Abstract

ZERPA LARRAURI, Rito; ESPINOZA BLANCO, Yrma  and  HUIZA FRANCO, Alina Floralia. In vitro antiparasite susceptibility test for Blastocystis hominis, Entamoeba histolytica-E. dispar, Balantidium coli. An. Fac. med. [online]. 2012, vol.73, n.1, pp.47-49. ISSN 1025-5583.

Background: In vitro antiparasite susceptibility test for Blastocystis hominis, Entamoeba histolytica-E. dispar y Balantidium coli, as well as intestinal protozoaria cultures, have rarely been reported in the medical literature. In vitro susceptibility tests for those parasites have not been published locally. Objectives: To determine an alternative in vitro antiparasite susceptibility test and its resistance to antimicrobials. Design: Prospective, descriptive study. Settings: Instituto de Medicina Tropical "Daniel Alcides Carrion", Universidad Nacional Mayor de San Marcos, and Instituto Especializado de Salud del Niño, Lima, Peru. Biologic material: Blastocystis hominis, Entamoeba histolytica-E. dispar and Balantidium coli cultures against five antimicrobials. Methods: Sixty-four Blastocystis hominis, 16 Entamoeba histolytica-E. dispar and 16 Balantidium coli cultures were used against five antimicrobials: metronidazole, cotrimoxazole, tetracycline, furazolidone and ciprofloxacin. B. hominis, E. histolytica-E. dispar strains were cultured in modified Pavlova’s media, from 500 feces samples of children with intestinal parasitosis diagnosis, and B. coli from pig feces. In vitro susceptibility tests were done by microculture methods in modified Pavlova’s media, in 200 uL media little pools without antiparasites (control) and with antiparasites in 10 concentrations going from 128 ug/mL through 0,25 ug/mL; after incubation at 36º C for 48 hours, direct microscope exam reading compared development in control media and pools containing antimicrobials. Main outcome measures: Minimum inhibiting concentration (MIC). Results: For B. hominis with metronidazole CIM 90 was 64 ug/mL and CIM 50: 2 ug/mL; for E. histolytica-E. dispar with metronidazole, CIM 90: 1 ug/mL and CIM 50: 0.5 ug/mL; for B. coli with tetracicline, CIM 90: 0.25 ug/mL and CIM 50: 0.25 ug/mL. Conclusions: This preliminar information to be validated showed strains behavior of mentioned parasites, and represents a potential alternative use (in case of validation) in treatment of studied protozoa, as well as in resistance surveillance.

Keywords : Antiparasitary susceptibility test; minimum inhibiting concentration; protozoa.

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