Fosfomycin Susceptibility of ESBL Positive and Negative Escherichia coli and Klebsiella spp. Resistant to at Least One Carbapenem

Extended spectrum beta-lactamase (ESBL) production and increased carbapenem resistance in Enterobacterales members have increased the interest in fosfomycin, an ancient antibiotic. In the study, susceptibility of fosfomycin was investigated in ESBL positive and ESBL negative Escherichia coli and Klebsiella spp. strains resistant to at least one carbapenem (ertapenem, imipenem, meropenem). Carbapenem resistant E.coli and Klebsiella spp. isolated from various clinics and intensive care units, and outpatients during a one year period (January-December 2017) were included the study. Ot the 64 E.coli isolates, fosfomycin susceptibility of ESBL-negative strains (41/43 95.3 %) were higher than ESBL positives (17/21, 80.9 %). However, there was no statistically significant correlation between the presence of ESBL and the sensitivity of fosfomycin (p>0.05). In Klebsiella spp., fosfomycin susceptibility in ESBL negative isolates was 42/53 (79.2 %) with 16/29 (55.1 %) in ESBL positives. The relationship between ESBL and fosfomycin resistance in Klebsiella spp. was statistically significant (p0.05). Fosfomycin can be used in resistant bacterial infections other than urinary tract with its high sensitivity in carbapenem-resistant E.coli and Klebsiella strains.

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