Fosfomycin Resistance in Escherichia coli, Pennsylvania, USA.

Hind Alrowais,Yohei Doi,Sangeeta Sastry,Caressa N Spychala,Adeel A Butt,Qinglan Guo,Christi L Mcelheny

doi:10.3201/eid2111.150750

Abstract

Fosfomycin resistance in Escherichia coli is rare in the United States. An extended-spectrum β-lactamase–producing E. coli clinical strain identified in Pennsylvania, USA, showed high-level fosfomycin resistance caused by the fosA3 gene. The IncFII plasmid carrying this gene had a structure similar to those found in China, where fosfomycin resistance is commonly described.

Highlights

Fosfomycin resistance in Escherichia coli is rare in the United States
We report a case of persistent colonization with a fosA3-carrying E. coli strain in a patient in Pennsylvania, USA
E. coli YD472 was highly resistant to fosfomycin (MIC >1,024 μg/mL by Etest), which was confirmed by using the agar dilution method with Mueller-Hinton agar and glucose-6-phosphate (25 μg/mL) as an additive, as endorsed by the Clinical and Laboratory Standards Institute [5]. Given this high-level resistance, PCR was conducted on YD472 to identify fosA3 and fosC2, which have been reported as acquired fosfomycin resistance genes among recent E. coli strains in Japan, China, and South Korea [3,6,7]

Summary

Introduction

Fosfomycin resistance in Escherichia coli is rare in the United States. An extended-spectrum β-lactamase–producing E. coli clinical strain identified in Pennsylvania, USA, showed high-level fosfomycin resistance caused by the fosA3 gene. A recent study of E. coli strains collected at veterans’ hospitals in the United States included ciprofloxacin-resistant and extended-spectrum β-lactamase–producing strains. In E. coli, the plasmid-mediated fosfomycin resistance gene fosA3, which encodes a glutathione Stransferase, was first identified in a fosfomycin-resistant E. coli strain in Japan [3].

Results

Conclusion