Seroprevalence of Streptococcus suis in Tibetan pigs in Tibet, China

Author(s):  
AYanfang LAN ◽  
B Peng SHANG ◽  
Jiakui LI ◽  
Yangzom CHAMBA

To investigate the seroprevalence of Streptococcus suis (S. suis) in Tibetan Pigs on Tibetan plateau of China, a total of 454 serum samples were collected from December 2014 to January 2015 and analyzed by enzyme linked immunosorbent assay (ELISA) for Streptococcus antibodies. The seroprevalence was found to be 61.79% (95% CI 55.4-67.9), 57.81% (95% CI 50.5-64.9) and 62.50% (95% CI 35.4-84.8) in Tibetan counties of Nyingchi, Mainling and Gongbo'gvamda respectively; and 61.34% (95% CI 54.1-68.2) of females and 59.23 % (95% CI 53.0-65.3) of males were found to be positive for S. suis. These findings suggested a high seroprevalence of S. suis in Tibet pigs triggering a public concern.

Author(s):  
A. Ertürk ◽  
S. G. Cizmeci ◽  
M. F. Barut ◽  
Alberto Allepuz ◽  
Anna Alba ◽  
...  

The objective of this study was to detect the presence of new serotypes of bluetongue (BT) circulating in Turkey. A cross-sec­tional study was conducted between March and May 2008 in the provinces of Adana, Mersin, Antalya, Osmaniye, and Hatay (Mediterranean region). The serosurvey was only performed in cattle. This species was not vaccinated and the presence of an­tibodies would indicate that the animal had been infected by field strains of BT virus. Only animals born after the outbreaks were sampled. The epidemiological unit was the village, which was the lowest level for which census data was available. Ran­dom sampling was carried out in 146 villages and eight sam­ples were collected in each village.  A competitive enzyme-linked immunosorbent assay (cELISA) was used for detection of BT antibodies. Preliminary results of the study were presented. From a total of 1096 serum samples collected, 352 (32.1%) were positive to BT. The seroprevalence by province ranged from 15% in Antalya (45/257) to 88% in Osmaniye (77/88). In animals under two years old, the sero­prevalence was 25%, whereas in adult animals it was 52%. The differences in the seroprevalence detected between the five provinces could be attributed to the different density of vector, cattle and small ruminant populations. The high seroprevalence in unvaccinated cattle indicated that BT infection was wide­spread in the ruminant population of Turkey. The young animals presented a lower prevalence than the adults, suggesting that the adults had probably been exposed to the virus before the last two years, whereas the presence of positive seroconversion in young animals indicated that BT virus had been circulating in the two-year period.


2008 ◽  
Vol 15 (12) ◽  
pp. 1839-1844 ◽  
Author(s):  
Maged H. Gomaa ◽  
Dongwan Yoo ◽  
Davor Ojkic ◽  
John R. Barta

ABSTRACT Turkey coronavirus (TCoV) causes diarrhea in young turkey poults, but little is known about its prevalence in the field. To address this, the complete nucleocapsid gene was cloned and expressed in Escherichia coli. Expressed nucleocapsid gene produced two distinct proteins (52 and 43 kDa); their specificity was confirmed by Western blotting using two different monoclonal antibodies. Recombinant N protein was purified and used as an antigen to develop an enzyme-linked immunosorbent assay (ELISA) for the serological detection of TCoV that was then validated using experimentally derived turkey serum. The N-based ELISA showed (97%) sensitivity and (93%) specificity for TCoV, which was significantly higher than an infectious bronchitis coronavirus-based commercial test for TCoV. To assess the utility of this recombinant ELISA, 360 serum samples from turkey farms in Ontario, Canada, and 81 serum samples from farms in Arkansas were tested for TCoV-specific antibodies. A high seroprevalence of TCoV was found in turkeys from the Ontario farms with 73.9% of breeders and 60.0% of meat turkeys testing seropositive using the N-based ELISA. Similarly, a high field prevalence was found in the turkeys from Arkansas, for which 64.2% of the serum samples tested seropositive.


2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Getachew Gari ◽  
Biressaw Serda ◽  
Dejene Negesa ◽  
Fethu Lemma ◽  
Hagos Asgedom

Peste des petits ruminant (PPR) is an economically important disease of small ruminants with a rapidly expanding geographical distribution. There are fragmented reports to the occurrence and distribution of the disease in Ethiopia. A total of 700 serum samples were collected from goats and sheep to detect the presence of antibody against PPR virus using Competitive Enzyme-Linked Immunosorbent Assay (C-ELISA). An overall PPR seropositivity was reported to be 48.43% in the area. There is no statistically significant difference in the seroprevalence of the disease between sheep and goats (50.85% and 46.68%), respectively. However, there was statistically significant variation (P<0.05) in the seroprevalence of the disease in young (33.9%) and adult (55.8%) age categories. The seroprevalence in male and female was 42.07% and 50.09%, respectively, where the variation was statistically not significant (P>0.05). High seroprevalence of Peste des petites ruminants in the study area indicated the virus circulation and endemicity of the disease. The disease causes substantial economic losses by affecting the livelihood of the farmers. Therefore, control measures should be put in place to minimize the loss associated with the disease.


2009 ◽  
Vol 11 (10) ◽  
pp. 881-884 ◽  
Author(s):  
Annamaria Pratelli ◽  
Kadir Yesilbag ◽  
Marcello Siniscalchi ◽  
Ebru Yalçm ◽  
Zeki Yilmaz

Feline sera from Bursa province (Turkey) were assayed for coronavirus antibody using an enzyme-linked immunosorbent assay (ELISA). The study was performed on 100 sera collected from cats belonging to catteries or community shelters and to households. The serum samples were initially tested with the virus neutralisation (VN) test and the results were then compared with the ELISA. The VN yielded 79 negative and 21 positive sera but the ELISA confirmed only 74 as negative. The ELISA-negative sera were also found to be free of feline coronoviruses-specific antibodies by Western blotting. Using the VN as the gold standard test, ELISA had a sensitivity of 100% and a specificity of 93.6%, with an overall agreement of 95%. The Kappa (κ) test indicated high association between the two tests (κ=0.86, 95% confidence interval (CI) 0.743–0.980). The positive predictive value (PPV) was 0.8, and the negative predictive value (NPV) was 0.93. The prevalence of FCoV II antibodies in the sampled population based on the gold standard was 62% (95% CI 0.44–0.77) among multi-cat environments, and 4% (95% CI 0.01–0.11) among single cat households.


2000 ◽  
Vol 12 (2) ◽  
pp. 142-145 ◽  
Author(s):  
James O. Mecham ◽  
Michael M. Jochim

An enzyme-linked immunosorbent assay has been developed to detect antibodies to epizootic hemorrhagic disease of deer virus (EHDV). The assay incorporates a monoclonal antibody to EHDV serotype 2 (EHDV-2) that demonstrates specificity for the viral structural protein, VP7. The assay was evaluated with sequential sera collected from cattle experimentally infected with EHDV serotype 1 (EHDV-1) and EHDV-2, as well as the four serotypes of bluetongue virus (BTV), BTV-10, BTV-11, BTV-13, and BTV-17, that currently circulate in the US. A competitive and a blocking format as well as the use of antigen produced from both EHDV-1-and EHDV-2-infected cells were evaluated. The assay was able to detect specific antibody as early as 7 days after infection and could differentiate animals experimentally infected with EHDV from those experimentally infected with BTV. The diagnostic potential of this assay was demonstrated with field-collected serum samples from cattle, deer, and buffalo.


2021 ◽  
Vol 12 ◽  
Author(s):  
Bochao Liu ◽  
Ze Wu ◽  
Chaolan Liang ◽  
Jinhui Lu ◽  
Jinfeng Li ◽  
...  

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.


2003 ◽  
Vol 10 (3) ◽  
pp. 439-442 ◽  
Author(s):  
F. Roodbari ◽  
M. H. Roustai ◽  
A. Mostafaie ◽  
H. Soleimanjdahi ◽  
R. Sarrami Foroshani ◽  
...  

ABSTRACT Measles is a highly contagious respiratory virus infection, with typical clinical symptoms including maculopapular rash, fever, cough, coryza, and conjunctivitis. Despite implementation of widespread vaccination programs throughout the world, the rates of global morbidity and mortality are still considerable. This study was performed to design a reliable indirect enzyme-linked immunosorbent assay (ELISA) to measure measles-specific immunoglobulin M (IgM). First, human IgM was purified, and then an anti-IgM antibody was produced in rabbits and purified in a multistep process. The rabbit IgG against human IgM was conjugated with peroxidase. Measles virus-infected Vero cells produced viral antigen. One hundred serum samples from infants of 9 to 18 months of age, mostly vaccinated, were evaluated for determining the presence of specific IgM antibodies against measles virus. The samples were also evaluated for neutralizing antibodies against measles virus by a microneutralization test (MNT). By comparing the results of the ELISA with those of MNT, it was demonstrated that ELISA had a sensitivity and specificity of 100 and 92%, respectively. On the other hand, when the results obtained by our ELISA system were compared with those of an imported measles virus IgM ELISA kit (EIAgen; Adaltis Italia SPa, Bologna, Italy), a high level of agreement was shown (k = 0.926).


2004 ◽  
Vol 34 (5) ◽  
pp. 1525-1529 ◽  
Author(s):  
Cristiane Divan Baldani ◽  
Rosangela Zacarias Machado ◽  
Paulo de Tarso Landgraf Botteon ◽  
Felipe Santoro Takakura ◽  
Carlos Luiz Massard

A crude antigenic preparation of Babesia equi was used to develop and establish the suitability of an enzyme-linked immunosorbent assay (ELISA) for the detection of parasite carriers. Optimal dilutions of the antigen, using positive and negative reference sera, were determined by checkboard titrations. The specificity and sensitivity of the ELISA were 100 %. A total of 90 serum samples were taken from horses from the Northeast region of São Paulo State and examined for diagnosis of equine B. equi infection by ELISA. Approximately 75% (n=67) of all the horses tested were found serologically positive for B. equi. These results suggest that the ELISA described may prove to be an appropriate serological test for epidemiological studies on B. equi infections in the field and that equine piroplasmosis is a cause for serious concern in the State of São Paulo, Brazil.


2016 ◽  
Vol 54 (6) ◽  
pp. 1557-1565 ◽  
Author(s):  
Martin Heller ◽  
Nimmo Gicheru ◽  
Georgina Tjipura-Zaire ◽  
Cecilia Muriuki ◽  
Mingyan Yu ◽  
...  

Contagious bovine pleuropneumonia (CBPP) is a severe respiratory disease that is widespread in sub-Saharan Africa. It is caused byMycoplasma mycoidessubsp.mycoides, a bacterium belonging to theMycoplasma mycoidescluster. In the absence of an efficient CBPP vaccine, improved and easy-to-use diagnostic assays for recurrent testing combined with isolation and treatment of positive animals represent an option for CBPP control in Africa. Here we describe the comprehensive screening of 17 immunogenicMycoplasma mycoidessubsp.mycoidesproteins using well-characterized bovine sera for the development of a novel cocktail enzyme-linked immunosorbent assay (ELISA) for laboratory use. Two recombinantMycoplasmaimmunogens, MSC_0136 and MSC_0636, were used to set up a standardized cocktail ELISA protocol. According to the results from more than 100 serum samples tested, the sensitivity and specificity of the novel cocktail ELISA were 85.6% and 96.4%, respectively, with an overall diagnostic accuracy comparable to that of the Office International des Epizooties (OIE)-prescribed serological assays. In addition, we provide a proof of principle for a field-applicable, easy-to-use commercially produced prototype lateral-flow test for rapid (<30-min) diagnosis of CBPP.


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