Search Results (726)

Biofilms are a spontaneously formed slimy matrix of extracellular polymeric substances (EPS) enveloping miniature bacterial colonies, which aid in pathogen colonization, shielding the bacteria from antibiotics, as well as imparting them resistance towards the same. Biofilms employ a robust communication mechanism called quorum sensing that serves to keep their population density constant. What is most significant about biofilms is that they contribute to the development of bacterial virulence by providing protection to pathogenic species, allowing them to colonize the host, and also inhibiting the activities of antimicrobials on them. They grow on animate surfaces (such as on teeth and intestinal mucosa, etc.) and inanimate objects (like catheters, contact lenses, pacemakers, endotracheal devices, intrauterine devices, and stents, etc.) alike. It has been reported that as much as 80% of human infections involve biofilms. Serious implications of biofilms include the necessity of greater concentrations of antibiotics to treat common human infections, even contributing to antimicrobial resistance (AMR), since bacteria embedded within biofilms are protected from the action of potential antibiotics. This review explores various contemporary strategies for controlling biofilms, focusing on their modes of action, mechanisms of drug resistance, and innovative approaches to find a solution in this regard. This review interestingly targets the extracellular polymeric matrix as a highly effective strategy to counteract the potential harm of biofilms since it plays a critical role in biofilm formation and significantly contributes to antimicrobial resistance. Full article

This review presents a comprehensive overview of various ultrasound imaging techniques employed in the evaluation of the canine knee joint. It critically analyzes studies conducted on both human and animal subjects, with a focus on the diagnostic accuracy of B-mode ultrasound, Doppler examination, contrast-enhanced ultrasound, and elastography in both normal and pathological conditions. The review underscores the necessity of strict adherence to the protocols of each ultrasound modality and emphasizes the importance of a thorough understanding of the anatomical region to achieve optimal outcomes. The findings suggest that these ultrasound techniques can significantly enhance the diagnostic process, providing valuable insights into anatomy, size, blood supply, and tissue elasticity. Additionally, in cases where advanced imaging modalities such as computed tomography (CT) or magnetic resonance imaging (MRI) are cost-prohibitive or less accessible, ultrasound serves as a reliable alternative, delivering high diagnostic accuracy and critical information regarding mechanical changes in the joint and neovascularization. Full article

Many vertebrates have evolved resistance to snake venom as a result of coevolutionary chemical arms races. In Australian skinks (family Scincidae), who often encounter venomous elapid snakes, the frequency, diversity, and molecular basis of venom resistance have been unexplored. This study investigated the evolution of neurotoxin resistance in Australian skinks, focusing on mutations in the muscle nicotinic acetylcholine receptor (nAChR) α1 subunit’s orthosteric site that prevent pathophysiological binding by α-neurotoxins. We sampled a broad taxonomic range of Australian skinks and sequenced the nAChR α1 subunit gene. Key resistance-conferring mutations at the toxin-binding site (N-glycosylation motifs, proline substitutions, arginine insertions, changes in the electrochemical state of the receptor, and novel cysteines) were identified and mapped onto the skink organismal phylogeny. Comparisons with other venom-resistant taxa (amphibians, mammals, and reptiles) were performed, and structural modelling and binding assays were used to evaluate the impact of these mutations. Multiple independent origins of α-neurotoxin resistance were found across diverse skink lineages. Thirteen lineages evolved at least one resistance motif and twelve additional motifs evolved within these lineages, for a total of twenty-five times of α-neurotoxic venoms resistance. These changes sterically or electrostatically inhibit neurotoxin binding. Convergent mutations at the orthosteric site include the introduction of N-linked glycosylation sites previously known from animals as diverse as cobras and mongooses. However, an arginine (R) substitution at position 187 was also shown to have evolved on multiple occasions in Australian skinks, a modification previously shown to be responsible for the Honey Badger’s iconic resistance to cobra venom. Functional testing confirmed this mode of resistance in skinks. Our findings reveal that venom resistance has evolved extensively and convergently in Australian skinks through repeated molecular adaptations of the nAChR in response to the enormous selection pressure exerted by elapid snakes subsequent to their arrival and continent-wide dispersal in Australia. These toxicological findings highlight a remarkable example of convergent evolution across vertebrates and provide insight into the adaptive significance of toxin resistance in snake–lizard ecological interactions. Full article

Hair, as a non-invasive biospecimen, retains metabolic deposits from sebaceous glands and capillaries, reflecting substances from the peripheral circulation, and provides valuable biochemical information linked to phenotypes, yet its application in animal disease research remains limited. This work applied ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS) to compare the hair metabolomic characteristics of healthy forest musk deer (FMD, Moschus berezovskii) and those diagnosed with hemorrhagic pneumonia (HP), phytobezoar disease (PD), and abscess disease (AD). A total of 2119 metabolites were identified in the FMD hair samples, comprising 1084 metabolites in positive ion mode and 1035 metabolites in negative ion mode. Differential compounds analysis was conducted utilizing the orthogonal partial least squares–discriminant analysis (OPLS-DA) model. In comparison to the healthy control group, the HP group displayed 85 upregulated and 92 downregulated metabolites, the PD group presented 124 upregulated and 106 downregulated metabolites, and the AD group exhibited 63 upregulated and 62 downregulated metabolites. Functional annotation using the Kyoto Encyclopedia of Genes and Genomes (KEGG) indicated that the differential metabolites exhibited significant enrichment in pathways associated with cancer, parasitism, energy metabolism, and stress. Receiver operating characteristic (ROC) analysis revealed that both the individual and combined panels of differential metabolites exhibited area under the curve (AUC) values exceeding 0.7, demonstrating good sample discrimination capability. This research indicates that hair metabolomics can yield diverse biochemical insights and facilitate the development of non-invasive early diagnostic techniques for diseases in captive FMD. Full article

Thoracic injuries account for a high percentage of combat casualty mortalities, with 80% of preventable deaths resulting from abdominal or thoracic hemorrhage. An effective method for detecting and triaging thoracic injuries is point-of-care ultrasound (POCUS), as it is a cheap and portable noninvasive imaging method. POCUS image interpretation of pneumothorax (PTX) or hemothorax (HTX) injuries requires a skilled radiologist, which will likely not be available in austere situations where injury detection and triage are most critical. With the recent growth in artificial intelligence (AI) for healthcare, the hypothesis for this study is that deep learning (DL) models for classifying images as showing HTX or PTX injury, or being negative for injury can be developed for lowering the skill threshold for POCUS diagnostics on the future battlefield. Three-class deep learning classification AI models were developed using a motion-mode ultrasound dataset captured in animal study experiments from more than 25 swine subjects. Cluster analysis was used to define the “population” based on brightness, contrast, and kurtosis properties. A MobileNetV3 DL model architecture was tuned across a variety of hyperparameters, with the results ultimately being evaluated using images captured in real-time. Different hyperparameter configurations were blind-tested, resulting in models trained on filtered data having a real-time accuracy from 89 to 96%, as opposed to 78–95% when trained without filtering and optimization. The best model achieved a blind accuracy of 85% when inferencing on data collected in real-time, surpassing previous YOLOv8 models by 17%. AI models can be developed that are suitable for high performance in real-time for thoracic injury determination and are suitable for potentially addressing challenges with responding to emergency casualty situations and reducing the skill threshold for using and interpreting POCUS. Full article

Dietary protein levels greatly influence gut microbial ecosystems; however, their effects on gut archaea and associated functions in ruminants require further elucidation. This study evaluated the impact of varying dietary protein levels on gut archaeal composition, antimicrobial resistance (AMR) genes, virulence factors, and functional capacities in sheep. Eighteen ewes (Yunnan semi-fine wool breed, uniparous, 2 years old, and averaging 50 ± 2 kg body weight) were randomly assigned to diets containing an 8.5 (low; H_1), 10.3 (medium; H_m), or 13.9% (high; H_h) crude protein level from the 35th day of pregnancy to the 90th day postpartum. The total duration of the experiment was approximately 202 days. A total of nine fecal samples (three from each group) were analyzed via 16S rRNA and metagenomics sequencing. Higher archaeal alpha diversity and richness were observed in the H_m and H_h groups compared to the H_l group (p < 0.05). A Beta diversity analysis revealed the archaeal community’s distinct clustering mode based on protein levels. The methanogenic genera Methanobrevibacter and Methanocorpusculum were dominant across the three groups, and their abundance was influenced by protein intake. A functional prediction analysis indicated moderate changes in amino acid and carbohydrate metabolism, which are particularly associated with methane production, an important source of greenhouse gases. AMR genes (e.g., tetA (60), patA, vat, and Erm methyltransferase) and virulence factors (Bacillibactin, LPS) were significantly enriched when animals were fed high-protein diets. Our results demonstrated that dietary protein levels significantly influence gut archaeal composition, AMR gene enrichment, and related functional pathways. Medium-protein diets promoted greater archaeal diversity, whereas high-protein diets favored resistance gene proliferation and enhanced methanogenic activity. Optimizing dietary protein intake may enhance gut health, mitigate antimicrobial resistance risk, and reduce methane emissions, thereby supporting livestock sustainability and environmental protection. Full article

This study aimed to identify the heat-resistant bioactive components of Enterococcus faecium HDRsEf1 (HDRsEf1) and investigate their beneficial mechanism. Heat-treated culture supernatants of HDRsEf1 significantly suppressed CXCL-1 expression in LPS-stimulated MODE-K cells (p < 0.001), indicating the presence of heat-resistant anti-inflammatory components. Crude protein (P-Ef1) and crude expolysaccharide (EPS-Ef1) were isolated from an HDRsEf1 culture supernatant using ammonium sulfate and ethanal precipitation. Critically, only crude EPS-Ef1 retained an anti-inflammatory effect after heat treatment, while crude P-Ef1 lost this activity. Further investigation revealed that crude EPS-Ef1 (25 μg/mL) promoted MODE-K cell proliferation via EdU assays (p < 0.001), potentially through an upregulation of PCNA mRNA expression (p < 0.001). Animal studies demonstrated that an oral administration of crude EPS-Ef1 (4 mg/kg bw, 14 days) significantly increased body weight gain and jejunal crypt depth (p < 0.05) while reducing intestinal CXCL-1 mRNA levels (p < 0.001). These in vivo findings are consistent with in vitro observations. A structural analysis using HPAEC and SEC-MALLS-RI characterized crude EPS-Ef1 as a heteropolysaccharide (Mw 80.3 kDa) with a near-spherical conformation (slope 0.13) composed of mannose, glucose, glucuronic acid, and galactose (5.4:4.4:1.2:1). In summary, this study identifies crude EPS-Ef1 as the heat-resistant postbiotic component. Crude EPS-Ef1 possesses the dual effects of suppressing intestinal inflammation and promoting intestinal epithelial cell proliferation, which provides a theoretical foundation for a crude EPS-Ef1-based postbiotic. Full article

The cause of the Cambrian explosion is one of the centuries-old puzzles. For centuries, scholars from numerous disciplines have proposed various theories based on evidence such as paleontological fossils and changes in geology and climate to try to reveal the cause of the Cambrian explosion, but no satisfactory conclusion has been reached. We explored a possible cause of the Cambrian explosion based on the evolution mechanism of genome sequences of existing species. Previous studies have found that the CG- and TA-independent selection intensities and the mutual inhibition relationship between them determine the evolution state of genome sequences. Based on the evolution mechanism of genome sequences, we analyzed the distribution of CG- and TA-independent selection intensities in animals and plants. We believed that the phase transition process from the evolution mode dominated by TA-independent selection to that dominated by CG-independent selection is an important cause of the Cambrian explosion. Consequently, we deduced the evolution time corresponding to the evolution state of genome sequences and gave the origin time of species branches. The results are largely consistent with existing paleontological evidence for animal branches and some plant branches, which verifies the rationality of our conjecture, though differences for certain plant groups require further investigation. Our study provides a novel way to reveal the cause of the Cambrian explosion and the origin time of species branches through existing genome sequences. Full article

Non-human primates are frequently used in anatomical and physiological research due to their similarity to humans. Currently, echocardiographic reference values are missing. Therefore, this study evaluated echocardiographic parameters in Callithrix spp., focusing on marmoset species under human care. Using color Doppler, M-mode, and B-mode, in a MyLab Gamma device (Esaote, Italy), examinations were conducted on 168 clinical healthy animals of the species Callithrix penicillata, C. aurita, C. jacchus, and hybrids, of both sexes, with an average weight of 328 ± 71 g. The samples were collected from the Mucky Project and the São Bernardo do Campo Zoo in São Paulo, Brazil, between November 2021 and May 2022. The animals were restrained with isoflurane, using a mask for induction and maintenance at a rate of 1 to 3% with 100% oxygen. Parameters such as the ventricular and atrial diameter, shortening fraction, and ejection fraction, among others, were measured. Cardiac reference values were assessed. The mild insufficiencies of the mitral and tricuspid valves were the most common findings in cases with alterations. These data serve as a refence for monitoring cardiac health in marmosets, aiding in both conservation and the management of captive primates. Full article

Human milk (HM) is a complex biological fluid that plays a significant role in infant health, influenced by maternal dietary habits and body composition. This study aimed to explore how maternal diet and nutritional status affect the microbial composition of HM. In this pilot study, 15 mothers were recruited from a maternity ward and assessed for dietary habits through a semi-structured food frequency questionnaire and a 3-day dietary record. Maternal body composition was evaluated using bioelectrical impedance analysis. HM samples were collected for microbiota analysis, focusing on the diversity and composition of bacterial communities via 16S rRNA sequencing. The study identified that maternal nutrient intake significantly correlated with the composition of HM microbiota. Specifically, Firmicutes abundance showed positive correlations with animal protein (τ = 0.39; p = 0.043), total carbohydrates (τ = 0.39; p = 0.043), and vitamin A (τ = 0.429; p = 0.026). Bacteroidota was positively correlated with retinol (τ = 0.39; p = 0.043). Higher consumption of dietary fiber (>24 g/day) did not yield significant differences in bacterial composition compared to lower intake (<24 g/day) (p = 0.8977). Additionally, no significant differences were found in overall bacterial abundance across different maternal characteristics such as age, mode of delivery, or breastfeeding type. This study underscores the importance of maternal diet in shaping the HM microbiota, which may have implications for infant health. Dietary modifications during lactation could be a strategic approach to promote beneficial microbial colonization in HM. Further research is warranted to confirm these findings and explore the underlying mechanisms. Full article

Introduction: Intradural extramedullary and intramedullary spinal tumors are rare, complex to treat, and require advanced surgical techniques. Ultrasonic aspirators, commonly used for tumor removal, can cause sensory and motor deficits, including loss of motor evoked potentials (MEPs). This study aims to evaluate the safety and efficacy of ultrasonic aspirators in intramedullary tumor surgery using a swine model, comparing different systems and techniques. Methods: Ten pigs underwent D1-D3 laminectomy and myelotomy, with adipose tissue simulating a tumor. The ultrasonic aspirators were tested under varying conditions (fragmentation power, suction, application time, and vibration mode). The primary endpoint is to evaluate the impact of the chosen variables on motor function damage. The secondary endpoints are histological evaluation of the type of damage caused by ultrasound aspirators and the effect of steroid drugs on MEPs’ impairment recovery. Results: Ultrasound aspirators can cause a significant MEP signal reduction when used in continuous mode, with fragmentation power >30 for more than 2 min (p < 0.001). Suction does not affect MEPs. When used in alternating/pulsatile mode, fragmentation power and application time do not affect MEPs. The two-way ANOVA analysis on the interaction between fragmentation power and application time in continuous mode did not demonstrate a significant interaction (p = 0.155). Time alone does not affect motor damage (p = 0.873). Betamethasone can restore MEPs’ signal after damage if administered immediately. Conclusions: Using ultrasonic aspirators in an animal model of intramedullary tumor surgery is safe. The main factor that resulted in the responsibility of motor function impairment is the fragmentation power. Full article

Studies of positional (=locomotor and postural) behavior are central to understanding how animals interact with the challenges imposed by their environment and are crucial for conservation management. The present study investigates, for the first time, the positional behavior and substrate use of the endangered southern pygmy slow loris Xanthonycticebus pygmaeus. Despite their very specialized morphology and ecology, the positional behavior of lorises is understudied. Behavioral data were collected using 30-s scan instant sampling on seven captive animals housed in a large, enriched enclosure of the Poznań Nowe Zoo (Poland) during February–June 2013. Pygmy slow lorises were almost exclusively arboreal and most activities occurred on multiple substrates (82.93%). Small (57.91%) and large (28.28%) substrates were extensively used. Horizontal (42.11%) and oblique (38.47%) substrates dominated. Clamber (39.39%), quadrupedalism (33.77%), and vertical climb (17.62%) were the main locomotor modes. Standing was the dominant posture (47.23%), followed by hanging (27.32%) and clinging (11.31%). Our results concur with the limited observations available on other lorisines; pygmy slow lorises employed a diverse and flexible positional repertoire as an adaptation to the exploitation of the continuous forest layers with intertwined small substrates of various inclinations. Consequently, protecting and managing these habitats, supported by ex situ reintroduction programs, can effectively contribute to the conservation of the species’ populations. Full article

Cyanobacteria can produce a wide range of toxins which have acute and chronic adverse health effects. Affecting a variety of mammalian systems, they are generally characterized according to their mode of action and the organs affected. Cyanobacterial neurotoxins are one cyanotoxin class that can negatively affect human health, and representatives of other cyanotoxins classes are increasingly showing neurotoxic effects. Of the various human exposure routes to cyanobacterial toxins, the significance of the airborne and inhalation route requires much greater clarity and understanding. People may be exposed to mixtures of cyanobacterial neurotoxins through the inhalation of sprays and dust, along with the potential to directly enter the central nervous system when crossing the blood-brain barrier. This review aims to summarize the current state of knowledge concerning airborne cyanobacterial neurotoxins, research gaps, health effects, and the need for management practices to protect human and animal health. Full article

The World Health Organization notes that some bacteria have been demonstrated to possess significant public health risks; they have antibiotic resistance, and there are fewer alternatives for control. The n-hexane extract and cinaguaiacin obtained from Artemisia cina show promising antibacterial activity, including against multidrug-resistant bacteria that affect animal and human health. Objective: The aim of this study was to determine the antibacterial activity of the n-hexane extract of A. cina and cinaguaiacin against multidrug-resistant bacteria. Methods:A. cina was collected in the pre-flowering period, the n-hexane extract was obtained, and chromatographic techniques and structure were used to separate the lignans, which were elucidated with nuclear magnetic resonance techniques. Four ATCC strains were used, and four strains were isolated from clinical cases with different resistance profiles. The antibacterial activity was determined by calculating the Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC), the time-kill kinetics assay, and the cell membrane integrity and DNA release assay. Molecular docking studies of lignans demonstrated the binding mode involved in the active site of DNA gyrase B. Results: The n-hexane extract inhibited growth against 87.5% of the strains tested (MIC 5.31 to 42.5 mg/mL) and showed bactericidal activity against 25% of the strains tested (MBC 0.62 to 85 mg/mL). Cinaguaiacin inhibited growth against 100% of the strains tested (MIC, 0.56 to 2.25 mg/mL) and exhibited bactericidal activity against 25% of the strains tested (MBC, 0.62 to 85 mg/mL). Conclusions: The mechanism of cinaguaiacin’s action may be associated with damage to the plasma membrane, as the protein and DNA levels were higher than those of the positive control. The n-hexane extract and cinaguaiacin obtained from A. cina showed a bacteriostatic or bactericidal effect, depending on the strain evaluated. Full article

This article argues that environmental education must move beyond knowledge transmission to become a transformative, psychological, and relational practice. Rooted in the One Health framework, which emphasizes the interconnectedness of human, animal, and ecological well-being, this article positions curiosity as a central catalyst for ecological and psychological integration. While this article specifically engages with the One Health framework, the same integrative principles apply equally to the closely related Planetary Health perspective, emphasizing interconnected human, ecological, and planetary well-being. Drawing from Jungian and post-Jungian psychology, ecopsychology, and educational theory, it redefines curiosity as a symbolic, ethical, and affective mode of engagement with the Other, both within the psyche and in the more-than-human world. Through boredom, dialogue, narrative, and embodied practices, curiosity creates space for inner movement, narrative reconfiguration, and a relational mode of knowing that can confront ecological crises with imagination, patience, and integrity. This article offers pedagogical strategies to cultivate this deeper form of curiosity as a foundation for lifelong ecological engagement. Full article