Reference values of parathyroid hormone and vitamin D Hormone by chemiluminescent automated assay / Valores de referencia de hormona paratiroidea y vitamina D por método quimioluminiscente automatizado en perros

Objective. Provide reference data for parathyroid hormone 1-84 (PTH 1-84) and 25OH Vitamin D (25OH D) using a new technique. Materials and methods. The hormones were evaluated, in serum, using a third generation automated chemiluminescent method for PTH in a group of 60 adult dogs, clinically healthy, grouped according to age in years in GA: 1 to 5, GB: 6 to 10 and GC:>10. Results. Data expressed as average ± DS were for PTH (pg/ml): 9.3±2.3; 12±6.3; 12.2±3.7; and for 25OH D (ng/ml): 84.2±27.8; 68.2±16.0; 63.6±23.1, respectively. The PTH value was significantly greater (p<0.05) in groups B and C in comparison with A, but no significant differences were observed between GB and GC. The 25OH D concentration was significantly less in GB (p<0.05) and in GC (p<0.01) in comparison with GA, showing no differences between GB and GC. A negative correlation between 25OH D and PTH was found (r= -0.28; p=0.015). Conclusions. Data contributed by this study provide reference values for PTH 1-84 and 25OH D, evaluated using a third generation automated chemiluminescent method for PTH in local dogs. The results will facilitate monitoring diseases that alter the metabolism of calcium and phosphorus in dogs.

Objetivo. Aportar datos de referencia, para hormona paratiroidea 1-84 (PTH 1-84) y 25OH Vitamina D (25OH D) con una nueva técnica. Materiales y métodos. Las hormonas fueron valoradas, en suero, por un método quimioluminiscente automatizado, y de tercera generación para la PTH, en una población de 60 perros adultos clínicamente sanos, agrupados según edad en años en GA: 1 a 5, GB: 6 a 10 y GC:>10. Resultados. Los datos expresados como media ± DS fueron para la PTH (pg/ml): 9.3±2.3; 12±6.3; 12.2±3.7; y para la 25OH D (ng/ml): 84.2±27.8; 68.2±16.0; 63.6±23.1, respectivamente. El valor de PTH fue significativamente mayor (p<0.05) en los grupos B y C con respecto al A, pero no se observó diferencia significativa entre GB y GC. La concentración de 25OH D fue significativamente menor en el GB (p<0.05) y en el GC (p<0.01) con respecto al GA, sin haber diferencias entre los GB y GC. Se encontró una correlación negativa entre 25OH D y PTH (r= -0.28; p=0.015). Conclusiones. Los datos aportados en este trabajo permiten disponer de valores de referencia de PTH 1-84 y de 25OH D, valorados por un método quimioluminiscente automatizado y de tercera generación para la PTH, en una población local de perros. Los resultados facilitarán el seguimiento de enfermedades que alteran el metabolismo del calcio y fósforo en perros.

Aislamiento de Streptomyces ssp: productores de antibióticos de suelos de Magallanes, XII Región de Chile / Isolation of Streptomyces: producing antibiotics from soils of Magallanes, XII Region of Chile

Muchas cepas de Actinomycetes sintetizan compuestos biodinámicos que se aprovechan como antimicrobianos o sustancias líticas o degradativas de moléculas resistentes, por lo cual se los ha pesquisado en los suelos más diversos del mundo y sobre todo en zonas aún no perturbadas por la acción del humano. Los suelos chilenos y en especial los de la XII (Magallanes) presentan características únicas, por factores climaticos y de aislamiento y tienen una diversidad característica. En esta investigación se estudiaron muestras de suelos de siete estaciones continentales de la XII Región. De 65 muestras de suelos obtenidas, 73.8 por ciento resultaron positivas, aislándose 86 cepas de Streptomyces. Se ensayó la actividad antibiótica mediante la técnica de discos KÅster y Williams y se encontró que el 59.3 por ciento presentaron actividad para algunas de las cepas de referencia, observándose una mayor frecuencia inhibitoria sobre Staphylococcus areus y Bacillus subtilis simultáneamente. Se realizó la extracción de los productos activos mediante solventes de distinta polaridad. Los extractos de n-hexano y cloroformo resultaron ser los más activos.

Efecto antibiótico de cepas silvestres de Streptomyces aisladas de suelos chilenos / Antimicrobial effect of wild Streptomyces strains isolated from chilean soils

Background: the solts of the southern part of Chile, that are isolated, cold, humid, poorly axygenated and with a low acitity, could contain new strains of antimicrobial producing Streptomyces strains with antimicrobial activity towards pathogenic bacteria and fungi. Material and methods: two hundred fifty eight soil and sediment samples were collected from 148 paces in Souther regions of Chile. They were cultured in Kuster-Williams growth media and the presence of Streptomyces was confirmed by microscopic examination and biochemical characterization. The antimicrobial activity against reference microorganisms. Results: Seventy seven percent of soils were positive and 542 wild strains of Streptomyces were isolates; of these, 266 had antimicrobial activity. Fifty three percent of isolates had activity against S aureus 43 percent against B subtilis and 0.7 percent against E coli. Most Streptomyces were active against more than one organism. When there was activity against single organisms, these were mostly eucariotic, such as C albicans and T mentagrophytes. Among clinical microorganisms, 29 percent of S aureus strains were inhibited, while P aeruginosa, Alternaria sp, P vulgaris and Y enterocolitica strains were not inhibited. The most frequent Streptomyces morphotypes were those showing pigmented colonies with flexuous and spiral shaped chains of arthopores. Conclusions: soils of the southern region Chile allow the grouth of abundant native strains of Streptomyces with a promising anticrobial activity

Bacteriocinogenia, un sistema de antagonismo bacteriano / Bacteriocinogenia, a system for bacterial antagonism

Bacterial antagonism depends on many factors. Among others, for example we have competition for an essential nutrient, the production of toxic metabolites or the release of antibiotic substances. The production of bacteriocines by "killer" strains correspons to the latrer, being determined by plasmidial or chromosomal genes. On the other hand, the susceptibility to a given bacteriocine depends on the presence of surface recptors that are codified by the cellular DNA. The bacteriocine particles correspond to protein conglomerates which are sometimes associated with glucolipids. With the death of the productive cell, these particles are livated motivated by synthesis. The similarities which they share with the bacteriophage are many. However, their fundamental differences are that they lack nuclic acid and their incapcity to transmit themselves. Cellular death caused by the action of the bacteriocine is extremely quck, acting on the permeability of the plasmatic membrane, on the macromolecular syntesis (DNA, RNA an proteins) and on cellular oxidation. The wide range of bacteriocine and their respective spectre of action over the more or less related strains are excellent parameters to detect, identify and classify the productive bacteria and the susceptible ones. With only a few exceptions, the bacteriocines not lethal to their own productive cell nor to taxonomically distant species. This has led to intersting ecological and epidemiological outlooks. The amplitude of this phenomenon in Gram+ and Gram- bacteria has led to the study of fine mechanisms which have triggered the genetic expression to elaborate bacteriocines, determining the one responsible for this are the genes and localized signals in transmissible episomes or in chromosomal operons

Espectro bactericida de piocinas sobre cepas colectadas en hospitales de las regiones IX y X de Chile / Bactericidal effects of pyocins upon strains isolated in different hospitals of the IX and X region, Chile

The inhibitory effect of 5 pyocins produced by wildstrains of Ps aeruginosa was tested by qualitative and quantitative techniques. 313 strains of 4 species: E coli, P vulgaris, Ps aeruginosa and St aureus were assayed. It was shown that the most active pyocin was P37, which inhibited 276 out of 313 strains tested. About 80% of E. coli and 90% os St aureus strain were inhibited by the pyocins uner being tested. It was established that sensitivity to pyocin was not restricted to close-related species but extends to unrelated families also