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PubMed | Chinese Academy of Fishery Sciences and Guangdong Laboratory Animals Monitoring Institute
Type: | Journal: Journal of veterinary pharmacology and therapeutics | Year: 2016

Increasing prevalence of extended-spectrum -lactamase (ESBL)-producing Klebsiella pneumoniae (K.pneumoniae) is of clinical concern. The objective of our study was to examine the invivo activity of cefquinome against ESBL-producing K.pneumoniae strain using a neutropenic mouse thigh infection model. Cefquinome kinetics and protein binding in infected neutropenic mice were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Dose-fractionation studies over a 24-h dose range of 2.5-320mg/kg were administered every 3, 6, 12, or 24h. The percentage of the dosing interval that the free-drug serum levels exceed the MIC (%fT>MIC) was the PK-PD index that best correlated with cefquinome efficacy (R

PubMed | Guangdong Laboratory Animals Monitoring Institute and Sun Yat Sen University
Type: | Journal: BMC genomics | Year: 2016

Pig (Sus scrofa) is a major source of dietary proteins for human consumption and is becoming a valuable model in agricultural and biomedical research. The recently developed isobaric tag for relative and absolute quantitation (iTRAQ) method allows sensitive and accurate protein quantification. Here, we performed the first iTRAQ-based quantitative proteomic analyses of Landrace (LR) and Wuzhishan (WZS) pig longissimus dorsi muscle tissues during early embryonic development.The iTRAQ-based early embryonic longissimus dorsi muscle study of LR and WZS ranging from 21 to 42 days post coitus (dpc) identified a total of 4431 proteins from 17,214 peptides, which were matched with 36,4025 spectra at a false discovery rate of 5%. In both WZS and LR, the largest amount of differentially expressed proteins (DEPs) were found between 28 and 35 dpc. 252 breed-DEPs were selected by GO analysis, including 8 myofibrillar proteins. Only MYHCI/IIA mRNA were detected due to early embryonic stages, and significantly higher expression of them were found in WZS during these 4 stages. MYHCI was first found in WZS at 28 dpc and expressed in both breeds at later stages, while MYHCII protein was not detected until 35 dpc in both breeds. Thus, 33 myogenic breed-DEPs selected from last two stages were analyzed by STRING, which showed that some myofibrillar proteins (MYH1, TPM4, MYH10, etc.) and functional proteins (CSRP2, CASQ2, OTC, etc.), together with candidate myogenic proteins (H3F3A, HDGFRP2, etc.), probably participate in the regulatory network of myofiber formation.Our iTRAQ-based early embryonic longissimus dorsi muscle study of LR and WZS provides new data on the in vivo muscle development distinctions during early embryonic development, which contributes to the improved understanding in the regulation mechanism of early myogenesis in agricultural animals.

PubMed | Guangdong Laboratory Animals Monitoring Institute, University of Hong Kong, Guangxi Medical University and Shantou University
Type: Journal Article | Journal: Journal of virology | Year: 2016

The H9N2 influenza viruses that are enzootic in terrestrial poultry in China pose a persistent pandemic threat to humans. To investigate whether the continuous circulation and adaptation of these viruses in terrestrial poultry increased their infectivity to pigs, we conducted a serological survey in pig herds with H9N2 viruses selected from the aquatic avian gene pool (Y439 lineage) and the enzootic terrestrial poultry viruses (G1 and Y280 lineages). We also compared the infectivity and transmissibility of these viruses in pigs. It was found that more than 15% of the pigs sampled from 2010 to 2012 in southern China were seropositive to either G1 or Y280 lineage viruses, but none of the sera were positive to the H9 viruses from the Y439 lineage. Viruses of the G1 and Y280 lineages were able to infect experimental pigs, with detectable nasal shedding of the viruses and seroconversion, whereas viruses of the Y439 lineage did not cause a productive infection in pigs. Thus, adaptation and prevalence in terrestrial poultry could lead to interspecies transmission of H9N2 viruses from birds to pigs. Although H9N2 viruses do not appear to be continuously transmissible among pigs, repeated introductions of H9 viruses to pigs naturally increase the risk of generating mammalian-adapted or reassorted variants that are potentially infectious to humans. This study highlights the importance of monitoring the activity of H9N2 viruses in terrestrial poultry and pigs.H9N2 subtype of influenza viruses has repeatedly been introduced into mammalian hosts, including humans and pigs, so awareness of their activity and evolution is important for influenza pandemic preparedness. However, since H9N2 viruses usually cause mild or even asymptomatic infections in mammalian hosts, they may be overlooked in influenza surveillance. Here, we found that the H9N2 viruses established in terrestrial poultry had higher infectivity in pigs than those from aquatic birds, which suggests that adaptation of the H9N2 viruses in terrestrial poultry might have increased the infectivity of the virus to mammals. Therefore, monitoring the prevalence and evolution of H9 viruses prevalent in terrestrial birds and conducting risk assessment of their threat to mammals are critical for evaluating the pandemic potential of this virus.

Li W.,Guangdong Medical College | Wu Y.,Guangdong Laboratory Animals Monitoring Institute | Min F.,Guangdong Medical College | Li Z.,Guangdong Medical College | And 2 more authors.
Metabolic Brain Disease | Year: 2010

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by progressive cognitive impairment and neuropathological changes, including the deposition of amyloid-beta (Aβ) peptide. Aged monkeys have proven to be invaluable in the study of AD, as their brains naturally develop amyloid plaques similar to those in AD brains. However, spontaneous development of AD-like pathologies in aged monkeys is time-consuming, often taking several years. Here, we created an experimentally induced AD model in middle-aged (16-17 years) rhesus monkeys by intracranial injection of Aβ42 and thiorphan, an inhibitor of neprilysin that is responsible for Aβ clearance. The working memory capacity of the monkeys in a delayed-response task was little affected following the delivery of Aβ42 and thiorphan. However, the administration of Aβ42 and thiorphan resulted in a significant intracellular accumulation of Aβ in the neurons of the basal ganglia, the cortex, and the hippocampus, accompanied by neuronal atrophy and loss. Moreover, immunohistochemistry revealed a degeneration of choline acetyltransferase-positive cholinergic neurons and an increase of glial fibrillary acidic protein-positive astrocytes. In conclusion, our data demonstrate a primate model of AD generated by combined infusion of Aβ42 and thiorphan, which duplicates a subset of neuropathological changes in AD brains, thereby having implications in the elucidation of this disease. © 2010 Springer Science+Business Media, LLC.

Min F.,Guangdong Laboratory Animals Monitoring Institute | Zhang Y.,Guangdong Laboratory Animals Monitoring Institute | Pan J.,Guangdong Laboratory Animals Monitoring Institute | Wang J.,Guangdong Laboratory Animals Monitoring Institute | Yuan W.,Guangdong Laboratory Animals Monitoring Institute
Experimental Animals | Year: 2013

Tuberculosis (TB) in nonhuman primates is a serious menace to the welfare of the animals and human who come into contact with them, while the rapid, accurate, and robust diagnosis is challenging. In this study, we first sought to establish an appropriate primate TB model resembling natural TB in nonhuman primates. Four rhesus monkeys (Macaca mulatta) of Chinese origin were infected intratracheally with two low doses of M. tuberculosis H37Rv. Regardless of the infectious doses, all monkeys were demonstrated to be successfully infected by clinical assessments, tuberculin skin test conversions, peripheral immune responses, gross observations, histopathology analysis, and M. tuberculosis burdens. Furthermore, we extended the usefulness of this model for assessing the following immunodiagnostic antigens: CFP10, ESAT-6, CFP10-ESAT-6, and an antigen cocktail of CFP10 and ESAT-6. The data showed that CFP10 was an M. tuberculosis-specific, "early" antigen used for serodiagnosis of TB in nonhuman primates. In conclusion, we established a useful primate TB model depending on low doses of M. Tuberculosis and affording new opportunities for studies of M. tuberculosis disease and diagnostics. © 2013 Japanese association for Laboratory animal Science.

PubMed | Guangdong Laboratory Animals Monitoring Institute
Type: Comparative Study | Journal: Experimental animals | Year: 2016

Recent evidence indicates that the prevalence of diseases caused by nontuberculous mycobacteria (NTM) has been increasing in both human and animals. In this study, antibody profiles of NTM in rhesus monkeys (Macaca mulatta) were determined and compared with those of monkeys infected with Mycobacterium tuberculosis complex (MTBC). Antibodies against 10 M. tuberculosis proteins, purified protein derivative (PPD), and mammalian old tuberculin (MOT) were detected in 14 monkeys naturally infected with NTM by indirect ELISA. Sera from 10 monkeys infected with MTBC and 10 healthy monkeys were set as controls. All antigens showed high serological reactivities to MTBC infections and low reactivities in healthy monkeys. NTM infections showed strong antibody responses to MOT and PPD; moderate antibody responses to 16kDa, U1, MPT64L, 14kDa, and TB16.3; and low antibody responses to 38kDa, Ag85b, CFP10, ESAT-6, and CFP10-ESAT-6. According to the criteria of MTBC, only CFP10, ESAT-6, and CFP10-ESAT-6 showed negative antibody responses in all NTM infections. Taken together, these results suggest that positive results of a PPD/MOT-based ELISA in combination with results of antibodies to M. tuberculosis-specific antigens, such as CFP10 and ESAT-6, could discriminate NTM and MTBC infections. Two positive results indicate an MTBC infection, and a negative result for an M. tuberculosis-specific antigen may preliminarily predict an NTM infection.

PubMed | Guangdong Laboratory Animals Monitoring Institute
Type: | Journal: Journal of virological methods | Year: 2016

Theilers murine encephalomyelitis virus (TMEV) and rat theilovirus (RTV), the member of the genus Cardiovirus, are widespread in laboratory mice and rats, and are potential contaminants of biological materials. Cardioviruses infection may cause serious complications in biomedical research. To improve the efficiency of routine screening for Cardioviruses infection, a duplex real-time reverse transcriptase polymerase chain reaction (RT-PCR) assay was developed for simultaneous detection and differentiation of TMEV and RTV. The duplex assay was specific for reference strains of TMEV and RTV, and no cross-reaction was found with seven other rodent viruses. The limits of detection of both TMEV and RTV were 410(1) copies RNA/reaction. Reproducibility was estimated using standard dilutions, with coefficients of variation <3.1%. 439 clinical samples were evaluated by both duplex real-time RT-PCR and conventional RT-PCR. For 439 clinical samples95 samples were positive for TMEV and 72 samples were positive for RTV using duplex real-time RT-PCR approach, whereas only 77 samples were positive for TMEV and 66 samples were positive for RTV when conventional RT-PCR was applied. Mixed infections were found in 20 samples when analyzed by conventional RT-PCR whereas 30 samples were found to be mixed infection when duplex real-time RT-PCR was applied. This duplex assay provides a useful tool for routine health monitoring and screening of contaminated biological materials of these two viruses.

PubMed | Guangdong Laboratory Animals Monitoring Institute and CAS Institute of Microbiology
Type: | Journal: Veterinary medicine international | Year: 2015

This study was to establish a systemic C. parapsilosis infection model in immunosuppressed ICR mice induced by cyclophosphamide and evaluate the antifungal efficiency of fluconazole. Three experiments were set to confirm the optimal infectious dose of C. parapsilosis, outcomes of infectious model, and antifungal efficiency of fluconazole in vivo, respectively. In the first experiment, comparisons of survival proportions between different infectious doses treated groups showed that the optimal inoculum for C. parapsilosis was 0.9 10(5) CFU per mouse. The following experiment was set to observe the outcomes of infection at a dose of 0.9 10(5) CFU C. parapsilosis. Postmortem and histopathological examinations presented fugal-specific lesions in multiorgans, especially in kidneys, characterized by inflammation, numerous microabscesses, and fungal infiltration. The CFU counts were consistent with the histopathological changes in tissues. Th1/Th2 cytokine imbalance was observed with increases of proinflammatory cytokines and no responses of anti-inflammatory cytokines in sera and kidneys. In the last experiment, model based evaluation of fluconazole indicated that there were ideal antifungal activities for fluconazole at dosages of 10-50mg/kg/d. Data demonstrates that the research team has established a systemic C. parapsilosis infection model in immunosuppressed ICR mice, affording opportunities for increasing our understanding of fungal pathogenesis and treatment.

PubMed | Guangdong Laboratory Animals Monitoring Institute and Livzon MabPharm Inc.
Type: Journal Article | Journal: Biology open | Year: 2016

Tumor necrosis factor alpha (TNF) plays a key role in the pathogenesis of rheumatoid arthritis (RA). Blockade of TNF by monoclonal antibody has been widely used for the therapy of RA since the 1990s; however, its mechanism of efficacy, and potential safety concerns of the treatment are still not fully understood. This study sought to establish a transgenic arthritic mouse model by overexpressing human TNF (hTNF) and to apply this model as a means to evaluate therapeutic consequences of TNF inhibitors. The transgenic mouse line (TgTC) with FVB background was generated by incorporating 3-modifiedhTNFgene sequences. A progressively erosive polyarthritis developed in the TgTC mice, with many characteristics observed in human rheumatoid arthritis, including polyarticular swelling, impairment of movement, synovial hyperplasia, and cartilage and bone erosion. Gene expression analysis demonstrated that hTNF is not only expressed in hyperplastic synovial membrane, but also in tissues without lesions, including brain, lung and kidney. Treatment of the TgTC mice with anti-hTNF monoclonal antibodies (mAb) significantly decreased the level of hTNF in the diseased joint and effectively prevented development of arthritis in a dose-dependent response fashion. Our results indicated that the TgTC mice represent a genetic model which can be used to comprehensively investigate the pathogenesis and therapeutics of TNF-related diseases.

PubMed | Guangdong Laboratory Animals Monitoring Institute and Guangdong Academy of Agricultural Sciences
Type: Journal Article | Journal: Virus genes | Year: 2016

A new family of IFNs called type III IFN or IFN- has been described, and shown to induce antiviral activity against several viruses in the cell culture. In this study, the molecular cloning, expression, and antiporcine epidemic diarrhea virus (PEDV) activity of porcine IFN-3 (poIFN-3) were reported. The full-length poIFN-3 cDNA sequence encoded 196 amino acids with a 23 amino acid signal peptide. Sequence alignments showed that poIFN-3 had an amino acid sequence similarity to Ovis aries (78.1%), Bos taurus (76.0%), Tupaia belangeri (71.3%), Equus caballus (69.9%), and Homo sapiens (69.9%). The phylogenetic analysis based on the genomic sequences indicated that poIFN-3 is located in the same branch as B. taurus and O. aries IFN-3. The poIFN-3 without a signal anchor sequence was efficiently expressed in Escherichia coli, and the purified recombinant poIFN-3 exhibited significant antiviral effects against PEDV in a dose- and time-dependent manner. This inhibitory effect of poIFN-3 on PEDV was observed under three different treatment conditions. The highest inhibition of PEDV was observed in Vero E6 cell cultures pretreated with poIFN-3 (prior to PEDV infection). In addition, poIFN-3 was able to induce the expression of IFN-stimulated genes, including ISG15, OAS1, and Mx1 in Vero E6 cells. These data demonstrate that poIFN-3 has antiviral activity against PEDV and may serve as a useful biotherapeutic candidate to inhibit PEDV or other viruses in swine.

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