scholarly journals A pre- and during Pandemic Survey of Sars-Cov-2 Infection in Stray Colony and Shelter Cats from a High Endemic Area of Northern Italy

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 618
Author(s):  
Eva Spada ◽  
Fabrizio Vitale ◽  
Federica Bruno ◽  
Germano Castelli ◽  
Stefano Reale ◽  
...  
Keyword(s):  
Rectal Swab ◽  
Elisa Test ◽  
Cross Reactivity ◽  
Northern Italy ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Endemic Region ◽  
Lombardy Region ◽  
Stray Cats ◽  
Stray Cat

Cats are susceptible to infection with severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2). Whilst a number of studies have been performed worldwide on owned cats, limited data are available on stray, colony or shelter cats. We investigated SARS-CoV-2 infection in a stray cat population before and during human outbreaks of SARS-CoV-2 in cities in the Lombardy region in northern Italy, a high endemic region for SARS-CoV-2, using serological and molecular methods. A cohort of different samples were collected from 241 cats, including frozen archived serum samples from 136 cats collected before the 2019 coronavirus disease (COVID-19) pandemic and serum, pharyngeal and rectal swab samples from 105 cats collected during the SARS-CoV-2 outbreak. All pre-pandemic samples tested seronegative for antibodies against the nucleocapsid of SARS-CoV-2 using indirect enzyme linked immunosorbent assay (ELISA) test, while one serum sample collected during the pandemic was seropositive. No serological cross-reactivity was detected between SARS-CoV-2 antibodies and antibodies against feline enteric (FECV) and infectious peritonitis coronavirus (FIPC), Feline Immunodeficiency Virus (FIV), Feline Calicivirus (FCV), Feline Herpesvirus-1 (FHV-1), Feline Parvovirus (FPV), Leishmania infantum, Anaplasma phagocytophilum, Rickettsia spp., Toxoplasma gondii or Chlamydophila felis. No pharyngeal or rectal swab tested positive for SARS-CoV-2 RNA on real time reverse transcription-polymerase chain reaction (rRT-PCR). Our data show that SARS-CoV-2 did infect stray cats in Lombardy during the COVID-19 pandemic, but with lower prevalence than found in owned cats. This should alleviate public concerns about stray cats acting as SARS-CoV-2 carriers.

scholarly journals Dogs as Sentinels for Flavivirus Exposure in Urban, Peri-Urban and Rural Hanoi, Vietnam

Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 507
Author(s):  
Long Pham-Thanh ◽  
Thang Nguyen-Tien ◽  
Ulf Magnusson ◽  
Vuong Bui-Nghia ◽  
Anh Bui-Ngoc ◽  
...  
Keyword(s):  
Mosquito Control ◽  
Risk Mitigation ◽  
Significant Risk ◽  
Cross Sectional Study ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Cross Sectional ◽  
Major Health ◽  
Household Level

Diseases caused by flaviviruses, including dengue fever and Japanese encephalitis, are major health problems in Vietnam. This cross-sectional study explored the feasibility of domestic dogs as sentinels to better understand risks of mosquito-borne diseases in Hanoi city. A total of 475 dogs serum samples from 221 households in six districts of Hanoi were analyzed by a competitive enzyme-linked immunosorbent assay (cELISA) for antibodies to the pr-E protein of West Nile virus and other flaviviruses due to cross-reactivity. The overall flavivirus seroprevalence in the dog population was 70.7% (95% CI = 66.4–74.8%). At the animal level, significant associations between seropositive dogs and district location, age, breed and keeping practice were determined. At the household level, the major risk factors were rural and peri-urban locations, presence of pigs, coil burning and households without mosquito-borne disease experience (p < 0.05). Mosquito control by using larvicides or electric traps could lower seropositivity, but other measures did not contribute to significant risk mitigation of flavivirus exposure in dogs. These results will support better control of mosquito-borne diseases in Hanoi, and they indicate that dogs can be used as sentinels for flavivirus exposure.

scholarly journals Prevalence of Haemoplasma Infections in Stray Cats in Northern Italy

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Eva Spada ◽  
Daniela Proverbio ◽  
Paola Galluzzo ◽  
Alessandra Della Pepa ◽  
Giada Bagnagatti De Giorgi ◽  
...  
Keyword(s):  
Risk Factors ◽  
Blood Donors ◽  
Northern Italy ◽  
Negative Association ◽  
Domestic Cats ◽  
Conventional Pcr ◽  
Blood Samples ◽  
Stray Cats ◽  
Stray Cat

This study investigated the prevalence of feline haemoplasma infections in a number of stray cat colonies in Milan, Northern Italy. Blood samples from 260 stray cats were evaluated, with conventional PCR, for the presence of DNA associated with Mycoplasma haemofelis (Mhf) and “Candidatus Mycoplasma haemominutum” (CMhm). Odd ratios (OR) were calculated to identify risk factors for haemoplasma infections. PCR was positive in 86 out of 260 subjects (33.1%), with a prevalence of 10.8% (28/260 cats) for Mhf and 22.3% (58/260 cats) for CMhm. No coinfections were registered. There were significant associations between infections and season of sampling, that is, a negative association between winter sampling and a haemoplasma positive status (OR=0.29, P=0.001), or CMhm positive status (OR=0.29, P=0.01). Haemoplasma infections are common in stray cats in Milan. Thus, domestic cats with outdoor access should be routinely monitored and treated for ectoparasites to minimize risks of disease acquisition. Moreover, as these infections are transmitted via blood, feline blood donors from this area should be screened by PCR and preferably be drawn from a population of indoor cats regularly treated for fleas.

scholarly journals Development of a Smartphone-Based Nanozyme-Linked Immunosorbent Assay for Quantitative Detection of SARS-CoV-2 Nucleocapsid Phosphoprotein in Blood

2021 ◽  
Vol 12 ◽  
Author(s):  
Bochao Liu ◽  
Ze Wu ◽  
Chaolan Liang ◽  
Jinhui Lu ◽  
Jinfeng Li ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Cross Reactivity ◽  
Quantitative Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Primary Screening ◽  
Global Pandemic ◽  
Novel Coronavirus ◽  
Acid Test ◽  
Control Samples

Since December 2019, a novel coronavirus (SARS-CoV-2) has resulted in a global pandemic of coronavirus disease (COVID-19). Although viral nucleic acid test (NAT) has been applied predominantly to detect SARS-CoV-2 RNA for confirmation diagnosis of COVID-19, an urgent need for alternative, rapid, and sensitive immunoassays is required for primary screening of virus. In this study, we developed a smartphone-based nanozyme-linked immunosorbent assay (SP-NLISA) for detecting the specific nucleocapsid phosphoprotein (NP) of SARS-CoV-2 in 37 serum samples from 20 COVID-19 patients who were diagnosed by NAT previously. By using SP-NLISA, 28/37 (75.7%) serum samples were detected for NP antigens and no cross-reactivity with blood donors’ control samples collected from different areas of China. In a control assay using the conventional enzyme-linked immunosorbent assay (ELISA), only 7/37 (18.91%) serum samples were detected for NP antigens and no cross-reactivity with control samples. SP-NLISA could be used for rapid detection of SARS-CoV-2 NP antigen in primary screening of SARS-CoV-2 infected individuals.

scholarly journals Development of a Sandwich Enzyme-Linked Immunosorbent Assay for Detection and Quantification of Clam Residues in Food Products

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Stef J. Koppelman ◽  
Ashley L. Lardizabal ◽  
Lynn Niemann ◽  
Joe L. Baumert ◽  
Steve L. Taylor
Keyword(s):  
Sandwich Elisa ◽  
Food Product ◽  
Food Products ◽  
Elisa Test ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Allergic Reactions ◽  
Arctica Islandica ◽  
Limit Of Quantification ◽  
Detection And Quantification

Seafood is a frequent cause of allergic reactions to food globally. The presence of undeclared trace amounts of clam can cause allergic reactions in sensitive individuals. Limited tools are available to test food products for the presence of traces of clam. We report on the development of a sandwich ELISA that can detect and quantify clam protein in food. Antisera against a mix of two commercially important clam species, Atlantic Surf (Spisula solidissima) and ocean quahog (Arctica islandica), were raised in rabbit and sheep. A sandwich ELISA was constructed with this antisera, and sensitivity and specificity were evaluated. Also, model food products spiked with clam protein were analyzed to assess the performance of the ELISA. Comparison was made with a commercially available ELISA for crustacea. The lower limit of quantification of the sandwich ELISA is 2.5 ppm clam protein in food samples, allowing the detection of low amounts of clam that may trigger a reaction in clam allergic patients. The sandwich ELISA was highly specific with cross-reactivity only noted for other molluscan shellfish (mussel and scallop). Clam protein in tomato juice and potato cream soup was detected well with recoveries ranging from 65 to 74% and from 74 to 113%, respectively. However when potato cream soup was retorted, the recover fell to 20%, imposing the risk of underestimating the clam content of a food product. A commercially available crustacean ELISA test was not suitable to detect clam protein. The sandwich ELISA described here is suitable for detection and quantification of clam protein in food products. Care should be taken with food products that have been retorted as the results may be underestimated.

scholarly journals Subtractive Phage Display Selection from Canine Visceral Leishmaniasis Identifies Novel Epitopes That Mimic Leishmania infantum Antigens with Potential Serodiagnosis Applications

2013 ◽  
Vol 21 (1) ◽  
pp. 96-106 ◽  
Author(s):  
Lourena E. Costa ◽  
Mayara I. S. Lima ◽  
Miguel A. Chávez-Fumagalli ◽  
Daniel Menezes-Souza ◽  
Vivian T. Martins ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Phage Display ◽  
Leishmania Infantum ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Phage Display Technology ◽  
Predictive Values ◽  
Content Type ◽  
Phage Elisa

ABSTRACTVisceral leishmaniasis (VL) is a zoonotic disease that is endemic to Brazil, where dogs are the main domestic parasite reservoirs, and the percentages of infected dogs living in regions where canine VL (CVL) is endemic have ranged from 10% to 62%. Despite technological advances, some problems have been reported with CVL serodiagnosis. The present study describes a sequential subtractive selection through phage display technology from polyclonal antibodies of negative and positive sera that resulted in the identification of potential bacteriophage-fused peptides that were highly sensitive and specific to antibodies of CVL. A negative selection was performed in which phage clones were adhered to purified IgGs from healthy andTrypanosoma cruzi-infected dogs to eliminate cross-reactive phages. The remaining supernatant nonadhered phages were submitted to positive selection against IgG from the blood serum of dogs that were infected withLeishmania infantum. Phage clones that adhered to purified IgGs from the CVL-infected serum samples were selected. Eighteen clones were identified and their reactivities tested by a phage enzyme-linked immunosorbent assay (phage-ELISA) against the serum samples from infected dogs (n= 31) compared to those from vaccinated dogs (n= 21), experimentally infected dogs with cross-reactive parasites (n= 23), and healthy controls (n= 17). Eight clones presented sensitivity, specificity, and positive and negative predictive values of 100%, and they showed no cross-reactivity withT. cruzi- orEhrlichia canis-infected dogs or with dogs vaccinated with two different commercial CVL vaccines in Brazil. Our study identified eight mimotopes ofL. infantumantigens with 100% accuracy for CVL serodiagnosis. The use of these mimotopes by phage-ELISA proved to be an excellent assay that was reproducible, simple, fast, and inexpensive, and it can be applied in CVL-monitoring programs.

scholarly journals Evaluation of the Serologic Cross-Reactivity between Transmissible Gastroenteritis Coronavirus and Porcine Respiratory Coronavirus Using Commercial Blocking Enzyme-Linked Immunosorbent Assay Kits

mSphere ◽  
2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Ronaldo Magtoto ◽  
Korakrit Poonsuk ◽  
David Baum ◽  
Jianqiang Zhang ◽  
Qi Chen ◽  
...  
Keyword(s):  
Culture Medium ◽  
Large Deletion ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Transmissible Gastroenteritis Virus ◽  
Serum Samples ◽  
Serological Tests ◽  
Transmissible Gastroenteritis ◽  
Respiratory Coronavirus ◽  
Porcine Respiratory

ABSTRACTThis study compared the performances of three commercial transmissible gastroenteritis virus/porcine respiratory coronavirus (TGEV/PRCV) blocking enzyme-linked immunosorbent assays (ELISAs) using serum samples (n = 528) collected over a 49-day observation period from pigs inoculated with TGEV strain Purdue (n = 12), TGEV strain Miller (n = 12), PRCV (n= 12), or with virus-free culture medium (n = 12). ELISA results were evaluated both with “suspect” results interpreted as positive and then as negative. All commercial kits showed excellent diagnostic specificity (99 to 100%) when testing samples from pigs inoculated with virus-free culture medium. However, analyses revealed differences between the kits in diagnostic sensitivity (percent TGEV- or PRCV-seropositive pigs), and all kits showed significant (P < 0.05) cross-reactivity between TGEV and PRCV serum antibodies, particularly during early stages of the infections. Serologic cross-reactivity between TGEV and PRCV seemed to be TGEV strain dependent, with a higher percentage of PRCV-false-positive results for pigs inoculated with TGEV Purdue than for TGEV Miller. Moreover, the overall proportion of false positives was higher when suspect results were interpreted as positive, regardless of the ELISA kit evaluated.IMPORTANCECurrent measures to prevent TGEV from entering a naive herd include quarantine and testing for TGEV-seronegative animals. However, TGEV serology is complicated due to the cross-reactivity with PRCV, which circulates subclinically in most swine herds worldwide. Conventional serological tests cannot distinguish between TGEV and PRCV antibodies; however, blocking ELISAs using antigen containing a large deletion in the amino terminus of the PRCV S protein permit differentiation of PRCV and TGEV antibodies. Several commercial TGEV/PRCV blocking ELISAs are available, but performance comparisons have not been reported in recent research. This study demonstrates that the serologic cross-reactivity between TGEV and PRCV affects the accuracy of commercial blocking ELISAs. Individual test results must be interpreted with caution, particularly in the event of suspect results. Therefore, commercial TGEV/PRCV blocking ELISAs should only be applied on a herd basis.

scholarly journals Brucellae through the food chain : the role of sheep, goats and springbok (Antidorcus marsupialis) as sources of human infections in Namibia

2011 ◽  
Vol 82 (4) ◽  
Author(s):  
K. Magwedere ◽  
A. Bishi ◽  
G. Tjipura-Zaire ◽  
G. Eberle ◽  
Y. Hemberger ◽  
...  
Keyword(s):  
Goat Milk ◽  
Raw Milk ◽  
Cross Reactivity ◽  
Control Programme ◽  
Enzyme Linked Immunosorbent Assay ◽  
Human Brucellosis ◽  
Serum Samples ◽  
Clinically Normal ◽  
Source Of Infection ◽  
Human Infections

A confirmed case of human brucellosis motivated an investigation into the potential source of infection in Namibia. Since domestic animals are principal sources of Brucella infection in humans, 1692 serum samples were screened from sheep, goats and cattle from 4 presumably at-risk farms and 900 springbok (Antidorcas marsupialis) serum samples from 29 mixed farming units for Brucella antibodies by the Rose-Bengal test (RBT) and positive cases confirmed by complement fixation test (CFT). To assess the prevalence of human brucellosis, 137 abattoir employees were tested for Brucella antibodies using the standard tube agglutination test (STAT) and by enzyme linked immunosorbent assay (ELISA). Cattle and sheep from all 4 farms were negative by RBT and CFT but 2 of the 4 farms (Ba and C) had 26/42 and 12/285 seropositive goats, respectively. Post mortem examination of seropositive goats revealed no gross pathological lesions typical of brucellosis except enlarged mesenteric and iliac lymph nodes seen in a single buck. Culture for brucellae from organs of seropositive animals was negative. None of the wildlife sera tested positive by either RBT or CFT. Interviews revealed that besides the case that prompted the investigation, a family and another person from other farms with confirmed brucellosis shared a common history of consumption of unpasteurised goat milk, home-made goat cheese and coffee with raw milk and prior contact with goats, suggesting goats as the likely source of infection. All 137 abattoir employees tested negative by STAT, but 3 were positive by ELISA. The 3 abattoir workers were clinically normal and lacked historical connections with clinical cases. Although goats are often associated with B. melitensis, these studies could not explicitly implicate this species owing to cross-reactivity with B. abortus, which can also infect goats. Nevertheless, these data reinforce the need for a better National Control Programme for brucellosis in Namibia.

scholarly journals A comparison between indirect ELISA and tuberculin skin test in the diagnosis of bovine tuberculosis in Kenya

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Daniel Muasya ◽  
George Karuoya Gitau ◽  
Thaiyah Gitau Andrew ◽  
Daniel Waweru Gakuya ◽  
John Vanleeuwen ◽  
...  
Keyword(s):  
Bovine Tuberculosis ◽  
Tuberculin Test ◽  
Elisa Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Kappa Statistics ◽  
Fisher Exact Test ◽  
Limited Information ◽  
Serum Samples ◽  
Apparent Prevalence ◽  
Kappa Agreement

Bovine tuberculosis (BTB) is an important zoonotic disease which has remained persistent in many areas of the World. Control and eradication has proved problematic due to the challenges in effective screening and diagnosis. Limited information on the status of BTB in Kenya presents a need to investigate its occurrence in cattle population. The study was carried out using an indirect antibody Enzyme Linked Immunosorbent Assay (ELISA-IDEXX-USA) to assess the agreement with Comparative Intradermal Tuberculin Test (CITT) test results between August and December 2013 in Laikipia County. The study also determined the apparent prevalence of cattle BTB antibodies in Laikipia County. A total of 276 bovine serum samples were tested using MPB70 and MPB83 recombinant proteins as capture antigens in the ELISA kit. Data were recorded in Microsoft Excel and exported to SPSS 16.0 for analysis. Apparent prevalence was calculated as a proportion at 95% CI, Kappa statistics computed, and test of significance assessed by Chi-square and Fisher exact test.  The results showed an individual animal apparent prevalence of 3.9% (11/276) and a herd prevalence of 58.3% (7/12). There was no significant association between BTB infection and both animal level factors, breed and sex. Kappa agreement test between ELISA test and TST showed a good agreement at K= 0.65. This study reported the prevalence of BTB in cattle for the first time in Laikipia County Kenya using the IDEXX ELISA. The ELISA test was comparable to the tuberculin test which is used as the gold standard for screening TB on live animals. The two tests can be used alongside for series or parallel interpretation to achieve desirable diagnostic sensitivity and specificity in disease control programs.

scholarly journals Seroprevalence and Clinical Presentation of Chikungunya Virus Infection among Febrile Outpatients Seeking Health Care in Mzuzu City, Malawi

2021 ◽  
Author(s):  
Flywell Kawonga ◽  
Gerald Misinzo ◽  
Dylo Pemba ◽  
Leonard Mboera ◽  
Isaac Thom Shawa
Keyword(s):  
Chikungunya Virus ◽  
Clinical Presentation ◽  
Age Groups ◽  
Clinical Signs ◽  
Signs And Symptoms ◽  
Viral Disease ◽  
Elisa Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Igm Antibodies

Chikungunya is a mosquito-borne viral disease caused by Chikungunya virus (CHIKV. We conducted this study determine the seroprevalence and clinical presentation of Chikungunya infection among outpatients seeking healthcare in Mzuzu City, Malawi. Blood samples were collected from malaria negative and non-septic febrile outpatients with fevers &ge;38 &deg;C, for not more than 5 days. The enzyme- linked immunosorbent assay (ELISA) test was used to detect anti-CHIKV IgM antibodies and its results were used to determine seroprevalence of Chikungunya. A total of 119 serum samples were tested, of these, 73 (61.3%) tested positive for anti-CHIKV IgM antibodies by ELISA. Laboratory requisition forms were used to capture demographic information such as age, sex, clinical signs and symptoms presented by the enrolled patients. Age groups of 1-9, 10- 19, 20- 29, 30- 39, 40- 49, and &ge;50 years had 17.8% (n= 13), 12.3 %,( n=9), 15.1%) (n=11), 19.2%; (n=14), 17.8% (n=13) and 17.8% (n=13) proportion of seroprevalence respectively. Most of the CHIKV infected individuals presented with fever (52.05%), joint pain (45.21%) and abdominal pain (42.67%). The presence of anti- CHIKV IgM antibodies suggest the presence of recent CHIKV infection and therefore accurate laboratory assays are highly recommended for CHIKV diagnosis and appropriate management of febrile patients.

scholarly journals New Resources for the Specific and Sensitive Detection of the Emerging Tomato Brown Rugose Fruit Virus

Viruses ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1680
Author(s):  
Joan Miquel Bernabé-Orts ◽  
Covadonga Torre ◽  
Eduardo Méndez-López ◽  
Yolanda Hernando ◽  
Miguel A. Aranda
Keyword(s):  
Internal Control ◽  
Plant Protection ◽  
Genetic Resistance ◽  
Diagnostic Techniques ◽  
Plant Viruses ◽  
Elisa Test ◽  
Cross Reactivity ◽  
Sensitive Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Effective Prevention

Plant viruses can evolve towards new pathogenic entities that may eventually cause outbreaks and become epidemics or even pandemics. Seven years ago, tomato brown rugose fruit virus (ToBRFV) emerged, overcoming the genetic resistance that had been employed for more than sixty years against tobamoviruses in tomato. Since then, ToBRFV has spread worldwide, producing significant losses in tomato crops. While new resistances are deployed, the only means of control is the implementation of effective prevention and eradication strategies. For this purpose, in this work, we have designed, assessed, and compared an array of tests for the specific and sensitive detection of the ToBRFV in leaf samples. First, two monoclonal antibodies were generated against a singular peptide of the ToBRFV coat protein; antibodies were utilized to devise a double-antibody-sandwich enzyme-linked immunosorbent assay (DAS-ELISA) test that sensitively detects this virus and has no cross-reactivity with other related tobamoviruses. Second, a real-time quantitative PCR (RT-qPCR) test targeting the RNA-dependent replicase open reading frame (ORF) was designed, and its performance and specificity validated in comparison with the CaTa28 and CSP1325 tests recommended by plant protection authorities in Europe. Third, in line with the tendency to use field-deployable diagnostic techniques, we developed and tested two sets of loop-mediated isothermal amplification (LAMP) primers to double-check the detection of the movement protein ORF of ToBRFV, and one set that works as an internal control. Finally, we compared all of these methods by employing a collection of samples with different ToBRFV loads to evaluate the overall performance of each test.

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