scholarly journals SARS-CoV-2 surveillance in Norway rats (Rattus norvegicus) from Antwerp sewer system, Belgium

2021 ◽  
Author(s):  
Valeria Carolina Colombo ◽  
Vincent Sluydts ◽  
Joachim Mariën ◽  
Bram Vanden Broecke ◽  
Natalie Van Houtte ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Serum Samples ◽  
Sewer System ◽  
Serological Tests ◽  
Tissue Samples ◽  
Norway Rat ◽  
Viral Neutralization ◽  
Human Samples ◽  
Norway Rats ◽  
Viral Neutralization Test

AbstractBackgroundSARS-CoV-2 human-to-animal transmission can lead to the establishment of novel reservoirs and the evolution of new variants with the potential to start new outbreaks in humans.AimWe tested Norway rats inhabiting the sewer system of Antwerp, Belgium, for the presence of SARS-CoV-2 following a local COVID-19 epidemic peak. In addition, we discuss the use and interpretation of SARS-CoV-2 serological tests on non-human samples.MethodsBetween November and December 2020, Norway rat oral swabs, feces and tissues from the sewer system of Antwerp were collected to be tested by RT-qPCR for the presence of SARS-CoV-2. Serum samples were screened for the presence of anti-SARS-CoV-2 IgG antibodies using a Luminex microsphere immunoassay (MIA). Samples considered positive were then checked for neutralizing antibodies using a conventional viral neutralization test (cVNT).ResultsThe serum of 35 rats was tested by MIA showing 3 potentially positive sera that were later shown to be negative by cVNT. All tissue samples of 39 rats analyzed tested negative for SARS-CoV-2 RNA.ConclusionThis is the first study that evaluates SARS-CoV-2 infection in urban rats. We can conclude that the sample of 39 rats had never been infected with SARS-CoV-2. We show that diagnostic serology tests can give misleading results when applied on non-human samples. SARS-CoV-2 monitoring activities should continue due to the emergence of new variants prone to infect Muridae rodents.

scholarly journals A rapid real-time polymerase chain reaction-based live virus microneutralization assay for detection of neutralizing antibodies against SARS-CoV-2 in blood/serum

2021 ◽  
Author(s):  
Syed Hani Abidi ◽  
Kehkeshan Imtiaz ◽  
Akbar Kanji ◽  
Shama Qaiser ◽  
Erum Khan ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Vero Cells ◽  
Neutralization Assay ◽  
Dilution Method ◽  
Rt Pcr ◽  
Serum Samples ◽  
Live Virus ◽  
Viral Neutralization ◽  
Microneutralization Assay ◽  
Infected Cells

Abstract Background Individuals recovering from COVID-19 are shown to have antibodies against the Spike and other structural proteins. Antibodies against Spike have been shown to display viral neutralization. However, not all antibodies against Spike have neutralizing ability and some may be cross-reactive. There is a need for easy-to-use SARS-CoV-2 neutralizing assays that allow the determination of virus neutralizing activity in sera of individuals. Here we describe a PCR-based micro-neutralization assay that can be used to evaluate the viral neutralization titers of serum from SARS-CoV-2 infected individuals. Methods The SARS-CoV-2 strain used was isolated from a nasopharyngeal specimen of a COVID-19 case. The limiting dilution method was used to obtain a 50% tissue culture infective dose (TCID50) of Vero cells. For the micro‐neutralization assay, 19 serum samples, with positive IgG titers against Spike receptor binding domain (RBD) were tested. After 24 hours, infected cells were inspected for the presence of the cytopathic effect, then lysed and RNA RT-PCR of SARS-CoV-2. The Ct values were used to calculate percent neutralization/inhibition of SARS-CoV-2. Results Out of 19 samples, 13 samples gave 100% neutralization at all dilutions, while 4 samples gave neutralization at lower dilution, while one sample did not give any neutralization. The correlation between RBD OD and neutralization potential was found to be statistically correlated. Conclusion We describe a rapid RT-PCR based SARS-CoV-2 microneutralization assay for detection of neutralizing antibodies. This can effectively be used to test anti-viral activity of serum antibodies for investigation of both disease-driven and vaccine-induced responses.

scholarly journals Leptospira in breast tissue and milk of urban Norway rats (Rattus norvegicus)

2016 ◽  
Vol 144 (11) ◽  
pp. 2420-2429 ◽  
Author(s):  
D. DE OLIVEIRA ◽  
C. P. FIGUEIRA ◽  
L. ZHAN ◽  
A. C. PERTILE ◽  
G. G. PEDRA ◽  
...  
Keyword(s):  
Rattus Norvegicus ◽  
Breast Tissue ◽  
Developed Countries ◽  
Immunofluorescence Assay ◽  
Health Concern ◽  
Tissue Samples ◽  
Norway Rat ◽  
First Time ◽  
Globally Distributed ◽  
Norway Rats

SUMMARYLeptospirosis is a zoonosis caused by bacteria of the genus Leptospira. The disease is globally distributed and a major public health concern. The Norway rat (Rattus norvegicus) is the main reservoir of the pathogen in urban slums of developing and developed countries. The potential routes of intra-specific leptospire transmission in rats are largely unknown. Herein, we identified pathogenic Leptospira spp. in breast tissue and milk of naturally infected rats. We examined kidney, breast tissue and milk from 24 lactating rats for the presence of leptospires using immunofluorescence, immunohistochemistry, polymerase chain reaction (PCR) and scanning electronic microscopy. All 24 rats had evidence for Leptospira in the kidneys, indicating chronic carriage. The majority of kidney-positive rats had detectable leptospires in milk (18, 75%) and breast tissue (16, 67%), as evidenced by immunofluorescence assay and immunohistochemistry. Four (17%) milk samples and two (8%) breast tissue samples were positive by quantitative real-time PCR. Scanning electron microscopy confirmed the presence of leptospires in breast tissue. No major pathological changes in breast tissue were found. This study, for the first time, identified leptospires in the milk and breast tissue of wild Norway rats, suggesting the possibility of milk-borne transmission of leptospirosis to neonates.

scholarly journals Durability of Viral Neutralization in Asymptomatic Coronavirus Disease 2019 for at Least 60 Days

2021 ◽  
Author(s):  
Amanda Haymond ◽  
Abdulla A Damluji ◽  
Aarthi Narayanan ◽  
Claudius Mueller ◽  
Alex Reeder ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Receptor Binding ◽  
Immunoglobulin G ◽  
Neutralizing Antibodies ◽  
Healthcare Workers ◽  
Binding Domain ◽  
Receptor Binding Domain ◽  
Serum Samples ◽  
Viral Neutralization ◽  
Time Period

Abstract A cohort consisting of asymptomatic healthcare workers donated temporal serum samples after infection with severe acute respiratory syndrome coronavirus 2. Analysis shows that all asymptomatic healthcare workers had neutralizing antibodies, that these antibodies persist for ≥60 days, and that anti-spike receptor-binding domain immunoglobulin G levels were correspondingly durable over the same time period.

scholarly journals A rapid real-time polymerase chain reaction-based live virus microneutralization assay for detection of neutralizing antibodies against SARS-CoV-2 in blood/serum

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0259551
Author(s):  
Syed Hani Abidi ◽  
Kehkashan Imtiaz ◽  
Akbar Kanji ◽  
Shama Qaiser ◽  
Erum Khan ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Vero Cells ◽  
Neutralization Assay ◽  
Dilution Method ◽  
Rt Pcr ◽  
Serum Samples ◽  
Live Virus ◽  
Viral Neutralization ◽  
Microneutralization Assay ◽  
Infected Cells

Background Individuals recovering from COVID-19 are known to have antibodies against the Spike and other structural proteins. Antibodies against Spike have been shown to display viral neutralization. However, not all antibodies against Spike have neutralizing ability although they may be cross-reactive. There is a need for easy-to-use SARS-CoV-2 neutralizing assays for the determination of virus-neutralizing activity in sera of individuals. Here we describe a PCR-based micro‐neutralization assay that can be used to evaluate the viral neutralization titers of serum from SARS-CoV-2 infected individuals. Methods The SARS-CoV-2 strain used was isolated from a nasopharyngeal specimen of a COVID-19 case. The limiting dilution method was used to obtain a 50% tissue culture infective dose (TCID50) of Vero cells. For the micro‐neutralization assay, 19 serum samples, with positive IgG titers against Spike Receptor-Binding Domain (RBD) were tested. After 24 hours, infected cells were inspected for the presence of a cytopathic effect, lysed and RNA RT-PCR conducted for SARS-CoV-2. PCR target Ct values were used to calculate percent neutralization/inhibition of SARS-CoV-2. Results Out of 19 samples, 13 samples gave 100% neutralization at all dilutions, 1 sample showed neutralization at the first dilution, 4 samples showed neutralization at lower dilutions, while one sample did not demonstrate any neutralization. The RBD ODs and neutralization potential percentages were found to be positively correlated. Conclusion We describe a rapid RT-PCR-based SARS-CoV-2 microneutralization assay for the detection of neutralizing antibodies. This can effectively be used to test the antiviral activity of serum antibodies for the investigation of both disease-driven and vaccine-induced responses.

scholarly journals SARS-CoV-2 neutralizing antibodies in patients with varying severity of acute COVID-19 illness

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chandima Jeewandara ◽  
Deshni Jayathilaka ◽  
Laksiri Gomes ◽  
Ananda Wijewickrama ◽  
Eranga Narangoda ◽  
...  
Keyword(s):  
Disease Severity ◽  
Neutralizing Antibodies ◽  
Vaccine Development ◽  
Neutralization Test ◽  
Severity Of Illness ◽  
Clinical Disease ◽  
Severe Illness ◽  
Plasma Therapy ◽  
Viral Neutralization ◽  
Viral Neutralization Test

AbstractIn order to support vaccine development, and to aid convalescent plasma therapy, it would be important to understand the kinetics, timing and persistence of SARS-CoV-2 neutralizing antibodies (NAbs), and their association with clinical disease severity. Therefore, we used a surrogate viral neutralization test to evaluate their levels in patients with varying severity of illness, in those with prolonged shedding and those with mild/asymptomatic illness at various time points. Patients with severe or moderate COVID-19 illness had earlier appearance of NAbs at higher levels compared to those with mild or asymptomatic illness. Furthermore, those who had prolonged shedding of the virus, had NAbs appearing faster and at higher levels than those who cleared the virus earlier. During the first week of illness the NAb levels of those with mild illness was significantly less (p = 0.01), compared to those with moderate and severe illness. At the end of 4 weeks (28 days), although 89% had NAbs, 38/76 (50%) in those with > 90 days had a negative result for the presence of NAbs. The Ab levels significantly declined during convalescence (> 90 days since onset of illness), compared to 4 to 8 weeks since onset of illness. Our data show that high levels of NAbs during early illness associated with clinical disease severity and that these antibodies declined in 50% of individuals after 3 months since onset of illness.

scholarly journals Correlation of SARS-CoV-2 Neutralizing Antibodies to an Automated Chemiluminescent Serological Immunoassay

2020 ◽  
Author(s):  
David G Grenache ◽  
Chunyan Ye ◽  
Steven B Bradfute
Keyword(s):  
Neutralizing Antibodies ◽  
Large Scale ◽  
Antibody Test ◽  
Negative Control ◽  
Standard Test ◽  
Serum Samples ◽  
Serological Tests ◽  
Signal Value ◽  
Positive Antibody ◽  
Chemiluminescent Immunoassay

Abstract Introduction Neutralizing antibodies (NAbs) are capable of binding to a virus to render it incapable of infection. The ability of commercially available SARS-CoV-2 serological tests to detect NAbs has not been widely reported. We sought to correlate the antibodies detected by an automated chemiluminescent immunoassay with NAbs. Methods Residual serum samples from 35 patients that had a positive antibody test using the LIAISON® SARS-CoV-2 S1/S2 IgG chemiluminescent immunoassay and 2 antibody-negative control sera were tested for NAbs using a plaque reduction neutralization test (PRNT). Results NAbs were detected in 66% (23/35) of the antibody-positive samples. The immunoassay signal value ranged from 21.7 to 131.3 AU/mL (median, 90.5) with significant correlation between it and the PRNT (r = 0.61, P = 0.002). In the samples without NAbs, the immunoassay signal ranged from 16.3 to 66.2 AU/mL (median, 27.2). An immunoassay signal cutoff of >41 AU/mL was 91% sensitive and 92% specific for the detection of NAbs. Discussion It is important that correlates of immunity to SARS-CoV-2 be identified and NAbs are considered to be central indicators of such. PRNT is the gold-standard test for identifying NAbs but it cannot be used for large-scale testing of populations. It is necessary to establish relationships between it and widely used commercial serological assays for SARS-CoV-2.

scholarly journals Dengue pre-vaccination screening test evaluation for the use of dengue vaccine in an endemic area

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257182
Author(s):  
Umaporn Limothai ◽  
Sasipha Tachaboon ◽  
Janejira Dinhuzen ◽  
Taweewun Hunsawong ◽  
Prapapun Ong-ajchaowlerd ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Geometric Mean ◽  
Dengue Infection ◽  
Reference Method ◽  
Elisa Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Dengue Vaccine ◽  
Serum Samples ◽  
Serological Tests ◽  
Low Sensitivity

Background The dengue vaccine (Dengvaxia) is only recommended for individuals with prior dengue infection (PDI). This study aimed to perform a serosurvey to inform decision-making for vaccine introduction and identify appropriate target populations. We also evaluated the performance of the serological tests using plaque reduction neutralization test (PRNT) as a reference test in identifying PDI to determine suitability for pre-vaccination screening. Methods We enrolled 115 healthy individuals between 10 and 22 years of age living in the Ratchaburi province of Thailand. The serum samples were tested by PRNT to measure the prevalence and concentration of serotype-specific neutralizing antibodies. The performance of the IgG rapid diagnostic test (RDT, SD Bioline, Korea) and IgG enzyme-linked immunosorbent assay (ELISA, EUROIMMUN, Germany) in identifying PDI were evaluated by using PRNT as a reference method. Results Ninety-four (81.7%) individuals neutralized one or more dengue serotypes at a titer threshold greater than or equal to 10. Multitypic profiles were observed in 70.4% of the samples which increased to 91.9% in subjects aged 19–22. Among monotypic samples, the highest proportion was reactive against DENV-1 followed by DENV-2, DENV-3, and DENV-4. The highest anti-dengue antibody titers were recorded against DENV-1 and increased with age to a geometric mean NT50 titer (GMT) of 188.6 in the 19–22 age group. While both RDT and ELISA exhibited 100% specificity, RDT demonstrated low sensitivity (35%) with ELISA displaying much greater sensitivity (87%). Conclusions Almost 80% of adolescents and youth in Ratchaburi province had already been exposed to one or more of the dengue virus serotypes. The dengue IgG RDT displayed low sensitivity and is likely not be suitable for dengue pre-vaccination screening. These results support the use of IgG ELISA test for dengue vaccination in endemic areas.

scholarly journals SARS-CoV-2 neutralizing antibodies in patients with varying severity of acute COVID-19 illness

2020 ◽  
Author(s):  
Chandima Jeewandara ◽  
Deshni Jayathilaka ◽  
Laksiri Gomes ◽  
Ananda Wijewickrama ◽  
Eranga Narangoda ◽  
...  
Keyword(s):  
Disease Severity ◽  
Neutralizing Antibodies ◽  
Vaccine Development ◽  
Neutralization Test ◽  
Severity Of Illness ◽  
Clinical Disease ◽  
Severe Illness ◽  
Plasma Therapy ◽  
Viral Neutralization ◽  
Viral Neutralization Test

Abstract In order to support vaccine development, and to aid convalescent plasma therapy, it would be important to understand the kinetics, timing and persistence of SARS-CoV2 neutralizing antibodies (NAbs), and their association with clinical disease severity. Therefore, we used a surrogate viral neutralization test to evaluate their levels in patients with varying severity of illness, in those with prolonged shedding and those with mild/asymptomatic illness at various time points.Patients with severe or moderate COVID-19 illness had earlier appearance of NAbs at higher levels compared to those with mild or asymptomatic illness. Furthermore, those who had prolonged shedding of the virus, had NAbs appearing faster and at higher levels than those who cleared the virus earlier. During the first week of illness the NAb levels of those with mild illness was significantly less (p=0.01), compared to those with moderate and severe illness. At the end of 4 weeks (28 days), although 89% had Nabs, 38/76 (50%) in those with >90 days had a negative result for the presence of NAbs. The Ab levels significantly declined during convalescence (>90 days since onset of illness), compared to 4 to 8 weeks since onset of illness. Our data show that high levels of NAbs during early illness associated with clinical disease severity and that these antibodies declined in 50% of individuals after 3 months since onset of illness.

scholarly journals Leishmania tarentolae and Leishmania infantum in humans, dogs and cats in the Pelagie archipelago, southern Italy

2021 ◽  
Vol 15 (9) ◽  
pp. e0009817
Author(s):  
Roberta Iatta ◽  
Jairo Alfonso Mendoza-Roldan ◽  
Maria Stefania Latrofa ◽  
Antonio Cascio ◽  
Emanuele Brianti ◽  
...  
Keyword(s):  
Leishmania Infantum ◽  
Molecular Diagnostic ◽  
Enzyme Linked Immunosorbent Assay ◽  
Molecular Testing ◽  
Molecular Diagnostic Techniques ◽  
Serum Samples ◽  
Serological Tests ◽  
Leishmania Tarentolae ◽  
Human Samples ◽  
Animal Populations

Visceral leishmaniasis (VL) caused by Leishmania infantum is endemic in the Mediterranean basin with most of the infected human patients remaining asymptomatic. Recently, the saurian-associated Leishmania tarentolae was detected in human blood donors and in sheltered dogs. The circulation of L. infantum and L. tarentolae was investigated in humans, dogs and cats living in the Pelagie islands (Sicily, Italy) by multiple serological and molecular testing. Human serum samples (n = 346) were tested to assess the exposure to L. infantum by immunofluorescence antibody test (IFAT), enzyme-linked immunosorbent assay (ELISA) and Western blot (WB) and to L. tarentolae by IFAT. Meanwhile, sera from dogs (n = 149) and cats (n = 32) were tested for both Leishmania species by IFAT and all blood samples by specific sets of real time-PCR for L. infantum and L. tarentolae. The agreement between serological tests performed for human samples, and between serological and molecular diagnostic techniques for both human and animal samples were also assessed. Overall, 41 human samples (11.8%, 95% CI: 8.9–15.7) were positive to L. infantum (5.2%, 95% CI: 3.3–8.1), L. tarentolae (5.2%, 95% CI: 3.3–8.1) and to both species (1.4%, 95% CI: 0.6–3.3) by serology and/or molecular tests. A good agreement among the serological tests was determined. Both Leishmania spp. were serologically and/or molecularly detected in 39.6% dogs and 43.7% cats. In addition to L. infantum, also L. tarentolae circulates in human and animal populations, raising relevant public health implications. Further studies should investigate the potential beneficial effects of L. tarentolae in the protection against L. infantum infection.

scholarly journals SARS-CoV-2 neutralizing antibodies in patients with varying severity of acute COVID-19 illness

2020 ◽  
Author(s):  
Chandima Jeewandara ◽  
Deshni Jayathilaka ◽  
Laksiri Gomes ◽  
Ananda Wijewickrama ◽  
Eranga Narangoda ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Neutralization Test ◽  
Severity Of Illness ◽  
Viral Neutralization ◽  
Time Points ◽  
Viral Neutralization Test

Abstract In order to understand the kinetics, timing and persistence of SARS-CoV2 neutralizing antibodies (Nabs) we used a surrogate viral neutralization test to evaluate their levels in patients with varying severity of illness, in those with prolonged shedding and those with mild/asymptomatic illness at various time points. Patients with severe or moderate COVID-19 illness had earlier appearance of Nabs at higher levels compared to those with mild or asymptomatic illness. Furthermore, those who had prolonged shedding of the virus, had Nabs appearing faster and at higher levels than those who cleared the virus earlier. Although all individuals appeared to be antibody positive by end of week 5, the positivity rates declined thereafter, especially in those who had mild or asymptomatic illness.

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