Antibiotic resistance and adherence properties of Hafnia alvei clinical isolates: a 19-month study in the hospital of Orléans, France.

We studied the epidemiology of antibiotic resistance and adherence properties among all Hafnia alvei clinical isolates collected from August 2003 to February 2005 from patients hospitalized in the hospital of Orléans, France. The isolates were typed by random amplified polymorphic DNA (RAPD), screened for antibiotic resistance and bacterial adherence to A549 respiratory and T24 bladder cells. Six intestinal, 3 respiratory, and 8 isolates from different body sites were collected. A total of 12 RAPD profiles were found, demonstrating a high genetic diversity. All the isolates were resistant to amoxicillin + clavulanate and cephalothin and sensitive to aminoglycosides, fluoroquinolones, cefepime and imipenem. Six isolates had a high-level and constitutive cephalosporinase production phenotype. Three independent isolates were resistant or had intermediate sensitivity to nalidixic acid, sulfonamide and trimethoprim or chloramphenicol. All the isolates adhered efficiently to the two cell lines with a higher effectiveness of adherence to bladder cells. The respiratory isolates adhered more efficiently to epithelial cells than intestinal isolates. No relationship was found between antibiotic resistance phenotypes, adherence properties, and RAPD types. In conclusion, H. alvei is an unusual nosocomial pathogen with little acquired antibiotic resistance able to adhere to human epithelial cells from different human body compartments.