Development of haemagglutination assay for titration of porcine circovirus type 2

Porcine circovirus type 2 (PCV2) was one of the most economically important viral pathogens in all the swine-producing countries and often resulted in tremendous economic losses for the swine industry. As PCV2 could not cause cytopathogenic effects while propagated in infected cells, many complicated experiments should be performed to titrate its virus titer. In this study we developed a simple and effective hemagglutination assay for titration of virus titer of PCV2. To develop the hemagglutination assay, a recombinant bispecific nanobody (BsNb) against PCV2 and chicken red blood cells (cRBCs) was constructed based on two nanobodies (NbPCV11 and NbRBC48) which were selected from the non-immunized nanobody library, respectively. The hemagglutination assay was used to titrate the virus titer of PCV2 propagated in cell culture by simple naked-eye observation within 30 min, with the detection limit of 10^4.09 tissue culture infective dose 50 (TCID₅₀)/mL, excellent specificity and reproducibility. Therefore, the hemagglutination assay had potential to be a rapid, reliable, cost-effective, user-friendly qualitative and semi-quantitative tool for titration of virus titer of PCV2 during the vaccine manufacturing process.

Meta-analysis of prevalence of bovine herpes virus 1 in cattle in Mainland China

Bovine herpesvirus 1 (BHV-1), an important pathogen of cattle, can cause severe clinical syndromes including respiratory disease, genital disease, and late-term abortions, as well as neurological and systemic disease in cattle. For assessing the prevalence of BHV-1 infection in mainland China, a systematic review and meta-analysis was conducted. In this systematic review and meta-analysis, we searched English and Chinese literature databases for published paper regarding the prevalence of BHV-1 in cattle in China from inception to May 20, 2018. Search strings included if they reported the cattle samples of more than 30 cattle and provided information that allowed us to establish the prevalence of BHV-1. Moreover, we excluded repeated studies, reviews, other hosts studies, as well as studies with inconsistent data, incomplete information or only provided prevalence data, and out of mainland China data. We extracted how many cattle have BHV-1 infection from the obtained studies, moreover, and calculated pooled prevalence of BHV-1 infection in cattle. The data of 41 articles (including data on 43,441 cattle) are compliant with the standards. The pooled prevalence of BHV-1 in cattle in China was 40%, the pooled prevalence of BHV-1 in cattle from Northeast China (24%) was significant lower than those from other regions. In addition, the prevalence of BHV-1 was associated with publication time of paper, detection methods, age of cattle, and clinical symptoms (pneumonia, abortion etc.).Our findings suggest that BHV-1 is common in cattle in mainland China. It is necessary to monitor the prevalence of BHV-1 in cattle and the powerful and effective regulatory measures should be taken out to prevent the spread of BHV-1.

Rapid Waterborne Pathogen Detection with Mobile Electronics

Pathogen detection in water samples, without complex and time consuming procedures such as fluorescent-labeling or culture-based incubation, is essential to public safety. We propose an immunoagglutination-based protocol together with the microfluidic device to quantify pathogen levels directly from water samples. Utilizing ubiquitous complementary metal–oxide–semiconductor (CMOS) imagers from mobile electronics, a low-cost and one-step reaction detection protocol is developed to enable field detection for waterborne pathogens. 10 mL of pathogen-containing water samples was processed using the developed protocol including filtration enrichment, immune-reaction detection and imaging processing. The limit of detection of 10 E. coli O157:H7 cells/10 mL has been demonstrated within 10 min of turnaround time. The protocol can readily be integrated into a mobile electronics such as smartphones for rapid and reproducible field detection of waterborne pathogens.

Enfermedad neurológica bovina con diagnóstico no conclusivo en la región norte de Colombia. Análisis histológico e inmunohistoquímico

<p>La enfermedad neurológica bovina genera altas pérdidas económicas en las ganaderías y algunos de sus agentes etiológicos son zoonóticos, hechos que hacen prioritario su estudio. El objetivo del trabajo fue identificar antígenos del virus de la rabia y del herpes virus bovino-5 (BoHV-5) en muestras de encéfalos de bovinos archivados como casos de enfermedad neurológica con diagnóstico no conclusivo. Se seleccionaron 10 muestras del laboratorio del Instituto Colombiano Agropecuario -ICA- de Montería. Los tejidos fueron analizados mediante histopatología e inmunohistoquímica; para esta última técnica fueron utilizados tres anticuerpos: dos contra antígenos del virus de la rabia a una dilución de 1:200 y uno contra BoHV-5 a una dilución de 1:100. Histológicamente en nueve casos se observaron lesiones que variaron de tipo y severidad; la identificación de antígenos del virus de la rabia se demostró en 20% (2/10) de los casos y en ningún caso se demostró la presencia BoHV-5. Se discute sobre los resultados histopatológicos e inmunohistoquímicos y se concluye la importancia de asociar los hallazgos de las dos técnicas para establecer la etiología de la enfermedad neurológica, especialmente en casos con diagnóstico inconcluso.</p>