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In recent years, Tetrahymena species have been used as model organisms for research in a wide range of fields, highlighting the need for a fuller understanding of the taxonomy of this group. It is in this context that this paper uses living observation and silver staining methods to investigate the morphology and infraciliature of one Tetrahymena species, T. setosa (Schewiakoff 1892 Verh. Naturh. Med. Ver. Heidelb., 4:544) McCoy (1975) Acta Protozool., 14:253; the senior subjective synonym of T. setifera Holz and Corliss (1956) J. Protozool., 3:112; isolated from a freshwater pond in Harbin, north‐eastern China. This organism can be distinguished from other described Tetrahymena species mainly by its single caudal cilium, which is about twice the length of the somatic ciliature. While the Harbin isolate appears similar to the population described by Holz and Corliss (1956) J. Protozool., 3:112, an improved diagnosis for T. setosa is given based on the previous descriptions and the Harbin population. In summary, this species can be recognized mainly by the combination of the following characters: body in vivo approximately 40 μm × 25 μm, 21–26 somatic kineties, one to four contractile vacuole pores associated with meridians 6–11 and a single caudal cilium. The small subunit ribosomal (SSU) rRNA gene and the cox1 gene sequences of Harbin population are also characterized in order to corroborate that the isolated species branches in phylogenetic trees as a T. setosa species. The phylogenetic analysis also indicated that sequences of populations of Tetrahymena species should be published with detailed morphological identifications. [ABSTRACT FROM AUTHOR]

ABSTRACT Acanthamoeba genus is divided into 20 genotypes (T1-T20) on the basis of the gene encoding 18S rRNA sequence. Using of at least 2 kbp gene fragments is strongly recommended to identify new genotypes and 5% difference is commonly used as a criterion of new genotypes, however, this value is questionable. In this paper, Polish Acanthamoeba strains described earlier on the basis of ~850 bp Ami fragment of 18S rRNA gene as T4, T11 and a new T16 genotype, have been analyzed using near-complete sequence of the gene. This analysis was needed because the Ami fragment does not reveal full variability within 18S rRNA gene. Phylogenetic analysis based on Ami fragment is biased by artifacts in the construction of the tree, so the fragment should not be used for identification of new putative Acanthamoeba genotypes. The analysis confirmed that the Polish sequences represent T4 and T11 genotypes and that the strains described earlier as T16 genotype are in fact a new subgroup of the T20 genotype and that this genotype should be divided into two subgroups: T20a (two strains described by [ J. Eukaryot. Microbiol. 62 (2015) 69]) and T20b (11 Polish strains described in this study). The T20b subgroup was isolated from both clinical samples and water bodies used by people as bathing places and there is a risk of infection for humans during contact with water. [ABSTRACT FROM AUTHOR]

Presents the abstracts of papers presented in the annual meetings of associations of protozoologists in 2004.

Presents several abstracts of papers submitted at the Czech Section Society of Protozoologists 33rd Annual Meeting. "The Development of a Precious Strain of Eimeria Necatrix," by M. Hortvíková; "Distribution of Ciliates of Different Feeding Specializations in the Water Bodies of Different Trophy," by M. Macek, K. Simek and A. L. Vasquez; "Methods of Analysis and 3D Imaging of Protozoan Cytoloskeletal Structures Obtained by Confocal Microscopy," by J. Novy, J. Tomas and R. Janisch; "Selection and Characterization of a Precious Line of Rabbit Coccidium Eimeria Flavescen," by M. Pakandl, F. Cerník and Z. Houdek.