New Technique for Identification of Ichthyoplankton and Its Application in Biomonitoring Studies, Management and Conservation of Neotropical Fish.

Despite significant advancements in ichthyoplankton collection and data processing, challenges persist in the taxonomic identification of these organisms, particularly their eggs. To overcome these challenges, a novel technique has been developed to facilitate the identification of live eggs collected directly in wild. This user-friendly technique includes the collection, processing of the material, and field incubation. Sampling must be conducted using a pelagic net towed at low speed, preferably during early evening. The material processing involves pre-sorting and sorting to remove eggs and larvae. The separated eggs, kept in an aerated bowl, can be identified based on their morphological and meristic characteristics. Unidentified eggs can be placed in plastic bags with oxygen and incubated directly in the aquatic environment for 48-72 h. After this incubation period, the hatched larvae at the yolk-sac or preflexion stage, are identified to the lowest possible taxonomic level. Depending on the study's purpose, hatched larvae and field-collected larvae can be transported to research centers for further development, released back into the natural environment, or fixed to complete the collection. The application of this technique supports management and monitoring programs by identifying spawning areas through egg identification, forming broodstock, and replenishing threatened species, thereby enhancing scientific collections of ichthyoplankton. Additionally, it reduces mortality in ichthyoplankton techniques, including endangered species. Therefore, we believe that this novel taxonomic technique for identifying live ichthyoplankton represents a paradigm shift in the monitoring, management, and conservation of fish, as well as in ecological stewardship and advances in this area of research.

Ileal inflammation is reduced due to treatment with a metalloprotease from BmooMP-α-I snake venom in an experimental model of Toxoplasma gondii infection.

The selection process for advanced therapies in patients with inflammatory bowel diseases (IBDs) must prioritize safety, especially when considering new biologic agents or oral molecule modulators. In C57BL/6 mice, oral infection with Toxoplasma gondii induces intestinal inflammation through excessive tumor necrosis factor (TNF) production, making TNF neutralization a potential therapeutic intervention. Considering this, the present study aimed to evaluate the therapeutic effects of BmooMP-α-I, a snake venom metalloprotease isolated from Bothrops moojeni, which could promote TNF hydrolysis, in treating T. gondii-induced ileitis. The results showed that C57BL/6 mice orally infected with 50 cysts of T. gondii from the Me49 strain and treated with BmooMP-α-I exhibited prolonged survival and improved morbidity scores. Additionally, the treatment ameliorated both the macroscopic and microscopic aspects of the intestine, reduced macrophage influx, and decreased the production of inflammatory mediators by mesenteric lymph node cells. These findings provide compelling experimental evidence supporting the ability of BmooMP-α-I to alleviate ileal inflammation. Considering that the currently available therapeutic protocols are not completely effective and often result in side effects, the exploration of alternative strategies involving novel therapeutic agents, as demonstrated in this study, has the potential to significantly enhance the quality of life for patients suffering from inflammatory bowel diseases.

Morphologic and Genetic Analysis of Synhimantus (Synhimantus) laticeps from a Long-Eared Owl (Asio otus).

The long-eared owl (Asio otus) is a medium-sized owl species that is well-distributed in almost all of the territories in Portugal. Nematodes were found in the oral cavity of a long-eared owl (A. otus) admitted to CRASSA (Wildlife Rehabilitation Centre of Santo André). During a physical exam and stabilization of the bird, five nematodes were collected. The worms were examined and measured under light microscopy, and photos were taken. After a morphological analysis was conducted, all the nematodes (five females) were identified as Synhimantus (Synhimantus) laticeps. Two specimens were subjected to molecular analysis, which confirmed the result. This study provides a combined morphological and genetic approach to S. laticeps. To the authors' best knowledge, this is the first report including genetic sequencing of S. laticeps in a long-eared owl (A. otus) from Portugal.

Overview of SARS-COV-2 infection at the Butantan Penitentiary Progression Center.

OBJECTIVE: To estimate the prevalence of exposure to the SARS-CoV-2 virus among individuals living in restricted freedom. METHODS: A seroprevalence survey was carried out with the population of the female penitentiary of the Centro de Progressão Penitenciária (CPP) in Butantan (municipality of São Paulo), between June 24 and August 20, 2020. During this period, according to the Secretariat of Penitentiary Administration (SAP), the positivity of rapid tests among inmates ranged from 65% to 78%. The evaluation method used in the study was the "One Step COVID-19" rapid test (chromatography), from the company Wondfo, also using the RT-PCR method in symptomatic participants to confirm the viral condition. The study population consisted of 879 female inmates and 170 employees of the institution. RESULTS: The prevalence of total antibodies (IgG/IgM) against the SARS-CoV-2 virus in the total population of 1049 study participants was 6.1%; among the population of 879 inmates,a prevalence of 5.8% was observed, and among the institution's employees, 7.5%. CONCLUSIONS: The prevalence of covid-19 at the Butantan CPP was low, which is due to the implementation of simple prevention measures at the institution, such as the use of masks (with appropriate changes), emphasis on hygiene, hand washing and social distancing, in addition to other strategies, such as suspending inmates' visits from relatives and friends and cutting back on elective medical appointments and outside work.

Inhibition of C5AR1 impairs osteoclast mobilization and prevents bone loss.

Age-related and chemotherapy-induced bone loss depends on cellular senescence and the cell secretory phenotype. However, the factors secreted in the senescent microenvironment that contribute to bone loss remain elusive. Here, we report a central role for the inflammatory alternative complement system in skeletal bone loss. Through transcriptomic analysis of bone samples, we identified complement factor D, a rate-limiting factor of the alternative pathway of complement, which is among the most responsive factors to chemotherapy or estrogen deficiency. We show that osteoblasts and osteocytes are major inducers of complement activation, while monocytes and osteoclasts are their primary targets. Genetic deletion of C5ar1, the receptor of the anaphylatoxin C5a, or treatment with a C5AR1 inhibitor reduced monocyte chemotaxis and osteoclast differentiation. Moreover, genetic deficiency or inhibition of C5AR1 partially prevented bone loss and osteoclastogenesis upon chemotherapy or ovariectomy. Altogether, these lines of evidence support the idea that inhibition of alternative complement pathways may have some therapeutic benefit in osteopenic disorders.

SUCNR1 signaling in adipocytes controls energy metabolism by modulating circadian clock and leptin expression.

Adipose tissue modulates energy homeostasis by secreting leptin, but little is known about the factors governing leptin production. We show that succinate, long perceived as a mediator of immune response and lipolysis, controls leptin expression via its receptor SUCNR1. Adipocyte-specific deletion of Sucnr1 influences metabolic health according to nutritional status. Adipocyte Sucnr1 deficiency impairs leptin response to feeding, whereas oral succinate mimics nutrient-related leptin dynamics via SUCNR1. SUCNR1 activation controls leptin expression via the circadian clock in an AMPK/JNK-C/EBPα-dependent manner. Although the anti-lipolytic role of SUCNR1 prevails in obesity, its function as a regulator of leptin signaling contributes to the metabolically favorable phenotype in adipocyte-specific Sucnr1 knockout mice under standard dietary conditions. Obesity-associated hyperleptinemia in humans is linked to SUCNR1 overexpression in adipocytes, which emerges as the major predictor of adipose tissue leptin expression. Our study establishes the succinate/SUCNR1 axis as a metabolite-sensing pathway mediating nutrient-related leptin dynamics to control whole-body homeostasis.

HERC1 deficiency causes osteopenia through transcriptional program dysregulation during bone remodeling.

Bone remodeling is a continuous process between bone-forming osteoblasts and bone-resorbing osteoclasts, with any imbalance resulting in metabolic bone disease, including osteopenia. The HERC1 gene encodes an E3 ubiquitin ligase that affects cellular processes by regulating the ubiquitination of target proteins, such as C-RAF. Of interest, an association exists between biallelic pathogenic sequence variants in the HERC1 gene and the neurodevelopmental disorder MDFPMR syndrome (macrocephaly, dysmorphic facies, and psychomotor retardation). Most pathogenic variants cause loss of HERC1 function, and the affected individuals present with features related to altered bone homeostasis. Herc1-knockout mice offer an excellent model in which to study the role of HERC1 in bone remodeling and to understand its role in disease. In this study, we show that HERC1 regulates osteoblastogenesis and osteoclastogenesis, proving that its depletion increases gene expression of osteoblastic makers during the osteogenic differentiation of mesenchymal stem cells. During this process, HERC1 deficiency increases the levels of C-RAF and of phosphorylated ERK and p38. The Herc1-knockout adult mice developed imbalanced bone homeostasis that presented as osteopenia in both sexes of the adult mice. By contrast, only young female knockout mice had osteopenia and increased number of osteoclasts, with the changes associated with reductions in testosterone and dihydrotestosterone levels. Finally, osteocytes isolated from knockout mice showed a higher expression of osteocytic genes and an increase in the Rankl/Opg ratio, indicating a relevant cell-autonomous role of HERC1 when regulating the transcriptional program of bone formation. Overall, these findings present HERC1 as a modulator of bone homeostasis and highlight potential therapeutic targets for individuals affected by pathological HERC1 variants.

Effect of strength training versus raloxifene on bone weight, blood glucose, lipid and antioxidant profile in ovariectomized rats

We compared the effect of the treatment with strength training (ST) and raloxifene (RALOX) on bone weight, blood glucose, lipid, and antioxidant profile in ovariectomized rats. Twenty-four Wistar rats were distributed into four groups: ovariectomy + VEHICLE (control); ovariectomy + RALOX; ovariectomy + ST; ovariectomy + RALOX + ST. Thirty days after ovariectomy, the animals underwent the treatment with RALOX (750 µcg day-1) and/or ST (three sessions week-1). Thirty days after, all groups were scarified, tibia and femur were weighed, and the blood was collected for analysis of the lipid profile, glucose, and antioxidants catalase (CAT) and glutathione (GSH). The ST group showed greater femur weight (0.82 ± 0.18 g) and RALOX + ST had greater tibia weight (0.61± 0.17 g) than CONTROL with femur weight of 0.65 ± 0.08 g and tibia of 0.49 ± 0.08 g with no differences between treatments (p > 0.05). ST group showed significantly higher catalase (181.7 ± 15.4 µM g-1) compared to the other groups. In contrast, the GSH value was lower in ST group (89.2 ± 8.1 µM g-1) compared to RALOX (175.9 ± 17.1 µM g-1) and RALOX + ST (162.8 ± 12.1 µM g-1), but the values of these two groups did not differ from CONTROL(115.3 ± 21.1 µM g-1). Total cholesterol did not differ between groups (p > 0.05), but exercise alone(54.3 ± 2.5 mg dL-1) or with RALOX (53.0 ± 1.5 mg dL-1) resulted in higher HDL cholesterol than CONTROL (45.5 ± 2.5 mg dL-1). Only RALOX+ST presented lower glucose (140.3 ± 9.7 mg dL-1) values than CONTROL (201.7 ± 30.6 mg dL-1). In conclusion, ST promotes similar benefits on bone and metabolic parameters compared to pharmacological treatment in ovariectomized rats.(AU)

Overview of SARS-COV-2 infection at the Butantan Penitentiary Progression Center / Panorama da infecção pelo SARS-COV-2 no Centro de Progressão Penitenciária do Butantan

ABSTRACT OBJECTIVE To estimate the prevalence of exposure to the SARS-CoV-2 virus among individuals living in restricted freedom. METHODS A seroprevalence survey was carried out with the population of the female penitentiary of the Centro de Progressão Penitenciária (CPP) in Butantan (municipality of São Paulo), between June 24 and August 20, 2020. During this period, according to the Secretariat of Penitentiary Administration (SAP), the positivity of rapid tests among inmates ranged from 65% to 78%. The evaluation method used in the study was the "One Step COVID-19" rapid test (chromatography), from the company Wondfo, also using the RT-PCR method in symptomatic participants to confirm the viral condition. The study population consisted of 879 female inmates and 170 employees of the institution. RESULTS The prevalence of total antibodies (IgG/IgM) against the SARS-CoV-2 virus in the total population of 1049 study participants was 6.1%; among the population of 879 inmates,a prevalence of 5.8% was observed, and among the institution's employees, 7.5%. CONCLUSIONS The prevalence of covid-19 at the Butantan CPP was low, which is due to the implementation of simple prevention measures at the institution, such as the use of masks (with appropriate changes), emphasis on hygiene, hand washing and social distancing, in addition to other strategies, such as suspending inmates' visits from relatives and friends and cutting back on elective medical appointments and outside work.

RESUMO OBJETIVO Estimar a prevalência da exposição ao vírus SARS-CoV-2 entre indivíduos vivendo em restrição de liberdade. MÉTODOS Foi realizado inquérito de soroprevalência com a população da penitenciária feminina do Centro de Progressão Penitenciária (CPP) do Butantan (município de São Paulo), entre 24 de junho e 20 de agosto de 2020. Nesse período, segundo a Secretaria de Administração Penitenciária (SAP), a positividade dos testes rápidos entre detentos variou de 65 a 78%. O método de avaliação utilizado no estudo foi o teste rápido "One Step COVID-19" (cromatografia), da empresa Wondfo, empregando-se também o método RT-PCR em participantes sintomáticos para confirmação do quadro viral. A população do estudo foi constituída por 879 reeducandas e 170 funcionários da instituição. RESULTADOS A prevalência de anticorpos totais (IgG/IgM) contra o vírus SARS-CoV-2 na população total de 1.049 participantes do estudo foi de 6,1%; entre a população de 879 reeducandas foi observada prevalência de 5,8% e entre os servidores da instituição, 7,5%. CONCLUSÃO Houve baixa prevalência de covid-19 no CPP do Butantan, o que se deve à implementação de medidas de prevenção simples na instituição, como o uso de máscaras (com trocas adequadas), ênfase na higiene, lavagem das mãos e distanciamento social, além de outras estratégias, como suspensão de visitas de familiares e amigos das reeducandas, cortes de consultas médicas eletivas e do trabalho externo.

Microfluidic production of mRNA-loaded lipid nanoparticles for vaccine applications.

INTRODUCTION: During past years, lipid nanoparticles (LNPs) have emerged as promising carriers for RNA delivery, with several clinical trials focusing on both infectious diseases and cancer. More recently, the success of messenger RNA (mRNA) vaccines for the treatment of severe diseases, such as acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is partially justified by the development of LNPs encapsulating mRNA for efficient cytosolic delivery. AREAS COVERED: This review examines the production and formulation of LNPs by using microfluidic devices, the status of mRNA-loaded LNPs therapeutics and explores spray drying process, as a promising dehydration process to enhance LNP stability and provide alternative administration routes. EXPERT OPINION: Microfluidic techniques for preparation of LNPs based on organic solvent injection method promotes the generation of stable, uniform, and monodispersed nanoparticles enabling higher encapsulation efficiency. In particular, the application of microfluidics for the fabrication of mRNA-loaded LNPs is based on rapid mixing of small volumes of ethanol solution containing lipids and aqueous solution containing mRNA. Control of operating parameters and formulation has enabled the optimization of nanoparticle physicochemical characteristics and encapsulation efficiency.

Role of TLR2/MyD88 in the production of specific IgM and IgG antibodies during the immunization of mice against Neospora caninum.

Neospora caninum is a parasite relevant to the veterinary field. Innate and adaptive responses against N. caninum induce effector mechanisms that limit parasite replication, but little is known about their role in humoral response. Our work aimed to verify whether key molecules in the TLR2/MyD88-mediated response would impact the production of specific IgM and IgG antibodies in mice during immunization with soluble antigens of N. caninum. We observed that lack of IFN-gamma did not negatively affect the production of specific antibodies. However, mice genetically deficient in Toll-like receptor 2, Myeloid differentiation factor 88, Interleukin 12 and inducible nitric oxide synthase presented significant decrease in antibody levels against N. caninum antigens, which also reflected in the diversity of the antigen recognized by their serum. In that sense, we show here that molecules within this innate recognition pathway may present a direct impact in the induction of an antibody response against N. caninum.

Nanoclay-reinforced HA/alginate scaffolds as cell carriers and SDF-1 delivery-platforms for bone tissue engineering.

Bone tissue engineering has come on the scene to overcome the difficulties of the current treatment strategies. By combining biomaterials, active agents and growth factors, cells and nanomaterials, tissue engineering makes it possible to create new structures that enhance bone regeneration. Herein, hyaluronic acid and alginate were used to create biologically active hydrogels, and montmorillonite nanoclay was used to reinforce and stabilize them. The developed scaffolds were found to be biocompatible and osteogenic with mMSCs in vitro, especially those reinforced with the nanoclay, and allowed mineralization even in the absence of differentiation media. Moreover, an in vivo investigation was performed to establish the potential of the hydrogels to mend bone and act as cell-carriers and delivery platforms for SDF-1. Scaffolds embedded with SDF-1 exhibited the highest percentages of bone regeneration as well as of angiogenesis, which confirms the suitability of the scaffolds for bone. Although there are a number of obstacles to triumph over, these bioengineered structures showed potential as future bone regeneration treatments.

Refractory CIDP successfully treated with autologous haematopoietic stem cell transplantation in a patient with monoclonal gammopathy of undetermined significance (MGUS) and rheumatoid arthritis.

Autologous haematopoietic stem cell transplantation is an emerging treatment option in refractory chronic inflammatory demyelinating polyradiculoneuropathy. We describe a case of a 46-year-old male, with history of IgG/lambda monoclonal gammopathy, who was diagnosed with chronic inflammatory demyelinating polyradiculoneuropathy at 27 years of age. After an initial 10-year period of corticotherapy response, the patient experienced severe relapses and disease progression, evolving to a refractory state. First-line and escalating treatment could not achieve clinical stabilization, leading to severe disability. Pre-treatment with ibrutinib was initiated and autologous haematopoietic stem cell transplantation was performed without significant complications. Marked clinical improvement was observed in the following months, both subjective and objective. A significant proportion of the patients who respond to the first-line immunosuppressive therapy eventually become treatment-refractory. Autologous haematopoietic stem cell transplantation may be a treatment option, offering long-term remission with an overall acceptable side effect and risk profile.

Prevalence of Antibodies to Toxoplasma gondii in Different Wild Bird Species Admitted to Rehabilitation Centres in Portugal.

Toxoplasma gondii is a worldwide zoonotic parasite. According to the "One Health" approach, studies on toxoplasmosis are essential since it affects humans and domestic and wild animals. In the present study, antibodies to T. gondii were determined in serum samples from 263 wild birds located in five wildlife rehabilitation centres in mainland Portugal by using the modified agglutination test (MAT) with a cut-off titre of 20. An overall seroprevalence of 36.5% (95% confidence interval [CI]: 30.7-42.6) was observed. For the first time, antibodies to T. gondii were detected in some avian species, including pallid swift (Apus pallidus) (33.3%), black-backed gull (Larus fuscus) (39.3%), European turtle-dove (Streptopelia turtur) (100%), bee-eater (Merops apiaster) (50.0%), carrion crow (Corvus corone) (33.3%), and Egyptian vulture (Neophron percnopterus) (100%), which expands the list of intermediate hosts of T. gondii. A lower seroprevalence was found in juvenile birds (31.9%) compared to adults (48.7%) (p = 0.016). The central region of Portugal was considered a risk factor for T. gondii infection in wild birds (odds ratio: 3.61; 95% CI: 1.09-11.91). This pioneer study calls attention to the need for further studies, to provide a clearer understanding of T. gondii epidemiology in Portugal, because it reflects wide dispersion of T. gondii oocysts in the environment.

Nanomechanical Phenotypes in Cardiac Myosin-Binding Protein C Mutants That Cause Hypertrophic Cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is a disease of the myocardium caused by mutations in sarcomeric proteins with mechanical roles, such as the molecular motor myosin. Around half of the HCM-causing genetic variants target contraction modulator cardiac myosin-binding protein C (cMyBP-C), although the underlying pathogenic mechanisms remain unclear since many of these mutations cause no alterations in protein structure and stability. As an alternative pathomechanism, here we have examined whether pathogenic mutations perturb the nanomechanics of cMyBP-C, which would compromise its modulatory mechanical tethers across sliding actomyosin filaments. Using single-molecule atomic force spectroscopy, we have quantified mechanical folding and unfolding transitions in cMyBP-C domains targeted by HCM mutations that do not induce RNA splicing alterations or protein thermodynamic destabilization. Our results show that domains containing mutation R495W are mechanically weaker than wild-type at forces below 40 pN and that R502Q mutant domains fold faster than wild-type. None of these alterations are found in control, nonpathogenic variants, suggesting that nanomechanical phenotypes induced by pathogenic cMyBP-C mutations contribute to HCM development. We propose that mutation-induced nanomechanical alterations may be common in mechanical proteins involved in human pathologies.

NRF2 function in osteocytes is required for bone homeostasis and drives osteocytic gene expression.

Osteocytes, the most abundant bone cell type, are derived from osteoblasts through a process in which they are embedded in an osteoid. We previously showed that nutrient restriction promotes the osteocyte transcriptional program and is associated with increased mitochondrial biogenesis. Here, we show that increased mitochondrial biogenesis increase reactive oxygen species (ROS) levels and consequently, NRF2 activity during osteocytogenesis. NRF2 activity promotes osteocyte-specific expression of Dmp1, Mepe, and Sost in IDG-SW3 cells, primary osteocytes, and osteoblasts, and in murine models with Nfe2l2 deficiency in osteocytes or osteoblasts. Moreover, ablation of Nfe2l2 in osteocytes or osteoblasts generates osteopenia and increases osteoclast numbers with marked sexual dimorphism. Finally, treatment with dimethyl fumarate prevented the deleterious effects of ovariectomy in trabecular bone masses of mice and restored osteocytic gene expression. Altogether, we uncovered the role of NRF2 activity in osteocytes during the regulation of osteocyte gene expression and maintenance of bone homeostasis.

Perspectivas sobre o lazer das mulheres com a pandemia do novo coronavírus reflexões a partir dos dados da pesquisa "O lazer no Brasil - representações e concretizações das vivências cotidianas" / Coronavirus pandemic: reflections based on the research data "Leisure in Brazil representations andconcretizations of everyday experiences"

O presente artigo busca refletir sobre práticas de lazer, mulheres e a pandemia do novo coronavírus, por meio de um diálogo analítico entre os dados da pesquisa "O Lazer no Brasil: representações e concretizações das vivências cotidianas" e investigações científicas recentes. A referida pesquisa teve como objetivo geral investigar as possibilidades de vivência do lazer da população brasileira. Este artigo, em específico, analisa as diferenças percebidas entre mulheres e homens, filtrando-se os dados pela condição empregatícia e pelo estado civil. Concluímos que a crise histórica instaurada pelo novo coronavírus tende a agravar de forma alarmante as condições sociais para a vivência do lazer de grupos em vulnerabilidade, como é o caso das mulheres.

This article intends to reflect on leisure practices, women and the pandemic caused by the new coronavirus, through an analytical dialogue between the data obtained in the research project entitled "Leisure in Brazil: representations and achievements of daily experiences" and recent scientific investigations. The referred research project inquired on leisure experiences of the Brazilian population. The present article analyzes the differences perceived between women andmen by filtering the sample by an individual's employment condition and by marital status. Our conclusion alerts that the historical crisis caused by the pandemic of the new coronavirus tends to alarmingly aggravate social conditions, such as access to leisure of vulnerable groups, such as women.

Serological evidence of Toxoplasma gondii infection in Melanosuchus niger (Spix, 1825) and Caimam crocodilus (Linnaeus, 1758).

Toxoplasma gondii is a protozoan with worldwide prevalence, known to affect a large variety of warm-blooded hosts. However, its ability to induce long-lasting infections in cold-blooded animals remains unclear. The most likely source of infection is through consumption of meat containing tissue cysts or by ingestion of food or water contaminated with oocysts. The current global climate change trend and the progressive degradation of natural habitats are prone to alter the distribution of ectotherm populations over a short period of time, which may favor contact between these animals and the protozoan. In association, alligator meat is considered a delicacy in many regions and its consumption has been previously related to a diversity of foodborne diseases. In that sense, we proposed in this study to search for specific antibodies against T. gondii in serum samples of two common species of alligators from the Brazilian fauna (Melanosuchus niger and Caimam crocodilus). We obtained the serum samples from 84 alligators from the Araguaia region, which were tested by agglutination assays that do not require species-specific secondary antibodies (Modified Agglutination Test - MAT; Indirect Hemagglutination Assay - IHA). From the 84 samples tested, eight (9.5%) were positive by MAT. From those, seven (87.5% of MAT+, 8.3% of the total) were also positive by IHA, reassuring a probable exposure of these animals to the parasite. Direct parasite detection in muscle fragments of one serologically reactive alligator did not yield positive results. Our results provide serological evidence that Brazilian alligators may be exposed to T. gondii and further studies should be performed to elucidate whether alligators are natural hosts of this ubiquitous protozoan parasite.