bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrastructural Study and Description of Ovavesicula popilliae N. G., N. Sp. (Microsporida: Pleistophoridae) from the Japanese Beetle, Popillia japonica (Coleoptera: Scarabaeidae)1
Authors: ANDREADIS THEODORE G. , HANULA JAMES L.
Published: May 2007

A new genus and species of microsporidia, Ovavesicula popilliae n. g., n. sp., is described from the Japanese beetle, Popillia japonica, on the basis of studies by light and electron microscopy. Parasite development primarily occurs within the Malpighian tubules of larvae, and spores are formed in a sporophorous vesicle. Meronts have diplokaryotic nuclei, develop in direct contact with the host cell cytoplasm, and divide by binary fission. Sporonts have unpaired nuclei, develop within a thick sporophorous vesicle, and undergo synchronous nuclear divisions producing plasmodia with 2, 4, 8, 16, and 32 nuclei. Cytokinesis of sporogonial plasmodia does not occur until karyokinesis is complete with 32 nuclei. Intact sporophorous vesicles are ovoid, containing numerous secretory products, and are surrounded by a persistent two‐layered wall. The uninucleate spores are regularly formed in groups of 32, and the polar tube in each has six coils.
In Vitro Excystation of Cryptosporidium baileyi from Chickens1
Authors: SUNDERMANN CHRISTINE A. , LINDSAY DAVID S. , BLAGBURN BYRON L.
Published: May 2007

Release of sporozoites from the oocysts of Cryptosporidium baileyi is described from Nomarski interference‐contrast microscopy. Just prior to excystation, the four sporozoites became motile and rearranged themselves within the oocyst. The sporozoites were then rapidly expelled through an opening that formed in the oocyst wall, and the residuum was either released or retained within the oocyst. Excysted sporozoites were crescent shaped and measured 5.0–9.0 μm × 1.0–1.6 μm (x̄= 6.8 × 1.1 μm). Excystation occurred when sodium taurocholate or a mixture of trypsin and sodium taurocholate was present in the incubation medium. High levels of excystation occurred at 37° or 40°C, but excystation did not occur at 4°C. The ability of biles from two avian and two mammalian hosts to produce excystation of C. baileyi was also studied. After a 2‐h incubation at 40°C, the percentages of excystation were 69.5% in goat bile, 45.0% in pig bile, 33.0% in chicken bile, and 34.5% in turkey bile.
Trypanosoma vivax: Adaptation of Two East African Stocks to Laboratory Rodents1
Authors: GATHUO H. K. W. , NANTULYA V. M. , GARDINER P. R.
Published: May 2007

Two Trypanosoma vivax stocks from East Africa have been adapted to rats and mice. Adaptation was induced by rapid passage at two‐ to four‐day intervals in sublethally irradiated rats. After 200 such passages, the two stocks gave rise to parasitemias of 109–1010 trypanosomes/ml in peripheral blood, and the infection was fatal in 90% of the rats. By passaging the rat‐adapted T. vivax into normal mice at two‐ to three‐day intervals for over 200 passages, the two stocks also became pathogenic to mice. One of the stocks was also capable of maintenance in non‐irradiated rats. The two stocks displayed a marked degree of pleomorphism in irradiated and non‐irradiated rats and mice. In the early rising parasitemia, the organisms were predominantly short, with a well formed undulating membrane, a pointed posterior end, and a large terminal kinetoplast. As parasitemia approached its peak, the organisms transformed into long, slender forms with an inconspicuous undulating membrane, an elongated posterior end, and a sub‐terminal kinetoplast. The short forms associated with the early, rising parasitemia were more infective for mice than the long forms encountered at peak parasitemia. Although the two rodent‐adapted stocks retained their pathogenicity for goats, neither the original stocks nor their corresponding rodent‐adapted stocks could be cyclically transmitted by tsetse flies. The availability of these stocks will greatly facilitate investigations on East African T. vivax which would otherwise be difficult to carry out in experimental rodents.
A Redescription of the Life Cycle of Eimeria mitis Tyzzer, 1929
Authors: NOVILLA M. N. , JEFFERS T. K. , GRIFFING W. J. , WHITE S. L.
Published: May 2007

Ten‐day‐old broiler chickens were inoculated with oocysts of a characterized strain of Eimeria mitis, and tissues were fixed at 4, 8, or 24‐h intervals after inoculation for histopathological examination. Tissue collections were initiated at the time of inoculation and extended up to 168 h postinoculation. The preferred site of development of E. mitis was found to be the ileum although more limited development of the parasite also took in the jejunum, cecal pouches, cloaca, and bursa of Fabricius. No distinctive and consistent intestinal lesions were macroscopically evident even in heavily parasitized chickens. The prepatent period was approximately 92 h postinoculation. The histopathological features of the E. mitis infections were characterized using conventional bright‐field microscopy as well as both scanning and transmission electron microscopy. No extra‐intestinal development of the parasite was observed.
In Vitro Reversible Transformation of Leishmania braziliensis panamensis Between Promastigote and Ellipsoidal Forms1
Authors: DARLING T. N. , BLUM J. J.
Published: May 2007

Raising the temperature of a log‐phase culture of Leishmania braziliensis panamensis promastigotes from 26°C to 34°C resulted in formation of a culture containing 85% ellipsoidally shaped forms after 1.5 h. The temperature‐induced ellipsoidal forms decreased in size but persisted in high proportion (85–95%) for at least 12 h at 34°C. Recovery from the ellipsoidal forms to a culture containing 85–95% promastigotes was observed after returning the temperature to 26°C. The time required for recovery increased markedly with the duration of the preceding heat treatment, up to about 70 h for a 12‐h heat treatment.
Observations on the Caudal Cilium of the Tomite of Ichthyophthirius multifiliis Fouquet, 18761,2
Authors: GEISSLINGER MARK
Published: May 2007

Light microscopy of live or silver‐impregnated specimens of the fish parasite Ichthyophthirius multifiliis show that the tomites are elongated and claviform with the anterior end broad. The cytostome, indicated by the presence of the organelle of Lieberkühn, is found in the lower part of the broadened anterior third of the tomite. The tapered posterior end bears a rigid, caudal cilium at its pole. Scanning electron microscopy reveals the caudal cilium and associated structures, including the depression from which the cilium protrudes, circumciliary ring, and raised struts on the ring. From these observations it is concluded that a previously reported “apical filament” found on the tomite is actually the posterior caudal cilium described by Canella & Rocchi‐Canella in 1976.
Cytoskeleton of Toxoplasma gondii1
Authors: NICHOLS BARBARA A. , CHIAPPINO MARY LOUISE
Published: May 2007

The cytoskeleton of Toxoplasma gondii was studied by electron microscopy using 1) whole mounts of detergent‐extracted parasites and 2) thin sections of routine preparations, tannic acid‐stained organisms, and detergent‐extracted parasites. In whole mounts, the spiral arrangement of the 22 pellicular microtubules closely corresponded to the pattern of surface ridges seen previously by scanning electron microscopy and reflected the torsion of the parasite body during locomotion. The microtubules had free posterior ends and were anchored anteriorly in the polar ring, presumed to be a microtubule organizing center (MTOC). The insertions of the microtubules were supported by blunt projections of the polar ring, forming a cogwheel pattern in transverse view. The internal microtubules had 13 protofilaments and were twice the length of the conoid. They extended through the conoid and ended at the anterior preconoidal ring, presumably a second MTOC. The subunits of the conoid were arranged in a counterclockwise spiral when traced from base to tip, as were the pellicular microtubules. We postulate that as the conoid moves, the polar ring complex moves along the spiral pathway of the conoid subunits. Retraction of the conoid would then rotate the polar ring, producing the torsion of the body we observed by SEM.
Mating Types in Aspidisca sp. (Ciliophora, Hypotrichida): a Cluster of Cryptic Species
Authors: DINI FERNANDO , BRACCHI PAOLO , GIANNÍ ALESSANDRO
Published: May 2007

A mating‐type analysis was performed on 78 stocks of the marine hypotrich ciliate, Aspidisca sp., from a sufficient number of diverse geographic locations, some widely separated. Evidence is provided for the existence of a binary mating system in this “morphospecies.” The collected stocks have been challenged by the most rigorous criterion, namely breeding affinity in the laboratory, and have yielded at least four reproductively, not necessarily geographically, isolated groups that are in fact “biological species,” here referred to as “syngens.” Different syngens contain different pairs of mating types. Syngens are morphologically indistinguishable; hence Aspidisca sp. can be considered a conservative taxon comprising a number of “cryptic” or “sibling species.” Information is also presented about the mating behavior and the pattern of nuclear events at conjugation in Aspidisca sp. Search for soluble pheromones of the mating types gave only negative results. Hence, direct contact with potential partners is postulated to play a critical role in preparing individuals to mate. Mating reaction and mating which actually involves cross‐fertilization (conjugation, sensu stricto) are completely inhibited by 10 μg/ml cycloheximide, suggesting the necessity of protein synthesis for recognition and union in conjugation of potential partners.
A Fast Electrophoretic Isoenzyme Technique for the Identification of Invasive and Non‐Invasive Entamoeba histolytica and “E. hitolytica‐like” Organisms
Authors: MOSS DELYNN M. , MATHEWS HENRY M.
Published: May 2007

Cellulose acetate electrophoresis (CAE) was used to separate glucosephosphate isomerase, hexokinase, malic enzyme, and phosphoglucomutase extracted from invasive and non‐invasive Entamoeba histolytica and “E. histolytica‐like” organisms. Each of these morphologically similar organisms possessed a unique CAE isoenzyme profile that can be used as an aid in their identification. The CAE technique used to obtain these isoenzyme profiles is rapid, simple, and economical, and it requires neither specialized training nor claborate equipment.
Effects of Extracellular Potassium on Acid Release and Motility Initiation in Toxoplasma gondii
Authors: ENDO TAKURO , TOKUDA HAJIME , YAGITA KENJI , KOYAMA TSUTOMU
Published: May 2007

The internal pH (pHi) of Toxoplasma gondii was estimated by measuring the accumulation of the weak base 9‐aminoacridine in buffers with various ionic compositions. The pHi of the metabolizing parasite increased when the extracellular K+ was elevated in alkaline medium or when the external pH (pHc) was substantially increased in medium employing high external K+ (90 mM). The parasite in mouse peritoneal fluid, or in potassium sulfate buffer (pH 8.2), where the pHi was demonstrated to be increased to 7.9, became motile when acidic buffer was substituted for the original suspension medium. This acid‐induced independent movement subsided within 5 min but was repeatedly induced if the pHc was serially lowered to 6.0. Basic buffers, on the other hand, abolished motility when applied to the moving parasites. Nigericin, which is known to collapse pH gradients across the membrane, also abolished motility.
Serology of Naegleria fowleri and Naegleria lovaniensis in a Hospital Survey1
Authors: DUBRAY BARBARA L. , WILHELM WALTER E. , JENNINGS B. R.
Published: May 2007

An avidin‐biotin horseradish peroxidase method was used to detect antibodies to Naegleria fowleri and N. lovaniensis in human serum samples. Antibodies were detected in 101 specimens from 115 hospital patients ranging in age from 15 to 98 years. Class‐specific anti‐immunoglobulins identified antibodies as IgG and IgM. IgG antibody titers to both species ranged from 1:20 to 1:640. Seven of 15 serum samples collected from newborn infants also demonstrated IgG antibodies to these organisms with a titer range of 1:20 to 1:80. The immunoperoxidase test and Western blot analysis of selected serum samples demonstrated a close similarity in serological results between N. fowleri and N. lovaniensis.
Intestinal Ciliated Protozoa of African Rhinoceros: Two New Genera and Five New Species from the White Rhino (Ceratotherium simum Burchell, 1817)1
Authors: VAN HOVEN W. , GILCHRIST F. M. C. , HAMILTON‐ATTWELL V. L.
Published: May 2007

This report represents the first published information on intestinal ciliated protozoa in the African white rhinoceros (Ceratotherium simum Burchell, 1817). Two new genera which do not relate to any known ciliated protozoa from the intestines of mammals and five new species are described. The ciliates were found in the colon of three of these free‐living hindgut‐fermenting grazers that were shot in widely spaced districts in southern Africa. Phalodinium digitalis n. gen., n. sp., Arachnodinium noveni n. gen., n. sp., Monoposthium vulgaris n. sp., M. bracchium n. sp., and M. latus n. sp. constituted between 1% and 10% of the total ciliate population (ca. 1 × 105/ml digesta) in the ascending colon. Exceedingly small numbers were observed in the descending colon, indicating temporary accommodation only.
Trypanosoma humboldti n. sp. from the Chilean Catshark, Schroederichthys chilensis (Guichenot, 1848)1
Authors: MORILLAS J. , GEORGE‐NASCIMENTO M. , VALERIA H. , KHAN R. A.
Published: May 2007

The morphology of Trypanosoma humboldti n. sp. is described from living and stained specimens obtained from the blood of a catshark, Schroederichthys chilensis. This represents the first report of a trypanosome in fish from the eastern Pacific Ocean. It is distinguished by its size and apparent lack of pleomorphism. The presence of a leech, Branchellion ravenellii, attached to the catshark, raises the possibility that it can act as a vector. Additionally, this leech is recorded for the first time from the Pacific Ocean.
The Number of Species of Rodent Coccidia and of Other Protozoa
Authors: Levine Norman D.
Published: May 2007

About 447 species of coccidia have been named from the 1687 living, known species of rodents; 207 host species, 92 host genera, and 15 host families are represented; this is about 12% of the known species of rodents. About 4600 species of apicomplexan protozoa have been named. Assuming that the same proportion of the total number of apicomplexan species has been named as of the coccidian species, there must actually be about 38,333 species of apicomplexan protozoa. There are 5.4 times as many protozoan genera as of apicomplexan genera. Assuming that the number of species in each genus is the same for all the protozoa as it is for the Apicomplexa there may actually be 206,998 species of protozoa. This may be too conservative an estimate. Based on other criteria, an estimate of over 20 million species could be made.
Isolation of a Methanogenic Endosymbiont of the Sapropelic Amoeba Pelomyxa palustris Greeff
Authors: BRUGGEN J. J. A. VAN , RENS G. L. M. VAN , GEERTMAN E. J. M. , ZWART K. B. , STUMM C. K. , VOGELS G. D.
Published: May 2007

ABSTRACT. One of the two methanogenic endosymbionts of the giant sapropelic amoeba Pelomyxa palustris was isolated in pure culture. The cells were slender non‐motile rods (3 × 0.4 μm), sometimes occurring in chains of 3–4 cells. Ultrathin sections revealed a Gram‐positive cell wall and conically pointed ends with mesosome‐like structures in the cytoplasm. The isolate had a generation time of 10 and 12 h during growth on H2/CO2 and formate, respectively. The optimum growth temperature was 40°C and the optimum pH was 7.8. The G+C content of its DNA was found to be 37.7% mole percent. The isolate was identified as Methanobacterium formicicum.
Coccidian Parasites (Apicomplexa: Eimeriidae) from Insectivores. V. Ten Forms from the Moles of Japan (Euroscaptor, Mogera spp.)1
Authors: DUSZYNSKI DONALD W. , WATTAM ALICE R.
Published: May 2007

ABSTRACT. Moles from Japan were examined for coccidian oocysts, and 67 of 77 (87%) hosts were infected including 8 of 11 (73%) Euroscaptor mizura, 31 of 36 (86%) Mogera kobeae, 17 of 17 M. tokudae, and 11 of 13 (85%) M. wogura. Of 67 infected hosts, 57 (85%) had multiple infections representing 2–5 coccidian species when examined. All oocysts in the infected fecal samples remained unsporulated and the absence of sporulation may be the result of storing feces from Japanese moles in 2% aqueous H2SO4. Five structurally distinct forms of unsporulated oocysts were found in E. mizura, and five distinct forms of unsporulated oocysts were also seen in Mogera spp. Two of the forms from E. mizura were similar to forms from Mogera spp., and the five forms from Mogera were shared freely between the three Mogera species. This is the first systematic survey of Japanese moles for coccidia.
A Cytological Study and Reclassification of Trichophrya collini (Saedeleer & Tellier)1
Authors: MOGENSEN METTE M. , BUTLER R. D.
Published: May 2007

ABSTRACT. Trichophrya collini has a polygonal, dorsoventrally flattened body (up to 75 μm diam.), with capitate tentacles arranged in 1–3 rows within peripheral fascicles. There is a central polymorphic macronucleus, an associated micronucleus, and numerous peripheral contractile vacuoles with ventral discharge pores. The cell has a multilayered cortex and the cytoplasm contains suctorian organelles such as crescentic bodies, elongate dense bodies, and haptocysts. The highly contractile tentacles have an axoneme with an outer ring of 24 microtubules separated into six groups and an inner ring of six curved lamellae, each with five microtubules. The lamellae at the distal and proximal ends of the axoneme are arranged in a helix, and the outer ring microtubules are joined in a distal connective sheath. In the apical knob of the tentacle, the haptocysts are borne on a central capsule, Reproduction is by endogenous budding to produce a single oval‐shaped swarmer, with equatorial ciliature, which metamorphoses within 3 h. These observations suggest that this organism, previously known as Heliophrya collini Saedeleer & Tellier, is synonymous with Platophrya rotunda Gönnert, Craspedophrya rotunda Rieder, and Heliophrya rotunda Matthes. Its endogenous mode of budding assigns it to the genus Trichophrya. but it is distinct from Trichophrya rotunda Hentschel, and should be reclassified to Trichophrya collini (Saedeleer & Tellier).
A Monoclonal Antibody to Alpha Tubulin Recognizes Host Cell and Trypanosoma cruzi Tubulins1
Authors: PAULIN JEROME J. , KEITH CHARLES H. , TARLETON RICK L.
Published: May 2007

ABSTRACT. A mouse monoclonal anti‐α‐tubulin antibody was used to investigate the disposition of the cytoskeletal microtubules of three tissue culture cell lines–J774 macrophages, BSC‐1, and Vero cells–infected with the Brazil strain of Trypanosoma cruzi. Indirect immunofluorescence light microscopy was used to demonstrate the antigenic response in host cells and parasites, simultaneously. In all morphotypes of T. cruzi, the monoclonal antibody reacted with all subpopulations of microtubules, inclusively, the subpellicular, flagellar, cytopharyngeal, and mitotic. The host cell cytoskeletal microtubule framework was revealed and the redistribution and destruction of the microtubular lattice in response to parasite infection over a 120 h period recorded. Our results show that after the initial inoculation of tissue cultures with trypomastigotes, the parasites penetrate the cells and locate in the perinuclear region of the cell where they multiply. The number and distribution of host cell microtubules were altered during the infection. The normal radial distribution of microtubules extending from the center of the cell to the periphery was destroyed. The remaining microtubules were observed at the periphery encircling, but well removed from the proliferating parasites. The complete transformation of the parasites was monitored throughout the infection with the end result being the liberation of parasites and the near complete destruction of the microtubular framework of the host cell. A residual population of dividing spheromastigotes was observed in cells liberating trypomastigotes. Colloidal gold labeling of thin sections as seen in the electron microscope affirmed the specificity of our monoclonal antibody to all subpopulations of microtubules in T. cruzi.
Ciliate Protozoa in the Rumen of Kenyan Zebu Cattle, Bos taurus indicus, with the Description of Four New Species1
Authors: IMAI SOICHI
Published: May 2007

ABSTRACT. The composition of the fauna of rumen ciliates in zebu cattle in Kenya was surveyed and 13 genera containing 51 species with 19 formae were identified. Four new species were recognized, then described as Diplodinium africanum n. sp., Diplodinium nanum n. sp., Eudiplodinium kenyensis n. sp., and Ostracodinium iwawoi n. sp. In addition, Buetschlia triciliata and Ostracodinium stokyi were found for the second and third times and described as Hsiungia triciliata n. comb. and Enoploplastron stokyi n. stat., with two formae, respectively. The species composition was similar to that of Indian zebu but several species were considered to originate from African native ruminants. In the percentage composition of genera, the numbers of Entodinium, which normally predominate in rumens in other areas, were very low.
Developmental Polymorphism Induced by Intraspecific Predation in the Ciliated Protozoon Onychodromus quadricornutus1
Authors: WICKLOW BARRY J.
Published: May 2007

ABSTRACT. The hypotrich ciliate Onychodromus quadricornutus is remarkable in its potential for voluminous size (up to 900 μm in length), its possession of a unique set of four dorsal spines or horns, and its capability to express two kinds of developmental polymorphism induced by intraspecific predation. Cell length frequencies in replicates of a well‐fed clone show normal distributions; starvation followed by intraspecific predation, however, induces cells within a clone to transform into two size classes: small lanceolate cells and cannibal giants. Induction experiments indicate that a substance released by cannibal giants stimulates defensive spine growth in clonemates within 24 h. Giants can also induce spine growth in non‐clonemates. Furthermore, O. quadricornutus cells exposed to the predacious ciliate Lembadion magnum also develop hypertrophied spines. Selection experiments show that conspecific giants prey on cells with undeveloped spines (< 20 μm in length) to a much greater extent than on cells with developed spines (>40 μm in length). Transformation of a population of similarly sized O. quadricornutus cells into two different size classes may function to increase the range of potential prey sizes available to the O. quadricornutus population; hypertrophied spines appear to function as an inducible defense against intermittent predators appearing in the system including conspecific giants. This is the first reported case of a defensive developmental polymorphism induced by intraspecific predation.
Prevalence of Eimeria spp. (Apicomplexa: Eimeriidae) in Oregon Llamas1
Authors: RICKARD LORA G. , BISHOP JANELL K.
Published: May 2007

Eimeria alpacae, E. punoensis, E. lamae, and E. macusaniensis were identified in fecal samples from 189 llama (Lama glama (L.)) adults and 50 llama crias (animals less than one year of age of any species in the genus Lama) from central and western Oregon. In both adults and crias, E. alpacae was the most common species found. The least common was E. macusaniensis, which was found in only two adults. Overall prevalence and numbers of animals with mixed infections was approximately twice as high in crias as in adults.
Protein Synthesis in Isolated Symbionts from the Flagellate Protozoon Crithidia deanei1
Authors: NOVAK ESTELA , HAAPALAINEN EDNA FREYMULLER , DA SILVA SOLANGE , DA SILVEIRA JOSE FRANCO
Published: May 2007

Here we describe a method that allows the isolation of intact trypanosomatid symbionts in amounts sufficient for biochemical analysis. The isolated symbionts retain their characteristic morphological features and are reasonably free of subcellular debris. They actively incorporate [3H]leucine and [35S]methionine into proteins. Chloramphenicol and rifampicin at 50 μg/ml almost completely inhibit the incorporation of protein precursors. The inhibition of protein synthesis by the antibiotics provides direct evidence for the existence of a prokaryotic protein‐synthesizing system in this unusual intracellular structure. The pattern of protein synthesis of the isolated symbionts is complex. Several symbiont polypeptides are absent or poorly represented in the flagellate.
Calcium Regulates the Regeneration of Cilia in Tetrahymena thermophila
Authors: JOGLAR‐RAMIREZ JOSE A. , RENAUD FERNANDO L.
Published: May 2007

A study of calcium metabolism in Tetrahymena during the regeneration of cilia evidenced that the process is inhibited by nifedipine and trifluoperazine. This suggests that calcium ions play an important regulatory role in this process. This was confirmed by studies on calcium uptake and efflux which showed that there was a net increase in calcium uptake prior to the reinitiation of motility. The increase coincided with a period of sensitivity to the calcium antagonist TMB‐8 and with an increase in the intracellular level of cGMP. The process was also inhibited by neomycin and stimulated by phorbol esters, which suggests that hydrolysis of phosphatidylinositol phosphates may take place as part of the calcium regulatory network during the regeneration of cilia.
Characterization of DNA from the Dinoflagellate Woloszynskia bostoniensis1
Authors: DAVIES W. , JAKOBSEN K. S. , NORDBY ø.
Published: May 2007

Some physical and chemical properties of DNA isolated from the dinoflagellate Woloszynskia bostoniensis were determined. Analytical cesium chloride gradient centrifugation gave a major component and a minor component banding at 1.719 and 1.693 g/cm, respectively. Thermal denaturation in 0.1 SSC showed a broad transition with a Tm of 70.5° C. Derivation of this curve indicated that two components were present having Tm values of 66° C and 70° C. Base composition analysis showed a GC content of 48.1% and a high degree of thymine replacement by 5‐hydroxymethyluracil. Two minor bases, identified as 5‐methylcytosine and N6‐methyladenine, were also detected. Reassociation kinetics showed a typical eukaryotic reassociation pattern with 45% repetitive and 55% single copy sequences.
Maintenance of Integrity, Viability, and Adhesion of Entamoeba histolytica Trophozoites in Different Incubation Media12
Authors: CANO‐MANCERA RAFAEL , LÓPEZ‐REVILLA RUBÉN
Published: May 2007

We have determined the integrity, viability and adhesion of Entamoeba histolytica HK9 and HM1 trophozoites during their incubation in two basal culture media (TP and TYI) and three saline media (“maintenance medium” MM‐1 and two others buffered with HEPES). In basal culture media, more than 70% of the trophozoites maintained their integrity and adhesion to human red blood cells (RBC) for up to 4 h, and the proportion of those excluding Trypan blue decreased slowly after 2 h. In saline media, the number of ameba‐RBC complexes reached a maximum after 20–30 min and then decreased rapidly (and fastest in MM‐1), less than 10% of the amebae were intact after 3–4 h, and dye exclusion fell abruptly from the start of incubation. The number of ameba‐RBC complexes formed and the rate of adhesion were highest in basal TP medium. Normal nonvacuolated refringent (NVR) trophozoites deteriorated progressively in all media—although much faster in the saline ones—to vacuolated refringent (VR), nonrefringent, and disrupted. Trypan blue was excluded by all NVR and a fraction of the VR trophozoites. Horse serum helped to maintain ameba integrity and viability, but inhibited adhesion in a concentration‐dependent manner. We conclude that E. histolytica trophozoite integrity and adhesion are adequately preserved and should be characterized only in basal culture media, that refringence without vacuolization is a more stringent characteristic of ameba quality than Trypan blue exclusion, and that some serum component inhibits ameba adhesion.
Establishment of Endoreticulatus N. G. for Pleistophora fidelis (Hostounský & Weiser, 1975) (Microsporida: Pleistophoridae) Based on the Ultrastructure of a Microsporidium in the Colorado Potato Beetle, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae)1,2
Authors: BROOKS W. M. , BECNEL J. J. , KENNEDY G. G.
Published: May 2007

A new genus, Endoreticulatus n. g., is described for the microsporidium Pleistophora fidelis (Hostounský & Weiser, 1975) based on light and electron microscopic studies of a microsporidium in the Colorado potato beetle, Leptinotarsa decemlineata (Say). This latter microsporidium is considered to be conspecific with P. fidelis because both isolates have been shown to be infectious for L. decemlineata where infection is limited to the epithelial cells of the midgut; both are haplokaryotic and develop as groups of sporoblasts and spores in subpersistent vacuoles in the host cell. In addition, meronts, sporonts, and spores of each isolate often occur simultaneously in a common cell, and by light microscopy they both appear similar. Ultrastructural studies of the isolate from L. decemlineata revealed that all developmental stages occur in parasitophorous vacuoles derived from cisternae of rough endoplasmic reticulum of the host cell cytoplasm. Based on the unique nature of the parasitophorous vacuole, a new genus, Endoreticulatus, is proposed for P. fidelis. The genus is compared with the other genera whose species undergo multisporous sporogony in sporophorous vesicles. In addition, the nature of the parasitophorous vacuole of Endoreticulatus fidelis (Hostounský & Weiser, 1975) n. comb. is compared with the parasitophorous vacuole known to encase various developmental stages of several other microsporidian species.
Compartmentation and Activities of Enzymes Involved in the Metabolism of Amino Acids Implicated in Osmoregulatory Mechanisms in Acanthamoeba castellanii1
Authors: HELLEBUST JOHAN A. , LAROCHELLE JACQUES
Published: May 2007

Glutamate dehydrogenase in Acanthamoeba castellanii is an NAD‐dependent cytosolic enzyme. This is similar to glutamate dehydrogenases in Phycomycetes, but very different from the dual coenzyme‐specific enzymes located in mitochondria in animals and in mitochondria and chloroplasts in higher plants. Pyrroline‐5‐carboxylate (P‐5‐C) reductase occurs also in the cytoplasm in A. castellanii and has very high affinities for L‐P‐5‐C (Km= 12 μM) and NADH (Km= 15 μM). In contrast, ornithine aminotransferase and proline oxidase are mitochondrial enzymes. No proline‐inhibited γ‐glutamyl kinase was detected while an active glutamine synthetase was found in the cytosolic compartment. Evidence for a mitochondrial transport system for L‐proline was obtained. Two possible pathways for proline biosynthesis in A. castellanii are discussed based on information obtained about activities and subcellular compartmentation of enzymes.
Progress in Taxonomy of the Apicomplexan Protozoa
Authors: LEVINE NORMAN D.
Published: May 2007

In 1987, 4516 species and 339 genera of the phylum Apicomplexa had been named. They consisted of the gregarines (subclass Gregarinasida) (1624 named species and 231 named genera), the hemogregarines (family Haemogregarinidae) (399 species and 4 genera), the eimeriorins (order Eimeriorida) (1771 species and 43 genera), the hemospororids (order Haemospororida) (444 species and 9 genera), the piroplasmids (order Piroplasmorida) (173 species and 20 genera), and a few others (105 species and 32 genera). The first apicomplexan protozoon was seen by Antony van Leeuwenhoek; in 1674 he saw oocysts ofEimeria stiedaiin the gall bladder of a rabbit. The first member of the phylum to be named (by Dufour in 1828) wasGregarina ovatain earwigs. During the quarter century 1826–1850, 41 species and 6 genera of Apicomplexa were named. These numbers increased progressively. In the quarter century 1951–1975, 1873 new species and 83 new genera were named. Data are given for the numbers of named species and genera of apicomplexan protozoa of each group known in 1850, 1875, 1900, 1925, 1950, 1975, and 1987.
Eimeria saudiensis N. Sp. (Apicomplexa: Eimeriidae) from the Arabian Oryx (Oryx leucoryx) in Saudi Arabia
Authors: KASIM AHMED A. , AL SHAWA YASER R.
Published: May 2007

Oocysts of Eimeria saudiensis n. sp. (Apicomplexa: Eimeriidae) are described from the feces of the Arabian oryx, Oryx leucoryx, from the Riyadh Zoo, Saudi Arabia. The oocysts were ellipsoidal or slightly ovoid, 31.2 times 24.5 (24.3–36.5 times 20.0–27.6) μm with a bilayered wall about 1.7 μm thick. The micropyle was covered by a dome‐shaped cap. The oocyst residuum was absent, but tiny polar granules were present. The sporocysts were elongate ovoid, 14.3 times 7.2 (11.5–18.5 times 6.0–9.0) μm, had a Stieda body, but lacked a substiedal body. The sporocyst residuum was present, composed of numerous small granules. The sporozoites were elongate club‐shaped, and contained two prominent refractile bodies.
Fatal Toxoplasmosis and Enteroepithelial Stages of Toxoplasma gondii in a Pallas Cat (Felis manul)1
Authors: DUBEY J. P. , GENDRON‐FITZPATRICK A. P. , LENHARD ANDREA L. , BOWMAN D.
Published: May 2007

Toxoplasma gondii was found in tissues of a six‐year‐old female Pallas cat (Felis manul) from the Milwaukee County Zoo. Toxoplasma gondii meronts (types D and E), gamonts, and oocysts were present in the epithelium of the small intestine. Numerous unsporulated oocysts were present in the intestinal lumen. The cat died of acute, overwhelming toxoplasmosis. Necrotic enteritis, multifocal necrotizing granulomatous hepatitis, and pneumonia were the prominent lesions.
Feeding of a Freshwater Flagellate, Bodo saltans, on Diverse Bacteria1
Authors: MITCHELL GARY C. , BAKER J. H. , SLEIGH M. A.
Published: May 2007

ABSTRACT Bodo saltans was isolated from a chalk stream and fed with pure cultures of seven bacteria obtained from the same river. The flagellates were allowed to migrate into suspensions of either of two bacterial species in a T‐maze at 20–22°C. There was a significant difference (P < 0.01) between the numbers of flagellates which migrated into suspensions of different bacteria, which were subsequently arranged in an order of “attractiveness” to the flagellate. Bodo saltans grew successfully in monoxenic suspensions of all seven bacterial strains, but more rapid growth occurred with non‐flagellated than with flagellated bacteria; this may be because while feeding, B. saltans tends to associate with surfaces where non‐flagellated bacteria may also congregate. The efficiency with which B. saltans is able to utilize different bacteria may be influenced by the motility or secretory activities of the bacteria. There was no incontrovertible evidence that B. saltans responds to specific bacterial attractants.
Ultrastructure of Mitosis in Entosiphon sulcatum (Euglenida)1
Authors: TRIEMER RICHARD E.
Published: May 2007

ABSTRACT The ultrastructural features of cell division in the biflagellate, phagotrophic euglenoid, Entosiphon sulcatum, have been examined. Prophase is marked by the appearance of daughter feeding apparatuses and the emergence of two additional flagella. Pairs of flagella begin to migrate laterally along the surface of the elongating nucleus and remain lateral to the developing spindle poles. As the nucleolus elongates, it becomes dumbbell‐shaped and the chromosomes move to the center of the nucleus, forming a loosely organized metaphase plate. Microtubules from opposing spindle poles attach to one of the pair of kinetochores found on each chromosome. The initial chromosome separation occurs during anaphase as the nucleus elongates. The length of the chromosomal microtubules does not decrease until late anaphase/early telophase. As the nucleus elongates, it forms a dumbbell‐shaped structure. Most of the remaining microtubules are positioned in the interzone between the forming daughter nuclei. The interzonal spindle becomes somewhat constricted but remains intact until it is broken by the impinging cleavage furrow. Replication of the pellicular strips is not completed until late in cytokinesis.
Freeze‐Fracture Study of the Trophozoite and the Cyst of Entamoeba histolytica
Authors: YOSHIKAWA HISAO , YAMADA MINORU , YOSHIDA YUKIO
Published: May 2007

ABSTRACT The fine structure of the trophozoite and cyst of Entamoeba histolytica from the stool of a patient was compared using the freeze‐fracture method. The intramembranous particles (IMP's) were heterogeneously distributed on the plasma membrane of the trophozoite and their density was 1139 ± 105/μm2 on the P face and 27 ± 9/μm2 on the E face. Particle‐rich depressions and linear particle arrays, reported by other investigators on cultured trophozoites, were also observed on the P face while on the E face such special particle arrangement was not recognized. Particle‐free, small protrusions were frequently observed on the P face of the trophozoite membrane. The existence of these protrusions is a new finding. In the cyst, the IMP's were also distributed heterogeneously on both the P and E faces of the plasma membrane. The density of the IMP's, however, was much lower than in the trophozoite: 6 ± 2/μm2 on the P face and averaging less than 1/μm2 on the E face. In freeze‐fracture images, the plasma membrane of the cyst showed a variety of configurations from smooth to uneven or ridged surfaces. These morphological alterations of the plasma membrane may be attributed to the aging of the cyst. The thick wall of the cyst had a filamentous tri‐ or tetra‐lamellar structure. The cytoplasm of the cyst was similar in structure to that of the trophozoite and the diameter of the nuclear pores was equal in both trophozoites and cysts.
Structural and Biochemical Characterization of Isolated Trichocysts of the Ciliate Pseudomicrothorax dubius1
Authors: EPERON SIMONE , PECK ROBERT K.
Published: May 2007

ABSTRACT Trichocysts of Pseudomicrothorax dubius were ejected by 15% ethanol in phosphate‐buffered culture medium (CM) and purified on discontinuous sucrose gradients, in which they concentrated in the lower part of the 27% phase and in the 57% phase. These phases were washed by 15% ethanol in CM, or by CM alone, and pooled. Ejected trichocysts observed by Nomarski interference contrast microscopy and after negative‐staining for electron microscopy show a shaft with periodic cross‐bands and four opened‐out arms, sometimes with electron‐dense droplets at both ends of each arm. On SDS‐PAGE, trichocysts show ˜20 protein bands. The major bands are at 31 and 30 kD (G1), 27 and 26.5 kD (G2), 25 kD, 23 kD, and six bands at 15–20 kD (G3). Minor bands are observed above 30 kD, among them ciliary components which contaminate the trichocyst fraction. The trichocyst banding pattern was reproducible with different ejection media; however, the 30 kD disappeared when the buffered ejection medium contained no added Ca2+ or contained EDTA. When the trichocyst extract is solubilized in sample buffer without 2‐mercaptoethanol, the major trichocyst bands are those of G1 and bands at 32.5–35 kD and 41 kD, which appear to be dimers of a few of the G3 proteins. On two‐dimensional gels of trichocysts, ˜40 acidic protein spots are resolved with pI's of 4.6–6.6. On Western blots of two‐dimensional gels, glycoproteins were revealed by Concavalin A‐peroxidase labeling in three spots of G3, in two spots at 23 kD, in all five spots of G1, and in seven spots over 35 kD.
A Procedure for Comparing Growing and Non‐growing Tetrahymena Cultures: Ribonucleotide Pools in Tetrahymena Starved for the Essential Amino Acid Histidine1
Authors: GROVE BARBARA F. , CONNER ROBERT L.
Published: May 2007

ABSTRACT A new starvation procedure permitted the study of early events in a protozoon's growth cycle. Growing cultures of Tetrahymena that differed from non‐growing cultures by one variable were produced by adding histidine to cells deprived of that amino acid in an otherwise complete medium. Alterations of the nucleotide pools were examined in +His and in ‐His cultures in the period preceding RNA synthesis by cells in +His medium. High performance liquid chromatographic analysis provided a balance sheet for the difference in purine compounds in the two cultures. The change in rNTP levels occurred only when the cells were resuspended in a fresh medium and was not a function of cell density. These observations point to the presence of a factor(s) in the old medium that inhibits the energy charge increase in rNTP and in purine accumulation.
Effects of Cold and Nocodazole Treatments on the Microtubular Systems of Paramecium in Interphase
Authors: TORRES ANTONIO , DELGADO PILAR
Published: May 2007

The sensitivity of the microtubular systems to cold and nocodazole treatments as well as the cellular distribution of microtubules containing acetylated a‐tubulin have been studied in Paramecium. Our results indicate that the microtubular systems of Paramecium show marked differences in stability. Cold and nocodazole treatments produce the depolymerization of the major part of the cytoplasmic microtubular network while the cortical structures remain stable under treatment. This differential stability of the microtubular systems is associated with the acetylation of the a‐tubulin. The use of the antibody 6‐11B‐1, specific for acetylated α‐tubulin, shows that the microtubular systems containing acetylated a‐tubulin are the same as those that remain stable after depoly‐merizing treatments. Finally, the images obtained during the repolymerization by heating suggest that the cortical dikinetids are able to nucleate the microtubules of the cytoplasmic network.
Development of Edhazardia aedis (Kudo, 1930) N. G., N. Comb. (Microsporida: Amblyosporidae) in the Mosquito Aedes aegypti (L.) (Diptera: Culicidae)
Authors: BECNEL JAMES J. , SPRAGUE VICTOR , FUKUDA TOKUO , HAZARD EDWIN I.
Published: May 2007

A microspondium of the mosquito Aedes aegypti (L.), identified as Nosema aedis Kudo, 1930, was found to be a heterosporous species with 3 sporulation sequences. Usually, I sequence developed in a parental generation host individual that was infected per os as a larva and the other 2 developed concurrently in a filial host larva that was infected transovarially. Under some conditions there were deviations from the parental host‐filial host alternation. The 1st sporulation sequence was diplokaryotic (diploid in a particular sense) throughout; the other 2 arose from diplokaryotic meronts, developed concurrently and ended with haploid spores. Haplosis in 1 case was by means of dissociation of the diplokaryon. In the other case it was by meiosis. Conflicting reports about whether the members of the diplokaryon in the latter sequence separate and undergo meiosis individually or coalesce and undergo meiosis as I nucleus were resolved in favor of the latter idea. A new genus in family Amblyosporidae was created to contain this species. which then became Edhazardia aedis (Kudo. 1930) n. g., n. comb.
Analysis of Coccidian Oocyst Populations by Means of Flow Cytometry
Authors: FULLER A. LORRAINE , McDOUGALD L. R.
Published: May 2007

Flow cytometry was employed as a tool to analyze and characterize batches of oocysts from laboratory and field isolates of Eimeria spp. from chickens and to propagate sub‐populations of batches of oocysts. Oocyst batches were cleaned of debris by a combination of salt flotation, washing and treatment with dilute sodium hypochlorite (1.5% aqueous). Oocyst size and shape were registered by forward‐angle light scatter with the argon laser excitation set at 488 nm at 300 mW. Sub‐populations of oocysts were collected by map gating and used for microscopy or for propagation. The profile of particle size was characteristic for each species. Propagation of sub‐populations of oocysts of specified sizes resulted in cultures of coccidia that were pure species or nearly pure species. The small size of E. mills caused difficulty in separation from the remaining fine debris. This technique was useful for studying the variation in oocyst size within populations and characterization of field isolates of mixed species. Propagation of pure species from mixed isolates by bit‐map gating had the same limitations as micromanipulation because of the overlapping size of Eimeria spp. Chancaerization is further limited by the lack of suitable size/shape standards for flow cytometry‐Key words. Cell sorter. Eimeria spp., oocyst shape, oocyst size.
Some Factors Inducing Formation of Metacyclic Stages of Trypanosoma cruzi
Authors: HOMSV JAMES J. , GRANGER BARBARA , KRASSNER STUART M.
Published: May 2007

ABSTRACT Epimastigotes of Trypanosoma cruzi, Peru strain, incubated in Contreras’artificial triatomine urine transformed into metacyclic trypomastigotes within 48 h at 28° C when 10 mM L‐proline or L‐glutamate was added to the medium. Smaller numbers of metacyclic stages were induced in the presence of glucose or L‐alanine. The L‐leucine and L‐isoleucine, 2 amino acids known to inhibit proline catabolism, inhibited proiine‐induced metacyclogenesis. Cells gassed with 5% CO2 showed significantly faster rates and higher levels of transformation than those not gassed, therefore indicating the additional importance of CO2 for transformation.
Cannibalism and Coprophagy Are Modes of Transmission of Blastocrithidia triatomae (Trypanosomatidae) between Triatomines
Authors: SCHAUB GUNTER A. , BÖKER CORNELIA A. , JENSEN CORD , REDUTH DAGMAR
Published: May 2007

Transovarial transmission was not detectable among Blastocrithidia triatomae‐ infected Triatoma infestans. Rather, B. triatomae was transmitted directiy between triatomines by cannibalism and coprophagy. Cannibalism conditions that excluded coprophagy always resulted in an infection of Dipetalogaster maxima. The efficiency of transmission was not influenced by the blood source—mice or chickens—fed to the infected donor bugs although chicken blood lyses the epimastigotes of the stomach population. Triatoma infestans was infected by coprophagy only if fed, not if unfed. Blastocrithidia triatomae in dry feces was taken up only if the feces were redissolved in fresh feces. Infections also appeared in groups of bugs fed on chickens previously used for feeding infected bugs.
Isospora peromysci Davis, 1967 (Apicomplexa: Eimeriidae) in Peromyscus leucopus and P. maniculatus (Rodentia: Cricetidae) from Texas
Authors: McALLISTER CHRIS T. , UPTON STEVE J.
Published: May 2007

Oocysts of Isospora peromysci (Davis, 1967) (Apicomplexa: Eimeriidae) were recovered from the feces of 1/30 (3.3%) white‐footed mice, Peromyscus leucopus, in Johnson County, Texas. This report represents a new host and geographic record for the parasite. The coccidium was also found in 1/20 (5.0%) deer mice, P. maniculatus, from the same locale. Morphological data are provided on the sporulated oocyst of I. peromysci and comparisons are made with previously published information on the species from other geographic localities.