Molecular characterization of invasive and non-invasive Streptococcus pyogenes isolates from Romania

Abstract

In 2002, the Romanian National Reference Laboratory was invited to join the Strep-EURO project to study invasive Streptococcus pyogenes infections. During 2003 and, a total of 33 isolates recovered from invasive disease were received from eight Romanian counties. For comparison, 102 isolates from non-invasive disease, as well as a collection of 12 old invasive strains (isolated between 1967 and 1980) were included. All isolates were characterized by several methods: T and emm typing, presence of the fibronectin-binding protein F1 gene (prtF1), serum opacity factor (sof), and superantigen (SAg) genes (speA, speB, speC, speF, speG, speH, ssa and smeZ). The recent invasive isolates exhibited 19 emm-types, of which emm1, emm81, emm76, emm49 and emm78 covered 57 % of the strains. Furthermore, multilocus sequence typing analysis revealed nine new sequence types, corresponding to emm types 1, 12, 49, 81, 92, 100, 106 and 119. The non-invasive isolates comprised 24 different emm types with a predominance of emm1 and 12; the old invasive strains were of eight emm types, of which four were unique for this group. All isolates harboured speB and speF; smeZ was detected in all invasive strains, except for the emm49 and emm81 isolates. The majority of isolates from carriers, and patients with pharyngitis were prtF1 positive, most of these (14 strains) being emm12. High tetracycline resistance rates were noted among both invasive and control isolates (54 % and 35 %, respectively), whereas macrolide resistance rates were low (3 % and 5 %, respectively). Active and continuing surveillance is required to provide an accurate assessment of the disease burden and to provide epidemiological data on the character of isolates in Romania. INTRODUCTIONGroup A streptococci (GAS, Streptococcus pyogenes) is one of the major human pathogens (Carapetis et al., 2005), giving rise to various suppurative complications of infection, e.g. acute throat and skin infections, as well as severe systemic disease such as cellulitis, puerperal sepsis, pneumonia, septicaemia, necrotizing fasciitis (NF) and streptococcal toxic shock syndrome (STSS) (Cunningham, 2000). In addition, GAS infections can give rise to nonsuppurative sequelae, such as acute rheumatic fever and acute glomerulonephritis (Cunningham, 2000).The heterogeneity exhibited by the N terminus of the Mprotein, the major GAS virulence factor (Bisno et al., 2003), is used in the M-serotyping technique (Lancefield, 1962). The emm gene (encoding the M-protein) is successfully targeted in sequence typing (Johnson et al., 2006). Another GAS surface protein, T-protein, was used as a basis for a crude, but widely used subdivision of strains (Moody et al., 1965). The variable presence of an apoproteinase serum opacity factor (SOF) enabled separation of Abbreviations: CSF, cerebrospinal fluid; GAS, group A streptoccocci; iGAS, invasive group A streptococci; MLST, multilocus sequence typing; NF, necrotizing fasciitis; PFGE, pulsed-field gel electrophoresis; RFLP, restriction fragment length polymorphis...

emm 81, The Predominant Group a Streptococcus from North India in Year 2003 in Context to Adhesion, Invasion and Antimicrobial Susceptibility Pattern

“…In the year 2003, the study conducted at our laboratory showed predominance of emm 81 type in North Indian community, which has also been reported from other countries [8,16,18,19,20]. Report of association of emm 81 with invasive disease in Sweden and Romania [17,20] prompted us to look for a virulent potential of the circulating predominant emm 81 isolates from our community.…”

“…Report of association of emm 81 with invasive disease in Sweden and Romania [17,20] prompted us to look for a virulent potential of the circulating predominant emm 81 isolates from our community. We focused on adherence and invasion potential of these isolates towards host cell, the process resulting in infection or disease outcome.…”

“…FBP genes, the major contributors of adherence/invasion were screened in isolated emm 81 strains, which showed these strains to possess nine known FBP's to a variable extent, indicating their highly heterogeneous nature. The study conducted by Luca-Harari et al [20] explored the presence of only one FBP gene i.e. prtF1 gene in its isolated emm 81 strains and found all the isolates to possess the same.…”

Epidemiological and molecular characteristics of clinical isolates of Streptococcus pyogenes collected between 2005 and 2008 from Chinese children

“…The genotype emm1.0 and emm12.0 strains were prevalent in invasive and noninvasive diseases (Luca-Harari et al, 2008b). Genetic mutation was the major culprit for the outbreak of S. pyogenes infection.…”

Molecular characterization and evaluation of the emerging antibiotic-resistant Streptococcus pyogenes from eastern India

“…HaeIII vir typing patterns of Australian GAS isolates produced 4 to 8 fragments ranging from 200 bp to 4 kb, where 1.4 kb, 500 bp, and 275 bp were found common in the isolates tested [9]. vir typing patterns of Romania yielded 2 to 8 fragments ranging from 100 bp to 4.2 kb with a common fragment at 1.2 kb [42]. Reports from north India showed 4 to 6 fragments varying from 300 bp to 5 kb where 300 bp, 550 bp and 1.2 kb were common for the majority of isolates [15].…”