Salmonellosis remains a major problematic food born zoonosis worldwide. Poultry and poultry products have been frequently incriminated as the major sources for the aetiological agent, Salmonella species. The implement...Salmonellosis remains a major problematic food born zoonosis worldwide. Poultry and poultry products have been frequently incriminated as the major sources for the aetiological agent, Salmonella species. The implementation of appropriate surveillance and monitoring programme for food safety ultimately requires the examination of food for the presence of food borne pathogens. This study was aimed at evaluating the effectiveness of Modified Semisolid Rappaport-Vassiliadis (MSRV) and Muller-Kauffmann tetrathionate-novobiocin (MKTTn) selective enrichment media for the isolation of Salmonella, as well as assessment of the performance of xylose-lysine-deoxycholate (XLD) agar as the classical and preferential selective plating medium by comparing it with Brilliant Green (BG) agar for the detection of Salmonella in the primary production of poultry based on the ISO 6579:2002. Three hundred and seventy-four (374) samples from the primary poultry production system underwent the traditional culture method for the detection of Salmonella involving pre-enrichment, selective enrichment, selective plating and confirmation. The rate of recovery of Salmonella from the entire samples was 59.1%. The rate of recovery of Salmonella from XLD and BG selective plating media when MSRV selective enrichment media was used was 98.2% and 95.5% respectively whereas 90.0% and 64.3% respectively when MKTTn selective enrichment media was used. The highest sensitivity was observed in the combination of MSRV/XLD (0.98), followed by MSRV/BG (0.95). The combination of MSRV/BG had the highest specificity (0.88) followed by MKTTn/BG (0.65). Based on the results of this study, selective enrichment media play a substantial role on the sensitivity and specificity of the selective plating media. MSRV was revealed as the most important selective enrichment medium, necessary for the investigation of Salmonella and that its combination with BG selective plating media yielded the best result for the selective isolation of Salmonella in the primary production of poultry.展开更多
A new fluorescent probe （BPbl） for Pb^2＋ has been synthesized, where diethanolamine （receptor） is linked with 4,4-difluoro-4- bora-3a, 4a-diaza-s-indacene （BODIPY） （fluorophore） via a methylene group （spacer...A new fluorescent probe （BPbl） for Pb^2＋ has been synthesized, where diethanolamine （receptor） is linked with 4,4-difluoro-4- bora-3a, 4a-diaza-s-indacene （BODIPY） （fluorophore） via a methylene group （spacer）. The absorption （496 nm） and emission （505 nm） wavelengths are in visible range. The fluorescence quantum yields of the lead-free and lead-bound states of BPb1 in acetonitrile are 0.013 and 0.693, respectively. The large chelation enhanced fluorescence effect （CHEF） with Pb^2＋ can be explained by the blocking of the photoinduced electron transfer （PET） process.展开更多
文摘Salmonellosis remains a major problematic food born zoonosis worldwide. Poultry and poultry products have been frequently incriminated as the major sources for the aetiological agent, Salmonella species. The implementation of appropriate surveillance and monitoring programme for food safety ultimately requires the examination of food for the presence of food borne pathogens. This study was aimed at evaluating the effectiveness of Modified Semisolid Rappaport-Vassiliadis (MSRV) and Muller-Kauffmann tetrathionate-novobiocin (MKTTn) selective enrichment media for the isolation of Salmonella, as well as assessment of the performance of xylose-lysine-deoxycholate (XLD) agar as the classical and preferential selective plating medium by comparing it with Brilliant Green (BG) agar for the detection of Salmonella in the primary production of poultry based on the ISO 6579:2002. Three hundred and seventy-four (374) samples from the primary poultry production system underwent the traditional culture method for the detection of Salmonella involving pre-enrichment, selective enrichment, selective plating and confirmation. The rate of recovery of Salmonella from the entire samples was 59.1%. The rate of recovery of Salmonella from XLD and BG selective plating media when MSRV selective enrichment media was used was 98.2% and 95.5% respectively whereas 90.0% and 64.3% respectively when MKTTn selective enrichment media was used. The highest sensitivity was observed in the combination of MSRV/XLD (0.98), followed by MSRV/BG (0.95). The combination of MSRV/BG had the highest specificity (0.88) followed by MKTTn/BG (0.65). Based on the results of this study, selective enrichment media play a substantial role on the sensitivity and specificity of the selective plating media. MSRV was revealed as the most important selective enrichment medium, necessary for the investigation of Salmonella and that its combination with BG selective plating media yielded the best result for the selective isolation of Salmonella in the primary production of poultry.
基金support by Shanxi Scholarship Council of China(No.200310)
文摘A new fluorescent probe （BPbl） for Pb^2＋ has been synthesized, where diethanolamine （receptor） is linked with 4,4-difluoro-4- bora-3a, 4a-diaza-s-indacene （BODIPY） （fluorophore） via a methylene group （spacer）. The absorption （496 nm） and emission （505 nm） wavelengths are in visible range. The fluorescence quantum yields of the lead-free and lead-bound states of BPb1 in acetonitrile are 0.013 and 0.693, respectively. The large chelation enhanced fluorescence effect （CHEF） with Pb^2＋ can be explained by the blocking of the photoinduced electron transfer （PET） process.
