Chromosomal studies in species of Salvia (Lamiaceae) from Argentina

Meiotic and mitotic chromosomes of 13 species of Salvia from Argentina were studied. Most of our data are new counts but some, mainly from cultivated species, confirm previous reports or represent numbers which are different from those cited previously. Only Salvia gilliesii Benth. and the introduced species S. coccinea Juss., S. farinacea Benth., S. involucrata Cav. and S. microphylla Kunth are diploids. S. cardiophylla Benth., S. procurrens Benth., S. splendens Roem. & Schult. and S. uliginosa Benth. are tetraploids; S. stachydifolia Benth. is hexaploid; and S. guaranitica A. St.-Hil., S. pallida Benth. and S. rypara Briq. are octoploids. The basic number most frequently found is x = 11, but two species, S. procurrens and S. uliginosa, have x = 13. S. farinacea has x = 10 but this species is a widespread cultivated plant, not native in this area. Seven of the studied species showed one to three B chromosomes. We discuss some systematic and evolutionary aspects of the genus in the light of the cytogenetic data, the relationships between geographical distribution and chromosome numbers in relation to levels of ploidy and basic chromosome numbers, and make comparisons with some of the different taxonomic sections.Facultad de Ciencias Naturales y Muse

Relationships in Patagonian species of Berberis (Berberidaceae) based on the characterization of rDNA internal transcribed spacer sequences

Sequence analysis of the internal transcribed spacer (ITS) of the 18S(ITS1)-5.8S 26S(ITS2) rDNA region was performed in order to analyse the phylogenetic relationships between 13 Patagonian species of the genus Berberis (Berberidaceae). The divergence values between the pairwise sequence in the studied Patagonian species were in the range 2.9–22.9%. The lengths of the ITS1 and ITS2 sequences were in the range 227–231 bp and 220–224 bp, respectively, and the 5.8S sequence was 159 bp throughout all species. B. microphylla sensu Landrum does not appear to be monophyletic based on current sampling. Indeed, we suggest that B. microphylla should be distinguished from B. buxifolia, B. parodii, and B. heterophylla . ITS sequences, together with data obtained from morphological, biochemical, amplified fragment length polymorphism, and cytological characterizations, support the existence of diploid and polyploid hybrid speciation in the genus.Fil: Bottini, Maria Cecilia Juana. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Austral de Chile; ChileFil: de Bustos, A.. Universidad de Alcalá; EspañaFil: Sanso, Andrea Mariel. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Jouve, N.. Universidad de Alcalá; EspañaFil: Poggio, Lidia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias; Argentin

Genetic characterization of Shiga toxin-producing Escherichia coli O26:H11 strains isolated from animal, food, and clinical samples

The Shiga-toxin producing Escherichia coli (STEC) may cause serious illness in human. Here we analyze O26:H11 strains known to be among the most reported STEC strains causing human infections. Genetic characterization of strains isolated from animal, food, and clinical specimens in Argentina showed that most carried either stx1a or stx2a subtypes. Interestingly, stx2a-positive O26:H11 rarely isolated from cattle in other countries showed to be an important proportion of O26:H11 strains circulating in cattle and food in our region. Seventeen percent of the isolates harbored more than one gene associated with antimicrobial resistance. In addition to stx, all strains contained the virulence genes eae-β, tir, efa, iha, espB, cif, espA, espF, espJ, nleA, nleB, nleC, and iss; and all except one contained ehxA, espP, and cba genes. On the other hand, toxB and espI genes were exclusively observed in stx2-positive isolates, whereas katP was only found in stx1a-positive isolates. Our results show that O26:H11 STEC strains circulating in Argentina, including those isolated from humans, cattle, and meat products, present a high pathogenic potential, and evidence that cattle can be a reservoir of O26:H11 strains harboring stx2a.Fil: Krüger, Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil. Centro de Investigacion Veterinaria de Tandil; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Lucchesi, Paula Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil. Centro de Investigacion Veterinaria de Tandil; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Sanso, Andrea Mariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil. Centro de Investigacion Veterinaria de Tandil; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Etcheverría, Analía Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil. Centro de Investigacion Veterinaria de Tandil; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Bustamante, Ana Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil. Centro de Investigacion Veterinaria de Tandil; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Burgán, Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil. Centro de Investigacion Veterinaria de Tandil; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Fernandez, Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil. Centro de Investigacion Veterinaria de Tandil; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Fernandez, Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil. Centro de Investigacion Veterinaria de Tandil; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Leotta, Gerardo Anibal. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto de Genética Veterinaria "Ingeniero Fernando Noel Dulout"; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Friedrich, Alexander W.. University of Groningen; Países BajosFil: Padola, Nora L.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil. Centro de Investigacion Veterinaria de Tandil; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Rossen, John W. A.. University of Groningen; Países Bajo

Genetic characterization of Shiga toxin-producing Escherichia coli O26:H11 strains isolated from animal, food, and clinical samples

The Shiga-toxin producing Escherichia coli (STEC) may cause serious illness in human. Here we analyze O26:H11 strains known to be among the most reported STEC strains causing human infections. Genetic characterization of strains isolated from animal, food, and clinical specimens in Argentina showed that most carried either stx1a or stx2a subtypes. Interestingly, stx2a-positive O26:H11 rarely isolated from cattle in other countries showed to be an important proportion of O26:H11 strains circulating in cattle and food in our region. Seventeen percent of the isolates harbored more than one gene associated with antimicrobial resistance. In addition to stx, all strains contained the virulence genes eae-β, tir, efa, iha, espB, cif, espA, espF, espJ, nleA, nleB, nleC, and iss; and all except one contained ehxA, espP, and cba genes. On the other hand, toxB and espI genes were exclusively observed in stx2-positive isolates, whereas katP was only found in stx1a-positive isolates. Our results show that O26:H11 STEC strains circulating in Argentina, including those isolated from humans, cattle, and meat products, present a high pathogenic potential, and evidence that cattle can be a reservoir of O26:H11 strains harboring stx2a.Instituto de Genética Veterinari

Especies de Viola (Violaceae) adventicias en Argentina

Se revisan materiales de entidades adventicias de Viola en Argentina y se comprueba la presencia de 4 especies diferentes: V. arvensis, V. metajaponica, V. odorata y V. tricolor. V. metajaponica es lectotipificada y se discute la identidad de V. japonica. Las especies son descriptas e ilustradas, y se provee una clave diacrítica, además de datos de ecología y distribución geográfica