Major Uropathogenic Escherichia coli Strain Isolated in the Northwest of England Identified by Multilocus Sequence Typing

Abstract

A total of 88 uropathogenic Escherichia coli isolates, including 68 isolates from urine and 20 isolates from blood, were characterized by multilocus sequence typing (MLST). MLST has identified an important genetic lineage of E. coli, designated sequence type 131 (ST-131), represented by 52 of these isolates, 51 of which were resistant to extended-spectrum cephalosporins. ST-131 appears to be a drug-resistant uropathogenic strain of E. coli responsible for causing urinary tract infections and bacteremia and is widely disseminated among both community and hospital patients from different geographical areas in the northwest of England. Application of MLST has helped to define the population biology which may underpin the epidemiology of pathogenic E. coli strains. The portability of MLST allows the accurate monitoring of this antibiotic-resistant uropathogenic strain of E. coli and will enhance surveillance for this important group of organisms.Urinary tract infection (UTI) is the most common laboratory-confirmed bacterial infection encountered in medical practice in Europe and North America (9). Escherichia coli is a major cause of UTI, and it accounts for approximately 70 to 95% of community-acquired cases and 50% of all hospitalacquired infections (9). These organisms are responsible for significant social and economic costs for both communities and public health resources. It has been estimated that 150 million cases of UTI occur on a global basis per year and cost about 6 billion dollars for national health resources (6).UTI due to E. coli can progress to bacteremia, which is associated with significant mortality. E. coli is recognized as the one of the two most common causes of bacteremia in England and Wales, and the Health Protection Agency reported 32.5 bacteremia cases per 100,000 subjects in 2005 (7). There is no comprehensive surveillance for community-acquired UTIs in England, and currently, there is only voluntary national surveillance for bacteremia; therefore, it is very difficult to estimate the true incidence of UTI infections and monitor the spread of these organisms (12).In recent years, there has been an increase in the occurrence cephalosporin-resistant strains of E. coli causing UTI and invasive infections (10). These organisms, which are often also resistant to other widely used antibiotics such as fluoroquinolones and trimethoprim, have particular clinical significance due to the limited therapeutic options that are available. Furthermore, the prevention and control of the spread of uropathogenic E. coli infections are hampered by a poor understanding of the population biology of these pathogens. The potential of particular lineages of antibiotic-resistant or uropathogenic E. coli to disseminate and cause disease is unknown. Improved strain characterization and phylogenetic analysis would improve our understanding of the epidemiology of this pathogen and will allow the development of a rapid assay for monitoring of uropathogenic E. coli.Multilocus sequence typing (MLST) is a DNA sequencebas...

Contribution of QnrA, a Plasmid-Mediated Quinolone Resistance Peptide, to Survival of <i>Escherichia coli</i> Exposed to a Lethal Ciprofloxacin Concentration

“…Serotypes O1, O6, O18, and O25 are frequently detected in E. coli isolates obtained from patients with urinary tract infections (14)(15)(16). Strains O74 and O78 were frequent serotypes detected among E. coli isolates obtained from stool specimens of 2,563 healthy adult volunteers of our investigation conducted at a Public Health Center in 2010.…”

Genetic Diversity and Virulence Profiles of Escherichia coli Isolates Causing Spontaneous Bacterial Peritonitis and Bacteremia in Patients with Cirrhosis

“…Together with ST131 and ST69, these STs are frequently associated with urinary tract infections (16,35). ST95 is also found in strains that cause neonatal meningitis, whereas ST73 has recently been identified in adherent-invasive isolates associated with Crohn's disease (4, 23).…”

“…Recent studies have documented the existence of lineages of genetically related E. coli strains, designated clonal groups, which commonly cause urinary tract infections and other extraintestinal infections in various host populations (6,9,12,16,(20)(21)(22)35).…”

Population Analysis and Epidemiological Features of Inhibitor-Resistant-TEM-β-Lactamase-Producing Escherichia coli Isolates from both Community and Hospital Settings in Madrid, Spain

“…ST131-B2 is widely disseminated among both community and hospital patients and also in healthy persons and companion animals (15,18,29). This clone corresponds to a widespread uropathogenic E. coli strain causing urinary tract infections and bacteremia (17,33,34) and represents 3 out of 18 isolates (17%) of our collection. This result denotes that factors other than clonality might have an influence on the low level of representation of IRT producers, including plasmid epidemiology, the emergence of mutations leading to the IRT phenotype, or even the fitness cost associated with these mutations.…”