1.Develonment and application of TaqMan MGB probe real-time fluorescence quantitative PCR for rapid detection of Helicobacter hepaticus
Zhengqin GAO ; Jin XING ; Yufang FENG ; Bingfei YUE ; Zhengming HE
Chinese Journal of Microbiology and Immunology 2011;31(9):833-838
Objective To develop a TaqMan MGB probe-based,sensitive and specific real-time fluorescence quantitative PCR assay for rapid detection of Helicobacter hepaticus.Methods Primers and probes specific toflaB gene of Helicobacter hepaticus were designed.A TaqMan MGB probe-based,real-time fluorescence quantitative PCR was established.The specificity,sensitivity and stability of the assay were assassed.Then,the established TaqMan MGB probe real-time fluorescence quantitative PCR assay was applied to detect Helicobacter hepaticus in 1081 clinical specimens during 2008-2011,compared with bacterial isolation and culture method and conventional PCR assay.Results The specificity of this established TaqMan MGB probe-based real-time fluorescence quantitative PCR was high and there were no cross-reactivity with Helicobacter pylori,Campylobacter jejuni,Clostridium piliforme,Pasteurella pneumotropica,Escherichia coli,Pseudomonas aeruginosa.The detection limits was 8.3 copies.The correlation coefficient and slope value of standard curve were 0.999 and -3.227,respectively and the efficiency of TaqMan MGB-based probe realtime fluorescence quantitative PCR assay was 100%.The TaqMan MGB-based probe real-time fluorescence quantitative PCR and conventional PCR were preformed to detect Helicobacter hepaticus in 1081 clinical specimens,a total of 86 specimens were positive for Helicobacter hepaticus.However,there was only 4 specimens were positive by bacteria isolation and culture method.The results showed that TaqMan MGB -based probe real-time fluorescence quantitative PCR for Helicobacter hepaticas was more sensitive than bacteria isolation and culture method,and it could detect Helicobacter hepaticus DNA from clinical specimens directly,and detection time is only 2 hours.Conclusion The TaqMan MGB-based probe real-time fluorescence quantitative PCR assay was a reliable,specific,sensitive and useful tool for rapid detection of Helicobacter hepaticus.
2.Phenotypic analysis of Pasteurella pneumotropica in laboratory animals in Beijing area
Jin XING ; Yufang FENG ; Bingfei YUE ; Zhengming HE
Chinese Journal of Comparative Medicine 2014;(6):54-57
Objective To improve the accuracy of detection through analyzing the phenotypes of P.pneumotropica isolates in laboratory animals in Beijing area .Methods 306 suspicious P.pneumotropica strains were identified by biochemical identification and 16S rDNA sequencing.Then, to obtain the phylogenetic relationships combined with colony characteristics on blood agar plates and biochemical characteristics of 53 biotypes .Results BD Phoenix 100 automated bacterial identification system and 16S rDNA sequencing identified P.pneumotropica positive rate of 306 isolates were 164/306 and 227/306, respectively.There were 140 phenotypes in 227 true-positive strains, of which 106 were biotype Heyl and 23 were biotype Jawetz .Conclusions In the samples of laboratory animals in Beijing area , P.pneumotropica infection mainly are of biotype Heyl , and less is of biotype Jawetz .The phenotypes are diverse and widely distributed .
3.Investigation of Leptospira infection in three new experimental animals by PCR methods
Yufang FENG ; Jin XING ; Wei GONG ; Bingfei YUE ; Zhengming HE
Chinese Journal of Comparative Medicine 2014;(8):31-35,66
Objective To establish an effective PCR assay for leptospirosis detection , and applicate the assay in tree shrew, mongolian gerbil and gray hamster .Methods Sequence of leptospira was obtained from the NCBI Genbank , and primers were designed based on the sequences .The positive amplified fragments were sequenced to verify the reliability of the method.The samples from tree shrew, mongolian gerbils and hamsters were tested using this PCR method .Results The PCR method for detection of leptospirosis was successfully established .The positive rate of Leptospira was 8.33% in 60 samples of conventional tree shrews , 100% in 104 samples of the conventional Mongolian gerbils , and 0% in 60 samples of clean gray hamsters.Conclusions The establishment of this PCR assay is useful in the detection of leptospirosis in tree shrew, mongolian gerbil and gray hamster .The results of our investigation of leptospira infection levels of the three new experimental animals may promote their application in biomedical research .
5.Development and application of a multiplex PCR assay for pathogenic dermatophytes in laboratory animals
Jin XING ; Yufang FENG ; Bingfei YUE ; Zhengming HE
Chinese Journal of Comparative Medicine 2015;(12):65-70
Objective To develop a multiplex polymerase chain reaction ( mPCR) assay for detection of four pathogenic dermatophytes [Trichophyton mentagrophytes (Tm), Microsporum gypseum (Mg), Microsporum canis (Mc), and Arthroderma simii ( As) ] in laboratory animals, which could be used rapidly and simultaneously for direct detection of those four pathogens.Methods We designed 5 specific primers according to 18S-28S rRNA sequences of the four pathogenic dermatophytes reported in Genbank. The four mPCR assays were established through optimizing the concentration of primers, dNTP, TaqDNA polymerase and the annealing temperature.After verifying the specificity and sensibility, this method was used to detect 15 hair samples with artificial infection and 260 samples taken from laboratory animals.Results This mPCR technique can distinguish the four dermatophytes by producing 192 bp( Tm) ,460 bp( Mg) , 290 bp( Mc) and 602 bp( As) fragments.The sensibility for detection of the four dermatophytes was 5.9 pg/μL, 6.6 pg/μL, 9.5 pg/μL and 5.1 pg/μL, respectively.The results of 15 artificial infection samples were accurate, and the results of 260 hairs samples were negative for the four fungi.Conclusions Our results suggest that the mPCR assay developed in this study can efficiently detect the four dermatophytes, is a useful and rapid technique for rapid detection of the pathogenic dermatophytes in laboratory animals.
6.Establishment and application of a PCR method for detection of Bartonella in tree shrew
Yufang FENG ; Jin XING ; Rui FU ; Wei GONG ; Zhengming HE ; Bingfei YUE
Chinese Journal of Comparative Medicine 2014;(6):69-72
Objective To establish an effective PCR assay for detection of Bartonella, and application of this assay in tree shrew .Methods Sequence of Bartonella was obtained from NCBI Genbank .Three pairs of primers were designed based on this sequence .One pair of primers was determined through amplifying the major strains in China .Sixty tree shrew blood samples were tested with this PCR assay .The positive amplified fragments were sequenced to verify the reliability of this method .Results A PCR method for detection of Bartonella is successfully established , with a high specificity and the sensitivity was of 2.0 ×10 -5 μg/mL.Among the tested 60 blood samples , 15 positive cases were detected.Sequencing of the samples confirmed a 25%infection rate of Bartonella in the tree shrews, well consistent with the amplification results , and verified the applicability of this detection method .Conclusion The establishment of this method provides the basis for detection of Bartonella in tree shrew.
7.Expression changes of Rhodopsin and recoverin in MNU-induced photoreceptor degeneration in rats
Wei, JIN ; Yi-Qiao, XING ; Hai-Feng, MEI ; Wen-Jun, WANG ; An-Huai, YANG
International Eye Science 2014;(10):1755-1759
AIM: To investigate the time - effect relationship between the expression of rhodopsin and recoverin and photoreceptor damage induced by N - nethl - N -nitrosourea ( MNU) .
METHODS: Thirty-six 7-week old Sprague-Dawley ( SD ) rats were intraperitoneally injected with MNU ( 60mg/kg ) and were put to death by dislocation of cervical vertebra 6, 12, 24h; 3, 7d after injection ( 6 per group) , respectively. As a control, six rats were injected with phosphate buffer saline (PBS) 5mL/kg and sacrificed on d3 after injection. The degree of photoreceptor apoptosis was detected by HE staining, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling ( TUNEL ) and transmission electron microscope ( TEM ) in the right eyes. The mRNA expressions of rhodopsin and recoverin were detected different time after injection by Western blot and immunohistochemical method in the left eyes.
RESULTS:The dissolution of photoreceptor nucleus and apoptosis body were first perceived at 12h by TEM; most of cells at outer nuclear layer were presented positive reaction. The apoptotic index reached peak ( 29. 7% ±2.3%) at 24h which was coincided with the observation of TEM. The results of immunohistochemistry displayed that rhodopsin and recoverin were on a declining curve with time extension. Furthermore, the results of Western blot indicated that rhodopsin had dramatic decline at 6h after injection (P<0. 05), and extremely significant difference comparing to control group after 12h ( P<0. 01 ); while recoverin dramatic declined at 12h, and extremely significant difference after 24h (P<0. 01).
CONCLUSION:60mg/kg MNU intraperitoneally injection one - time may specifically induce photoreceptor apoptosis, The mechanism of down - regulation of rhodopsin and recoverin may be related to the selected apoptosis of photoreceptors.
8.Establishment and application of CODEHOP PCR assay for detection of Pasteurella spp.in laboratory animals
Jin XING ; Yufang FENG ; Bingfei YUE ; Zhengming HE ; Xiaomei SUN ; Jiejie DAI
Chinese Journal of Comparative Medicine 2017;27(1):85-90
Objective We established a rapid detection method of Pasteurella spp.and provided a reference for microbiological quality control of laboratory animal .Methods According to the β subunit of bacterial RNA polymerase ( rpoB) protein multiple alignments of 13 different Pasteurella spp.published in NCBI .The degenerate primers were designed by CODEHOP designer online .CODEHOP PCR method was applied to detecting Pasteurella spp.after the specificity and sensitivity of the method had been evaluated by 21 reference strains .Results Standard strain amplified fragment were about 200 bp by degenerate primers PastF6/PastR5.The primers are able to distinguish between Pasteurella spp.and the other pathognic organisms of laboratory animal respiratory tracts .Sensitivity of this method were 0.2 pg/μL~2 pg/μL to different Pasteurella.The Pasteurella positive rate was 19.1% in 609 animal ' s respiratory samples .The accuracy of positive results was 100%through verifying by sequenced and blast .Conclusions The established method has good specificity and sensitivity .It can be used to detect Pasteurella spp.in animal samples .
9.Establishment of a detection method for Helicobacter pylori in living Mongolian gerbil
Cunlong WANG ; Changlong LI ; Jin XING ; Yufang FENG ; Xiaoyan DU ; Bingfei YUE ; Zhengming HE ; Zhenwen CHEN
Chinese Journal of Comparative Medicine 2017;27(3):75-80
Objective To establish a detection technique for H.pylori(HP) infection in Mongolian gerbils using nested PCR technique.Methods H.pylori was cultured in vitro and inoculated into Mongolian gerbils.At the 10th week after infection, the HP in the gastric juice of Mongolian gerbil was detected by conventional PCR assay and the gastric juice, gastric mucosa, duodenal contents and colon stool were examined by nested PCR.Rapid urease test and ELISA were used to analyze the accuracy of the nested PCR assay.All of the PCR products were verified by sequencing.Results The positive rate of gastric juice detected by conventional PCR was 30%, while the positive rates of gastric juice, gastric mucosa, duodenal contents and colon stool detected by nested PCR were 100%, 100%, 90%, and 10%, respectively.The positive detection rates of rapid urease test and serum ELISA were 100% and 0%, respectively.Comparing the results of different methods, both the positive rates of gastric juice and gastric mucosa detected by nested PCR and the detection rate of rapid urease test were 100%, but the results of conventional PCR detection of gastric juice, the nested PCR detection result of stool in colon and of serum ELISA assay were lower than other methods.Conclusions Due to its high accuracy and sensitivity, the nested PCR assay of gastric juice can be used for the long-time detection of H.pylori infection in Mongolian gerbils, especially useful in the experiments of prevention and treatment of H.pylori infection.
10.A case of prune belly syndrome.
Zhan-kui LI ; Jin-xing FENG ; Zheng-qi CHEN ; Erdi XU ; Chun-yan ZHAO
Chinese Journal of Pediatrics 2004;42(10):798-798