Differential Cleaving of Specific Substrates for Cathepsin-Like Activity Shows Cysteine and Serine Protease Activities and a Differential Profile Between and , Sibling Species Major Etiologic Agents of Anisakiasis.

Humans can contract anisakiasis by eating fish or squid containing live larvae of the third stage (L3) of the parasitic nematodes of the genus , majorly from and , sibling species of the complex. Most cases diagnosed molecularly are due to , although has also been identified in human cases. Cathepsins are mostly lysosomal multifunctional cysteine proteases and can participate in the pathogenicity of parasites.

Differential proteolytic activity in Anisakis simplex s.s. and Anisakis pegreffii, two sibling species from the complex Anisakis simplex s.l., major etiological agents of anisakiasis.

Proteolytic activity was studied in two sibling species of Anisakis (Nematoda: Anisakidae), A. simplex s.s.

Fishing area and fish size as risk factors of Anisakis infection in sardines (Sardina pilchardus) from Iberian waters, southwestern Europe.

The sardine (Sardina pilchardus) is a fish commonly consumed and appreciated in many countries, although they are more likely to be eaten fresh in western Mediterranean countries such as Spain, Portugal, France or Italy. A molecular epidemiological survey of sardines from 5 fishing areas of the Spanish Mediterranean (Málaga, southern Spain) and Atlantic coasts (southern: Cádiz and Isla Cristina; northern: A Coruña and Ondarroa) was carried out to determine the presence of Anisakis spp. larvae.

Anthelminthic activity of the cyclotides (kalata B1 and B2) against schistosome parasites.

The risk of reduced sensitivity of the human schistosomes to praziquantel has led to efforts to find new therapies. Here, the cyclotides kalata B1 (kB1), kalata B2 (kB2), MCoCC-1, and MCoTI-II, cyclic peptides extracted from plants and shown to be potent against nematodes and insects, were tested for antischistosome activity. In vitro assays showed that high concentrations (500-1000 μg/mL) of either kB1 or kB2 killed Schistosoma japonicum and Schistosoma mansoni adults within 5 min, whereas MCoTI-II and MCoCC-1 had no effect.

Proteolytic activity in Hysterothylacium aduncum (Nematoda: Anisakidae), a fish gastrointestinal parasite of worldwide distribution.

Proteases have a significant role in the life cycle of parasites and the pathogen-host relationship, being regarded as important virulence factors. In the parasitic nematode Hysterothylacium aduncum proteolytic activity was measured during in vitro development from third larval stage (L3) to mature adult, using DQ red casein as a fluorogenic substrate. Proteolytic activity was detected in all the developmental stages studied and at all pH values within the range employed (2.

Collagenolytic activity related to metalloproteases (and serine proteases) in the fish parasite Hysterothylacium aduncum (Nematoda: Anisakidae).

Proteases play a vital role in both the life cycle of parasites and the parasite-host relationship and are considered important virulence factors. In the present study, the presence of proteases with collagenolytic activity was investigated in the fish nematode Hysterothylacium aduncum during in vitro development. Collagenolytic activity was found in all studied developmental stages of the nematode (third [L3] and fourth [L4] larval stages and adults).

Cathepsin B- and L-like cysteine protease activities during the in vitro development of Hysterothylacium aduncum (Nematoda: Anisakidae), a worldwide fish parasite.

Proteinases play an important role as virulence factors both in the life-cycle of parasites and in the pathogen-host relationship. Hysterothylacium aduncum is a worldwide fish parasite nematode which has been associated with non-invasive anisakidosis and allergic responses to fish consumption in humans. Cysteine proteinases have been associated with allergy to plant pollens, detergents and dust mites.

CO2-fixing enzymes and phosphoenolpyruvate metabolism in the fish parasite Hysterothylacium aduncum (Ascaridoidea, Anisakidae).

CO2 stimulates the development of many of the intestinal helminths that are able to fix CO2 by means of phosphoenolpyruvate carboxykinase (PEPCK), such as Hysterothylacium aduncum. We determined the activity of CO2-fixing enzymes such as PEPCK and phosphoenolpyruvate carboxylase (PEPC), although no significant activity was detected for pyruvate carboxylase or carboxylating-malic enzyme. The former act on phosphoenolpyruvate (PEP) to yield oxalacetate.

Anisakis simplex: CO(2)-fixing enzymes and development throughout the in vitro cultivation from third larval stage to adult.

We studied the effect of CO(2) on the in vitro cultivation of Anisakis simplex, an aquatic parasitic nematode of cetaceans (final hosts) and fish, squid, crustaceans and other invertebrates (intermediate/paratenic hosts), and, occasionally, of man (accidental host). The results showed that a high pCO(2), at a suitable temperature, is vital for the optimum development of these nematodes, at least from the third larval stage (L3) to adult. After 30 days cultivation in air, molting to L4 (fourth larval stage) was reduced to 1/3, while survival was about 1/3 of that when cultivated in air + 5% CO(2).

CO(2)-fixing enzymes during moulting from third larval to fourth larval stage of Anisakis simplex and Hysterothylacium aduncum (Nematoda: Anisakidae).

The fixing of CO(2) is an important metabolic process for many organisms. In the anisakid nematodes, CO(2) has been shown to be necessary for their development, at least in vitro. The presence of CO(2) stimulates the moulting (M3) of the larvae from the third (L3) to the fourth (L4) stage and prolongs the survival, at least, in vitro.