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 .

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.

BACKGROUND: The particular bystander effect of suicide gene can remarkably kill tumor cells. Meanwhile, it can be used together with radiotherapy as well as immune gene therapy, and overcome the defect of low gene transduction efficiency.Cytosine deaminase (CD) can generate a powerful bystander effect.OBJECTIVE: To observe the effect of a eukaryotic expression plasmid plRES2-AcGFP1-CD mediated by liposome transfected into bone marrow mesenchymal stem cells (BMSCs) and its gene expression.DESIGN, TIME AND SETTING: A cytologic experiment at genetic level was performed at Research and Development Center of Stem Cell and Tissue Engineering, Dalian University of Technology from May to December 2007.MATERIALS: A total of 6 C57BL mice of SPF degree and weighing 18-20 g were used for separation and culture of BMSCs.Escherichia coli DH5a was provided by Research and Development Center of Stem Cell and Tissue Engineering, Dalian University of Technology. Lipofectamine~(TM) 2000 was provided by Invitrogen, China.METHODS: The DNA plasmids were extracted from transformed Escherichia coli DH5a. plRES2-AcGFP1-CD plasmid was identified by BamHI/Xhol double digestion. The BMSCs derived from mouse femur and tibia were cultured and purified by adhesion method in vitro. Signal cell suspension prepared by BMSCs of the third generation was cultured by adding fluorescence-labeled CD44, CD45, CD90 and CD105 antibodies. BMSCs of the third generation were transfected by LipofectamineTM 2000 mediation.MAIN OUTCOME MEASURES: Identification of recombinant plasmids; the expressions of surface markers on BMSCs were detected by flow cytometry; the expressions of cytosine deaminase gene were observed at 36 and 48 hours after transfection under fluorescent inverted microscope.RESULTS: After agarose gel electrophoresis, a band appeared at 1.0-1.5 kb of the digested products of plRES2-AcGFP1-CD plasmids, and the band was accorded with the length of cytosine deaminase gene in the length. Flow cytometry demonstrated that the cells were negative for CD45 but positive for CD44, CD90 and CD105. Fluorescent inverted phase contrast microscope suggested that at 36 hours after plRES2-AcGFP1-CD gene transfection an expression of green fluorescent protein was found in the BMSCs; additionally, at 48 hours after transfection, the expression of green fluorescent protein remained and the intensity was remarkably increased.CONCLUSION: The liposome-mediated plRES2-AcGFP1-CD gene successfully expressed in BMSCs, and the expression peaked at 48 hours after transfection.

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.

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 .

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.

Objective To investigate the effects of penehyclldine hydrochloride postconditioning on hind limb ischemia-reperfusion (I/R) injury in rats. Methods One hundred and forty-four male Wistar rats weighing 220-250 g were randomly divided into 4 groups (n = 36 each): control group (group C), I/R group, ischemic postconditioning group (group IPO) and penehyclidine hydrochloride postconditioning group (group PHPO). Limb ischemia was induced by occlusion of bilateral hind limb for 3 h followed by 24 h reperfusion. In group IPO, the animals were subjected to three cycles of 30 s reperfusion and 30 s ischemia on the proximal part of the hind limb,while in group PHPO, the animals received iv injection of penehyclidine hydrochloride 0.15 mg/kg (in normal saline 1 wl) via the caudal vein immediately after reperfusion. Blood samples from the inferior vena cava were taken for determination of activities of serum LDH and CK and concentrations of TNF-α and IL-10 at O, 1, 3, 6, 12 and 24 h of reperfusion. Then 6 rats were sacrificed at each time point respectively and the quadriceps femoris tissues of the hind limb were removed for determination of MDA content, activities of SOD, MPO, Na+ -K+-ATPase and Ca2 + - Mg2+ -ATPase, and HIF- 1 α expression and microscropic examination. Results Compared with group C, the activities of serum LDH and CK and concentrations of TNF-α and IL-10 were significantly increased, the activities of SOD, Na+-K+-ATPase and Ca2+-Mg2+-ATPase were decreased, MPO activities and MDA content were increased, HIF-1α expression was up-regulated in group I/R, IPO and PHPO (P ＜0.05 or 0.01). Compared with group I/R, the serum activities of serum LDH and CK and TNF-α concentration were significantly decreased, IL- 10concentration was increased, activities of SOD, Na+ -K+ -ATPase and Ca2+ -Mg2+ -ATPase were increased, and MPO activity and MDA content were decreased, HIF-1α expression was down-regulated (P ＜ 0.01), and the pathologic changes was reduced in group IPO and PHPO. Compared with group IPO, the serum LDH activity and TNF-α concentration were significantly decreased, CK activity and IL-10 concentration were increased, activities of SOD and MPO and MDA content were decreased and HIF-1α expression was down-regulated (P ＜ 0.05 or 0.01).Conclusion Penehyclidine hydrochloride postconditioning can reduce hind limb I/R injury in rats, and the mechanism is related to inhibiting inflammatory response and lipid peroxidation, reducing calcium overload and improving cellular energy metabolism.

Objective To verify the detection ability of experimental animal quality detection laboratories in China for Staphylococcus aureus.Methods The testing samples for Staphylococcus aureus detection were prepared by bacterial culture, homogeneity test and stability test, according to the study plan approved by CNAS.Then the samples and operation instruction were sent to the participant laboratories.The detection reports from these laboratories should be submitted before the deadline expires, and the collected data were summarized and analyzed.Results There were 28 laboratories which joined to this test plan.Among them 22 laboratories ( 78.57%) achieved satisfactory test results, and six laboratories (21.43%) had unsatisfactory test results.27 Laboratories used the national standard detection assay, while only one labo-ratory used PCR assay.Conclusions Most of experimental animal quality testing laboratories in China have sufficient pro-ficiency in detection of Staphylococcus aureus.The obtained information are very helpful for the laboratory ability verification testing in future.

Objective To establish a real-time quantitative PCR ( qPCR) method for detection of Streptobacillus moniliformis, which can be used to rapidly detect this pathogen in laboratory animals .Method According to the S. moniliformis sequences published in NCBI , we designed specific primers and MGB probe .The specificity, sensitivity and stability of this method were evaluated using 24 standard reference strains .Total of 823 respiratory specimens of animals including mice, rats, guinea pigs, hamsters, rabbits, Mongolian gerbils and tree shrews , were detected by this established Taqman MGB qPCR method .Results We had successfully established the S.moniliformis Taqman MGB qPCR method . S.moniliformis was not detected in the samples of mice , rats, guinea pigs, hamsters and rabbits.The positive rate of S. moniliformis was 1.5% ( 1/65 ) and 61.7% ( 37/60 ) in conventional Mongolian Gerbils and tree shrews , respectively . Conclusions Our developed qPCR method can be used to effectively detect S.moniliformis in laboratory animals .Moreover , its accuracy and sensitivity are better than the national standard method .This study laid the foundations for optimizing the quality inspection system of laboratory animals .