Population genetic analysis of Anisakis simplex s.l. and Anisakis pegreffii (Nematoda, Anisakidae) from parapatric areas and their contact zone.

Genetic markers (ribosomal DNA and mitochondrial DNA) were used for molecular dissection of the Anisakis simplex sensu lato (s.l). complex populations. Host fish were caught off Moroccan coasts, where only Anisakis pegreffii is present, the sympatric area comprising Spanish coasts, and the Little Sole Bank fishing area from Nordeast Atlantic Ocean where the only present species is A. simplex sensu stricto(s.s.). Sequence variations in the amplification products were then assessed indirectly by digestion with restriction endonucleases or directly by sequencing for 623 L3 larvae. The sequences were used to infer the relationships between the two species under study using various methodological approaches. We reveal the high genetic diversity of Anisakis simplex s.s. and A. pegreffii in both mitochondrial and nuclear genes. We detected 10 and 2 fixed differences between A. simplex s.s and A. pegreffii in the Cox2 and ITS1, respectively. We found a proportion of putative hybrids below 20% with similar figures on the Atlantic and Mediterranean coasts. Moroccan hybrids were more similar to A. pegreffii reflecting backcrosses between these mixed genotypes and his ancestor A. pegreffii. We discuss the possible interpretation of these putative hybrids.

Epidemiology and molecular identification of Anisakis pegreffii (Nematoda: Anisakidae) in the horse mackerel Trachurus trachurus from northern Morocco.

Anisakis infection parameters were studied in horse mackerel (Trachurus trachurus) taken from two areas of northern Morocco (Tetouan and Tangier), which showed a mean prevalence of 54.9%. Identification of the ITS1-5.8S-ITS2 fragment by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) showed A. pegreffii to be the dominant species; no A. simplex s.s. were detected. The presence of A. pegreffii in horse mackerel was not influenced by the sex (P = 0.46) or catch area (Atlantic versus Mediterranean, P = 0.52) of the fish, but was significantly related to their length, weight, liver weight and gonad weight, and to the season of their capture (P < 0.05). A low prevalence (8.6%) and mean intensity (1.0) was detected in the muscle, probably related to the reduced ability of A. pegreffii to penetrate muscle. The risk of the presence of A. pegreffii in the muscle was fivefold higher in fish caught during the summer than during any other season. Susceptible members of the human population can minimize the risk of infection by avoiding the consumption of larger horse mackerel specimens during the summer.

Sensitization to Anisakis simplex species in the population of northern Morocco.

OBJECTIVE: To investigate sensitization to third-stage Anisakis simplex larvae in a randomly selected population in northern Morocco. METHODS: We studied sera obtained from clinical analysis laboratories in Tangier and Tetuouan and from fishermen at Tangier port. The age of the study population ranged from 6 to 83 years. ImmunoCAP and immunoblotting techniques were used to determine total and specific immunoglobulin (Ig) E values and the chi2 and Fisher exact tests were applied to analyze relationships between study variables. RESULTS: A seroprevalence of 5.1% was found, with a higher percentage of positive sera in the 31-to-43-year age group. Sensitization was not significantly associated with the origin, sex, occupation, or age of the individuals studied. In sera positive by InmunoCAP, immunoblotting studies detected numerous bands of between 7 kDa and >209 kDa, with a predominance of bands in the approximately 20-kDa to 24-kDa range. CONCLUSIONS: Although no cases of human anisakiasis have been reported in Morocco to date, part of a randomly selected population in Northern Morocco shows sensitization to A simplex proteins.

Actividad IN VIVO del aceite esencial de Origanum elongatum frente a larvas L3 de Anisakis pegreffii / IN VIVO activity of essential oil Origanum elongatum against larva L3 of Anisakis pegreffii

En este trabajo se aborda la posible actividad larvicida in vivo del aceite esencial de Origanumelongatum, recolectado en Marruecos, frente a las larvas L3 de Anisakis pegreffii, que parasitan distintas especies marinas. Los resultados obtenidos son demostrativos del interés potencial de esteaceite esencial como preventivo de la infección por Anisakis, tras ingestión del pescado parasitado(AU)

Anisakiasis is an emerging zoonotic disease caused by species of the genus Anisakis. In humans, this parasite is manifested by digestive symptoms. In the virtual absence of effective treatments against this infection, our working group has initiated a series of investigations aimed at finding natural products such as essential oils and their major components, which might be of interest in the treatment of the infectious form of these zoonoses. OBJECTIVE: Establishment of the possible in vivo activity of essential oil of O. elongatum, against L3 larva of Anisakis pegreffii. METHODOLOGY: For the study in vivo, parasites were isolated from the host Scomber japonicas (mackerel) and Trachurus trachurus (horse mackerel). The experimental animals (female Wistar rats) were infected with 6 Anisakis larva by gastric catheter, this technique was used also for the administration of O. elongatum (46.9 mg / 0.5 ml of olive oil), according to the following guidelines: infection and joint treatment and sacrifice at 4 hours. Parallel to this, a control test was performed, administering 0.5 ml olive oil together with six larvae of the parasite to a group of animals. The identification of the larvae was carried out using molecular techniques (PCR-RFLP). The identification of the main components of essential oil was performed by GC-MS(AU)

Estudio epidemiológico de Anisakis tipo I en la bacaladilla (Micromesistius poutassou) del noroeste de España / Epidemiological study of Anisakis type I in blue whiting (Micromesistius poutassou) captured in northwestern Spain

Se ha estudiado la parasitación por Anisakis tipo I en 119 bacaladillas (Micromesistius poutasou) capturadas en el noroeste de España. La prevalencia total encontrada ha sido del 100% y la intensidad y abundancia medias de 55,89. También, se ha determinado los parámetros de infección en cavidad corporal, y musculatura hipoaxial e epiaxial. El mayor número de larvas aisladas ha correspondido a las vísceras (4808) y el menor a la musculatura epiaxial (343). Se ha observado un incremento de los parámetros de infección de acuerdo con la longitud del pez, siendo la intensidad y abundancia mediasde 32,47 para los peces entre 24-25 cm, de 57,00 para los de 26-27 cm y de 85,84 en los ≥ 28 cm de longitud(AU)

We have studied the parasitization by Anisakis type I in 119 blue whiting (Micromesistius poutasou)captured in Northwestern Spain. The overall prevalence found has been 100%, the mean values of intensity and abundance have been 55.89. The infection parameters have also been identified in the body cavity, and in hipoaxial and epaxial muscle. The highest number of isolated larvae has corresponded to the viscera (4808) and the lowest in the epaxial musculature (343). There has been anincrease in infection parameters according to the length of the fish, being the mean intensity and abundance 32.47 for fish between 24-25 cm, 57.00 for 26-27 cm and 85.84 in those ≥ 28 cm of length(AU)