Development and Application of a Multilocus Sequence Typing Scheme for Streptococcus gallolyticus subsp. gallolyticus

Abstract

Streptococcus gallolyticus subsp. gallolyticus (formerly known as S. bovis biotype I) is a commensal of the gastrointestinal tract in animals and in up to 15% of healthy humans. Furthermore, it is a facultative pathogen that can cause infectious endocarditis, mastitis, and septicemia. The number of infections is increasing, but the transmission routes and zoonotic potential remain unknown. To assess the zoonotic potential and characterize the epidemiological structure of S. gallolyticus subsp. gallolyticus, we established a multilocus sequence typing (MLST) scheme. We amplified and sequenced internal fragments of seven housekeeping genes. The resulting sequences were analyzed with BioNumerics software 6.6 by using the unweighted-pair group method using average linkages algorithm. A total of 101 S. gallolyticus subsp. gallolyticus strains isolated from animals, humans, and environmental samples were analyzed and divided into 50 sequence types. Our first results highlight the importance of this MLST scheme for investigating the epidemiology, transmission patterns, and infection chains of S. gallolyticus subsp. gallolyticus.

Genomics, evolution, and molecular epidemiology of the Streptococcus bovis / Streptococcus equinus complex (SBSEC)

“…In contrast, Dumke et al (2014) focused exclusively on Sgg from the Western hemisphere including human Sgg strains (n = 30) from Germany, USA and Belgium. They further included European animal isolates (mainly birds, cows and horses, n = 49), several Sgg strains (n = 18) from unknown sources and an environmental isolate.…”

“…Recently, multi locus sequence type (MLST) assays were developed for species of the SBSEC (Dumke et al, 2014;Shibata et al, 2014;C. Jans unpublished data).…”

“…The MLST schemes by Dumke et al (2014) and Shibata et al (2014) provide a first insight into strain lineages, global epidemiology and associated virulence traits and pathologies of the S. gallolyticus branch. Both MLST schemes share members of the S. gallolyticus branch as targets, but they employ different approaches, strain pools and objectives.…”

“…They further included European animal isolates (mainly birds, cows and horses, n = 49), several Sgg strains (n = 18) from unknown sources and an environmental isolate. Thereby, strains displayed still great variability resulting in 50 STs out of 101 Sgg strains of which 29 STs were divided into 10 CCs and 21 remaining STs were unique (Dumke et al, 2014).…”

Streptococcus gallolyticus subsp. gallolyticus from Human and Animal Origins: Genetic Diversity, Antimicrobial Susceptibility, and Characterization of a Vancomycin-Resistant Calf Isolate Carrying a vanA -Tn 1546 -Like Element

“…gallolyticus isolates from humans and animals have been described previously (8,10), including the existence of particular virulent clones with increased invasion and adherence abilities, which favor bloodstream infections (11)(12)(13). A recent multilocus sequence typing (MLST)-based study demonstrated a lack of specificity for any particular host or geographical location (10).…”