Recent Advancements in the Diagnosis and Management of Livestock and Poultry Diseases
- P.Sridevi, J.Violet Beaulah, KS. Subhadra Ravali, Geetha Ramesh, S. Usha Kumary
Department of Veterinary Anatomy, Madras Veterinary College, Chennai – 600 007.
Introduction
As the human population expands, so does the demand for animal origin food milk, meat, eggs for fulfilment of protein deficit in developing countries. This surge necessitates intensified livestock production to meet the growing needs of a rapidly growing populace. However, this intensified production can inadvertently create conducive environments for the proliferation and transmission of diseases among animals. High-density livestock farming, often practiced to meet the escalating demand, can lead to overcrowding, stress, and compromised immune systems in animals, creating favourable conditions for the emergence and spread of diseases. Moreover, the globalized nature of agriculture means that diseases can rapidly cross borders through trade and travel, posing significant challenges in disease control and management. An array of classical and conventional techniques has been developed and used for the laboratory diagnosis of infectious agents or pathogens. Maintenance of good health status of animals by effective control and treatment of diseases lies in the access to various standard diagnostic tests which are rapid, reliable, precise and highly sensitive and therefore helps in confirming early detection of causative agent. The conventional diagnostic methods are serological, cell culture and electron microscopy-based methods, which are either time-consuming or labour-intensive. Latest advances in the molecular biology and biotechnology have opened new avenues in disease diagnosis and therapeutics.
At the World Organization for Animal Health (OIE) Collaborating Centre for the Biotechnology-Based Diagnosis of Infectious Diseases in Veterinary Medicine, at the National Veterinary Institute (SVA) and the Swedish University of Agricultural Sciences (SLU) in Uppsala, Sweden. Ten infectious tads, listed as notify able to the OIE—FMD, swine vesicular disease (SVD), vesicular stomatitis (VS), CSF, ASF, bluetongue (BT), African horse sickness (AHS), Newcastle disease (ND), highly pathogenic avian influenza (HPAI) and swine influenza (SI)—were the subjects of this international research project of the EU.
The new diagnostic assays were developed to improve the current detection of the targeted pathogens
Serological methods
- Counter-immunoelectrophoresis, immunofluorescence in cell culture, ELISA, radio immunoassay, immune adherence haemagglutination assay, reverse passive hemagglutination assay, latex agglutination (LA), chemiluminescent immunoassay, and immunochromatography test.
- ELISA have always been the field applicable diagnostic methods in the detection of various farm animal diseases caused by FMDV, Clostridium perfringens, M. Bovis, and Escherichia coli. Dot-ELISA has been employed in diagnosing various important poultry diseases. Sandwich ELISA and competitive ELISA are used frequently in the commercial diagnostic kits for animal diseases worldwide.
- ICT assays mostly utilized mammalian igg in commercial diagnostic kits, however, avian igy antibodies, with added advantages over the mammalian igg, have been employed for the detection of norovirus, rotavirus, and astrovirus in the fecal samples with good sensitivity and specificity ranging between 90% and 95%
Nucleic Acid Amplification methods
- PCR has been used in veterinary diagnostics for specific genomic detection, e.g.infectious bovine rhinotracheitis virus, foot-and-mouth disease virus, bovine viral diarrhoea virus, buffalopox virus, ephemeral fever virus and the detection of avian influenza and Newcastle disease poultry pathogens in recent outbreaks in the USA has been made with PCR.
- The RT-PCR has played a vital role in diseases diagnosis especially RNA viral infections, for example, influenza viruses, rotavirus, bluetongue virus, foot-and-mouth disease virus, etc
- Nested PCR (npcr) has been used in canine corona virus, West Nile virus and of Babesia bovis and Babesia bigemina
- LATE-PCR is highly appropriate for high-throughput field applications, e.g. Clinical analysis, biodefense, forensics and DNA sequencing
- Real-time RT-PCR is the most sensitive, informative technique yielding rapid results, with the only drawback of high cost of start-up and of reagents. It has been employed for detection of bluetongue virus, foot-and-mouth disease virus and bovine piroplasmid
- PCR and real-time PCR methods are regularly used in the detection of Campylobacter, Shigella, bovine respiratory syncytial virus, Eimeria, Salmonella species
- A multiplex PCR assay to detect H5N1 and other human respiratory pathogens and mastitis in animals has been developed
- Colony PCR This PCR is specifically to screen the bacterial colonies. Fung’s double-tube method for rapid detection and confirmation of Clostridium perfringens
- Taqman real-time RT-PCR assay has been developed for rapid detection and quantification of Japanese encephalitis virus in swine blood and mosquito vectors
- TAS used for direct detection of RNA-containing viruses, e.g. Hepatitis C virus, this technique can be used for detection of low amount of certain bacterial and fungal pathogens
- LAMP can be used as a simple test in the field or at the point of disease outbreak. LAMP-based commercial detection kits for bacterial and viral pathogens are available. LAMP has also been developed for foot and-mouth disease virus, bluetongue virus, peste des petits, brucellosis, bovine popular stomatitis, sheep pox, and goat pox
- A multiplex real-time nucleic acid sequence-based amplification (qnasba) system for the simultaneous detection of rotavirus
Hybridization-based methods
- The most common and widely used hybridization-based method is in situ hybridization, which could utilize fluorescent (FISH) or chromogenic (CISH) molecules.
- The CISH-based assays for the rapid characterization of microorganisms, such as Mycobacterium species
- Taqman-based probes
- Molecular beacons
- FRET-based probes
- PNA probes are now increasingly available to detect target DNA. Fluorescent PNA probes, followed by signal amplification were used to differentiate between pathogenic and non-pathogenic M. Tuberculosis.
Peptide nucleic acid and aptamers
Polymerase spiral reaction (PSR) -has been developed for detection of
- Brucella spp.
- Bovine herpesvirus-1
- Canine parvovirus 2
Aptamers
- A rapid label-free visual PNA-based assay for detection and pathotyping of Newcastle disease virus has also been reported
- PNA-based beacons have also been used in HIV
- DNA aptamers in particular have many advantages over antibodies.
- As biocomponents in biosensors (aptasensors),
- Potential diagnostic assays, especially in the detection of toxins such as brevetoxin-2, potent marine neurotoxins, marine biotoxinpalytoxin, β-bungarotoxin (β-butx), and a neurotoxin from the venom of Bungarus multicinctus
- The serological detection of Mycobacterium bovis, Cryptosporidium parvum and prion disease
- RNA aptamers can be used in different fields of science, diagnostic, prognostic and therapeutic
Next-generation sequencing
NGS technologies have revolutionized genomics and pathogen detection. They enable the simultaneous sequencing of thousands to millions of DNA fragments. NGS can be used to identify pathogens, their genetic variations, and understand the genetic factors that influence susceptibility to diseases.
- Avian influenza virus, classical swine fever virus and Bluetongue viruses
- Nanopore sequencing has proved a revolutionary diagnostic tool in detecting the Ebola virus, influenza viruses and porcine viral enteric disease
CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) technology can be used for highly specific and rapid pathogen detection. CRISPR-based diagnostic tests can quickly identify the presence of a pathogen’s DNA or RNA in animal samples, allowing for early disease detection
DNA microarrays are used to detect multiple pathogens simultaneously in a single sample. They are particularly useful for surveillance and early detection of diseases in both farm and pet animals
Biosensors
The development of biosensors that can detect specific biomarkers associated with diseases in animals. These sensors can be incorporated into wearable devices for continuous monitoring of animal health
- Serological diagnosis of the BHV-1
- Nanowire-based immunosensor for bovine viral diarrhea virus (BVDV)
- Luminescence resonance energy transfer based biosensors for the ultrasensitive detection of the H7 strain, quartz crystal microbalance (QCM)_based
- Immunosensors to detect H5N1
- Spectro optical microchip sensors for foot-and-mouth disease virus (FMDV)
- Specific biochemical recognition helped in the identification of E. Coli in cattle
- In C. Perfringens detection,
- Epsilon-toxin-specific monoclonal antibody was immobilized onto single-walled carbon nanotubes and adjusted to detect relevant concentrations of toxin in nanomolar and were comparable to ELISA-based results.
- Many other methods like mass spectrometry, microarrays, and MALDI-TOF are also under employment for the detection of many farm animals-associated pathogens, like Francisella tularensis, Staphylococcus aureus, Enterococcus faecalis, E. Coli
PNA Clamping:
- Pnas can be used for genotyping and identification of genetic markers associated with desirable traits in livestock.
- By designing specific PNA probes, researchers can selectively amplify and detect particular DNA sequences, aiding in breeding programs and genetic selection
Single nucleotide polymorphisms (snps) are genetic variations that can be associated with disease susceptibility and other traits in livestock. Microarrays can be used to detect and genotype snps in the DNA of animals, which is valuable for breeding programs and disease association studies
Serogenomics: This emerging field combines serology and genomics to provide a more comprehensive understanding of the immune response to viral infections. It can help identify correlates of protection and improve vaccine development
Metagenomics: Metagenomic sequencing can identify the presence of a wide range of viruses in a sample without prior knowledge of the virus. It is valuable for surveillance of viruses
Conclusion
Advances in biotechnology have led to the development of novel diagnostic techniques that enable quick and accurate identification of a wide range of diseases in livestock animals and birds. Remarkable financial losses, a fragile food supply chain, and infectious diseases insufficient access to food and the high upkeep costs associated with the agriculture sectors poultry and farm animals. Furthermore, these conditions have a significant both endemic and occasional zoonoses carry a danger of human transmission. both traditional and Conventional diagnostic techniques require a lot of work, take a long time, are less sensitive and challenging to satisfy the novel pathogen diagnostics’ requirements. The Short-term advances will support sensitive, precise pathogen diagnostics as well as targeted discoveries. A range of new diagnostic assays were developed to improve the current detection of the targeted viruses, such as novel real-time PCR assays, isothermal amplification methods, probes and novel ELISA systems. Innovations will always be bringing the new applications in the diagnostics for the improved versions of techniques.
Recent Advancements in Diagnosis and Management of Livestock and Poultry Diseases
