Use of a multiplex PCR system for the simultaneous detection of heat labile toxin I and heat stable toxin II Escherichia coli cells in environmental waters near Taichung City

The enterotoxins produced by enterotoxigenic Escherichia coli (ETEC) cells include heat labile (LT) and heat stable toxins (ST), These toxins cause diarrheal in humans and domestic animals. In this study, we combined LT I and ST II gene specific PCR primers into a multiplex PCR system and used this system for the simultaneous detection of LT I and ST II ETEC cells in tap water and environmental waters. Using Chromocult coliform agar (CCA), we found that tap water and underground water were contaminated with 0-10(0) CFU / ml of E. coli and coliform cells while the waters from four rivers near Taichung City were contaminated with 10(2)-10(4) CFU / ml of E. coli and coliform cells. Furthermore, three of the four river waters were contaminated with LT I / ST II and ST II ETEC cells. The high levels of microfloral contamination in these river waters near an urban area should be attended to urgently

Pulsed field gel electrophoresis (PFGE) analysis for multidrug resistant Salmonella enterica serovar Schwarzengrund isolates collected in six years (2000-2005) from retail chicken meat in Taiwan

Salmonella Schwarzengrund is one of the causative agents of human salmonellosis and animal infections. High prevalence of multidrug resistant strains of S. Schwarzengrund from chicken meat has been recently reported in Taiwan. With an attempt to see if such prevalence in chicken meat was due to the recirculation of S. Schwarzengrund strains in traditional marketplaces, a total of 173 S. Schwarzengrund strains isolated between 2000 and 2005 from 417 retail chicken meat samples purchased from Taipei, Taiwan were analyzed using pulsed field gel electrophoresis (PFGE) method. For XbaI and AvrII digested DNA, a total of 23 and 16 PFGE patterns, respectively, were obtained. When these patterns were combined, a total of 47 subtypes were obtained and the major subtypes were X3A2, X1A2 and X2A1. Since it was found that these major subtypes were repeatedly found for multidrug resistant strains collected from 2000 to 2005, we then collected the chicken meat isolates from central and southern Taiwan in 2006. These strains did not show similar major subtypes as those found in Taipei. Such results might also suggest that the repeated appearance of some major subtypes for S. Schwarzengrund strains isolated each year in Taipei was due to the recirculation of these strains in retail marketplace during these years. (C) 2010 Elsevier Ltd. All rights reserved

Comparison of the pulsed field gel electrophoresis patterns and virulence profiles of the multidrug resistant strains of Salmonella enterica serovar Schwarzengrund isolated from chicken meat and humans in Taiwan

Salmonella Schwarzengrund is one of the frequent serovars isolated from chicken meat in Taiwan. This organism is also one of the invasive Salmonella serovars which may cause human salmonellosis and animal infections. In this study, a total of 466 strains of S. Schwarzengrund including 232 retail chicken meat isolates and 234 human isolates in Taiwan were analyzed for their antibiotic resistance and pulsed field gel electrophoresis (PFGE) patterns. For XbaI-digested DNA, a total of 110 PFGE patterns were obtained. When patterns from both origins were analyzed, of these patterns, 21 were shared by isolates from chicken meat samples and humans. In these 21 patterns, 153 (32.8%) isolates from both origins shared the top five patterns. Since ACSSXTT R-type strains are the major concern worldwide and they accounted for 74.5% of total strains used in this study, such R-type strains in the top five XbaI-digested patterns were then further analyzed with AvrII digestion followed by PFGE and PCR assay targeted to 10 Salmonella virulence genes, i.e., avrA, ssaQ, mgtC, siiD, sopB, gipA, sodC1, sopE1, spvC, and bcfC. When PFGE patterns and virulence gene profiles were combined for the analysis of ACSSXTT R-type strains of S. Schwarzengrund, 29 strains from both origins showed the same pattern combinations. Such results suggested the possible transmission of S. Schwarzengrund from chicken meat to humans. (C) 2011 Elsevier Ltd. All rights reserved

Contamination of Salmonella Schwarzengrund cells in chicken meat from traditional marketplaces in Taiwan and comparison of their antibiograms with those of the human isolates

Salmonella Schwarzengrund is one of the infective Salmonella serotypes for humans and food animals, such as poultry and swine. Because consumption of foods containing salmonellae due to cross contamination or inadequate cooking may lead to human salmonellosis, in this report, the prevalence of Salmonella Schwarzengrund contamination in chicken meat samples purchased from different traditional marketplaces in Taiwan between 2000 and 2006 was investigated. In addition, 228 Salmonella Schwarzengrund strains isolated from these chicken meat samples and 30 human isolates obtained between 2004 and 2006 were compared for their antimicrobial susceptibility. Results showed that the prevalence of Salmonella Schwarzengrund contamination in raw chicken meat samples was 30.5%. Of all of the Salmonella isolates from chicken meat, Salmonella Schwarzengrund accounted for 39.3%. On the other hand, of the total Salmonella strains isolates from humans between 2004 and 2006, Salmonella Schwarzengrund accounted for 2.8%. All these chicken meat isolates and human isolates were multidrug-resistant and demonstrated high resistance to ampicillin, gentamicin, kanamycin, streptomycin, tetracycline, nalidixic acid, trimethoprim-sulfamethoxazole, and chloramphenicol. For gentamicin and kanamycin, however, the resistance gradually declined. The antibiogram study may indicate the abuse of some antibiotics for both humans and chickens. Also, transmission of Salmonella Schwarzengrund strains between humans and food of animal origin is possible

Efeito do armazenamento sobre as propriedades tecnológicas da farinha, de variedades de trigo cultivadas no Brasil Effect of storage on technological properties of wheat flour of Brazilian grown wheats

<abstract language="eng">The aim of this work was to evaluate changes in technological properties of newly milled flours of BR-23, BR-35 and Anahuac varieties (Brazilian grown wheat) during storage for 180 days. Quality of samples was analysed for their rheological properties, acidity, falling number, glutomatic test and baking test, after periods of 0, 7, 15, 30, 60, 90, 120, 150 and 180 days. Most evident changes were the increase in flour acitidy and dough elasticity. The other characteristics did not show expressive changes. The flour of Anahuac variety was less influenced by the storage than the other ones. The results showed an increment in the flour quality, during 60-90 days of storage, althoug the baking test did not show expressive changes during all the period of storage

Anti-tumor Immunity of Gene Vaccine with Nucleofection Technology

OBJECTIVE To observe enhancement of anti-tumor immunity by gene vaccine using nucleofection technology.METHODS The technique of nucleofection was used to transfereffectively plasmid DNA into immature dendritic cells (iDCs); we studied immune responses regulated by DNA vaccine using real-time quantitative polymerase chain reaction (PCR) and Western-blotting to optimize the follow-up lymphocyte activation. The anti-tumor capacity of lymphocytes primed by DCs was analyzed using lactate dehydrogenase with a non-radioactive cytotoxicity assay.RESULTS Human monocyte-derived dendritic cells (hMoDCs) were induced by interleukin (IL)-4 and granulocyte-macrophage colony-stimulating factor (GM-CSF) in vitro from human monocytes for 5 or 6 days. DNA vaccine was transfected to iDCs with high transfection (35.73%) using nucleofection. Compared with the iDC group, the expression of Th1 cell cytokine IL-12, IL-18 and Th2 cell cytokine IL-4 increased after stimulation. CD86 and CD83 were upregulated compared with non-nucleofected groups 48 hours after nucleofection with DC-pVAX-PRA. The result of the cytotoxicity assay showed that DCs-pVAX-PRA primed non-adherent peripheral blood mononuclear cells (PBMCs) exhibit their highest cytotoxicity against target cells.CONCLUSION The results show that DNA vaccine was transfected to iDC with high transfection efficiency using nucleofection, priming autologous lymphocytes for anti-tumor immunity by upregulated expression of co-stimulatory molecules, adhesion molecules and cytokines. These results provided a basis to explore the molecular mechanism of DNA vaccine in vivo