Fluoroquinolone-resistant Salmonella Paratyphi A

摘要

To the Editor: Fluoroquinoloneshave been the drug of choice for treat-ing typhoid and paratyphoid feversince the beginning of the 1990s.Multidrug-resistant strains began toprevail in disease-endemic areas, andformer first-line antimicrobial drugs,such as chloramphenicol, were some-times ineffective (1). In recent years,however, strains with decreased sus-ceptibility to quinolones haveemerged, and clinical treatment fail-ure is a serious concern (2–5).An 87-year-old woman wasreferred from a local clinic toYokohama Municipal Citizen'sHospital in July 2002 becauseSalmonella enterica serovar ParatyphiA was detected in her urine. She hadno subjective symptoms such as painon urination or urinary urgency, andher temperature was normal. She hadnever had paratyphoid fever, and shehad not traveled abroad. No other per-son in the community had paraty-phoid. Before being admitted to thehospital, she had experienced frequentepisodes of urinary tract infection andhad been empirically treated eachtime with oral antimicrobial drugs,including ciprofloxacin. She had beengiven a dose of 600 mg/day for 7days, 25 times in the last 4 years.The patient did not display anyabnormal findings on physical exami-nation. S. Paratyphi A was not detect-ed in the urine but was confirmed inthe stool; therefore, the previousreport of bacteriuria could have beendue to contamination of a urine sam-ple with feces. An ultrasound showeda polyp and multiple stones in hergallbladder. A carrier state was sus-pected. Bile was obtained by duode-nal aspiration and was positive for S.Paratyphi A. The patient was consid-ered to be an asymptomatic cholecys-tic carrier of S. Paratyphi A