[Objective] This study aimed to establish a method for quantitative detection of mRNA transcriptional level of SS2 adhesive related-factors of Streptococcus suis serotype 2 （SS2） by fluorescent quantitative PCR. []V...[Objective] This study aimed to establish a method for quantitative detection of mRNA transcriptional level of SS2 adhesive related-factors of Streptococcus suis serotype 2 （SS2） by fluorescent quantitative PCR. []Vlethod] The gene fragments en- coding SS2 adhesive related-factors MRP, FBPS and CPS2J and a housekeeping gene aroA were amplified by reverse transcription PCR from the total RNA of SS2, cloned, and sequenced. The recombinant plasmids containing the target genes were constructed, and used as templates in Real-time PCR. [Result] Dynamic curves, stan- dard curves and melting curves of the adhesive related-factors and aroA were ob- tained by the optimized Real-time PCR system. The standard curves showed a good linear relationship between template copy number and circulation number, and the correlation coefficients （FF） of the standard curves were over 0.995. Also, these as- says were highly specific a^d there was single specific melting peak for every gene. Moreover, the assays were highly sensitive and had a detection limit of 1.0×102 copies in 1 μl of initial templates. Finally, it was highly repeatable and had a coeffi- cient of variation less than 2% for intra-assay. [Conclusion] This study will provide a way to reveal the adhesion mechanism of SS2 to different host cells at molecular level.展开更多
In a high concentration substrate medium, a heterotrophic bacterium with high removal efficiency of ammonium, named W1, was isolated from activated sludge of coking wastewater treatment facility. The bacterium was Gra...In a high concentration substrate medium, a heterotrophic bacterium with high removal efficiency of ammonium, named W1, was isolated from activated sludge of coking wastewater treatment facility. The bacterium was Gram-negative, rod-shaped, and identified preliminarily as Alcaligenes sp. according to its morphological and physiological properties and its 16S rRNA gene sequence analysis. In the high concentration ammonium medium (400 mg·L 1 4 NH -N), the effects of C source, N source, C/N ratio and initial pH of medium on ammonium removal were investigated in order to determine the optimal condition for strain W1. The maximum ammonium removal was around 95% in 4 days in an improved medium. The production of N 2 gas was examined in a closed system that was full of pure oxygen at the beginning. N 2 gas was detected in the system after 4 days of cultivation, which further testified that strain W1 has heterotrophic nitrification and aerobic denitrification abilities simultaneously.展开更多
[ Objective] To establish a Taqman real-time PCR for detection of Salmonella in pet food. [Method] A pair of primers and a probe were designed based on published nucleotide sequence of invA gene encoding the invasion ...[ Objective] To establish a Taqman real-time PCR for detection of Salmonella in pet food. [Method] A pair of primers and a probe were designed based on published nucleotide sequence of invA gene encoding the invasion protein of Salmonella enterica. [ Result] The assay detects Salmonella specifically. The detection limit of the real-time PCR was 17 CFU/test （25 uL/test） for the positive strain. This method was effective to detect artificially contaminated pet food. [ Conclusion] The results showed that Taqman PCR assay was rapid and accurate for detection of Salmonella from infected pet food.展开更多
The knowledge on rabbit welfare may be improved by the use of correct tools for monitoring the different aspects of rabbit industrial farming. Therefore, the aim of this study was to define parameters related to healt...The knowledge on rabbit welfare may be improved by the use of correct tools for monitoring the different aspects of rabbit industrial farming. Therefore, the aim of this study was to define parameters related to health and welfare of animals in industrial farms with intensive husbandry. Health, management, environmental and productive parameters were firstly characterized and then a protocol to assess welfare of rabbits was define. The research was conducted on 8 industrial farms from 2004 to 2007 and around 30 inspections were done in each farm. At each visit, the health conditions were established by： （1） necropsy on animals of different productive category; （2） specific laboratory investigations based on the lesions observed; （3） checking the presence of parasites in environmental faecal samples; （4） bacteriological examination of vaginal, nasal and rectal swabs of rabbit of different age. The immune conditions and the efficacy of vaccinations were measured by determining anti-Myxomatosis and anti-Rabbit Haemorrhagic Disease antibodies using competitive ELISAs, and anti-Encephalitozoon cunicoli antibodies by immunocarbonassay. The environmental conditions were evaluated by measuring air temperature, relative humidity, ammonia concentration and bacterial/fungal count. Finally the productive parameters were also recorded and elaborated. All the entered values were then utilized for defining a score system to establish health and welfare conditions.展开更多
Phage contamination is a very serious and unavoidable problem in modem fermentation industry. It is necessary to develop sensitive and rapid phage detection methods for the early detection of phage contamination. In t...Phage contamination is a very serious and unavoidable problem in modem fermentation industry. It is necessary to develop sensitive and rapid phage detection methods for the early detection of phage contamination. In the present work, a real-time, rapid, specific and quantitative phage T4 detection method based on surface plasmon resonance （SPR） technique has been in- troduced. Escherichia coli was immobilized onto the preformed MPA self-assembled monolayer （SAM） through the widely used EDC/NHS cross-linking reaction as the recognition element. The bacteria immobilization was verified efficiently through the electrochemical measurements and fluorescence microscopy observations. The specific adsorption was much stronger than the non-specific adsorption of phage T4 binding to the biosensor surface modified by E. coli, and the latter could be neglected. The detection sensitivity reached 1×10^7 PFU/mL within 10 min. Within the experimental phage concentrations, the linear cor- relation between the SPR response and the phage concentration was good. The results suggest that the SPR technique is a po- tentially powerful tool for the phage or other virus detections, as a label-free, real-time, and rapid method.展开更多
基金Supported by National Natural Science Foundation of China(31072155)Natural Science Foundation of Jiangsu Province(BK2010068)+1 种基金Fund for Independent Innovation of Agricultural Science in Jiangsu Province[CX(11)2060]Special Fund for Agroscientific Research in the Public Interest(201303041)~~
文摘[Objective] This study aimed to establish a method for quantitative detection of mRNA transcriptional level of SS2 adhesive related-factors of Streptococcus suis serotype 2 （SS2） by fluorescent quantitative PCR. []Vlethod] The gene fragments en- coding SS2 adhesive related-factors MRP, FBPS and CPS2J and a housekeeping gene aroA were amplified by reverse transcription PCR from the total RNA of SS2, cloned, and sequenced. The recombinant plasmids containing the target genes were constructed, and used as templates in Real-time PCR. [Result] Dynamic curves, stan- dard curves and melting curves of the adhesive related-factors and aroA were ob- tained by the optimized Real-time PCR system. The standard curves showed a good linear relationship between template copy number and circulation number, and the correlation coefficients （FF） of the standard curves were over 0.995. Also, these as- says were highly specific a^d there was single specific melting peak for every gene. Moreover, the assays were highly sensitive and had a detection limit of 1.0×102 copies in 1 μl of initial templates. Finally, it was highly repeatable and had a coeffi- cient of variation less than 2% for intra-assay. [Conclusion] This study will provide a way to reveal the adhesion mechanism of SS2 to different host cells at molecular level.
基金Supported by the National Natural Science Foundation of China (51078252)the International Cooperation Projects of Shanxi Province (2010081018)the Natural Science Foundation of Shanxi Province (2010011016-1)
文摘In a high concentration substrate medium, a heterotrophic bacterium with high removal efficiency of ammonium, named W1, was isolated from activated sludge of coking wastewater treatment facility. The bacterium was Gram-negative, rod-shaped, and identified preliminarily as Alcaligenes sp. according to its morphological and physiological properties and its 16S rRNA gene sequence analysis. In the high concentration ammonium medium (400 mg·L 1 4 NH -N), the effects of C source, N source, C/N ratio and initial pH of medium on ammonium removal were investigated in order to determine the optimal condition for strain W1. The maximum ammonium removal was around 95% in 4 days in an improved medium. The production of N 2 gas was examined in a closed system that was full of pure oxygen at the beginning. N 2 gas was detected in the system after 4 days of cultivation, which further testified that strain W1 has heterotrophic nitrification and aerobic denitrification abilities simultaneously.
基金Supported by the Project of General Administration of Quality Supervision,Inspection and Quarantine of the People's Republic of China( 201110034)
文摘[ Objective] To establish a Taqman real-time PCR for detection of Salmonella in pet food. [Method] A pair of primers and a probe were designed based on published nucleotide sequence of invA gene encoding the invasion protein of Salmonella enterica. [ Result] The assay detects Salmonella specifically. The detection limit of the real-time PCR was 17 CFU/test （25 uL/test） for the positive strain. This method was effective to detect artificially contaminated pet food. [ Conclusion] The results showed that Taqman PCR assay was rapid and accurate for detection of Salmonella from infected pet food.
文摘The knowledge on rabbit welfare may be improved by the use of correct tools for monitoring the different aspects of rabbit industrial farming. Therefore, the aim of this study was to define parameters related to health and welfare of animals in industrial farms with intensive husbandry. Health, management, environmental and productive parameters were firstly characterized and then a protocol to assess welfare of rabbits was define. The research was conducted on 8 industrial farms from 2004 to 2007 and around 30 inspections were done in each farm. At each visit, the health conditions were established by： （1） necropsy on animals of different productive category; （2） specific laboratory investigations based on the lesions observed; （3） checking the presence of parasites in environmental faecal samples; （4） bacteriological examination of vaginal, nasal and rectal swabs of rabbit of different age. The immune conditions and the efficacy of vaccinations were measured by determining anti-Myxomatosis and anti-Rabbit Haemorrhagic Disease antibodies using competitive ELISAs, and anti-Encephalitozoon cunicoli antibodies by immunocarbonassay. The environmental conditions were evaluated by measuring air temperature, relative humidity, ammonia concentration and bacterial/fungal count. Finally the productive parameters were also recorded and elaborated. All the entered values were then utilized for defining a score system to establish health and welfare conditions.
基金support from the National Basic Research Program of China (2011CB933600)the National Natural Science Foundation of China (21077081,20921062)+1 种基金the Natural Science Foundation of Hubei Province (2010CDB01302)the Fundamental Research Funds for Central Universities (1103005 and 1101007)
文摘Phage contamination is a very serious and unavoidable problem in modem fermentation industry. It is necessary to develop sensitive and rapid phage detection methods for the early detection of phage contamination. In the present work, a real-time, rapid, specific and quantitative phage T4 detection method based on surface plasmon resonance （SPR） technique has been in- troduced. Escherichia coli was immobilized onto the preformed MPA self-assembled monolayer （SAM） through the widely used EDC/NHS cross-linking reaction as the recognition element. The bacteria immobilization was verified efficiently through the electrochemical measurements and fluorescence microscopy observations. The specific adsorption was much stronger than the non-specific adsorption of phage T4 binding to the biosensor surface modified by E. coli, and the latter could be neglected. The detection sensitivity reached 1×10^7 PFU/mL within 10 min. Within the experimental phage concentrations, the linear cor- relation between the SPR response and the phage concentration was good. The results suggest that the SPR technique is a po- tentially powerful tool for the phage or other virus detections, as a label-free, real-time, and rapid method.
