scholarly journals The Comparison of Honeybee Viral Loads for Six Honeybee Viruses (ABPV, BQCV, CBPV, DWV, LSV3 and SBV) in Healthy and Clinically Affected Honeybees with TaqMan Quantitative Real-Time RT-PCR Assays

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1340
Author(s):  
Laura Šimenc ◽  
Tanja Knific ◽  
Ivan Toplak
Keyword(s):  
Viral Load ◽  
Real Time ◽  
Viral Infections ◽  
Clinical Signs ◽  
High Viral Load ◽  
Deformed Wing Virus ◽  
Viral Loads ◽  
Additional Information ◽  
Queen Cell ◽  
Paralysis Virus

The viral loads of acute bee paralysis virus (ABPV), black queen cell virus (BQCV), chronic bee paralysis virus (CBPV), deformed wing virus (DWV), Lake Sinai virus 3 (LSV3), and sacbrood bee virus (SBV) were determined in samples with the use of quantitative TaqMan real-time reverse transcription and polymerase chain reaction (RT-qPCR). A total of 108 samples of healthy adult honeybees from four differently located apiaries and samples of honeybees showing different clinical signs of viral infections from 89 apiaries were collected throughout Slovenia. The aim of this study was to discover correlations between viral loads and clinical signs in adult honeybees and confirm previously set threshold viral load levels between healthy and clinically affected honeybees. Within this study, two new RT-qPCR assays for quantification of LSV3 and SBV were developed. Statistically significant differences in viral loads of positive samples were identified between healthy and clinically affected honeybees for ABPV, CBPV, DWV, and SBV, while for BQCV and LSV3, no statistical differences were observed between both groups. Despite high detected LSV3 prevalence and viral loads around 6.00 log10 viral copies/bee, this lineage probably has a limited impact on the health status of honeybee colonies. The determined viral loads between 3.94 log10 and 13.17 log10 in positive samples for six viruses, collected over 10 consecutive months, including winter, present additional information of high viral load variations in healthy honeybee colonies.

scholarly journals Nationwide Screening for Bee Viruses and Parasites in Belgian Honey Bees

Viruses ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 890
Author(s):  
Severine Matthijs ◽  
Valérie De Waele ◽  
Valerie Vandenberge ◽  
Bénédicte Verhoeven ◽  
Jacqueline Evers ◽  
...  
Keyword(s):  
Viral Load ◽  
Real Time ◽  
Honey Bee ◽  
Honey Bees ◽  
High Viral Load ◽  
Deformed Wing Virus ◽  
Bee Health ◽  
Honey Bee Health ◽  
Varroa Mites ◽  
Paralysis Virus

The health of honey bees is threatened by multiple factors, including viruses and parasites. We screened 557 honey bee (Apis mellifera) colonies from 155 beekeepers distributed all over Belgium to determine the prevalence of seven widespread viruses and two parasites (Varroa sp. and Nosema sp.). Deformed wing virus B (DWV-B), black queen cell virus (BQCV), and sacbrood virus (SBV) were highly prevalent and detected by real-time RT-PCR in more than 95% of the colonies. Acute bee paralysis virus (ABPV), chronic bee paralysis virus (CBPV) and deformed wing virus A (DWV-A) were prevalent to a lower extent (between 18 and 29%). Most viruses were only present at low or moderate viral loads. Nevertheless, about 50% of the colonies harbored at least one virus at high viral load (>107 genome copies/bee). Varroa mites and Nosema sp. were found in 81.5% and 59.7% of the honey bee colonies, respectively, and all Nosema were identified as Nosema ceranae by real time PCR. Interestingly, we found a significant correlation between the number of Varroa mites and DWV-B viral load. To determine the combined effect of these and other factors on honey bee health in Belgium, a follow up of colonies over multiple years is necessary.

scholarly journals Virus infections of honeybees Apis Mellifera

2015 ◽  
Vol 4 (3) ◽  
Author(s):  
Giuseppina Tantillo ◽  
Marilisa Bottaro ◽  
Angela Di Pinto ◽  
Vito Martella ◽  
Pietro Di Pinto ◽  
...  
Keyword(s):  
Viral Infections ◽  
Control Strategies ◽  
Future Research ◽  
Virus Infections ◽  
Deformed Wing Virus ◽  
Starting Point ◽  
Invasive Organisms ◽  
Queen Cell ◽  
Kashmir Bee Virus ◽  
Paralysis Virus

The health and vigour of honeybee colonies are threatened by numerous parasites (such as <em>Varroa destructor</em> and <em>Nosema</em> spp.) and pathogens, including viruses, bacteria, protozoa. Among honeybee pathogens, viruses are one of the major threats to the health and wellbeing of honeybees and cause serious concern for researchers and beekeepers. To tone down the threats posed by these invasive organisms, a better understanding of bee viral infections will be of crucial importance in developing effective and environmentally benign disease control strategies. Here we summarize recent progress in the understanding of the morphology, genome organization, transmission, epidemiology and pathogenesis of eight honeybee viruses: Deformed wing virus (DWV) and Kakugo virus (KV); Sacbrood virus (SBV); Black Queen cell virus (BQCV); Acute bee paralysis virus (ABPV); Kashmir bee virus (KBV); Israeli Acute Paralysis Virus (IAPV); Chronic bee paralysis virus (CBPV). The review has been designed to provide researchers in the field with updated information about honeybee viruses and to serve as a starting point for future research.

scholarly journals Resistance of native honey bees from Rhodope Mountains and lowland regions of Bulgaria to Nosema ceranae and viral pathogens

2020 ◽  
Vol 23 (2) ◽  
pp. 206-217
Author(s):  
R. Shumkova ◽  
B. Neov ◽  
A. Georgieva ◽  
D. Teofanova ◽  
G. Radoslavov ◽  
...  
Keyword(s):  
Apis Mellifera ◽  
Honey Bee ◽  
Honey Bees ◽  
Viral Infections ◽  
Viral Pathogens ◽  
Deformed Wing Virus ◽  
Queen Cell ◽  
Kashmir Bee Virus ◽  
Paralysis Virus ◽  
Bee Viruses

The Western honey bee (Apis mellifera L., Hymenoptera: Apidae) is a species of fundamental economic, agricultural and environmental importance. The aim of this study was to compare the prevalence of some parasitic and viral pathogens in local honey bees from the Rodope Mountains and plain regions. To achieve this goal, molecular screening for two of the most distributed Nosema spp. and molecular identification of six honey bee viruses – Deformed wing virus (DWV), Acute bee paralysis virus (ABPV), Chronic bee paralysis virus (CBPV), Sacbrood virus (SBV), Kashmir bee virus (KBV), and Black queen cell virus (BQCV) was performed. Molecular analysis was carried out on 168 honey bee samples from apiaries situated in three different parts of the country where a mix of different honey bee subspecies were reared. In South Bulgaria (the Rhodope Mountains), a local honey bee called Apis mellifera rodopica (a local ecotype of A. m. macedonica) was bred, while in the other two regions (plains) different introduced subspecies existed. The results showed that the samples from the lowland regions in the country were outlined with the highest prevalence (70.5%) of N. ceranae, while those from the mountainous parts had the lowest rate (5.2%). Four of the honey bee viruses were identified – DWV (10/5.9%), followed by SBV (6/3.6%) and ABPV (2/1.2%), and one case of BQCV. In conclusion, the local honey bee A. m. rodopica (despite the higher number of samples) has shown lower prevalence of both nosemosis and viral infections. Therefore, this honey bee has to be preserved as a part of the national biodiversity.

scholarly journals Detection of Lotmaria passim, Crithidia mellificae and Replicative Forms of Deformed Wing Virus and Kashmir Bee Virus in the Small Hive Beetle (Aethina tumida)

Pathogens ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 372
Author(s):  
Antonio Nanetti ◽  
James D. Ellis ◽  
Ilaria Cardaio ◽  
Giovanni Cilia
Keyword(s):  
Honey Bee ◽  
Aethina Tumida ◽  
Small Hive Beetle ◽  
Deformed Wing Virus ◽  
Queen Cell ◽  
Kashmir Bee Virus ◽  
Acute Bee Paralysis Virus ◽  
Bee Virus ◽  
Paralysis Virus ◽  
Lotmaria Passim

Knowledge regarding the honey bee pathogens borne by invasive bee pests remains scarce. This investigation aimed to assess the presence in Aethina tumida (small hive beetle, SHB) adults of honey bee pathogens belonging to the following groups: (i) bacteria (Paenibacillus larvae and Melissococcus plutonius), (ii) trypanosomatids (Lotmaria passim and Crithidia mellificae), and (iii) viruses (black queen cell virus, Kashmir bee virus, deformed wing virus, slow paralysis virus, sacbrood virus, Israeli acute paralysis virus, acute bee paralysis virus, chronic bee paralysis virus). Specimens were collected from free-flying colonies in Gainesville (Florida, U.S.A.) in summer 2017. The results of the molecular analysis show the presence of L. passim, C. mellificae, and replicative forms of deformed wing virus (DWV) and Kashmir bee virus (KBV). Replicative forms of KBV have not previously been reported. These results support the hypothesis of pathogen spillover between managed honey bees and the SHB, and these dynamics require further investigation.

scholarly journals Performance of the Innova SARS-CoV-2 antigen rapid lateral flow test in the Liverpool asymptomatic testing pilot: population based cohort study

BMJ ◽  
2021 ◽  
pp. n1637 ◽  
Author(s):  
Marta García-Fiñana ◽  
David M Hughes ◽  
Christopher P Cheyne ◽  
Girvan Burnside ◽  
Mark Stockbridge ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Viral Load ◽  
Predictive Value ◽  
High Viral Load ◽  
Test Results ◽  
Chain Reaction ◽  
Viral Loads ◽  
Flow Test ◽  
Polymerase Chain ◽  
Lateral Flow Test

Abstract Objective To assess the performance of the SARS-CoV-2 antigen rapid lateral flow test (LFT) versus polymerase chain reaction testing in the asymptomatic general population attending testing centres. Design Observational cohort study. Setting Community LFT pilot at covid-19 testing sites in Liverpool, UK. Participants 5869 asymptomatic adults (≥18 years) voluntarily attending one of 48 testing sites during 6-29 November 2020. Interventions Participants were tested using both an Innova LFT and a quantitative reverse-transcriptase polymerase chain reaction (RT-qPCR) test based on supervised self-administered swabbing at testing sites. Main outcome measures Sensitivity, specificity, and predictive values of LFT compared with RT-qPCR in an epidemic steady state of covid-19 among adults with no classic symptoms of the disease. Results Of 5869 test results, 22 (0.4%) LFT results and 343 (5.8%) RT-qPCR results were void (that is, when the control line fails to appear within 30 minutes). Excluding the void results, the LFT versus RT-qPCR showed a sensitivity of 40.0% (95% confidence interval 28.5% to 52.4%; 28/70), specificity of 99.9% (99.8% to 99.99%; 5431/5434), positive predictive value of 90.3% (74.2% to 98.0%; 28/31), and negative predictive value of 99.2% (99.0% to 99.4%; 5431/5473). When the void samples were assumed to be negative, a sensitivity was observed for LFT of 37.8% (26.8% to 49.9%; 28/74), specificity of 99.6% (99.4% to 99.8%; 5431/5452), positive predictive value of 84.8% (68.1% to 94.9%; 28/33), and negative predictive value of 93.4% (92.7% to 94.0%; 5431/5814). The sensitivity in participants with an RT-qPCR cycle threshold (Ct) of <18.3 (approximate viral loads >10 6 RNA copies/mL) was 90.9% (58.7% to 99.8%; 10/11), a Ct of <24.4 (>10 4 RNA copies/mL) was 69.4% (51.9% to 83.7%; 25/36), and a Ct of >24.4 (<10 4 RNA copies/mL) was 9.7% (1.9% to 23.7%; 3/34). LFT is likely to detect at least three fifths and at most 998 in every 1000 people with a positive RT-qPCR test result with high viral load. Conclusions The Innova LFT can be useful for identifying infections among adults who report no symptoms of covid-19, particularly those with high viral load who are more likely to infect others. The number of asymptomatic adults with lower Ct (indicating higher viral load) missed by LFT, although small, should be considered when using single LFT in high consequence settings. Clear and accurate communication with the public about how to interpret test results is important, given the chance of missing some cases, even at high viral loads. Further research is needed to understand how infectiousness is reflected in the viral antigen shedding detected by LFT versus the viral loads approximated by RT-qPCR.

scholarly journals SARS-CoV-2 Persistence in Immunocompromised Children

2021 ◽  
Author(s):  
Susan Dolan ◽  
Jean Mulcahy Levy ◽  
Angla Moss ◽  
Kelly Pearce ◽  
Samuel Dominguez ◽  
...  
Keyword(s):  
Viral Load ◽  
Median Time ◽  
Immunosuppressive Treatment ◽  
Viral Persistence ◽  
High Viral Load ◽  
Viral Loads ◽  
Mild Disease ◽  
Kaplan Meier ◽  
Diagnostic Panel ◽  
Event Times

Introduction/Objectives: We evaluated the length of time immunocompromised children (ICC) remain positive for SARS-CoV-2, identified factors associated with viral persistence and determined cycle threshold (CT) values of children with viral persistence as a surrogate of viral load. Methods: We conducted a retrospective cohort study of ICC at a pediatric hospital from March 2020-2021. Immunocompromised status was defined as primary, secondary or acquired due to medical comorbidities/immunosuppressive treatment. The primary outcome was time to first-of-two consecutive negative SARS-CoV-2 Polymerase chain reaction (PCR) tests at least 24 hours apart. Testing of sequential clinical specimens from the same subject was conducted using the Centers for Disease Control (CDC) 2019-nCoV Real-Time RT-PCR Diagnostic Panel assay. Descriptive statistics, Kaplan-Meier curve median event times and log-rank-sum tests were used to compare outcomes between groups. Results: Ninety-one children met inclusion criteria. Median age was 15.5 years (IQR 8-18 yrs), 64% were male, 58% were white, and 43% were Hispanic/Latinx. Most (67%) were tested in outpatient settings and 58% were asymptomatic. The median time to two negative tests was 42 days (IQR 25.0,55.0), with no differences in median time by illness presentation or level of immunosuppression. Seven children had >1 sample available for repeat testing, and 5/7 (71%) children had initial CT values of <30, (moderate to high viral load); 4 children had CT values of <30 3-4 weeks later, suggesting persistent moderate to high viral loads. Conclusions: Most ICC with SARS-CoV-2 infection had mild disease, with prolonged viral persistence >6 weeks and moderate to high viral load.

scholarly journals Evaluation of saliva sampling procedures for SARS-CoV-2 diagnostics reveals differential sensitivity and association with viral load

2020 ◽  
Author(s):  
Pieter Mestdagh ◽  
Michel Gillard ◽  
Marc Arbyn ◽  
Jean-Paul Pirnay ◽  
Jeroen Poels ◽  
...  
Keyword(s):  
Viral Load ◽  
High Risk ◽  
Health Professionals ◽  
High Viral Load ◽  
Sampling Procedure ◽  
Differential Sensitivity ◽  
Collection Method ◽  
Viral Loads ◽  
Saliva Collection ◽  
Sampling Procedures

AbstractNasopharyngeal sampling has been the preferential collection method for SARS-CoV-2 diagnostics. Alternative sampling procedures that are less invasive and do not require a healthcare professional would be more preferable for patients and health professionals. Saliva collection has been proposed as such a possible alternative sampling procedure. We evaluated the sensitivity of SARS-CoV-2 testing on two different saliva collection devices (spitting versus swabbing) compared to nasopharyngeal swabs in over 2500 individuals that were either symptomatic or had high-risk contacts with infected individuals. We observed an overall poor sensitivity in saliva for SARS-CoV-2 detection (30.8% and 22.4% for spitting and swabbing, respectively). However, when focusing on individuals with medium to high viral load, sensitivity increased substantially (97.0% and 76.7% for spitting and swabbing, respectively), irrespective of symptomatic status. Our results suggest that saliva cannot readily replace nasopharyngeal sampling for SARS-CoV-2 diagnostics but may enable identification of cases with medium to high viral loads.

scholarly journals High Resolution Analysis of Respiratory Syncytial Virus Infection In Vivo

Viruses ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 926 ◽  
Author(s):  
Waleed Aljabr ◽  
Stuart Armstrong ◽  
Natasha Y. Rickett ◽  
Georgios Pollakis ◽  
Olivier Touzelet ◽  
...  
Keyword(s):  
Viral Load ◽  
Respiratory Syncytial Virus ◽  
The Elderly ◽  
High Viral Load ◽  
Label Free ◽  
Respiratory Problems ◽  
Viral Loads ◽  
High Resolution Analysis ◽  
Syncytial Virus

Human respiratory syncytial virus (HRSV) is a major cause of pediatric infection and also causes disease in the elderly and those with underlying respiratory problems. There is no vaccine for HRSV and anti-viral therapeutics are not broadly applicable. To investigate the effect of HRSV biology in children, nasopharyngeal aspirates were taken from children with different viral loads and a combined high throughput RNAseq and label free quantitative proteomics approach was used to characterize the nucleic acid and proteins in these samples. HRSV proteins were identified in the nasopharyngeal aspirates from infected children, and their abundance correlated with viral load (Ct value), confirming HRSV infection. Analysis of the HRSV genome indicated that the children were infected with sub-group A virus and that minor variants in nucleotide frequency occurred in discrete clusters along the HRSV genome, and within a patient clustered distinctly within the glycoprotein gene. Data from the samples were binned into four groups; no-HRSV infection (control), high viral load (Ct < 20), medium viral load (Ct = 20–25), and low viral load (Ct > 25). Cellular proteins associated with the anti-viral response (e.g., ISG15) were identified in the nasopharyngeal aspirates and their abundance was correlated with viral load. These combined approaches have not been used before to study HRSV biology in vivo and can be readily applied to the study the variation of virus host interactions.

scholarly journals A survey of deformed wing virus and acute bee paralysis virus in honey bee colonies from serbia using real-time RT-PCR

2014 ◽  
Vol 64 (1) ◽  
pp. 81-92 ◽  
Author(s):  
Predrag Simeunović ◽  
Jevrosima Stevanović ◽  
Dejan Vidanović ◽  
Jakov Nišavić ◽  
Dejan Radović ◽  
...  
Keyword(s):  
Real Time ◽  
Honey Bee ◽  
Sampling Location ◽  
Rt Pcr ◽  
Deformed Wing Virus ◽  
Bee Colonies ◽  
Acute Bee Paralysis Virus ◽  
Paralysis Virus ◽  
Bee Viruses

Abstract In this study 55 honey bee colonies from different Serbian regions were monitored for the presence of Deformed Wing Virus (DWV) and Acute Bee Paralysis Virus (ABPV) using TaqMan-based real-time RT-PCR assay. The results revealed the presence of DWV in each sampling location, and ABPV in 10 out of 11 apiaries. High frequency of DWV (76.4%) and ABPV (61.8%) positive samples in asymptomatic colonies can be the consequence of inefficient and postponed Varroa treatment concerning the role of this mite in the transmission and activation of honey bee viruses. The real-time RTPCR technique described in this paper is proved to be the most reliable method for this kind of investigation.

scholarly journals The Pathogen Profile of a Honey Bee Queen Does Not Reflect That of Her Workers

Insects ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 382 ◽  
Author(s):  
Jessica L. Kevill ◽  
Katie Lee ◽  
Michael Goblirsch ◽  
Erin McDermott ◽  
David R. Tarpy ◽  
...  
Keyword(s):  
Honey Bee ◽  
Horizontal Transmission ◽  
Pathogen Transmission ◽  
Black Queen Cell Virus ◽  
Deformed Wing Virus ◽  
Israeli Acute Paralysis Virus ◽  
Queen Cell ◽  
Honey Bee Queen ◽  
Acute Bee Paralysis Virus ◽  
Paralysis Virus

Throughout a honey bee queen’s lifetime, she is tended to by her worker daughters, who feed and groom her. Such interactions provide possible horizontal transmission routes for pathogens from the workers to the queen, and as such a queen’s pathogen profile may be representative of the workers within a colony. To explore this further, we investigated known honey bee pathogen co-occurrence, as well as pathogen transmission from workers to queens. Queens from 42 colonies were removed from their source hives and exchanged into a second, unrelated foster colony. Worker samples were taken from the source colony on the day of queen exchange and the queens were collected 24 days after introduction. All samples were screened for Nosema spp., Trypanosome spp., acute bee paralysis virus (ABPV), black queen cell virus (BQCV), chronic bee paralysis virus (CBPV), Israeli acute paralysis virus (IAPV), Lake Sinai virus (LSV), and deformed wing virus master variants (DWV-A, B, and C) using RT-qPCR. The data show that LSV, Nosema, and DWV-B were the most abundant pathogens in colonies. All workers (n = 42) were LSV-positive, 88% were Nosema-positive, whilst pathogen loads were low (<1 × 106 genome equivalents per pooled worker sample). All queens (n = 39) were negative for both LSV and Nosema. We found no evidence of DWV transmission occurring from worker to queen when comparing queens to foster colonies, despite DWV being present in both queens and workers. Honey bee pathogen presence and diversity in queens cannot be revealed from screening workers, nor were pathogens successfully transmitted to the queen.

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