Murine Experimental Root Canal Infection: Cytokine Expression in Response to F. nucleatum and E. faecalis

Abstract The aim of this study was to evaluate the gene expression of proinflammatory (RANKL, TNF-a and IFN-g) and regulatory (TGF-b and IL-10) cytokines as reaction to experimental infection by mono or bi-association of Fusobacterium nucleatum (ATCC 10953) and Enterococcus faecalis (ATCC 19433). F. nucleatum and E. faecalis, either in mono- or bi-association were inoculated into the root canal system (RCS) of Balb/c mice. Animals were sacrificed at 10 and 20 days after infection and periapical tissues surrounding the root were collected. The mRNA expression of the cytokines RANKL, TNF-a, IFN- g, TGF-b and IL-10 was assessed using real-time PCR. The Kruskal-Wallis test was used for statistical analysis. F. nucleatum mono-infection induced high expression of RANKL and TNF-a, while its modulation was due to IL-10. High expression of IFN-g at day 20 was up-regulated by E. faecalis and RANKL; TNF-a was up-regulated by an independent mechanism via IL-10 and TGF-b. Bi-association (F. nucleatum and E. faecalis) stimulated high expression of RANKL, TNF-a and IFN-g, which seemed to be modulated by TGF-b 20 days later. The gene expression of proinflammatory cytokines was more prominent in the earlier periods of the experimental periapical infection, which concomitantly decreased in the later period. This expression may be regulated by IL-10 and TGF-b in an infection-specific condition

Resumo O objetivo deste trabalho foi avaliar a expressão gênica de citocinas pró-inflamatórias (RANKL, TNF-a e IFN-g) e regulatórias (TGF-b e IL-10) em resposta à infecção experimental por Fusobacterium nucleatum (ATCC 10953) e Enterococcus faecalis (ATCC 19433) como mono-infecção ou em bi-associação. F. nucleatum e E. faecalis foram inoculados no sistema de canais radiculares de camundongos Balb/c, tanto isoladas como em bi-associação. Os animais foram sacrificados em 10 e 20 dias após a infecção, e os tecidos periapicais foram coletados. As expressões do mRNA das citocinas RANKL, TNF-a, IFN-g, TGF-b e IL-10 foram analisadas por meio do real-time PCR. O teste de Kruskal-Wallis foi utilizado para análise estatística. A mono-infecção com F. nucleatum induziu alta expressão de RANKL e TNF-a, enquanto sua modulação ocorreu devido à IL-10. A alta expressão de IFN-g no dia 20 foi regulada positivamente por E. faecalis e RANKL; TNF-a foi regulada positivamente por um mecanismo independente via IL-10 e TGF-b. A bi-associação (F. nucleatum e E. faecalis) estimulou uma alta expressão de RANKL, TNF-a e IFN-g, que parece ser modulada por TGF-b após 20 dias. A expressão gênica de citocinas pró-inflamatórias foi mais proeminente nos estágios iniciais da infecção periapical experimental, com concomitante redução no período tardio. Este fenômeno pode ser regulado por IL-10 e TGF-b em uma condição de infecção específica.

Plant Growth Promotion and Root Colonization by EPS Producing Enterobacter sp. RZS5 under Heavy Metal Contaminated Soil.

The heavy metal resistant bacterium isolated from field soil and identified as Enterobacter sp. RZS5 tolerates a high concentration (100-2000 mM) of various heavy metal ions such as Mn2+, Ni2+, Zn2+, Cu2+, CO2+ and Fe2+ when grown in such environment and produces exopolysaccharides (EPS). Here, we have demonstrated EPS production by Enterobacter sp. RZS5 during 60 h of growth in yeast extract mannitol broth (YEMB). The yield increased by two fold after the addition of 60 M of Ca2+; 50 M of Fe2+ and 60 M of Mg2+ ions in YEMB, and the optimization of physico-chemical parameters. EPS was extracted with 30% (v/v) of isopropanol as against the commonly used 50% (v/v) isopropanol method. EPS-rich broth promoted seed germination, shoot height, root length, number of leaves and chlorophyll content of wheat (Triticum aestivum) and peanut (Arachis hypogaea) seeds. The higher colony-forming unit of Enterobacter sp. in soil inoculated with EPS rich broth of Enterobacter sp. indicated the root colonizing potential and rhizosphere competence of the isolate. The FTIR spectra of the EPS extract confirmed the presence of the functional group characteristics of EPS known to exhibit a high binding affinity towards certain metal ions. This overall growth and vigour in plants along with the effective root colonization, reflected the potential of the isolate as an efficient bio-inoculant in bioremediation.

Optimization of biodegradable plastic production on sugar cane molasses in Enterobacter sp. SEL2

Contaminated environments have a large number of bacteria which can accumulate PHA as their energy reserves. Out of 54 isolated bacterial strains from three groups of contaminated sites 48 were found PHA positive. The sites were grouped on the basis of the type of carbon sources i.e. sugars, fatty acids and much diverse type. Strains MFD5, MFD11, UML3, USL2, SEL2, SEL3, SEL10 and PFW1 produced 69.9 ± 0.29, 75.27 ± 0.45, 65.43 ± 0.1, 72.54 ± 0.27, 76.61 ± 0.28, 61.81 ± 0.05, 71.16 ± 0.09 and 74.92 ± 0.5 percent of PHA to their constant cell weight (CCW) respectively in PHA detection media supplemented with 2% glucose. Molasses, whey, crumbs hydrolysate and palm oil were checked as inexpensive carbon sources. Molasses alone could supply the required nutrients for growth and PHA production. Strain SEL2 produced 47.36 ± 0.45% PHA using 2% molasses at 37 °C and pH 7.0. Upon production optimization the best accumulation (80.95 ± 0.01%) was observed in PHA detection media with 0.2% nitrogen source, 3% molasses, pH 5.0 and 37 °C by the strain SEL2. The overall effect of the presence of increased molasses concentration in the media was positive it increased the accumulation period till 72 h. Enterobacter sp. SEL2 (JF901810) is first time being reported for PHA production.

Characterization of an exopolysaccharide produced by a marine Enterobacter cloacae.

An exopolysaccharide producing marine bacterium, Enterobacter cloacae, was isolated from marine sediment collected from Gujarat coast, India. Chemical investigation of exopolysaccharide (EPS 71 a) revealed that this exopolysaccharide was an acidic polysaccliaride containing high amount of uronic acid, fucose and sulfate which is rare for bacterial exopolysaccharides. EPS 71a was found to have fucose, galactose, glucose and glucuronic acid in a molar ratio of 2: 1: 1: 1.

Estudo da estabilidade térmica de suspensöes orais de cefalexina / Study of thermal stability of oral suspensions of cephalexin

A cefalexina é um antibiótico cefalosporânico de primeira geração sintetizado no final da década de setenta e utilizado principalmente no tratamento de infecções do sistema respiratório, causadas por microrganismos Gram positivos. Devido a sua estabilidade em meio ácido, as preparações farmacêuticas contendo cefalexina apresentam excelente absorção por via oral, sendo disponibilizadas no comércio na forma de comprimidos, cápsulas e suspensões orais. Apesar do amplo emprego deste antibiótico existem poucos dados na literatura a respeito da estabilidade da cefalexina em preparações farmacêuticas. Particularmente, em relação às suspensões orais, o estudo de estabilidade torna-se mais difícil devido à complexidade da formulação e às inúmeras interções que podem ocorrer entre o fármaco e os excipientes utilizados...