Términos relacionados

402 resultados encontrados para: TEMA: Parásitos
  • «
  • 1 de 41
  • »
1.
Tesis
A longuitudinal field study of the epidemiology of intestinal helminthoses in relation to the dieatry and therapeutic ingestion of chenopodium spp. among the maya of Chiapas state, México / Michael Mckinnon Kliks
Kliks, Michael Mckinnon (autor) ;
San Diego, California, United States : University of California , s.f.
Clasificación: CH/614.553 / K5
Bibliotecas: San Cristóbal
Cerrar
SIBE San Cristóbal
SFA000453 (Disponible)
Disponibles para prestamo: 1

2.
Artículo
PDF
Resumen en: Inglés |
Resumen en inglés

The oceanographic conditions of the Pacific Ocean are largely modified by El Niño (EN), affecting several ecological processes. Parasites and other marine organisms respond to environmental variation, but the influence of the EN cycle on the seasonal variation of parasitic copepods has not been yet evaluated. We analysed the relation between infection parameters (prevalence and mean intensity) of the widespread parasitic copepods Caligus bonito and Charopinopsis quaternia in the dolphinfish Coryphaena hippurus and oceanography during the strong 2015–16 EN. Fish were collected from capture fisheries on the Ecuadorian coast (Tropical Eastern Pacific) over a 2-year period. Variations of sea surface temperature (SST), salinity, chlorophyll a (Chl-a), Oceanic Niño Index (ONI), total host length (TL) and monthly infection parameters of both copepod species were analysed using time series and cross-correlations.

We used the generalised additive models for determine the relationship between environmental variables and infection parameters. The total body length of the ovigerous females and the length of the eggs of C. bonito were measured in both periods. Infection parameters of both C. bonito and Ch. quaternia showed seasonal and annual patterns associated with the variation of environmental variables examined (SST, salinity, Chl-a and ONI 1+2). Infection parameters of both copepod species were significantly correlated with ONI 1+2, SST, TL and Chl-a throughout the GAMLSS model, and the explained deviance contribution ranged from 16%-36%. Our results suggest than an anomaly higher than +0.5°C triggers a risen in infection parameters of both parasitic copepods. This risen could be related to increases in egg length, female numbers and the total length of the ovigerous females in EN period. This study provides the first evidence showing that tropical parasitic copepods are sensitive to the influence of EN event, especially from SST variations. The observed behaviour of parasitic copepods likely affects the host populations and structure of the marine ecosystem at different scales.


3.
Artículo
PDF
Resumen en: Inglés |
Resumen en inglés

This study was aimed at evaluating thein vitroeffect of the edible mushroom (EM) Pleurotus eryngiiagainst the eggs and larvae (L3) of Haemonchus contortus. The evaluation included acetone (AE) and hydroalcoholic (HA) extracts of the following strains: ECS-1138, ECS-1156, ECS-1255, ECS-1258, ECS-1261, ECS-1282, and ECS-1292. The HA extract of the ECS-1255 strain showed thehighest effect on mortality rates of L3 (18.83%) at 20 μg/mL. After subjecting this HA extract to a normal phase chromatography column, five fractions were obtained; fraction F5 (100% MeOH) was the most effective against eggs, with hatching inhibition percentages of 88.77 and 91.87% at 20 and 40 mg/mL, respectively. Gas chromatography-mass spectrometry (GC-MS) subjected this fraction to an acetylation reaction to determine the content of the secondary metabolites. The GC-MSanalysis showed that the F5 fraction was composed of trehalose CAS: 6138-23-4, polyols (L-iditol CAS: 488-45-9, galactitol CAS:608-66-2, D-mannitol CAS: 69-65-8, D-glucitol CAS: 50-70-4, and myoinositol CAS: 87-89-8), adipic acid CAS: 124-04-9, stearic acid CAS: 57-11-4, squalene CAS: 111-02-4, and β-sitosterol CAS: 83-46-5.


4.
Artículo
*Solicítelo con su bibliotecario/a
In vitro nematocidal activity of commercial fatty acids and β-sitosterol against Haemonchus contortus
Pineda Alegría, Jesús Antonio (autor) ; Sánchez, José E. (autor) ; González Cortázar, Manáses (autor) ; Von Son de Fernex, Elke (autora) ; González Garduño, Roberto (autor) ; Mendoza de Gives, Pedro (autor) ; Zamilpa, Alejandro (autor) ; Aguilar Marcelino, Liliana (autora) ;
Contenido en: Journal of Helminthology Vol. 94, e135 (2020), p. 1-4 ISSN: 1475-2697
Nota: Solicítelo con su bibliotecario/a
Resumen en: Inglés |
Resumen en inglés

Haemonchus contortusis a haematophagous gastrointestinal nematode (GIN) that causes severe anaemia and even death in small ruminants, negatively impacting the economic viability of farms. Traditionally, this parasite has been controlled with chemical compounds; however, inadequate use of these types of products has favoured the emergence of anthelmintic resistance. Therefore, it is necessary to search for alternatives for GIN control. Previous studies have reported the anthelmintic activity of edible mushroom extracts against H. contortus. A recent study reported that a fraction constituted of different fatty acids and β-sitosterol isolated from the basidiomata of the edible mushroom Pleurotus djamor ECS-123 has ovicidal and larvicidal activity against H. contortus. Thus, this study aimed to assess the anthelmintic activity of the pure molecules: pentadecanoic acid, palmitic acid, β-sitosterol, stearic acid and linoleic acid. For this purpose, an egg-hatching inhibition test was carried out in which the compounds were evaluated individually and in combination at a final concentration of 20 mg mL−¹. Furthermore, larval mortality was assessed using a combination of the five commercial compounds previously mentioned at different concentrations (1.25–20 mg mL−¹). Palmitic acid and stearic acid, in some combinations, inhibited H. contortus egg hatching by 100%. On the other hand, in the larval mortality test, the combination of the five compounds showed dose-dependent behaviour, and 100% mortality was obtained 24 h post-incubation. Pure molecules and their combinations have anthelmintic-like activity against the eggs and larvae of H. contortus.


PDF

6.
- Artículo con arbitraje
*Solicítelo con su bibliotecario/a
A comparison of sexual competitiveness and demographic traits of Anastrepha obliqua (Macquart) (Diptera: Tephritidae) among fruit-associated populations
Hernández Ortiz, Emilio (autor) ; Ruiz Montoya, Lorena (autora) (1964-) ; Toledo, Jorge (autor) ; Montoya Gerardo, Pablo Jesús (autor) ; Montoya Gerardo, Pablo Jesús (autor) ; Liedo Fernández, Pablo (autor) ; Aceituno Medina, Marysol (autora) ; Perales Rivera, Hugo Rafael (autor) ;
Disponible en línea
Contenido en: Bulletin of Entomological Research Vol. 109, no. 3 (June 2019), p. 333-341 ISSN: 1475-2670
Nota: Solicítelo con su bibliotecario/a
Resumen en: Inglés |
Resumen en inglés

The control of Anastrepha obliqua includes the sterilization of mass-reared insects grown in isolation in a constantly controlled environment. Through time, laboratory mass-reared colonies may produce flies with lower field performance. To recover the genetic variation and aptitude of mass-reared populations, wild insects are introduced into mass-reared colonies. Our aim in this study was to determine whether the host species from two localities influence the life history traits of A. obliqua. We collected flies as larvae from infested fruits of Spondias purpurea, S. mombin, Mangifera indica cv. 'piña', and M. indica cv. 'coche' from two localities in Chiapas, Mexico. There were significant differences in the mating competitiveness of males collected from mango cv. 'coche' compared with mass-reared males. There were no differences in the mating propensity between flies from the two localities, even in the number of matings, when weight was considered as a covariable. The mass-reared strain showed the earliest age at first oviposition. The locality affected the longevity and oviposition period, and these influenced the birth rate, intrinsic rate of increase, finite rate of population increase, mean generation time, and doubling time. According to the demographic parameters, the population of S. mombin would allow artificial colonization in less time, considering that it has a high reproduction rate starting at an early age. Even in the propensity test, it had the highest number of matings. However, males with greater sexual competitiveness and longevity for colonization corresponded to those collected from S. purpurea.


7.
Artículo
*Solicítelo con su bibliotecario/a
First description of the male and subgravid female of Philometra serranellicabrillae Janiszewska, 1949 (Nematoda: Philometridae), a gonad-infecting parasite of the comber Serranus cabrilla (Linnaeus) (Serranidae) off Tunisia
Ghanmi, Nessrine (autora) ; González Solís, David (autor) ; Gargouri, Lamia (autora) ;
Contenido en: Systematic Parasitology Vol. 96, no. 8 (2019), p. 673–679 ISSN: 0165-5752
Nota: Solicítelo con su bibliotecario/a
Resumen en: Inglés |
Resumen en inglés

The male and subgravid female of Philometra serranellicabrillae Janiszewska, 1949 (Philometridae) collected from the gonads of Serranus cabrilla (Linnaeus) (Serranidae) off Tunisia are described for the first time based on light and scanning electron microscopical studies. The male of this nematode can be separated from other congeneric gonad-infecting nominal species in the structure and shape of the gubernaculum (e.g. absence of a dorsal protuberance and a median smooth field). The shape ofthe male posterior region is unique in that it bears apair of big circular papillae posterior to the cloacal opening, which is also present in other Philometra spp. from serranids, i.e. P. indica Moravec & Manoharan, 2014, P. inexpectata Moravec, Chaabane, Justine & Neifar, 2016 and P. jordanoi (López-Neyra, 1951) Yamaguti, 1961. Moreover, P. serranellicabrillae differs from its congeners in other fish families from the Mediterranean Sea, in the length of spicules and gubernaculum.


PDF PDF
Resumen en: Inglés |
Resumen en inglés

Background: We assessed metrics of the metazoan parasite infracommunities of the dusky founder (Syacium papillosum) as indicators of aquatic environmental health of the Yucatan Shelf (YS) prior to oil extraction. We sampled the dusky founder and its parasites along the YS, mostly during the 2015 north wind season (November–April). Our aims were: (i) to determine whether the parasite infracommunity metrics of S. papillosum exhibit signifcant diferences among YS subregions; (ii) to determine whether the probability of the occurrence of its parasite species and individu‑ als were afected by environmental variables, nutrients, heavy metals and hydrocarbons at the seascape level; and (iii) to determine whether there were statistical diferences between the parasite infracommunity metrics of S. papillosum from YS and those of Syacium gunteri from the Campeche Sound. Multivariate statistical analyses and generalised additive models (GAMs) were used to examine the potential statistical associations between the contaminants, environmental variables and parasite community metrics, and the maximum entropy algorithm (MaxEnt) was used to characterise the habitat’s suitability for the parasite’s probability of occurrence. Results: We recovered 48 metazoan parasite species from 127 S. papillosum, with larval cestodes and digeneans being the most numerically-dominant. Multivariate analyses showed signifcant diferences in parasite infracommu‑ nity metrics among Western YS, Mid YS and Caribbean subregions, with the latter being the richest in species but not in individuals. The GAM and MaxEnt results indicated a negative efect of top predators (e.g. sharks and rays) removal on parasite metrics. The parasite infracommunities of S. papillosum were twice as rich in the number of species and individuals as those reported for S. gunteri from the Campeche Sound.

Conclusions: The significant differences among subregions in parasite metrics were apparently due to the interruption of the Yucatan current during the north wind season. The fishing of top predators in combination with an influx of nutrients and hydrocarbons in low concentrations coincides with an increase in larval cestodes and digeneans in S. papillosum. The dusky founder inhabits a region (YS) with a larger number of metazoan parasite species compared with those available for S. gunteri in the Campeche Sound, suggesting better environmental conditions for transmis‑ sion in the YS.


9.
Artículo
*Solicítelo con su bibliotecario/a
The parasitic nematode Metaparasitylenchus hypothenemi interferes with the endoparasitoid Phymastichus coffea, in the biological control of the coffee berry borer
Castillo Vera, Alfredo (autor) ; Infante, Francisco (autor) ;
Contenido en: Biocontrol Science and Technology Vol. 29, no. 4 (2019), p. 388-392 ISSN: 1360-0478
Nota: Solicítelo con su bibliotecario/a
Resumen en: Inglés |
Resumen en inglés

We studied the interaction of Metaparasitylenchus hypothenemi with the exotic parasitoid Phymastichus coffea, when both natural enemies, co-ocurred inside the coffee berry borer adult. The nematode affects larvae and pupae ofP. coffea, reducing by ten times the parasitoid’s adult progeny. We concluded that the negative effect caused by M. hypothenemi on the survival and development of juvenile stages of P. coffea could affect the action of this parasitoid as a natural enemy of this pest.


10.
- Artículo con arbitraje
*Solicítelo con su bibliotecario/a
Parasitic nematodes in Snappers (Perciformes: Lutjanidae) from the Southern Gulf of Mexico and Mexican Caribbean
Hernández Olascoaga, Arturo (autor) ; González Solís, David (autor) ;
Contenido en: Journal of Parasitology Volumen 105, número 5 (October 2019), páginas 697-703 ISSN: 0022-3395
Nota: Solicítelo con su bibliotecario/a
Resumen en: Inglés |
Resumen en inglés

Snappers from the southern Gulf of Mexico (SGM) and Mexican Caribbean (CAR) were examined for parasitic nematodes to determine their richness, composition, and infection parameters (prevalence and mean intensity). From February 2016 to March 2018, 431 individuals of 8 snapper species were collected in 6 localities. In all, these fishes were parasitized by 2,275 individual nematodes belonging to 13 taxa: Terranova sp. was found in 7 of 8 host species and showed the highest prevalence (23%), while the rest had lower values (<10%). Lutjanus griseus (Linnaeus) harbored the highest species richness (10 species), followed by Lutjanus apodus (Walbaum) (8 species). Most localities were similar in terms of species richness but differed in the specific composition. Eight nematode taxa represent new host records for the family Lutjanidae (Gill), thus increasing to 22 the nematode taxa in the SGM and CAR. There is a potential risk to public health due to the presence of nematodes with zoonotic potential (as Anisakis sp.) and the habit in the region of eating raw fish (cebiche).