Direct RNA Sequencing of Foot-and-mouth Disease Virus Genome Using a Flongle on MinION.

Foot-and-mouth disease (FMD) is a severe and extremely contagious viral disease of cloven-hoofed domestic and wild animals, which leads to serious economic losses to the livestock industry globally. FMD is caused by the FMD virus (FMDV), a positive-strand RNA virus that belongs to the genus Aphthovirus, within the family Picornaviridae. Early detection and characterization of FMDV strains are key factors to control new outbreaks and prevent the spread of the disease. Here, we describe a direct RNA sequencing method using Oxford Nanopore Technology (ONT) Flongle flow cells on MinION Mk1C (or GridION) to characterize FMDV. This is a rapid, low cost, and easily deployed point of care (POC) method for a near real-time characterization of FMDV in endemic areas or outbreak investigation sites. Key features • Saves ~35 min of the original protocol time by omitting the reverse transcription step and lowers the costs of reagents and consumables. • Replaces the GridION flow cell from the original protocol with the Flongle, which saves ~90% on the flow cell cost. • Combines the NGS benchwork with a modified version of our African swine fever virus (ASFV) fast analysis pipeline to achieve FMDV characterization within minutes. Graphical overview Schematic of direct RNA sequencing of foot-and-mouth disease virus (FMDV) process, which takes ~50 min from extracted RNA to final loading, modified from the ONT SQK-RNA002 protocol (Version: DRS_9080_v2_revO_14Aug2019).

Rapid Detection and Quick Characterization of African Swine Fever Virus Using the VolTRAX Automated Library Preparation Platform.

African swine fever virus (ASFV) is the causative agent of a severe and highly contagious viral disease affecting domestic and wild swine. The current ASFV pandemic strain has a high mortality rate, severely impacting pig production and, for countries suffering outbreaks, preventing the export of their pig products for international trade. Early detection and diagnosis of ASFV is necessary to control new outbreaks before the disease spreads rapidly. One of the rate-limiting steps to identify ASFV by next-generation sequencing platforms is library preparation. Here, we investigated the capability of the Oxford Nanopore Technologies' VolTRAX platform for automated DNA library preparation with downstream sequencing on Nanopore sequencing platforms as a proof-of-concept study to rapidly identify the strain of ASFV. Within minutes, DNA libraries prepared using VolTRAX generated near-full genome sequences of ASFV. Thus, our data highlight the use of the VolTRAX as a platform for automated library preparation, coupled with sequencing on the MinION Mk1C for field sequencing or GridION within a laboratory setting. These results suggest a proof-of-concept study that VolTRAX is an effective tool for library preparation that can be used for the rapid and real-time detection of ASFV.

MiR-153 is Involved in Testicular Ischemia/Reperfusion Injury by Directly Targeting FOXO3 and Regulating Spermatogonia Pyroptosis.

IRI often occurs after detorsion of testicular torsion, which can contribute to permanent damage to sperm production function due to spermatogonia pyroptosis. Mounting data manifest that miRNAs possess a function in the IRI progression. However, the miR-153 function in testicular IRI remains unclear. We aim to elucidate the regulatory mechanism of miR-153 in regulating spermatogonia pyroptosis in testicular IRI. We developed the mouse testicular torsion/detorsion (T/D) model and the oxygen-glucose deprivation/reperfusion (OGD/R) model to examine the miR-153 function in testicular IRI. The extent of testicular ischemic damage was evaluated through HE staining the testicular tissue. Various experimental methods, including Western blotting, QRT-PCR, MDA, SOD assays, and immunohistochemistry (IHC), were deployed to examine the miR-153 levels and the generation of ROS in the testicular tissues. Furthermore, we determined the FoxO3 levels and pyroptosis-related proteins in GC-1 cells. Cell viability was assessed using the CCK-8 assay. Finally, the connection between miR-153 and FoxO3 was verified by employing dual luciferase reporter gene assays and Ago2-RIP. In the testicular IRI, we noted a significant elevation in the pyroptosis-correlated proteins NLRP3, caspase-1 (CASP1), IL-1ß, and IL-18 levels. Furthermore, we noted a significant upregulation of miR-153 in the IRI testicular tissues and GC-1 cells treated with OGD/R, and the miR-153 upregulation increased cell pyroptosis. Conversely, the miR-153 downregulation and FoxO3 overexpression reduced cell pyroptosis. Subsequently, we validated that FoxO3 is a miR-153 target gene. During the OGD/R process, miR-153 increased cell pyroptosis in GC-1 cells by suppressing the FoxO3 expression. We identified that the regulation of testicular IRI-induced cell pyroptosis is mediated by miR-153 via its targeting of FoxO3.

EXO1/P53/SREBP1 axis-regulated lipid metabolism promotes prostate cancer progression.

Prostate cancer (PCa) is one of the most common malignant tumors affecting the male genitourinary system. However, there is currently a lack of effective treatments for patients with advanced prostate cancer, which significantly impacts men's overall health. Exonuclease 1 (EXO1), a protein with mismatch repair and recombination functions, has been found to play a vital role in various diseases. In our study, we discovered that EXO1 acts as a novel biomarker of PCa, which promotes prostate cancer progression by regulating lipid metabolism reprogramming in prostate cancer cells. Mechanistically, EXO1 promotes the expression of SREBP1 by inhibiting the P53 signaling pathway. In summary, our findings suggest that EXO1 regulated intracellular lipid reprogramming through the P53/SREBP1 axis, thus promoting PCa progression. The result could potentially lead to new insights and therapeutic targets for diagnosing and treating PCa.

Assessment and verification of chemical inactivation of peste des petits ruminants virus by virus isolation following virus capture using Nanotrap magnetic virus particles.

This study reports development and optimization of a new method for the assessment and verification of the inactivation of peste des petits ruminants virus (PPRV) by chemical agents, including Triton X-100 and commercially available viral lysis buffers. Virus inactivation was confirmed by virus isolation (VI) on Vero cells following capture of the potential residual viruses from treated samples using Nanotrap magnetic virus particles (NMVPs). Since chemical agents are cytotoxic, treated PPRV samples could not be used directly for VI on Vero cell monolayers; instead, they were diluted in Eagle's Minimum Essential Medium (EMEM) to neutralize cytotoxicity and then subjected to virus capture using NMVPs. The NMVPs and the captured viruses were then clarified on a magnetic stand, reconstituted in EMEM, and inoculated onto Vero cells that were examined for cytopathic effect (CPE). No CPE was observed on cells inoculated with treated viruses captured by NMVPs; but CPE was observed on cells inoculated with untreated viruses, including those captured by NMVPs. For further verification, the supernatants of the VI cultures (treated or untreated) were subjected to RNA extraction and PPRV-specific real-time RT-PCR (RT-qPCR). The cycle threshold values were undetectable for the supernatants of VI cultures inoculated with NMVPs reconstituted from treated PPRV but detectable for the supernatants of VI cultures inoculated with untreated PPRV or the NMVPs reconstituted from untreated PPRV, indicating complete inactivation of PPRV. This new method of verification of virus inactivation using NMVPs can be applied to other high impact viruses of agricultural or public health importance. IMPORTANCE Research including diagnosis on highly contagious viruses at the molecular level such as PCR and next-generation sequencing requires complete inactivation of the virus to ensure biosafety and biosecurity so that any accidental release of the virus does not compromise the safety of the susceptible population and the environment. In this work, peste des petits ruminants virus (PPRV) was inactivated with chemical agents, and the virus inactivation was confirmed by virus isolation (VI) using Vero cells. Since the chemical agents are cytotoxic, inactivated virus (PPRV) was diluted 1:100 to neutralize cytotoxicity, and the residual viruses (if any) were captured using Nanotrap magnetic virus particles (NMVPs). The NMVPs and the captured viruses were subjected to VI. No CPE was observed, indicating complete inactivation, and the results were further supported by real-time RT-PCR. This new protocol to verify virus inactivation can be applicable to other viruses.

FAP promotes clear cell renal cell carcinoma progression via activating the PI3K/AKT/mTOR signaling pathway.

OBJECTIVE: Herein, we aimed at exploring the FAP expression in clear cell renal cell carcinoma (ccRCC) along with its clinical implication. METHODS: Using computational tools analysis of different freely accessible gene databases, the expression pattern, clinical importance, co-expressed genes, and signaling pathways of FAP in ccRCC were thoroughly investigated. FAP expression was examined in clinical ccRCC specimens through qRT-PCR, western blotting and immunohistochemistry. Furthermore, in vitro and in vivo experiments were carried out using flow cytometry, CCK-8, wound-healing and Transwell assays, as well as xenograft tumor model, respectively. RESULTS: FAP levels were found to be significantly elevated in ccRCC based on bioinformatic data from public databases. Patients who exhibited higher expression levels of FAP had poorer prognoses, according to Kaplan-Meier analysis of survival data. In addition, diagnostic and prognostic value of FAP in ccRCC was figured out by ROC curve and prognostic nomogram model. In vitro study revealed that the over-expression FAP accelerated cell proliferation, migration as well as invasion, and suppressed cell apoptosis, but silencing of FAP had the opposite effect. FAP suppression reduced the PI3K/AKT/mTOR pathway's stimulation, whereas FAP up-regulation increased the stimulation of the pathway. Blocking the PI3K/AKT/mTOR signaling pathway with the dual PI3K/mTOR inhibitor BEZ235 repressesed cancer-promoting effect of FAP. Additionally, we found that the downregulation of FAP was effective at slowing tumor progression in vivo. CONCLUSION: It is possible that FAP could be a reliable biomarker for the diagnosis and prognosis of ccRCC because of its role in the ccRCC progression via triggering the PI3K/AKT/mTOR signaling pathway.

Biocompatibility and efficacy of prostatic urethral lift in benign prostate hyperplasia: an in vivo and in vitro study.

The study aimed to assess the biocompatibility and efficacy of a prostatic urethral lift (PUL) for benign prostatic hyperplasia (BPH). Human BPH-1 cells were co-cultured with implant anchors and sutures, and cytotoxicity was measured. Scanning electron microscopy (SEM) was used to observe adhesion and growth of cells and to evaluate implant biocompatibility. Fifteen male beagle dogs were randomly assigned to the surgical (n = 9) or sham-operated (n = 6) groups. The surgical group underwent cystotomy, and PUL was used to insert two implants in each lobe of the prostate to compress the enlarged prostate and dilate the urethra; the sham group underwent cystotomy without implant insertion. Compared with the control group, no significant difference in cell viability among the groups with different co-culture times of implant anchors and sutures (P > 0.05) was observed. SEM revealed good adhesion and growth of prostate cells on the implants. Improvements in urine flow rates remained stable at 7, 28, and 180 days after surgery, and the urethral diameter in the prostate region was significantly increased compared with that before surgery. PUL is a biocompatible and effective treatment for BPH, improving the urine flow rate without causing inflammation, tissue damage, or cytotoxic effects. Here, the basis for further PUL application was provided.

GREM1 is a potential biomarker for the progression and prognosis of bladder cancer.

BACKGROUND: Gremlin-1 (GREM1) is a protein closely related to tumor growth, although its function in bladder cancer (BCa) is currently unknown. Our first objective was to study the GREM1 treatment potential in BCa. METHODS: BCa tissue samples were collected for the detection of GREM1 expression using Western blot analysis and Immunofluorescence staining. Association of GREM1 expression with clinicopathology and prognosis as detected by TCGA (The Cancer Genome Atlas) database. The functional investigation was tested by qRT-PCR, western blot analysis, CCK-8, cell apoptosis, wound healing, and transwell assays. The interaction between GREM1 and the downstream PI3K/AKT signaling pathway was assessed by Western blot analysis. RESULTS: GREM1 exhibited high expression in BCa tissues and was linked to poor prognosis. Stable knockdown of GREM1 significantly inhibited BCa cell (T24 and 5637) proliferation, apoptosis, migratory, invasive, as well as epithelial-mesenchymal transition (EMT) abilities. GREM1 promotes the progression in BCa via PI3K/AKT signaling pathway. CONCLUSION: Findings demonstrate that the progression-promoting effect of GREM1 in BCa, providing a novel biomarker for BCa-targeted therapy.

MiR-195-5p is involved in testicular ischemia/reperfusion injury by directly targeting PELP1 and regulating spermatogonia pyroptosis.

BACKGROUND AND OBJECTIVE: Ischemia/reperfusion injury (IRI), which is characterized by testicular torsion and causes permanent impairment of spermatogenic function, is linked with pyroptosis. Studies have implicated endogenous small non-coding RNAs in IRI development across various organs. In this study, we elucidated the mechanism underlying miR-195-5p's action in regulating pyroptosis in testicular IRI. METHODS: We established two models, namely a testicular torsion/ detorsion (T/D) mouse model and an oxygen-glucose deprivation/reperfusion (OGD/R)-treated germ cell model. Hematoxylin and eosin staining was performed to evaluate the testicular ischemic injury. The expression of pyroptosis-related proteins and reactive oxygen species production in testis tissues were detected using Western blotting, quantitative real-time PCR, malondialdehyde and superoxide dismutase assay kits and immunohistochemistry. Cell viability and cytotoxicity were evaluated using CCK-8 and LDH assays, whereas expression patterns of inflammatory proteins were measured using ELISA, immunofluorescence, and western blot assays. miR-195-5p interaction with PELP1 was validated by conducting the luciferase enzyme reporter test. RESULTS: Pyroptosis-related proteins NLRP3, GSDMD, IL-1ß, and IL-18 were significantly upregulated following testicular IRI. A similar pattern was observed in the OGD/R model. miR-195-5p was significantly downregulated in mouse IRI testis tissue and OGD/R-treated GC-1 cells. Notably, miR-195-5p downregulation promoted whereas its upregulation attenuated pyroptosis in OGD/R-treated GC-1 cells. Furthermore, we found that PELP1 is a miR-195-5p target. miR-195-5p attenuated pyroptosis in GC-1 cells by inhibiting PELP1 expression during OGD/R, and this protective effect was blocked upon miR-195-5p downregulation. Collectively, these results indicated that miR-195-5p inhibits testicular IRI-induced pyroptosis by targeting PELP1, suggesting that it has the potential to serve as a novel target for the future development of therapies for testicular torsion.

MiR-124-3p inhibits tumor progression in prostate cancer by targeting EZH2.

Prostate cancer (PCa) is widespread cancer with significant morbidity and mortality rates. MicroRNAs (miRNAs) have been identified as important post-transcriptional modulators in various malignancies. This study investigated the miR-124-3p effect on PCa cell proliferation, infiltration, and apoptosis. EZH2 and miR-124-3p expression levels were measured in PCa tissues. PCa cell lines DU145 and PC3 were transfected with miR-124-3p inhibitors or analogs. EZH2 and miR-124-3p linkage was validated by conducting the luciferase enzyme reporter test. The cell viability and apoptosis were assessed by flow cytometry and MTT test. Cell movement was noted during infiltration using transwell assays. EZH2, AKT, and mTOR contents were assessed using qRT-PCR and western blotting. In clinical PCa specimens, miR-124-3p and EZH2 contents were inversely correlated. Further research has demonstrated that EZH2 is the miR-124-3p direct target. Furthermore, miR-124-3p overexpression reduced EZH2 levels and lowered cell viability, infiltration, and promoted cell death, whereas miR-124-3p silencing had the opposite effect. Overexpression of miR-124-3p decreased the phosphorylation level of AKT and mTOR, whereas miR-124-3p downregulation produced the opposite result. Our findings depict that miR-124-3p prevents PCa proliferative and invasive processes while promoting apoptosis by targeting EZH2.

Oleuropein attenuates testicular ischemia-reperfusion by inhibiting apoptosis and inflammation.

BACKGROUND: Ischemia-reperfusion injury (IRI) is the key reason of injury after testicular torsion and may eventually lead to male infertility. Oleuropein, a natural antioxidant isolated from Olea europaea, has shown beneficial effects in different models of ischemia. We evaluated the effects of oleuropein on testicular IRI and explored the underlying protective mechanisms. METHODS: A mouse testicular torsion/detorsion (T/D) model and an oxygen-glucose deprivation/reperfusion (OGD/R) germ cell model were established and treated with oleuropein. H&E staining was used to evaluate testicular pathological changes. Apoptosis and apoptosis-associated protein levels in testis tissues were assessed by TUNEL staining, immunohistochemical staining and western blot. Apoptosis levels and apoptosis-associated protein levels in GC-1 were evaluated by flow cytometry, immunofluorescence and western blot. Oxidative stress levels were assessed by malondialdehyde (MDA) and superoxide dismutase (SOD) kits. Cell viability and inflammatory protein levels were evaluated by CCK-8 assay coupled with qRT-PCR. RESULTS: Relative to the control group, SOD activity was markedly suppressed, while MDA, Bax, Caspase-3, TNF-α as well as IL-1ß levels were significantly increased in the T/D model and OGD/R model. However, all of the aforementioned alterations were relieved by oleuropein treatment. CONCLUSION: Our findings indicate that oleuropein may be a promising treatment option to attenuate testicular IRI via its anti-oxidant, anti-inflammatory as well as anti-apoptotic properties.

MiR-363-3p promotes prostate cancer tumor progression by targeting Dickkopf 3.

BACKGROUND: Prostate cancer (PCa) is a frequent malignant tumor worldwide with high morbidity along with mortality. MicroRNAs (miRNAs) have been identified as key posttranscriptional modulators in diverse cancers. Herein, we purposed to explore the impacts of miR-363-3p on PCa growth, migration, infiltration along with apoptosis. METHODS: The expressions of miR-363-3p along with Dickkopf 3 (DKK3) were assessed in clinical PCa specimens. We adopted the PCa cell line PC3 and transfected it using miR-363-3p repressors or mimic. The relationship of miR-363-3p with DKK3 was verified by a luciferase enzyme reporter assay. Cell viability along with apoptosis were determined by MTT assay coupled with flow cytometry analysis. Cell migration along infiltration were detected via wound healing, as well as Transwell assays. The contents of DKK3, E-cadherin, vimentin along with N-cadherin were analyzed via Western blotting accompanied with qRT-PCR. RESULTS: MiR-363-3p was found to be inversely associated with the content of DKK3 in clinical PCa specimens. Further investigations revealed that DKK3 was miR-363-3p's direct target. Besides, overexpression of miR-363-3p decreased the contents of DKK3, promoted cell viability, migration coupled with infiltration, and reduced cell apoptosis, while silencing of miR-363-3p resulted in opposite influence. Upregulation of miR-363-3p diminished E-cadherin contents but increased vimentin along with N-cadherin protein contents in PC3 cells; in contrast, miR-363-3p downregulation produced the opposite result. CONCLUSION: Our study indicates that miR-363-3p promotes PCa growth, migration coupled with invasion while dampening apoptosis by targeting DKK3.

Development of a real-time PCR assay for detection of African swine fever virus with an endogenous internal control.

Real-time PCR assays are highly sensitive, specific and rapid techniques for the identification of ASF virus (ASFV) (Section 3.8, OIE Terrestrial Manual, 2019). Although an ASFV p72 gene-based real-time PCR assay (a.k.a. the Zsak assay) (Journal of Clinical Microbiology, 2005, 43, 112) has been widely used for ASFV detection, several more ASFV whole genome sequences have become available in the 15 years since the design of the Zsak assay. In this study, we developed a new ASFV p72 gene-based real-time PCR after analysis of all currently available sequences of the p72 gene and multiplexed the new assay with a modified Zsak assay aiming to have a broader coverage of ASFV strain/isolates. To reduce false-negative detections, porcine house-keeping gene, beta actin (ACTB), was applied as an internal control. Eight ACTB sequences from the GenBank and 61 partial ACTB sequences generated in this study, and 1,012 p72 sequences from the GenBank and 23 p72 sequences generated at FADDL, were used for ACTB and ASFV primer and probe designs, respectively, to ensure broader host and ASFV coverage. Multiplexing ACTB in the reaction did not affect ASFV amplification. The multiplex assay was evaluated for strain/isolate coverage, sensitivity and specificity. The in silico analysis showed high ASFV strain/isolate coverage: 98.4% (978/994) of all p72 sequences currently available. The limit of detection (LOD) was 6 plasmid copies or 0.1-1 TCID50 /ml of ASFV isolates per reaction. Only targeted ASFV isolates and the viruses in the positive clinical samples were detected, indicating that the assay is highly specific (100% specificity). The test results of 26 ASFV isolates with different country origins showed that this newly developed multiplex assay performed better than the Zsak assay that has been widely accepted and used worldwide, indicating that it may be used as an alternative assay for ASFV detection.

Development and evaluation of multiplex real-time RT-PCR assays for the detection and differentiation of foot-and-mouth disease virus and Seneca Valley virus 1.

Foot-and-mouth disease virus (FMDV) causes a highly contagious and economically important vesicular disease in cloven-hoofed animals that is clinically indistinguishable from symptoms caused by Seneca Valley virus 1 (SVV-1). To differentiate SVV-1 from FMDV infections, we developed a SVV-1 real-time RT-PCR (RT-qPCR) assay and multiplexed with published FMDV assays. Two published FMDV assays (Journal of the American Veterinary Medical Association, 220, 2002, 1636; Journal of Virological Methods, 236, 2016, 258) targeting the 3D polymerase (3D) region were selected and multiplexed with the SVV-1 assay that has two targets, one in the 5' untranslated region (5' UTR, this study) and the other in the 3D region (Journal of Virological Methods, 239, 2017, 34). In silico analysis showed that the primers and probes of SVV-1 assay matched 98.3% of the strain sequences (113/115). The primer and probe sequences of the Shi FMDV assay matched 85.4% (806/944), and that of the Callahan FMDV assay matched 62.7% (592/944) of the sequences. The limit of detection (LOD) for the two multiplex RT-qPCR assays for SVV-1 was both 9 copies per reaction by cloned positive plasmids and 0.16 TCID50 per reaction by cell culture. The LOD for FMDV by both multiplex assays was 11 copies per reaction using cloned positive plasmids. With cell cultures of the seven serotypes of FMDV, the Shi assay (Journal of Virological Methods, 236, 2016, 258) had LODs between 0.04 and 0.18 TCID50 per reaction that were either the same or lower than the Callahan assay. Interestingly, multiplexing with SVV-1 increased the amplification efficiencies of the Callahan assay (Journal of the American Veterinary Medical Association, 220, 2002, 1636) from 51.5%-66.7% to 89.5%-96.6%. Both assays specifically detected the target viruses without cross-reacting to SVV-1 or to other common porcine viruses. An 18S rRNA housekeeping gene that was amplified from multiple cloven-hoofed animal species was used as an internal control. The prevalence study did not detect any FMDV, but SVV-1 was detected from multiple types of swine samples with an overall positive rate of 10.5% for non-serum samples.

Development of conventional and real time PCR assays for rapid species authentication of mammalian cell lines commonly used in veterinary diagnostic laboratories.

Mammalian cell lines are valuable tools in biomedical fields, with applications ranging from disease diagnosis to the production of biological reagents and vaccines. Here we report the development of new conventional (cPCR) and real time PCR (qPCR) assays for species identification of several mammalian kidney cell lines originated from swine, green monkey, hamster and bovine tissues that are extensively used in veterinary diagnostic laboratories. The PCR primers and probes were selected from highly conserved mitochondrial genes and analyzed in silico by nucleotide BLAST in the National Center for Biotechnology Information (NCBI) website to ensure target specificity. The assays were highly species-specific and had no cross-reactivity against other tested cell lines originated from different mammalian species. Assay sensitivity (limit of detection; LOD) was determined using serial dilutions of cell line DNA as template. The estimated LODs were between 2.95 and 48 pg (picogram) DNA/assay for cPCR, and between 1.5 × 10-3 and 4.8 × 10-2 pg DNA/assay for qPCR. Multiplex qPCR assays were developed for simultaneous detection of up to three species in a single assay. The multiplex qPCR assays exhibited the same sensitivity as the corresponding singleplex assays with the exception of the green monkey species that demonstrated a 10-100 fold decline in the sensitivity. Contamination of swine cells was detected in one of the rabbit cell lines. The contamination was further confirmed by Sanger and Next-Generation sequencing.

Development and validation of a highly sensitive real-time PCR assay for rapid detection of parapoxviruses.

Parapoxviruses (PaPVs) cause widespread infections in ruminants worldwide. All PaPVs are zoonotic and may infect humans after direct or indirect contact with infected animals. Herein we report the development and validation of a highly sensitive real-time PCR assay for rapid detection of PaPVs. The new assay (referred to as the RVSS assay) was specific for PaPVs only and had no cross-reactivity against other pox viruses. Using a recombinant plasmid as positive control, the analytical sensitivity of the assay was determined to be 16 genome copies of PaPV per assay. The amplification efficiency estimate (91-99%), the intra- and interassay variability estimate (standard deviation [SD]: 0.28-1.06 and 0.01-0.14, respectively), and the operator variability estimate (SD: 0.78 between laboratories and 0.28 between operators within a laboratory) were within the acceptable range. The diagnostic specificity was assessed on 100 specimens from healthy normal animals and all but 1 tested negative (99%). The diagnostic sensitivity (DSe) was assessed on 77 clinical specimens (skin/scab) from infected sheep, goats, and cattle, and all tested positive (100%). The assay was multiplexed with beta-actin as an internal positive control, and the multiplex assay exhibited the same DSe as the singleplex assay. Further characterization of the PaPV specimens by species-specific real-time PCR and nucleotide sequencing of the PCR products following conventional PCR showed the presence of Orf virus not only in sheep and goats but also in 1 bovid. The validated RVSS assay demonstrated high specificity, sensitivity, reproducibility, and ruggedness, which are critical for laboratory detection of PaPVs.

Development of a universal RT-PCR for amplifying and sequencing the leader and capsid-coding region of foot-and-mouth disease virus.

Foot-and-mouth disease (FMD) is a highly infectious viral disease of cloven-hoofed animals with debilitating and devastating consequences for livestock industries throughout the world. Key antigenic determinants of the causative agent, FMD virus (FMDV), reside within the surface-exposed proteins of the viral capsid. Therefore, characterization of the sequence that encodes the capsid (P1) is important for tracking the emergence or spread of FMD and for selection and development of new vaccines. Reliable methods to generate sequence for this region are challenging due to the high inter-serotypic variability between different strains of FMDV. This study describes the development and optimization of a novel, robust and universal RT-PCR method that may be used to amplify and sequence a 3kilobase (kb) fragment encompassing the leader proteinase (L) and capsid-coding portions (P1) of the FMDV genome. This new RT-PCR method was evaluated in two laboratories using RNA extracted from 134 clinical samples collected from different countries and representing a range of topotypes and lineages within each of the seven FMDV serotypes. Sequence analysis assisted in the reiterative design of primers that are suitable for routine sequencing of these RT-PCR fragments. Using this method, sequence analysis was undertaken for 49 FMD viruses collected from outbreaks in the field. This approach provides a robust tool that can be used for rapid antigenic characterization of FMDV and phylogenetic analyses and has utility for inclusion in laboratory response programs as an aid to vaccine matching or selection in the event of FMD outbreaks.

Current perspectives on the phylogeny of Filoviridae.

Sporadic fatal outbreaks of disease in humans and non-human primates caused by Ebola or Marburg viruses have driven research into the characterization of these viruses with the hopes of identifying host tropisms and potential reservoirs. Such an understanding of the relatedness of newly discovered filoviruses may help to predict risk factors for outbreaks of hemorrhagic disease in humans and/or non-human primates. Recent discoveries such as three distinct genotypes of Reston ebolavirus, unexpectedly discovered in domestic swine in the Philippines; as well as a new species, Bundibugyo ebolavirus; the recent discovery of Lloviu virus as a potential new genus, Cuevavirus, within Filoviridae; and germline integrations of filovirus-like sequences in some animal species bring new insights into the relatedness of filoviruses, their prevalence and potential for transmission to humans. These new findings reveal that filoviruses are more diverse and may have had a greater influence on the evolution of animals than previously thought. Herein we review these findings with regard to the implications for understanding the host range, prevalence and transmission of Filoviridae.

Discovery of swine as a host for the Reston ebolavirus.

Since the discovery of the Marburg and Ebola species of filovirus, seemingly random, sporadic fatal outbreaks of disease in humans and nonhuman primates have given impetus to identification of host tropisms and potential reservoirs. Domestic swine in the Philippines, experiencing unusually severe outbreaks of porcine reproductive and respiratory disease syndrome, have now been discovered to host Reston ebolavirus (REBOV). Although REBOV is the only member of Filoviridae that has not been associated with disease in humans, its emergence in the human food chain is of concern. REBOV isolates were found to be more divergent from each other than from the original virus isolated in 1989, indicating polyphyletic origins and that REBOV has been circulating since, and possibly before, the initial discovery of REBOV in monkeys.

Duplication of MER115 on chromosome 4 in patients with primary biliary cirrhosis.

BACKGROUND: Primary biliary cirrhosis (PBC) is a complex disease with genetic and environmental influences. The disease is more prevalent in families with PBC and candidate gene case-control studies have linked PBC with DRB1(*)08 human leucocyte antigen class II alleles. AIMS: The goal of this study was to characterize a MER115 intergenic region on chromosome 4 as a putative genetic variant associated with PBC. METHODS/RESULTS: This region was incidentally identified during investigations to discover candidate microbial agents using representational difference analysis (RDA) with liver samples from patients with PBC and primary sclerosing cholangitis (PSC). blast search analysis of all the RDA products from the PBC liver revealed genomic sequences, whereas Escherichia coli, mycoplasma and hepatitis B virus DNA were found in the PSC liver. We identified one of the PBC RDA products as an ancestral repeat, referred to as MER115. Southern blot analysis with the PBC product uncovered a restriction fragment length polymorphism in PBC patients' liver. Southern blot hybridization signal showed increased signal intensity in PBC vs. control patients' DNA (P<0.005) and slot blot hybridization studies confirmed a copy number variation of the MER115 in hepatic DNA of PBC vs. control patients (P=0.02). CONCLUSIONS: Further comparative genetic studies will be required to determine the extent of genomic duplication associated with MER115 and provide data on the possible copy number variants of genes close to this intergenic region in patients with PBC.