Influenza virus and DNA technologies

Influenza viruses belong to the family Orthomyxoviridae that consists of helical, single-stranded RNA. This family also represents a type of enveloped viruses. The virus of four types: A, B, C, and D. The type A and B influenza viruses are mainly disease-causing and clinically relevant for humans. Nowadays various methods or technologies are used to sequence, manipulate the genome of the Influenza virus.

CDC:
CDC (Centres for Disease Control and Prevention) uses the genetic characterization of the flu or influenza virus for the following reasons:

For the determination of the genetic relatedness or resemblances of the same viruses present in each individual.

To observe the evolutionary process of the Influenza virus.

Identification of genetic changes or mutations that might modify the functional properties of the virus. Consider identification of several specified changes associated with the rapid and easy spreading of the influenza viruses causing severe illness, or drug-resistant to the viral drugs.

Production of influenza flu vaccine that is specific to the virus that depends on hereditary information similar between the viruses.

Genetic changes in the virus observed in an animal population can also cause disease in humans.

Influenza viruses are constantly changing, so that memory cells cannot be developed against this infection, in fact over time, all influenza viruses generally undergo genetic changes. So, to know the nature of the genome and its constantly changing properties, the CDC has sequenced the Influenza virus genome by the implementation of some accurate and sensitive sequencing techniques along with a data analysis pipeline.

Scientists are discovering various technologies to identify the influenza virus that majorly affects humans. It is an epidemic disease that affects the respiratory system and also causes variation in genes.

Earlier, scientists have used the “Sanger Dideoxy sequencing method” to monitor the evolution of the influenza virus. The sequencing method helps in identifying the sequence of the virus from the clinical isolates. Often sanger is considered to be a gold standard method that is performed to sequence the partial genome of the virus. However various advanced technology is available in sequencing the entire genome of the virus.

In recent years, advanced technology which is the “Next Generation Sequencing (NGS)” has been performed by the CDC which gives detailed information about the virus. NGS is an advanced technology for detecting the sequence of the virus from individual clinical samples. Thus, Next Generation Sequencing help in identifying the variation in the genomes of the viral particles from every specimen. This sequencing method also gives us information on the coding region of the genome. The information through this advanced technology can be very useful and beneficial for the public health sector in several important ways. The result should be analyzed in detail and carefully by a professionally trained technician in a detailed manner in the context of other available information.

PCR-based diagnostics methods are also used for the comparative analysis of genetic material of several influenza viruses in a sample. Reverse transcriptase PCR or RT-PCR was considered to be the most specific methods for the detection of the Influenza virus and was used for the formation of cDNAs encoding approximately 500-bp gene fragments of influenza virus, which were then undergone the process of cloning, sequencing, reamplification, and spotting to form a glass-bound microarray.

The “microarray technology” is considered to create a revolutionary impression or effect in the study of expression patterns of genes in diverse groups of organisms. Multiplex nano-microarray analysis can be carried out for the identification of viruses. Arrays are usually composed of robotically spotted DNAs or oligonucleotides for analyzing the differential expression of genes and are found to be more recently useful for various applications such as drug discovery, detection of mutation, evolutionary studies, and mapping of the genome.