First Detection of Isolate Co-Harboring Fosfomycin Resistance Gene and ctx-m Among Gram Negative Urine Isolates in a Turkish Hospital.

The most common gram-negative pathogens in urinary tract infections are and . Therapy that is often empirical relies on local antibiotic resistance data, hence monitorization of antimicrobial resistance periodically in each hospital is a requirement. In this study, antibiotic susceptibility profiles of consecutive urinary isolates ( [ = 235] and [ = 56]) of adult patients collected between February 2018 and February 2019 from inpatients in Hacettepe University Hospital were assessed. Isolates resistant to fosfomycin (minimum inhibitory concentration >32 mg/L) were further investigated for the presence of , , and Fosfomycin susceptibility was determined by agar dilution method. Broth microdilution method was performed for amikacin, gentamicin, ceftazidime, ceftriaxone, meropenem, ciprofloxacin, tigecycline, trimethoprim/sulfamethoxazole (TMP/SMX), colistin, and piperacillin/tazobactam (PIP/TAZ). PCR method was employed to investigate , , , and . Existence of gene was confirmed by sequencing. Resistance rates to amikacin, gentamicin, ceftazidime, ceftriaxone, meropenem, ciprofloxacin, tigecycline, TMP/SMX, colistin, and PIP/TAZ were 2.7%, 18.5%, 25.4%, 33.0%, 3.4%, 45.4%, 2.4%, 43.6%, 6.2%, and 23.7%, respectively. Sixteen isolates (5.5%) were resistant to fosfomycin. Resistance was most frequently observed in ( = 9). gene was detected in one fosfomycin-resistant isolate. This isolate also carried and genes could not be detected in any of the isolates. In this study, we report for the first time the existence of in Turkey and its association with the gene. As a result of increasing bla producing isolates globally, increase in fosfomycin resistance may be expected in near future.