Prevalence and Characteristics of the Epidemic Multiresistant Escherichia coli ST131 Clonal Group among Extended-Spectrum Beta-Lactamase-Producing E. coli Isolates in Copenhagen, Denmark

Abstract

We report the characteristics of 115 extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli clinical isolates, from 115 unique Danish patients, over a 1-year study interval (1 October 2008 to 30 September 2009). Forty-four (38%) of the ESBL isolates represented sequence type 131 (ST13)1, from phylogenetic group B2. The remaining 71 isolates were from phylogenetic groups D (27%), A (22%), B1 (10%), and B2 (3%). Serogroup O25 ST131 isolates (n ‫؍‬ 42; 95% of ST131) comprised 7 different K antigens, whereas two ST131 isolates were O16:K100:H5. Compared to non-ST131 isolates, ST131 isolates were associated positively with CTX-M-15 and negatively with CTX-M-1 and CTX-M-14. They also were associated positively with 11 virulence genes, including afa and dra (Dr family adhesins), the F10 papA allele (P fimbria variant), fimH (type 1 fimbriae), fyuA (yersiniabactin receptor), iha (adhesin siderophore), iutA (aerobactin receptor), kpsM II (group 2 capsules), malX (pathogenicity island marker), ompT (outer membrane protease), sat (secreted autotransporter toxin), and usp (uropathogenicity-specific protein) and negatively with hra (heat-resistant agglutinin) and iroN (salmochelin receptor). The consensus virulence gene profile (>90% prevalence) of the ST131 isolates included fimH, fyuA, malX, and usp (100% each), ompT and the F10 papA allele (95% each), and kpsM II and iutA (93% each). ST131 isolates were also positively associated with community acquisition, extraintestinal pathogenic E. coli (ExPEC) status, and the O25, K100, and H4 antigens. Thus, among ESBL E. coli isolates in Copenhagen, ST131 was the most prevalent clonal group, was community associated, and exhibited distinctive and comparatively extensive virulence profiles, plus a greater variety of capsular antigens than reported previously. E scherichia coli is the most common agent of urinary tract infection (UTI) and Gram-negative bacteremia. E. coli sequence type 131 (ST131) is a recently emerged worldwide pandemic clonal group, causing widespread antimicrobial-resistant infections (1). Although many studies have examined various aspects of E. coli ST131 in diverse locales and clinical contexts (1, 2), little is known about ST131's O:K:H serotypes, especially in relation to community versus health care site of acquisition, coresistance phenotypes, extended-spectrum beta-lactamase (ESBL) variants, and pulse-field gel electrophoresis (PFGE) types. Such data are needed to more fully understand the epidemiology of ST131 and to help guide diagnostic and preventive efforts.CTX-M-type beta-lactamases have become the dominant ESBLs worldwide during the past decade (3). The responsible bla CTX-M genes are known to be associated with conjugative plasmids and certain successful bacterial clones, notably ST131 (4).Here we assessed the prevalence of E. coli ST131 among 115 consecutive ESBL-producing E. coli isolates from 115 patients (2008)(2009) from 3 hospitals and 100 general practitioners' offices in Copenhagen, Denmark. Subsequently, we compared ST131 and ...

Diagnostic Potential of Monoclonal Antibodies Specific to the Unique O-Antigen of Multidrug-Resistant Epidemic Escherichia coli Clone ST131-O25b:H4

“…This might be explained by the lower number of average virulence factors expressed in ST131 isolates than in non-MDR strains (11). However, compared with other lineages of ESBL-producing E. coli isolates, ST131 strains were shown to carry a significantly higher number of virulence genes (9,13,14). The high metabolic potential of this lineage was recently suggested to contribute to its overall success (10,15).…”

Genetic and phenotypic characterisation of Escherichia coli producing cefotaximase-type extended-spectrum β-lactamases: first evidence of the ST131 clone in cats with urinary infections in Italy

“…Only one strain (cat 6) contained the CTX-M-15 gene, and this strain belonged to ST131, presenting the typical characteristics of this sequence type, such as the presence of fyuA, iutA, kpsMII and malX, and allocation to the B2 phylogroup. 29 Over the last decade, the ST131 virulent pandemic clone has emerged in hospitals and in the community worldwide, causing outbreaks of MDR infections across the globe. 30 It has been frequently described as a urinary pathogen in humans, 31 and a fatal case of urosepsis associated with a multi-resistant strain of E. coli ST131 was reported recently 30 Although rarely isolated from companion animals, a recent report found E. coli ST131 to distribute among human and animal household members in Australia, suggesting serious clinical and public health implications.…”

Escherichia coli ST131, an Intriguing Clonal Group

“…Considering all sample types, the prevalence of E. coli ST131 among ESBL-producing E. coli isolates ranged from 22% (Spain) to 66% (United Kingdom) in Europe (mean value, 39% for five European countries) between 2006 and 2011 (20,72,75,96,139). The two studies conducted in Spain, 2 years apart at two hospitals in Galicia and Catalonia, indicated a marked increase in prevalence over this period: 22% in 2006 and 32% in 2008.…”

“…E. coli ST131 strains are mostly of serotype O25:H4, with a specific O25 type, O25b. However, ST131 E. coli isolates of serotype O16:H5 have recently been identified in Japan, Denmark, Australia, Spain, Pakistan, and France (18)(19)(20)(21)(22)(23)(24). Moreover, some E. coli ST131 isolates have been shown to be nontypeable for O or H antigens (18,25).…”