1. Genetic Diversity of ' Candidatus Liberibacter asiaticus' Revealed by Short Tandem Repeats and Prophage Typing Indicates Population Homogeneity in Brazil.
- Author
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da Silva PA, Fassini CG, Sampaio LS, Dequigiovanni G, Zucchi MI, and Wulff NA
- Subjects
- Asia, Brazil, China, Florida, Genetic Variation, Japan, Microsatellite Repeats, North America, Prophages, Sequence Analysis, DNA, Citrus, Plant Diseases microbiology, Polymerase Chain Reaction methods, Rhizobiaceae pathogenicity
- Abstract
' Candidatus Liberibacter asiaticus' is the most common huanglongbing-associated bacteria, being present in Asia, South, Central, and North America. Genomic approaches enabled sequencing of ' Ca . L. asiaticus' genomes, allowing for a broader assessment of its genetic variability with the application of polymerase chain reaction (PCR)-based tools such as microsatellite or short tandem repeat (STR) analysis. Although these tools contributed to a detailed analysis of strains from Japan, China, and the United States, Brazilian strains were analyzed in either too few samples with several STRs or in several strains with only a single microsatellite and a single PCR marker. We used 573 ' Ca . L. asiaticus' strains, mainly collected from São Paulo State (SPS), in our genetic analyses, employing three STRs and several prophage PCR markers. STR revealed a homogeneous population regardless of sampling year or geographic regions of SPS. Thirty-eight haplotypes were recognized with a predominance of VNTR_005 higher than 10 repeats, with VNTR_002 and VNTR_077 containing 11 and 8 repeats, respectively. This haplotype is indicated as class HE, which comprised 80.28% of strains. Classes HA and HB, predominant in Florida, were not found. A new genomic organization in the junction of prophages SC2 and SC1 is prevalent in Brazilian strains, indicating gene rearrangement and a widespread occurrence of a type 1 prophage as well as the presence of a type 2-like prophage. Our results indicate that ' Ca. L. asiaticus' populations are homogeneous and harbor a new genomic organization in prophages type 1 and 2.
- Published
- 2019
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