Occurrence of risk factors and antimicrobial resistance due to genes encoding extended–spectrum β-lactamase (ESBL) – and/or AmpC β-lactamase–producing Escherichia coli isolated from the hospitalised patients

This survey was focused to gain insight into the emergence of antimicrobial resistance mechanisms within overall of 913 Escherichia coli isolates and risk factors for cohort of 77 randomly selected patients. Host–related risk factors mostly involved lower urinary tract disease 50 (64.9%) times, renal insufficiency in 28 (36.4%) subjects, introduced urinary catheter in 43 (55.8%) as well as previous antibiotic therapy within 66 (85.7%) patients. Out of all investigated E. coli, 726 (79.5%) were determined as ESBL producers, 43 (4.7%) ESBL and AmpC producers, 46 (5.1%) AmpC positive and 87 (9.5%) were multidrug–resistant. Most of the times were revealed the following genes: blaCTX–M 767 (84.0%, p < 0.001), blaTEM 682 (74.7%, p < 0.001), blaSHV 89 (9.7%, p = 0.001). Less frequently accounted for resistance determinants as follows genes: blaCIT 38 (4.2%), blaDHA 32 (3.5%, p = 0.001), blaEBC 17 (1.9%, p < 0.001) and blaFOX 21 (2.3%, p < 0.05). Concerning 32 (3.5%) E. coli isolates from bloodstream infections, 26 (81.2%) posed CTX–M-15 producers and 2 (6.2%) isolates were CTX–M-3 originators. Within presumed E. coli pathogens, RFLP assessment exhibited in 2 patterns extended–spectrum character of mutations on blaTEM genes encoding positions considering amino acid sites 104, 238 and 240. Regarding antimicrobial resistance, the lowest rate was ascertained toward meropenem (0.4%), ertapenem (3.8%), tigecycline (1.4%) and amikacin (6.3%).