Iang Schroniltgen Rondón-Barragán

Objetivo. Determinar serorreactividad mediante ELISA indirecto y positividad mediante PCR del EHV-1 en equinos reproductores en el departamento del Meta. Materiales y métodos. Bajo un estudio transversal se obtuvieron muestras de sangre de 41 caballos reproductores de cinco municipios del departamento del Meta. Se realizó una prueba de ELISA indirecta que utiliza un anticuerpo monoclonal contra IgG de equino y un PCR semianidado para la amplificación de un fragmento del gen gH para la glicoproteína H de 287 pb del EHV-1. Resultados. La PCR detectó un menor número de animales positivos 9 (9/41) que el ELISA (11/41). Conclusiones. Se confirma la circulación natural del virus en los municipios estudiados, lo que obliga a implementar medidas de prevención y control. El uso complementario de técnicas diagnósticas sería de valiosa ayuda en el diagnóstico oportuno de la infección.

The genus Auricularia holds significant ecological importance due to its role in wood decaying and notable economic value as both an edible and medicinal resource. This study investigates the diversity of Auricularia species in Colombian Andes using an integrative approach. Species identification was based on macromorphological and micromorphological characteristics, alongside molecular analyses employing ITS and LSU markers. A total of 184 sequences of 81 specimens and 30 species were used to construct a phylogenetic tree including RPB2 marker sequences taken from GenBank. The results revealed six Auricularia species in the Colombian Andes: A. subglabra, A. cornea, A. fuscosuccinea, A. nigricans, A. brasiliana, and the newly described A. ibaguensis. This study provides morphological descriptions, distribution records, and interspecific distinctions, aligning these taxa with four out of the five recognized Auricularia species complexes. Novel sequences deposited in GenBank enhance taxonomic resolution, particularly within the A. cornea complex. These findings contribute new insights into the taxonomy of Auricularia in the Colombian Andes and emphasize the need for further research on Neotropical species, which may show significant differences from taxa in other biogeographic regions.

Global consumers have ongoing concerns about the effects of animal production systems on animal welfare and their effects on quality attributes of food products from intensive production systems

Background: Neuroinflammation can be triggered by several causes, including traumatic brain injury (TBI) and exposure to toxicants such as chlorpyrifos (CPF), leading to chronic disabilities and substantial healthcare costs. Proteins such as CD59 and GMFB are implicated in various brain regulatory mechanisms. Investigating their roles can provide valuable insights into their role in pathologies such as TBI. Aim: This study aimed to analyze the molecular characteristics of the CD59 and gmfb genes and assess their relative gene expression in brain tissues of Piaractus orinoquensis subjected to brain injury using quantitative PCR (qPCR). Methods: Thirty Piaractus orinoquensis were allocated to brain injury or CFP exposure models. Brain injury was induced by telencephalic stab puncture, and CPF exposure was performed at a sublethal concentration of 0.011 µg/L. Brain regions, including the olfactory bulb, telencephalon, and optic chiasm, were collected at designated time points, and qPCR analysis was performed. CD59 and gmfb genes were sequenced and characterized using bioinformatic tools. Results: Both genes exhibited conserved features compared to other fish species. In the brain injury model, fish subjected to brain injury showed reduced expression of CD59 and gmfb compared to controls, suggesting a loss of immunomodulation associated with brain damage. Conversely, in the CPF-treated group, increased expression of CD59 in the olfactory bulb and gmfb in the optic chiasm was observed. Conclusion: CD59 downregulation after brain injury suggests a loss of immunomodulatory capacity following brain damage. In CPF-exposed fish, the overexpression of both CD59 and gmfb in some of the brain tissues demonstrated the capacity of the toxicant to generate region-specific immunoactivity and neurotoxicity in the brain.

Pleurotus tolimensis is described as a novel species discovered in an urban remnant of Tropical Dry Forest in Tolima, Colombia. Species delimitation was supported by a combination of macro- and micromorphological characters, as well as multilocus phylogenetic analysis. Phylogenetic analyses based on a combined dataset comprising the internal transcribed spacer (ITS), the large subunit of the nuclear ribosomal RNA gene (28S), the translation elongation factor 1-α gene (TEF) and the largest and second largest subunits for the RNA polymerase genes (RPB1, RPB2). Phylogenetic analyses were inferred in a maximum likelihood and Bayesian inference framework. The results allowing the placement of P. tolimensis as a distinct lineage within the genus Pleurotus, closely related to P. floridanus. Diagnostic features include a light orange pileus with grayish edges, mucronate pleurocystidia, larger basidiospores, and the presence of rhomboid crystals near the hymenium, also present in culture. This study not only clarifies the taxonomy of Colombian Pleurotus but also highlights the high but still underexplored fungal diversity of the critically endangered Tropical Dry Forest. By contributing to reducing the Linnaean biodiversity shortfall, these findings provide essential baselines for future ecological, conservation, and applied research on Neotropical funga.

Intensive farming methods have improved productivity, but public concerns have arisen regarding the welfare of production animals, particularly laying hens, and consumers demand higher animal welfare standards in all animal production systems. This study evaluated the impact of conventional cage (CC) versus cage-free (CF) housing systems on the gene expression of some peptide hormones regulating food intake along the gut–brain axis in laying hens at 80 wks. Sixty thousand Hy-Line Brown hens were reared under commercial farm conditions until week 15. At 16 wks, hens were randomly assigned into two housing systems: CC (450 cm²/bird) and CF (1111 cm²/bird). At week 80, hypothalamic, proventricular, duodenal, jejunal, and ileal tissues were sampled from six hens per system for qPCR analysis. Relative mRNA transcript levels of peptide hormones involved in the regulation of food intake (GHRL, Ghsr, NPY, AGRP, POMC, CCK, CART, CRH, MC4R, MC1R, MC5R) were quantified by qPCR using the most stable reference genes. CC hens exhibited upregulation of duodenal anorexigenic genes (POMC, CCK, CART, CRH) and stress-related MC4R, while CF hens showed higher ileal expression of foraging-related AGRP. No differences were observed in orexigenic peptides (GHRL/Ghsr, NPY). These findings suggest that housing systems differentially modulate gut–brain axis signaling. Specifically, CC environments appear to upregulate satiety signals, whereas CF systems seem to enhance the expression of genes linked to foraging behavior.

Small ruminant production is increasingly affected by heat stress, with recent heat waves highlighting growing economic and welfare-related challenges. Chronic exposure to elevated temperatures disrupts thermoregulation, reduces feed intake, slows growth, compromises meat quality, and increases mortality. This study evaluated the effects of chromium-yeast supplementation at different doses and timepoints on physiological and molecular stress biomarkers in heat-stressed lambs. Forty-eight clinically healthy 6-month-old Katahdin lambs (average weight 20 ± 2.9 kg) were assigned to a 2 × 4 factorial design, with two ambient temperature conditions (heat stress [HS] and thermoneutral [TN]) and four levels of dietary Cr-yeast (0, 0.2, 0.4, and 0.8 mg/kg of dry matter intake). Lambs were housed individually in pens (1.2 × 2.5 m), with ad libitum access to water, and fed a 50:50 corn silage and concentrate diet (excluding mineral premix) twice daily. Blood samples were collected at days 0, 30, and 60 to evaluate plasma cortisol and the expression of hsp60 and hsp70. Chromium bioavailability was assessed by blood levels using absorption chromatography, and glucose clearance was measured at the end of the experiment. Significant reductions in cortisol and hsp70 expression were observed after 30 days of Cr-yeast supplementation under HS conditions (p < 0.05), particularly at the highest dose. For hsp60, a significant reduction was observed at the highest dose on day 30 under HS (p < 0.05). These effects were not sustained on day 60 (p > 0.05). No significant differences were detected under TN conditions (p > 0.05). These findings suggest that Cr-yeast may offer short-term physiological and cellular protection against chronic heat stress in lambs.

Different conditions of production systems including stocking density, thermal conditions, and behavior restriction can have a significant detrimental effect on the health and performance of laying hens. The conventional cage system is one of the systems that have been reported to cause stress problems in birds, due to social and behavioral stress. Emerging technologies have facilitated a deeper understanding of animal responses to various scenarios and can be an additional tool to conventional ones to assess animal welfare, where transcriptomic analysis has the potential to show the genetic changes that occur in response to stress. According to this, the aim of this work was to characterize the liver transcriptome of hens housed under two egg production systems (conventional cage and cage-free). Liver tissue from Hy-Line Brown hens housed in conventional cage (n = 3) and cage-free (n = 3) production systems at week 80 of age was processed using the Illumina platform to identify differentially expressed genes with a padj < 0.05. Regarding the differentially expressed genes, 138 genes were found, of which 81 were upregulated and 57 downregulated. Some of the genes of interest were TENM2, GRIN2C, and ACACB, which would indicate greater fat synthesis in the liver of caged hens. The enriched KEGG pathways were DNA replication and the cell cycle. In conclusion, it was identified that the cage production system may influence DNA replication and the cell cycle since the genes related to these terms were found suppressed, which would indicate cellular instability.

EHV‐1 is one of the most prevalent viral pathogens in horses; however, its prevalence is not well defined by cross‐reactions of serological tests. Thus, this study aims to determine EHV‐1/‐4 prevalence in Colombian creole horses from Ibagué, Tolima, using molecular techniques, as well as to determine possible risk factors associated with viral infection. A cross‐sectional study was carried out in 110 equines blood, serum, and semen samples from Ibagué, Tolima. Antibodies against EHV‐1/‐4 were determined through indirect ELISA. EHV‐1 was detected by amplifying the glycoprotein H gene through heminested PCR, and risk factors were calculated with chi‐square, odds ratio, and fisher test. EHV‐1/‐4 antibodies were found in 11.8% of the horses. Moreover, the presence of EHV‐1 and EHV‐4 was determined in blood, serum, and semen of healthy clinical equines, with a prevalence infection in horses of 43.36% for EHV‐1 and 2.7% for EHV‐4. Sex, age, births number, abortions, natural breeding, and artificial insemination did not show significance as risk factors. This study determined a high prevalence of EHV‐1 and low prevalence of EHV‐4 in horses from Ibagué, Tolima. Furthermore, the possibility of finding the infectious agent in blood, serum, and semen was demonstrated. We recommend the use of blood and serum samples for virus detection and the development of new studies to assess EHV‐1 infection feasibility in venereal transmissions.

Feline hemoplasmosis is a disease with worldwide distribution, mainly in tropical countries, where its transmission is favored by the presence of vectors such as fleas and ticks. In Colombia, the diagnosis of the disease in small animals has been limited to the identification of the pathogen in blood smears, which have low sensitivity and specificity, demanding methods of higher diagnostic value, such as those based on molecular techniques. The objective of the present study was to investigate the prevalence of Mycoplasma spp. in felines from the city of Ibagué using the PCR and the associated risk factors. Briefly, blood samples were taken from cats (n=150), DNA was extracted, and Mycoplasma spp. DNA was detected by PCR. Additionally, a survey was carried out on the owners to determine possible risk factors associated with the presence of the pathogen. The study revealed a prevalence of 16.6% of cats positive for Mycoplasma spp. The results showed a higher incidence in cats older than one year compared to males and a greater predisposition when the cats were positive for FIV and FeLV. It is noteworthy that most of the cats have outdoor access, do not have a vaccination for FeLV, or have not carried out diagnostic tests for viral diseases, which may underestimate the health status of the cats. This first epidemiological report in the city of Ibague highlights the demand for molecular diagnosis for hemotropic pathogens and includes hemoplasma in the differential diagnosis scheme for cats.