Actividad in vitro de agentes antimicrobianos sobre Staphylococcus aureus meticilino resistente (MRSA): evaluación comparativa del método e-test y dilución en tubo

Staphylococcus aureus con resistencia a meticilina (MRSA) es un patógeno para el ser humano que actualmente se encuentra entre los principales lugares como causa de infecciones en pacientes internados dentro de los nosocomios. Este patógeno, en los últimos años, ha tenido mayor presencia en infecciones en la comunidad. Es capaz de producir una gran variedad infecciones, desde aquellas relativamente fáciles de curar hasta infecciones de pronóstico severo si no se administra un tratamiento oportuno. Esta bacteria, a través de los años, ha venido adquiriendo resistencia hacia muchos tipos de antimicrobianos, imposibilitando su tratamiento, lo que se ha reflejado en un aumento en la morbilidad y mortalidad de los pacientes. Debido a la importancia que tiene esta bacteria en los centros médicos y a su continua habilidad para resistir el efecto de los antimicrobianos, fue que se realizó el presente trabajo. Se llevó acabo un análisis para determinar la incidencia de este patógeno en el interior de la Unidad Médica de Alta Especialidad (UMAE) # 25 IMSS de la ciudad de Monterrey, además de determinar sus patrones de resistencia a distintos agentes antimicrobianos. Para lograr tal análisis se llevaron a cabo las técnicas de E-test y dilución en tubo y se determinó la correlación de ambas técnicas para la determinación de resistencia. Los agentes examinados fueron aquéllos de uso tradicional, como es la eritromicina, ciprofloxacina, levofloxacina y gatifloxacina, así como aquéllos de uso reciente, tales como el linezolid, vancomicina, teicoplanina, quinupristin-dalfopristin y daptomicina. Se observó un 59 % de presencia de MRSA entre las cepas de S. aureus analizadas. Asimismo, se observó mayor actividad de los compuestos de uso reciente sobre los de uso tradicional. Los agentes linezolid, teicoplanina, vancomicina, daptomicina y quinupristin- alfopristin fueron los de mayor actividad en contra de MRSA, obteniéndose porcentajes de susceptibilidad de 95 % para daptomicina y quinupristin-dalfopristin y de 100 % para linezolid, teicoplanina y vancomicina, mientras que los agentes eritromicina, gatifloxacina, ciprofloxacina y levofloxacina fueron los menos eficiente con promedios de resistencia de 92%, 87%, 91%, 90% respectivamente. Se pudo observar el fenómeno de tolerancia en un 12% hacia los antimicrobianos de último recurso contra MRSA, como lo son vancomicina y teicoplanina. Por último, se concluyó que los resultados obtenidos mediante la técnica de E-test tienen correlación con los obtenidos meditante la dilución en tubo en la determinación de los patrones de susceptibilidad antimicrobiana para cepas de MRSA. Abstract Methicillin-resistant Staphylococcus aureus (MRSA) is a pathogenic bacterium to humans that is currently among the top places of cause of infections in patients committed within the hospitals, also in recent years it has had greater presence in community infections. MRSA is able to produce a great variety of infections, from those relatively easy to cure to infections of severe prognosis if an opportune treatment is not administered. Through the years, this bacterium has been acquiring resistance towards many types of antimicrobial agents disabling its treatment, which has been reflected in an increase in the morbidity and mortality of the patients. The present research has emerged due to the importance that this bacterium has in health facilities and to their continuous ability to resist the effect of the antimicrobial agents. An analysis to determine the incidence of this pathogen inside the Unidad Médica de Alta Especialidad (UMAE) # 25 IMSS in the city of Monterrey took place, to determine the pathogen’s patterns of resistance to different antimicrobial agents. In order to obtain such analysis the E-test and broth dilution techniques were carried out, and the correlation of both techniques of resistance were determined. The examined agents were those of traditional use as it is erythromycin, ciprofloxacin, levofloxacin and gatifloxacin, as well as those of recent use such as linezolid, vancomicyn, teicoplanin, quinupristin/dalfopristin and daptomycin. We observed the presence of 59 % of MRSA between the strains of S. aureus analyzed. Also greater activity of compounds of recent use was observed against those of traditional use. The agents linezolid, teicoplanin, vancomycin, daptomycin and quinupristin/dalfopristin were those of greater activity against MRSA obtaining percentage of susceptibility of 95 % for daptomycin and quinupristin/dalfopristin and of 100 % for linezolid, teicoplanin and vancomycin, whereas for the agents erythromycin, gatifloxacin, ciprofloxacin and levofloxacin were less efficient with averages of resistance of 92 %, 87 %, 91%, 90 % respectively. The phenomenon of tolerance could be observed in a 12 % towards the antimicrobial agents of last resource against MRSA, as they are vancomicyn and teicoplanin. Finally, it was concluded that the results obtained by means of the E-test technique have correlation with those obtained with the broth dilution technique in the determination of the patterns of antimicrobial susceptibility for MRSA strains

Reproductive characterization of hair ewe in the American tropics: a review part 1

Objective: to make a reproductive characterization of the hair sheep breeds in the American tropics. Design/methodology/approach: reproductive variables information was collected from scientific search engines, such as Web of Science, Redalyc, Dialnet, PubMed, SciELO and Latindex. Results: the age of puberty in ewe lambs is highly variable. Similar results were found in adult ewes regarding estrus duration and incidence, estrous cycle length, seasonal anestrus, ovulation rate, fertility, gestation, and prolificacy. Limitations on study/implications: information on reproductive variables of hair sheep breeds is poorly known or non-existent. Findings/conclusions: puberty onset in ewe lambs ranges from 175 to 335 d of age when animals weight 15 to 43 kg. The length of the estrous cycle of hair sheep in Mexico is 17 d during the autumn-winter and 21 d in spring-summer. In Brazil, it lasts 17 d in spring-summer and 18 d in autumn-winter. In the United States of America and Venezuela, the estrous cycle length was similar in both periods of the year. The estrous occurrence was 97.1% in autumn-winter and 76.5 % in spring-summer. The estrous duration ranges from 16 to 52 hours. Seasonal anestrous occurs from May to July. The ovulation rate ranges from 1 to 3 oocytes. Fertility is 80 to 100 % in temperate and 37 % in warm months. Gestation length ranges from 144 to 152 d. Prolificacy ranges from 1.0 to 2.2 offspring per ewe. The lambing interval range from 244 to 294 d.Objective: To carry out a reproductive characterization of the breeds of hair ewe in the tropical region of the Americas. Design/Methodology/Approach: A search of scientific information about the reproductive variables of breeds of hair ewe was carried out and the results were analyzed in the Web of Science, Redalyc, Dialnet, PubMed, SciELO, and Latindex databases. Results: We described and discussed the highly-variable onset of puberty in ewe lambs. Similar results were found in adult ewes regarding the duration and occurrence of the estrous, estrous cycle length, seasonal anestrous, ovulation rate, fertility, gestation, and prolificacy. Study Limitations/Implications: Information about the reproductive variables of breeds of hair ewe is poorly known or non-existent. Findings/Conclusions: The onset of puberty in 15-43 kg ewe lambs ranges from 175 to 335 d of age. The estrous cycle of hair ewe in Mexico lasts 17 d in autumn-winter and 21 d in spring-summer. In Brazil, this cycle lasts 17 d in spring-summer and 18 d in autumn-winter. In the United States of America and Venezuela, the estrous cycle length was similar in both periods of the year. The occurrence of the estrous reached 97.1 % in autumn-winter and 76.5 % in spring-summer. The duration of the estrous ranges from 16 to 52 hours. Seasonal anestrous occurs from May to July. The ovulation rate ranges from 1 to 3 oocytes. The percentage of fertility fluctuates between 80 and 100 % in temperate months and reaches 37 % in warm ones. Gestation lasts from 144 to 152 d. Prolificacy ranges from 1.0 to 2.2 offspring per ewe. The lambing interval ranges from 244 to 294 d

Determinación de la capacidad antioxidante total de alimentos y plasma humano por fotoquimioluminiscencia: Correlación con ensayos fluorométricos (ORAC) y espectrofotométricos (FRAP)

The determination of antioxidant capacity is useful to value the quality of a food, the sum of antioxidants in a system, or the bioavailability of antioxidant compounds in the human body. The available methods determine the potential effect of antioxidant substances, present in food and in the human body, against oxidation reactions. The objective was to compare the total antioxidant capacity (TAC) of food samples and human plasma, by photochemiluminescence (PCL) in contrast to methods that quantify the oxygen radical absorbance capacity (ORAC) and ferric reducing antioxidant power (FRAP). Water-soluble and lipid-soluble extracts were obtained from stabilized rice bran (SRB) and Ulva clathrata flour (UCF). Plasma was obtained from blood human samples (HUP). Three samples were processed in each case. The results were analyzed with one-way analysis of variance and Pearson's correlation, p <0.05. The results of TAC measurement were PCL, SRB 246.37 ± 5.37; UCF 21.05 ± 0.41 and HUP 90.59 ± 1.17 Trolox equivalents (TE) μmol /100 g or 100 mL, p<0.05. With ORAC were: SRB 5015.62 ± 12.83; UCF 852.37 ± 3.45 and HUP 2563.31 ± 39.47 TE μmol /100 g or 100 mL, p<0.05. FRAP: SRB 519.37 ± 0.04; UCF 52.78 ± 0.01 and HUP 90.26 ± 0.01 Fe2+ equivalents (Fe2+E) µmol /100 g or 100 mL. Correlations were observed between PCL-ORAC r=0.99; and PCL-FRAP r=0.94, both statistically significant (p < 0.05). PCL showed to be a reliable and alternative method to quantify TAC, which can be applied in food and health intervention studies.La determinación de la capacidad antioxidante es útil para valorar la calidad de un alimento, la cantidad de antioxidantes presentes en un sistema, o la biodisponibilidad de compuestos antioxidantes en el cuerpo humano. Los métodos disponibles realizan la determinación del efecto potencial de las sustancias antioxidantes, presentes en los alimentos y en el organismo humano, contra las reacciones de oxidación. El objetivo fue comparar los resultados de la detección de la capacidad antioxidante total (CAT) en muestras de alimentos y plasma humano, mediante la quimioluminiscencia por fotosensibilización (PCL), en contraste con métodos que cuantifican la capacidad de absorbancia del radical de oxígeno (ORAC) y el poder antioxidante reductor del hierro (FRAP). Se obtuvieron extractos hidrosolubles y liposolubles de salvado de arroz estabilizado (SAE) y de harina de Ulva clathrata (HUC). El plasma se obtuvo de muestras de sangre humana (PHU). Se procesaron tres muestras en cada caso. Los resultados se analizaron mediante análisis de varianza de una vía y correlación de Pearson, p < 0.05. La CAT determinada mediante PCL fue: SAE 246.37 ± 5.37, HUC 21.05 ± 0.41 y PHU 90.59 ± 1.17 equivalentes Trolox (ET) μmol /100 g ó 100 mL, p < 0.05; ORAC: SAE 5015.62 ± 12.83, HUC 852.37 ± 3.45 y PHU 2563.31 ± 39.47 ET μmol /100 g ó 100 mL, p < 0.05. FRAP: SAE 519.37 ± 0.04, HUC 52.78 ± 0.01 y PHU 90.26 ± 0.01 equivalentes Fe2+ (EFe2+) µmol /100 g ó 100 mL. Se observaron correlaciones entre PCL y ORAC, r = 0.99; y la PCL y FRAP, r = 0.94, ambas estadísticamente significativas (p < 0.05). La PCL mostró ser un método confiable y alternativo para cuantificar la CAT, que se puede aplicar en estudios de alimentos y de intervenciones en salud

Fases lunares e sua influência nas variáveis ​​reprodutivas de bovinos nos trópicos secos

Desde hace tiempo se especula que las fases lunares influyen en el comportamiento reproductivo de los animales. Se realizó un estudio para esclarecer la influencia de las fases lunares en la manifestación de estro, gestación, incidencia de partos y sexo de la cría en las vacas en el trópico seco mexicano. Los datos reproductivos de 580 vacas mestizas de 2010 al 2021 se organizaron según algunos eventos reproductivos (manifestación de estro, gestación, parto y sexo de las crías) ocurridos en las fases lunares (luna nueva, cuarto menguante, luna llena y cuarto creciente). La luna llena redujo la incidencia de estros (p&lt;0.05). La gestación, frecuencia de partos y sexo de las crías no fueron influenciadas por las fases lunares (p&gt;0.05). Se concluye que la luna llena reduce la manifestación de estros en vacas mestizas.Se especula que las fases lunares influyen en el rendimiento reproductivo de los animales. Se llevó a cabo un estudio para arrojar luz sobre la influencia de las fases lunares en la presentación del estro, la gestación, la presentación del parto y el sexo de la descendencia en vacas de la región tropical seca mexicana. Los datos reproductivos de 580 vacas cruzadas de 2010 a 2021 se organizaron de acuerdo con los eventos reproductivos (presentación del celo, gestación, presentación del parto y sexo de la descendencia) durante las fases lunares (luna nueva, primer trimestre, luna llena y último trimestre). La luna llena redujo la presentación del estro (p&lt;0.05). La gestación, la presentación del parto y el sexo de la descendencia no fueron influenciados por las fases lunares (p&gt;0.05). Se concluye que la luna llena reduce la presentación del estro en vacas cruzadas.Há muito se especula que as fases lunares influenciam o comportamento reprodutivo dos animais. Foi realizado um estudo para esclarecer a influência das fases lunares na manifestação do estro, gestação, incidência de parto e sexo dos bezerros em vacas nos trópicos secos mexicanos. Os dados reprodutivos de 580 vacas mestiças de 2010 a 2021 foram organizados de acordo com alguns eventos reprodutivos (manifestação de estro, gestação, parto e sexo dos bezerros) que ocorreram nas fases lunares (lua nova, quarto minguante, lua cheia e primeiro quarto). A lua cheia reduziu a incidência de estro (p&lt;0,05). A gestação, frequência de nascimento e sexo dos filhotes não foram influenciados pelas fases lunares (p&gt;0,05). Conclui-se que a lua cheia reduz a manifestação de estro em vacas mestiças

Production of corn plus sunflower forage and its preference as silaged by sheep in Mineral de la Reforma, Hidalgo

a) Objective. The objective was to evaluate the forage production of maize, maize + sunflower and its preference for sheep as silage. b) Design/methodology/approach. The design in the field was in completely randomized blocks with three replications and in the laboratory in a completely randomized design (Tukey α = 0.05). Sowing was in spring - summer 2020 under rainfed conditions. The treatments were: 100 % corn, 90 % corn + 10 % sunflower, 80 % corn + 20 % sunflower. Forage production was evaluated at 126 days of sowing, it was ensiled and the quality through bromatological analysis. For silage preference, 10 pregnant Hampshire × Suffolk ewes were used with 44.8 kg of live weight along 20 days. c) Results. The 80 % maize + 20% sunflower combination showed higher green forage yield (P&lt;0.001; 28 t ha-1), higher percentage of soluble protein (P&lt;0.01) and higher percentage of lignin (P&lt;0.001; 4.6 %). The sheep preferred the silage with 100 % corn, since it had a lower percentage of non-fibrous carbohydrates (22.2 %), lower acid detergent fiber (35.3 %) and lower neutral detergent fiber (59.4 %). d) Limitations/implications. Sunflower should be established on soils with low numbers of broadleaf plant seeds, because chemical control cannot be applied. e) Findings/conclusions. A greater amount of forage was produced per surface unit whit 80 % corn + 20 % sunflower. The 100 % maize silage was preferred by sheep due to lower percentage of lignin, and higher in vitro digestibility of neutral detergent fiber