Search Results

1 - 2 of 2 items

  • Author: N. Vovlas x
Clear All Modify Search
A polyphasic approach with molecular phylogeny for the characterization of Anisakis pegreffii (Anisakidae: Nematoda) in fishes from Adriatic Sea

Abstract

In this study we investigated the morphometric and molecular characterization of a liver encapsulated third-stage larval population of Anisakis spp. infecting Merluccius merluccius and Lophius piscatorius caught in the Adriatic Sea waters (southern Italy). A polyphasic approach based on PCR-RFLP profiles of the ITS region, mitochondrial COI (cytochrome c oxidase subunit 1), sequencing and molecular phylogeny of ITS and mitochondrial COI was used to identify Anisakis larvae collected from fish samples. PCR-RFLP analysis showed three banding pattern corresponding to the peculiar pattern of A. pegreffii. Sequence data from ribosomal ITS and mitochondrial COI were analysed by Neighbour Joining, Minimum Evolution and Maximum Parsimony methods to evaluate the phylogenetic relationships among A. simplex sensu lato. The phylogenetic trees obtained for both ITS and COI revealed the existence of three distinct clades for A. simplex sensu sricto, A. simplex C and A. pegreffii and the sequences obtained in this study clearly clustered together with A. pegreffii sequences present in the database.

Histopathological observations of anisakid nematode specimens detected on the liver surface of M. merluccius are illustrated. Encapsulated specimens of the L3 stage of the nematode were similar in size and morphometry to those found into the peritoneal cavity. Anisakis larvae encapsulated on the liver surface within dense and pearl coloured envelops caused host hepatic tissue necrosis, large cavities and oedematous liver spots to the host.

Open access
Parasitism and pathogenicity of curly-leaf parsley with the root-knot nematode Meloidogyne javanica in Southern Italy

Summary

Severe infections of parsley plants and soil infestations with Meloidogyne javanica during an autumn surveys for the pathogenic root-knot nematode infestations were found in Monopoli at Bari province in Southern Italy. This unusual severe infection of parsley, considered a winter crop, was possibly instigated by a very warm autumn from the previous year. Nematodes were extracted from soil samples according to the Coolen’s method. Morphological analysis (based on stylet length, tail length and shape, adult females perineal pattern, excretory pore position and Ep/stylet ratio) and molecular studies were used for the nematode characterization and identification. In the soil of infested area a severely deformed root systems were observed, showing a galling rate = 2.5 - 4 (scale 0-5) and a soil nematode population densities ranging from 350 to 2,730 eggs and J2 per 5 g of fresh root. M. javanica attack on parsley roots is a limiting factor for plant growth. Considering that curly-leaf parsley varieties resistant to the nematodes are not yet available control strategies must be focused on reduction of soil infestation level below tolerance limit of the target nematode species. Due to the higher cost and reduced availability of fumigant and non-fumigant nematicides, soil solarization, organic amendments or biological control approaches should be preferably used as alternatives.

Open access