title: Variability in infection efficiency in vitro of different strains of the microsporidian Encephalitozoon hellem.
abstract: The infection efficiency of different strains of Encephalitozoon hellem of human origin was tested in Vero E6 cell cultures, scoring the number of infection foci (NIF) after 9, 14, 20, and 24 days of inoculation. The results revealed a strong interaction of the strain type with time: different strains showed different proliferative dynamics. Number of infection foci was lower on the first sampling day for CDC: V257, EHVS-96, and PV6-96, with a subsequent increase at a higher rate for the first strain and lower for the latter. In contrast, PV7-96 showed the highest NIF at the first sampling, followed by a slight decrease. Since these strains were selected by their genotype for the polar tube protein (PTP)-1A, 1B, 1C, and 2C, respectively, it is tempting to suggest a major role of this protein in the differences detected, although the influence of other genes that hypothetically may also differ among the strains employed cannot be discarded. The different in vitro infection efficiencies raise the possibility that some strains of E. hellem will also produce more aggressive features in infected patients.
authors.affiliation: Laboratorio de Genética, Universidad San Pablo-CEU, Urbanización Montepríncipe, 28668 Boadilla del Monte, Madrid, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Haro
authors.forename: Carmen
authors.initials: C
authors.lastname: Aguila
authors.forename: Soledad
authors.initials: S
authors.lastname: Fenoy
authors.forename: Nuno
authors.initials: N
authors.lastname: Henriques-Gil
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000235:genetics; D002460:Cell Line; D002522:Chlorocebus aethiops; D016819:Encephalitozoon / Q000145:classification* / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology; D005656:Fungal Proteins; D005838:Genotype; D006801:Humans; D015800:Protozoan Proteins / Q000235:genetics; D013172:Spores, Fungal / Q000502:physiology; D014709:Vero Cells
chemical_list: D002352:Carrier Proteins; D005656:Fungal Proteins; D015800:Protozoan Proteins; C482683:polar tube protein 1, Encephalitozoon hellem