Agentes infecciosos de Litopenaeus vannamei (Boone, 1931) y su relación con parámetros físicoquímicos de tres diferentes sistemas de cultivo en el golfo de México.

La producción de camarón aumentó de 33.480 toneladas por año en 2000-2001 a 128 000 t en el período 2008-2009, lo que representa el 69% de la producción total en México. Se colectaron muestras de L. vannamei desde 2008 hasta 2009, durante dos ciclos de producción de tres granjas de camarón en el estado de Tamaulipas. Durante el ciclo 2009, se analizaron un total de 600 organismos; 180 de Reynosa, 180 de La Pesca, y 240 de Morón. Se midio el oxígeno disuelto (OD, mg/L) y la temperatura (°C) dos veces al día (mañana y noche). La salinidad, el pH y la turbidez del agua se midieron diariamente. Durante el ciclo de cultivo del 2008, un total de 660 organismos fueron muestreados. Este estudio representa el primer registro geográfico de la presencia de L. mucor, Zoothamnium sp, Epistylis sp, Acineta sp y Nematopsis sp en L. vannamei de piscifactorías en Tamaulipas

Descripción de la microbiota de los cipríndos (Cyprinus carpio) de la laguna de Salinillas, Anáhuac, Nuevo León, México.

La carpa por su volumen se encuentra posicionada en el lugar 11 de la producción pesquera en México; la tasa media de crecimiento anual en los últimos 10 años es de -1.78%. Se han reportado diversos microorganismos patógenos de carpas, por lo que el presente estudio se centra en describir la microbiota de los ciprínidos de la región. Las muestras de piel, aletas, branquias y órganos internos (riñones, hígado e intestino), se inocularon agar soya tripticasa, agar McConkey y medio Rimler-Shotts. Los aislados se identificaron con API 20E y NFT. La patogenicidad se determinó en lotes de 10 carpas asintomáticos en el laboratorio, como controles se usaron peces no inoculados y peces inoculados con cultivo estéril. La microbiota aislada correspondió a enterobacterias (100%), Pseudomonas sp. (100%), Aeromonas sp. (100%), Alcaligenes sp. (25%), Moraxella sp. (21.4%), Plesiomonas sp. (17.8%), Xanthomonas sp. (39.28%), Acinetobacter calcoaceticus (17.85%) y Achromobacterium anitratus (3.57%). De las cepas analizadas Aeromonas sobria, A. caviae, A. hydrophila, Pseudomonas fluorescens, Alcaligenes sp y Plesiomonas sp presentaron un 100% de mortalidad en los bioensayos

Interacciones temporales y espaciales de mesocarnívoros simpátricos en una Reserva de la Biosfera: ¿coexistencia o competencia?

Abstract: Temporal and spatial interactions of sympatric mesocarnivores at a Biosphere Reserve: coexistence or competition? Interspecific interactions among tropical mesocarnivorous species and other mammalian trophic guilds have been poorly studied, despite they have important implications in the survival, structure, demography, and distribution of these species. In this study we analyzed spatio-temporal interactions of three sympatric mesocarnivores that are located in the Northeastern limit of their geographic distribution in Mexico, with the objective of analyzing if these species coexist or compete in the axis of the temporal and spatial niche. With a sampling period from January 2015 to December 2016 and 26 camera-trapping stations (with in a set of two camera traps opposite to each other) and located along roads and animal trails, we determined the activity pattern and habitat use of L. wiedii (margay), L. pardalis (ocelote) y P. yagouaroundi (yaguarundi). All independent photographs of each species were grouped into three temporal categories (day, night and twilight) and six habitat categories; Oak Forest, Oak-Pine Forest, Cloud Forest, Pine-Oak Forest, Tropical Deciduous Forest and Medium Forest. Temporal and spatial overlap between species (i.e. interactions) was obtained with the Czekanowski index and the Pianka index, respectively. These indices are symmetrical and take values from zero to one, where the results close to zero indicate that there is no overlap between species and values close to one indicate overlap. We obtained a total of 379 independent photographs, of which 239 corresponded to margay, 118 to ocelot and 22 to yaguarundi. Margay and ocelot were nocturnal, with 75 % of their records in this category showing a high temporal overlap (0.85); whereas yaguarundi was fully diurnal, suggesting it may be able to coexist with the other two species (margay and ocelot). Moreover, the yaguarundi used habitat similar to ocelot and margay (with high spatial overlap of 0.81 and 0.72, respectively), while the spatial overlap between the margay and ocelot was intermediate (0.53), since they used in most cases different habitat types. Our results suggest that there is no interspecific competition among these tropical mesocarnivorous species, probably due to antagonistic interactions among them on the temporal and spatial axis. These strategies may positively favor populations of mesocarnivores, which are characterized by having a high territorial behavior. Rev. Biol. Trop. 66(3): 996-1008. Epub 2018 September 01. Key words: “El Cielo” Biosphere Reserve; Tamaulipas; Mexico; tropical felines; interespecific interaction

Synergistic Antimicrobial Effects of Silver/Transition-metal Combinatorial Treatments

Due to the emergence of multi-drug resistant strains, development of novel antibiotics has become a critical issue. One promising approach is the use of transition metals, since they exhibit rapid and significant toxicity, at low concentrations, in prokaryotic cells. Nevertheless, one main drawback of transition metals is their toxicity in eukaryotic cells. Here, we show that the barriers to use them as therapeutic agents could be mitigated by combining them with silver. We demonstrate that synergism of combinatorial treatments (Silver/transition metals, including Zn, Co, Cd, Ni, and Cu) increases up to 8-fold their antimicrobial effect, when compared to their individual effects, against E. coli and B. subtilis. We find that most combinatorial treatments exhibit synergistic antimicrobial effects at low/ non-toxic concentrations to human keratinocyte cells, blast and melanoma rat cell lines. Moreover, we show that silver/(Cu, Ni, and Zn) increase prokaryotic cell permeability at sub-inhibitory concentrations, demonstrating this to be a possible mechanism of the synergistic behavior. Together, these results suggest that these combinatorial treatments will play an important role in the future development of antimicrobial agents and treatments against infections. In specific, the cytotoxicity experiments show that the combinations have great potential in the treatment of topical infections

BIOPROSPECCIÓN DE LA ACTIVIDAD ANTIMICÓTICA DE EXTRACTOS METANÓLICOS DE ARIOCARPUS KOTSCHOUBEYANUS Y ARIOCARPUS RETUSUS

The antifungal activity of methanolic extracts from Ariocarpus kotschoubeyanusand A. retusus, two native xerophytes ofnortheastern Mexico, was determined onthe fungal dermatophytes Trichophytontonsurans, Microsporum canis and Microsporum cookei. Putative active metabolites were identified by phytochemicalscreening using evidence for functionalgroups; determination of antifungal activity was conducted by the disk-diffusion platemethod as part of the process of understanding the chemistry and efficacy of theseplant products. Doses tested were 125,250 y 500 mg/mL. Extracts were positivefor carbonyl groups, phenolic oxhidrils,sterols and methyl sterols, coumarins, sesquiterpenlactones, saponins, flavonoids andalkaloids. Extract from A. retusus (stem)yielded the greatest activity against Trichophyton tonsurans and Microsporum cookei.Univariate analysis of variance revealedthat with regard to antifungal activity therewere significant differences between fungi,culture media and analyzed doses withrespect to positive control of ketoconazole.These results served to validate empiricalknowledge about these plants in traditionalmedicine. These studies form a basis forfurther research in the search for bioactivecompounds and the discovery of potentialherbal medicaments.Se determinó la actividad antifúngica invitro de extractos metanólicos de Ariocarpus kotschoubeyanus y Ariocarpusretusus, plantas xerófitas del noreste delpaís, usadas en la medicina tradicional,sobre los hongos dermatofitos Trichophytontonsurans, Microsporum canis y Microsporum cookei. Los metabolitos presentes seidentificaron por tamizaje fitoquímico empleando pruebas para grupos funcionales, ladeterminación de actividad antifúngica serealizó por el método de difusión en placaempleando microdiscos, con la finalidadde entender la química y eficacia de estosproductos vegetales, las dosis evaluadasde estos extractos fueron 125, 250 y 500mg/mL. Los extractos resultaron positivospara grupos carbonilo, oxidrilos fenólicos,esteroles y metilesteroles, cumarinas, sesquiterpenlactonas, saponinas, flavonoides yalcaloides. El extracto que presentó mayoractividad fue el de Ariocarpus retusus(tallo) contra Trichophyton tonsurans y Microsporum cookei. El análisis estadístico devarianza univariante reveló que en cuantoa la actividad antifúngica, existe diferencia significativa entre hongos, medios de cultivo y dosis evaluadas de los extractos conrespecto al control positivo de ketoconazol.Estos resultados sirvieron para validar elconocimiento empírico que se tiene acercade estas plantas en la medicina tradicional.Siendo estos estudios una base para nuevas investigaciones sobre la búsqueda decompuestos bioactivos y el descubrimientode medicamentos potenciales de productosherbales

Antiviral mode of action of bovine dialyzable leukocyte extract against human immunodeficiency virus type 1 infection

<p>Abstract</p> <p>Background</p> <p>Bovine dialyzable leukocyte extract (bDLE) is derived from immune leukocytes obtained from bovine spleen. DLE has demonstrated to reduce transcription of Human Immunodeficiency Virus Type 1 (HIV-1) and inactivate the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway. Therefore, we decided to clarify the mode of antiviral action of bDLE on the inhibition of HIV-1 infection through a panel of antiviral assays.</p> <p>Results</p> <p>The cytotoxicity, HIV-1 inhibition activity, residual infectivity of bDLE in HIV-1, time of addition experiments, fusion inhibition of bDLE for fusogenic cells and the duration of cell protection even after the removal of bDLE were all assessed in order to discover more about the mode of the antiviral action.</p> <p>HIV-1 infectivity was inhibited by bDLE at doses that were not cytotoxic for HeLa-CD4-LTR-β-gal cells. Pretreatment of HIV-1 with bDLE did not decrease the infectivity of these viral particles. Cell-based fusion assays helped to determine if bDLE could inhibit fusion of Env cells against CD4 cells by membrane fusion and this cell-based fusion was inhibited only when CD4 cells were treated with bDLE. Infection was inhibited in 80% compared with the positive (without EDL) at all viral life cycle stages in the time of addition experiments when bDLE was added at different time points. Finally, a cell-protection assay against HIV-1 infection by bDLE was performed after treating host cells with bDLE for 30 minutes and then removing them from treatment. From 0 to 7 hours after the bDLE was completely removed from the extracellular compartment, HIV-1 was then added to the host cells. The bDLE was found to protect the cells from HIV-1 infection, an effect that was retained for several hours.</p> <p>Conclusions</p> <p>bDLE acted as an antiviral compound and prevented host cell infection by HIV-1 at all viral life cycle stages. These cell protection effects lingered for hours after the bDLE was removed. Interestingly, bDLE inhibited fusion of fusogenic cells by acting only on CD4 cells. bDLE had no virucidal effect, but could retain its antiviral effect on target cells after it was removed from the extracellular compartment, protecting the cells from infection for hours.</p> <p>bDLE, which has no reported side effects or toxicity in clinical trials, should therefore be further studied to determine its potential use as a therapeutic agent in HIV-1 infection therapy, in combination with known antiretrovirals.</p