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Hemotropic mycoplasmas are bacteria that attaches to erythrocytes surface, which some species presents zoonotic concerns. In the suborder Pinnipedia, genera Otaria and Arctocephalus are prominent in Brazil. This study investigated the occurrence of hemoplasmas in Arctocephalus sp. and Otaria flavescens found dead along the coast of a Southern Brazilian State. DNA from 135 spleen samples were extracted and subjected to conventional PCR protocols, targeting the 16 S rRNA and 23 S rRNA gene. Three (2.22 %) Arctocephalus australis were positive in the 16 S rRNA gene, and no samples amplified in the 23 S rRNA gene. Samples from this study clustered with Zalophus californianus and Arctocephalus tropicalis mycoplasmas on a Bayesian phylogenetic analysis. Genetic diversity analysis suggested distinct genotypes, indicating A. australis as a new host for hemoplasma, and also a potential putative novel hemoplasma genotype. These findings raises future awareness for pinnipeds conservation, and adds Mycoplasma spp. to be taken into consideration when clinically evaluating rescued animals., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Among vector-borne helminths, filarioids of the genus Dipetalonema (Spirurida: Onchocercidae) localize in several tissues and body cavities of several animal species, causing mild to moderate lesions. The pathological findings associated with Dipetalonema spp. infection in Neotropical monkeys from southern Brazil are herein described, along with a fatal case due to filarial polyserositis and entrapment of an intestinal segment. At necropsy, nematodes were observed in abdominal and thoracic cavities, or in the pericardium of 37 (31.3%) out of the 118 individuals examined (i.e., 35 Alouatta guariba clamitans and two Sapajus nigritus). In addition, at histology, 27.0% of positive animals presented microfilarie (inside blood vessels of lung, spleen, liver, and brain) and 8.1% presented adult nematodes in the heart, lung, and liver. In two cases, cross-sections of filarioids were associated with areas of epicardial thickening with intense fibrosis and pyogranulomatous inflammation in the brain, heart, liver, lungs, or spleen. The DNA fragment was amplify using the cox1 gene, sequenced and analyzed to identify the nematode species collected; presence of Wolbachia was assessed in the filarioids using the 16S rRNA gene. At BLAST analysis of the cox1 gene, 10 sequences showed 91.7% nucleotide identity with Dipetalonema gracile, and two with D. gracile (98.5%) and Dipetalonema graciliformis (98.3%). Phylogenetic analyses clustered sequences of the cox1 obtained in this study in two clades corresponding with the host species. Wolbachia sp. endosymbiont was detected in four samples. Data herein reported provide a description of pathological lesions associated with the infection by Dipetalonema spp., suggesting that they may cause disease in Neotropical monkeys. In addition, a better understanding of diversity and biology of Dipetalonema spp. in South America is needed to assess the impact they may cause in native non-human primates from Brazil., (© 2023. The Author(s).)

Hemoplasmas are non-cultivable bacterial parasites of erythrocytes that infect domestic and wild animals, as well as humans. Their means of transmission and pathogenesis remain contentious issues and difficult to evaluate in wild animals. Procyon cancrivorus is a South American carnivore and occurs in all Brazilian biomes. In this study, we aimed to investigate occurrences of hemoplasmas infecting P. cancrivorus and to identify their 16S rRNA gene, in southern Brazil. DNA was extracted from spleen and blood samples of P. cancrivorus (n = 9) from different locations. Hemoplasma DNA was detected in six samples, based on 16S rRNA gene amplification and phylogenetic analysis. Four of the six sequences belonged to the "Mycoplasma haemofelis group", which is closely related to genotypes detected in Procyon lotor from the USA; one was within the "Mycoplasma suis group", closely related to "Candidatus Mycoplasma haemominutum"; and one was within the intermediate group between these clusters. Thus, these sequences showed that the molecular identity of hemoplasmas in the population studied was very variable. In five positive animals, Amblyomma aureolatum ticks and a flea (Ctenocephalides felis felis) were collected. The present study describes the first molecular detection of mycoplasmas in P. cancrivorus.

Mansonellosis is a neglected and emerging tropical disease. Among all zoonotic filarial diseases, it is probably the most prevalent and least studied, with approximately 114 million people infected. The parasites of Mansonella spp. are among the most common blood parasitemias and are widely found in Africa and Latin America. Through molecular analysis of blood samples from free-ranging primates Sapajus nigritus (n 33) and Alouatta guariba clamitans (n 5) in the southern states of Brazil (Santa Catarina and Rio Grande do Sul), we identified samples positive for Mansonella perstans in two specimens of A. guariba clamitans. A fragment of 578 bp from the ITS intergenic region (5.8S-ITS2-28S) was targeted for an initial PCR screening. Subsequently, positive samples were subjected to other PCR assays targeting a fragment of the 12S and the 18S genes. This is the first record of molecular detection of the agent in this host in the Pampa Biome. With a wide distribution across Brazil and Argentina, these primates may represent a potential wild reservoir for the zoonotic agent of mansonellosis. Entomological and transmission studies are essential to avoid the urbanization of mansonellosis and to understand the cycles of agents in different environmental scenarios., (© 2022. The Author(s), under exclusive licence to Japan Monkey Centre.)

Background: Tungiasis is a neglected neotropical disease caused by penetration of Tunga spp. into the skin of the host., Methods: Two primates were rescued from nearby different indigenous villages, and the clinical, pathological, and parasitological features of tungiasis were described. Flea identification occurred through their morphometry and was confirmed with the use of a dichotomous key., Results: Monkey 1 was parasitized by 23 sand fleas and, after treatment, was assigned to the animal rehabilitation center. Monkey 2 was in poor body condition and died shortly after clinical examination. At necropsy, this primate was parasitized by 26 specimens of sand fleas., Conclusions: Both animals altered their tree behavior by staying on the ground for long periods. This parasitic relationship implies the possibility of enlargement of the sand flea dispersion. Thus, this is the first record of Tunga penetrans occurrence in wild Alouatta guariba clamitans., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

A comparative venom proteomic analysis of the Brazilian southern coral snake, M. frontalis, the Amazon coral snake M. spixii spixii, and the aquatic coral snake M. surinamensis is reported. Venoms from M. frontalis and M. s. spixii were composed mainly (>90% of the total venom proteome) by 3FTxs and PLA 2 s in different proportions, and minor proteins from 2 to 5 protein families. Conversely, the aquatic coral snake expressed a streamlined (95%) 3FTx venom with low abundance (4.2%) of PLA 2 molecules. A compositional-lethal activity for natural prey correlation analysis suggests that M. surinamensis venom may has evolved under strong pressure to quickly immobilize aquatic prey. On the other hand, venoms from M. frontalis and M. s. spixii, whose diet consist mainly of amphisbaenians and colubrid snakes, may have been shaped through balancing selection. Our work provides strong evidence for the occurrence in M. frontalis venom, but not in those from M. s. spixi and M. surinamensis, of a KUN-PLA 2 complex homologue to heterodimeric venom toxins from some long-tailed monadal coral snakes that target acid-sensing receptors ASIC1a/2 evoking pain. The M. frontalis protein would represent the first example of a KUN-PLA 2 heterodimer in a South American short-tailed triadal coral snake venom., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Canine rangeliosis is a tick-borne disease caused by the protozoan Rangelia vitalii, which has only been reported in South America. With this knowledge, we hypothesized that neotropical foxes could act as asymptomatic natural carriers of R. vitalii. To test this, we captured 44 free-ranging foxes and investigated the presence of R. vitalii DNA, and whether the infected animals presented any clinical findings or hematological changes. Eight foxes (18%), seven Cerdocyon thous (7/27-25%), and one Lycalopex gymnocercus (1/17-5%) were positive for R. vitalii. All foxes were clinically healthy and showed no hematological abnormalities. Thus, we propose that neotropical canids, particularly C. thous, could be the natural carriers of R. vitalii.

We use energy landscape methods to investigate the response of a supercooled liquid to random pinning. We classify the structural similarity of different energy minima using a measure of overlap. This analysis reveals a correspondence between distinct particle packings (which are characterised via the overlap) and funnels on the energy landscape (which are characterised via disconnectivity graphs). As the number of pinned particles is increased, we find a crossover from glassy behavior at low pinning to a structure-seeking landscape at high pinning, in which all thermally accessible minima are structurally similar. We discuss the consequences of these results for theories of randomly pinned liquids. We also investigate how the energy landscape depends on the fraction of pinned particles, including the degree of frustration and the evolution of distinct packings as the number of pinned particles is reduced.

We study the dynamical behaviour of a computer model for viscous silica, the archetypal strong glass former, and compare its diffusion mechanism with earlier studies of a fragile binary Lennard-Jones liquid. Three different methods of analysis are employed. First, the temperature and time scale dependence of the diffusion constant is analysed. Negative correlation of particle displacements influences transport properties in silica as well as in fragile liquids. We suggest that the difference between Arrhenius and super-Arrhenius diffusive behaviour results from competition between the correlation time scale and the caging time scale. Second, we analyse the dynamics using a geometrical definition of cage-breaking transitions that was proposed previously for fragile glass formers. We find that this definition accurately captures the bond rearrangement mechanisms that control transport in open network liquids, and reproduces the diffusion constants accurately at low temperatures. As the same method is applicable to both strong and fragile glass formers, we can compare correlation time scales in these two types of systems. We compare the time spent in chains of correlated cage breaks with the characteristic caging time and find that correlations in the fragile binary Lennard-Jones system persist for an order of magnitude longer than those in the strong silica system. We investigate the origin of the correlation behaviour by sampling the potential energy landscape for silica and comparing it with the binary Lennard-Jones model. We find no qualitative difference between the landscapes, but several metrics suggest that the landscape of the fragile liquid is rougher and more frustrated. Metabasins in silica are smaller than those in binary Lennard-Jones and contain fewer high-barrier processes. This difference probably leads to the observed separation of correlation and caging time scales.

The emergence of observable properties from the organisation of the underlying potential energy landscape is analysed, spanning a full range of complexity from self-organising to glassy and jammed systems. The examples include atomic and molecular clusters, a β-barrel protein, the GNNQQNY peptide dimer, and models of condensed matter that exhibit structural glass formation and jamming. We have considered measures based on several different properties, namely, the Shannon entropy, an equilibrium thermodynamic measure that uses a sample of local minima, and indices that require additional information about the connections between local minima in the form of transition states. A frustration index is defined that correlates directly with key properties that distinguish relaxation behaviour within this diverse set. The index uses the ratio of the energy barrier to the energy difference with reference to the global minimum. The contributions for each local minimum are weighted by the equilibrium occupation probabilities. Hence we obtain fundamental insight into the connections and distinctions between systems that cover the continuum from efficient structure-seekers to landscapes that exhibit broken ergodicity and rare event dynamics.

Relaxation times and transport processes of many glass-forming supercooled liquids exhibit a super-Arrhenius temperature dependence. We examine this phenomenon by computer simulation of the Lewis-Wahnström model for ortho-terphenyl. We propose a microscopic definition for a single-molecule cage-breaking transition and show that, when correlation behaviour is taken into account, these rearrangements are sufficient to reproduce the correct translational diffusion constants over an intermediate temperature range in the supercooled regime. We show that super-Arrhenius behaviour can be attributed to increasing negative correlation in particle movement at lower temperatures and relate this to the cage-breaking description. Finally, we sample the potential energy landscape of the model and show that it displays hierarchical ordering. Substructures in the landscape, which may correspond to metabasins, have boundaries defined by cage-breaking transitions. The cage-breaking formulation provides a direct link between the potential energy landscape and macroscopic diffusion behaviour.

Introduction: Toxoplasma gondii infection is widely prevalent in humans and other animals worldwide. Information on the prevalence of T. gondii infection is scarce in some regions of Brazil, including riverside communities along the Amazon River basin., M Methods: The prevalence of T. gondii in 231 people, aged 1-85 years, who were living in four riverside communities along the Purus River, Lábrea, State of Amazonas, Brazil, was determined. Antibodies against T. gondii were assayed using a commercial enzyme-linked immunosorbent assay (ELISA) kit. The hearts and brains of 50 chickens, which were raised free-range in the communities, were pooled according to the community of origin and bioassayed in mice. The isolates were genotyped using polymorphisms at 12 nuclear markers (SAG1, 5' and 3'-SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, Apico and CS3)., Results: The overall seroprevalence of T. gondii was 56.7% (131/231). IgG antibodies were presented by 117 (89.3%) and IgM by 14 (10.7%) of the 131 positive individuals. No association between age group and gender with prevalence was observed (chi-square test, p > 0.05); however, the comparison between localities showed that the seroprevalence of T. gondii was significantly lower among the individuals living in the Boca do Ituxi (p < 0.05) community. Five isolates of T. gondii were obtained in the mouse bioassay, and genotyping revealed two complete genotypes that had not been described previously and three mixed isolates., Conclusions: These results support previous findings that T. gondii population genetics are highly diverse in Brazil and that T. gondii infection is active in these riverside communities.

The structure and available degrees of freedom of an amorphous configuration can determine the location of dynamic heterogeneities. In the same way, these features can also determine the directionality of the particle motion. In this paper we propose that directionality can be attributed to those particles that only participate in a single unconstrained motion. The consequences of this suggestion in terms of the spatial distribution of particles with high directionality are explored using a random bond model.

It is proposed that the dynamic heterogeneities of an amorphous material are strongly correlated with the spatial distribution of unconstrained degrees of freedom in the associated network of mechanical constraints. This latter distribution is shown to depend sensitively on whether or not overconstraints are permitted in the constraint network. When overconstraints are avoided, relaxation is achieved with few bond rearrangements and the susceptibility χ(4) increases monotonically with increasing constraint density, in contrast to the case of a random network. This behaviour is associated with the marginal stability of the isostatic rigid cluster as opposed to the more robust structures generated when redundant bonds are permitted.

In trypanosomatids, Ca²+-binding proteins can affect parasite growth, differentiation and invasion. Due to their importance for parasite maintenance, they become an attractive target for drug discovery and design. Phytomonas serpens 15T is a non-human pathogenic trypanosomatid that expresses important protein homologs of human pathogenic trypanosomatids. In this study, the coding sequence of calmodulin, a Ca²+-binding protein, of P. serpens 15T was cloned and characterized. The encoded polypeptide (CaMP) displayed high amino acid identity to homolog protein of Trypanosoma cruzi and four helix-loop-helix motifs were found. CaMP sequence analysis showed 20 amino acid substitutions compared to its mammalian counterparts. This gene is located on a chromosomal band with estimated size of 1,300 kb and two transcripts were detected by Northern blot analysis. A polyclonal antiserum raised against the recombinant protein recognized a polypeptide with an estimated size of 17 kDa in log-phase promastigote extracts. The recombinant CaMP retains its Ca²+-binding capacity.

We describe a random bond network with fluctuating mechanical constraints for which structural and dynamical length scales are explicitly defined and can be compared with the observable properties of the system. The constraints give well-defined individual structures, describing rigid clusters of particles, and there are distinct structural changes between different configurations. In addition, unambiguous unconstrained motions, including extended collective motions, can be defined within each configuration of constraints. By considering fluctuations of bonds in the network, we can analyze the relaxation of a simple model amorphous material subject to randomly arranged mechanical constraints. The lengths of the collective motions are obtained directly and compared with both the relaxation kinetics and the susceptibility χ(4). Above percolation, the latter quantity is shown to decrease with increasing degree of constraint, a behavior linked, in this paper, to the presence of overconstraint in the network at bond densities beyond the percolation point. Our model system, despite a propensity for highly collective motions, shows that an increasing timescale for relaxation can be accompanied by a decreasing χ(4).

The genus Phytomonas comprises trypanosomatids that can parasitize a broad range of plant species. These flagellates can cause diseases in some plant families with a wide geographic distribution, which can result in great economic losses. We have demonstrated previously that Phytomonas serpens 15T, a tomato trypanosomatid, shares antigens with Trypanosoma cruzi, the agent of human Chagas disease. Herein, two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS) were used to identify proteins of P. serpens 15T that are recognized by sera from patients with Chagas disease. After 2D-electrophoresis of whole-cell lysates, 31 peptides were selected and analyzed by tandem mass spectrometry. Twenty-eight polypeptides were identified, resulting in 22 different putative proteins. The identified proteins were classified into 8 groups according to biological process, most of which were clustered into a cellular metabolic process category. These results generated a collection of proteins that can provide a starting point to obtain insights into antigenic cross reactivity among trypanosomatids and to explore P. serpens antigens as candidates for vaccine and immunologic diagnosis studies.

A disordered network of bonds with a fixed configuration can relax via a variety of unconstrained motions. These motions can be directly inferred from the topological arrangement of constraints without any geometrical information. We use the pebble game algorithm of Jacobs and Thorpe [D. J. Jacobs and M. F. Thorpe, Phys. Rev. Lett. 75, 4051 (1995)] to decompose the system into separate rigid clusters and identify the remaining degrees of freedom. Unconstrained motions can then be resolved in the form of translations and rotations of isolated groups of bonds and the internal motion within bond groups. We show that each motion can be assigned a characteristic thermal velocity and hence a relaxation time scale. We use this information to construct a relaxation function and also examine the spatial distribution of relaxation time scales. We investigate the sensitivity of the relaxation time scales and their spatial distribution when making individual bond changes in the system, and we consider the dependence of these time scales on the underlying structure.

We show how the spatial character of unconstrained motion in a network of bonds can be directly inferred from the topological arrangement of constraints. Relaxation time scales of these soft modes are determined, and from this information we generate spatial maps of the heterogeneous distribution of relaxation times in the disordered network. We show that the nature of the dynamic heterogeneity and its sensitivity to changes in bond configuration depends dramatically on the proximity of the system to the rigidity percolation point.

Connectivity in the potential energy landscape of a binary Lennard-Jones system can be characterized at the level of cage-breaking. We calculate the number of cage-breaking routes from a given local minimum and determine the branching probabilities at different temperatures, along with correlation factors that represent the repeated reversals of cage-breaking events. The number of reversals increases at lower temperatures and for more fragile systems, while the number of accessible connections decreases. We therefore associate changes in connectivity with super-Arrhenius behavior. Reversals in minimum-to-minimum transitions are common, but often correspond to "non-cage-breaking" processes. We demonstrate that the average waiting time within a minimum shows simple exponential behavior with decreasing temperature. To describe the long-term behavior of the system, we consider reversals and connectivity in terms of the "cage-breaking" processes that are pertinent to diffusion [V. K. de Souza and D. J. Wales, J. Chem. Phys. 129, 164507 (2008)]. These cage-breaking events can be modeled by a correlated random walk. Thus, a full correlation factor can be calculated using short simulations that extend up to two cage-breaking events.

A wide spectrum of potential energy barriers exists for binary Lennard-Jones systems. Here we examine the barriers and cage-breaking rearrangements that are pertinent to long-term diffusion. Single-step cage-breaking processes, which follow high-barrier routes, are identified, and different methods and criteria for defining a cage-breaking process are considered. We examine the extent to which a description of cage-breaking within the energy landscape is a description of long-term diffusion. This description includes the identification of cage-breaks that are reversed, and those that are productive towards long-term diffusion. At low temperatures, diffusion is adequately described by productive cage-breaks, or by considering all cage-breaks and accounting for the effect of reversals. To estimate the diffusion constant we require only the mean square displacement of a cage-break, the average waiting time for a cage-break, and a measure of the number of reversed cage-breaks. Cage-breaks can be visualized within the potential energy landscape using disconnectivity graphs, and we compare the use of productive cage-breaks with previous definitions of "megabasins" or "metabasins."

Prostaglandins are known to be produced by macrophages when challenged with Trypanosoma cruzi, the etiological agent of Chagas' disease. It is not known whether these lipid mediators play a role in oxidative stress in host defenses against this important protozoan parasite. In this study, we demonstrated that inducible cyclooxygenase-mediated prostaglandin production is a key chemical mediator in the control of parasite burden and erythrocyte oxidative stress during T. cruzi infection in C57BL/6 and BALB/c mice, prototype hosts for the study of resistance and susceptibility in murine Chagas' disease. The results suggested the existence of at least two mechanisms of oxidative stress, dependent or independent with regard to the nitric oxide and cyclooxygenase pathway, where one or the other is more evident depending on the mouse strain.

This paper presents an analysis of the thermodynamics of a model glass former. We have performed equilibrium sampling of a popular binary Lennard-Jones model, employing parallel tempering Monte Carlo to cover the crystalline, amorphous, and liquid regions of configuration space. Disconnectivity graphs are used to visualize the potential energy landscape in the vicinity of a crystalline geometry and in an amorphous region of configuration space. The crystalline global minimum is separated from the bulk of the minima by a large potential energy gap, leading to broken ergodicity in conventional simulations. Our sampling reveals crystalline global minima that are lower in potential energy than some of the previous candidates. We present equilibrium thermodynamic properties based on parallel tempering simulations, including heat capacities and free energy profiles, which depend explicitly on the crystal structure. We also report equilibrium melting temperatures.

The purpose of this work was to determine the most common anatomic location of bovine cysticercosis, as well as its number per animal. To accomplish these objectives a number of 26,633 bovines from the slaughterhouse Argus Ltd., SIF 1710, located at São José dos Pinhais in the State of Paraná, Brazil, were examined from July to December 2000. The results demonstrated that the head's muscles were infected with a rate of 57.77%, and the cardiac muscles 39.65%, totalizing 97.42% of the infected sites. According to the classification concerning viability, the occurrence of metacestode was 66.97% nonviable (dead) and 33.02% viable (alive). From the Cysticercus alive, 81% of them were located in the head's muscles and 17% in the heart; whereas from those dead, 52.11% were located in the heart's muscles and 47.88% in the hea's one. Of the total of carcasses positives for Cysticercus bovis, 94% of them were infected by only one cyst and 6% by multiple cysts. All the viable cysts were submitted to the morphologic identification being verified that 100% of the parasites were C. bovis.

On short time scales an underlying Arrhenius temperature dependence of the diffusion constant can be extracted from the fragile, super-Arrhenius diffusion of a binary Lennard-Jones mixture. This Arrhenius diffusion is related to the true super-Arrhenius behavior by a factor that depends on the average angle between steps in successive time windows. The correction factor accounts for the fact that on average, successive displacements are negatively correlated, and this effect can therefore be linked directly with the higher apparent activation energy for diffusion at low temperature.

The Mountain and Thirumalai energy fluctuation metric, Omega(t), has been used to study the effective ergodicity of 60- and 256-atom binary Lennard-Jones mixtures in order to determine the reliability of the calculated diffusion constants at different energies. A plot of Omega(t) against 1time allows the identification of two distinct regimes: ergodic supercooled liquids, where Omega(t) approaches zero, and nonergodic glassy states, where Omega(t) asymptotically approaches a nonzero value on the molecular dynamics time scale. This approach seems to be more appropriate than attempting to define a threshold value for Omega(t)/Omega(0). The behavior of systems between these two limits, which are nonergodic on the time scale considered but may be approaching ergodicity, was examined for a range of simulation times. The calculated diffusion constants change as effective ergodicity is approached, moving closer to the Vogel-Tammann-Fulcher fit defined by higher-energy systems that are already considered to be effectively ergodic. Using the form of the decay of the metric as a measure of ergodicity, we have been able to reproduce the trend in fragility obtained by Sastry for a 256-atom system [Nature (London) 409, 164 (2001)], correcting some of our earlier results [J. Chem. Phys. 120, 8314 (2004)].

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