Carmen Mascaró

Acute intestinal anisakiasis in Spain: a fourth-stage Anisakis simplex larva

A case of acute intestinal anisakiasis has been reported; a nematode larva being found in the submucosa of the ileum of a woman in Jaén (Spain). The source of infection was the ingestion of raw Engraulis encrasicholus. On the basis of its morphology, the worm has been identified as a fourth-stage larva of Anisakis simplex. In Spain, this is the ninth report of human anisakiasis and also probably the first case of anisakiasis caused by a fourth-stage larva of A. simplex.

Isolation, in vitro culture, ultrastructure study, and characterization by lectin-agglutination tests of Phytomonas isolated from tomatoes (Lycopersicon esculentum) and cherimoyas (Anona cherimolia) in southeastern Spain

Plants ofLycopersicon esculentum (grown in greenhouses) andAnona cherimolia cultivated in southeastern Spain were examined for the presence of trypanosomatid flagellates. Kinetoplastid protozoa were found in the fruits but not in the phloem or other plant tissues. Parasites were detected from the onset of fruiting. Isolates were adapted to in vitro culturing in monophase media. The form and the structural organization was studied by scanning and transmission electron microscopy. The parasites showed an ultrastructural pattern similar to that of other species of the genusPhytomonas. In tomatoes experimentally inoculated with flagellates cultivated in vitro, we observed that the parasites did not lose their infectious capacity. Three strains of trypanosomatids of the genusPhytomonas, isolated from different species ofEuphorbia (E. characias andE. hyssopifolia) and fromCocos nucifera, were compared with our isolates by lectinagglutination tests. Our isolates were different from the two strains isolated fromEuphorbia, but with this technique we could not differentiate our isolates from those of the coconut, nor could we differentiate between the isolates, their ultrastructural similarity together with their similar behavior in the lectin-agglutination test suggesting that these isolates have a common origin.

Respiratory cryptosporidiosis in a bovine.

Intestinal cryptosporidiosis has been extensively studied in young calves, but respiratory invasion by Cryptosporidium in these animals has, surprisingly, not been investigated. In the present study the parasite was observed in lung tissue of a calf, using light and electron microscopy. This demonstrates that Cryptosporidium can develop in the bronchial epithelium in bovines.

Ultrastructural study of Crytosporidium development in Madin-Darby canine kidney cells

Transmission electron microscope studies have been made into phases of the life cycle of a bovine isolate of Cryptosporidium cultured in vitro on Madin-Darby canine kidney cells. The cytoplasm of parasitized cells was noticeably altered, including marked vacuolization and the appearance of membrane structures close to the developing parasites. These changes suggest that the protozoan may release cytopathogenic factors.

In vitro culture of Glugea sp.

Recently the low host specificity of some microsporidians has been demonstrated and it has been indicated that many of these micro-organisms could be transmitted from invertebrates to mammals and adapt to changes in temperature. In this work, we demonstrate the first successful in vitro culture of a fish microsporidia of the genus Glugea on larval cells of the mosquito Aedes albopictus at 28 degrees C, and we show ultrastructural aspects of the different life cycle stages. It was impossible on salmon cells CHSE-214 at 21 degrees C. This study will be valuable for further work in biochemistry and immunology in addition to chemotherapy for microsporidiosis humans and animals.

Antigen incorporation on Cryptosporidium parvum oocyst walls

Cryptosporidium parvum oocysts are the infective stages responsible for transmission and survival of the organism in the environment. In the present work we show that the oocyst wall, far from being a static structure, is able to incorporate antigens by a mechanism involving vesicle fusion with the wall, and the incorporation of the antigen to the outer oocyst wall. Using immunoelectron microscopy we show that the antigen recognized by a monoclonal antibody used for diagnosis of cryptosporidiosis (Merifluor(R), Meridian Diagnostic Inc.) could be found associated with vesicles in the space between the sporozoites and the oocysts wall, and incorporated to the outer oocyst wall by an unknown mechanism.

Human gnathostomosis in Spain: first report in humans.

Gnathostomosis has been known since 1836, when the parasite was discovered in the stomach of a tiger in London Zoo. Today it is considered an important food-borne parasitic zoonosis, endemic mainly in Asian countries where some people prefer to eat raw fish, amphibians or reptiles. In its mammal definitive host the adults are located in the stomach wall, even in granulomes. The eggs leave the definitive host with the faeces and develop further in an aquatic environment. Larva 1, mobile, is ingested by a copepod, in which it evolves to immature larva 3. The larvae become infectious for mammals in a second intermediary non-specific host, which ingest the copepod. These may be a number of crustaceans, cold-blooded vertebrates, birds or mammals. The infective larva can pass from one host to another within different food chains of the biotope in question. Maturation to the adult stages takes place only in the definitive specific hosts (canids and felids in G. spinigerum). It is a slow process of some 6.5 months in duration. This is due to a migration followed by the infectious larval stage, which involves: perforation of the gastric wall, entry into the liver, migration to muscles and connective tissues, and, again, perforation of the gastric wall from the outside in order to reach its final destination. This internal migration often leads to ectopic locations, especially in uncommon hosts, such as humans, where Gnathostoma larvae are not able to reach sexual maturity. The most dangerous locations are the brain and spinal cord, while others include the eye, lung, pleura, urinary tract and intestine (Oriel and Ash, 1994). In some patients with eosinophilic myeloencephalitis, G. spinigerum has been found in the eyes, suggesting a possible migration via the optic nerve. External gnathostomosis usually comes from the therapeutic application of reptile or amphibian flesh or the manipulation of raw meat. Most human cases, both external (cutaneous migration) and internal (visceral migration), have been diagnosed in Thailand and Japan, or in * Corresponding author. Present address: Departamento de Parasitologia, Facultad de Ciencias, Universidad de Granada, E-18071, Granada, Spain. Tel.: +34-58-243263; fax: +34-58243174. E-mail address: cmascaro@goliat.ugr.es (C. Mascaro).

The Different Behavior of Diphtheria Toxin, Modeccin and Ricin in HeLa Cells Infected with Trypanosoma cruzi

ABSTRACT. We have studied the action of diphtheria toxin, modeccin and ricin on HeLa cells infected by Trypanosoma cruzi. Parasitized HeLa cells were resistant to diphtheria toxin and modeccin, whereas non‐parasitized cells from the same cultures and control cultures showed cytopathological alterations. Protein synthesis, assayed by the incorporation of labelled methionine, diminished in toxin‐treated control cultures but remained unaltered in the infected ones, compared to synthesis by untreated infected cells. Ricin, on the other hand, is a toxin that enters the cytoplasm by endocytosis. It has greater cytopathological effects in parasitized cells than in non‐parasitized ones from the same cultures or uninfected control cells. Protein synthesis was inhibited in infected cultures treated with ricin.

Ultrastructural Details of Cryptosporidium parvum Development in Calf Intestine

Cryptosporidium parvum and C. muris appear to be different species found in calves, with different oocysts size and distribution on the gastrointestinal tract. This work presents new images of C. parvum ultrastructure in calf intestine, mainly its development in nonmicrovillous cells and the presence of microtubular structures in the membrane enveloping the macrogamonts and immature oocysts.

The effects of IFN-γ activated mouse peritoneal and alveolar macrophages on Cryptosporidium parvum development

Mouse peritoneal and alveolar macrophages were interacted in vitro with C. parvum oocysts and cultured in normal medium and in medium with IFN-gamma. The results showed that in vitro activation of macrophages by IFN-gamma limits C. parvum development although the inhibitory effect is not as potent as in other intracellular parasitic protozoa.