Mohamed El-Tholoth

Bio: Mohamed El-Tholoth is an academic researcher from Mansoura University. The author has contributed to research in topics: Recombinase Polymerase Amplification & Lumpy skin disease virus. The author has an hindex of 8, co-authored 27 publications receiving 397 citations. Previous affiliations of Mohamed El-Tholoth include Higher Colleges of Technology & University of Pennsylvania.

A portable reverse transcription recombinase polymerase amplification assay for rapid detection of foot-and-mouth disease virus

Abstract: Foot-and-mouth disease (FMD) is a trans-boundary viral disease of livestock, which causes huge economic losses and constitutes a serious infectious threat for livestock farming worldwide. Early diagnosis of FMD helps to diminish its impact by adequate outbreak management. In this study, we describe the development of a real-time reverse transcription recombinase polymerase amplification (RT-RPA) assay for the detection of FMD virus (FMDV). The FMDV RT-RPA design targeted the 3D gene of FMDV and a 260 nt molecular RNA standard was used for assay validation. The RT-RPA assay was fast (4–10 minutes) and the analytical sensitivity was determined at 1436 RNA molecules detected by probit regression analysis. The FMDV RT-RPA assay detected RNA prepared from all seven FMDV serotypes but did not detect classical swine fever virus or swine vesicular disease virus. The FMDV RT-RPA assay was used in the field during the recent FMD outbreak in Egypt. In clinical samples, reverse transcription polymerase chain reaction (RT-PCR) and RT-RPA showed a diagnostic sensitivity of 100% and 98%, respectively. In conclusion, FMDV RT-RPA was quicker and much easier to handle in the field than real-time RT-PCR. Thus RT-RPA could be easily implemented to perform diagnostics at quarantine stations or farms for rapid spot-of-infection detection.

Experimental infection of a US spike-insertion deletion porcine epidemic diarrhea virus in conventional nursing piglets and cross-protection to the original US PEDV infection

Abstract: Although the original US porcine epidemic diarrhea virus (PEDV) was confirmed as highly virulent by multiple studies, the virulence of spike-insertion deletion (S-INDEL) PEDV strains is undefined. In this study, 3–4 day-old conventional suckling piglets were inoculated with S-INDEL PEDV Iowa106 (4 pig litters) to study its virulence. Two litters of age-matched piglets were inoculated with either the original US PEDV PC21A or mock as positive and negative controls, respectively. Subsequently, all pigs were challenged with the original US PEDV PC21A on 21–29 days post-inoculation (dpi) to assess cross-protection. All S-INDEL Iowa106- and the original US PC21A-inoculated piglets developed diarrhea. However, the severity of clinical signs, mortality (0–75%) and fecal PEDV RNA shedding titers varied among the four S-INDEL Iowa106-inoculated litters. Compared with the original PC21A, piglets euthanized/died acutely from S-INDEL Iowa106 infection had relatively milder villous atrophy, lower antigen scores and more limited intestinal infection. Two of four S-INDEL Iowa106-infected sows and the original PC21A-infected sow showed anorexia and watery diarrhea for 1–4 days. After the original PC21A challenge, a subset (13/16) of S-INDEL Iowa106-inoculated piglets developed diarrhea, whereas all (5/5) and no (0/4) pigs in the mock and original PC21A-inoculated pigs had diarrhea, respectively. Our results suggest that the virulence of S-INDEL PEDV Iowa106 was less than the original US PEDV PC21A in suckling pigs, with 100% morbidity and 18% (6/33) overall (0–75%) mortality in suckling pigs depending on factors such as the sow’s health and lactation and the piglets’ birth weight. Prior infection by S-INDEL Iowa106 provided partial cross-protection to piglets against the original PC21A challenge at 21–29 dpi.

Determination of the infectious titer and virulence of an original US porcine epidemic diarrhea virus PC22A strain.

Abstract: The infectious dose of a virus pool of original US PEDV strain PC22A was determined in 4-day-old, cesarean-derived, colostrum-deprived (CDCD) piglets. The median pig diarrhea dose (PDD50) of the virus pool was determined as 7.35 log10 PDD50/mL, similar to the cell culture infectious titer, 7.75 log10 plaque-forming units (PFU)/mL. 100 PDD50 caused watery diarrhea in all conventional suckling piglets (n = 12) derived from a PEDV-naive sow, whereas 1000 and 10 000 PDD50 did not cause diarrhea in piglets derived from two PEDV-field exposed-recovered sows. This information is important for future PEDV challenge studies and validation of PEDV vaccines.

Recombinase polymerase amplification assay for rapid detection of lumpy skin disease virus.

Abstract: Lumpy skin disease virus (LSDV) is a Capripoxvirus infecting cattle and Buffalos. Lumpy skin disease (LSD) leads to significant economic losses due to hide damage, reduction of milk production, mastitis, infertility and mortalities (10 %). Early detection of the virus is crucial to start appropriate outbreak control measures. Veterinarians rely on the presence of the characteristic clinical signs of LSD. Laboratory diagnostics including virus isolation, sequencing and real-time polymerase chain reaction (PCR) are performed at well-equipped laboratories. In this study, a portable, simple, and rapid recombinase polymerase amplification (RPA) assay for the detection of LSDV-genome for the use on farms was developed. The LSDV RPA assay was performed at 42 °C and detected down to 179 DNA copies/reaction in a maximum of 15 min. Unspecific amplification was observed with neither LSDV-negative samples (n = 12) nor nucleic acid preparations from orf virus, bovine papular stomatitis virus, cowpoxvirus, Peste des petits ruminants and Blue tongue virus (serotypes 1, 6 and 8). The clinical sensitivity of the LSDV RPA assay matched 100 % (n = 22) to real-time PCR results. In addition, the LSDV RPA assay detected sheep and goat poxviruses. The LSDV RPA assay is a rapid and sensitive test that could be implemented in field or at quarantine stations for the identification of LSDV infected case.

G‐Protein‐Coupled Chemokine Receptor Gene in Lumpy Skin Disease Virus Isolates from Cattle and Water Buffalo (Bubalus bubalis) in Egypt

Abstract: Lumpy skin disease virus (LSDV), sheep poxvirus (SPV) and goat poxvirus (GPV) are the most serious poxviruses of ruminants. In this study, we analysed the G-protein-coupled chemokine receptor (GPCR) genes of LSDV isolates from cattle and water buffalo (Bubalus bubalis) in Egypt during the summer of 2011. Multiple alignments of the nucleotide sequences revealed that the water buffalo LSDV isolate differed from the cattle isolate at four nucleotide positions, and both isolates had nine nucleotide mutations from the reference strain, Egyptian tissue culture-adapted cattle LSDV/Ismailyia88 strain. Compared with the GPCR sequences of SPV and GPV strains, a 21 nucleotide insertion and a 12 nucleotide deletion were identified in the GPCR genes of our used isolates and other LSDVs. The amino acid sequences of GPCR genes of our isolates contained the unique signature of LSDV (A11 , T12 , T34 , S99 and P199 ). Phylogenetic analyses showed that the GPCR genes of cattle and water buffalo LSDVs were closest genetically, indicating a potential transmission of cattle LSDV to water buffalo.

Of Theory and Practice

Abstract: Much has been written about theory and practice in the law, and the tension between practitioners and theorists. Judges do not cite theoretical articles often; they rarely "apply" theories to particular cases. These arguments are not revisited. Instead the Essay explores the working and interaction of theory and practice, practitioners and theorists. The Essay starts with a story about solving a legal issue using our intellectual tools - theory, practice, and their progenies: experience and "gut." Next the Essay elaborates on the nature of theory, practice, experience and "gut." The third part of the Essay discusses theories that are helpful to practitioners and those that are less helpful. The Essay concludes that practitioners theorize, and theorists practice. They use these intellectual tools differently because the goals and orientations of theorists and practitioners, and the constraints under which they act, differ. Theory, practice, experience and "gut" help us think, remember, decide and create. They complement each other like the two sides of the same coin: distinct but inseparable.

What is Veterinary Medicine

Abstract: Transfer Requirements The following requirements for the major are subject to change without notice. To assure accuracy of the information on this sheet, you should consult with a counselor, the articulation officer, or review articulation agreements via the internet at www.assist.org Veterinary medicine uses problem-solving skills and in-depth knowledge to diagnose, treat and prevent animal diseases. It is the broadest and most comprehensive of all the health professions. The profession is concerned with enhancing the health, welfare, and productivity of animals and assuring the safety of animal products used by people. Veterinarians are highly trained medical professionals who provide for the health needs of all kinds of animals while maintaining sensitivity to human health and well-being. Most veterinarians in the United States are engaged in private practice. Other veterinarians work in a wide range of fields relating to public health, animal disease control, environmental protection, the biotechnology industry, higher education and research. Academic preparation for veterinary school takes place at the undergraduate level through a comprehensive educational experience with special emphasis in the sciences. In order to succeed academically, in the rigorous veterinary school curriculum, veterinary schools are looking for individuals with a highly developed science background. Since Pre-Veterinary is not a major, it is important to meet with a counselor during your first semester at El Camino College to help with the selection of classes. 1. Academic preparation and grade point average is critical for admission. Cumulative GPA, strong grades in science courses, and GPA in the last two years of undergraduate study are critical in the selection process. 2. Many, but not all veterinary schools require a bachelor's degree. In some instances, a bachelor's degree may make an applicant more competitive in the admission process. 3. Score on a standardized graduate admissions test (e.g. GRE, MCAT, and VCAT). Check with the individual program for the specific test required. 4. Strong letters of recommendation-Most schools require a minimum of three letters of recommendation. Some schools require on letter from a Doctor of Veterinary Medicine. 5. Undergraduate course of study-Veterinary schools are looking for both lower and upper division preparation. 6. Applicant's personal statement or narrative. 7. Extracurricular activities, work experience, community activities, motivation, individual character, personality, and other post-undergraduate experiences. 8. Animal related activities and/or animal related work experience-Most colleges are looking for a strong commitment to working with animals. Some require employment by a Veterinarian. 9. Personal interview. …

Recombinase polymerase amplification: Basics, applications and recent advances.

Abstract: Recombinase polymerase amplification (RPA) is a highly sensitive and selective isothermal amplification technique, operating at 37–42°C, with minimal sample preparation and capable of amplifying as low as 1–10 DNA target copies in less than 20 min. It has been used to amplify diverse targets, including RNA, miRNA, ssDNA and dsDNA from a wide variety of organisms and samples. An ever increasing number of publications detailing the use of RPA are appearing and amplification has been carried out in solution phase, solid phase as well as in a bridge amplification format. Furthermore, RPA has been successfully integrated with different detection strategies, from end-point lateral flow strips to real-time fluorescent detection amongst others. This review focuses on the different methodologies and advances related to RPA technology, as well as highlighting some of the advantages and drawbacks of the technique.

Recombinase Polymerase Amplification for Diagnostic Applications

Abstract: BACKGROUND: First introduced in 2006, recombinase polymerase amplification (RPA) has stirred great interest, as evidenced by 75 publications as of October 2015, with 56 of them just in the last 2 years. The widespread adoption of this isothermal molecular tool in many diagnostic fields represents an affordable (approximately 4.3 USD per test), simple (few and easy hands-on steps), fast (results within 5–20 min), and sensitive (single target copy number detected) method for the identification of pathogens and the detection of single nucleotide polymorphisms in human cancers and genetically modified organisms. CONTENT: This review summarizes the current knowledge on RPA. The molecular diagnostics of various RNA/DNA pathogens is discussed while highlighting recent applications in clinical settings with focus on point-of-care (POC) bioassays and on automated fluidic platforms. The strengths and limitations of this isothermal method are also addressed. SUMMARY: RPA is becoming a molecular tool of choice for the rapid, specific, and cost-effective identification of pathogens. Owing to minimal sample-preparation requirements, low operation temperature (25–42 °C), and commercial availability of freeze-dried reagents, this method has been applied outside laboratory settings, in remote areas, and interestingly, onboard automated sample-to-answer microfluidic devices. RPA is undoubtedly a promising isothermal molecular technique for clinical microbiology laboratories and emergence response in clinical settings.

Review: a comprehensive summary of a decade development of the recombinase polymerase amplification.

Abstract: Nucleic acid amplification has permeated every field in the life sciences since the introduction of the classic polymerase chain reaction (PCR) method in 1983. Yet, despite its fundamental reach, PCR has been constrained within the walls of a laboratory, due to its requirement for a sophisticated thermocycling machine, limiting external application in low-resource settings. New isothermal amplification strategies are seeking to break through traditional laboratory boundaries by providing nucleic acid replication at constant temperatures. Of these methods, recombinase polymerase amplification (RPA) is one of the fastest developing, experiencing rapid uptake and market, even though it was introduced comparatively late. Critically, RPA's technology potentiates highly accessible and sensitive nucleic acid amplification outside of laboratory, and even self-testing. Here we provide a comprehensive review of the equipment-free simplicity of RPA over its first decade of development. Our review includes key knowledge of RPA technology, such as its reaction components, mechanism, sensitivities and specificities, and distinctive detection methods. The review also provides know-how for developing RPA assays, and information about commercially available RPA reaction kits and accessories. We summarise critical RPA experimental tips and issues available through data mining the published literature, to assist researchers in mastering the RPA reaction. We also outline influential hotspots of RPA development, and conclude with outlooks for future development and implications for eclipsing PCR and further revolutionising the life sciences.