Light and Electron Microscope Study of Urosporidium cannoni N. Sp., a Haplosporidian Parasite of the Polyclad Turbellarian Stylochus sp.

ABSTRACT. Urosporidium cannoni n. sp. was found in most tissues of a polyclad turbellarian associated with commercial oyster farms from eastern Moreton Bay, Australia. Mature spores had 11 to 13 episporal tails at irregular intervals around the spore wall. The spherule, prominent in development, dispersed as the spores matured. Spores were found within cysts that contained up to a few hundred spores at the same stage of development. Mature cysts occurred in groups and their masses of dark, golden spores resulted in black patches on the otherwise red-brown turbellarian. The infection may have commercial importance.     

Testicular myxosporidiasis in the flat-backed toad, Bufo maculatus (Amphibia: Bufonidae), from Cameroon, Africa.

Macroscopic cysts measuring less than or equal to 860 x 500 microns were found in the testes of a flat-backed toad, Bufo maculatus, collected in Cameroon, West Africa. On histologic examination, the cysts contained numerous spores of a Myxobolus sp. (Myxozoa: Myxobolidae). Spores in fixed tissues measured 9.2 microns long, 8.9 microns wide, and 4.0 microns thick; the range of values for length, width, and thickness were 8.8 to 9.6 microns, 8.6 to 9.4 microns, 3.6 to 4.4 microns, respectively (n = 20). The shape index (length/width) was 1.03, and ranged from 1.00 to 1.09. Pathology was limited to a slight constriction of adjacent seminiferous tubules by the cysts. No host inflammatory response was noted. This myxozoan is distinct from all other members of the genus infecting anurans and is assigned the name Myxobolus bufonis sp. n.     

A new microsporidium from the oyster Ostrea lutaria in New Zealand

Microsporidium rapuae n. sp. (Microsporida) forms cysts within the connective tissue surrounding the gut epithelium of the oyster Ostrea lutaria. Except for encapsulation of the cysts by fibroblasts no pathogenic effects were observed. Each cyst contained a large number of spores possessing long well-developed polar filaments. This is the third Microspora recorded from Bivalvia (Mollusca), and the first which does not belong to the family Chytridiopsidae (Minisporida).     

Pseudomonocystis sp., an Eugregarine Protozoan Pathogen of the Coconut Root Grub, Leucopholis coneophora

Populations of the coconut root grub , Leucopholis coneophora, were infected by an eugre garine protozoan pathogen , Pseudomonocystis sp . The pathogen infected 22.7% third - instar L. coneophora larvae in the field . The infected larvae produced 1 - 84 (average 37 . 11) milky - white , membranous , elliptical cysts measuring 2 . 64 1 . 24 mm . Each cyst contained about 3 . 80 105 mucilaginous spores . The spores were elliptical with two tubular polar caps , thick - walled , ornamented with irregular ridges and furrows , and measured 26 . 04 13 . 61 mum . The LD and LT for oral inoculation of spores into third - instar larvae were 9 . 86 104 50 50 spores / larva and 27 . 62 days respectively . Ingestion of spores with or without food and connibalism of infected larvae were the modes of transmission of the pathogen .     

Fungal Parasites of the Cereal Cyst Nematode Heterodera avenae in Southern Sweden

Fungal parasites of the cereal cyst nematode Heterodera avenae were isolated from four sites in southern Sweden. In all, 15 different fungi were isolated from different stages of the nematode life cycle. Among the egg parasites, Verticillium chlamydosporium was common in young cysts on roots, whereas an unidentified species of Verticillium (Verticillium sp. 1) was the dominating species in cysts from soil, especially if the soll had been stored for 8-12 months. V. chlamydosporium was frequently isolated from eggs in cysts from soil, when analyzed shortly after sampling. Verticillium sp. 1 is distinct from V. chlamydosporium because it does not produce dichtyo-chlamydospores in the aerial mycelium and because it grows at 6 C where V. chlamydosporium fails to grow. Paecilomyces lilacinus, Microdochium bolleyi, Cylindrocarpon sp., and several nonsporulating fungi were also isolated from eggs in cysts from soil. Between 10 and 20% of the eggs in cysts collected in the field were infected with fungi. In a pot test between < 1 and 29%, with a mean of 13%, of females on roots became infected, always by Nematophthora gynophila. Resting spores of N. gynophila extracted directly from field soil, collected at the four sites, varied from 3 to 49 spores/gram of air dried soil.     

Unicapsula marquesi n. sp. (Mysxosporea, Multivalvulida) a gill parasite of Polydactylus quadrifilis (Cuvier, 1829) (Pisces, Polynemidae) from the senegalese coast (West Africa)]

Unicapsula marquesi n. sp. (Myxosporea) is described from gill filaments of Polydactylus quadrifilis (Pisces, Polynemidae) obtained from coats of Senegal. The cysts were elongated and their length was 1 to 3 mm. The spores were pyramidal and composed of three valves. Only one of theses valves contained a developed polar capsule measuring 3.01 +/- 0.09 microns in diameter. Length of spore was 6.13 +/- 0.21 microns and the width was 7.18 +/- 0.17. No filament like appendage at the extremity of shell valves. Data on ultrastructure of spores are presented.     

Morphological and molecular comparison of <Emphasis Type="Italic">Myxobolus procerus</Emphasis> (Kudo, 1934) and <Emphasis Type="Italic">M. intramusculi</Emphasis> n. sp. (Myxozoa) parasitising muscles of the trout-perch <Emphasis Type="Italic">Percopsis omiscomaycus</Emphasis>

Inter- and intracellular cysts from a presumed single species, Myxobolus procerus (Kudo, 1934), parasitising the trout-perch Percopsis omiscomaycus were compared with respect to their spore morphology and small subunit 18S ribosomal DNA. The two cyst types have similar pyriform spores and comparable ranges in spore length and width, size of the polar capsules and number of filament coils. However, fixed spores of the intracellular cysts are significantly shorter (p < 0.05) in mean length than those from intercellular cysts, giving them a broader appearance. Comparing 991 base pairs of 18S rDNA revealed a 20 bp difference between the two cyst types (97.9% similarity), 10 due to base substitutions and 10 due to the presence or absence of a base. The described morphological differences and consistent 2.1% difference in the 18S rDNA reveal that the intracellular form is a separate species, which is described herein as Myxobolus intramusculi n. sp. M. intramusculi n. sp. and M. procerus may be sister species and it is suggested that the two species arose through sympatric speciation involving a switch in site specificity within a single host species.     

Resting stages of microalgae in recent marine sediments of Peter the Great Bay,Sea of Japan

Data on the qualitative and quantitative composition of resting stages of planktonic microalgae in recent marine sediments of Peter the Great Bay (Sea of Japan) over the period 2000–2007 are presented. A total of sixty one morphological forms of resting stages represented by dinoflagellate and raphidophyte cysts and diatom spores and resting cells were recorded in the sediment samples. This study revealed cysts of the potentially toxic species Alexandrium tamarense, A. cf. minutum, Alexandrium sp., Gymnodinium catenatum (PSP toxin producers), and Protoceratium reticulatum (yessotoxin producer); resting cells of Pseudo-nitzschia sp. (potential producer of domoic acid); and cysts of bloom-forming species Cochlodinium cf. polykrikoides and Heterosigma cf. akashiwo.     

Parasites and pathologic conditions of the cockle Cerastoderma edule populations of the coast of Galicia (NW Spain).

A survey of pathological conditions affecting cockle populations of the most economically important natural beds of Galician estuaries in NW Spain was performed. Samples of 30 adult cockles were collected from each of 34 natural beds in the spring of 1999 and processed by histological techniques. Disseminated neoplasia were seen in samples from most of the natural beds, in some cases with a high prevalence. The gregarine Nematopsis sp., larval trematode stages, and branchial extracellular large cysts enclosing bacteria-like microorganisms were the most prevalent parasites. Paravortex cardii, intracellular colonies of rickettsiae-like organisms in digestive and gill epithelium, Pseudoklossia sp. coccidians, Trichodina sp., and other ciliates were frequently seen in the samples. Copepods in gills and intestine and unidentified gregarines in intestine epithelia and surrounding connective tissue were less prevalent and were observed in samples of some natural beds. Large foci of heavy hemocytic infiltration were detected in a few sites only. Cysts of Steinhausia sp. and plasmodia and spores of a haplosporidian were seen in cockles from two localities. Inflammation was frequently observed in the samples. Some of the parasites and pathological conditions could be associated with mortality.     

Polen y esporas de la Formación La Irene (Maastrichtiano), sudoeste de la provincia de Santa Cruz, Argentina: primeros resultados

Palynological assemblages are reported for the first time for the La Irene Formation, southwestern Santa Cruz Province, Argentina. This unit represents the sedimentation during a regressive period from transitional or delta-plain to fluvial environments. Palynological assemblages are scarce and moderately well preserved. They mainly consist of continental elements (wood remains, cuticles, spores and pollen grains) with scarse marine palynomorphs (dinoflagellate cysts). The spore-pollen assemblages are dominated by fern spores, followed by angiosperm and gymnosperm pollen grains. Bryophyte spores and fungal remains are also present. Among ferns, Cyatheaceae and spores of Laevigatosporites, of uncertain affinity, are dominant. Of the angiosperm pollen, those of Chloranthaceae (Clavatipollenites sp.) and Arecaceae (Arecipites spp., Longapertites sp., Spinizonocolpites hialinus Archangelsky and Zamaloa) are the most abundant. Pollen of Liliaceae (Liliacidites spp.), Proteaceae (Proteacidites sp., Peninsulapollis gillii (Cookson) Dettmann and Jarzen, Retidiporites camachoii Archangelsky) and Ericaceae (Ericipites scabratus Harris) are also present. Gymnosperm pollen is represented by Podocarpaceae (Podocarpidites spp.) and Ephedraceae (Equisetosporites sp.). These palynological suites would represent a fern-angiosperm dominated coastal vegetation, developed under warm and at least locally humid climatic conditions. La Irene Formation is considered Maastrichtian in age based on stratigraphic evidence, which is, in turn consistent with the ages suggested by the species ranges and the similarities observed with others previously described assemblages. This is the southernmost record of Spinizonocolpites, similar to the extant mangrove palm Nypa.     

A new species of Myxozoa, Henneguya rondoni n. sp. (Myxozoa), from the peripheral nervous system of the Amazonian fish, Gymnorhamphichthys rondoni (Teleostei)

Henneguya rondoni n. sp. found in the peripheral lateral nerves located below the two lateral lines of the fish Gymnorhamphichthys rondoni (Teleostei, Rhamphichthyidae) from the Amazon river is described using light and electron microscopy. Spherical to ellipsoid cysts measuring up to 110 microm in length contained only immature and mature spores located in close contact with the myelin sheaths of the nervous fibres. Ellipsoidal spores measured 17.7 (16.9-18.1)-microm long, 3.6 (3.0-3.9)-microm wide, and 2.5 (2.2-2.8)-microm (n=25) thick. The spore body measuring 7.0 (6.8-7.3)-microm long was formed by two equal symmetric valves, each with an equal tapering tail 10.7 (10.3-11.0) microm in length. The tails were composed of an internal dense material surrounded by an external homogeneous sheath of hyaline substance. The valves surrounded two equal pyriform polar capsules measuring 2.5 (2.2-2.8)-microm long and 0.85 (0.79-0.88)-microm (n=25) wide and a binucleated sporoplasm cell containing globular sporoplasmosomes 0.38 (0.33-0.42) microm (n=25) in diam. with an internal eccentric dense structure with half-crescent section. Each polar capsule contains an anisofilar polar filament with 6-7 turns obliquely to the long axis. The matrix of the polar capsule was dense and the wall filled with a hyaline substance. The spores differed from those of previously described species. Based on the ultrastructural morphology of the spore and specificity to the host species, we propose a new species name H. rondoni n. sp.     

The nature of Thelohania solenopsae (Microsporidia) cysts in abdomens of red imported fire ants, Solenopsis invicta

Sixty four percent of Solenopsis invicta workers infected with Thelohania solenopsis contained 1-6 "cysts" ranging from 70 to 260 microm in diameter. Light and electron microscope analyses showed that cysts are hypertrophied adipocytes transformed by the parasites, each cyst presumably forming from a single cell. In the first step of the pathogenesis, Nosema-like spores functioning in autoinfection are produced; a diplokaryotic sequence leading to their formation causes fat body hypertrophy. When meiosis occurs, it switches parasite development to production of octospores and/or megaspores. Adipocytes become 2-4xlarger than normal in conjunction with intensive parasite multiplication and octospore maturation. Infected cells eventually lose their cellular organization and are converted into reservoirs for spores. There were no manifestations of cellular immunity, such as encapsulation or nodule formation. Similarly, there were no signs of specialized host-parasite interaction that might be interpreted as xenoma-like complexes. The role of the cysts in the parasite's life cycle is unclear. They may represent a defensive reaction of the host sacrificing the infected cells to segregate the infection. Alternatively, the cyst may help protect spores from environmental hazards and provide a concentrated infectious dose to aid horizontal transmission of the microsporidium. We propose to refer to hypertrophied adipocytes filled with T. solenospsae spores as "sporocytosacs", not "cysts."     

UV inactivation of pathogenic and indicator microorganisms

Survival was measured as a function of the dose of germicidal UV light for the bacteria Escherichia coli, Salmonella typhi, Shigella sonnei, Streptococcus faecalis, Staphylococcus aureus, and Bacillus subtilis spores, the enteric viruses poliovirus type 1 and simian rotavirus SA11, the cysts of the protozoan Acanthamoeba castellanii, as well as for total coliforms and standard plate count microorganisms from secondary effluent. The doses of UV light necessary for a 99.9% inactivation of the cultured vegetative bacteria, total coliforms, and standard plate count microorganisms were comparable. However, the viruses, the bacterial spores, and the amoebic cysts required about 3 to 4 times, 9 times, and 15 times, respectively, the dose required for E. coli. These ratios covered a narrower relative dose range than that previously reported for chlorine disinfection of E. coli, viruses, spores, and cysts.     

UV inactivation of pathogenic and indicator microorganisms.

Survival was measured as a function of the dose of germicidal UV light for the bacteria Escherichia coli, Salmonella typhi, Shigella sonnei, Streptococcus faecalis, Staphylococcus aureus, and Bacillus subtilis spores, the enteric viruses poliovirus type 1 and simian rotavirus SA11, the cysts of the protozoan Acanthamoeba castellanii, as well as for total coliforms and standard plate count microorganisms from secondary effluent. The doses of UV light necessary for a 99.9% inactivation of the cultured vegetative bacteria, total coliforms, and standard plate count microorganisms were comparable. However, the viruses, the bacterial spores, and the amoebic cysts required about 3 to 4 times, 9 times, and 15 times, respectively, the dose required for E. coli. These ratios covered a narrower relative dose range than that previously reported for chlorine disinfection of E. coli, viruses, spores, and cysts.     

Gill infection of Leporinus macrocephalus Garavello & Britski, 1988 (Osteichthyes: Anostomidae) by Henneguya leporinicola n. sp. (Myxozoa: Myxobolidae). Description, histopathology and treatment

Piau?us (Leporinus macrocephalus), were raised in 300 m2 ponds (density of 10 fish/m2) presenting asphyxia signals and daily mortality of 27 fishes. Specimens with 8-cm total body length, were collected for necropsy. Mucus of body surface and pieces of organs were collected and examined microscopically, in wet mounts, stained or in histological sections. The smears examination showed the presence of several spores in the secondary lamellae of the gill filaments, identified as Henneguya leporinicola n.sp (Myxozoa: Myxobolidae). Histopathological study showed epithelial hyperplasia and fulfilling of the spaces between the secondary lamellae, congestion and telangiectasia sinusoidal. It was also observed hyperplasia of the goblet cells and several cysts of parasite with 70.3 microns diameter. Such cysts were situated among the secondary lamellae, covered or not by the hyperplasic epithelium. With this diagnostic, three applications of formalin solution 10 ml/m3 were carried out. Fifteen days after that, fish were examined again to ascertain whether the treatment was efficient on disease caused by the protozoa. The tissue alterations present in the gills after the treatment were just a moderate sinusoidal congestion and a slight epithelial hyperplasia on the base of the secondary lamellae.     

Lunnomidinium scaniense Lindström, gen. et sp. nov., a new suessiacean dinoflagellate cyst from the Rhaetian of Scania, southern Sweden

The dinoflagellate cyst Lunnomidinium scaniense gen. et sp. nov. is present in the lower part of a thin sequence of Rhaetian sedimentary rocks exposed in the Lunnom Coal and Clay Pit in NW Scania, southern Sweden. It occurs in diverse, Rhaetian palynomorph assemblages, dominated by spores and pollen, but with rare specimens of the dinoflagellate cysts Rhaetogonyaulax rhaetica (Sarjeant) Loeblich and Loeblich 1968, Shublikodinium sp. and Beaumontella? caminuspina (Wall) Below 1987. Lunnomidinium scaniense is characterized by an epicystal {tAtItP} archeopyle, a large number of paraplates arranged in seven or eight latitudinal series, and intratabular ornamentation in some but not all of the paraplate series. Thus, L. scaniense is assignable to the family Suessiaceae. Lunnomidinium scaniense can be subdivided into two different morphological varieties, based on the autophragm ornamentation and cyst size.     

Fine structure of the myxosporean,Henneguya curimata n. sp., parasite of the Amazonian fish,Curimata inormata (Teleostei,Curimatidae)

Henneguya curimata n. sp. (Myxozoa, Myxobolidae) is described from the kidney of the teleost Curimata inormata collected in an estuarine region of the Amazon River, near Belém. Brazil. This myxosporean produces large cysts (0.6-1.2 mm in diam.) that represent plasmodia containing all life cycle stages, including spores. The spore body is ellipsoidal (approximately 16.6 microm in length and approximately 6.2 microm in width), and each valve presents a tapering tail (approximately 19.1 microm in length). These valves surround the binucleate sporoplasm cell and two ellipsoidal polar capsules located side-by-side at the same level, measuring 6.5 x 1.2 microm each and containing 10-11 coils of the polar filament. On the basis of its host specificity and on data collected by light and electron microscopy, the organism, H. curimata n. sp. is distinguished as a new species. The taxonomic affinities and morphological comparisons with other similar species of the same genus are discussed.     

A Light Microscopic Comparison of The Cysts of Four Species of Sarcocystis Infecting The Domestic Reindeer (Rangifer Tarandus) in Northern Norway

Fresh preparations of micro-isolated sarcocysts from skeletal and cardiac muscle of 12 reindeer were examined by light microscopy. On the basis of cyst structure and cyst wall structure 4 Sarcocystis spp. could be differentiated. New names have been proposed for 2 previously unnamed Sarcocystis spp. of reindeer, and S. grueneri has been redefined. S. rangiferi n. sp. had macroscopic cysts in skeletal muscle measuring 2106×403 µm. The cyst wall protrusions were finger-like and measured 13.2×6.7 µm. The cysts were surrounded by a layer of fibrillar material. S. tarandi n. sp. had micro- to macroscopic cysts primarily in skeletal muscle, but a few cysts were found in the heart of one animal. In skeletal muscle the cysts measured 999×75µm; in the heart the cysts were shorter and wider. The cyst wall protrusions were fingerlike and measured 9.2×2.2 µm. S. grueneri had micro- to macroscopic cysts in cardiac muscle measuring 581×137 µm. The cyst wall was thin and relatively smooth with no visible protrusions. Sarcocystis sp. had micro- to macroscopic, slender cysts in skeletal muscle measuring 916×64 µm. The cyst wall had tightly packed, short, knob-like protrusions. The cysts of this species were previously classified as cysts of S. grueneri.     

Nosema muris n. sp., a New Microsporidian Parasite of the White Mouse (Mus musculus L.)

SYNOPSIS. A microsporidian, Nosema muris n. sp., is described from laboratory white mice in Czechoslovakia. I t differs from Nosema cuniculi (Levaditi, Nicolau and Schoen, 1923) and other Microsporidia in mice in that it develops in the omentum and heart muscle, iorming large masses of schizonts and spores. The parasite is distributed to other tissues (liver, spleen, fat, peritoneal muscles, connective tissue and brain) by infected mononudear cells, and then forms localized cysts in them. Kidney, lungs, adrenal glands, pancreas and salivary glands are not infected. The parasite can be transmitted via the placenta, by feeding on infected tissues, or by experimental injection of ascitic fluid.     

卷枝毛霉孢子原生质体的制备与再生

为了构建高产γ-亚麻酸的卷枝毛霉稳定遗传转化体系,利用酶解法对卷枝毛霉(Mucor circinelloides sp.)EIM-10的孢子进行原生质体制备。研究酶液组成、渗透压稳定剂、酶解温度、酶解时间等对卷枝毛霉孢子原生质体形成和再生的影响,建立了制备卷枝毛霉孢子原生质体的最适条件:1%纤维素酶和2%溶壁酶为酶解体系,0.5mol/L NaCl作为渗透压稳定剂,酶解温度32℃,酶解时间2.5 h,再生培养基为0.5 mol/L NaCl高渗培养基。用双层平板培养法进行原生质体再生,在此条件下原生质体的形成量为1.2×106个/mL,再生率为70.5%。