Sorbitol-fermenting enterohemorrhagic Escherichia coli O157:H- isolates from Czech patients with novel plasmid composition not previously seen in German isolates

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F75010330%3A_____%2F17%3A00011867" target="_blank" >RIV/75010330:_____/17:00011867 - isvavai.cz</a>

Výsledek na webu

<a href="http://aem.asm.org/content/83/23/e01454-17" target="_blank" >http://aem.asm.org/content/83/23/e01454-17</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1128/AEM.01454-17" target="_blank" >10.1128/AEM.01454-17</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Sorbitol-fermenting enterohemorrhagic Escherichia coli O157:H- isolates from Czech patients with novel plasmid composition not previously seen in German isolates

Popis výsledku v původním jazyce

Sorbitol-fermenting (SF) enterohemorrhagic Escherichia coli (EHEC) O157: H- strains, first identified in Germany, have emerged as important pathogens throughout Europe. Besides chromosomally encoded Shiga toxin 2a (the major virulence factor), several putative virulence loci, including the hly, etp, and sfp operons, encoding EHEC hemolysin, type II secretion system proteins, and Sfp fimbriae, respectively, are located on the 121-kb plasmid pSFO157 in German strains. Here we report novel SF EHEC O157: H- strains isolated from patients in the Czech Republic. These strains share the core genomes and chromosomal virulence loci encoding toxins (stx(2a) and the cdtV-ABC operon) and adhesins (eae-gamma, efa1, lpfA(O157OI-141), and lpfA(O157OI-154)) with German strains but differ essentially in their plasmids. In contrast to all previously detected SF EHEC O157: H- strains, the Czech strains carry two plasmids, of 79 kb and 86 kb. The 79-kb plasmid harbors the sfp operon, but neither of the plasmids contains the hly and etp operons. Sequence analyses demonstrated that the 79-kb plasmid (pSFO157 258/98-1) evolved from pSFO157 of German strains by deletion of a 41,534-bp region via homologous recombination, resulting in loss of the hly and etp operons. The 86-kb plasmid (pSFO157 258/98-2) displays 98% sequence similarity to a 92.7-kb plasmid of an extraintestinal pathogenic E. coli bloodstream isolate. Our finding of this novel plasmid composition in SF EHEC O157: H- strains extends the evolutionary history of EHEC O157 plasmids. Moreover, the unique molecular plasmid characteristics permit the identification of such strains, thereby facilitating further investigations of their geographic distribution, clinical significance, and epidemiology. MPORTANCE Since their first identification in Germany in 1989, sorbitol-fermenting enterohemorrhagic Escherichia coli O157: H- (nonmotile) strains have emerged as important causes of the life-threatening disease hemolytic-uremic syndrome in Europe. They account for 10 to 20% of sporadic cases of this disease and have caused several large outbreaks. The strains isolated throughout Europe share conserved chromosomal and plasmid characteristics. Here we identified novel sorbitol-fermenting enterohemorrhagic E. coli O157: H- patient isolates in the Czech Republic which differ from all such strains reported previously by their unique plasmid characteristics, including plasmid number, composition of plasmid-carried virulence genes, and plasmid origins. Our findings contribute substantially to understanding the evolution of E. coli O157 strains and their plasmids. In practical terms, they enable the identification of strains with these novel plasmid characteristics in patient stool samples and thus the investigation of their roles as human pathogens in other geographic areas.

Název v anglickém jazyce

Sorbitol-fermenting enterohemorrhagic Escherichia coli O157:H- isolates from Czech patients with novel plasmid composition not previously seen in German isolates

Popis výsledku anglicky

Sorbitol-fermenting (SF) enterohemorrhagic Escherichia coli (EHEC) O157: H- strains, first identified in Germany, have emerged as important pathogens throughout Europe. Besides chromosomally encoded Shiga toxin 2a (the major virulence factor), several putative virulence loci, including the hly, etp, and sfp operons, encoding EHEC hemolysin, type II secretion system proteins, and Sfp fimbriae, respectively, are located on the 121-kb plasmid pSFO157 in German strains. Here we report novel SF EHEC O157: H- strains isolated from patients in the Czech Republic. These strains share the core genomes and chromosomal virulence loci encoding toxins (stx(2a) and the cdtV-ABC operon) and adhesins (eae-gamma, efa1, lpfA(O157OI-141), and lpfA(O157OI-154)) with German strains but differ essentially in their plasmids. In contrast to all previously detected SF EHEC O157: H- strains, the Czech strains carry two plasmids, of 79 kb and 86 kb. The 79-kb plasmid harbors the sfp operon, but neither of the plasmids contains the hly and etp operons. Sequence analyses demonstrated that the 79-kb plasmid (pSFO157 258/98-1) evolved from pSFO157 of German strains by deletion of a 41,534-bp region via homologous recombination, resulting in loss of the hly and etp operons. The 86-kb plasmid (pSFO157 258/98-2) displays 98% sequence similarity to a 92.7-kb plasmid of an extraintestinal pathogenic E. coli bloodstream isolate. Our finding of this novel plasmid composition in SF EHEC O157: H- strains extends the evolutionary history of EHEC O157 plasmids. Moreover, the unique molecular plasmid characteristics permit the identification of such strains, thereby facilitating further investigations of their geographic distribution, clinical significance, and epidemiology. MPORTANCE Since their first identification in Germany in 1989, sorbitol-fermenting enterohemorrhagic Escherichia coli O157: H- (nonmotile) strains have emerged as important causes of the life-threatening disease hemolytic-uremic syndrome in Europe. They account for 10 to 20% of sporadic cases of this disease and have caused several large outbreaks. The strains isolated throughout Europe share conserved chromosomal and plasmid characteristics. Here we identified novel sorbitol-fermenting enterohemorrhagic E. coli O157: H- patient isolates in the Czech Republic which differ from all such strains reported previously by their unique plasmid characteristics, including plasmid number, composition of plasmid-carried virulence genes, and plasmid origins. Our findings contribute substantially to understanding the evolution of E. coli O157 strains and their plasmids. In practical terms, they enable the identification of strains with these novel plasmid characteristics in patient stool samples and thus the investigation of their roles as human pathogens in other geographic areas.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

30303 - Infectious Diseases

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Applied and Environmental Microbiology

ISSN

0099-2240

e-ISSN

1098-5336

Svazek periodika

83

Číslo periodika v rámci svazku

23

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

14

Strana od-do

nestrankovano

Kód UT WoS článku

000415617800004

EID výsledku v databázi Scopus

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