Elina Beatriz Reinoso

El uso de inteligencia artificial generativa en educación superior abre nuevas posibilidades para abordar problemas. En este trabajo se describe una experiencia didáctica realizada en la asignatura Genética Microbiana de la carrera de Microbiología, donde se aplicó una actividad de aprendizaje basado en problemas para analizar un caso de Escherichia coli resistente a ciprofloxacina y β-lactámicos en ámbitos productivos y clínicos. Los estudiantes, organizados en grupos, utilizaron distintas herramientas de IA para generar hipótesis, identificar genes y mutaciones asociadas a resistencia, como también diseñar estrategias experimentales basadas en PCR y qPCR. Los resultados evidenciaron avances en la integración conceptual, la formulación de hipótesis y el diseño experimental, junto con un uso crítico de la IA. Los estudiantes identificaron el valor de estas herramientas para agilizar tanto el razonamiento inicial como sus limitaciones, especialmente la necesidad de verificación conceptual y contraste con bibliografía científica. La actividad promovió además procesos metacognitivos, discusión grupal y toma de decisiones. La incorporación guiada de IA generativa favoreció aprendizajes significativos y desarrolló habilidades esenciales para la práctica científica, constituyendo un recurso pedagógico complementario que potencia, pero no reemplaza, la revisión crítica, el método científico y la función docente.

Enterococcus lactis is increasingly recognized as an emerging mastitis pathogen, yet the functional basis of its virulence and associated health risks remain poorly defined. This study presents an integrated genomic and phenotypic characterization of E. lactis strain EL-A150 isolated from bovine subclinical mastitis. Whole-genome sequencing revealed a 2.49 Mb circular chromosome encoding multiple genes associated with adhesion (acm, bepA, fms, sagA), biofilm formation (empB, empC) and antimicrobial resistance, including determinants related to aminoglycosides and macrolides. Phenotypic assays demonstrated rapid growth, strong biofilm-forming capacity and high adhesion to bovine mammary epithelial cells, while internalization remained low and intracellular persistence was transient. Comparative genomic analyses confirmed the taxonomic placement of the strain within the E. lactis clade (ANI up to 99.5% against reference genomes) and revealed a limited resistome composed of chromosomally encoded genes, with no detectable plasmids or major mobile genetic elements. Collectively, these findings demonstrate that E. lactis EL-A150 possesses a coordinated set of traits conducive to intramammary colonization, supporting its classification as an opportunistic pathogen. The convergence of virulence potential and clinically relevant antimicrobial resistance within a single isolate underscores a One Health concern and highlights the need for surveillance frameworks that integrate functional validation with genomic risk assessment.

Streptococcus uberis is a bovine mastitis pathogen with a demonstrated ability to form biofilms. However, the dynamics of this process remain poorly characterized. This study aimed to comprehensively characterize biofilm formation in four S. uberis strains that differed in their biofilm-forming capacity, from weak to strong producers, and in the presence of key virulence-associated genes, such as sua, hasA and hasC. To achieve this, we integrated structural, biochemical, physiological and transcriptional analyses using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), spectral flow cytometry and qRT-PCR. The multi-faceted analysis revealed a coordinated maturation peak at 48 h, characterized by a structured architecture with water channels, a distinct biochemical signature rich in polysaccharides and proteins, and a predominantly viable bacterial population. This peak coincided with a marked upregulation of key virulence-associated genes, with sua expression increasing 2.5-fold and hasA increasing 3-fold at 48 h. This mature biofilm conferred high tolerance to antibiotics, with eradication concentrations (>256 µg/mL) exceeding planktonic MICs, although tetracycline was notably effective. At 72 h, the biofilm entered a dispersion phase characterized by structural collapse and reduced viability. These findings establish S. uberis biofilm maturation as a highly coordinated process, providing new insights into the biofilm lifecycle of this important pathogen and identifying key temporal and molecular targets for future interventions.

Bovine mastitis is the most common infectious disease in dairy herds and causes important economic losses. Various pathogens can cause the disease, with Staphylococcus aureus being one of the most significant. S. aureus can cause clinical, subclinical, and chronic forms of the disease due to a variety of virulence factors, including protein A, coagulase, toxins, and adhesins. The presence of methicillin-resistant S. aureus strains complicates treatment protocols and raises concerns about antimicrobial resistance. The genetic characterization of these strains, utilizing techniques such as molecular typing by pulsed-field gel electrophoresis (PFGE), reveals the existence of different genetic and virulence profiles, as well as the geographical variations in the distribution of these genotypes. The role of next-generation sequencing (NGS) technologies, functional genomics, and multi-omics approaches in the genetic research of bovine mastitis are highlighted, providing a complete understanding of its genetic basis and opening opportunities for targeted interventions and improved disease control strategies in the dairy industry. This review highlights the importance of understanding the genetic diversity and pathogenic mechanisms of S. aureus in bovine mastitis to develop effective disease management strategies and reduce economic losses in the dairy sector globally.

Dengue is an emerging disease of high impact on human health. Plants are an important source of new antivirals and Arachis hypogaea stands for its biological properties. The aim of this study was to evaluate the cytotoxicity and antiviral activity and elucidate the antiviral mechanism of ethanolic extracts from A. hypogaea against dengue virus 2 (DENV-2). The skin or tegument ethanolic extract (TEEs) and seed ethanolic extract (SEEs) were obtained. Cytotoxicity was evaluated by MTT and Neutral Red Uptake (NRU). Antiviral activity was evaluated at different stages of the viral replication cycle by the lysis plaque reduction method. The 50% inhibitory concentration (IC₅₀) and selectivity index (SI) were determined. Antiviral activity was further determined by RT-qPCR. The CC₅₀ values were 169 (NRU) and 65 (MTT) µg/mL for TEE. In addition, the CC₅₀ values were >1400 (NRU) and 636 (MTT) µg/mL for SEE. The TEE demonstrated 99.9 ± 0.1% viral inhibition. The TEE presented an IC₅₀ = 3.47 and SI of 48.7 (NRU) and 18.73 (MTT). Its mechanism of antiviral action is broad and it acts in the viral adsorption–penetration stage and inhibits the first steps of infection in the post-penetration stage. It is also capable of acting as virucidal and as prophylactic. Studies of RT-qPCR indicated that the TEE inhibited viral RNA synthesis. These findings suggest that the TEE from A. hypogaea could be a promising antiviral candidate for treating DENV-2 infections.

The use of antimicrobials in the dairy production environment for mastitis control must take etiology, clinical signs, economic impacts, and regulatory frameworks into consideration. The objective of the present review is to highlight important aspects of the dynamics of antimicrobial use in dairy production and the potential impacts on the main pathogens circulating in this environment, considering the parameters set by the World Health Organization (WHO) regarding the priority of monitoring as well as control strategies for these agents, such as the methicillin-resistant Staphylococcus and the beta-lactamase-producing Escherichia coli. Understanding the animal-environment-pathogen triad is crucial for establishing control measures and preventing the spread of bacterial resistance. Implementing mastitis prevention and control measures in dairy farms, considering process flow and personnel qualification, enables a reduction in antimicrobial usage and contributes to prevent the spread of resistant bacterial agents in the dairy production environment, minimizing the relapses and the chronicity of the infectious process. A utilização de antimicrobianos no controle de mastite em ambiente de produção leiteira deve considerer alguns aspectos como a etiologia, os sinais clínicos, os impactos económicos e a legislação. O objetivo da presente revisão é destacar aspectos importantes na dinâmica do uso de antimicrobianos na produção leiteira e os potenciais impactos sobre os principais patógenos circulantes neste ambiente, considerando os parâmetros estabelecidos pela Organização Mundial da Saúde (OMS) quanto à prioridade de monitoramento, bem como estratégias de controle para esses agentes, como o Staphylococcus resistente à meticilina e a Escherichia coli produtora de beta-lactamase. Compreender a tríade animal-ambiente-patógeno é crucial para estabelecer medidas de controle e prevenir a propagação da resistência bacteriana. A implementação de medidas de prevenção e controle de mastites nas propriedades leiteiras, considerando o fluxo do processo e a qualificação do pessoal, permite a redução do uso de antimicrobianos e contribui para prevenir a propagação de agentes bacterianos resistentes no ambiente de produção leiteira, minimizando as recidivas e a cronicidade do processo infeccioso.

Dada su inmensa extensión geográfica, Argentina resguarda una sorprendente variedad de especies vegetales, y la provincia de Córdoba se destaca como una de las principales proveedoras de especies aromáticas y medicinales autóctonas al mercado nacional. Estas plantas, en su mayoría, provienen de los Departamentos del Oeste de la provincia, una región que alberga una gran diversidad de estas especies. En los últimos años, los colegios de nivel medio de esta región han estado trabajando arduamente en el aprendizaje y la preservación de la flora local. Estos esfuerzos incluyen el estudio de las diferentes variedades de plantas, sus métodos de cultivo, propiedades y usos populares. Simultáneamente, docentes e investigadores de la Universidad Nacional de Río Cuarto han llevado a cabo investigaciones exhaustivas sobre plantas medicinales, evaluando diversas propiedades biológicas, como su capacidad antimicrobiana, citotóxica, antiinflamatoria, entre otras. Como parte de un proyecto de divulgación científica, se llevaron a cabo una serie de actividades en colegios de nivel medio de la región de Córdoba con el propósito de transmitir las vastas experiencias acumuladas a lo largo de años de investigación por parte de docentes e investigadores a estudiantes y a la comunidad en general. Estas actividades comprendieron tanto aspectos teóricos como prácticos, y culminaron en la creación de un documento de divulgación científica titulado "Una Farmacia en el Monte". En este libro se profundiza en la relevancia de las plantas autóctonas y su potencial farmacológico, además de promover la conservación de estas especies para que los estudiantes de la región se conviertan en agentes multiplicadores de este conocimiento. Tanto los estudiantes de nivel medio como la sociedad en general se beneficiaron al ser receptores de los estudios científicos realizados hasta el momento, lo que aumentó la conciencia sobre la importancia de la vegetación autóctona en los ecosistemas y su preservación, con el fin de mantener el equilibrio ecológico y aprovechar al máximo sus propiedades medicinales.

Aim Nine Streptococcus uberis strains with different biofilm-forming profiles in relation to their capacity of adherence and invasion to MAC-T cell lines were examined. Additionally, virulence genes were also linked to adherence and invasion. Methods and Results All S. uberis were able to adhere and invade the cells at different levels. UB56 strain showed the highest percentage of internalization (3.65%) and presented a moderate level of adhesion (4.6 × 10⁶). In contrast, UB152, the most adherent strain (8.7 × 10⁶) showed a low capacity to internalize (0.65%). Eight strains were able to persist intracellularly over 96 h regardless of their adherence or invasion level. Statistical analysis between biofilm-forming ability and the adhesion capacity showed no significant differences. Presence of virulence genes involved in the adhesion process (gapC, hasABC, lbp, pauA and sua) showed that the strains harboured different genes and seven patterns could be observed. Conclusion Statistical analysis showed no correlation between the virulence gene patterns and the adhesion capacity or the percentage of internalization. Biofilm-forming ability did not influence the invasion capacity. Likewise, adherence and invasion capacity may be strain dependent. Significance and Impact of the Study Findings from this study provide new insights on biofilm and invasion capacity of S. uberis strains. Results could help to design adequate control strategies.