Edwaldo Villanueva Pedraza

Antimicrobial resistance is a growing threat to public health and the environment, especially in vulnerable ecosystems such as the Amazon. The confluence of the Marañón, Utcubamba, and Chinchipe rivers, known as the Pongo de Rentema, is a strategic area where water pollution could facilitate the spread of antibiotic resistance genes. This study aims to assess water quality in this region under the “One Health” approach by analyzing physicochemical parameters, heavy metals, and the presence of antimicrobial resistance genes. Water samples were collected from five sampling points during September and October 2024. Physicochemical parameters were analyzed in situ, and heavy metal concentrations were determined using atomic emission spectrophotometry. The presence of Escherichia coli and Pseudomonas aeruginosa was evaluated through selective culture, and the detection of resistance genes (marA, ermC, amp, QEP, and qEmarA) was performed using conventional PCR. Physicochemical parameters were within the limits established by Peruvian regulations, except for total dissolved solids in the Utcubamba River. Elevated levels of lead and chromium were detected at some points. Additionally, resistance genes were identified in E. coli and P. aeruginosa, providing evidence of antimicrobial resistance dissemination in the water. Water pollution in the Pongo de Rentema poses an environmental and public health risk due to the presence of heavy metals and antimicrobial resistance genes. Continuous monitoring and environmental management strategies under the “One Health” approach are recommended to mitigate these risks.

The global poultry industry is challenged to meet rising demands for sustainable production, prompting interest in plant-based feed additives like Urtica dioica due to their nutritional and functional properties. The objective of this study was to evaluate the effects of dietary inclusion of Urtica dioica on growth performance, serum biochemical indicators, and intestinal microbiota composition in broiler chickens. The 42-day feeding trial involved 120 male Cobb 500 broiler chickens with an average initial body weight of 41.7 ± 1.2 g. Broiler chickens were randomly allocated to four experimental groups, each consisting of six replicates with ten chickens. The treatment groups received basal diets supplemented with 1% (T1), 2% (T2), or 3% (T3) Urtica dioica, while the control group (T0) was fed the basal diet without additives. Productive performance parameters were recorded weekly, and on day 42, blood profiles and intestinal microbiota composition were evaluated. Results showed that 1% Urtica dioica significantly improved live weight and feed conversion ratio (FCR) compared to the control group, with no additional benefits observed at higher inclusion levels. The biochemical assessment showed that broiler chickens supplemented with 1% Urtica dioica exhibited significant reductions in total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), and triacylglycerol levels compared to the control group. Microbial analysis demonstrated a significant increase in Lactobacillus spp. populations and a decrease in coliform bacteria in the 1% supplementation group, suggesting improved gut health. These findings indicated that 1% Urtica dioica supplementation enhances growth, lipid metabolism, and intestinal health in broiler chickens.

This study investigated the presence of antibiotic-resistance genes in drinking water consumed by the university community in the Peruvian Amazon. Water samples were collected from three primary sources: inflow from the distribution network, a storage cistern, and an underground intake. Conventional PCR was employed to detect genes associated with resistance to erythromycin (ermC), ampicillin (amp), ciprofloxacin (QEP), multidrug resistance (marA), and specific multidrug resistance in E. coli (qEmarA). Physicochemical analysis revealed compliance with most regulatory standards; however, groundwater samples showed lead concentrations exceeding legal limits (0.72 mg/L) and lacked residual chlorine. All sampling points tested positive for the evaluated resistance genes, demonstrating the widespread dissemination of resistance factors in drinking water. Contrary to initial expectations, resistance genes were also prevalent in treated sources. These findings reveal a critical public health risk for the university community, emphasising the need for effective disinfection systems and robust monitoring protocols to ensure water safety. The presence of these resistance genes in water is a critical public health concern as it can facilitate the spread of resistant bacteria, reducing the effectiveness of medical treatments and increasing the risk of infections that are difficult to control.

The magnetic field penetration depth poses challenges in communications, geophysical exploration, biomedical therapies, and superconducting device design. The objective of this systematic review was to identify, analyze, and understand the depth of magnetic field penetration in conductors, semiconductors, superconductors, insulators and natural materials, modelling applications in medicine, engineering, and basic sciences. An exhaustive search was carried out in databases such as Scopus, IEEE Xplore, ScienceDirect, and IOPSCIENCE using keywords such as depth and penetration and magnetic and field and materials. PRISMA was used as a method to define inclusion and exclusion criteria, ensuring quality, transparency, and methodological rigor, followed by a detailed statistical analysis. The results showed that the penetration depth varies according to the material, frequency, and application conditions. In human tissues, infrastructure, and agricultural applications, the penetration range is between 0.01 and 0.2 m, with the possibility of a range greater than one meter in specific applications. The higher the frequency, the lower the penetration depth is confirmed. In conclusion, the penetration of the magnetic field depends on material properties such as conductivity and magnetic permeability, frequency, and temperature. The developed models offer relevant information for future research and technological applications.

El objetivo del estudio fue investigar el efecto de la aplicación de diferentes abonos orgánicos sobre el desarrollo de la altura de la planta, diámetro de bulbo y dientes germinados del ajo (Allium sativum). Se utilizó un diseño completamente al azar (DCA) con un total de 4 tratamientos con 3 repeticiones. Los tratamientos fueron T0: Testigo absoluto sin sustrato, T1: Tierra agrícola proporción 1:1 con vermicompost con estiércol de ovino, T2: Tierra agrícola más Biol al 10% en dilución acuosa, T3: Tierra agrícola más 10% de ceniza de desechos orgánicos y sin adición actuó como control. Los datos se analizaron con el procedimiento GLM de SAS y las medias de los tratamientos se compararon con la prueba de Tukey. Los resultados mostraron que la adición del Biol al 10% en dilución acuosa y Vermicompost con estiércol de ovino al cultivo de ajo (Allium sativum), tuvieron el efecto más beneficioso en la germinación, diámetro y altura de la planta. Los valores más bajos para las características analizadas del cultivo de ajo (Allium sativum) se encontraron en el grupo control. Concluimos que el uso de Biol resultó en mayores rendimientos en la germinación de bulbos, altura de planta y diámetro de bulbo.

Los bloques multinutricionales (BMN) elaborados a partir de subproductos agroindustriales pueden brindar una alternativa asequible para reemplazar insumos tradicionales de maíz y torta de soya, con un balance energético, proteico en la alimentación animal. El objetivo de este estudio fue evaluar el efecto de BMN elaborados con subproductos agroindustriales sobre el comportamiento productivo de ganado lechero bajo un sistema extensivo. Se utilizaron 12 vacas de raza Girolando distribuidos en 4 grupos de 3 animales durante 30 días (10 días de adaptación y 20 días de evaluación). Se utilizó un diseño completamente al azar (DCA) para 4 tratamientos: El grupo control T0 consistió en el consumo de pasto Brachiaria (B. brizantha) y sales minerales. Los animales de los grupos T1, T2 y T3 fueron suplementados con bloques elaborados en niveles iguales con melaza, urea, sales minerales, sal común, cal, cemento, aceite de palma y diferenciados T2 y T3 con 30 % de torta de coco y 30 % de harina de palmiste, respectivamente. Se midió la producción lechera diaria (g/animal/día), la composición de la leche (proteína, grasa, lactosa, sólidos totales, %) y el consumo de la materia de los bloques (g/animal/día). El consumo total de materia seca (g/animal/día) en T1 821, T2 804 y T3 776 de los bloques, mejoró la producción láctea al determinarse diferencias significativas entre los grupos (p<0.01), evidenciándose un aumentó en un 30 % de la producción de leche. Los resultados obtenidos en este estudio con la suplementación de BMN tuvieron un efecto positivo en los parámetros de producción de leche, lo que podría atribuirse al mayor consumo de energía y nitrógeno cuando se usa como un suplemento alimenticio para vacas al pastoreo.

Multi-nutrient blocks (MNB) made from agro-industrial by-products can provide an affordable alternative to replace traditional corn and soybean meal inputs with an energy, protein balance in animal feed. The objective of this study was to evaluate the effect of BMN made from agro-industrial by-products on the productive performance of dairy cattle under an extensive system. Twelve Girolando cows were used, distributed in four groups of three animals for 30 days (10 days of adaptation and 20 days of evaluation). A completely randomised design (CRD) was used for 4 treatments: T0 control group consisted of consumption of Brachiaria grass (B. brizantha) and mineral salts. The animals in groups T1, T2 and T3 were supplemented with blocks made in equal levels with molasses, urea, mineral salts, common salt, lime, cement, palm oil and differentiated T2 and T3 with 30 % coconut cake and 30 % palm kernel meal, respectively. Daily milk production (g/animal/day), milk composition (protein, fat, lactose, total solids, %), and block matter intake (g/animal/day) were measured. The total dry matter intake (g/animal/day) in T1 821, T2 804 and T3 776 of the blocks, improved milk production by determining significant differences between the groups (p<0.01), evidencing a 30% increase in milk production. The results obtained in this study with BMN supplementation had a positive effect on milk production parameters, which could be attributed to the higher energy and nitrogen intake when used as a feed supplement for grazing cows.

El objetivo de este estudio fue evaluar la efectividad del medio agar Geisel preparado a diferentes concentraciones de Moringa oleifera en comparación con un medio comercial sobre el crecimiento y desarrollo de cepas de Escherichia Coli. Se evaluó el crecimiento microbiano a diferentes concentraciones de Moringa oleífera (Moringa), 0.1, 1 y 5% (p/v) en un medio de cultivo denominado Agar Geisel y como control un medio de cultivo en placa de agar comercial. Las bacterias se inocularon utilizando una técnica de estrias múltiples (con agotamiento) y luego se incubaron para evitar la condensación durante la incubación a 37 °C durante 24 a 48 h. Para evaluar el crecimiento de las cepas expresadas en unidades formadoras de colonias, consideramos las características culturales y microscópicas. Se concluye que el medio de cultivo alternativo preparado con una dilución al 1% de agar Geisel de Moringa contiene los nutrientes necesarios y suficientes para el crecimiento, desarrollo, supervivencia y viabilidad de la bacteria (Eschericha Coli ATCC No. 8739).