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Mayaro virus (MAYV), which causes mayaro fever, is endemic to limited regions of South America that may expand due to the possible involvement of Aedes spp. mosquitoes in its transmission. Its effective control will require the accurate identification of infected individuals, which has been restricted to nucleic acid-based tests due to similarities with other emerging members of the Alphavirus genus of the Togaviridae family; both in structure and clinical symptoms. Serological tests have a more significant potential to expand testing at a reasonable cost, and their performance primarily reflects that of the antigen utilized to capture pathogen-specific antibodies. Here, we describe the assembly of a synthetic gene encoding multiple copies of antigenic determinants mapped from the nsP1, nsP2, E1, and E2 proteins of MAYV that readily expressed as a stable chimeric protein in bacteria. Its serological performance as the target in ELISAs revealed a high accuracy for detecting anti-MAYV IgM antibodies. No cross-reactivity was observed with serum from seropositive individuals for dengue, chikungunya, yellow fever, Zika, and other infectious diseases as well as healthy individuals. Our data suggest that this bioengineered antigen could be used to develop high-performance serological tests for MAYV infections., (© 2021. The Author(s).)

We describe a method for retrieving sequences with one or two point mutations of a given target sequence, which are present in a DNA population at a frequency of 1 in 466 x 10(3) and 1 in 28 x 10(3) molecules, respectively. By stringent hybridization to a stable, chemically immobilized probe, a large excess of unrelated fragments is removed, and the bound sequences are dissociated and amplified. By repeating the hybridization-amplification cycles twice, we achieved an estimated enrichment of 404,000-fold and 1612-fold, respectively, which was confirmed by cloning the resultant products and sequencing 35 clones. This procedure can be applied to retrieve mutated sequences that exist at an extremely low frequency in a DNA population.

A novel synthetic 323-bp gene with the open reading frame of a multiple-epitope polypeptide has been assembled and cloned. The gene is engineered by contiguous alignment of selected epitopes and functional domains of the hepatitis B virus envelope proteins separated by pairs of glycine residues. High-level bacterial production of this 100-amino acid (approx. 10 kDa) protein has been achieved and the gene product is stable. ELISA and Western blot experiments using epitope-specific antisera confirm that the corresponding epitopes are present in the engineered protein.