title: In vivo acquisition of ceftriaxone resistance in Salmonella enterica serotype anatum.
abstract: The emergence of resistance to antimicrobial agents within the salmonellas is a worldwide and severe problem. A case of treatment failure due to the emergence of resistance to ceftriaxone in Salmonella enterica serotype Anatum was studied. S. enterica serotype Anatum and Escherichia coli, both of which are susceptible to ceftriaxone, were initially isolated from a diabetic patient hospitalized for the treatment of wound and urinary tract infections. Resistant S. enterica serotype Anatum and E. coli strains were isolated concomitantly 2 weeks after the initiation of ceftriaxone therapy. The patient eventually died of a sepsis caused by the ceftriaxone-resistant salmonella. PCR, nucleotide sequence analysis, and DNA-DNA hybridization identified a bla(CTX-M-3) gene located on a 95.1-kb plasmid from the ceftriaxone-resistant isolates of S. enterica serotype Anatum and E. coli. The plasmid was proved to be conjugative. Molecular fingerprinting showed that the susceptible and resistant strains were genetically indistinguishable. The emergence of resistance to ceftriaxone in S. enterica serotype Anatum was due to the in vivo acquisition of a plasmid containing the bla(CTX-M-3) gene and was the cause for treatment failure in this patient.
authors.affiliation: Department of Clinical Pathology, Chang Gung Memorial Hospital, Taoyuan, Taiwan.
authors.forename: Lin-Hui
authors.initials: LH
authors.lastname: Su
authors.forename: Cheng-Hsun
authors.initials: CH
authors.lastname: Chiu
authors.forename: Chishih
authors.initials: C
authors.lastname: Chu
authors.forename: Mei-Hui
authors.initials: MH
authors.lastname: Wang
authors.forename: Ju-Hsin
authors.initials: JH
authors.lastname: Chia
authors.forename: Tsu-Lan
authors.initials: TL
authors.lastname: Wu
mesh_terms: D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use*; D002443:Ceftriaxone / Q000494:pharmacology / Q000627:therapeutic use*; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D017809:Fatal Outcome; D005260:Female; D005838:Genotype; D006801:Humans; D006824:Hybridization, Genetic; D010957:Plasmids / Q000235:genetics; D019779:Salmonella enterica / Q000145:classification* / Q000187:drug effects / Q000302:isolation & purification; D018805:Sepsis / Q000188:drug therapy* / Q000382:microbiology; D012703:Serotyping; D014552:Urinary Tract Infections / Q000188:drug therapy* / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents; D002443:Ceftriaxone