Open AccessMolecular Characterization and Prophage DNA Contents of Streptococcus agalactiae Strains Isolated from Adult Skin and Osteoarticular Infections
Author(s) -
Mazen Salloum,
Nathalie van der Mee-Marquet,
Anne-Sophie Domelier,
Laurence Arnault,
Roland Quentin
Publication year - 2010
Publication title -
journal of clinical microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.349
H-Index - 255
eISSN - 1070-633X
pISSN - 0095-1137
DOI - 10.1128/jcm.01820-09
Subject(s) - prophage , multilocus sequence typing , streptococcus agalactiae , biology , serotype , microbiology and biotechnology , dna , lysogenic cycle , strain (injury) , typing , streptococcus , genetics , genotype , gene , bacteria , escherichia coli , bacteriophage , anatomy
Skin and osteoarticular infections (SKI and OAI, respectively) account for almost one-third ofStreptococcus agalactiae infections in nonpregnant adults. We evaluated the genetic diversity and phylogeny of 58S. agalactiae strains responsible for adult SKI or OAI and of 61S. agalactiae strains from cases of adult human colonization (HCol) by serotyping and multilocus sequence typing (MLST). We also assessed the prophage DNA content of the genomes of these strains by a PCR-based method. We found that 63% of SKI and 56% of OAI occurred in people aged 55 years and over. Overall, 71% of SKI strains were of serotype Ia or V, and 91% of OAI strains were of serotype Ia, III, or V. Strains of clonal complexes 1 and 23 (CC1 and CC23) were associated with 79% of SKI cases and 62% of OAI cases. Seven groups of strains, groups A, B, C, D, E, F, and G, were obtained by performing a hierarchical analysis on the basis of prophage DNA-PCR data. We found that 85% of CC1 strains clustered in DNA prophage group D, the group with the highest prophage DNA content (average, 4.4; average of absolute deviations [AVEDEV], 0.9). The CC23 strains displayed the greatest diversity in prophage DNA fragment content, but 47% of CC23 strains clustered in group B, which also had a high average prophage DNA content per strain (average, 2.3; AVEDEV, 0.6). Many (65%) of the OAI strains were in prophage DNA group D, whereas 83% of the SKI strains were in prophage DNA groups B and D. These data suggest thatS. agalactiae strains from CC1 and CC23 may be subject to particular transduction mechanisms in gene recombination, rendering them particularly capable of invading the skin, bone, or joints in adults.