title: Analysis of the mechanisms of resistance to several antimicrobial agents in Shigella spp. causing travellers' diarrhoea.
abstract: Eighty isolates of Shigella spp. (37 Shigella flexneri and 43 Shigella sonnei) from patients with travellers' diarrhoea were studied. Susceptibility tests revealed high levels of resistance, especially to ampicillin (65%), tetracycline (78%) and trimethoprim (75%), and particularly among the S. flexneri isolates. Dihydrofolate reductase 1 genes (dfrA1) were prevalent among the trimethoprim-resistant isolates, while oxa genes predominated among the ampicillin-resistant isolates. Chloramphenicol resistance was associated with production of chloramphenicol acetyltransferase, while nalidixic acid-resistant isolates had a single mutation in the gyrA gene. The results indicate a continuing need for resistance surveillance and rational use of antimicrobial agents.
authors.affiliation: Centre de Salut Internacional, Universitat de Barcelona, Barcelona, Spain.
authors.forename: M M
authors.initials: MM
authors.lastname: Navia
authors.forename: J
authors.initials: J
authors.lastname: Gascón
authors.forename: J
authors.initials: J
authors.lastname: Vila
mesh_terms: D000667:Ampicillin / Q000494:pharmacology; D000890:Anti-Infective Agents / Q000494:pharmacology*; D002701:Chloramphenicol / Q000494:pharmacology; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D004405:Dysentery, Bacillary / Q000209:etiology / Q000382:microbiology*; D008826:Microbial Sensitivity Tests; D012760:Shigella / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D013752:Tetracycline / Q000494:pharmacology; D014195:Travel
chemical_list: D000890:Anti-Infective Agents; D002701:Chloramphenicol; D000667:Ampicillin; D013752:Tetracycline