scholarly journals Limited replication of yellow fever 17DD and 17D-Dengue recombinant viruses in rhesus monkeys

2008 ◽  
Vol 80 (2) ◽  
pp. 311-321 ◽  
Author(s):  
Gisela F. Trindade ◽  
Renato S. Marchevsky ◽  
Ana M.B. de Fillipis ◽  
Rita M.R. Nogueira ◽  
Myrna C. Bonaldo ◽  
...  
Keyword(s):  
Real Time ◽  
Yellow Fever ◽  
Rhesus Monkeys ◽  
Plaque Assay ◽  
Serum Samples ◽  
Recombinant Viruses ◽  
Peak Titer ◽  
Dengue Virus Serotypes ◽  
Polymerase Chain

For the development of safe live attenuated flavivirus vaccines one of the main properties to be established is viral replication. We have used real-time reverse transcriptase-polymerase chain reaction and virus titration by plaque assay to determine the replication of yellow fever 17DD virus (YFV 17DD) and recombinant yellow fever 17D viruses expressing envelope proteins of dengue virus serotypes 2 and 4 (17D-DENV-2 and 17D-DENV-4). Serum samples from rhesus monkeys inoculated with YFV 17DD and 17D-DENV chimeras by intracerebral or subcutaneous route were used to determine and compare the viremia induced by these viruses. Viral load quantification in samples from monkeys inoculated by either route with YFV 17DD virus suggested a restricted capability of the virus to replicate reaching not more than 2.0 log10 PFU mL-1 or 3.29 log10 copies mL-1. Recombinant 17D-dengue viruses were shown by plaquing and real-time PCR to be as attenuated as YF 17DD virus with the highest mean peak titer of 1.97 log10 PFU mL-1 or 3.53 log10 copies mL-1. These data serve as a comparative basis for the characterization of other 17D-based live attenuated candidate vaccines against other diseases.

scholarly journals Investigations, actions and learning from an outbreak of SARS-CoV-2 infection among healthcare workers in the United Kingdom

2020 ◽  
pp. 175717742097679
Author(s):  
Kordo Saeed ◽  
Emanuela Pelosi ◽  
Nitin Mahobia ◽  
Nicola White ◽  
Christopher Labdon ◽  
...  
Keyword(s):  
Real Time ◽  
Healthcare Workers ◽  
Healthcare Facility ◽  
Rt Pcr ◽  
Serum Samples ◽  
The United Kingdom ◽  
Key Issues ◽  
Current Infection ◽  
Polymerase Chain ◽  
A Current

Background: We report an outbreak of SARS coronavirus-2 (SARS-CoV-2) infection among healthcare workers (HCW) in an NHS elective healthcare facility. Methodology: A narrative chronological account of events after declaring an outbreak of SARS-CoV-2 among HCWs. As part of the investigations, HCWs were offered testing during the outbreak. These were: (1) screening by real-time reverse transcriptase polymerase chain reaction (RT- PCR) to detect a current infection; and (2) serum samples to determine seroprevalence. Results: Over 180 HCWs were tested by real-time RT-PCR for SARS-CoV-2 infection. The rate of infection was 15.2% (23.7% for clinical or directly patient-facing HCWs vs. 4.8% in non-clinical non-patient-facing HCWs). Of the infected HCWs, 57% were asymptomatic. Seroprevalence (SARS-CoV-2 IgG) among HCWs was 13%. It was challenging to establish an exact source for the outbreak. The importance of education, training, social distancing and infection prevention practices were emphasised. Additionally, avoidance of unnecessary transfer of patients and minimising cross-site working for staff and early escalation were highlighted. Establishing mass and regular screening for HCWs are also crucial to enabling the best care for patients while maintaining the wellbeing of staff. Conclusion: To our knowledge, this is the first UK outbreak report among HCWs and we hope to have highlighted some key issues and learnings that can be considered by other NHS staff and HCWs globally when dealing with such a task in future.

scholarly journals Prevalence and genetic characterization of Toxoplasma gondii in naturally infected backyard pigs intended for familial consumption in Romania

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Anamaria Ioana Paştiu ◽  
Anamaria Cozma-Petruț ◽  
Aurélien Mercier ◽  
Anamaria Balea ◽  
Lokman Galal ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Rural Areas ◽  
Antibody Test ◽  
Antibody Detection ◽  
Serum Samples ◽  
Potential Threat ◽  
Polymerase Chain ◽  
Pcr Targeting ◽  
Backyard Pigs

Abstract Background Foodborne toxoplasmosis in humans can be due to the exposure to tissue cysts of Toxoplasma gondii through the consumption of meat, including pork, of infected animals. Traditional Romanian food habits include pork as the preferred meat, while backyard pig rearing remains a common practice in many rural areas of Romania. The aims of the present study were to estimate the prevalence of T. gondii infection in naturally infected backyard pigs slaughtered for familial consumption and to genetically characterize the T. gondii strains obtained. Methods Paired blood and heart samples were collected from 94 backyard pigs, home slaughtered for private consumption. Serum samples were analyzed using the immunofluorescence antibody test (IFAT) for anti-T. gondii antibody detection. Heart samples were screened by polymerase chain reaction (PCR) targeting the 529-bp repeat region (REP529) for T. gondii detection. In addition, heart samples from IFAT positive animals were bioassayed in mice. The T. gondii isolates were genotyped by the analysis of 15 microsatellite markers. Results The results showed that almost half of the pigs investigated were T. gondii seropositive (46.8%, 95% confidence interval (CI): 36.4–57.4%) and in more than a quarter of the pigs (26.6%, 95% CI: 18.0–36.7%), the parasite was detected by PCR. Three (3/44) T. gondii strains were isolated from hearts of seropositive pigs and they all belonged to genotype II. Conclusions The present study showed the presence of T. gondii infection in backyard pigs in Romania, which suggests that consumption of pork from animals reared and slaughtered at home may pose a potential threat to human health and should be given attention. In addition, to our knowledge, this is the first study to provide data concerning T. gondii strains circulating in pigs from Romania.

scholarly journals Genotype 1 of human parvovirus B19 in clinical cases

2017 ◽  
Vol 63 (3) ◽  
pp. 224-228 ◽  
Author(s):  
Maria Isabel de Oliveira ◽  
Ana Maria Sardinha Afonso ◽  
Suely Pires Curti ◽  
Patrícia Evelin Silva ◽  
Tamyris Fernanda Barbosa ◽  
...  
Keyword(s):  
Parvovirus B19 ◽  
Infectious Agent ◽  
Immunoglobulin M ◽  
Human Parvovirus B19 ◽  
Genotype 1 ◽  
Serum Samples ◽  
Chronic Anemia ◽  
Virus Surveillance ◽  
Polymerase Chain

Summary Introduction: Virus surveillance strategies and genetic characterization of human parvovirus B19 (B19V) are important tools for regional and global control of viral outbreak. In São Paulo, Brazil, we performed a study of B19V by monitoring the spread of this virus, which is an infectious agent and could be mistakenly reported as a rash and other types of infection. Method: Serum samples were subjected to enzyme immunoassay, real time polymerase chain reaction, and sequencing. Results: From the 462 patients with suspected cases of exanthematic infections, the results of the 164 serum samples were positive for B19V immunoglobulin M. Among these cases, there were 38 patients with erythema infections and B19-associated with other infections such as encephalitis, hydrops fetalis, chronic anemia, hematological malignancies. These samples were sequenced and identified as genotype 1. Conclusion: This study showed patients with infections caused by B19V and sequencing genotype 1. Continuous monitoring is necessary to detect all known genotypes, and the emergence of new genotypes of these viruses for case management in public health control activities.

scholarly journals Characterization of Shedding Patterns of Porcine Circovirus Types 2a and 2b in Experimentally Inoculated Mature Boars

2008 ◽  
Vol 20 (6) ◽  
pp. 725-734 ◽  
Author(s):  
Darin M. Madson ◽  
Sheela Ramamoorthy ◽  
Chris Kuster ◽  
Narinder Pal ◽  
Xiang-Jin Meng ◽  
...  
Keyword(s):  
Sperm Morphology ◽  
Porcine Circovirus ◽  
Serum Samples ◽  
Treatment Groups ◽  
Swine Pathogen ◽  
Polymerase Chain ◽  
Swine Herds ◽  
Negative Controls ◽  
Group 1

Porcine circovirus-2 (PCV-2) is an economically important swine pathogen and causes PCV-associated disease (PCVAD) in pigs worldwide. Currently, 2 genotypes of PCV-2, PCV-2a and −2b, are circulating in U.S. swine herds. The objectives of the current study were to evaluate the amount of PCV-2 DNA present in semen over time, compare and correlate incidence and amount of PCV-2 present in semen samples to that present in serum samples and blood swabs, and determine if there are differences in shedding patterns between PCV-2a and −2b. Fifteen 7-month-old PCV-2-naïve Landrace boars ( Sus scrofa) were randomly allocated to 3 treatment groups. The boars in group 1 ( n = 3) served as negative controls, and those in groups 2 ( n = 6) and 3 ( n = 6) were intranasally and intramuscularly inoculated with PCV-2a and −2b, respectively. Semen, serum, and blood swab samples were collected up to 90 days postinoculation (DPI), and necropsies were performed on DPI 23,48, and 90. Larger quantities of both PCV-2a and − 2b DNA were detected earlier in serum and blood swab samples than in raw semen of experimentally inoculated boars. The incidence and duration of presence of PCV-2 DNA in semen varied among boars; however, intermittent shedding was not observed. In all sex glands, PCV-2 DNA was detected by polymerase chain reaction; however, PCV-2 antigen was not detected by immunohistochemistry, and PCV-2 had no effect on sperm morphology. Differences in shedding patterns between PCV-2a and −2b were not observed under the study conditions.

Characterization of GSTM3 polymorphism by real-time polymerase chain reaction with LightCycler

2004 ◽  
Vol 330 (1) ◽  
pp. 175-177
Author(s):  
Paola Mozzoni ◽  
Giuseppe De Palma ◽  
Eleonora Scotti ◽  
Marzia Capelletti ◽  
Antonio Mutti
Keyword(s):  
Polymerase Chain Reaction ◽  
Real Time ◽  
Chain Reaction ◽  
Polymerase Chain

Characterization of high-capacity adenovirus production by the quantitative real-time polymerase chain reaction: a comparative study of different titration methods

2008 ◽  
Vol 10 (10) ◽  
pp. 1092-1101 ◽  
Author(s):  
Julien Crettaz ◽  
Cristina Olague ◽  
Africa Vales ◽  
Igor Aurrekoetxea ◽  
Pedro Berraondo ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Comparative Study ◽  
Real Time ◽  
High Capacity ◽  
Chain Reaction ◽  
Polymerase Chain
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