[Methylene blue test for the determination of viability of free larvae of Trichinella spiralis]. / Coloración de azul de metileno como alternativa para determinar la viabilidad de larvas libres de Trichinella spiralis.

The present research was carried out with the purpose of determining whether or not the methylene blue test could also evidence viability of free larvae of Trichinella spiralis, taking into account its usefulness in the determination of viability of protoscolices in Echinococcus granulosus. To this end, three T. spiralis larval suspensions (M1, M2 and M3) were used, each containing 500 free larval stages. A hundred microl of methylene blue solution 1:10000 in distilled water were added to 100 microl of the larval suspension. Larvae were observed under optical microscopy to evaluate motility. M1 was exposed to -30 degrees C and could be observed on day 70, M2 was exposed to 80 degrees C during 5 minutes and it was immediately observed under optical microscopy, and M3 was maintained at 4 degrees C during the experiment as a 100% viability testing. Our results indicated that when T. spiralis larvae took up 100% of the methylene blue stain (M1 and M2), their inner structures appeared not only retracted but also stained blue, whereas in the M3 suspension test, larvae remained unstained and 100% of them showed their typical spiral-like movement.

[Acanthamoeba sp. keratitis: first case confirmed by isolation and molecular typification in Bahía Blanca, Buenos Aires Province, Argentina]. / Queratitis por Acanthamoeba sp.: primer caso confirmado por aislamiento y tipificación molecular en Bahía Blanca, provincia de Buenos Aires, Argentina.

Some species of the Acanthamoeba genus cause keratitis, a very painful, most likely unilateral corneal infection , associated with eye and vision impairment. We here present a case of a 31-year-old female patient, a regular user of soft contact lenses without good practices of lens hygiene and handling. The patient attended medical consultation after two months of inflammation and pain in her right eye. After ophthalmological studies, and due to suspicion of a parasitic infection, a biopsy was performed and the sample submitted for bacteriological and parasitological analyses. Moreover, contact lens holders and lens cleaning solutions were studied. The samples yielded negative results for bacterial infection. However, cultivation of all samples showed the presence of amoeboid parasites. Isolated amoebae were morphologically and molecularly classified as members of the Acanthamoeba genus. This is the first case of keratitis caused by Acanthamoeba in Bahía Blanca, Buenos Aires Province, where the parasite was identified by specific and sensitive molecular techniques.

Un caso de Dipylidum caninum en humano. / A case of dipylidum caninim in human

Es bien conocido que las helmintiasis son de caracter cosmopolita, algunas de ellas comunes al hombre como consecuencia de condiciones antihigienicas de vida o malos habitos alimenticios. Algunos son patrimonio casi exclusivo del hombre asi como otros lo son de determinados vertebrados, los que por razones inmunologicas na properan en especies alejadas o afines. No obstante existen parasitos que siendo casi exclusivos de una determinada especie pueden circunstancialmente desarrollar su ciclo biologico en el hombre. Tal es el caso de Dipylidium caninum