forms that other organisms can use. They can immobilize or retain nutrients in the soil. Secondary fungal metabolites have the fungistatic properties and are used in biocontrol processes. The hyphae physically binds soil particles together, creating stable aggregates that help increase water infiltration and soil water retention capacity. Fungi help to increase the accumulation of humic−acid rich organic matter that is resistant to degradation and may stay in the soil for hundreds of year

    Goidanichiella sphaerospora, drugie stanowisko na świecie

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    Aspecimen of Goidanichiella sphaerospora was found in Pinus sylvestris forest soil in Międzychód, northwestern Poland (52.601, 15.889883), in October 2009. This is the world’s second record of G. sphaerospora. Bimorphic conidial heads and conidia are reported for the first time. Goidanichiella sphaerospora forms Aspergillus- and Penicillium-like conidial heads. Conidia formed at +24oC are oval to ellipsoidal, often apiculate, smooth, rather thick-walled, hyaline, with one oil drop inside, 3-4 × 2-3 μm. Additional ellipsoidal to cylindrical, thin-walled, 4-6.5 (-8) × 2-3.0 μm conidia are formed only after incubation for at least 7 days at +4oC in darkness.Goidanichiella sphaerospora znaleziono w glebie leśnej, w młodniku Pinus sylvestris, w Międzychodzie (Polska północna, 52.601, 15.889883), w październiku 2009. Jest to drugie stanowisko tego grzyba na świecie. Poprzednio grzyba stwierdzono w glebie leśnej w Japonii. Grzyb tworzy zarodniki konidialne na bimorficznych konidioforach przypominających konidiofory Aspergillus i Penicillium. Wystepują dwa rodzaje zarodników. W temperaturze 24oC, na PDA i SNA , tworzą się konidia, które są owalne do eliptycznych, ostro zakończone u podstawy, gładkie, grubościenne, hialinowe, z jedną kroplą wewnątrz, 3-4 × 2-3 μm. W temperaturze 4oC, przy braku światła, tworzą się dodatkowe konidia, które są eliptyczne do cylindrycznych, cienkościenne, 4-6,5 (-8) × 2-3,0 μm

    Use of ITS1/2 rDNA and 18S rDNA in studies of the forest soil mycobiota

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    The aim of the studies was to check the usefulness of ITS1/2 rDNA and 18S rDNA regions in the molecular investigation of forest soil microbiota structure. Soil studied, originated from a 1−year−old plantation and a 40−year old stand of Scots pine located in Bierzwnik and Międzychów forest districts located 200 km apart. The hypothesis assumed that both approaches lead to the discovery of abundant microbiota communities with different structures and with rare common species. The environmental DNA was extracted with a Power Soil ® DNA Isolation Kit from two soil samples in each site. The ITS1/2 rDNA was amplified with specific primers ITS1 and ewfitsrev 1, and 18S rDNA with universal primers NS1 and NS2. PCR products were cloned into pGEM−T Easy. Inserts were primarily selected in blue/white screening on a X−gal medium. Representative clones were further selected in two separate RFLP analyses with HhaI and BsuRI restriction enzymes. Representative clones purified and sequenced using the Sanger Method in the DNA Research Centre (Poznań). Each sequence was identified to the lowest taxonomic rank. Ninety to 233 clones with DNA of 5−44 taxa including 3−37 taxa of fungi were obtained from 4 samples of soil. After application of ITS1/2 rDNA and 18S rDNA, the fungal DNA was detected respectively in 89,60−100,00% and 11,77−64,8% clones and the number of fungal species detected was respectively 12−37 and 3−19. Fungi were represented by four orders: Chytridiomycota, Zygomycota, Ascomycota and Basidiomycota. Both primers also amplified also DNA of other organisms (mostly from Animalia and Protista Kingdom) represented by 0−9 taxa. If compared, the application of forest soil microbiota structure with ITS1/2 rDNA and 18S rDNA led to detect a lower abundance of fungi and a bigger abundance of other organisms. Considering the higher number of clones and taxa recognized, the region of ITS1/2 rDNA was more effective in the studies of the soil microbiota structure. The region of 18S rDNA was efficient in local detection of Chytridiomycota and Zygomycota and of rare species of fungi from Ascomycota and Basidiomycota. Despite the deficiency of NCBI database the use of the 18S rDNA region in studies on fungal community the region should be included in molecular studies of fungal diversity. It is concluded that studies on the biodiversity of soil microorganisms need the application of a few independent methods of detection and identification

    Populations of Armillaria species in pine plantations in west-central Poland

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    Two diploid isolates of Armillaria gallica and 143 diploid isolates of A. solidipes were obtained from 145 samples of rhizomorphs, fruit bodies and infected wood of sessile oak and Scots pines from 5–10-year-old Scots pine plantations in three Forest Districts located 100–350 km apart in west-central Poland. Based on pairings among the 145 isolates, 18 somatic compatibility groups (genets) of A. solidipes were distinguished in the three plantations. Sequencing of ITS1/2 rDNA of 18 isolates representing the 18 genets delineated four nuclear haplotypes. This suggests that many of the A. solidipes genets are closely related and were possibly established by sib-related basidiospores. With a few exceptions there was general geographical specialization of genets but not haplotypes. Geographical specialization of genets and the dominance of single haplotypes suggest that the A. solidipes population results from clonal rather than sexual reproduction. Sequencing of the ITS1/2 and IGS-1 rDNA showed small nucleotide diversity in ITS1/2 rDNA and much more diversity in IGS-1 rDNA of the isolates of A. solidipes studied. However, none of these regions has sufficient resolution for the clear differentiation of A. solidipes from A. borealis. The sequences of the EF 1-alpha gene showed high interspecific variability in Armillaria species and very low intraspecific variability in A. solidipes. This gene is the most appropriate for reliable identification of biological species and subgroups of Armillaria. Its application is the most useful in ecological and epidemiological studies of Armillaria

    Molecular methods used in studies of diversity of the soil microorganisms

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    Application of the correct methods of study is essential for a proper description and understanding of natural communities of microorganisms and their relationships. Classical methods used for detection and identification of soil microorganisms resulted in underestimation of the microbiota. It has been claimed that classical methods, based mainly on morphology, led to the identification of only 1% of the soil microbiota, usually species that predominate in culture because of their fast growth and abundant sporulation. Molecular methods allow rapid, accurate, sensitive and cost−effective identification and enumeration of microorganisms. They are designed to replace and/or support classical approaches. This review summarizes some of the current and emerging nucleic acid−based molecular approaches used for detection, discrimination and quantification of microbes in the environment, mostly in soil
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