scholarly journals Validation of a Novel Commercial ELISA Test for the Detection of Antibodies against Coxiella burnetii

Pathogens ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1075
Author(s):  
Salvatore Ledda ◽  
Cinzia Santucciu ◽  
Valentina Chisu ◽  
Giovanna Masala

Q fever is a zoonosis caused by Coxiella burnetii, a Gram-negative pathogen with a complex life cycle and a high impact on public and animal health all over the world. The symptoms are indistinguishable from those belonging to other diseases, and the disease could be symptomless. For these reasons, reliable laboratory tests are essential for an accurate diagnosis. The aim of this study was to validate a novel enzyme-linked immunosorbent assay (ELISA) test, named the Chorus Q Fever Phase II IgG and IgM Kit (DIESSE, Diagnostica Senese S.p.A), which is performed by an instrument named Chorus, a new device in medical diagnostics. This diagnostic test is employed for the detection of antibodies against C. burnetii Phase II antigens in acute disease. Our validation protocol was performed according to the Italian Accreditation Body (ACCREDIA) (Regulation UNI CEI EN ISO/IEC 17025:2018 and 17043:2010), OIE (World Organization for Animal Health), and Statement for Reporting Studies of Diagnostic Accuracy (STARD). Operator performance was evaluated along with the analytical specificity and sensitivity (ASp and ASe) and diagnostic accuracy of the kit, with parameters such as diagnostic specificity and sensitivity (DSp and DSe) and positive and negative predictive values (PPV and NPV), in addition to the repeatability. According to the evaluated parameters, the diagnostic ELISA test was shown to be suitable for validation and commercialization as a screening method in human sera and a valid support for clinical diagnostics.

1990 ◽  
Vol 36 (4) ◽  
pp. 292-296 ◽  
Author(s):  
J. Embil ◽  
J. C. Williams ◽  
T. J. Marrie

The isotypic immune response of 16 individuals who developed Q fever pneumonia following exposure to an infected parturient cat was studied. The enzyme-linked immunosorbent (ELISA) test was used to detect IgM, IgA, and IgG antibodies to phase I and phase II Coxiella burnetii whole-cell antigens and to the phase I lipopolysaccharide. The indirect immunofluorescent antibody (IFA) test was also used to detect antibodies to phase I and phase II whole cells. None of the 16 subjects developed antibodies to the phase I lipopoly saccharide. The ELISA was more sensitive than the IFA test. IgM antibodies to phase II antigen were detectable by ELISA in 80% of the subjects at the time of onset of symptoms and were still present in 7 of the 8 tested at 32 weeks following the onset of symptoms. In all instances (ELISA: IgG, IgM; IFA: IgG, IgM) phase II antibodies developed earlier and reached higher levels than did phase I antibodies. The absence of antibodies to phase I lipopolysaccharide in acute Q fever combined with our unpublished findings of antibodies to phase I lipopoly saccharide in chronic Q fever suggests that this test may be used to distinguish acute from chronic Q fever. Key words: Q fever, immune response, ELISA.


2020 ◽  
pp. 002367722096562
Author(s):  
Laura A Galganski ◽  
Benjamin A Keller ◽  
Connor Long ◽  
Kaeli J Yamashiro ◽  
Mennatalla S Hegazi ◽  
...  

Q fever is a worldwide zoonosis caused by Coxiella burnetii that can lead to abortion, endocarditis, and death in humans. Researchers utilizing parturient domestic ruminants, including sheep, have an increased risk of occupational exposure. This study evaluated the effectiveness of our screening protocol in eliminating C. burnetii–positive sheep from our facility. From August 2010 to May 2018, all ewes ( N  =  306) and select lambs ( N  =  272; ovis aries) were screened twice for C. burnetii utilizing a serum Phase I and Phase II antibody immunofluorescence assay (IFA). The first screen was performed by the vendor prior to breeding, and the second screen was performed on arrival to the research facility. Ewes that were positive on arrival screening were quarantined and retested using repeat IFA serology, enzyme-linked immunosorbent assay, buffy coat polymerase chain reaction (PCR), and amniotic fluid PCR. The overall individual seroprevalence of C. burnetii in the flocks tested by the vendor was 14.2%. Ewes with negative Phase I and Phase II IFA results were selected for transport to the research facility. Upon arrival to the facility, two (0.7%) ewes had positive Phase I IFA results. Repeat testing demonstrated seropositivity in one of these two ewes, though amniotic fluid PCR was negative in both. The repeat seropositive ewe was euthanized prior to use in a research protocol. No Q fever was reported among husbandry, laboratory or veterinary staff during the study period. Serologic testing for C. burnetii with IFA prior to transport and following arrival to a research facility limits potential exposure to research staff.


2012 ◽  
Vol 19 (7) ◽  
pp. 1110-1115 ◽  
Author(s):  
M. C. A. Wegdam-Blans ◽  
C. C. H. Wielders ◽  
J. Meekelenkamp ◽  
J. M. Korbeeck ◽  
T. Herremans ◽  
...  

ABSTRACTIn this study, we comparedCoxiella burnetiiIgG phase I, IgG phase II, and IgM phase II detection among a commercially available enzyme-linked immunosorbent assay (ELISA) (Virion/Serion), an indirect fluorescent antibody test (IFAT) (Focus Diagnostics), and a complement fixation test (CFT) (Virion/Serion). For this, we used a unique collection of acute- and convalescent-phase sera from 126 patients with acute Q fever diagnosed by positiveCoxiella burnetiiPCR of blood. We were able to establish a reliable date of onset of disease, since DNA is detectable within 2 weeks after the start of symptoms. In acute samples, att= 0, IFAT demonstrated IgM phase II antibodies in significantly more sera than did ELISA (31.8% versus 19.7%), although the portion of solitary IgM phase II was equal for IFAT and for ELISA (18.2% and 16.7%, respectively). Twelve months after the diagnosis of acute Q fever, 83.5% and 62.2% of the sera were still positive for IgM phase II with IFAT and ELISA, respectively. At 12 months IFAT IgG phase II showed the slowest decline. Therefore, definitive serological evidence of acute Q fever cannot be based on a single serum sample in areas of epidemicity and should involve measurement of both IgM and IgG antibodies in paired serum. Based on IgG phase II antibody detection in paired samples (at 0 and 3 months) from 62 patients, IFAT confirmed more cases than ELISA and CFT, but the differences were not statically significant (100% for IFAT, 95.2% for ELISA, and 96.8% for CFT). This study demonstrated that the three serological tests are equally effective in diagnosing acute Q fever within 3 months of start of symptoms. In follow-up sera, more IgG antibodies were detected by IFAT than by ELISA or CFT, making IFAT more suitable for prevaccination screening programs.


Author(s):  
Shuaibu Gidado Adamu ◽  
Junaidu Kabir ◽  
Jarlath Udo Umoh ◽  
Mashood Abiola Raji

Abstract A cross-sectional study was carried out to determine the seroprevalence and risk factors of Q fever in sheep in the northern part of Kaduna State, Nigeria. This study aimed to determine Coxiella burnetii infection and its risk factors in sheep in Kaduna State. A total of 400 blood samples consisting of 259 samples from females and 141 from males were aseptically collected from the jugular vein of sheep from flocks in Kaduna State. The sera obtained were screened for Q fever using an indirect enzyme-linked immunosorbent assay (iELISA). The obtained data were analysed to determine whether there is a relationship between sex, age, and the animals tested. The analysis revealed that 8.0% of the sera was seropositive by iELISA. There was no significant difference in Q fever seropositivity in the study area according to the sex of sheep (P > 0.05). There was a statistically significant difference (P < 0.05) in Q fever seropositivity according to the age of sheep. This study indicated a high seroprevalence of Q fever mainly among female animals and older sheep. Further studies are required to determine the epizootiology of Q fever in the study area more precisely.


2001 ◽  
Vol 46 (No. 2) ◽  
pp. 29-34 ◽  
Author(s):  
K. Kovařčík

We developed an indirect enzyme-linked immunosorbent assay (ELISA) for detection of serum antibodies to bovine respiratory syncytial virus. For evaluation of the newly developed ELISA, field sera collected from 549 head of cattle in the Czech Republic were tested in parallel by a serum neutralization test. The tests showed 98.36% agreement. The specificity and sensitivity of the ELISA relative to serum neutralization test was 97.00% (226/233) and 99.37% (314/316), respectively. Tissue culture-grown viral antigen was used in the tests. The corrected optical density (COD) of each sample tested at dilution 1/100 was expressed as a percentage of the COD of a positive reference serum included on each plate, this value was the sample/positive (S/P) ratio. We determined the relationship between the S/P ratio (%) obtained at a dilution 1/100 and the end point titer calculated by serum neutralization test (r = 0.9743). The ELISA test was evaluated by testing acute and convalescent (3 wk later) serum pairs from 9 head of cattle with confirmed BRSV infection for demonstration of seroconversion. The ELISA test demonstrated a clear increase of the S/P ratio (%) between acute and convalescent serum pairs (on average 42.2 &plusmn; 13.1).


2020 ◽  
Vol 8 (8) ◽  
pp. 1235 ◽  
Author(s):  
Mareike Stellfeld ◽  
Claudia Gerlach ◽  
Ina-Gabriele Richter ◽  
Peter Miethe ◽  
Dominika Fahlbusch ◽  
...  

Coxiella burnetii is the causative agent of Q fever, a zoonosis infecting domestic ruminants and humans. Currently used routine diagnostic tools offer limited sensitivity and specificity and symptomless infected animals may be missed. Therefore, diagnostic tools of higher sensitivity and specificity must be developed. For this purpose, the C. burnetii outer membrane protein Com1 was cloned and expressed in Escherichia coli. The His-tagged recombinant protein was purified and used in an indirect enzyme-linked immunosorbent assay (ELISA). Assay performance was tested with more than 400 positive and negative sera from sheep, goats and cattle from 36 locations. Calculation of sensitivity and specificity was undertaken using receiver operating characteristic (ROC) curves. The sensitivities and specificities for sheep were 85% and 68% (optical density at 450nm, OD450 cut-off value 0.32), for goats 94% and 77% (OD450 cut-off value 0.23) and for cattle 71% and 70% (OD450 cut-off value 0.18), respectively. These results correspond to excellent, outstanding and acceptable discrimination of positive and negative sera. In summary, recombinant Com1 can provide a basis for more sensitive and specific diagnostic tools in veterinary medicine.


Author(s):  
Ayse Kilic ◽  
Hakan Kalender

Q fever is a zoonotic disease that occurs worldwide and is caused by the obligate intracellular bacterium Coxiella burnetii. Infected animals are usually asymptomatic, but infection can cause abortion and stillbirth in ruminants. The main purpose of this study was to evaluate prevalance of Coxiella burnetii infection in aborted and nonaborted sheep serum samples in Eastern Anatolia region by using enzyme-linked immunosorbent assay (ELISA). The determine of prevalance in sheep flocks from four provinces (Elazig, Malatya, Tunceli, Bitlis) and tested for anti-C.burnetii antibody detection, by means of Chekit Q fever Elisa kit. 350 serum samples obtained from flocks belonging aborted sheep showed that a total of 56 (16%) were detected seropositivity, whereas 171 serum samples obtained from nonaborted sheep flocks in 13 of the 171 (7.60%) for C.burnetii in seropositivity were observed. Coxiellosis should be considered an important cause of sheep with abortion history and nonaborted in Elazig and neighboring provinces.


Author(s):  
Pilar Foronda ◽  
Josué Plata-Luis ◽  
Borja Del Castillo-Figueruelo ◽  
Ángela Fernández-Álvarez ◽  
Aarón Martín-Alonso ◽  
...  

Coxiella burnetii and Toxoplasma gondii are intracellular parasites that cause important reproductive disorders in animals and humans worldwide, resulting in high economic losses. The aim of the present study was to analyse the possible role of peridomestic small mammals in the maintenance and transmission of C. burnetii and T. gondii in the north-western African archipelagos of the Canary Islands and Cape Verde, where these species are commonly found affecting humans and farm animals. Between 2009 and 2013, 108 black rats (Rattus rattus) and 77 mice (Mus musculus) were analysed for the presence of Coxiella and Toxoplasma antibodies by enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence (IFA), respectively. Our results showed a wide distribution of C. burnetii and T. gondii, except for T. gondii in Cape Verde, in both rodent species. The overall seroprevalence of C. burnetii antibodies was 12.4%; 21.1% for Cape Verde and 10.2% for the Canary Islands. With respect to T. gondii, seropositive rodents were only observed in the Canary Islands, with an overall seroprevalence of 15%. Considering the fact that both pathogens can infect a large range of hosts, including livestock and humans, the results are of public health and veterinary importance and could be used by governmental entities to manage risk factors and to prevent future cases of Q fever and toxoplasmosis.


1996 ◽  
Vol 7 (1) ◽  
pp. 45-48
Author(s):  
TJ Marrie ◽  
Linda Yates

Western immunoblotting was used to compare the immune response toCoxiella burnetiiphase I and phase II antigens of humans with acute and chronic Q fever with that of infected cats, rabbits, cows and raccoons. The cats, rabbits, cows and raccoons had an immunoblot profile similar to that of the human with chronic Q fever.


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