Emergence and spread of three clonally related virulent isolates of CTX-M-15-producing Escherichia coli with variable resistance to aminoglycosides and tetracycline in a French geriatric hospital.

Three types of multidrug-resistant Escherichia coli isolates, called GEN S, GEN R, and AMG S, according to their three different aminoglycoside resistance patterns, were responsible for urinary tract colonization or infection in 87, 12, and 13 new patients, respectively, in a French 650-bed geriatric hospital over a 13-month period. The three E. coli types belonged to the same clone and phylogenetic group (group B2) and had identical transferable plasmid contents (a 120-kb plasmid), beta-lactam and fluoroquinolone resistance genotypes (bla(TEM-1B), bla(CTX-M-15), and double mutations in both the gyrA and the parC genes), and virulence factor genotypes (aer, fyuA, and irp2).

Clinical significance of tolerant strains of streptococci in adults with infective endocarditis.

Objectives: To compare the characteristics of patients with endocarditis due to tolerant and non-tolerant Streptococcus strains.

Patients And Methods: A retrospective nine-year study was conducted in a single tertiary-care hospital. The study included 24 cases of streptococcal endocarditis with known beta-lactam minimal inhibitory and bactericidal concentrations.