scholarly journals Stenamoeba dejonckheerei sp. nov., a Free-Living Amoeba Isolated from a Thermal Spring

Pathogens ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 586
Author(s):  
Manuel Alejandro Borquez-Román ◽  
Luis Fernando Lares-Jiménez ◽  
Libia Zulema Rodriguez-Anaya ◽  
Jose Reyes Gonzalez-Galaviz ◽  
Paul A. Fuerst ◽  
...  

Two amoeboid organisms were obtained from water samples taken from a thermal spring, "Agua Caliente", in Northwestern Mexico. The isolates were obtained when samples were cultivated at 37 °C on non-nutrient agar coated with Escherichia coli. The initial identification of the isolates was performed morphologically using light microscopy. The samples were found to have trophozoite morphology consistent with members of the genus Stenamoeba, a genus derived in 2007 from within the abolished polyphyletic genus Platyamoeba. Further analysis was performed by sequencing PCR products obtained using universal eukaryotic primers for the small subunit ribosomal ribonucleic acid (SSU rRNA) gene. Sequencing primers were designed to allow the comparison of the 18S rRNA gene sequences of the new isolates with previous sequences reported for Stenamoeba. Phylogenetic relationships among sequences from Stenamoeba were determined using Maximum Likelihood analysis. The results showed the two "Agua Caliente" sequences to be closely related, while clearly separating them from those of other Stenamoeba taxa. The degrees of sequence differentiation from other taxa were considered sufficient to allow us to propose that the Mexican isolates represent a new species.

2016 ◽  
Vol 4 (1) ◽  
pp. 25 ◽  
Author(s):  
Gomathi Jeyam Mookkaiah ◽  
Ramanibai Ravichandran

<p>In the present investigation to isolate freshwater calanoid copepods (<em>Diaptomus sicilis</em>) was characterized and identify the organisms by 18S rRNA sequencing. Plankton samples containing <em>D. sicilis</em> were collected during January 2014 (Post-monsoon) from Madippakkam Lake (12°57'41"N80°11'27"E) Chennai, Tamil Nadu. Immediately after sampling, specimens for genetic analyses were fixed in 95% ethyl alcohol. The total DNA was extracted from the individual copepod <em>D. sicilis</em> using Qiagen Blood tissue kit. The nuclear small subunit 18S rRNA gene was amplified using the Universal primer LCO —1490 (5’-GGTCAACAAATCATAAAGATATTGG-3’) and HCO-2198 (5’-TAAACTTCAGGGTGACCAAAAAATCA-3’). PCR products were loaded onto a 1% TAE agarose gel. Sequences were carried out an automated sequencer. The nucleotide sequence of 1282 base pair region of 18S rRNA was determined for D. sicilis. The similarity of sequences of <em>D. sicilis</em> was retrieved by BLASTn pro­gram and maximum identity and E-value was 76% and 0.00, respectively. The PCR products of <em>D. sicilis</em> individuals showed 80% similarity with the partial nuclear small subunit 18S rRNA gene region of other calanoid copepods. Based on molecular data the freshwater Calanoid copepods showed different algorithms and similar types of topologies useful for designing molecular analyses using phylogeny tree construction.Present molecular stud­ies on the relationship of D. sicilis with other freshwater calanoid copepods indicate that this species is close to <em>D. castor</em> followed by <em>D. keniraensis</em><em>.</em></p>


2015 ◽  
Vol 65 (Pt_8) ◽  
pp. 2549-2561 ◽  
Author(s):  
Xiaozhong Hu ◽  
Yangbo Fan ◽  
Alan Warren

The benthic urostylid ciliate Apoholosticha sinica Fan et al., 2014 was isolated from a salt marsh at Blakeney, UK, and reinvestigated using light microscopy and small-subunit rRNA gene sequencing. Morphologically, it corresponds well with the original description. Several stages of divisional morphogenesis and physiological reorganization were also observed from which the following could be deduced: (i) the oral apparatus is completely newly built in the proter; (ii) frontal-ventral-transverse cirral anlage II does not produce a buccal cirrus; (iii) each of the posteriormost three or four anlagen contributes one transverse cirrus at its posterior end; (iv) a row of frontoterminal cirri originates from the rearmost frontal-ventral-transverse cirral anlage; (v) the last midventral row is formed from the penultimate frontal-ventral-transverse cirral anlage. Based on new data, two diagnostic features were added to the genus definition: (i) the midventral complex is composed of midventral pairs and midventral row and (ii) pretransverse ventral cirri are absent. Based on a combination of morphological and morphogenetic data, the genus Apoholosticha is assigned to the recently erected subfamily Nothoholostichinae Paiva et al., 2014, which is consistent with sequence comparison and phylogenetic analyses based on SSU rRNA gene data. It is also concluded that this benthic species, previously reported only from China, is not an endemic form.


Nematology ◽  
2018 ◽  
Vol 20 (7) ◽  
pp. 653-669 ◽  
Author(s):  
Oleg Gorgadze ◽  
Elena Fanelli ◽  
Manana Lortkhipanidze ◽  
Alberto Troccoli ◽  
Medea Burjanadze ◽  
...  

Summary A new species of entomopathogenic nematode, Steinernema borjomiense n. sp., was isolated from the body of the host insect, Oryctes nasicornis (Coleoptera: Scarabaeidae), in Georgia, in the territory of Borjomi-Kharagauli. Morphological characters indicate that the new species is closely related to species of the feltiae-group. The infective juveniles are characterised by the following morphological characters: body length of 879 (777-989) μm, distance between the head and excretory pore = 72 (62-80) μm, pharynx length = 132 (122-142) μm, tail length = 70 (60-80) μm, ratio a = 26.3 (23.0-29.3), H% = 45 (40-51), D% = 54 (47-59), E% = 102 (95-115), and lateral fields consisting of seven ridges (eight incisures) at mid-body. Steinernema borjomiense n. sp. was molecularly characterised by sequencing three ribosomal regions (the ITS, the D2-D3 expansion domains and the 18S rRNA gene) and the mitochondrial COI gene. Phylogenetic analyses revealed that S. borjomiense n. sp. differs from all other known species of Steinernema and is a member of the monticolum-group.


2018 ◽  
Author(s):  
Julie Lattaud ◽  
Frédérique Kirkels ◽  
Francien Peterse ◽  
Chantal V. Freymond ◽  
Timothy I. Eglinton ◽  
...  

Abstract. Long chain diols (LCDs) occur widespread in marine environments and also in lakes and rivers. Transport of LCDs from rivers may impact the distribution of LCDs in coastal environments, however relatively little is known about the distribution and biological sources of LCDs in river systems. In this study, we investigated the distribution of LCDs in suspended particulate matter (SPM) of three river systems (Godavari, Danube, and Rhine) in relation with season, precipitation, temperature, and source catchments. The dominant long-chain diol is the C32 1,15-diol followed by the C30 1,15-diol in all studied river systems. In regions influenced by marine waters, such as delta systems, the fractional abundance of the C30 1,15-diol is substantially higher than in the river itself, suggesting different LCD producers in marine and freshwater environments. A change in the LCD distribution along the downstream transects of the rivers studied was not observed. However, an effect of river flow is observed, i.e. the concentration of the C32 1,15-diol is higher in stagnant waters, such as reservoirs and during seasons with river low stands. A seasonal change in the LCD distribution was observed in the Rhine, likely due to a change in the producers. Eukaryotic diversity analysis by 18S rRNA gene sequencing of SPM from the Rhine showed extremely low abundances of sequences (i.e.


2021 ◽  
Author(s):  
Erin M Stayton ◽  
Megan Lineberry ◽  
Jennifer Thomas ◽  
Tina Bass ◽  
Kelly Allen ◽  
...  

Abstract Background: Babesia species are intraerythrocytic Apicomplexan parasites that infect a wide range of vertebrate hosts. These pathogens are typically transmitted either by tick vectors or by direct blood-to-blood contact, and may cause life-threatening clinical disease such as thrombocytopenia, hemolytic anemia, and acute renal failure in canine hosts. While Babesia vogeli and Babesia gibsoni infections have both been reported in Oklahoma, reports of B. conradae infections have been limited to California. Methods: Whole blood samples were collected in EDTA tubes from all dogs in four separate kennels in Oklahoma. DNA was extracted from each blood sample and a nested PCR was performed using general Apicomplexan primers for the partial 18S rRNA gene. PCR products were electrophoresed in agarose matrix and appropriately sized amplicons were sequenced. Sequences were compared to reference 18S rRNA sequences available in GenBank, and samples with >98% homology to B. conradae (GenBank MK256976) were considered positive. B. conradae positive dogs were then treated with atovaquone (13.5 mg/kg TID) and azithromycin (10 mg/kg SID) for 10 days and retested at 30 and 60 days post treatment by PCR. Results: Fifteen of 40 dogs tested positive for B. conradae with 98–100% sequence homology to B. conradae from California. All positive cases were coyote-hunting Greyhounds. Treatment of clinically ill dogs with atovaquone and azithromycin resulted in complete clinical recovery in clinically ill dogs and all treated dogs had negative follow-up PCR at 30 and 60 days post treatment. Conclusions: Collectively, this study (i) documents the occurrence of B. conradae in Oklahoma, (ii) highlights this pathogen as a differential to be considered when clinical signs are present, and (iii) supports the use of atovaquone and azithromycin as effective treatment in these cases.


2020 ◽  
Vol 119 (12) ◽  
pp. 4291-4295
Author(s):  
Katharina Lichtmannsperger ◽  
Josef Harl ◽  
Katharina Freudenthaler ◽  
Barbara Hinney ◽  
Thomas Wittek ◽  
...  

AbstractFecal samples of 177 calves of up to 180 days of age with diarrhea from 70 farms in Austria were examined to obtain information on the occurrence of Cryptosporidium species. Initially, all samples were examined by phase-contrast microscopy. Cryptosporidium-positive samples (55.4%; n = 98) were screened by gp60 PCR, resulting in 68.4% (n = 67) C. parvum–positive samples. The remaining 31 gp60-PCR-negative and the phase-contrast microscopy negative samples (n = 79) were screened by PCR targeting a 700 bp fragment of the 18S rRNA gene. Sequencing of the PCR products revealed the presence of C. parvum (n = 69), C. ryanae (n = 11), and C. bovis (n = 7). The latter two species have never been described in Austria. C. parvum–positive samples were genotyped at the gp60 gene locus, featuring four subtypes (IIaA15G2R1, IIaA21G2R1, IIaA19G2R1, IIaA14G1R1). The most frequently detected subtype IIaA15G2R1 (n = 52) was present in calves from 30 different farms. IIaA14G1R1 (n = 5) occurred on a single farm, subtype IIaA21G2R1 (n = 4) on two farms, and subtype IIaA19G2R1 (n = 4) on three farms. The results confirm the widespread occurrence of zoonotic C. parvum in diarrheic calves.


2020 ◽  
Vol 32 (4) ◽  
pp. 2561-2573
Author(s):  
Wenlei Wang ◽  
Lei Wu ◽  
Kai Xu ◽  
Yan Xu ◽  
Dehua Ji ◽  
...  

Abstract Microorganisms play important roles in the growth and development of macroalgae. Still, the biodiversity of the epiphytic microbial community associated with the economically important red alga Pyropia haitanensis during the cultivation period remains uncharacterized, especially the effects of P. haitanensis cultivation on the microbial community of surrounding seawater. Here, we isolated epiphytic microbes from P. haitanensis during the thallus stage during oceanic cultivation and the conchocelis stage during industrial cultivation. The dynamic diversity patterns, as determined by 16S and 18S rRNA gene sequencing of the bacterial and fungal communities, respectively, associated with P. haitanensis and seawater in the presence and absence of algal cultivation were investigated. A notable distinction was observed between the microbial communities of seawater with and without P. haitanensis cultivation. Additionally, the alpha-diversity of seawater with P. haitanensis cultivation was significantly greater than without P. haitanensis cultivation. Cyanobacteria were the dominant species in the latter, while Rhodobacteraceae was enriched in the former. Furthermore, there were significant differences in the microbial community of P. haitanensis at the thallus and conchocelis stages. Seawater properties had significant direct effects on the microbial diversity of P. haitanensis and cultivation seawater, but not on non-cultivation seawater. The enriched microbial presence might promote thallus morphogenesis and be beneficial for the growth and development of both the thallus and conchocelis stages. These findings expand our knowledge of the bacteria and fungi that are beneficial for Pyropia nursery seeding and cultivation, as well as the effects of P. haitanensis cultivation on the seawater microbial community.


2018 ◽  
Vol 15 (13) ◽  
pp. 4147-4161 ◽  
Author(s):  
Julie Lattaud ◽  
Frédérique Kirkels ◽  
Francien Peterse ◽  
Chantal V. Freymond ◽  
Timothy I. Eglinton ◽  
...  

Abstract. Long-chain diols (LCDs) occur widespread in marine environments and also in lakes and rivers. Transport of LCDs from rivers may impact the distribution of LCDs in coastal environments, however relatively little is known about the distribution and biological sources of LCDs in river systems. In this study, we investigated the distribution of LCDs in suspended particulate matter (SPM) of three river systems (Godavari, Danube, and Rhine) in relation with precipitation, temperature, and source catchments. The dominant long-chain diol is the C32 1,15-diol followed by the C30 1,15-diol in all studied river systems. In regions influenced by marine waters, such as delta systems, the fractional abundance of the C30 1,15-diol is substantially higher than in the river itself, suggesting different LCD producers in marine and freshwater environments. A change in the LCD distribution along the downstream transects of the rivers studied was not observed. However, an effect of river flow is observed; i.e., the concentration of the C32 1,15-diol is higher in stagnant waters such as reservoirs and during seasons with river low stands. A seasonal change in the LCD distribution was observed in the Rhine, likely due to a change in the producers. Eukaryotic diversity analysis by 18S rRNA gene sequencing of SPM from the Rhine showed extremely low abundances of sequences (i.e., < 0.32 % of total reads) related to known algal LCD producers. Furthermore, incubation of the river water with 13C-labeled bicarbonate did not result in 13C incorporation into LCDs. This indicates that the LCDs present are mainly of fossil origin in the fast-flowing part of the Rhine. Overall, our results suggest that the LCD producers in rivers predominantly reside in lakes or side ponds that are part of the river system.


Fine Focus ◽  
2018 ◽  
Vol 4 (1) ◽  
pp. 83-100 ◽  
Author(s):  
Kathleen A. Page ◽  
Meghan K. Flannery

We identified chytrid fungi that were attached to pine pollen on the surface of Crater Lake. Fungi were identified by large subunit (LSU) rRNA gene sequencing of lake pollen extracts and by isolation of a chytrid fungus that was present on the pollen. LSU rRNA PCR products were cloned, sequenced and identified. The majority of eukaryotic LSU rRNA sequences associated with pollen were found to be members of the chytrid order Rhizophyidiales. A fungal isolate was characterized culturally, morphologically, and by DNA sequencing and was identified as a member of the genus Paranamyces, in the order Rhizophydiales. In addition, protist LSU rRNA sequences from the phylum Ciliophora were found. The concentrations of dissolved organic matter, nitrogen, and phosphate in surface water that had visible pollen rafts increased according to the concentration of pollen in the water. Each of these nutrients was detected at several fold higher levels in water with pollen rafts as compared to surface water lacking pollen rafts. These results provide evidence for the role of chytrid fungi in nutrient release from pollen deposited on Crater Lake.


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