Obstructive pyelonephritis due to New Delhi metallo-β-lactamase-5-producing Escherichia coli in an elderly Japanese who had never traveled abroad

Abstract

The predominant types of carbapenemase (CP) produced by CP-producing Enterobacterales vary by region. Here, we report a case of pyelonephritis caused by Escherichia coli producing New Delhi metallo-β-lactamase-5 (NDM-5) and having a mutation in penicillin-binding protein 3 (PBP3) in an elderly Japanese who had never traveled abroad. An 84-year-old man residing in a nursing home and having left pyeloureteral junction stenosis was hospitalized because of fever and abdominal pain. Physical examination and computed tomography scanning showed findings consistent to left obstructive pyelonephritis. A ureteral stent was placed and administration of ceftriaxone started empirically, which improved the patient’s symptoms on the next day. The administered antibiotic was switched to intravenous fosfomycin on day 4 because CP-producing E. coli was detected in the blood and the urine collected from the patient on admission, which was given until day 18. The isolated strains, whose sequence type was ST410, had the bla_NDM-5 gene located on an IncX3-type plasmid and a mutation of p.P333_Y334insYRIN in PBP3. Because epidemiological data of E. coli ST410 and that with PBP3 mutations have been limited in Japan, further studies are needed to characterize these groups of E. coli in this country.