Cryptosporidiosis is an important zoonosis caused by the Cryptosporidium species. To develop a PCR diagnostic kit for molecular detection and differential diagnosis of Cryptosporidium spp., a portion of ITS-1 sequence...Cryptosporidiosis is an important zoonosis caused by the Cryptosporidium species. To develop a PCR diagnostic kit for molecular detection and differential diagnosis of Cryptosporidium spp., a portion of ITS-1 sequence of Cryptosporidium. andersoni was chosen as the target DNA for designing the species-specific primers （ZRQF/ZR）. The kit components were determined after the PCR amplification conditions were serially optimized. A series of tests were conducted in the specificity, sensitivity, stability, reproducibility, and stored period of the kit, respectively. The results showed that only C. andersoni were amplified specific band of about 500 bp, while Cryptosporidium. parvum, Cryptosporidium. baileyi, Eimeria sp of dairy cow, Toxoplasma gondii, Eimeria sp of pig, Ascaris suum, Cyclospora sp, and E. coli could not be amplified. 254 oocysts of C. andersoni was the lowest number that could be detected using the kit. The kit worked well after being stored at room temperature, 4 and -20℃ for nine months. Fecal specimens, which were collected from a total of 243 calves on four different dairy farms in Guangdong Province, China, and one dairy farm in Henan Province, China, were examined using the kit; the positive rate of the kit was 2-13% higher than that of the routine methods. The results indicated that the kit can detect fecal samples faster, more sensitively, and conveniently, and can provide a useful tool for the identification and differentiation of C. andersoni from the other Cryptosporidium species; it also has implications for further studies on molecular epidemiology and differential diagnostics of cryptosporidiosis in animals.展开更多
[Objectives]To fully understand the quality of commercial enzyme inhibition-colorimetric pesticide residue rapid detection kits,so that they can play a greater role in the detection and supervision of agricultural pro...[Objectives]To fully understand the quality of commercial enzyme inhibition-colorimetric pesticide residue rapid detection kits,so that they can play a greater role in the detection and supervision of agricultural products.[Methods]The sensitivity of 28 kinds of pesticides was determined by using the commercially available enzyme inhibition colorimetric rapid detection kit with Hendu brand.[Results]There was a significant difference in the sensitivity of the kit to each pesticide,and the kit was more sensitive to dichlorvos among the 28 pesticides tested.The sensitivity to methyl isosalifos,dimethoate,isocarbophos,fenthion and phorate was poor,and the sensitivity to quinalphos was different between 3.0 and 2.5 mL.[Conclusions]The large difference of the sensitivity of the enzyme inhibition-colorimetric rapid detection kit for pesticide residues to different kits is a reason for the false positive and false negative test results of the kit,which needs to be considered by relevant personnel.展开更多
A cDNA fragment of about 860 bp corresponding to the c33-c gene in the non-structural region 3 (NS3) of HCV genome was obtained from one plasma derived from a Chinese HCV carrier who came from Tai’an of Shandong Prov...A cDNA fragment of about 860 bp corresponding to the c33-c gene in the non-structural region 3 (NS3) of HCV genome was obtained from one plasma derived from a Chinese HCV carrier who came from Tai’an of Shandong Province, China by the application of reverse transcription (RT) and polymerase chain reaction (PCR) techniques. After the sequence of the cDNA fragment was determined and compared with the equivalent region of. the HCV-I (HCV-US) and HCV-II (HCV-BK) genomes, the nucleotide/ amino acid sequence homologies were found to be 79. 2%/91. 3% and 91. 3%/93. 9%, respectively. The prokaryotic expression vector pBV220 was employed for the overproduction of c33-c native recombinant protein in E. coli cells. The expression products were detected by enzyme-linked immunosorbent assay (ELISA) and Western blotting with antisera of chronic hepatitis C patients, and a molecular weight 31 kD of c33-c viral protein was shown to account for 14% of the total cellular soluble proteins. This product was extracted展开更多
文摘Cryptosporidiosis is an important zoonosis caused by the Cryptosporidium species. To develop a PCR diagnostic kit for molecular detection and differential diagnosis of Cryptosporidium spp., a portion of ITS-1 sequence of Cryptosporidium. andersoni was chosen as the target DNA for designing the species-specific primers （ZRQF/ZR）. The kit components were determined after the PCR amplification conditions were serially optimized. A series of tests were conducted in the specificity, sensitivity, stability, reproducibility, and stored period of the kit, respectively. The results showed that only C. andersoni were amplified specific band of about 500 bp, while Cryptosporidium. parvum, Cryptosporidium. baileyi, Eimeria sp of dairy cow, Toxoplasma gondii, Eimeria sp of pig, Ascaris suum, Cyclospora sp, and E. coli could not be amplified. 254 oocysts of C. andersoni was the lowest number that could be detected using the kit. The kit worked well after being stored at room temperature, 4 and -20℃ for nine months. Fecal specimens, which were collected from a total of 243 calves on four different dairy farms in Guangdong Province, China, and one dairy farm in Henan Province, China, were examined using the kit; the positive rate of the kit was 2-13% higher than that of the routine methods. The results indicated that the kit can detect fecal samples faster, more sensitively, and conveniently, and can provide a useful tool for the identification and differentiation of C. andersoni from the other Cryptosporidium species; it also has implications for further studies on molecular epidemiology and differential diagnostics of cryptosporidiosis in animals.
文摘[Objectives]To fully understand the quality of commercial enzyme inhibition-colorimetric pesticide residue rapid detection kits,so that they can play a greater role in the detection and supervision of agricultural products.[Methods]The sensitivity of 28 kinds of pesticides was determined by using the commercially available enzyme inhibition colorimetric rapid detection kit with Hendu brand.[Results]There was a significant difference in the sensitivity of the kit to each pesticide,and the kit was more sensitive to dichlorvos among the 28 pesticides tested.The sensitivity to methyl isosalifos,dimethoate,isocarbophos,fenthion and phorate was poor,and the sensitivity to quinalphos was different between 3.0 and 2.5 mL.[Conclusions]The large difference of the sensitivity of the enzyme inhibition-colorimetric rapid detection kit for pesticide residues to different kits is a reason for the false positive and false negative test results of the kit,which needs to be considered by relevant personnel.
文摘A cDNA fragment of about 860 bp corresponding to the c33-c gene in the non-structural region 3 (NS3) of HCV genome was obtained from one plasma derived from a Chinese HCV carrier who came from Tai’an of Shandong Province, China by the application of reverse transcription (RT) and polymerase chain reaction (PCR) techniques. After the sequence of the cDNA fragment was determined and compared with the equivalent region of. the HCV-I (HCV-US) and HCV-II (HCV-BK) genomes, the nucleotide/ amino acid sequence homologies were found to be 79. 2%/91. 3% and 91. 3%/93. 9%, respectively. The prokaryotic expression vector pBV220 was employed for the overproduction of c33-c native recombinant protein in E. coli cells. The expression products were detected by enzyme-linked immunosorbent assay (ELISA) and Western blotting with antisera of chronic hepatitis C patients, and a molecular weight 31 kD of c33-c viral protein was shown to account for 14% of the total cellular soluble proteins. This product was extracted
