Project description:A comparative genomic approach was used to identify large sequence polymorphisms among Mycobacterium avium isolates obtained from a variety of host species. DNA microarrays were used as a platform for comparing mycobacteria field isolates with the sequenced bovine isolate Mycobacterium avium subsp. paratuberculosis (Map) K10. ORFs were classified as present or divergent based on the relative fluorescent intensities of the experimental samples compared to Map K10 DNA. Map isolates cultured from cattle, bison, sheep, goat, avian, and human sources were hybridized to the Map microarray. Three large deletions were observed in the genomes of four Map isolates obtained from sheep and four clusters of ORFs homologous to sequences in the Mycobacterium avium subsp. avium (Maa) 104 genome were identified as being present in these isolates. One of these clusters encodes glycopeptidolipid biosynthesis enzymes. One of the Map sheep isolates had a genome profile similar to a group of Mycobacterium avium subsp. silvaticum (Mas) isolates which included four independent laboratory stocks of the organism traditionally identified as Maa strain 18. Genome diversity in Map appears to be mostly restricted to large sequence polymorphisms that are often associated with mobile genetic elements. Keywords: Comparative genomic hybridization
Project description:With the aid of a biochip, carrying representative sequences from approximately 2200 sequences from the genome of isolate 9a5c from X. fastidiosa (Xf), microarray-based comparisons have been performed with 6 different Xf isolates obtained from citrus plants (Table 1). Four of these isolates (56a, 9.12c, 187b, and 36f) were obtained from CVC-affected trees and are representatives of the most prevalent Xf haplotypes found in sweet orange orchards across the state of São Paulo, while isolate CV21 was obtained from a non-symptomatic tree from the same region. Isolate Fb7, on the other hand, was obtained from a sweet orange tree that displayed symptoms of “Pecosita”, a disease similar to CVC that occurs in some citrus-growing regions of Argentina. Keywords: Comparative Genomic Hybridization
Project description:Genomic surveillance of vancomycin-resistant Enterococcus faecium reveals local spread of a linear plasmid conferring a nutrient utilization advantage
