Tissue specificities of Thelohania duorara,Agmasoma penaei, and Pleistophora sp., microsporidian parasites of pink shrimp, Penaeus duorarum

The pathology of pink shrimp, Penaeus duorarum, infected with the microsporidians Thelohania duorara, Agmasoma penaei, and Pleistophora sp. was described. Infections of T. duorara were widespread in most tissues; spores were located throughout the hemocoel, at the periphery of all striated muscle bundles, and in muscle and connective tissue surrounding the digestive tract. A. penaei infections invaded only dorsal abdominal muscles, muscles adjacent to blood vessels, and ovaries. Infected muscles and ovaries were eventually completely destroyed. Masses of A. penaei spores were often engulfed by hemocytes. Pleistophora sp. infected the interior of all striated muscles. Infected muscles were never completely destroyed but were often atrophied.     

Benthic foraminifera associated with the invasive ascidian, Didemnum sp. A

The invasive ascidian, Didemnum sp. A, first appeared in New England bays and harbors in the early 1990s, and in the waters around Cape Cod in 1993. While ship traffic was the likely vector introducing the species, its origin and precise date and location of its introduction are presently unknown. Colony surfaces of Didemnum sp. A appear very clean and not favorable substrates for epibiota settlement, but closer inspection revealed the presence of benthic foraminifera. During 2003 and 2004, 52 samples of Didemnum sp. A and other ascidians were collected to determine whether or not the foraminiferal assemblages might also be non-native and thus provide a potential clue to the place of origin of Didemnum sp. A. Sample locations included the New England coast from Connecticut to Maine (with a concentration in the Cape Cod area), northern California, Zeeland, The Netherlands, and Shakespeare Bay, New Zealand. From New England samples, 18 species of benthic foraminifera were identified. The most common species represented were Cornuspira involvens, C. planorbis, Elphidium galvestonense, E. margaritaceum, Glabratellina lauriei, Miliolinella subrotunda, Quinqueloculina bicornis, and Rosalina floridana. Foraminiferal assemblages on Didemnum sp. A from other regions sampled were composed of the same cosmopolitan species found in New England, plus other species which were indigenous to each region. Because no exotic foraminifera species were found it is concluded that Didemnum sp. A likely did not introduce non-native foraminifera originating from their native habitats into the New England region.     

The life cycle and host specificity of Psychodiella sergenti n. sp. and Ps. tobbi n. sp. (Protozoa: Apicomplexa) in sand flies Phlebotomus sergenti and Ph. tobbi (Diptera: Psychodidae)

Two new gregarines in the recently erected genus Psychodiella (formerly Ascogregarina), Psychodiella sergenti n. sp. and Psychodiella tobbi n. sp., are described based on morphology and life cycle observations conducted on larvae and adults of their natural hosts, the sand flies Phlebotomus sergenti and Phlebotomus tobbi, respectively. The phylogenetic analyses inferred from small subunit ribosomal DNA (SSU rDNA) sequences indicate the monophyly of newly described species with Psychodiella chagasi. Ps. sergenti n. sp. and Ps. tobbi n. sp. significantly differ from each other in the life cycle and in the size of life stages. The sexual development of Ps. sergenti n. sp. (syzygy, formation of gametocysts and oocysts) takes place exclusively in blood-fed Ph. sergenti females, while the sexual development of Ps. tobbi n. sp. takes place also in males and unfed females of Ph. tobbi. The susceptibility of Phlebotomus perniciosus, Phlebotomus papatasi, Ph. sergenti, Ph. tobbi, and Phlebotomus arabicus to both gregarines was examined by exposing 1st instar larvae to parasite oocysts. High host specificity was observed, as both gregarines were able to fully develop and complete regularly the life cycle only in their natural hosts. Both gregarines are considered as serious pathogens in laboratory-reared colonies of Old World sand flies.     

Nodulation in black locust by the Gammaproteobacteria Pseudomonas sp. and the Betaproteobacteria Burkholderia sp.

Nodulation abilities of bacteria in the subclasses Gammaproteobacteria and Betaproteobacteria on black locust (Robinia pseudoacacia) were tested. Pseudomonas sp., Burkholderia sp., Klebsiella sp., and Paenibacillus sp. were isolated from surface-sterilized black locust nodules, but their nodulation ability is unknown. The aims of this study were to determine if these bacteria are symbiotic. The species and genera of the strains were determined by RFLP analysis and DNA sequencing of 16S rRNA gene. Inoculation tests and histological studies revealed that Pseudomonas sp. and Burkholderia sp. formed nodules on black locust and also developed differentiated nodule tissue. Furthermore, a phylogenetic analysis of nodA and a BLASTN analysis of the nodC, nifH, and nifHD genes revealed that these symbiotic genes of Pseudomonas sp. and Burkholderia sp. have high similarities with those of rhizobial species, indicating that the strains acquired the symbiotic genes from rhizobial species in the soil. Therefore, in an actual rhizosphere, bacterial diversity of nodulating legumes may be broader than expected in the Alpha-, Beta-, and Gammaproteobacteria subclasses. The results indicate the importance of horizontal gene transfer for establishing symbiotic interactions in the rhizosphere.     

Achromobacter animicus sp. nov., Achromobacter mucicolens sp. nov., Achromobacter pulmonis sp. nov. and Achromobacter spiritinus sp. nov., from human clinical samples

The phenotypic and genotypic characteristics of fourteen human clinical Achromobacter strains representing four genogroups which were delineated by sequence analysis of nusA, eno, rpoB, gltB, lepA, nuoL and nrdA loci, demonstrated that they represent four novel Achromobacter species. The present study also characterized and provided two additional reference strains for Achromobacter ruhlandii and Achromobacter marplatensis, species for which, thus far, only single strains are publicly available, and further validated the use of 2.1% concatenated nusA, eno, rpoB, gltB, lepA, nuoL and nrdA sequence divergence as a threshold value for species delineation in this genus. Finally, although most Achromobacter species can be distinguished by biochemical characteristics, the present study also highlighted considerable phenotypic intraspecies variability and demonstrated that the type strains may be phenotypically poor representatives of the species. We propose to classify the fourteen human clinical strains as Achromobacter mucicolens sp. nov. (with strain LMG 26685^T [=CCUG 61961^T] as the type strain), Achromobacter animicus sp. nov. (with strain LMG 26690^T [=CCUG 61966^T] as the type strain), Achromobacter spiritinus sp. nov. (with strain LMG 26692^T [=CCUG 61968^T] as the type strain), and Achromobacter pulmonis sp. nov. (with strain LMG 26696^T [=CCUG 61972^T] as the type strain).     

Los géneros Praectenodonta, Praenucula y Notonucula (Palaeotaxodonta : Bivalvia) en el Siluro-Devónico de Bolivia

Taxonomy of 57 bivalves, internal and external molds is described in this paper, corresponding to three paleotaxodontids genera Praectenodonta, Praenucula and Notonucula. Samples were collected from nine sites, where stratigraphic columns were measured in Silurian to Devonian series from Altiplano, Cordillera Oriental and Interandean of Bolivia. For the first time in Bolivia, Praectenodonta and Notonucula have been identified. Four species have been described, three of them are new: Praectenodonta boliviensis n. sp., Praenucula quichua n. sp. and Notonucula altiplanica n. sp. Paleogeography of new species and genera is proposed.     

Allelopathic effects of the Baltic cyanobacteria Nodularia spumdigena, Aphanizomenon flos-aquae and Anabaena lemmermannii on algal monocultures

Allelopathy, the release of extracellular compounds that inhibit the growth of other microorganisms, may be one factor contributing to the formation and/or maintenance of cyanobacterial blooms. We investigated the allelopathic effects of three cyanobacterial species (Nodularia spumigena, Aphanizomenon flos-aquae and Anabaena lemmermannii) that frequently form mass-occurrences in the Baltic Sea. We exposed monocultures of three phytoplankton species (Thalassiosira weissflogii, Rhodomonas sp. and Prymnesium parvum) to cell-free filtrates of the three cyanobacteria, and quantified allelopathic effects with cell counts. We also investigated the role of the growth phase of cyanobacteria in their allelopathy, by comparing the effects of an exponential and a stationary phase culture of N. spumigena. All tested cyanobacteria inhibited the growth of Rhodomonas sp., but none of them affected P. parvum. The effects on T. weissflogii were more variable, and they were amplified by repeated filtrate additions compared to a single filtrate addition. N. spumigena was more allelopathic in exponential than in stationary growth phase, whereas the culture filtrate was more hepatotoxic in stationary phase. Hepatotoxins were thus probably not involved in the allelopathic effects, which is also indicated by the allelopathic properties of the non-toxic A. flos-aquae and A. lemmermannii. The results demonstrate that the common Baltic cyanobacteria affect some coexisting phytoplankton species negatively. Allelopathy may therefore play a role in interspecific competition and contribute to cyanobacterial bloom maintenance.     

Phytophthora species isolated from alpine and sub-alpine regions of Australia,including the description of two new species; Phytophthora cacuminis sp. nov and Phytophthora oreophila sp. nov

Plant deaths had been observed in the sub-alpine and alpine areas of Australia. Although no detailed aetiology was established, patches of dying vegetation and progressive thinning of canopy suggested the involvement of root pathogens. Baiting of roots and associated rhizosphere soil from surveys conducted in mountainous regions New South Wales and Tasmania resulted in the isolation of eight Phytophthora species; Phytophthora cactorum, Phytophthora cryptogea, Phytophthora fallax, Phytophthora gonapodyides, Phytophthora gregata, Phytophthora pseudocryptogea, and two new species, Phytophthora cacuminis sp. nov and Phytophthora oreophila sp. nov, described here. P. cacuminis sp. nov is closely related to P. fallax, and was isolated from asymptomatic Eucalyptus coccifera and species from the family Proteaceae in Mount Field NP in Tasmania. P. oreophila sp. nov, was isolated from a disturbed alpine herbfield in Kosciuzsko National Park. The low cardinal temperature for growth of the new species suggest they are well adapted to survive under these conditions, and should be regarded as potential threats to the diverse flora of sub-alpine/alpine ecosystems. P. gregata and P. cryptogea have already been implicated in poor plant health. Tests on a range of alpine/subalpine plant species are now needed to determine their pathogenicity, host range and invasive potential.     

Wild peanut Arachis duranensis are nodulated by diverse and novel Bradyrhizobium species in acid soils

Aiming at learning the microsymbionts of Arachis duranensis, a diploid ancestor of cultivated peanut, genetic and symbiotic characterization of 32 isolates from root nodules of this plant grown in its new habitat Guangzhou was performed. Based upon the phylogeny of 16S rRNA, atpD and recA genes, diverse bacteria belonging to Bradyrhizobium yuanmingense, Bradyrhizobium elkanii, Bradyrhizobium iriomotense and four new lineages of Bradyrhizobium (19 isolates), Rhizobium/Agrobacterium (9 isolates), Herbaspirillum (2 isolates) and Burkholderia (2 isolates) were defined. In the nodulation test on peanut, only the bradyrhizobial strains were able to induce effective nodules. Phylogeny of nodC divided the Bradyrhizobium isolates into four lineages corresponding to the grouping results in phylogenetic analysis of housekeeping genes, suggesting that this symbiosis gene was mainly maintained by vertical gene transfer. These results demonstrate that A. duranensis is a promiscuous host preferred the Bradyrhizobium species with different symbiotic gene background as microsymbionts, and that it might have selected some native rhizobia, especially the novel lineages Bradyrhizobium sp. I and sp. II, in its new habitat Guangzhou. These findings formed a basis for further study on adaptation and evolution of symbiosis between the introduced legumes and the indigenous rhizobia.     

A new wilt and die-back disease of Acacia mangium associated with Ceratocystis manginecans and C. acaciivora sp. nov. in Indonesia

Species of Ceratocystis are well-known wound related pathogens of many tree species, including commercially planted Acacia spp. Recently, several Ceratocystis isolates were collected from wilting A. mangium in plantations in Indonesia. The aim of this study was to identify these Ceratocystis isolates and to investigate their ability to cause disease on two plantation-grown Acacia spp. using greenhouse and field inoculation experiments. For identification, morphological characteristics and comparisons of DNA sequence data for the ITS, β-tubulin and TEF 1-α gene regions, was used. Ceratocystis isolates were identified as C. manginecans, a serious pathogen of mango trees in Oman and Pakistan and a previously undescribed species, described here as C. acaciivora sp. nov. Both fungi produced significant lesions in inoculation experiments on A. mangium and A. crassicarpa, however, C. acaciivora was most pathogenic suggesting that this fungus is the primary cause of the death of trees under natural conditions.     

Koralionastetales, a new order of marine Ascomycota in the Sordariomycetes

Based on molecular studies using 1760 bp of the nuSSU and 604 bp of the nuLSU rRNA genes and using morphological characters, the genera Koralionastes and Pontogeneia are assigned to the new order Koralionastetales, family Koralionastetaceae, class Sordariomycetes. Koralionastetales is a sister group to Lulworthiales; differences in morphological characters are expressed in the ascospores and the presence/absence of periphyses and paraphyses. A new species of Pontogeneia, P. microdictyi from Microdictyon sp. in the Bahamas, is described.     

Association of a luminous Vibrio sp., taxonomically related to Vibrio harveyi, with Clytia linearis (Thornely, 1900) (Hydrozoa, Cnidaria)

A previously unknown association between a luminous Vibrio sp., taxonomically related to the species Vibrio harveyi and a common member of the shallow/mid water communities of the Mediterranean Sea, the hydrozoan Clytia linearis is described. All the specimens of C. linearis observed under blue light excitation showed both a natural luminescence appearing as a series of fine dots due to clytin, and a clear fluorescence on the external side of the perisarc around the colonies due to the presence of luminous bacteria. Luminous bacteria were isolated from the surface of C. linearis, their phenotypic characterization as isolates was performed by several morphological, biochemical, and cultural tests, completed with 16S rDNA sequence analysis. All the isolates were referred to a Vibrio sp. taxonomically related to V. harveyi. The association of the V. harveyi-related species with C. linearis, as already suggested for another hydroid, Aglaophenia octodonta, could be explained with the activity of these bacteria of feeding on the chitinous structures present in these hydroids. Moreover, the adhesion of the luminous bacterium (here referred to as Vibrio sp. CL1) on C. linearis may contribute to the survival of this Vibrio species in the marine environment providing a suitable growth habitat.     

Proposal to assign Aeromonas diversa sp. nov. as a novel species designation for Aeromonas group 501

The Aeromonas group 501, also named Aeromonas sp. HG13, is taxonomically close to A. schubertii. Results obtained in previous studies, including DNA–DNA hybridization and DNA fingerprinting, suggest that Aeromonas group 501 could constitute a different Aeromonas species. In this work we have performed a polyphasic study with the two strains comprising the Aeromonas sp. HG13 in order to propose a formal species name. They could be differentiated from A. schubertii by the indole and lysine decarboxylase tests and the utilization of l-lactate. Phenotypically, both strains were also easily separated from the other Aeromonas species. Sequence analysis of the 16S rRNA gene showed high sequence similarities (>97%) between Aeromonas group 501 and all Aeromonas species. Nevertheless, sequence divergences of cpn60, dnaJ, gyrB and rpoD genes were higher than the intraspecific threshold values established for each gene (3.5%, 3.3%, 2.3% and 2.6%, respectively), while sequence divergences between strains CDC 2478-85^T and CDC 2555-87 were low (0.6–1.1%). The DNA G+C content of the type strain was 62.2 mol%. Phenotypic and genotypic evidence strongly suggests that the Aeromonas group 501 is a novel species of the genus Aeromonas, for which the name Aeromonas diversa sp. nov. is proposed. The type strain is CDC 2478-85^T (=CECT 4254^T=ATCC 43946^T=LMG 17321^T).     

Natural products as sources of new fungicides (V): Design and synthesis of acetophenone derivatives against phytopathogenic fungi in vitro and in vivo

A series of acetophenone derivatives (10a–10i, 11, 12a–12g, 13a–13g, 14a–14d and 15a–15l) were designed, synthesized and evaluated for antifungal activities in vitro and in vivo. The antifungal activities of 53 compounds were tested against several plant pathogens, and their structure–activity relationship was summarized. Compounds 10a–10f displayed better antifungal effects than two reference fungicides. Interestingly, the most potent compound 10d exhibited antifungal properties against Cytospora sp., Botrytis cinerea, Magnaporthe grisea, with IC₅₀ values of 6.0–22.6?µg/mL, especially Cytospora sp. (IC₅₀?=?6.0?µg/mL). In the in vivo antifungal assays, 10d displayed the significant protective efficacy of 55.3% to Botrytis cinerea and 73.1% to Cytospora sp. The findings indicated that 10d may act as a potential pesticide lead compound that merits further investigation.     

Metabolism of the phytoalexins medicarpin and maackiain by Fusarium solani

Non-inhibitory concentrations of the pterocarpan phytoalexin medicarpin were completely metabolized by isolates of Fusarium solani f. sp. pisi, f. sp. cucurbitae, f. sp. phaseoli and two other F. solani isolates genetically related to f. sp. pisi during 24 hr of growth in liquid medium. The major metabolic products accumulated without significant further degradation. Medicarpin was modified at one of three adjacent carbon atoms to form either an isoflavanone derivative, a 1a-hydroxydienone derivative or 6a-hydroxymedicarpin. Whereas each isolate degraded medicarpin to one or more metabolises, the isolates varied as to which metabolise they produced. Maackiain, another pterocarpan phytoalexin, was also metabolized by all the isolates to products analogous to those formed from medicarpin. The ability to metabolize medicarpin and maackiain was not always associated with the ability to metabolize pisatin and phaseollin, two other pterocarpan phytoalexins that were degraded by several of the isolates. Tolerance of medicarpin and maackiain was similarly not always associated with tolerance to pisatin.     

Hematodinium sp. infection of red Paralithodes camtschaticus and blue Paralithodes platypus king crabs from the Sea of Okhotsk, Russia

A disease caused by a parasitic dinoflagellate of the genus Hematodinium was identified in red, Paralithodes camtschaticus, and blue, Paralithodes platypus, king crabs from the north-east region of the Sea of Okhotsk, Russia, during annual stock surveys. No carapace color change was observed even in heavily infected crabs, but diseased crabs possessed creamy-yellow hemolymph, which was visible through the arthrodial membranes of the abdomen and appendages. Several stages of the parasite’s life history, including trophonts, plasmodia, sporonts and macrodinospores, were observed in tissues of infected king crabs. Numerous parasite cells were observed in the lumina of the myocardium, the gills, the connective tissue of antennal glands and the sinuses of nerve ganglia, eyestalks and gastrointestinal tract of king crabs with gross signs of infection. Based on sequencing of the 18S rDNA, it appears that the Hematodinium sp. found in red and blue king crabs is identical or closely related to Hematodinium sp. isolated from crabs of the genera Chionoecetes and Lithodes. Observed prevalences were 0.33% in sublegal male red king crabs, 0.18% in female red king crabs, 0.34% in sublegal male blue king crabs and 0.31% in female blue king crabs.     

Genomic insight into the taxonomy of Rhizobium genospecies that nodulate Phaseolus vulgaris

Due to the wide cultivation of bean (Phaseolus vulgaris L.), rhizobia associated with this plant have been isolated from many different geographical regions. In order to investigate the species diversity of bean rhizobia, comparative genome sequence analysis was performed in the present study for 69 Rhizobium strains mainly isolated from root nodules of bean and clover (Trifolium spp.). Based on genome average nucleotide identity, digital DNA:DNA hybridization, and phylogenetic analysis of 1,458 single-copy core genes, these strains were classified into 28 clusters, consistent with their species definition based on multilocus sequence analysis (MLSA) of atpD, glnII, and recA. The bean rhizobia were found in 16 defined species and nine putative novel species; in addition, 35 strains previously described as Rhizobium etli, Rhizobium phaseoli, Rhizobium vallis, Rhizobium gallicum, Rhizobium leguminosarum and Rhizobium spp. should be renamed. The phylogenetic patterns of symbiotic genes nodC and nifH were highly host-specific and inconsistent with the genomic phylogeny. Multiple symbiovars (sv.) within the Rhizobium species were found as a common feature: sv. phaseoli, sv. trifolii and sv. viciae in Rhizobium anhuiense; sv. phaseoli and sv. mimosae in Rhizobium sophoriradicis/R. etli/Rhizobium sp. III; sv. phaseoli and sv. trifolii in Rhizobium hidalgonense/Rhizobium acidisoli; sv. phaseoli and sv. viciae in R. leguminosarum/Rhizobium sp. IX; sv. trifolii and sv. viciae in Rhizobium laguerreae. Thus, genomic comparison revealed great species diversity in bean rhizobia, corrected the species definition of some previously misnamed strains, and demonstrated the MLSA a valuable and simple method for defining Rhizobium species.     

Neoaplectana species: Specificity of association with bacteria of the genus Xenorhabdus

Each of five Neoaplectana (Nematoda: Steinernematidae) species was cultured monoxenically with various Xenorhabdus (Eubacteriales: Enterobacteriaceae) isolates. The nematodes were usually able to reproduce when cultured with the bacterial symbiont of any one of the five Neoaplectana spp. but never with Xenorhabdus luminescens, symbiotic with Heterorhabditis spp., or with the Xenorhabdus sp. isolated from an undescribed steinernematid species. Only Neoaplectana bibionis could be cultured with the Xenorhabdus symbiont of Steinernema kraussei. A high proportion of infectives were able to carry within their intestine X. nematophilus isolated from other strains of the same nematode species; a small proportion of infectives were able to carry X. nematophilus isolated from other nematode species.     

Growth of Stigeoclonium and Oedogonium species in artificial ammonium-N and phosphate-P gradients

Four benthic filamentous Chlorophycean species (three Stigeoclonium species and one Oedogonium species) were obtained from two ditches, influenced, respectively, by the point discharges of pig farm and sewage treatment plant effluents. The ditches showed a gradual change in water chemistry, particularly with regard to ammonium-N and phosphate-P. The growth of the algae was studied in artificial ammonium-N (concentration range of 1–100 mg l^?1) and phosphate-P gradients (concentration range of 0.1–15 mg l^?1), which were based on concentrations of these nutrients in the ditches. Maximum growth in ammonium-N was attained for S. aestivale Hazen Z1 and S helveticum Vischer P4 at 50 mg l^?1, for S. aestivale Z4 and Oedogonium sp. Z4 at 10 mg l^?1, and for S. amoenum Kützing P2 at 5 mg l^?1. Maximum growth in phosphate-P was attained for S. helveticum P4 at 15 mg l^?1, for S. aestivale Z1 and S. amoenum P2 at 1.5 mg l^?1, and for S. aestivale Z4 and Oedogonium sp. Z4 at 1 mg l^?1.It is concluded that the ammonium-N and phosphate-P levels of ditches determined the distribution of the algae along the ditches, and therefore influenced the species composition of the periphyton communities.The study revealed a population differentiation with regard to ammonium-N in two closely adjacent populations of S. aestivale.