title: Studies on ampicillin resistance in Achromobacter xylosoxidans. Brief report.
abstract: Population analyses of susceptibility to ampicillin in ampicillin-susceptible and ampicillin-resistant strains of Achromobacter xylosoxidans revealed the existence of ampicillin-resistant subpopulations in ampicillin-susceptible isolates. Bacteria resistant to a concentration four times the one that inhibited the majority population had a frequency of 10(-3) to 10(-4). Strains isolated from aqueous environments are often found susceptible to ampicillin, while sporadic cases of infections with A. xylosoxidans are often caused by ampicillin-resistant strains. We suggest that the isolation from clinical specimens of ampicillin-susceptible strains, therefore, may be an indication of nosocomial infections due to recently contaminated aqueous solutions or medical equipment.
authors.affiliation: Department of Clinical Microbiology, Odense University Hospital, Denmark.
authors.forename: B
authors.initials: B
authors.lastname: Gahrn-Hansen
authors.forename: K
authors.initials: K
authors.lastname: Siboni
mesh_terms: D000421:Alcaligenes / Q000187:drug effects*; D000667:Ampicillin / Q000494:pharmacology*; D000668:Ampicillin Resistance; D001424:Bacterial Infections / Q000382:microbiology; D003428:Cross Infection / Q000382:microbiology; D004866:Equipment Contamination; D006801:Humans; D014876:Water Pollution
chemical_list: D000667:Ampicillin