Anisakis Nematodes in Fish and Shellfish- from infection to allergies.

Anisakidosis is a zoonotic parasitosis induced by members of the family Anisakidae. The anisakid genera includes Anisakis, Pseudoterranova, Hysterothylacium and Contracaecum. The final definitive hosts of these nematodes are marine mammals with a complex life cycle. These nematode parasites use different crustaceans and fish species as intermediate or paratenic hosts and humans are accidental hosts. Human anisakiasis, the infections caused by members of the genus Anisakis, occurs, when seafoods, particularly fish, contaminated with the infective stage (third stage larvae [L3]) of this parasite, are consumed. Pseudoterranovosis, on the other hand is induced by members of the genus Pseudoterranova. These two genera of anisakids have been implicated in human disease globally. There is a rise in reports of gastro-intestinal infections accompanied by allergic reactions caused by Anisakis simplex and Anisakis pegreffii. This review provides an update on current knowledge on Anisakis as a food-borne parasite with special focus on the increasingly reported diversity of fish and crustacean hosts, allergens and immunological cross-reactivity with invertebrate proteins rendering this parasite a significant public health issue.

Molecular and immunological characterisation of tropomyosin from Anisakis pegreffii.

Tropomyosin (TM) is a major allergen in shellfish, known to cross-react with mite, cockroach and/or some roundworm (nematode) TM. In this study, we aimed to express and purify TM from the parasitic nematode Anisakis pegreffii and also to characterise its cross-reactivity with TM from shellfish. A. pegreffii was isolated from the flathead tiger fish (Neoplatycephalus richardsoni) and characterised using single-strand conformation polymorphism (SSCP)-based sequencing of the first and second internal transcribed spacers (ITS-1 and ITS-2) of nuclear ribosomal DNA. The recombinant tropomyosin (rTM) of A. pegreffii was expressed, purified and confirmed by immunohistochemistry, sequencing and LC-MS/MS analyses. Immunohistochemistry showed the muscle and the base layer of the third-stage larvae (L3) of A. pegreffii as the location of TM in A. pegreffii. The molecular relationship of TM of A. pegreffii with homologs from other nematodes and crustaceans was inferred from phylogenetic analysis. Immunogenicity of TM from A. pegreffii was tested by immunoblotting, which showed that rTM from A. pegreffii binds to IgE from sera of patients with allergy to crustaceans. Immunoblotting also showed that the anti-TM monoclonal antibody (MAb) did not recognise rTM from A. pegreffii. The rTM from A. pegreffii was, however, recognised by anti-TM polyclonal antibodies (PAbs) as well as anti-crustacean polyclonal antibodies (PAbs). The detection of specific serum IgE antibody against parasite TM has been proposed as a useful approach for the diagnosis of parasite-induced allergy. The findings of this study merit further exploration of the cross-reactive allergenic proteins of Anisakis for improved, future diagnosis of allergenic diseases.

In vitro antimicrobial activity of crude extracts from plants Bryophyllum pinnatum and Kalanchoe crenata.

Extracts from the leaves of Bryophyllum pinnatum and Kalanchoe crenata were screened for their antimicrobial activities. Solvents used included water, methanol, and local solvents such as palmwine, local gin (Seaman's Schnapps 40% alcoholic drink,) and "omi ekan-ogi" (Sour water from 3 days fermented milled maize). Leaves were dried and powdered before being soaked in solvents for 3 days. Another traditional method of extraction by squeezing raw juice from the leaves was also employed. All extracts were lyophilized. These extracts were tested against some gram-negative organisms (Escherichia coli ATCC 25922, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Shigella flexneri, Salmonella paratyphi, Citrobacter spp); gram-positive organisms Staphylococcus aureus ATCC 25213, Staphylococcus aureus, Enterococcus faecalis, Bacillus subtilis) and a fungus (Candida albicans). Agar well diffusion and broth dilution methods were used to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) at concentrations of 512 mg/ml to 4 mg/ml. All the organisms except Candida albicans were susceptible to the extracts obtained from the traditional method. The squeezed-leaf juice of Kalanchoe crenata was the most active one with MIC of 8 mg/ml against Pseudomonas aeruginosa, Klebsiella pneumoniae and Bacillus subtilis, 32 mg/ml against Shigella flexneri, 64 mg/ml against Escherichia coli and 128 mg/ml against the control strain Staphylococcus aureus while its MBC is 256 mg/ml against these organisms except Bacillus subtilis and Klebsiella pneumoniae. The gram-positive organisms were more sensitive to the methanol and local gin-extract of Bryophyllum pinnatum. Extracts from other solvents showed moderate to weak activity.

Medicinal plants useful for malaria therapy in Okeigbo, Ondo State, Southwest Nigeria.

There is increasing resistance of malaria parasites to chloroquine, the cheapest and commonly used drug for malaria in Nigeria. Artemisin, a product from medicinal plant indigenous to China, based on active principle of Artemisia annua, has been introduced into the Nigerian market. However not much has been done to project antimalaria properties of indigenous medicinal plants. This study thus, has the main objective of presenting medicinal plants used for malaria therapy in Okeigbo, Ondo State, South west Nigeria. Focus group discussions and interview were held about plants often found useful for malaria therapy in the community. Fifty species (local names) including for example: Morinda lucida (Oruwo), Enantia chlorantha (Awopa), Alstonia boonei (Ahun), Azadirachta indica (Dongoyaro) and Khaya grandifoliola (Oganwo) plants were found to be in use for malaria therapy at Okeigbo, Southwest, Nigeria . The parts of plants used could either be the barks, roots, leaves or whole plants. The recipes also, could be a combination of various species of plants or plant parts. This study highlights potential sources for the development of new antimalarial drugs from indigenous medicinal plants found in Okeigbo, Nigeria.