Aspectos fármaco-epidemiológicos de la enfermedad respiratoria bovina bacteriana en feedlots.: una problemática a resolver

La enfermedad respiratoria bovina (ERB) es un proceso infeccioso multifactorial, causado principalmente por virus, bacterias y parásitos. Generalmente afecta a los bovinos menores de dos años de edad en crianza a feedlot, siendo una de las principales causas de morbi-mortalidad en esta categoría. Su tratamiento farmacológico llega a representar un 8% del total de los costos de producción, con alto porcentaje de fracasos terapéuticos. Las tasas de mortalidad debida a ERB son de aproximadamente 50%, presentándose la mayor parte en los primeros 45 días de ingresados los animales al feedlot. Tales fallas terapéuticas se deben a la ausencia de un diagnóstico basado en la evidencia y a la falta de protocolos de terapéutica racional, lo cual impide la correcta identificación de las cepas actuantes, conduciendo al tratamiento empírico de los animales y al desarrollo de resistencia bacteriana. Debido a que Argentina adolece de una falta de información sobre cepas resistentes en animales bajo condiciones de cría en feedlot, consideramos necesario difundir estrategias para optimizar una terapia antimicrobiana basada en evidencia científica, con rotación química de principios activos en animales naturalmente afectados. Se estima que ello incidirá en la reversión del uso indiscriminado de antibióticos y en la aparición de cepas bacterianas resistentes.Bovine respiratory disease (BRD) is a multifactorial infectious disease mostly caused by viruses, bacterias and parasites. It usually affects cattle less than 2 years-old in feedlots and is one of the leading causes of morbility and mortality in this category. The pharmacological treatment of BRD involves the 8% of the total production costs, with high failure rates. Approximately 50% of total mortality takes place during the first 45 days within a feeding period. The lack of evidence-based diagnosis and no identification of bacterial strains together with the empirical pharmacological treatment, probably contributes to the development of bacterial resistance. Due to the lack of information on resistant strains in feedlot animals in Argentina, it was considered necessary to optimize antimicrobial therapy based on scientific evidence with chemical rotation of active pharmaceutical ingredients in naturally affected animals. It is expected that this will promote the reversion of the indiscriminate use of antibiotics and the appearance of resistant bacterial strains

Efficacy of the probiotic strain Enterococcus faecalis CECT7121 in diarrhoea prevention in newborn foals

The aim of this work was to assess the effectiveness of the probiotic strain Enterococcus faecalis CECT7121 for the prevention of neonatal diarrhea in one to three day-old foals. Fecal samples from twenty foals divided randomly in experimental and control groups were studied. The experimental group (n=10) received E. faecalis CECT7121 (1 x 1010 CFU/ml) orally in the first day of life and for a 6 days period. The control group (n=10) received distilled water for the same period. In 4/10 of the foals from the control group diarrhea was observed, conversely diarrhea cases were not observed in any of the foals belonging to the experimental group. The differences between groups were statistically significant (p<0.001). E. faecalis CECT7121 was isolated in faeces from the second day of treatment until six days after the end of the probiotic administration. Therefore, E. faecalis CECT 7121 may be considered as a biological tool for the prevention of neonatal diarrhea in foals. Any adverse effects, at least under the conditions of this assay, but more efficacy studies should be performed to evaluate this organism in the prevention or treatment of diseases in foals.El objetivo de este trabajo fue evaluar la eficacia del probiótico Enterococcus faecalis CECT7121 en la prevención de la diarrea neonatal en potrillos de uno a tres días de edad. Se estudiaron muestras de materia fecal de veinte potrillos divididas al azar en grupos experimental y control. Los animales del grupo experimental (n=10) recibieron E. faecalis CECT7121 (1 x 1010 UFC/ml) por vía oral en el primer día de vida y por un período de 6 días. El grupo control (n=10) recibió agua destilada por el mismo período. Se observó que el 40% de los potrillos del grupo control presentaron diarrea, mientras que no se observaron casos de diarrea en ninguno de los potrillos pertenecientes al grupo experimental. Las diferencias entre los grupos fueron estadísticamente significativas (p<0,001). E. faecalis CECT7121 se aisló en heces desde el segundo día de tratamiento hasta seis días después del final de la administración del probiótico. Por lo tanto este hallazgo indicaría que E. faecalis CECT7121 podría ser considerado como una herramienta biológica para la prevención de la diarrea neonatal en potrillos sin ningún efecto adverso, al menos bajo las condiciones del presente ensayo, aunque más estudios de eficacia se deberían realizar para evaluar este organismo en la prevención o el tratamiento de enfermedades de los potrillos en los haras

Prevalencia de agentes bacterianos involucrados en casos de neumonías en <i>feedlot</i>

La enfermedad respiratoria bovina (ERB) es causante de pérdidas económicas en animales de engorde a corral. Las principales bacterias involucradas en su patogenia son Histophilus somni, Mannheimia haemolytica y Pasteurella multocida, y en menor medida Mycoplasma bovis y Trueperella pyogenes. En nuestro país son escasos los datos sobre la prevalencia de aislamientos bacterianos en pulmones de bovinos muertos por ERB. El objetivo de este trabajo fue determinar la prevalencia de aislamientos bacterianos en bovinos muertos naturalmente por ERB en engordes a corral en la región del sudeste de la provincia de Buenos Aires (Argentina). Se realizó la necropsia de 70 animales provenientes de 6 establecimientos de engorde a corral con síntomas respiratorios que fueron refractarios a tratamientos con antibióticos y que presentaron lesiones compatibles con neumonías bacterianas.Trabajo publicado en Cagliada, Maria del Pilar Lilia y Galosi, Cecilia Mónica (comps.). I Congreso de Microbiología Veterinaria. Libro de resúmenes. La Plata: Facultad de Ciencias Veterinarias, 2021.Facultad de Ciencias Veterinaria

Clinical and microbiological features of bacteremia caused by Enterococcus faecalis

Introduction: Enterococcus faecalis is a frequent etiologic agent of invasive infections in hospitalized patients. The aim of this study was to analyze clinical and microbiological features of bacteremia caused by E. faecalis. Methodology: Between 2011 and 2013, significant bacteremia caused by E. faecalis in hospitalized patients was studied. Patient characteristics, comorbid conditions, and 14-day mortality were recorded. Virulence genes esp, gelE, and cylA; opsonophagocytosis resistance; resistance to bactericidal effect of normal serum; beta lactamase production; and susceptibility to ampicillin, vancomycin, teicoplanin, gentamicin, and streptomycin were investigated. Results: E. faecalis strains were recovered from 33 bacteremic patients. Polymicrobial bacteremia was diagnosed in 2 patients; 10 patients died. Virulence genes were found in strains from both deceased patients and survivors. Sources of bacteremia included urinary tract infections (36.4%), vascular catheters (15.1%), abscesses (9.1%), and unknown (48.5%). Underlying diseases included cancer (30.3%), diabetes (36.4%), cirrhosis (6.1%), renal (36.4%), and chronic obstructive pulmonary disease (2.0%). Co-morbidities included alcohol use (26.1%); glucocorticoid therapy (19.0%); prior antibiotic therapy (60.6%); and central venous (21.2%), arterial (12.1%), and urinary (63.6%) catheters. Also, 57.6% of patients came from the intensive care unit (ICU); 33.3% had mechanical ventilation. Significant mortality-associated conditions included polymicrobial bacteremia, oncological disease, APACHE II score ≥ 20, ICU stay, renal disease, central venous catheter, and mechanical ventilation. Conclusions: Outcome of patients was associated with their status and not with the presence of virulence genes in E. faecalis strains. A significant percentage of bacteremia had undetermined origin. An alternate origin may be the gastrointestinal tract, through translocation.Facultad de Ciencias Médica

Bactericidal Activity and Synergy Studies of Peptide AP-CECT7121 Against Multi-resistant Bacteria Isolated from Human and Animal Soft Tissue Infections

AP-CECT7121 is an antimicrobial peptide, produced by Enterococcus faecalis CECT7121, with bactericidal activity against Gram-positive bacteria. The aim of this study was to evaluate the bactericidal activity of AP-CECT7121, alone and with gentamicin, against multi-resistant bacteria isolated from human and animals with soft tissue infections. During the period 2014–2015, bacterial strains producing human and animal soft tissue infections were studied. Samples from patients attended at a general hospital and cattle from four dairies in the Province of Buenos Aires (Argentina) were included. Twenty-two methicillin-resistant Staphylococcus aureus (11, human blood samples; 11, cow milk) and five vancomycin-resistant Ent. faecium strains isolated from four mastitic dairy cows were tested. AP-CECT7121 (12 mg/L) potency was assessed by time-kill curves alone or with subinhibitory concentrations of gentamicin. All staphylococcal strains were susceptible to gentamicin; enterococci did not show high-level gentamicin resistance. Colony counts were carried out at 0, 2, 4, 8, and 24 h of incubation. APCECT7121 showed bactericidal activity against all the enterococcal strains. In addition, AP-CECT7121 had a bactericidal effect on most staphylococci (16/22). Early AP-CECT7121/ gentamicin synergy (4–8 h) for all staphylococci was detected. At 24 h, synergy (19/22) and indifference (3/22) were observed. Synergy with gentamicin was detected for staphylococci. AP-CECT7121 constitutes an attractive candidate for its use as a natural therapeutic tool for the treatment of infections produced by multi-resistant Staph. aureus and vancomycin-resistant Ent. faecium isolated from humans and animals.Facultad de Ciencias Médica

Comparative Plasma Exposure and Lung Distribution of Two Human Use Commercial Azithromycin Formulations Assessed in Murine Model: A Preclinical Study

Azithromycin (AZM) therapeutic failure and relapses of patients treated with generic formulations have been observed in clinical practice. The main goal of this research was to compare in a preclinical study the serum exposure and lung tissue concentration of two commercial formulations AZM-based in murine model. The current study involved 264 healthy Balb-C. Mice were divided into two groups ( = 44): animals of Group A (reference formulation -R-) were orally treated with AZM suspension at 10 mg/kg of b.w. Experimental animals of Group B (generic formulation -G-) received identical treatment than Group A with a generic formulation AZM-based. The study was repeated twice as Phase II and III. Serum and lung tissue samples were taken 24 h post treatment. Validated microbiological assay was used to determine the serum pharmacokinetic and lung distribution of AZM. After the pharmacokinetic analysis was observed, a similar serum exposure for both formulations of AZM assayed. In contrast, statistical differences ( &lt; 0.001) were obtained after comparing the concentrations of both formulations in lung tissue, being the values obtained for AUC and Cmax (AZM-R-) +1586 and 122%, respectively, than those obtained for AZM-G-in lung. These differences may indicate large differences on the distribution process of both formulations, which may explain the lack of efficacy/therapeutic failure observed on clinical practice

Bacteriological resolve of pyoderma associated with canine demodicosis without antibiotic/antiseptic therapy

Generalized canine demodicosis is a disease caused by Demodex spp. commonly associated with infection by Staphylococcus spp., normal inhabitants of dogs skin. Both microorganisms proliferate within the hair follicles causing folliculitis and furunculosis. In the past, systemic antibiotic therapy was supported for all dogs with secondary bacterial infection. Nowadays, as the incidence of skin infections with multi-resistant bacteria is increasing, a judicious use of systemic antibiotics is recommended.Trabajo publicado en Cagliada, Maria del Pilar Lilia y Galosi, Cecilia Mónica (comps.). I Congreso de Microbiología Veterinaria. Libro de resúmenes. La Plata: Facultad de Ciencias Veterinarias, 2021.Facultad de Ciencias Veterinaria

Whole genome sequencing and de novo assembly of Staphylococcus pseudintermedius: a pangenome approach to unravelling pathogenesis of canine pyoderma

Background Staphylococcus pseudintermedius is the main aetiological agent of canine pyoderma. Whole genome sequencing is the most comprehensive way of obtaining relevant genomic information about micro-organisms. Hypothesis/Objectives Oxford Nanopore technology enables quality sequencing and de novo assembly of the whole genome of S. pseudintermedius. Whole genome analysis of S. pseudintermedius may help to better understand the pathogenesis of canine pyodermas. Methods and materials Twenty-two strains of S. pseudintermedius isolated from the skin of five healthy dogs and 33 strains isolated from skin of 33 dogs with pyoderma were analysed. DNA was extracted and sequenced using Oxford Nanopore MinION, a new technology that delivers longer reads in a hand-held device. The pangenome was analysed and visualised with Anvi’o 6.1. Results Nanopore technology allowed the sequencing and de novo assembly of the genomes of 55 S. pseudintermedius strains isolated from healthy dogs and from dogs with pyoderma. The average genome size of S. pseudintermedius was 2.62 Mbp, with 48% being core genome. Pyoderma isolates contained a higher number of antimicrobial resistance genes, yet the total number of virulence factors genes did not change between isolates from healthy dogs and from dogs with pyoderma. Genomes of meticillin-resistant S. pseudintermedius (MRSP) strains were larger than those of meticillin-susceptible (MSSP) strains (2.80 Mbp versus 2.59 Mbp), as a consequence of a greater presence of antimicrobial resistance genes, phages and prophages. Conclusions and clinical importance This technique allows much more precise and easier characterisation of canine S. pseudintermedius populations and may lead to a better understanding of the pathogenesis of canine pyodermas.info:eu-repo/semantics/publishedVersio

Caracterización de una fuente UV-C de bajo costo y alta eficiencia germicida para la esterilización de superficies e implementos de uso crítico diario: impacto en la salud pública

Mediante la modificación y caracterización de una lámpara comercial de mercurio halogenado de bajo costo, se diseñó una fuente UV-C altamente eficiente que posee un poder germicida igual o superior a fuentes UV-C comerciales diseñadas para tal fin. Desde un punto de vista físico, la ventaja de usar este tipo de lámparas es que presentan un amplio espectro de radiación UV: UV-A, UV-B y UV-C. Este último caso, en particular, la denominada zona germicida presenta un espectro de emisión con múltiples líneas, con longitudes de onda que van desde los 220 hasta los 280 nm; en particular, presentan máximos de emisión de las líneas espectrales con longitudes de onda entre 235 y 260 nm que destruyen tanto el ADN como las proteínas. Los resultados que se presentan son el resultado de estudios preliminares desarrollados en el laboratorio, en los cuales se irradiaron muestras que contenían bacterias in vitro, y se encontró una esterilización efectiva para tiempo de exposición por debajo de los 60 s para una distancia fuente-muestra de 35 cm y con una densidad de energía UV-C estimada de 1 W.s/m 2 . Los resultados obtenidos indican que el dispositivo construido con elementos de muy bajo costo y de fácil implementación es apto para la desinfección de superficies y recuperación de material descartable

Opportunities and challenges in antimicrobial resistance policy including animal production systems and humans across stakeholders in Argentina: a context and qualitative analysis

Introduction: Gaps in antimicrobial resistance (AMR) surveillance and control, including implementation of national action plans (NAPs), are evident internationally. Countries’ capacity to translate political commitment into action is crucial to cope with AMR at the human–animal–environment interface. Methods: We employed a two-stage process to understand opportunities and challenges related to AMR surveillance and control at the human–animal interface in Argentina. First, we compiled the central AMR policies locally and mapped vital stakeholders around the NAP and the national commission against bacterial resistance. Second, we conducted qualitative interviews using a semistructured questionnaire covering stakeholders’ understanding and progress towards AMR and NAP. We employed a mixed deductive–inductive approach and used the constant comparative analysis method. We created categories and themes to cluster subthemes and determined crucial relationships among thematic groups. Results: Crucial AMR policy developments have been made since 1969, including gradually banning colistin in food-producing animals. In 2023, a new government decree prioritised AMR following the 2015 NAP launch. Our qualitative analyses identified seven major themes for tackling AMR: (I) Cultural factors and sociopolitical country context hampering AMR progress, (II) Fragmented governance, (III) Antibiotic access and use, (IV) AMR knowledge and awareness throughout stakeholders, (V) AMR surveillance, (VI) NAP efforts and (VII) External drivers. We identified a fragmented structure of the food production chain, poor cross-coordination between stakeholders, limited surveillance and regulation among food-producing animals and geographical disparities over access, diagnosis and treatment. The country is moving to integrate animal and food production into its surveillance system, with most hospitals experienced in monitoring AMR through antimicrobial stewardship programmes. Conclusion: AMR accountability should involve underpinning collaboration at different NAP implementation levels and providing adequate resources to safeguard long-term sustainability. Incorporating a multisectoral context-specific approach relying on different One Health domains is crucial to strengthening local AMR surveillance