CHARACTERIZATION OF EIMERIA LANCASTERENSIS AND EIMERIA ONTARIOENSIS (APICOMPLEXA: EIMERIIDAE) FOUND IN EASTERN GRAY SQUIRRELS, SCIURUS CAROLINENSIS (RODENTIA: SCIURIDAE), FROM ARKANSAS AND OKLAHOMA.

We report the morphological characteristics of oocysts of Eimeria lancasterensisJoseph, 1969, collected from 6 of 6 (100%) eastern gray squirrels, Sciurus carolinensis, collected in Arkansas (n = 3) and Oklahoma (n = 3), and Eimeria ontarioensisLee and Dorney, 1971, recovered from an individual of S. carolinensis from Arkansas. Oocysts of E. lancasterensis were ovoidal to ellipsoidal, measuring (L × W) 24.0 × 14.6 (18-29 × 12-16) µm; shape index (L/W) was 1.6 (1.3-1.8). A micropyle and an oocyst residuum were absent, but up to 2 polar granules were present. Oocysts of E. ontarioensis were piriform and measured 40.6 × 26.0 (37-44 × 23-28); L/W was 1.6 (1.5-1.7). These oocysts possessed a distinct micropyle and rarely a polar granule but lacked an oocyst residuum. The DNA was isolated from both eimerians, and the 18S rDNA genetic markers were PCR-amplified, cloned, sequenced, and analyzed. To our knowledge, this study represents the first time 18S DNA sequence data have been generated from E. lancasterensis and E. ontarioensis found in North American sciurid hosts, as well as new geographic distribution records for these coccidians. In addition, we also include a tabular summary of these 2 species of Eimeria from Sciurus spp. worldwide, with information on their hosts, distribution, and taxonomically important morphological characteristics, including key measurements of oocysts and sporocysts.

Coccidian Parasites of Flying Squirrels, Glaucomys spp. (Rodentia: Sciuridae), from Alaska and Arkansas, with a Description of a New Species of Eimeria (Apicomplexa: Eimeriidae).

New World flying squirrels, Glaucomys spp., are nocturnal arboreal sciurid rodents that have been previously surveyed for coccidial parasites. To date, 4 species of Eimeria have been reported from 2 species of Glaucomys. Here we report 2 species of eimerians from southern flying squirrels (Glaucomys volans) and the endemic Prince of Wales flying squirrel (Glaucomys sabrinus griseifrons). Oocysts of Eimeria dorneyi Levine and Ivens were found to be passing in the feces of 4 G. s. griseifrons from Alaska and a new species of Eimeria was present in feces from 6 G. volans from Arkansas. Oocysts of Eimeria hnidai n. sp. are ellipsoidal with a bilayered wall, measure 23.7 × 13.7 µm, and have a length/width (L/W) ratio of 1.7; a micropyle and oocyst residuum are absent but polar granule(s) are present. Sporocysts are ellipsoidal-elongate and measure 11.8 × 4.9 µm, L/W 2.2; Stieda body is present but sub-Stieda and para-Stieda bodies are absent. The sporocyst residuum is composed of small indistinct granules along the edge or in the center of the sporocyst. This is the first coccidian reported from G. volans from Arkansas as well as the initial coccidian (E. dorneyi) reported from G. s. griseifrons from Alaska. We also provide a summation of the coccidia known from North American flying squirrels.

SARS-CoV-2 and cardiovascular complications: From molecular mechanisms to pharmaceutical management.

The coronavirus disease 2019 (COVID-19), elicited by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, is a pandemic public health emergency of global concern. Other than the profound severe pulmonary damage, SARS-CoV-2 infection also leads to a series of cardiovascular abnormalities, including myocardial injury, myocarditis and pericarditis, arrhythmia and cardiac arrest, cardiomyopathy, heart failure, cardiogenic shock, and coagulation abnormalities. Meanwhile, COVID-19 patients with preexisting cardiovascular diseases are often at a much higher risk of increased morbidity and mortality. Up-to-date, a number of mechanisms have been postulated for COVID-19-associated cardiovascular damage including SARS-CoV-2 receptor angiotensin-converting enzyme 2 (ACE2) activation, cytokine storm, hypoxemia, stress and cardiotoxicity of antiviral drugs. In this context, special attention should be given towards COVID-19 patients with concurrent cardiovascular diseases, and special cardiovascular attention is warranted for treatment of COVID-19.

A new species of Eimeria Schneider, 1885 (Apicomplexa: Eimeriidae) from the eastern gray squirrel, Sciurus carolinensis (Rodentia: Sciuridae: Sciurinae: Sciurini) from Oklahoma, USA.

A new species of Eimeria Schneider, 1885 is described from an eastern gray squirrel (Sciurus carolinensis) from McCurtain County, Oklahoma, USA. Oöcysts of Eimeria lukfataensis n. sp. are ellipsoidal with a rough pitted bi-layered wall, measure 23.8 × 14.9 µm, and have a length/width (L/W) ratio of 1.6; a micropyle is absent but an oöcyst residuum and polar granule(s) are present. Sporocysts are ellipsoidal and measure 12.5 × 6.1 µm, L/W 2.0; Stieda and sub-Stieda bodies are present, but para-Stieda body is absent. The sporocyst residuum is composed of small indistinct granules along the edge or in the center of the sporocyst. This is the first species of coccidian reported from S. carolinensis from Oklahoma and only the fourth species from the sciurid tribe Sciurini with oöcysts possessing an oöcyst residuum.

Three new coccidians (Cyclospora, Eimeria) from eastern moles, Scalopus aquaticus (Linnaeus) (Mammalia: Soricomorpha: Talpidae) from Arkansas, USA.

Three new species of coccidians (Apicomplexa: Eimeriidae) are described from eastern moles, Scalopus aquaticus (Linnaeus) from Arkansas. Oöcysts of Cyclospora duszynskii n. sp. are subspheroidal with a smooth bi-layered wall, measure 11.4 × 10.0 µm, and have a length/width (L/W) ratio of 1.1; both micropyle and oöcyst residuum are absent, but a single polar granule is present. Sporocysts are ellipsoidal and measure 7.2 × 5.4 µm, L/W 1.3; an indistinct Stieda body is present, but the sub-Stieda and para-Stieda bodies are absent and the sporocyst residuum is composed of medium to large granules of different sizes along the edge of the sporocyst. Oöcysts of Cyclospora yatesi n. sp. are subspheroidal to ovoidal with an ornate outer wall, measure 17.0 × 15.2 µm, L/W 1.1; both micropyle and oöcyst residuum are absent, but a single polar granule is present. Sporocysts are ellipsoidal and measure 9.7 × 7.3 µm, L/W 1.3; an indistinct Stieda body is present, but sub-Stieda and para-Stieda bodies are absent and the sporocyst residuum is composed of medium to large granules of different sizes along the edge of the sporocyst. Oöcysts of Eimeria paulettefordae n. sp. are ovoidal to ellipsoidal with an ornate outer wall, measure 30.0 × 25.4 µm, L/W 1.2; both micropyle and oöcyst residuum are absent, but a single polar granule is present. Sporocysts are ellipsoidal and measure 12.6 × 9.2 µm, L/W 1.4; a button-like Stieda body is present, but sub-Stieda and para-Stieda bodies are absent and the sporocyst residuum is composed of medium to large granules of different sizes along the edge of the sporocyst. These are the first coccidians described from Arkansas populations of S. aquaticus. In addition, a summary is provided on the cyclosporans and eimerians from North American talpids.

A new eimerian (Apicomplexa: Eimeriidae), from ornate box turtle, Terrapene ornata (Agassiz) (Testudines: Emydidae) from northwest Arkansas, USA.

A new species of Eimeria Schneider, 1875 (Apicomplexa: Eimeriidae) collected from an ornate box turtle, Terrapene ornata (Agassiz) from Arkansas, USA, is described. Oöcysts of Eimeria doddi n. sp. are ovoidal to ellipsoidal with a smooth, light to darker brown, bi-layered wall, measure 21.1 × 14.0 µm, and have a length/width (L/W) ratio of 1.5; both micropyle and oöcyst residuum are absent, but a polar granule is present. Sporocysts are ellipsoidal, 9.9 × 6.1 µm, L/W 1.6; the Stieda body is present, but the sub-Stieda and para-Stieda bodies are absent and the sporocyst residuum is composed of small granules in a cluster. Sporozoites have a spheroidal anterior refractile body, a subspheroidal posterior refractile body, and one centrally-located nucleus. This is the third description of an eimerian from the turtle genus Terrapene Merrem and the second from T. ornata. In addition, we report Eimeria ornata McAllister & Upton, 1989 from T. ornata from Texas.

Comparison of the ITS1 and ITS2 rDNA in Eimeria callospermophili (Apicomplexa:Eimeriidae) from sciurid rodents.

The taxonomy of the coccidia has historically been morphologically based. The purpose of this study was to establish if conspecificity of isolates of Eimeria callospermophili from 4 ground-dwelling squirrel hosts (Rodentia: Sciuridae) is supported by comparison of rDNA sequence data and to examine how this species relates to eimerian species from other sciurid hosts. Eimeria callospermophili was isolated from 4 wild-caught hosts, i.e., Urocitellus elegans, Cynomys leucurus, Marmota flaviventris , and Cynomys ludovicianus . The ITS1 and ITS2 genomic rDNA sequences were PCR generated, sequenced, and analyzed. The highest intraspecific pairwise distance values of 6.0% in ITS1 and 7.1% in ITS2 were observed in C. leucurus. Interspecific pairwise distance values > 5% do not support E. callospermophili conspecificity. Generated E. callospermophili sequences were compared to Eimeria lancasterensis from Sciurus niger and Sciurus niger cinereus and to Eimeria ontarioensis from S. niger. A single, well-supported clade was formed by E. callospermophili amplicons in neighbor joining and maximum parsimony analyses. However, within the clade, there was little evidence of host or geographic structuring of the species.

Species of Eimeria (Apicomplexa: Eimeriidae) from tree squirrels (Sciurus niger) (Rodentia: Sciuridae) and analysis of the ITS1, ITS2, and 5.8S rDNA.

During the winter of 2004, 48 fecal samples were collected from live-trapped fox squirrels (Sciurus niger) from central Wyoming (Natrona County) and examined for species of Eimeria. Two species, Eimeria lancasterensis (prevalence, 65%) and Eimeria ontarioensis (prevalence, 27%), were identified. Genomic DNA sequences ITS1 and ITS2 were amplified, cloned, and sequenced. Additional sequences from E. lancasterensis isolated from a Delmarva fox squirrel (Sciurus niger cinereus) collected on Chincoteague Island, Virginia, were also identified. Comparison of pairwise distances suggests that E. lancasterensis from Wyoming and Virginia are conspecific. Maximum Parsimony tree construction identified 2 lineages, one E. ontarioensis and one E. lancasterensis; and both lineages had a strong bootstrap support (100%). The Maximum Parsimony analysis was unable to resolve the Wyoming and Virginia strains.

Analysis of the conserved N-terminal domains in major ampullate spider silk proteins.

Major ampullate silk, also known as dragline silk, is one of the strongest biomaterials known. This silk is composed of two proteins, major ampullate spidroin 1 (MaSp1) and major ampullate spidroin 2 (MaSp2). Only partial cDNA sequences have been obtained for these proteins, and these sequences are toward the C-terminus. Thus, the N-terminal domains have never been characterized for either protein. Here we report the sequence of the N-terminal region of major ampullate silk proteins from three spider species: Argiope trifasciata, Latrodectus geometricus, and Nephila inaurata madagascariensis. The amino acid sequences are inferred from genomic DNA clones. Northern blotting experiments suggest that the predicted 5' end of the transcripts are present in fibroin mRNA. The presence of more than one Met codon in the N-terminal region indicates the possibility of translation of both a long and a short isoform. The size of the short isoform is consistent with the published, cDNA based, N-terminal sequence found in flagelliform silk. Analyses comparing the level of identity of all known spider silk N-termini show that the N-terminus is the most conserved part of silk proteins. Two DNA sequence motifs identified upstream of the putative transcription start site are potential silk fibroin promoter elements.

Brown widow (Latrodectus geometricus) major ampullate silk protein and its material properties.

Major ampullate (dragline) silk is the main web component as well as the silk that spiders use for a lifeline when they fall. This silk has a breaking stress of 4.6 GPa, which is similar to that of Kevlar. The majority of the previous mechanical testing studies involved the major ampullate silk from orb-weaving spiders. To date, there have been no reports on dragline silk mechanical properties from a cob-weaver, brown widow Latrodectus geometricus. L. geometricus dragline was found to be composed of MaSp1, MaSp2, and MaSp-like proteins all of which have highly conserved amino acid motifs, especially the GGX, GA and poly A for MaSp1 and GPGGX and poly A for MaSp2. These sequences are the same as those found in the silks of orb-weaving spiders. To determine if protein sequences influence the material properties of the silk, mechanical testing was performed on single strands of silk fibers from adult female L. geometricus spiders. The 3 cm long silk fibers were tested for breaking stress and strain with a MTS Synergie 100 mechanical testing system using a 50 g load cell with the cross-head speed set at 10 mm/min. The breaking stress and strain were measured for 20 replicate samples and averaged. The values of 0.83 +/- 0.19 GPa for stress and 0.14 +/- 0.06 for strain shows that brown widow dragline is weaker than the orb-weaving spiders.