Escherichia coli ST131-O25b:H4 (E. coli ST131) (E. coli ST131)

Escherichia coli ST131-O25b:H4 is a globally disseminated, multidrug-resistant (MDR) clone of extraintestinal pathogenic E. coli (ExPEC) that is a leading cause of urinary tract infections and bloodstream infections (Mathers et al., 2015). It is characterized by its frequent association with the CTX-M-15 extended-spectrum beta-lactamase (ESBL), which confers resistance to most beta-lactam antibiotics, including third-generation cephalosporins (Nicolas-Chanoine et al., 2014). This strain is particularly concerning due to its combination of high virulence factors and extensive antibiotic resistance, often leaving carbapenems as the last line of defense (Pitout & DeVinney, 2017). The ST131 lineage is further subdivided, with the H30-Rx subclone being the most prevalent and resistant worldwide (Johnson et al., 2013). Understanding its genomic structure and resistance mechanisms is critical for developing new therapeutic strategies and diagnostic tools to combat its spread (Price et al., 2013).

Other names

ST131O25b:H4Extraintestinal pathogenic Escherichia coli ST131ExPEC ST131E. coli sequence type 131

Antibiotics targeting this pathogen act through various mechanisms: carbapenems (e.g., meropenem) inhibit cell wall synthesis by binding to penicillin-binding proteins; aminoglycosides (e.g., amikacin) inhibit protein synthesis by binding to the 30S ribosomal subunit; and polymyxins (e.g., colistin) disrupt the outer cell membrane (Pitout & DeVinney, 2017).