title: Typhoid fever due to a Salmonella typhi strain of reduced susceptibility to fluoroquinolones.
abstract: OBJECTIVE: To report a case of typhoid fever contracted in Portugal in 1994 due to a Salmonella typhi isolate which had reduced susceptibility to fluoroquinolone (MIC 1 mg/L of ciprofloxacin) and high level resistance to nalidixic acid (MIC greater-than-or-equal 56 mg/L). METHODS: Molecular studies of reduced susceptibility to fluoroquinolones comprised complementation tests with a wild-type allele and sequencing directly from PCR products of the gyrA gene. RESULTS: Complementation tests and DNA sequencing showed that a mutation occurred in the gyrA gene of this clinical isolate, resulting in a substitution of phenylalanine for serine at position 83 of GyrA. CONCLUSIONS: Because quinolones may be regarded as a treatment of choice in typhoid fever, it seems important now to recommend cautious use of these drugs as first-line therapy and possibly use of nalidixic acid resistance as a marker for detection of 'first-step' resistance to fluoroquinolones in S. typhi.
authors.affiliation: Laboratoire de Microbiologie Médicale, Hôpital Broussais, Paris, France.
authors.forename: Odile
authors.initials: O
authors.lastname: Launay
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Nguyen Van
authors.forename: Annie
authors.initials: A
authors.lastname: Buu-Hoï
authors.forename: J. F.
authors.initials: JF
authors.lastname: Acar