Eukaryotic microbiology

ABSTRACT. Ichthyobodo necator is an important fish ectoparasite with a broad host and ecological range. A novel method, involving the use of an anesthetic, allowed the collection of large numbers of parasites from the skin and gills of hybrid striped bass (Morone saxatilis male ×M. chrysops female). Genomic DNA from these samples was used to amplify and clone the 18S rRNA gene. The 18S rRNA gene was similarly cloned from Bodo caudatus, Bodo edax, Bodo saltans, an unidentified Bodo species, and Dimastigella trypaniformis. The resulting sequences were aligned with other representative kinetoplastid species using pileup and similarities in secondary structure. Phylogenetic relationships within the suborder Bodonina and representatives of the suborder Trypanosomatina were determined using maximum‐likelihood statistics. The phylogenetic analyses strongly supported the order Kinetoplastida as a monophyletic assemblage consisting of at least two major lineages. One lineage consisted exclus...

Molecular phylogenetic analysis of 18S rRNA gene sequences of nearly any species of Chytridiomycota has typically challenged traditional classification and triggered taxonomic revision. This has often led to the establishment of new taxa which, normally, appear well supported by zoospore ultrastructure as diagnostic character. To construct a meaningful and comprehensive classification of Chytridiomycota, the combination of molecular phylogeny and morphological studies of traditionally defined chytrid species is needed. In this work, we have studied morphological and ultrastructural features based on light and transmission electron microscopy as well as molecular phylogenetic analysis of a parasite of the yellow-green alga Tribonema gayanum (strain X-124 CCPP ZIN RAS) morphologically similar to Rhizophydium granulosporum. Phylogenetic analysis of the 18S rRNA gene sequence of this strain supports that it represents a new genus and species affiliated to the recently established order Gromochytriales. The ultrastructure of X-124 confirms its phylogenetic position sister to Gromochytrium and serves as the basis for the description of the new genus and species Apiochytrium granulosporum.

ABSTRACT. Dinoflagellates have among the largest nuclear genomes known, but we know little about their contents or organisation. Given the interest in dinoflagellate ecology, cell biology, and evolutionary biology, there are many reasons to thoroughly investigate the contents of dinoflagellate genomes, but because of their large size the only thorough samples to date have relied on expressed sequence tag surveys to analyse cDNAs. To complement this, there are some studies of the physical properties of dinoflagellate chromosomes, but no direct survey of the nature of the sequences contained within them. To start to build a picture of the contents of these genomes, we have sequenced over 230,000 bp from the nuclear genome of Heterocapsa triquetra, which has been estimated to be 18–23 billion base pairs in total. The survey includes one putative gene with two relict spliced leaders, one putative pseudogene, and a small number of low‐complexity repeats, transposons, and other putative s...

Several species of microsporidia can cause disease in humans in both immunocompromised and immunocompetent individuals. Enterocytozoon bieneusi and Encephalitozoon intestinalis are most commonly associated with chronic diarrhea. All Encephalitozoon species, including E. intestinalis, E. hellem, and E. cuniculi, also cause disseminated infections. As distinctive treatment options are available for the different genera, identification is clinically important. We evaluated a PCR with primers directed to a conserved region of the small subunit rRNA gene of microsporidia. Hybridization with a generic microsporidium probe and specific probes for each of the four different species was used for identification. Probes were labeled with ruthenium and detected by electrochemiluminescence. The sensitivity of the assay was tested with plasmids containing the region of interest from each of the four different species and Vittaforma corneae as a control. In addition, the assay was tested with feces spiked with cultured spores from each of the three Encephalitozoon species and V. corneae. An analytical sensitivity of 3.5 ؋ 10 2 to 3.5 ؋ 10 3 spores per g of feces, corresponding to 17 to 170 gene copies per PCR, was found, which is several orders of magnitude more sensitive than microscopy after Uvitex 2B fluorescent staining. Stool samples from 22 microscopically diagnosed patients and from 61 uninfected controls were evaluated, showing a sensitivity of at least 95% and a specificity of 100% compared to microscopy. The method was further tested by spiking urine samples with spores of the different Encephalitozoon species.

Introduction: Schistosomiasis is a public health concern and there is a need for reliable field-compatible diagnostic methods in endemic settings. The AiDx Assist, an artificial intelligence (AI)-based automated microscope, has shown promising results for the detection of Schistosoma haematobium eggs in urine. It has been further developed to detect Schistosoma mansoni eggs in stool. Methods: In this study, we evaluated the performance of the AiDx Assist for the detection of S. mansoni eggs in stool samples and further validated the performance of the AiDx Assist for the detection of S. haematobium eggs in urine samples. Additionally, the potential of the AiDx Assist for the detection of
other helminths in stool samples was explored. In total, 405 participants from an area endemic for both S. mansoni and S. haematobium provided stool and urine samples which were subjected to AiDx Assist (semi- and fully automated), while conventional microscopy was used as the diagnostic reference. Results: Only samples with complete test results were included in the final analysis, resulting in 375 stool and 398 urine samples, of which 38.4% and 65.3% showed Schistosoma eggs by conventional microscopy. The collected images of the stool samples were retrospectively examined for other helminth eggs via manual analysis. For the detection of S. mansoni eggs, the sensitivity of the semi automated AiDx Assist (86.8%) was significantly higher compared to the fully
automated AiDx Assist (56.9%) while the specificity was comparable, with 81.4% and 86.8%, respectively. Retrospectively, eggs of Ascaris lumbricoides and Trichuris trichiura were visualized. For the examination of urine samples, a comparable sensitivity in the detection of S. haematobium eggs was found between the semi-and the fully automated modes of the AiDx Assist, showing 94.6% and91.9%,respectively. Furthermore, the specificity was comparable, with 90.6%and 91.3% respectively.
Discussion: The AiDx Assist met the World Health Organization Target Product Profile criteria in terms of diagnostic accuracy for the detection of S. haematobium eggs in urine samples and performed modestly in the detection of S. mansoni eggs in stool samples. With some further improvements, it has the potential to become a valuable diagnostic tool for screening multiple helminth parasites in stool and urine samples.

Microsporidium rhabdophilum sp. n. (Microsporida : Pansporoblastina) is described from the microbotrophic nematode Rhabditis mny-iophila Poinar. This microsporidian normally infects the hypodermal and reproductive tissues of the nematode. The parasite possesses small uninucleate, bacilliform spores produced in pansporoblasts. The number of spores per pansporoblast is norrmally 8 or 16 but cari range from 4 to 25. The developmental stages of the parasite are examined ultrastructurally. RESUME Microsporidium rhabdophilum sp. n. (Microsporida : Pansporoblastinal parasite des nématodes Rbabditis myriophila (Rhabdita : Rhabditidael Microsporidium rhabdophilwn sp. n. (Microsporida : Pansporoblastina), provenant des nématodes bacilliphages Rhabditis myriophila Poinar, est décrit. Cette microsporidie infecte normalement l'hypoderme et les tissus de l'appareil reproducteur du nématode. Le parasite posséde de petites spores bacilliformes, uninucléées, produites dans des pansporoblastes. Le nombre de spores par pansporoblaste est normalement de 8 ou 16, mais peut varier de 4 à 25. L'ultrastructure des différents stades de développement du parasite a été étudiée. During routine studies on the development of Rhabditis myriophila

Many high-quality genomes are available for dixenous (two hosts) trypanosomatid species of the genera Trypanosoma, Leishmania, and Phytomonas, but only fragmentary information is available for monoxenous (single-host) trypanosomatids. In trypanosomatids, monoxeny is ancestral to dixeny, thus it is anticipated that the genome sequences of the key monoxenous parasites will be instrumental for both understanding the origin of parasitism and the evolution of dixeny. Here, we present a high-quality genome for Leptomonas pyrrhocoris, which is closely related to the dixenous genus Leishmania. The L. pyrrhocoris genome (30.4 Mbp in 60 scaffolds) encodes 10,148 genes. Using the L. pyrrhocoris genome, we pinpointed genes gained in Leishmania. Among those genes, 20 genes with unknown function had expression patterns in the Leishmania mexicana life cycle suggesting their involvement in virulence. By combining differential expression data for L. mexicana, L. major and Leptomonas seymouri, we hav...

This study examines the mediating effect of fairness perceptions in the relationship between two-way communication in pay system and job satisfaction. Although the relationship between such variables has been generally investigated, the mediating effect of two specific types of fairness perceptions, namely procedural fairness and distributive fairness, has not been thoroughly discussed in organizational pay system research literature. Thus, this study was conducted to fulfil this gap. Self-report questionnaires were utilized to gather data from employees in Malaysian public research universities. The study is also novel in that it utilized SmartPLS to assess the psychometric of measurement scale and then test the research hypotheses. Findings from this study prove that the implementation of two-way pay communication between administrators and employees about pay system has strongly invoked employees’ perceptions of procedural fairness and distributive fairness. Consequently, this fa...

ABSTRACT. Reverse transcription PCRs (RT‐PCRs), real‐time RT‐PCRs and microarrays containing 50‐mer oligonucleotides representing nucleus‐encoded genes for chloroplast proteins from Euglena gracilis were used to compare light‐ and dark‐grown wild‐type mRNA levels to those of light‐ and dark‐grown E. gracilis stable white mutant strains WgmZOflL, W3BUL and W10BSmL. The analyses revealed no light‐dependent regulation of mRNA levels. Moreover, the mRNA levels of most genes were unchanged in all white mutants in comparison with wild‐type. These results suggest that mRNA levels of nucleus‐encoded genes for chloroplast proteins in E. gracilis do not depend on either light or plastid function.

Sex chromosome genes control sex determination and differentiation, but the mechanisms of sex determination in birds are unknown. In this study, we analyzed the gene FEM1C which is highly conserved from Caenorhabditis elegans to higher vertebrates and interacts with the sex determining pathway in C. elegans. We found that FEM1C is located on the Z and W chromosome of zebra finches and probably other Passerine birds, but shows only Z linkage in other avian orders. In the zebra finch, FEM1C-W is degraded because of a point mutation and possibly because of loss of the first exon containing the start methionine. Thus, FEM1C-W appears to have degenerated or been lost from most bird species. FEM1C-Z is expressed in a cytoplasmic location in zebra finch fibroblast cells, as in C. elegans. FEM1C represents an interesting example of evolutionary degradation of a W chromosome gene.

Chemoattraction of Tetrahymena pyriformis, strain GL, was measured during starvation and under different growth conditions. Log phase cells starved in buffer are attracted by certain amino acids, peptides, and proteins. Cysteine, methionine, and phenylalanine are attractants at i0@ M. The peptides in proteose peptone (PP) and yeast extract (YE) are active at 10_6M. Epidermal growth factor (EGF) is active at >3 X i0@ M. Among the proteins, platelet derived growth factor (PDGF) is the most active (3 X 108 M). Cells growing in defined medium are attracted by PP, YE, and some proteins (PDGF). Swimming speed was measured for starved cells with and without added attractants or repellents. With addition of PP the swimming speed increases from 0.42 to 0.51 mm/s., but for PDGF it is unchanged. The swimming speed of starved cells increases when the cells approach a solidified attractant (PP) as measured by the speed at a given distance. The speed of cells moving towards the attractant is higher than that of cells moving away from it. In conclusion, certain amino acids, peptides, and proteins are chemoattractants for Tetrahymena. Chemokinesis likely plays a considerable role in the case of PP (and YE), since they increase swimming speeds, whereas attraction by PDGF may involve chemotaxis.

Mycobacterium bovis bacillus Calmette-Gue´rin (BCG) has been used as a live bacterial vaccine to immunize more than 2 billion people against tuberculosis. In an attempt to use this vaccine strain as a vehicle for
protective antigens, the Plasmodium falciparum gene from strain FCC-1/HN encoding circumsporozoite protein (CSP) was amplified from the P. falciparum genome, sequenced, and expressed in M. bovis BCG under the
control of an expression cassette carrying the promoter of heat shock protein 70 (HSP70) from Mycobacterium tuberculosis. The recombinant shuttle plasmid pBCG/CSP was introduced into mycobacteria by electroporation, and the recombinant mycobacteria harboring pBCG/CSP could be induced by heating to express CSP; the molecular mass of recombinant CSP was about 42 kDa. This report of the expression of the almost-full-length P. falciparum CSP gene in BCG provides scientific evidence for the application of the HSP70 promoter in expressing a foreign gene in BCG and in the development of BCG as a multivalent vectoral vaccine for malaria.

The phylogeny of cyanobacteria is particularly interesting because of their ecological diversity and evolutionary importance Potts 2000, Shi and. The classification of cyanobacteria is traditionally based on morphological characters in both botanical and bacteriological systems . However, morphology does not necessarily reflect evolution in cyanobacteria, and molecular methods used during the last decades have improved cyanobacteria classification (Anagnostidis

ABSTRACT. In the last few years two factors have helped to significantly advance our understanding of the Myxozoa. First, the phenomenal increase in fin fish aquaculture in the 1990s has lead to the increased importance of these parasites; in turn this has lead to intensified research efforts, which have increased knowledge of the development, diagnosis, and pathogenesis of myxozoans. The hallmark discovery in the 1980s that the life cycle of Myxobolus cerebralis requires development of an actinosporean stage in the oligochaete, Tubifex tubifex, led to the elucidation of the life cycles of several other myxozoans. Also, the life cycle and taxonomy of the enigmatic PKX myxozoan has been resolved: it is the alternate stage of the unusual myxozoan, Tetracapsula bryosahnonae, from bryozoans. The 18S rDNA gene of many species has been sequenced, and here we add 22 new sequences to the data set. Phylogenetic analyses using all these sequences indicate that:l) the Myxozoa are closely relat...

Balamuthia mandrillaris is a protist pathogen that can cause encephalitis with a fatality rate of >95%. This is due to our incomplete understanding of the pathogenesis and pathophysiology of B. mandrillaris encephalitis. B. mandrillaris has two stages in its life cycle, an active trophozoite stage during which it divides mitotically. However, under unfavorable conditions, the trophozoite transforms into a dormant cyst stage. A major concern during the course of therapy is that B. mandrillaris can transform into cysts. Cysts are highly resistant to physical and chemical conditions and present a problem in successful antimicrobial chemotherapy. Several lines of evidence suggest that B. mandrillaris encephalitis develops as a result of hematogenous spread, but it is unclear how circulating amoebae enter the central nervous system and cause inflammation, blood-brain barrier disruption, and neuronal injury. Recent studies have identified several parasite-host determinants for B. mandrillaris translocation of the blood-brain barrier, and host inflammatory markers that may be associated with neuronal injury. These determinants may provide important targets for the prevention and treatment of this devastating infection. Here, we present a brief overview of the current understanding of the morphology, biology, pathogenesis, and pathophysiology of B. mandrillaris encephalitis.

Trypanosoma theileri infection, latent in a mature Hereford cow, could not be demonstrated in routine blood smears or cultures. Throughout the 2-year period an intravenous injection of dexamethasonc consistently produced parasitaemia which was detectable in peripheral blood mononuclear cell (PBMC) cultures. Fractionation techniques such as plastic adherence and Sephadex-G10 fractionation. designed to deplete monocytes and enrich T-lymphocytes, increased trypanosome-positive cultures from 25 to 100%. Removal of B-lymphocytes from Sephadex, non-adherent (SE-NA) cells did not reduce the percentage of positive cultures. Light and transmission electron microscopy of SE-NA PBMC cultured for 36 or 45 h revealed numerous trypanosomes and widespread T-lymphocyte destruction. No trypanosomes were observed in 12-h cultures. A close association, either extraor intracellular, of a parasitic stage of T. theiferi with T-lymphocytes is inferred.

SYNOPSIS. Extracts of Euglena gracilis carry out a very rapid but limited synthesis of phosphatidylcholine when S-adenosylmethionine or A T P and methionine are supplied. Cytidinediphosphocholine ap- CDP-choline, BSA and Tris buffer were obtained from Sigma Chemical Co.

AS more than half of all living organisms are parasites , most infections in nature consist of multiple parasite strains or species . Interactions among coinfecting parasites can strongly influence parasite dynamics (both within and among hosts) and host populations (

AS more than half of all living organisms are parasites , most infections in nature consist of multiple parasite strains or species . Interactions among coinfecting parasites can strongly influence parasite dynamics (both within and among hosts) and host populations (

ABSTRACTAs Plasmodium sporozoites undergo gliding motility in vitro, they leave behind trails of circumsporozoite (CS) protein that correspond to their patterns of movement. This light microscopic observation was made using Plasmodium berghei sporozoites, a monoclonal antibody (MAb H4) directed against the immunodominant repetitive epitope of the CS protein of P. berghei, and an immunogold‐silver staining (IGSS) technique. Sporozoites pretreated with agents that inhibit sporozoite motility and invasiveaess did not produce trails. Sporozoites that glided on microscope slides coated with MAb H4 left behind considerably longer CS prolem trails than those on uncoated slides, and the staining of these trails was more intense. The fact that the CS protein is an exoantigen continuously released as trails by motile sporozoites, together with our previous finding that anti‐CS protein antibodies inhibit sporozoite motility, strongly suggests that the CS protein plays a role in gliding motilit...

ABSTRACTWhen Paramecium calkinsi encounter hyperosmotic stress, intracellular free alanine increases. In vivo assays indicate that the reaction catalyzed by alanine aminotransferase contributes to the build up of alanine in response to hyperosmotic shock. 14C‐pyruvate is converted to 14C‐alanine in cells grown axenically at 200 mosm. When shifted to 600 mosm, the rate of conversion of pyruvate to alanine increases, and conversion at either 200 or 600 mosm is blocked by 1 mM aminooxyacetic acid (AOA), an inhibitor of aminotransferase. Intracellular free alanine increase is partially inhibited by AOA, and AOA prevents cells living in fresh water from acclimating to higher salinities, an indication that the increase in intracellular alanine is physiologically significant.

The exponential development of maritime transport has made ballast water a primary vector for the spread of invasive organisms across the aquatic realm. This research aims to present a comprehensive overview of methodological and bioinformatic considerations for eDNA metabarcoding applied to ballast water from ships in İzmit Gulf, northwest Türkiye, with an emphasis on non-native species. The data related to DNA sequences for COI, 18Sv8, 18Sv4, 16S, and 12S presented a broad diverse taxonomic group for both microbial and macroscopic species, even for rare ones, with numbers of 93, 191, 241, 19, and 44, respectively. Additionally, the research unveiled the presence of highly invasive species such as Rhopilema nomadica and identified their invasiveness risk for İzmit Gulf, primarily due to elevated water temperatures in relation to climate change. The outlined results indicate that metabarcoding offers a potential tool for early detection of nonindigenous species and implementing management plans in view of current global warming interactions.

This study characterizes microsporidian spores in the wasp Polistes sp. using light bright field microscopy and scanning electron microscopy (SEM). Initial observations with light microscopy revealed ovoid spores exhibiting brownian movement and high birefringence. SEM provided detailed insights, revealing heavy infestations in the gut lining and spores ovoid shape averaging 1.75 µm in length and 1.20 µm in width (N=5). Various life stages were observed: binary fission, merogony, sporogony, and germination. The SEM images also highlighted sophisticated infection mechanisms, including anchoring discs and polar tube extrusions. The resilience and transmission capabilities of mature spores were noted, along with active infection indicators such as germinated spores. These findings emphasize the importance of SEM in revealing the morphological characteristics of microsporidian spores and their interactions with Polistes wasp. The high-resolution images provided critical insights into spore adherence, proliferation, and developmental stages, enhancing the understanding of the ecological impacts and co-evolutionary dynamics of microsporidian infections in insect populations.

The site specificity of the apicomplexans Gregarina cuneata and Gregarina steini. in larval Tenebrio molitor was investigated. Gregarina cuneata was found to inhabit the anteriormost region ofthe larval midgut, while G. steini was restricted to the posterior portion of the intestine. The site specificity of the pair was conserved in single and mncurrent infections. Interspecific interactions do not seem to be presently responsible for the resoure partitioning by the 2 gregarine species.

Biological soil crusts are diverse assemblages of bacteria, cyanobacteria, algae, fungi, lichens, and mosses that cover much of arid land soils. The objective of this study was to quantify protozoa associated with biological soil crusts and test the response of protozoa to increased temperature and precipitation as is predicted by some global climate models. Protozoa were more abundant when associated with cyanobacteria/lichen crusts than with cyanobacteria crusts alone. Amoebae, flagellates, and ciliates originating from the Colorado Plateau desert (cool desert, primarily winter precipitation) declined 50-, 10-, and 100-fold, respectively, when moved in field mesocosms to the Chihuahuan Desert (hot desert, primarily summer rain). However, this was not observed in protozoa collected from the Chihuahuan Desert and moved to the Sonoran desert (hot desert, also summer rain, but warmer than Chihuahuan Desert). Protozoa in culture began to encyst at 37 1C. Cysts survived the upper end of daily temperatures (37-55 1C), and could be stimulated to excyst if temperatures were reduced to 15 1C or lower. Results from this study suggest that cool desert protozoa are influenced negatively by increased summer precipitation during excessive summer temperatures, and that desert protozoa may be adapted to a specific desert's temperature and precipitation regime.

Biological soil crusts are diverse assemblages of bacteria, cyanobacteria, algae, fungi, lichens, and mosses that cover much of arid land soils. The objective of this study was to quantify protozoa associated with biological soil crusts and test the response of protozoa to increased temperature and precipitation as is predicted by some global climate models. Protozoa were more abundant when associated with cyanobacteria/lichen crusts than with cyanobacteria crusts alone. Amoebae, flagellates, and ciliates originating from the Colorado Plateau desert (cool desert, primarily winter precipitation) declined 50-, 10-, and 100-fold, respectively, when moved in field mesocosms to the Chihuahuan Desert (hot desert, primarily summer rain). However, this was not observed in protozoa collected from the Chihuahuan Desert and moved to the Sonoran desert (hot desert, also summer rain, but warmer than Chihuahuan Desert). Protozoa in culture began to encyst at 37 1C. Cysts survived the upper end of daily temperatures (37-55 1C), and could be stimulated to excyst if temperatures were reduced to 15 1C or lower. Results from this study suggest that cool desert protozoa are influenced negatively by increased summer precipitation during excessive summer temperatures, and that desert protozoa may be adapted to a specific desert's temperature and precipitation regime.

Mitochondrial genome sequence of Vannella croatica (Amoebozoa, Discosea, Vannellida) was obtained using pulse-field gel electrophoretic isolation of the circular mitochondrial DNA, followed by the next-generation sequencing. The mitochondrial DNA of this species has the length of 28,933 bp and contains 12 protein-coding genes, two ribosomal RNAs, and 16 transfer RNAs. Vannella croatica mitochondrial genome is relatively short compared to other known amoebozoan mitochondrial genomes but is rather gene-rich and contains significant number of open reading frames.

The planktonic ciliates in the Romanian Black Sea waters have been little studied, although they have high ecological significance in the matter and energy flow of pelagic ecosystems. Among other common zooplankters, the protozoan Laboea strobila was identified for the first time in the shallowwater area of the Romanian continental shelf in the spring of 2011. In the paper, the author presents data on the morphometry and distribution of this recently reported protozoan in the Black Sea.

An important feature of ruminal ciliates is their phenotypic plasticity, which makes their identification difficult. The common manifestation of the phenotypic plasticity in rumen ciliates is a change in their cell size and caudal spination. We analyzed various morphotypes of Epidinium with five caudal processes (spines) taken from the rumen of European bison (Bison bonasus). In the study, the cluster analysis and K-means analysis of morphometric data could not distinguish very similar morphotypes of Epidinium with five caudal processes. However, the morphotype of E. parvicaudatum prevailed (70%). The DNA of four individual E. parvicaudatum was isolated successfully from formaldehyde-preserved samples. The partial 18S rDNA gene sequences (about 350-400 bp) were identical to Epidinium sequences in GenBank (E. caudatum, a one-spine morphotype, and E. cattanei, a five-spine morphotype). It can be assumed that these short sequences cannot distinguish the differences between the Epidinium morphospecies. Complete gene sequences from various hosts and various molecular markers are necessary to reveal the validity of the Epidinium five-spine species. In conclusion, classical morphology should be supplemented with molecular data when more morphotypes of the rumen ciliate species are present in samples.

This study aims to perform population analysis of the rumen ciliated protozoa of the
free-living European bison (wisent, Bison bonasus, Linnaeus). The samples of the
rumen fluid from the 18 bison subjected to the controlled culls within the free-ranging
population in the Bialowieza primeval forest in Poland were collected and examined.
The examined ciliates population consisted of the species of the families Isotrichidae
and Ophryoscolecidae. There were 12 genera (Isotricha, Dasytricha, Diplodinium,
Elytroplastron, Entodinium, Eodinium, Epidinium, Eremoplastron, Eudiplodinium,
Metadinium, Ophryoscolex, and Ostracodinium) and 32 morphospecies of the ciliates.
We observed the prevalence of a type B protozoan population (56% animals) with
the typical Epidinium and Eudiplodinium genera members. Other examined animals
possessed the mixed A–B population with Ophryoscolex genus, distinct for type A ciliate
population. The average total ciliates count was 2.77 ± 1.03 × 105/ml (mean ± SD). The
most abundant genera were Entodinium, 83%, and Dasytricha, 14%. The abundance of
other genera was <1% of the total count. Within the 16 Entodinium species determined,
the most abundant species was Entodinium nanellum (16.3% of total ciliates count).
The average Shannon–Wiener diversity index was 2.1 ± 0.39, evenness was 0.7 ±
0.11, and species richness was 24 ± 3.0 (mean ± SD). Our study is the first report
on the population composition and diversity of rumen ciliates of European bison. The
composition and counts of ciliate genera and species were similar to the composition
and counts of the rumen ciliated protozoa of American bison and many other kinds of
free-living and domestic ruminants. Our European bison ciliate population analysis has
shown medium ciliate density and high diversity typical for large free-living ruminants
with mixed feeding behavior.

Background Leishmaniasis, caused by parasites of the genus Leishmania, is a disease that effects up to 8 million people worldwide. Parasites are transmitted to human and animal hosts through the bite of an infected sand y. Novel strategies for disease control, require a better understanding of the key step for transmission namely, the establishment of infection inside the y. Methods In this work we wanted to identify y transcriptomic signatures associated with infected blood meal with non-infected blood meal as our baseline. We used next generation sequencing to describe the transcriptome of the sand y Phlebotomus papatasi when fed with blood alone or with blood containing one of three trypanosomatids: Leishmania major, Leishmania donovani and Herpetomonas muscarum: a parasite not transmitted to humans. Results Of these, only L. major was able to successfully establish an infection in P. papatasi. However, the transcriptional signatures observed were not speci c to success or failure of infection but a generalised response to the blood meal. Conclusions This implies that sand ies perceive Leishmania as just one feature of their microbiome landscape and that any strategy to tackle transmission should focus on the response towards the blood meal rather than parasite establishment. This result will generate new thinking around the concept of stopping transmission by controlling the parasite inside the insect.

Soil from a roadside ditch at Lake Waccamaw. North Carolina. was tested for cyst-forming free-living amoebae, and water from the same ditch was tested for fecal coliform bacteria. Soil saniples incubated at room temperature (21-23" C) yielded Acanthunioeba polyplrcrgcr, Amoeba sp.. H\.peranroeba sp., M(ryorrl1ir prtiardi. Nac,gleria gruberi, Naeglerici minor, and unidentified ciliates, testaceans and slime molds. Incubation at 37-39" C yielded Acanrhanioeba jrrcobsi. Plafynmorba schaejferi, and a new amoeba to be described herein. Fecal contamination of the ditch was confirmed by a direct membrane filtration technique that yielded a mean of 1.410 i 134 bacteria/ ml. The new. amoeba is assigned to the class Heterolobosea Page & Blanton. 1985 on the basis of promitotic nuclear division. and a flagellated stage with a cytostome as seen in the genus Trtramifus. Amoebae studied in hanging drop preparations were flattened and irregular as described for the genus S?~rchyirrnoebtz in the family Gruberellidae but changed to a lobose cylindrical form as described for species of L'dilkcimpfia in the family Vahlkanipfiidae. A new genus and species, Leuramorba ~~crcc.arrrn~~m.si.s. is proposed for the amoeba described herein.

Cancer pagurus (Cancridae) from the Atlantic coast of France is parasitized by a new species of microsporida Ameson atlantieuin sp. nov. The main stages of the life eyele of the parasite are a monokaryotic and then diplokaryotic meront. tetranucleate (at least) sporont (sporogonial sporont), uninucieate sporoblast and spore. The spore (1-9x1 5 ixm) possesses 11-12 coils of the polar filament and a lamellar polaroplast. Hairlike appendages are present on the surface of the sporoblastic plasmodium, sporoblast and spore. All stages take place in direct contact with the muscular tissue of the crab. Infection provokes the destruetion of 80% of host musele myofibrils.

With the use of Weber's modified trichrome and Uvitex 2B techniques, spores of microsporidia were detected in the stools of four travelers presenting clinically with chronic diarrhea. The general health of these patients was not impaired, and human immunodeficiency virus screening was negative. Immune evaluation, including the study of lymphocytic subpopulations, assay of serum immunoglobulins, and an intradermal multitest, showed normal results. Molecular identification of microsporidian species was based on the PCR amplification of a small-subunit rRNA sequence followed by HinfI endonuclease restriction. Encephalitozoon intestinalis microsporidiosis was thus shown in two of the four patients examined. In two patients, therapy based on albendazole made stools devoid of microsporidian spores without influence on the intestinal disorders. The pathogenic role of E. intestinalis in immunocompetent individuals remains to be demonstrated.

Mtrrteilitl rrfringrns is recognized as one of the most significant pathogens of bivalve molluscs. The nucleotide sequence of the small subunit ribosomal RNA gene of Murteilia refringens is used to elucidate the phylogenetic position of the phylum Paramyxea. Genoniic DNA was extracted from sporangia of Marreilia, purified from infected blue mussels, Mytilus edulis. and flat oysters, O.rrrru c,clulis. The sequences obtained from Mtrrtei[iu species purified from both oysters and mussels were identical. The sequence identity was confirmed by in situ hybridization using a DNA probe targeted to a variable region of the ribosomal DNA. The small subunit ribosomal RNA gene sequence of M. rq5ringen.s is very different from all known sequences of eukaryotic organisms, including those of myxosporeans and haplosporeans. Therefore, the phylum Paramyxea should continue to be recognized as an independent eukaryotic phylum.

Ultrastruotural study of Thelohania maenadis PEREZ, miorosporidian parasite of the orabs Garoinu8 mediterraneUB CZERNIAVSKY and G. maenGS L. has been st udied again. The whole lifecyole of a speoies of the genus Thelohania HENNE GUY is described: uninucleate sporoplasm, uniafterwards diplokaryotic meront, diplokaryotic sporont, uninucleate sporohlaste and spore. Pansporobiastic tubular structures are different from exosporous filaments and their funotion is discussed. W e emphasize on the originality of the polar filament formation in t wo phases: so, each row is made by golgian secretions of two different types; the polar filament diffe renoiation is later than that of exosporous filaments but earlier than that of sporoblastic isolation. The sporogoniai plasmodium may be an essential character of the genus Thelohania.

This revision of the classification of unicellular eukaryotes updates that of for the protozoa and expands it to include other protists. Whereas the previous revision was primarily to incorporate the results of ultrastructural studies, this revision incorporates results from both ultrastructural research since 1980 and molecular phylogenetic studies. We propose a scheme that is based on nameless ranked systematics. The vocabulary of the taxonomy is updated, particularly to clarify the naming of groups that have been repositioned. We recognize six clusters of eukaryotes that may represent the basic groupings similar to traditional ''kingdoms.'' The multicellular lineages emerged from within monophyletic protist lineages: animals and fungi from Opisthokonta, plants from Archaeplastida, and brown algae from Stramenopiles.

Euglena gracilis is able to synthesize adenosine triphosphate under anaerobic conditions through a malonyl-independent fatty acid synthesis leading to wax ester fermentation. Mitochondrial fatty acid synthesis uses acetyl-CoA and propionyl-CoA as C2-and C3-donors for de novo synthesis of even-and odd-numbered fatty acids, respectively. Euglena's wax ester fermentation has only been described in the E. gracilis strain 1224-5/25 Z. Here we investigate eight E. gracilis strains isolated in 1932-1958 from different localities in Europe and two bleached substrains of E. gracilis 1224-5/25, obtained by treatment with streptomycin and ofloxacin, and examine their anaerobic growth, wax ester fermentation, and wax ester composition. Under ambient oxygen levels, all strains accumulated wax esters in concentrations between 0.3% and 3.5% of the dry weight, but the strains revealed marked differences in wax ester accumulation with respect to anaerobic growth. Most fermenting strains tested showed increased wax ester synthesis under anaerobic conditions as well as the increased synthesis of odd-numbered fatty acids and alcohols suggesting an activation of the mitochondrial fatty acid biosynthesis pathway. Addition of the elongase inhibitor flufenacet to the growth medium specifically reduced the accumulation of odd-numbered fatty acids and alcohols and tended to increase the overall yield of anaerobic wax esters. Key Words. Fatty acid methyl esters (FAMEs), fatty alcohols (FAlcs), gas chromatography (GC).

The present study analyzes the e€ects of zinc on Entamoeba histolytica activity and on its pathogenicity. Metal activity was evaluated in vitro with regard to the parasite&#39;s viability, replication, and adhesion to epithelial cells and in vivo with regard to its pathogenicity. The results obtained in vitro show that zinc at 1.0 mM concentration does not a€ect amebic viability; however, it does decrease amebic replication and adhesion (P &lt; 0.001). In vivo studies performed on a model of experimental liver abscess in the hamster indicate that the intraperitoneal administration of a single dose of zinc at 48 h after the intrahepatic inoculation of amebic trophozoites signi®cantly inhibits (P &lt; 0.001) abscess development. The results indicate that zinc alters the functionality of the ameba in vitro as re ̄ected by a decrease in replication and adhesion and in vivo as manifested by inhibition of amebic pathogenicity.

ABSTRACT. Using the polymerase chain reaction and arbitrarily selected oligonucleotide primers of 10 or 11 bases, we have amplified DNA sequences from Trypanosoma vivax parasites isolated from South America and Africa. On the basis of polymorphisms in the DNA fingerprints generated by three of the primers, the parasites could be separated into two major groups, one comprising T. vivax isolates from Kenya and the second including all the other T. vivax parasites (from Colombia, The Gambia, Nigeria and Uganda). One of these three primers (ILo 525) also gave isolate‐specific DNA fingerprints for the parasites for the parasites tested, which will allow the use of this technique both in the species identification and discrimination of T. vivax parasites.