Commercial Indirect Enzyme-linked Immunosorbent Assay Research Articles

Seroprevalence of Neospora caninum-specific antibodies in German breeding bitches

BackgroundNeospora caninum is an intracellular obligate apicomplexan parasite responsible for multisystemic lesions in dogs. Being definitive hosts and reservoirs, dogs excrete environmentally resistant oocysts. Breeding bitches represent a susceptible dog group and infected bitches may spread this parasite through transplacental transmission.ResultsA total of 218 serum samples of German breeding bitches were collected to determine the presence of N. caninum. Antibodies were detected in 16 (7.33%) bitches using a commercial indirect enzyme-linked immunosorbent assay (ELISA). Immunoblotting analysis confirmed all seropositive samples detected by ELISA, proving that the animals were infected with N. caninum. The owners were interviewed regarding breed, age, environment, type, vaccine status, feeding habits and the presence of reproductive disorders. Seropositive animals were between the ages of two to seven years; three of them were kept in kennels while the others were household dogs, one of which was additionally a hunting dog. Owners of four seropositive bitches reported one gestation, while multiple pregnancies had been recorded for the other twelve bitches. Fourteen bitches were regularly vaccinated and six were fed with fresh raw meat.ConclusionsAlthough the results confirmed a low incidence of N. caninum seropositive German breeding bitches, further epidemiological and surveillance studies are required to complement our findings regarding the current situation of neosporosis in this specific canine population of Germany.

Sensitivity and specificity of indirect ELISA for the detection of antibody titers against BVDV from beef cattle raised in Pará State

The aims of this study were to establish the prevalence of anti-bovine viral diarrhea virus (BVDV) antibodies (Ab) in beef cattle raised in Pará state, to compare the prevalence of seropositive animals to BVDV using a commercial indirect enzyme-linked immunosorbent assay kit (iELISA) and the virus neutralization (VN) test, and finally, to determine the sensitivity (Se) and specificity (Sp) of the iELISA for the detection of anti-BVDV Ab using VN as a gold standard. A total of 400 serum blood samples from Nelore cows aged at least 24 months from five farms in the Pará state from two mesoregions (Metropolitan Region of Belem and Northeast of Pará) were analyzed. All animals were vaccinated against brucellosis and foot-and-mouth disease. The examination of anti-BVDV Ab with VN was performed in the Laboratory of Bovine Viruses of the Biological Institute of Sao Paulo as described in the Manual of Diagnostic Tests and Vaccines for Terrestrial Animals. For VN, bovine kidney epithelial cells from the Madin Darby Bovine Kidney (MDBK) strain were used. The determinations of anti-BVDV Ab were performed with the iELISA test at the Laboratory of Immunology and Microbiology of the Federal Rural University of Amazonia according to the manufacturer's recommendations. The results were classified as follows: (a) correct positive diagnosis, (b) incorrect positive diagnosis, (c) correct negative diagnosis, and (d) incorrect negative diagnosis, according to the results obtained from VN. From the values obtained from VN and iELISA, Se [(a ÷ a + d) × 100], Sp [(c ÷ c + b) × 100], positive predictive value [(a ÷ a + B) × 100], and negative predictive value [(c ÷ c + d) × 100] were calculated for iELISA. The frequencies (%) of seropositive animals were determined and compared both between the different tests (iELISA and VN) and between the different farms (1, 2, 3, 4, and 5). The statistical analysis was performed with a significance level of 5%. The prevalence of seropositive animals was found to be different (P < 0.0001) using VN (39.25% [157/400]) and iELISA (54.50% [218/400]). It was observed that the Se and Sp of the iELISA assay were 98.72% and 74.07%, respectively. Of the total, 25.93% (63/243) of the samples were considered false-positive and 1.27% false-negative (2/157). It was concluded that the BVDV infection is present in beef cattle herds of the state of Para. Based on the speed of execution, ease of handling, and high Se of the iELISA, it is suggested that this assay can be used as a screening test for the detection of anti-BVDV Ab with the aim of eliminating infected animals from large herds of beef cattle.

Detection and genotyping of bovine leukemia virus in Mexican cattle.

Bovine leukemia virus (BLV) was detected and genotyped in a population of 201 dairy cattle from central Mexico. Using a commercial indirect enzyme-linked immunosorbent assay (iELISA) kit, 118 polymerase chain reaction (PCR)-positive and BLV antibody-positive samples were identified; the concordance between tests was substantial. A phylogenetic study of 27 partial sequences of the env gene gp30 was performed. Four mutations were detected involving the PXXP motif in the cytoplasmic domain of the transmembrane protein. This study provided evidence of the efficacy of PCR for the detection of BLV and demonstrated the presence of genotype 1 BLV in Mexico.

Prevalence of Chlamydia abortus Antibodies in Horses From the Northern State of Mexico and Its Relationship With Domestic Animals

Chlamydia abortus is obligate intracellular bacteria that cause a wide range of reproductive and respiratory diseases in animals and humans. Serologic and molecular evidences of C. abortus in Mexico have been reported in sheep and goats. The presence of C. abortus antibodies in horses (n = 301) was detected by a commercial indirect enzyme-linked immunosorbent assay test. Additionally, C. abortus antibodies in bovines (n = 25), goats (n = 8), and sheep (n = 94) reared with horses were detected to identify probable animal species that could infect horses. The prevalence obtained was 1.32% for horses, 48% for bovines, 12.5% for goats, and 29.7% for sheep. The 75% of horses seropositive to C. abortus were obtained from farms with the presence of sheep seropositive to C. abortus. These results suggest that the presence of C. abortus in horses from Mexico exist and can be related with the presence of sheep positive to C. abortus.

Seroprevalence of Toxoplasma gondii in domestic pets from metropolitan regions of Panama.

Toxoplasmosis is a worldwide zoonotic disease but information regarding domestic animals in Central America is scarce and fragmented. The aim of this study was to determine the seroprevalence of Toxoplasma gondii in domestic cats and dogs in different metropolitan regions of Panama. A total of 576 samples were collected; sera from 120 cats and 456 dogs were tested using a commercial indirect enzyme-linked immunosorbent assay (ELISA). The overall seroprevalence of IgG antibodies was 30.73%. There is high seroprevalence of T. gondii in cats and dogs in the metropolitan regions around the Panama Canal; however, differences between these species were not significant. Statistical analysis indicated that there are relevant variables, such as the age of animals, with a direct positive relationship with seroprevalence. None of the variables related to animal welfare (veterinary attention provided, type of dwelling, and access to green areas and drinking water) were associated with seropositivity.

Serological evidence of acute rubella infection among under-fives in Mwanza: a threat to increasing rates of congenital rubella syndrome in Tanzania.

BackgroundControl of rubella infection is essential for preventing congenital rubella syndrome (CRS) and one of the important steps is to define a target population for vaccination. Therefore this study was done to determine serological evidence of acute rubella infection among under-fives in order to anticipate the magnitude of rubella virus transmission in Tanzania.MethodsA cross-sectional study involving children aged between 1 and 59 months was conducted between September and October 2014 before national rubella vaccination campaigns commenced. Rubella IgM antibodies were detected using commercial indirect enzyme-linked immunosorbent assay (ELISA). Data were analyzed using STATA version 11.ResultsA total of230 under-fives were enrolled, their median age was 14 (Interquartile range (IQR) 7–26) months. The overall seroprevalence of rubella IgM antibodies was 10.9 % (25/230) with two confirmed cases of CRS. Two-sample Wilcoxon rank-sum test showed that the median age of rubella IgM seropositive children was significantly higher than that of IgM seronegative children (39 IQR: 18-51months vs. 14 IQR: 7–24 months, P < 0.001). On multivariate logistic regression analysis increase in age (OR: 1.07, 95 % CI; 1.03–1.1, P < 0.001) and residing in rural areas (OR: 8.07, 95 % CI; 1.43–45.6, P = 0.018) were independently found to predict acute rubella infection among under-fives.ConclusionOur findings indicate that rubella virus is prevalent in our setting posing a risk of transmitting to childbearing aged women hence increasing the risk of CRS. Increasing prevalence of acute infection with age in under-fives indicates the protective role of maternal antibodies among infants. The sustained vaccination programme of under-fives as effective measure to control CRS should be emphasized in developing countries.

Seroprevalence of Q Fever (Coxiellosis) in Small Ruminants of Two Districts in Punjab, Pakistan.

Coxiellosis caused by Coxiella burnetii is a cosmopolitan zoonosis, which causes significant losses through abortions and stillbirths in small ruminants. A cross-sectional seroprevalence study was conducted in two major sheep and goat farming districts of Punjab (Layyah and Muzaffargarh), Pakistan. In total, 542 small ruminants (271 sheep and goats each) of both sexes (60 males and 482 females) of different age groups from 104 flocks (52 flocks of either species) were randomly selected for the collection of sera and related epidemiological information. The sampling plan was devised at the expected prevalence of 50%, confidence interval (CI) of 95%, and error margin of 5%. A commercial indirect enzyme-linked immunosorbent assay (iELISA; ID Vet) was used to test the samples for the presence of both phase I and II antibodies. A high herd level prevalence (73.1%, 95% CI 63.5-81.3) was recorded in the studied districts. Individual level seroprevalence was recorded as 30.8% (95% CI 26.9-34.9). Higher value was recorded in females (32%) when compared with males (21.7%). Higher prevalence (34.8%, 95% CI 21.4-50.2) was observed in animals of 1 year (nulliparous) than to primiparous (24.8%, 95% CI 17.4-33.5) and multiparous (32.3%, 95% CI 27.6-37.3) animals. Univariable analysis indicated that caprine species (odds ratio [OR] 1.96, p = 0.22), females (OR = 1.70, p = 0.104), infestation with ticks (OR = 234.39, p < 0.001), abortion history (OR 1.96, p = 0.14), retention of fetal membranes (OR 1.50, p = 0.35), keeping a single breed in a herd (OR 1.50, p = 0.56), and mixed feeding management (OR 1.37, p = 0.33) were the variables found associated with high prevalence of antibodies to C. burnetii. The study indicates that seroprevalence of coxiellosis was high in the studied small ruminant population and further studies are required to discern its epidemiology more precisely.

Prevalence of antibodies to Bovine Viral Diarrhea Virus (BVDV) in blood and milk serum in dairy cattle in Kars district of Turkey

The purpose of this study was to detect of antibodies against Bovine Viral Diarrhea Virus (BVDV) in blood and milk serum samples. With this aim, a total of 192 blood and milk samples were collected from unvaccinated Holstein cows in Kars district of Turkey. Blood and milk serum samples were tested to determine the presence of antibodies against BVDV by commercial indirect enzyme-linked immunosorbent assay (ELISA). In this study, while 172 of blood serum (89.58%) were found to be positive for the presence of BVDV antibodies, 161 of milk serum samples (83.85%) were positive. In addition, 150 (78.12%) both blood and milk serum samples of same cattle were positive for BVDV antibodies. Only 22 (11.45%) blood serum of cattle was detected positive for BVDV, while only 11 (5.73%) milk serum was seropositive. Data obtained from the study showed the presence of BVDV infection in dairy herds in the Kars region and demonstrate that blood serum and milk serum samples might be consistent with one another in the determination of BVDV seroprevalence.

Seroprevalence of Mycobacterium avium subspecies paratuberculosis (MAP) and evaluation of risk factors in camels of the Sultanate of Oman.

Johne's disease (JD) is a World Animal Health Organization (OIE)-listed disease of ruminants including camels with serious economic impacts worldwide. A cross-sectional serological survey involving multistage simple random samplingwas conducted to investigate the prevalence of JD in camels of Oman. In total, 2255 camels (254 males and 2001 females) and different ages from 553 geographically marked holdings were bled for serum. The samples were analyzed by a commercial indirect enzyme-linked immunosorbent assay (ELISA) with protein 'G' as conjugate (LSI VET Ruminant Serum Paratuberculosis Advanced, France). Results indicated a widespread herd and individual level seroprevalence, respectively of 9.2% (95 % CI = 0.7-50) and 2.6%(95 % CI = 2.0-3.4)in Oman. Differences (p < 0.01) were observed regarding the prevalence of JD in sampled governorates, and the highest prevalence was recorded in Dhofar (13.5%). Higher (p > 0.05) seroprevalence was observed in females (2.8%), and their odds for testing positive were 3.69 (95% confidence interval (CI) = 0.90-15.23) times higher as compared to males (0.8%). Seropositivity increased with the age of camels, and the highest prevalence (4.4%) was observed in camels of more than 10years of age (p = 0.03). Large and medium size herds (odds ratio (OR) = 1.77, 95% CI = 0.96-3.24) where camels were kept as single species (OR = 1.54, 95% CI = 0.84-2.84) and confined (OR = 1.93, 95% CI = 1.05-3.54) were found more likely to test positive. This is the first record of seroprevalence of JD among the camels in the country which highlights their potential as an important host of the disease. The results advocate that a comprehensive control program based upon further risk analysis and molecular study should be devised in Oman.

Seroprevalence and risk factors associated with bovine viral diarrhea virus (BVDV) infection in non-vaccinated dairy and dual purpose cattle herds in Ecuador

A cross-sectional study was carried out to determine the seroprevalence and risk factors associated with Bovine viral diarrhea virus (BVDV) infection in non-vaccinated dairy and dual-purpose cattle herds from Ecuador. A total of 2,367 serum samples from 346 herds were collected from June 2008 through February 2009. A questionnaire, which included variables related to cattle, health, management measures, and the environment, was filled out in each herd. A commercial indirect enzyme-linked immunosorbent assay test was used to determine the seropositivity. A logistic regression model was used to determine risk factors at herd level. The individual seroprevalence for BVDV in non-vaccinated herds in Ecuador was 36.2% (857/2,367; CI(95%), 34.3-38.1%). The herd prevalence was 74% (256/346; CI(95%), 69.4-78.6%) and the intra-herd prevalence ranged between 11.1% and 100% (mean = 51.6%). The logistic regression model showed that the density of cattle farms in the area (more than 70%; OR, 1.94; CI(95%), 1.21-3.2) and the altitude (higher than 2,338m above sea level; 2.33; CI(95%), 1.4-3.9) are potential risk factors associated with BVDV infection.

The first report of ovine cerebral neosporosis and evaluation of Neospora caninum prevalence in sheep in New South Wales

Presence of Neospora caninum DNA was detected in the brain and spinal cord of an adult Merino sheep suspected of dying with acute non-suppurative meningoencephalitis and mild to moderate non-suppurative myelitis. The most severe neurological lesions were found in the midbrain at the rostral coliculi with moderate to severe multifocal vasculitis and gliosis. As this was the first known occurrence of cerebral disease in sheep in Australia caused by N. caninum, we surveyed sera from five sheep properties in New South Wales (NSW) to obtain information on the likely prevalence of N. caninum infection in NSW sheep flocks. Serology using a commercial indirect enzyme-linked immunosorbent assay (ELISA) revealed no N. caninum antibody-positive sheep ( n = 184). However an observed prevalence for N. caninum antibodies using a commercially available competitive ELISA was 2.2% (5/232). We conclude that although the diagnosis of fatal ovine cerebral neosporosis is of importance to our surveillance program for transmissible spongiform encephalopathy (TSE) exclusion, sheep in NSW are not commonly infected with N. caninum and this species likely plays only a minor role in the life cycle of this parasite in Australia.

Seroprevalence of Erythrovirus B19 IgG Antibody among Paediatric Patients in Makkah and Jeddah, Kingdom of Saudi Arabia

Objective: To estimate the prevalence of IgG antibodies against B19 virus (B19V) in Makkah and Jeddah, Saudi Arabia. Methods: B19V-specific IgG antibodies were detected by a commercial indirect enzyme-linked immunosorbent assay in sera of 400 paediatric patients (185 males and 215 females) aged 1–17 years. Results: Of the 400 patients, 80 (20%) had sera positive for B19V-specific IgG. The difference in the prevalence of the antibodies between genders was not statistically significant (p = 0.9). The prevalence of anti-B19V antibodies increased significantly in the age group of 12–17 years as compared to younger patients (37.5 vs. 18% in those aged 1–11 years; p = 0.006). Conclusion: This study indicated a high prevalence of IgG antibodies against B19V in paediatric patients with an increase in age.

Prevalence of Bovine Viral Diarrhoea Virus antibodies among the industrial dairy cattle herds in suburb of Mashhad-Iran

Mashhad is a major dairy production in Iran. The subject of this study was to survey the seroprevalence of Bovine Viral Diarrhea Virus (BVDV) infection using an indirect Enzyme-linked immunosorbent assay (ELISA) test in industrial dairy cattle herds in suburb of Mashhad-Iran. Totally, 141 serum samples were tested. None of the herds had been vaccinated against BVDV. Commercial indirect ELISA kit was used. The herds divided to 3 sizes as cow population. They were included: small, medium and large herds. Data were analyzed using Chi-square test. Ninety-seven (68.79%) cows were ELISA seropositive. However, the true BVDV seroprevalence was 72.25%. All of the herds were antibody positive against BVDV. The prevalence ranged from 66 to 100% within the herds. There were no significant differences between the presence of antibodies to BVDV and the herd size (P > 0.05). The prevalence in animals lower than 2 years old differed significantly with cows higher than 2 years old (P < 0.05). According to the results, it is concluded that it is likely the presence of persistently infection (PI) animal(s) within the herds in suburb of Mashhad-Iran, which is responsible for the presence antibody.

Indirect Enzyme Linked Immunosorbent Assay for Diagnosis of Brucellosis in Buffaloes

Brucellosis is an important zoonotic disease causing significant economic losses worldwide. Early detection of this disease is essential for its control and eradication. Presently, an Indirect Enzyme Linked Immunosorbent Assay (I-ELISA) was developed using lipopolysaccharide (LPS) as antigen and compared with the commercial kit using one hundred negative and positive sera each from buffaloes. The agreement for the positive result between the developed and commercial I-ELISA was 78% and for the negative it was 100%. At 52.49%, 53.09%, 53.26%, 53.86% and 53.94% cut off the sensitivity was 100%, 100%, 97.53%, 88.93% and 86.42%, while the specificity was 84.03%, 84.87%, 85.71%, 87.39% and 87.39%, respectively, for developed I-ELISA. This developed test can be used for the screening of herds as the relative sensitivity is higher.

Ralstonia solanacearum Race 3, Biovar 2 Strains Isolated from Geranium Are Pathogenic on Potato.

Ralstonia solanacearum race 3, biovar 2 is a soilborne bacterium that causes potato brown rot disease in temperate and subtropical climates. Recent outbreaks of this disease in Europe have caused serious losses, but the pathogen had not been identified in the United States. However, in 1999, strains of R. solanacearum were isolated from wilting geraniums growing in Wisconsin greenhouses. Physiological and biochemical tests of the Wisconsin strains and a similar strain from South Dakota demonstrated that the strains belong to R. solanacearum subgroup biovar 2, which is largely synonymous with the race 3 subgroup, a classification based on host range. These results were confirmed by polymerase chain reaction analyses in which race 3, biovar 2-specific primers amplified a fragment of the expected size. This is the first report of race 3, biovar 2 in the United States, and it is the first known occurrence of race 3, biovar 2 in Wiscon-sin. The geranium strains were highly pathogenic on both geranium and potato. The presence of R. solanacearum race 3, biovar 2 in the United States raises concern that the bacterium could move from ornamental plants into potato fields, where it could cause both direct economic damage and quarantine problems. A commercial indirect enzyme-linked immunosorbent assay for R. solanacearum produced some false negatives for these strains, indicating that current indexing may not be sufficient to identify this destructive pathogen.