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Detection of myxoma virus in the classical form of myxomatosis using an AGID assay: statistical assessment of the assay’s diagnostic performance
2020
Kwit, Ewa | Osiński, Zbigniew | Lavazza, Antonio | Rzeżutka, Artur
The aim of the study was to estimate the diagnostic sensitivity (DSe) and specificity (DSp) of an agar gel immunodiffusion (AGID) assay for detection of myxoma virus (MYXV) in the classical form of myxomatosis and to compare its diagnostic performance to that of molecular methods (IAC-PCR, OIE PCR, and OIE real-time PCR). A panel of MYXV-positive samples of tissue homogenates with low (1 PCR unit – PCRU) and high (3,125 PCRU) virus levels and outbreak samples were used for method comparison studies. The validation parameters of the AGID assay were assessed using statistical methods. The AGID attained DSe of 0.65 (CI₉₅%: 0.53–0.76), DSp of 1.00 (CI₉₅%: 0.40–1.00), and accuracy of 0.67 (CI₉₅%: 0.55–0.76). The assay confirmed its diagnostic usefulness primarily for testing samples containing ≥3,125 PCRU of MYXV DNA. However, in the assaying of samples containing <3,125 PCRU of the virus there was a higher probability of getting false negative results, and only molecular methods showed a 100% sensitivity for samples with low (1 PCRU) virus concentration. The overall concordance of the results between AGID and IAC-PCR was fair (ĸ = 0.40). Full concordance of the results was observed for OIE PCR and OIE real-time PCR when control reference material was analysed. Findings from this study suggest that AGID can be used with some limitations as a screening tool for detection of MYXV infections.
Show more [+] Less [-]Comparison of a barium chloride test with ELISA for pregnancy detection in cows
2020
Dana, Omer Ismaeel | Ghaidan, Mnnat Talib | Mukhtar, Rafiq Hamakarim | Dyary, Hiewa Othman
Early detection of pregnancy is vital for appropriate reproductive management programmes to facilitate the rapid re-insemination of non-pregnant females and reduce the calving interval. A barium chloride test was compared with a commercial progesterone ELISA to detect pregnancy in non-descriptive cows and investigate if it could be applied as an alternative to ELISA in the field. Blood and urine samples were collected from 74 cows with recorded insemination dates. The progesterone ELISA and barium chloride assay were implemented to detect progesterone (P4) in blood and urine specimens, respectively. The cows' reproductive systems were examined after they were slaughtered to determine the uterus's status. Macroscopic examination of the uterus was used as a reference standard for both tests. The sensitivity rates of the P4 ELISA and barium chloride test to detect pregnant cows were 100.0% and 79.4%, and to detect the corpus luteum (CL) were 83.0% and 87.0%, respectively, their sensitivity increasing in the presence of the CL. The ELISA and barium chloride tests were 79.7% and 52.7% accurate in the diagnosis of pregnancy. The accuracy of the barium chloride test in CL detection increased to 81.0%, and that of the ELISA to 86.4%. There were no significant differences (P = 0.052) between the barium chloride assay and ELISA when they were utilised for the identification of the CL. The barium chloride test can be an inexpensive and time-saving alternative to ELISA in pregnancy diagnosis when the insemination date is known.
Show more [+] Less [-]Occurrence of gastrointestinal parasites in camels in the Tianshan Mountains pastoral area in China
2020
Guowu, Zhang | Kai, Zhang | Xifeng, Wang | Chunhui, Ji | Chengcheng, Ning | Yue, Zhao | Jun, Qiao | Qingling, Meng | Xingxing, Zhang | Kuojun, Cai | Jinsheng, Zhang | Zaichao, Zhang | Xuepeng, Cai
Gastrointestinal parasites are some of the most common pathogens which are seriously harmful to the camel’s health. The infection status of gastrointestinal parasites in camels (Camelus bactrianus) in the Tianshan Mountains pastoral area in China is still unclear. The aim of this study was to investigate the species and infection intensity of gastrointestinal tract parasites in local camels. A total of 362 fresh faecal samples were collected and examined for parasite eggs using the saturated saline floating and natural sedimentation method. The parasite eggs were subjected to morphological and molecular examination and identification, and the infection rate and mean intensity of the parasites were analysed. A total of 15 gastrointestinal tract parasite species’ eggs were identified, with a detection rate of 100%. Ostertagia spp. (100%) and Trichostrongylus spp. (98.1%) were dominant. Camels were often coinfected by 5–14 species. The average number of eggs per gram of faeces was higher for Ostertagia spp. (298), Haemonchus contortus (176) and Nematodirus spp. (138). The number of species of parasites infecting young camels was significantly lower than that of adult camels, but the infection intensity in young camels was significantly higher. Gastrointestinal parasites were highly prevalent in camels from the Tianshan Mountains pastoral area in China. This finding provides important epidemiological data for the prevention and control of associated infections in camels.
Show more [+] Less [-]Marine tetrodotoxin as a risk for human health
2019
Madejska, Anna | Michalski, Mirosław | Osek, Jacek
Tetrodotoxin (TTX) is a toxin mainly occurring naturally in contaminated puffer fish, which are a culinary delicacy in Japan. It is also detected in various marine organisms like globefish, starfish, sunfish, stars, frogs, crabs, snails, Australian blue-ringed octopuses, and bivalve molluscs. TTX is produced by marine bacteria that are consumed mainly by fish of the Tetraodontidae family and other aquatic animals. TTX poisoning through consuming marine snails has recently begun to occur over a wider geographical extent through Taiwan, China, and Europe. This neurotoxin causes food intoxication and poses an acute risk to public health. The aim of this review is to present the most recent information about TTX and its analogues with particular regard to toxicity, methods of analysis, and risk to humans of exposure.
Show more [+] Less [-]Investigation of the effects of experimental autolysis on the detection of abnormal prion protein in lymphoid and central nervous system tissues from elk and sheep by Western blotting method
2011
Huang, Hongsheng | Soutyrine, Andrei | Rendulich, Jasmine | O’Rourke, Katherine | Balachandran, Aru
Tissues unsuitable for standard immunohistochemical and histopathological examinations for chronic wasting disease (CWD) in cervids and for scrapie in sheep are frequently submitted for testing. This study investigated the effects of experimental autolysis on the detection of abnormal prion protein (PrPsc) in lymphoid and central nervous system (CNS) tissues from elk and sheep. The PrPsc was detected using a Western blotting (WB) test following PrPsc enrichment using sodium phosphotungstic acid (PTA) precipitation (PTA-WB). A commercial enzyme-linked immunosorbent assay (ELISA) was used as a reference test for quantitative measurement. This study showed that the amount of PrPsc in lymphoid and CNS tssues from elk and sheep decreased gradually as a result of autolysis, but PrPsc was still detectable after 5 and 15 d incubation at 37°C by PTA-WB for all lymphoid and CNS samples. The results of the ELISA supported those of PTA-WB, particularly for CNS tissues. In conclusion, autolysis at 37°C for 15 d would not significantly affect the detection of PrPsc in lymphoid and CNS tissues by WB and ELISA and, particularly, PTA-WB is a valuable and alternative confirmatory test to detect PrPsc in autolyzed lymphoid and CNS samples.
Show more [+] Less [-]Development of Ultra-rapid Multiplex Real-time PCR for the Detection of Genes from Avian Influenza Virus subtype H5N1
2007
Kim, E.H. (Kyonggi University, Suwon, Republic of Korea) | Lee, D.W. (Kyonggi University, Suwon, Republic of Korea) | Han, S.H. (Kyonggi University, Suwon, Republic of Korea) | Lim, Y.K. (Cheju National University, Jeju, Republic of Korea) | Yoon, B.S. (Kyonggi University, Suwon, Republic of Korea), E-mail: bsyoon@kyonggi.ac.kr
Cause of high lethality and dissemination to human being, new development of rapid method for the detection of highly pathogenic Avian Influenza Virus (AIV) is still necessary. For the detection of AIV subtype H5N1, typical pathogenic AIV, new method to confirm sub-typing of this virus is also needed. For the purpose of ultra-rapid detection and sub-typing of hemagglutinin and neuraminidase of AIV, this study was planned. As the results we could demonstrate an ultra-rapid multiplex real-time PCR (URMRT-PCR) for the detection of AIV.
Show more [+] Less [-]Development and characterization of a flow cytometric assay for detection of platelet-bound immunoglobulin G in dogs
1995
Lewis, D.C. | McVey, D.S. | Shuman, W.S. | Muller, W.B.
Objective-To develop a flow cytometric assay for detection of platelet-bound IgG in dogs. Sample Population-Negative-control platelets were obtained from 5 clinically normal Greyhounds. Positive-control platelets were platelets from 1 clinically normal dog, sensitized with dog anti-canine platelet alloantibodies. Procedure-Washed platelets were incubated with mouse anti-canine IgG conjugated to fluorescein isothiocyanate and analyzed by flow cytometry. Optimal dilution of antibody reagent and dose-response were determined, as were effects on platelet-bound IgG detection of storage time and temperature of K3EDTA-anticoagulated blood samples, variable platelet numbers, and variable filling of K3EDTA evacuated tubes. Results-A 1:128 dilution of antibody reagent was optimal. There was a linear increase in platelet-bound IgG when normal canine platelets were incubated with increasing concentrations of positive-control serum. Variable numbers of positive-control platelets tested and variable filling of K3EDTA evacuated tubes had no significant effect on platelet-bound IgG concentration. Platelet-bound IgG concentration increased with storage time at room temperature (P = 0.0003), but not when blood was kept cool. Sufficient platelets for assay were able to be isolated from 3 ml of blood from 5 dogs with < 10,000 platelets/microliter. Conclusion-This assay for platelet-bound IgG in dogs is simple, repeatable, and practical. The assay is not affected by platelet count or variable filling of evacuated tubes, and requires only 3 ml of K3EDTA-anticoagulated blood. Blood samples for testing require packaging on ice and overnight delivery but, after arrival at the laboratory, can be refrigerated and analyzed within 72 hours of collection. Clinical Relevance-Assays for platelet-bound IgG may help in assessing causes and treatment of thrombocytopenia.
Show more [+] Less [-]High-performance liquid chromatography method for determination of flunixin in bovine plasma and pharmacokinetics after single and repeated doses of the drug
1995
Odensvik, K. | Johansson, I.M.
A high-performance liquid chromatography method was developed for determination of flunixin in bovine plasma. The extraction procedure was easily performed and made it possible to detect low concentrations of flunixin with high accuracy. The limit of quantitation was 7 ng/ml (relative standard deviation = 18%, n = 10). The analytic method permits processing of 60 samples/d. Flunixin, as well as the internal standard (diclofenac sodium), belong to the group of nonsteroidal anti-inflammatory drugs, which are known to have a high degree of binding to plasma proteins. Therefore, an evaluation of several buffer systems was undertaken to optimize analytic conditions. Cattle were given 2.2 mg of flunixin meglumine/kg of body weight. In experiment 1, single injections were administered IV to q cow and IM to 1 heifer (7 days apart), and pharmacokinetic variables were calculated. The IV data were best described by a two-compartment model. The half-life after single IV or IM administration was around 4.0 hours. In experiment 2, the decreasing flunixin concentration was determined after the last of either 4 IM injections daily (n = 3 cows) or 2 IM injections daily (n = 3 cows) administered during a 14-day postpartum period. The half-life, determined between 48 and 96 hours after the last dose, was approximately 26 hours in both groups, and flunixin could be detected in plasma up to 8 days, on average. The protein binding of flunixin was studied, using the method of equilibrium dialysis. Flunixin was found to have a high degree of protein binding (ie, 99.4 +/- 0.2%) at a flunixin concentration in plasma of 3 to micrograms/ml. Differences in protein binding between cattle were not found.
Show more [+] Less [-]Detection of Toxoplasma gondii-specific IgA in the aqueous humor of cats
1995
Toxoplasma gondii-specific IgA, IgM, and IgG were measured by ELISA in the serum and aqueous humor of 29 client-owned cats with indigenous aviates and 7 specific-pathogen-free cats tested sequentially for 20 weeks after inoculation with T. gondii. Local antibody production in aqueous humor was estimated by multiplying the aqueous humor-to-serum T gondii-specific antibody ratio by the serum-to-aqueous humor total IgG (C value) or IgG (C value) ratio. Evidence for local production of antibody in aqueous humor was defined as C value greater than 8 or CTC value greater than 1. Toxoplasma gondii-specific IgM CTC values, IgG CTC values, or IgA CTC values greater than 1 were detected in the aqueous humor of 18 of 29 (62.1%) client-owned cats with endogenous uveitis; 2 cats had IgA CTC values greater than 1 without detectable IgM or IgG in aqueous humor. Toxoplasma gondii-specific IgM was not detected in the aqueous humor of experimentally inoculated cats before or after inoculation. Immunoglobulin G C values greater than 8 were detected in all 7 experimentally inoculated cats and ranged from 10.4 to 145.5. Immunoglobulin G C values greater than 8 were first detected 4 to 8 weeks after T gondii inoculation and were undetectable by week 16 after inoculation. Immunoglobulin A C values greater than 8 were detected in 4 of 7 cats and ranged from 12.7 to 264.3. Immunoglobulin A C values greater than 8 were first detected 4 to 8 weeks after inoculation, and were detected in 2 cats during week 20 after inoculation. It was concluded that some cats infected with T gondii develop detectable concentrations of T gondii-specific IgA in aqueous humor.
Show more [+] Less [-]Polymerase chain reaction for detection of Borrelia coriaceae, putative agent of epizootic bovine abortion
1994
Zingg, B.C. | LeFebvre, R.B.
The nucleotide sequence of a chromosomally encoded antigen-expressing gene of Borrelia coriaceae was determined and used as a target for the polymerase chain reaction (PCR). Two primer sets were designed specifying the amplification of 269- and 701-bp DNA fragments. Primer set I, producing the short amplicon, was tenfold more sensitive than primer set II. As little as 10 fg of purified B coriaceae DNA could consistently be detected. The PCR assays, containing controlled numbers of whole spirochetes, allowed detectable amplification of 2 to 10 organisms. An internal, nonradioactively labeled gene-specific probe verified specificity of the PCR amplicons. Neither primer set cross-reacted with other related spirochetes. This PCR assay was adapted and found suitable for identification of B. coriaceae in biological samples, such as blood and thymus. Evidence for presence of B. coriaceae in biological samples was not found in tissue samples obtained from experimentally infected cows and their fetuses. These data failed to establish a definite association between B. coriaceae and epizootic bovine abortion.
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