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Specific properties of two enteric adenovirus 41 clones mapped within early region 1A
Insights
Researchers developed DNA hybridization tools for detecting enteric adenoviruses like Ad40 and Ad41, which cause infant diarrhea. These tools enable specific identification of these difficult-to-culture viruses, aiding in diagnosis and research.
Area of Science:
- Molecular Virology
- Medical Microbiology
- Recombinant DNA Technology
Background:
- Enteric adenoviruses, specifically types 40 (Ad40) and 41 (Ad41), are significant causes of infantile diarrhea.
- These viruses belong to the sixth subgenus of human adenoviruses and are challenging to isolate using standard cell culture methods.
- The fastidious nature of enteric adenoviruses necessitates the development of alternative diagnostic and detection strategies.
Purpose of the Study:
- To construct a restriction fragment library of the enteric adenovirus Ad41 genome for developing hybridization-based detection methods.
- To identify specific DNA sequences within Ad41 that can be used for the direct detection of adenoviruses.
- To create tools for differentiating enteric adenoviruses from other human adenovirus serotypes.
Main Methods:
- Cloning of the enteric adenovirus Ad41 genome.
- Mapping of restriction endonuclease cleavage sites (BamHI, EcoRI, HpaI, NruI, PvuI, SalI) on the Ad41 genome.
- Construction of a restriction fragment library using plasmid pBR322 as a vector.
- Isolation and characterization of Ad41 DNA fragments inserted into the vector.
- Hybridization assays using cloned DNA fragments against various adenovirus serotypes.
Main Results:
- A library containing 8 of 10 BamHI fragments of Ad41 DNA was successfully constructed.
- Two key clones were identified: one broadly detects all human adenovirus subgenera, and another specifically detects enteric adenoviruses, particularly Ad41.
- A distinct region (1.5 to 3.3 map units) in the Ad41 genome, corresponding to the 5' portion of early region Ia, showed no detectable homology with other adenovirus serotypes, including Ad40.
Conclusions:
- The developed DNA clones provide valuable tools for the direct detection and differentiation of adenoviruses, especially enteric types.
- The identified unique sequence in Ad41 offers a target for highly specific diagnostic probes.
- These findings advance the capability for rapid and accurate identification of enteric adenoviruses, crucial for managing infantile diarrhea.
Abstract:
Enteric adenovirus type 40 (Ad40) and Ad41 form the sixth subgenus of human adenoviruses. They are associated with infantile diarrhea but cannot be isolated in conventional cell cultures. The genome of the fastidious enteric Ad41 has been cloned, and the cleavage sites of the genome produced by restriction endonucleases BamHI, EcoRI, HpaI, NruI, PvuI, and SalI have been mapped. To develop useful hybridization methods for direct detection of adenoviruses, a restriction fragment library containing Ad41 DNA, with plasmid pBR322 as vector, has been constructed. Clones have been isolated which contain 8 of 10 possible BamHI fragments of Ad41, inserted into the BamHI cleavage site of the vector. Two of these clones are particularly useful for the detection of adenoviruses. One clone detects members of all human adenovirus subgenera, and the second clone is specific for enteric adenoviruses, in particular Ad41. A conspicuous absence of detectable homology was noted at 1.5 to 3.3 map units of the Ad41 genome in hybridizations against other serotypes of adenoviruses, including the closely related enteric Ad40. This sequence corresponds to the 5' portion of early region Ia.