scholarly journals Pathogenesis and Diagnostic Approaches of Avian Infectious Bronchitis

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Faruku Bande ◽  
Siti Suri Arshad ◽  
Abdul Rahman Omar ◽  
Mohd Hair Bejo ◽  
Muhammad Salisu Abubakar ◽  
...  
Keyword(s):  
Broiler Chickens ◽  
Egg Production ◽  
Egg Quality ◽  
Diagnostic Methods ◽  
Stunted Growth ◽  
Infectious Bronchitis ◽  
Highly Sensitive ◽  
Wide Range ◽  
Diagnostic Approaches ◽  
Polymerase Chain

Infectious bronchitis (IB) is one of the major economically important poultry diseases distributed worldwide. It is caused by infectious bronchitis virus (IBV) and affects both galliform and nongalliform birds. Its economic impact includes decreased egg production and poor egg quality in layers, stunted growth, poor carcass weight, and mortality in broiler chickens. Although primarily affecting the respiratory tract, IBV demonstrates a wide range of tissues tropism, including the renal and reproductive systems. Thus, disease outcome may be influenced by the organ or tissue involved as well as pathotypes or strain of the infecting virus. Knowledge on the epidemiology of the prevalent IBV strains in a particular region is therefore important to guide control and preventions. Meanwhile previous diagnostic methods such as serology and virus isolations are less sensitive and time consuming, respectively; current methods, such as reverse transcription polymerase chain reaction (RT-PCR), Restriction Fragment Length Polymorphism (RFLP), and sequencing, offer highly sensitive, rapid, and accurate diagnostic results, thus enabling the genotyping of new viral strains within the shortest possible time. This review discusses aspects on pathogenesis and diagnostic methods for IBV infection.

scholarly journals Comparative Study of Immune-Diagnostic Tools with Polymerase Chain Reaction in Sub-Clinical Leishmaniasis Isolates

2011 ◽  
Vol 12 (1) ◽  
pp. 34-39 ◽  
Author(s):  
Nazar M Abdalla
Keyword(s):  
Polymerase Chain Reaction ◽  
Skin Test ◽  
Diagnostic Methods ◽  
Diagnostic Tools ◽  
Enzyme Linked Immunosorbent Assay ◽  
Clinical Form ◽  
Chain Reaction ◽  
Leishmanin Skin Test ◽  
Wide Range ◽  
Polymerase Chain

Objective: This study aimed to identify cases of leishmaniasis in the Nuba Mountain area, which is situated in a unique geographical site located in the centre of Sudanese leishmania belt. Wide range of investigations are available for detection of leishmania cases, but still the most reliable and easy test used as screening and epidemiological tool in field studies needs to be evaluated. The most commonly used conventional diagnostic methods direct microscopy and culture have some drawbacks in diagnosing subclinical cases of leishmaniasis. Materials and methods: In this study, comparative properties of various immune-diagnostic tools with Polymerase Chain Reaction used in sub-clinical leishmaniasis isolates were explored. The immune-diagnostic tools involved in this study include- Leishmanin Skin Test (LST), Enzyme Linked Immunosorbent Assay (ELISA) and Direct Agglutination Test (DAT). The study was conducted in the Green Valley village (Rashad Province, South Kordofan State) with a population of 332. Most of the villagers presented with sub-clinical form of leishmaniasis with minor symptoms and signs without the features found in clinical form of visceral leishmaniasis such as fever, diarrhoea, epistaxis, enlarged lymph nodes, spleen and liver. In this study we collected demographic, clinical and epidemiological data using special questionnaire. Leishmanin skin test (LST), ELISA, DAT and PCR for parasite DNA detection were used. Result: The final positive cases detected by PCR were 32 out of 332 belong to L. donovani species. The final positive cases detected by LST were 51.2% of the total population under study, while 11 out of the 37 tested samples were positive by ELISA. All of the 332 villagers showed negative readings by DAT with exception of three individuals who were positive with very high titers. Conclusion: DNA etxtraction and amplification with primers can be a good screening tool in subclinical leishmaniasis isolates. Keyword: Sub-clinical; Leishmaniasis; Leishmanin Skin Test; ELISA; DAT; PCR. DOI: 10.3329/jom.v12i1.5422J Medicine 2011; 12 : 34-39

scholarly journals Development and Evaluation of ELISA and qRT-PCR for Identification of Squash vein yellowing virus in Cucurbits

Plant Disease ◽  
2017 ◽  
Vol 101 (1) ◽  
pp. 178-185 ◽  
Author(s):  
Craig G. Webster ◽  
William W. Turechek ◽  
Weimin Li ◽  
Chandrasekar S. Kousik ◽  
Scott Adkins
Keyword(s):  
Latent Class ◽  
Detection Method ◽  
Diagnostic Methods ◽  
Enzyme Linked Immunosorbent Assay ◽  
Qrt Pcr ◽  
Wide Range ◽  
Vine Decline ◽  
Pcr Method ◽  
Polymerase Chain ◽  
Yellowing Virus

Squash vein yellowing virus (SqVYV) causes viral watermelon vine decline. To facilitate detection of SqVYV, enzyme linked-immunosorbent assay (ELISA) and quantitative reverse-transcription polymerase chain reaction (qRT-PCR) diagnostic methods were developed. Both methods were capable of detecting SqVYV in a wide range of cucurbit hosts. ELISA was able to detect virus in infected host tissue diluted to at least 1:2,560, which was sufficient for detection in symptomatic squash and watermelon plants. The qRT-PCR method was capable of reliably detecting as few as 3.4 copies of a cloned fragment of SqVYV genomic RNA with an average cycle threshold (Ct) value of 36.4. The sensitivities and specificities for each detection method were estimated by latent class analysis for a set of inoculated squash and watermelon plants at two sampling scales. The scales were hierarchical, with individual plants representing the upper scale and samples from the plant representing the lower scale. The number of samples per plant varied from 1 to 8, and a plant was diagnosed positive if any of its samples tested positive. For all analyses, a cutoff Ct of 35 was chosen for qRT-PCR, which is approximately 2.5 cycles lower than the lowest Ct value achieved for mock-inoculated plants (presumed to be a false positive). qRT-PCR showed high sensitivities (≥0.99) at both sampling scales for squash and watermelon, whereas the sensitivities for ELISA ranged from 0.58 to 0.76. The specificities for both tests were very similar (≥0.94), with ELISA sometimes outperforming qRT-PCR. These diagnostic methods provide additional tools for the identification of SqVYV and management of SqVYV-induced watermelon vine decline.

scholarly journals Classical and Variant Avian Infectious Bronchitis Virus Strains

EDIS ◽  
1969 ◽  
Vol 2003 (16) ◽  
Author(s):  
Gary D. Butcher ◽  
David P. Shapiro ◽  
Richard D. Miles
Keyword(s):  
Respiratory Distress ◽  
Infectious Bronchitis Virus ◽  
Egg Production ◽  
Egg Quality ◽  
Publication Date ◽  
Nasal Discharge ◽  
Large Animal ◽  
Severe Respiratory Distress ◽  
Shell Quality ◽  
Infectious Bronchitis

Infectious bronchitis (IB) is an acute and highly contagious respiratory disease of chickens. The disease is characterized by respiratory signs including gasping, coughing, sneezing, tracheal râles, and nasal discharge. In young chickens, severe respiratory distress may occur. In layers, respiratory distress, decrease in egg production, and loss of internal egg quality and egg shell quality are reported. Some strains of the virus cause severe kidney damage and may be associated with high mortality. This document is VM127, one of a series of the Veterinary Medicine-Large Animal Clinical Sciences Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date May 1, 2002. VM127/PS039: Infectious Bronchitis Virus: Classical and Variant Strains (ufl.edu)  

Site-specific modification of proteins by ExoT-mediated ADP-ribosylation

TECHNOLOGY ◽  
2015 ◽  
Vol 03 (01) ◽  
pp. 72-78
Author(s):  
Chia-Lun Jack Tsai ◽  
Slim Sassi ◽  
Brian Seed
Keyword(s):  
Chemical Diversity ◽  
Chain Reaction ◽  
Site Specific ◽  
Bar Codes ◽  
C Terminus ◽  
Highly Sensitive ◽  
Wide Range ◽  
Polymerase Chain ◽  
Highly Sensitive Detection ◽  
Adp Ribosyltransferase

Proteins bearing short sequence tags (ExoTags) can be specifically modified in a reaction catalyzed by the ADP-ribosyltransferase of Pseudomonas ExoT. ExoT tolerates a wide range of substituents at the adenosine N6 position, allowing the convenient installation of chemical diversity at the site of the tag. The ExoTag can be placed at either the N - or the C -terminus of the protein of interest or internally. The minimum tag is Arg-Leu-Ser-Arg (RLSR). Tandem copies of the minimal ExoTag enhance the efficiency of modification and allow modification at multiple sites within the tag. ExoT can be used to conjugate NAD-RNA to ExoTag bearing proteins, providing a convenient method for introducing nucleic acid bar codes for highly sensitive detection of proteins by polymerase chain reaction.

scholarly journals Impact of Heat Stress on Poultry Health and Performances, and Potential Mitigation Strategies

Animals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1266 ◽  
Author(s):  
Sanjeev Wasti ◽  
Nirvay Sah ◽  
Birendra Mishra
Keyword(s):  
Heat Stress ◽  
Broiler Chickens ◽  
Egg Production ◽  
Egg Quality ◽  
Scientific Evidence ◽  
Economic Loss ◽  
Mitigation Strategies ◽  
Variable Degree ◽  
Poultry Industry ◽  
Nutritional Strategies

Heat stress is one of the major environmental stressors in the poultry industry resulting in substantial economic loss. Heat stress causes several physiological changes, such as oxidative stress, acid-base imbalance, and suppressed immunocompetence, which leads to increased mortality and reduced feed efficiency, body weight, feed intake, and egg production, and also affects meat and egg quality. Several strategies, with a variable degree of effectiveness, have been implemented to attenuate heat stress in poultry. Nutritional strategies, such as restricting the feed, wet or dual feeding, adding fat in diets, supplementing vitamins, minerals, osmolytes, and phytochemicals, have been widely studied and found to reduce the deleterious effects of heat stress. Furthermore, the use of naked neck (Na) and frizzle (F) genes in certain breed lines have also gained massive attention in recent times. However, only a few of these strategies have been widely used in the poultry industry. Therefore, developing heat-tolerant breed lines along with proper management and nutritional approach needs to be considered for solving this problem. Thus, this review highlights the scientific evidence regarding the effects of heat stress on poultry health and performances, and potential mitigation strategies against heat stress in broiler chickens and laying hens.

scholarly journals Naturally Occurring Egg Drop Syndrome Infection in Turkeys

2007 ◽  
Vol 76 (3) ◽  
pp. 415-421 ◽  
Author(s):  
Z. Biđin ◽  
I. Lojkić ◽  
M. Mikec ◽  
B. Pokrić
Keyword(s):  
Egg Production ◽  
Egg Quality ◽  
Haemagglutination Inhibition ◽  
Clinical Signs ◽  
Virus Genome ◽  
Chain Reaction ◽  
Naturally Occurring ◽  
Polymerase Chain ◽  
Etiological Agents ◽  
Quality Production

A decrease in the egg quality, production, fertility and hatchability without serious clinical signs of illness was recorded in turkey fl ocks in Croatia at the beginning of 2002. It was assumed that the egg drop syndrome virus might be one of the etiological agents responsible for the abnormalities in the egg production. The systematic serological monitoring, using a haemagglutination inhibition test, showed that the antibodies to the egg drop syndrome virus existed in 94.4 and 55.1% of the sera analysed in 2002 and 2003, respectively. The haemagglutination inhibition titres ranged from 16 to 128. The sera samples were randomly collected from 11 - to 46-week-old hens from the affected fl ocks. The serological evidence of the egg drop syndrome virus infection was confirmed by detection of the presence of the virus genome in the turkey sera by the polymerase chain reaction. Vaccination of the 18- and 25-week-old turkey hens against the egg drop syndrome virus started in March 2003. After this period, the presence of antibodies to the egg drop syndrome virus (the haemagglutination inhibition titres between 16 and 256) was found in 96.7% of the analysed sera, while the egg production reached normal or higher values for the Nicholas hybrid line of turkeys.

Genetic changes in layer breeding: Historical trends and future prospects

2000 ◽  
Vol 27 ◽  
pp. 20-28 ◽  
Author(s):  
Rudolf Preisinger ◽  
Dietmar K. Flock
Keyword(s):  
Genetic Variation ◽  
Egg Production ◽  
World Wide ◽  
Egg Quality ◽  
Selection Index ◽  
Pure Line ◽  
Genetic Progress ◽  
Housing Systems ◽  
Wide Range ◽  
Breeding Programmes

SummaryIn commercial egg type chicken breeding three and four way crosses are used to produce commercial layers. The primary breeders are using closed nucleus breeding programmes, with birds kept under maximum biosecurity. All grand parents and parents are produced from a closed nucleus for the world wide demand of commercial layers. The breeding goals have been focused for several decades on increasing number of eggs per hen housed. Additional traits have become more important during the last decade, i.e. feed efficiency, internal and external egg quality and general adaptability. Prior to each selection, weights for individual traits within the selection index are adjusted to meet market demands. Breeding stock and commercial layers have to be bred to perform adequately in a variety of systems ranging from large intensive cage units to free range management under different environmental conditions world-wide.Despite intensive selection for egg production the decrease in genetic variation observed in closed commercial lines is not yet critical. Peak production is approaching the biological limit of one egg a day. During this period genetic and phenotypic variation have been significantly reduced. But for early production (sexual maturity) and late production (persistency) genetic variation is still high. In a mating scheme avoiding full and half sib matings no serious inbreeding depression is observed. To achieve continued future genetic progress, selection pressure will shift to other traits like internal and external egg quality and perhaps behaviour traits which still respond to selection.Primary breeders are responding to this challenge by testing pedigreed cross-line hens in a wide range of environments and housing systems while the pure-line elite stock is kept under conditions of maximum biosecurity. Marker assisted selection is already part of commercial breeding programmes. In the past, blood typing has been used to improve Marek's resistance, whereas today anonymous microsatellites which are linked to traits of economic interest are used for selection. In particular, selection between full sib males can give a major improvement.The whole industry is getting more specialised. While the genetic potential of the birds is improved management and nutrition have also to be adapted to changing demands. The general goal for the future is to breed chickens with the ability to function well within a wider range of production conditions and do not respond to the slightest stress.

scholarly journals Significance of single β-mannanase supplementation on performance and energy utilization in broiler chickens, laying hens, turkeys, sows, and nursery-finish pigs: A meta-analysis and systematic review

2021 ◽  
Author(s):  
Elijah G Kiarie ◽  
Samantha Steelman ◽  
Marco Martinez
Keyword(s):  
Broiler Chickens ◽  
Egg Production ◽  
Laying Hens ◽  
Egg Quality ◽  
Meta Analysis ◽  
Average Daily Gain ◽  
Nutrient Utilization ◽  
Energy Utilization ◽  
Linear Polymers ◽  
The Impact

Abstract This review will give a brief description of β-mannans, abundance in feedstuffs, utility of supplemental feed β-mannanase and subsequent animal responses. Soybean products and co-products of processing palm, coconut and guar seeds are the major sources of β-mannans in poultry and livestock feed. β-mannans are linear polymers of mannose residues linked by β-1,4 glycosidic bonds and their ingestion elicit undesirable and metabolically costly responses. Web of Science was searched to retrieve published studies for meta-analyses of the impact of supplemental β-mannanase on performance and digestibility in pigs and poultry. The mean difference (MD) between ß-mannanase and control on average daily gain (ADG, g/d) was +0.23 (P=0.013; 95% CI 0.05; 0.41), +10.8 g/d (P=0.0005; 95% CI of 6.6; 15.0 g/day) and +20.68 (P<0.000; 95% CI of 17.15; 24.20 g/day) for broiler chickens, nursery pigs and grow-finish pigs, respectively. The MD on β-mannanase improvement on FCR was -0.02 (P<0.0001) with 95% CI (-0.03; -0.02) suggesting a 2-to-3-point FCR improvement in broiler chickens. ß-mannanase improvement on gain to feed (G:F) was +13.8 g/kg (P=0.027; 2.1; 25.4 g/kg) and +8.77 g/kg (6.32; 11.23 g/kg) in nursery and grow-finish pigs, respectively. β-mannanase improved AMEn by 47 kcal/kg (P=0.0004) with 95% CI (28.8; 65.7 kcal/kg) in broiler chickens. The improvement of gross energy digestibility in pigs was 1.08 percentage unit with 95% CI (0.90; 1.26) translating to the release of between 30.6 and 42.8 kcal/kg of digestible energy. Although data was limited, β-mannanase improved egg production but had no impact on egg quality in laying hens. Turkeys may be more adversely affected by ß-mannans because of the high protein/ amino acids requirements necessitating higher dietary inclusion of soybean meal. However, growth performance and feed efficiency responses of turkeys fed diets supplemented with β-mannanase was variable. In summary, ß-mannanase supplementation improved performance linked to energy and nutrient utilization. However, the magnitude of response was variable within and between species indicating further application refinement is warranted to achieve consistent efficacy, including an improved understanding of the functional contribution of β-mannans hydrolysis products.

scholarly journals RT-LAMP CRISPR-Cas12/13-Based SARS-CoV-2 Detection Methods

Diagnostics ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1646
Author(s):  
Kasturi Selvam ◽  
Mohamad Ahmad Najib ◽  
Muhammad Fazli Khalid ◽  
Suharni Mohamad ◽  
Fahreddin Palaz ◽  
...  
Keyword(s):  
Reverse Transcription ◽  
Quantitative Polymerase Chain Reaction ◽  
Diagnostic Techniques ◽  
Diagnostic Methods ◽  
Detection Methods ◽  
Molecular Diagnostic ◽  
Public Attention ◽  
Laboratory Equipment ◽  
Highly Sensitive ◽  
Polymerase Chain

Coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has attracted public attention. The gold standard for diagnosing COVID-19 is reverse transcription–quantitative polymerase chain reaction (RT-qPCR). However, RT-qPCR can only be performed in centralized laboratories due to the requirement for advanced laboratory equipment and qualified workers. In the last decade, clustered regularly interspaced short palindromic repeats (CRISPR) technology has shown considerable promise in the development of rapid, highly sensitive, and specific molecular diagnostic methods that do not require complicated instrumentation. During the current COVID-19 pandemic, there has been growing interest in using CRISPR-based diagnostic techniques to develop rapid and accurate assays for detecting SARS-CoV-2. In this work, we review and summarize reverse-transcription loop-mediated isothermal amplification (RT-LAMP) CRISPR-based diagnostic techniques for detecting SARS-CoV-2.

Sign in / Sign up

Export Citation Format

Share Document