The past 2 decades have brought worrying increases in severe Streptococcus pyogenes diseases globally. To investigate and compare the epidemiological patterns of these diseases within Europe, data were collected through a European Union FP-5-funded program (Strep-EURO). Prospective population-based surveillance of severe S. pyogenes infection diagnosed during 2003 and 2004 was undertaken in 11 countries across Europe (Cyprus, the Czech Republic, Denmark, Finland, France, Germany, Greece, Italy, Romania, Sweden, and the United Kingdom) using a standardized case definition. A total of 5,522 cases were identified across the 11 countries during this period. Rates of reported infection varied, reaching 3/100,000 population in the northern European countries. Seasonal patterns of infection showed remarkable congruence between countries. The risk of infection was highest among the elderly, and rates were higher in males than in females in most countries. Skin lesions/wounds were the most common predisposing factor, reported in 25% of cases; 21% had no predisposing factors reported. Skin and soft tissue were the most common foci of infection, with 32% of patients having cellulitis and 8% necrotizing fasciitis. The overall 7-day case fatality rate was 19%; it was 44% among patients who developed streptococcal toxic shock syndrome. The findings from Strep-EURO confirm a high incidence of severe S. pyogenes disease in Europe. Furthermore, these results have identified targets for public health intervention, as well as raising awareness of severe S. pyogenes disease across Europe.
Streptococcus pyogenes (group A streptococcus [GAS]), a major human pathogen (9), has been studied for decades and may give rise to common throat and skin infections as well as to invasive diseases, such as arthritis, septicemia, cellulitis, puerperal fever, necrotizing fasciitis (NF), and streptococcal toxic shock syndrome (STSS) (14). Since the mid-1980s there have been increasing numbers of reports describing severe manifestations of GAS infections; however, the factors underlying the worldwide resurgence of this pathogen remain unknown (20).The M protein, which is encoded by the emm gene, is an important virulence factor and is also an epidemiological marker that is used throughout the world to characterize GAS isolates (5,(21)(22)(23). The type specificity of the M protein, of which more than 100 different types are known, is largely determined by the epitope located in 40 to 50 amino acid residues at the amino terminus (4,16,27). These regions of M proteins have been shown to evoke antibodies that have strong bactericidal activity and that are not likely cross-reactive with
A collection of Enterococcus faecalis strains from clinical isolates, healthy individuals and the environment was screened for the presence of virulence factor genes, such as those for collagenbinding protein (ace), endocarditis antigen (efaA), haemolysin activator (cylA), gelatinase (gelE), aggregation substances (asa1 and asa373), a surface protein (esp) and two novel putative surface antigens (EF0591 and EF3314). Apart from some genes that were present in all strains (ace, efaA and EF3314), the gelE gene was the most common factor, although its presence did not correlate with its expression. The genes that encode Esp and CylA were never detected in endocarditis isolates, whereas an association was noted between the esp gene and isolates from urinary tract infection (UTI) and bacteraemia. An aggregation substance gene was always present in commensal strains. As for gelatinase, the presence of the cylA and asa genes did not correlate completely with their phenotypic expression. Generally, isolates from endocarditis, biliary stents and the environment were equipped with fewer virulence factors than isolates from other sources. UTI strains possessed the highest number of factors.
Group B streptococci (GBS) comprising three different sets of isolates (31 invasive, 36 noninvasive, and 24 colonizing isolates) were collected in Italy during the years 2002 to 2005. Clonal groups were established by pulsed-field gel electrophoresis (PFGE), and selected isolates were studied by multilocus sequence typing (MLST). GBS isolates were also characterized by classical and molecular techniques for serotyping and protein gene and antibiotic resistance profiling. Some serotypes were significantly associated with a particular isolate population: serotype Ia more frequently corresponded to invasive strains than other strains, serotype V was more frequently encountered among noninvasive strains, and nontypeable strains were more common among isolates from carriers. Four major clonal groups accounted for 52.7% of all isolates: PFGE type 1/clonal complex 1 (CC1) comprised mainly serotype V isolates carrying the alp3 gene, PFGE type 2/CC23 encompassed serotype Ia isolates with the alp1 or alpha gene, PFGE type 3/CC17 comprised serotype III isolates carrying the rib gene, and PFGE type 4/CC19 consisted mainly of serotype II isolates possessing the rib gene. The same serotypes were shared by isolates of different clonal groups, and conversely, isolates belonging to the same clonal groups were found to be of different serotypes, presumably due to capsular switching by the horizontal transfer of capsular genes. Erythromycin resistance (prevalence, 16.5%; 15 resistant isolates of 91) was restricted to strains isolated from patients with noninvasive infections and carriers, while tetracycline resistance was evenly distributed (prevalence, 68.1%; 62 resistant isolates of 91). Most erythromycin-resistant GBS strains were of serotype V, were erm(B) positive, and belonged to the PFGE type 1/CC1 group, suggesting that macrolide resistance may have arisen both by clonal dissemination and by the horizontal transfer of resistance genes.Streptococcus agalactiae (group B streptococcus [GBS]) is one of the leading causes of neonatal sepsis and meningitis (2,20,32). The colonization of the female genital tract with GBS is significantly associated with infections in neonates, and it should be carefully monitored. Moreover, GBS has also been recently recognized as an important pathogen in immunocompromised patients (12, 14, 37). The first-line agent against GBS infection is penicillin, and penicillin resistance among GBS strains has not been reported so far (5). However, for patients allergic to penicillin, macrolides (e.g., erythromycin) and lincosamides (e.g., clindamycin) are the alternative choices for the treatment of GBS infections. In the United States, the frequencies of resistance to erythromycin and clindamycin among GBS isolates have been reported to be approximately 37 and 17%, respectively (16).Two main mechanisms of erythromycin resistance in GBS isolates have been described previously (17,25). One mechanism is macrolide-specific efflux encoded by the mef(A)/mef(E) gene ( Capsular serotyping is the classic method fo...
We recently described the presence of 3 pilus variants in the human pathogen group B streptococcus (GBS; also known as Streptococcus agalactiae), each encoded by a distinct pathogenicity island, as well as the ability of pilus components to elicit protection in mice against homologous challenge. To determine whether a vaccine containing a combination of proteins from the 3 pilus types could provide broad protection, we analyzed pili distribution and conservation in 289 clinical isolates. We found that pilus sequences in each island are conserved, all strains carried at least 1 of the 3 islands, and a combination of the 3 pilus components conferred protection against all tested GBS challenge strains. These data are the first to indicate that a vaccine exclusively constituted by pilus components can be effective in preventing infections caused by GBS, and they pave the way for the use of a similar approach against other pathogenic streptococci.
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