Morphology and molecular phylogeny of a new hypotrich ciliate, Anteholosticha songi nov. spec., and an American population of Holosticha pullaster (Müller, 1773) Foissner et al., 1991 (Ciliophora, Hypotrichia).

A new urostylid ciliate, Anteholosticha songi nov. spec., isolated from forest soil in Tibet, and an American population of Holosticha pullaster (Müller, 1773) Foissner et al., 1991, isolated from a freshwater pond in the USA, are investigated in terms of their morphology, ontogenesis, and molecular biology. Anteholosticha songi nov. spec. is characterized by a slender to ellipsoidal body measuring 160-205 × 40-55 µm in vivo; rod-shaped yellowish cortical granules arranged in irregular short rows; four dorsal kineties; adoral zone consisting of 35-40 membranelles; three frontal, one buccal, one parabuccal, two frontoterminal, two pretransverse, and four to six transverse cirri and 14-25 midventral pairs; 12-22 ellipsoidal macronuclear nodules longitudinally arranged in pairs left of cell mid-line. Supplemental information on morphogenesis in Holosticha pullaster is also presented. The phylogenetic relationship of Anteholosticha and Holosticha inferred from SSU rDNA sequence data are concordant with previous studies and showing that Holosticha is monophyletic whereas Anteholosticha is polyphyletic and should be split into two or more genera.

Evaluation of Occurrence, Concentration, and Removal of Pathogenic Parasites and Fecal Coliforms in Three Waste Stabilization Pond Systems in Tanzania.

In Tanzania, waste stabilization ponds (WSPs) are employed to treat wastewater, and effluents are used for urban agricultural activities. The use of untreated or partially treated wastewater poses risks of disease transmission, including parasitic and bacterial infections, to exposed communities. Little is known about the occurrence, concentration, and removal of parasites and fecal coliform (FC) bacteria in WSPs in Tanzania. This study evaluates the occurrence and concentration of parasites and FCs in wastewater, the efficiency of WSPs in removing parasites and FCs, and the validity of using FCs as an indicator of parasites. This was a cross-sectional study conducted between February and August 2018. Wastewater samples were collected from three WSPs located in the Morogoro, Mwanza, and Iringa regions. APHA methods were used to test physicochemical parameters. The modified Bailenger method and Ziehl-Neelsen stain were used to analyse parasites. Membrane filtration method was used to analyse FCs. Data were analysed using IBM SPSS version 20. Helminth egg removal ranged from 80.8% to 100%. Protozoan (oo)cyst removal ranged from 98.8% to 99.9%. The Mwanza WSP showed the highest FC reduction (3.8 log units (100 mL)-1). Both the parasites and FCs detected in the effluents of assessed WSPs were of higher concentrations than World Health Organization and Tanzania Bureau of Standards limits, except for helminths in the Morogoro WSP and FCs in the Mwanza WSP. FCs were significantly correlated with protozoa (p < 0.01) and predicted protozoa occurrence well (p=0.011). There were correlations between physicochemical parameters, parasites, and FC bacteria in the WSP systems. Inadequate performance of these systems may be due to lack of regular maintenance and/or systems operating beyond their capacity. FC indicators were observed to be a good alternative for protozoa monitoring, but not for helminths. Therefore, during wastewater quality monitoring, helminths should be surveyed independently.

Studies on Woloszynskioid Dinoflagellates X: Ultrastructure, Phylogeny and Colour Variation in Tovellia rubescens n. sp. (Dinophyceae).

The external morphology and internal cell fine structure of a new species of Tovelliaceae, Tovellia rubescens n. sp., is described. Phylogenetic analyses based on partial LSU rDNA sequences place the new species in a clade containing Tovellia species that accumulate red pigments and identify T. aveirensis as its closest known relative. Cells of T. rubescens n. sp. were mostly round and had the cingulum located near the middle, with its ends displaced about one cingular width. Small numbers of distinctly flat cells appeared in culture batches; their significance could not be determined. Cells of the new species in culture batches progressively changed from a yellowish-green, mainly due to chloroplast colour, to a reddish-brown colour that appeared associated with lipid bodies. The switch to a reddish colour happened earlier in batches grown in medium lacking sources of N or P. Pigment analyses by HPLC-MS/MS revealed the presence of astaxanthin and astaxanthin-related metabolites in the new species, but also in T. aveirensis, in which a reddish colour was never observed. The chloroplast arrangement of T. rubescens n. sp. resembled that of T. aveirensis, with lobes radiating from a central pyrenoid complex. The flagellar apparatus and pusular system fell within the general features described from other Tovelliaceae. A row of microtubules interpretable as a microtubular strand of the peduncle was present. Spiny resting cysts with red contents and an ITS sequence identical to that of cultured material of the new species were found in the original locality.

Accumulation and exchange of parasites during adaptive radiation in an ancient lake.

In the ancient Lake Baikal, Russia, amphipod crustaceans have undergone a spectacular adaptive radiation, resulting in a diverse community of species. A survey of microsporidian parasites inhabiting endemic and non-endemic amphipod host species at the margins of Lake Baikal indicates that the endemic amphipods harbour many microsporidian parasite groups associated with amphipods elsewhere in Eurasia. While these parasites may have undergone a degree of adaptive radiation within the lake, there is little evidence of host specificity. Furthermore, a lack of reciprocal monophyly indicates that exchanges of microsporidia between Baikalian and non-Baikalian hosts have occurred frequently in the past and may be ongoing. Conversely, limitations to parasite exchange between Baikalian and non-Baikalian host populations at the margins of the lake are implied by differences in parasite prevalence and lack of shared microsporidian haplotypes between the two host communities. While amphipod hosts have speciated sympatrically within Lake Baikal, the parasites appear instead to have accumulated, moving into the lake from external amphipod populations on multiple occasions to exploit the large and diverse community of endemic amphipods in Lake Baikal.

Survey of the Occurrence and Human Infective Potential of Giardia duodenalis and Cryptosporidium spp. in Wastewater and Different Surface Water Sources of Western Romania.

From the group of parasitic protozoa, Giardia and Cryptosporidium are the most common pathogens spread in surface water sources, representing a continuous threat to public health and water authorities. The aim of this survey was to assess the occurrence and human infective potential of these pathogens in treated wastewaters and different surface water sources. A total of 76 western Romanian water bodies in four counties (Arad, Bihor, Caraș-Severin and Timiș) were investigated, including the effluents of wastewater treatment plants (n = 11) and brooks (n = 19), irrigation channels (n = 8), lakes (n = 16), and ponds (n = 22). Water samples were collected through polyester microfiber filtration. Giardia cysts and Cryptosporidium oocysts were isolated using immunomagnetic separation, according to the US EPA 1623 method, followed by their identification and counting by immunofluorescence (IF) microscopy. All samples were screened through PCR-based techniques targeting the gdh gene for Giardia spp. and the 18S rRNA gene for Cryptosporidium spp., followed by sequencing of the positive results. Cryptosporidium-positive samples were subtyped based on sequence analysis of the GP60 gene. Giardia spp. was found in all tested water types with a cumulative detection rate of 90.1% in wastewaters, 26.3% in brooks, 37.5% in irrigation channels, 31.2% in lakes, and 36.4% in ponds. Except for ponds, all monitored water bodies harbored the Giardia duodenalis AII subassemblage with human infective potential. In addition, the ruminant origin assemblage E was widely distributed, and the domestic/wild canid-specific assemblage D was also recorded in a pond. Three (27.3%) wastewater samples were Cryptosporidium positive, and the identified species was the zoonotic Cryptosporidium parvum, with IIaA15G2R1 (n = 2) and IIdA18G1 subtypes. The results highlight that this threat to the public health must be brought to the attention of epidemiologists, health officials, and water authorities.

A New Heterolobosean Amoeboflagellate, Tetramitus dokdoensis n. sp., Isolated from a Freshwater Pond on Dokdo Island in the East Sea, Korea.

The genus Tetramitus is a representative amoeboflagellate group within the Heterolobosea, and currently contains over a dozen species. Here, a new heterolobosean amoeboflagellate was isolated from a freshwater pond on Dokdo Island, Korea. The amoebae have eruptive pseudopodia, no uroidal filament, and a nucleus with a central nucleolus. The length and width of the amoebae are 15.5-28.0 µm and 5.4-12.6 µm, respectively. The flagellates are conical, with 4 flagella of equal length (~10 µm). There is a discrete rostrum in the subapical region of the flagellate form. The cyst has thin endo- and ectocyst layers and no cyst pores. The amoeba shows slow movement at 37 °C, but does not move at 42 °C under a light microscope. Phylogenies of the 18S rRNA gene and the ITS1-5.8S rRNA gene-ITS2 sequence show that the strain belongs to a subclade of Tetramitus that includes Tetramitus rostratus, Tetramitus waccamawensis and Tetramitus entericus, amongst others. Nonetheless, the strain is distinct from other species in both molecular phylogenetic trees. Thus the strain isolated from the Dokdo Island is proposed as a novel species, Tetramitus dokdoensis n. sp.

Identification of Acanthamoeba Genotypes in Pools and Stagnant Water in Ponds in Sistan Region in Southeast Iran.

OBJECTIVE: Acanthamoeba is one of the most abundant free-living amoebas that is widely distributed in natural and artificial environment resources. Acanthamoeba pathogenic genotypes cause chronic human diseases including amoebic keratitis and granulomatous amoebic encephalitis. The aim of this study was to determine and identify Acanthamoeba genotypes residing in pools and stagnant water in ponds in Sistan region in southeast Iran. This descriptive study was conducted at the Parasitology Laboratory, School of Medicine, Zabol University of Medical Sciences. METHODS: In this descriptive study, 93 water samples were collected from pools and ponds in Zabol, Zahak, Hirmand, Hamoon, and Nimrooz in Sistan region. Samples after filtering through 0.45-µm nitrocellulose paper filters were cultured in a 1.5% non-nutrient agar medium enriched with heat-killed Escherichia coli. Polymerase chain reaction (PCR) was conducted using specialized primers for detecting the genus Acanthamoeba. The sequencing of positive samples was used for determining Acanthamoeba genotypes. RESULTS: From 82 free-living amoeba positive culture samples, 38 isolates were confirmed to belong to the genus Acanthamoeba by PCR. On sequencing, 34 samples (89.47%) belonged to the T4 genotype, three (7.9%) to the T5 genotype, and one (2.63%) to the T3 genotype. CONCLUSION: All genotypes found in this study are potentially pathogenic. The T4 genotype is the main genotype of Acanthamoeba responsible for amoebic keratitis. Resource water is a potential risk factor for the distribution of free-living amoeba. Therefore, more attention of health authorities to determine, training and prevention from infection are recommended.

Next-Generation Sequencing Assessment of Eukaryotic Diversity in Oil Sands Tailings Ponds Sediments and Surface Water.

Tailings ponds in the Athabasca oil sands (Canada) contain fluid wastes, generated by the extraction of bitumen from oil sands ores. Although the autochthonous prokaryotic communities have been relatively well characterized, almost nothing is known about microbial eukaryotes living in the anoxic soft sediments of tailings ponds or in the thin oxic layer of water that covers them. We carried out the first next-generation sequencing study of microbial eukaryotic diversity in oil sands tailings ponds. In metagenomes prepared from tailings sediment and surface water, we detected very low numbers of sequences encoding eukaryotic small subunit ribosomal RNA representing seven major taxonomic groups of protists. We also produced and analysed three amplicon-based 18S rRNA libraries prepared from sediment samples. These revealed a more diverse set of taxa, 169 different OTUs encompassing up to eleven higher order groups of eukaryotes, according to detailed classification using homology searching and phylogenetic methods. The 10 most abundant OTUs accounted for > 90% of the total of reads, vs. large numbers of rare OTUs (< 1% abundance). Despite the anoxic and hydrocarbon-enriched nature of the environment, the tailings ponds harbour complex communities of microbial eukaryotes indicating that these organisms should be taken into account when studying the microbiology of the oil sands.

Effect of pond water depth on snail populations and fish-borne zoonotic trematode transmission in juvenile giant gourami (Osphronemus goramy) aquaculture nurseries.

Infection with fish-borne zoonotic trematodes (FZT) is an important public health problem in many parts of Southeast Asia. People become infected with FZT when eating raw or undercooked fish that contain the infective stage (metacercariae) of FZT. The parasites require specific freshwater snails as first intermediate host and a variety of fish species, both wild caught and cultured, as second intermediate host. Aquaculture production has grown almost exponentially in SE Asia and in order to produce fish free from FZT metacercariae, it is important to mitigate factors promoting transmission to fish. Here we report results from a cross-sectional study to look at the association between pond depth and infection with FZT in giant gourami nursery ponds. Density of intermediate host snails was positively associated with pond depth (count ratio associated with a 1m increase in pond depth was 10.4 (95% C.L.: 1.61-67.1, p<0.5)) and this may partly explain the higher prevalence and intensity of FZT infection in juvenile fish. High fry stocking density (>200 fry m(-3)) was associated with lower host snail density (count ratio=0.15) than low stocking density (<100 fry m(3)). Ponds stocked with 100-200 fry m(-3) had snail counts 0.76 (95% C.L.: 0.33-1.75, p n.s.) of those in ponds stocked with fry density of <100 fry m(-3). Since density of intermediate snail hosts was associated with FZT transmission to fish, effort should be taken to reduce snail density prior to stocking the fry, but focus should also be on habitats surrounding ponds as transmission may occur through cercariae produced outside ponds and carried into ponds with water pumped into ponds.

Caracterización de la transmisión de la malaria por Plasmodium vivax en la región fronteriza de Panamá con Costa Rica en el municipio de Barú, Panamá / Characterization of Plasmodium vivax malaria transmission at the border of Panamá and Costa Rica

Introducción. Pocos estudios describen los factores asociados con la dinámica de transmisión de la malaria, o paludismo, por Plasmodium vivax en las regiones endémicas de Panamá. Objetivo. Caracterizar la dinámica de transmisión de la malaria producida por P. vivax en la región fronteriza de Panamá con Costa Rica. Materiales y métodos. Se llevó a cabo un estudio observacional, descriptivo y transversal. Se evaluaron la incidencia parasitaria anual, el índice de láminas positivas y el índice anual de exámenes de sangre. Se identificaron los anofelinos vectores, y se caracterizaron sus criaderos preferenciales, densidad larvaria e índice de picada/hombre/noche. Se hizo búsqueda pasiva y activa de casos sospechosos mediante examen de gota gruesa. Resultados. De 10.401 muestras de gota gruesa, 83 resultaron positivas para P. vivax. El 84 % de los casos provenía de zonas rurales, el 79 % constituía una población económicamente activa, la mediana de edad fue de 36 años y, la media, de 30 años. El 58,5 % de los casos fueron de sexo masculino. La incidencia parasitaria anual fue de 4,1 por 1.000 habitantes; el índice de láminas positivas fue de 0,8 % y el índice anual de exámenes de sangre fue de 51,9 %. El 65,0 % de los casos diagnosticados registró entre 100 y 2.000 parásitos/μl de sangre. Se identificaron los mosquitos vectores Anopheles albimanus y An. punctimacula. Conclusión. Es necesario el seguimiento de estudios entomológicos, el fortalecimiento de la vigilancia epidemiológica, la consideración de los factores de riesgo y la realización de un trabajo en coordinación con las autoridades de salud de Costa Rica, para controlar la malaria en esta región.

Introduction. Few studies have described the factors associated with Plasmodium vivax transmission dynamics in endemic regions from Panamá. Objective. Malaria transmission dynamics produced by P. vivax were characterized at the border between Panamá and Costa Rica. Materials and methods. In the municipality of Barú, an observational, descriptive and cross-sectional study was undertaken to measure the annual parasite index (API), slide positivity index (SPR), and the annual blood examination rate (ABER). The most frequent symptoms and signs in malaria patients were recorded. The anopheline species were identified in the area and the preferred larval habitats, the density of larval populations in the larval habitats and the bites/human/night were characterized. Results. Of a total of 10,401 thick smear blood samples, 83 were positive for P. vivax. Of these, 84% came from rural areas and 79% were from economically active individuals. The median and average ages were 36 and 30 years, respectively, and 58.5% of the malaria cases were male. API was 4.1/1,000 inhabitants; SPR was 0.8% and ABER was 51.9%. Of the diagnosed cases, 54% showed blood parasitemias ranging between 100-2,000 parasites/μl. The majority of the cases were observed in May and June. Two mosquito vector species were identified-- Anopheles albimanus and An. punctimacula. Conclusion. These observations indicate the advisibility of continued entomological studies, strengthening of epidemiological surveillance, consideration of additional risk factors and evaluation of work performance in the border region. This will require coordination with health authorities of both countries to control malaria in this region.