Phylogenetic relationships among isolates of Cryptosporidium: evidence for several new species

Isolates of Cryptosporidium were characterized using nucleotide sequence analysis of the 18S rRNA and dihydrofolate reductase genes and also random-amplified polymorphic DNA analysis. Phylogenetic analysis confirmed the validity of the species of Cryptosporidium examined in this study such as Cryptospordium muris and Cryptosporidium baileyi, and also reinforced evidence from numerous researchers worldwide suggesting that Cryptosporidium parvum is not a single uniform species. The data obtained provided strong support for the validity of Cryptosporidium felis. Evidence suggests that the newly identified marsupial and pig genotypes may also be distinct and valid species, but biological studies are required for confirmation.     

Cryptosporidium andersoni is the predominant species in post-weaned and adult dairy cattle in China

Dairy industry plays an important role in the agricultural economy of China. To estimate the prevalence and public health significance of cryptosporidiosis in post-weaned and adult dairy cattle in China, during four consecutive years (from 2006 to 2009), a total of 1315 fecal samples from 22 dairy cattle farms in ten prefectures in Henan Province were examined for the presence of Cryptosporidium oocysts. The overall prevalence of Cryptosporidium was 7.9%, with the highest infection rate (11.3%) in 3 to 11-month-old calves and the lowest infection rate (1.0%) in >2-year-old cows (p<0.01). Cryptosporidium-positive samples (n=104) were analyzed by PCR-restriction fragment length polymorphism (RFLP) analysis of the small subunit (SSU) rRNA gene, and 25 representative samples were further analyzed by DNA sequencing of the PCR products. Cryptosporidium bovis and Cryptosporidium andersoni were identified. C. andersoni (84/104) was the predominant species and was found in all age groups, whereas C. bovis (20/104) was only detected in 3 to 11-month-old calves. Thus, C. andersoni appears to be the dominant species in weaned dairy calves and heifers in China, in contrast with its common occurrence in adult cattle in other parts of the world.     

Back in time: a new systematic proposal for the Bilateria

Conventional wisdom suggests that bilateral organisms arose from ancestors that were radially, rather than bilaterally, symmetrical and, therefore, had a single body axis and no mesoderm. The two main hypotheses on how this transformation took place consider either a simple organism akin to the planula larva of extant cnidarians or the acoel Platyhelminthes (planuloid-acoeloid theory), or a rather complex organism bearing several or most features of advanced coelomate bilaterians (archicoelomate theory). We report phylogenetic analyses of bilaterian metazoans using quantitative (ribosomal, nuclear and expressed sequence tag sequences) and qualitative (HOX cluster genes and microRNA sets) markers. The phylogenetic trees obtained corroborate the position of acoel and nemertodermatid flatworms as the earliest branching extant members of the Bilateria. Moreover, some acoelomate and pseudocoelomate clades appear as early branching lophotrochozoans and deuterostomes. These results strengthen the view that stem bilaterians were small, acoelomate/pseudocoelomate, benthic organisms derived from planuloid-like organisms. Because morphological and recent gene expression data suggest that cnidarians are actually bilateral, the origin of the last common bilaterian ancestor has to be put back in time earlier than the cnidarian-bilaterian split in the form of a planuloid animal. A new systematic scheme for the Bilateria that includes the Cnidaria is suggested and its main implications discussed.     

Occurrence of Cryptosporidium andersoni in Brazilian cattle

Feces were collected from 68 dairy cattle, 1 to 12 mo of age, on 12 farms in the municipality of Campos dos Goytacazes, Rio de Janeiro, Brazil, and examined for the presence of Cryptosporidium sp. All samples were subjected to molecular analysis by polymerase chain reaction (nested PCR) of the 18S rRNA. Four positive samples (4.54%) were sequenced and identified as Cryptosporidium andersoni. This species represents a risk for Brazilian cattle because infection can affect cattle productivity. Moreover, C. andersoni is considered a zoonotic species.     

Westerdykella globosa,a proposal for a new combination

The surface ornamentation of ascospores ofPreussia globosa was compared in an isolate from paddy soil in Japan and a culture derived from the holotype. The ascospores of two cultures were characterized by the surface ornamentation of a single, semicircular spiral ridge. This new finding strongly suggested that the fungus should be transferred to the genusWesterdykella. Therefore, the morphological and cultural characters of the fungus were re-examined, and the new combinationWesterdykella globosa is herein proposed.     

ITS2 sequences of Dictyocaulus species from cattle, roe deer and moose in Sweden: molecular evidence for a new species.

Total DNA was isolated from adult lungworms of the genus Dictyocaulus, collected from cattle, moose (Alces alces) and roe deer (Capreolus capreolus) in Sweden. The second ribosomal internal transcribed spacer was amplified with PCR, and DNA sequences were determined from nine individual worms that all came from different hosts in order to avoid analysis of siblings. The sequence data obtained were aligned and compared with similar data derived from German lungworm isolates from cattle and fallow deer (Cervus dama). These analyses clearly showed that specimens of the cattle lungworm, Dictyocaulus viviparus, were almost identical irrespective of their geographical origin. However, when the second internal transcribed spacer sequence of D. viviparus was compared with that of lungworms from moose and roe deer, major differences were noticed. Although lungworms collected from these cervids had identical second internal transcribed spacer sequences, they proved to be genetically different from Dictyocaulus eckerti of German fallow deer, displaying a 66.5% similarity. In an evolutionary tree, inferred by maximum likelihood analysis, the Dictyocaulus species from cattle and wild cervids clustered as compared with Dictyocaulus filaria from sheep. The study has thus demonstrated that A. alces and C. capreolus in Sweden are parasitised with a Dictyocaulus species that is different from D. viviparus and D. eckerti, indicating that we are dealing with a new species in moose and roe deer.     

A new species of Lamproderma (Myxomycetes) found in Java

A new species, Lamproderma retkulospomm , is described from Java. It is characterized by small sporangia, peridium with smooth, elevated patches, capillitium with numerous swellings, and completely banded-reticulate spores.     

Naegleria lovaniensis new species: Isolation and identification of six thermophilic strains of a new species found in association with Naegleria fowleri

Six Naegleria strains, isolated previously in association with N. fowleri from thermal waters, were studied to further determine their antigenic relationship to N. fowleri and other Naegleria species. Results of immunofluorescent antibody and immunoelectrophoretic studies clearly established the antigenic divergence of the variants from N. fowleri, N. gruberi, and N. jadini. The variants were further distinguished from known Naegleria species by several ultrastructural characteristics, which included the complete enclosure of their nuclei with one or several layers of rough endoplasmic reticulum (RER) and extrusion of their nuclear material. Extruded nuclear material was observed in the cytoplasm completely sequestered by cisternae of the RER. The variants were also shown to be sensitive to agglutination induced by concanavalin A but not by wheat germ agglutinin. Based on the differences in the antigenicity, morphology, and lectin sensitivity between these six variants and established Naegleria species, we proposed that they should be established as a new species.     

Nuclear transfer: a new tool for reproductive biotechnology in cattle

Recent evolutions of somatic cloning by nuclear transfer are reported, especially in the bovine species where potential applications are underway for biomedicine in association with transgenesis, or for agriculture by improving livestock. The overall efficiency of this biotechnology remains low in terms of viable offspring, but significant progress has been achieved on the different steps of the technique. However, the in vivo development of bovine blastocysts derived from somatic nuclear transfer is characterised by some important features that lead to the "cloning syndrome". Important losses occur during the peri-implantation period and further late foetal loss is observed in association with the Large Offspring Syndrome. About 60-70% of the cloned calves born survive normally to the adult stage and present an apparently normal physiology. Recent data already available on bovine somatic clones of both sexes indicate that they have a zootechnical performance similar to non cloned animals and they are able to reproduce normally without the pathologies associated to cloning thus confirming that the deviations observed in clones are of epigenetic origin and not transmitted to the progeny.     

Morphology is not a reliable tool for delineating species within Cryptosporidium

Within the coccidia, morphological features of the oocyst stage at the light microscope level have been used more than any other single characteristic to designate genus and species. The aim of this study was to conduct morphometric analysis on a range of Cryptosporidium spp. isolates and to compare morphological data between several genotypes of C. parvum and a second species C. canis, as well as a variation within a specific genotype (the human genotype), with genetic data at 2 unlinked loci (18S ribonucleic deoxyribonucleic acid and HSP 70) to evaluate the usefulness of morphometric data in delineating species within Cryptosporidium. Results indicate that morphology could not differentiate between oocysts from C. parvum genotypes and oocysts from C. canis, whereas genetic analysis clearly differentiated between the two. The small size of the Cryptosporidium spp. oocyst, combined with the very limited characters for analysis, suggests that more reliance should be placed on genetic differences, combined with biological variation, when delineating species within Cryptosporidium.     

Molluscs and biodegradable pollution in rivers: proposal for a scale of sensitivity of species

Malacological surveys and physico-shemical water analysis have been carried out at one hundred and sixty stations in France, distributed accross five major catchment areas. The relationships between six of the variables: dissolved oxygen, BOD₅, ammonia nitrogen, nitrites, Kjeldhal nitrogen and orthophosphates can be considered as indicators of biodegradable pollution and the populations of forty eight species of molluscs have been studied using correspondence analysis. A scale of sensitivity of these to this type of pollution is presented.     

Cryptococcus stepposus,a new filobasidiaceous yeast species found in the Prioksko-terrasny biosphere reserve in Russia

Mycocinotyping of cryptococci from the Prioksko-terrasny reserve (Russia) has revealed three strains that have a unique mycocin-sensitivity profile. Sequencing results of the D1/D2 domain of the 26S rDNA and of the complete ITS region placed them in the Floriforme clade of the Filobasidiales lineage (Hymenomycetes). The three strains had identical sequences, which differed from those of known Filobasidium and Cryptococcus species. A novel species named Cryptococcus stepposus (type strain VKM Y-2918) is proposed to accommodate these isolates. Physiological characteristics distinguishing the novel species from other Cryptococcus species in the Floriforme clade are presented.