PER-1 type beta-lactamase production in Acinetobacter baumannii is related to cell adhesion.

Background: Recently, the dissemination of ESBL (PER-1) among Acinetobacter isolates was reported in Turkish hospitals. We investigated the presence and the association of various virulence determinants in 20 Acinetobacter baumannii isolates, of which 13 were blaPER-1 positive.

Material/methods: Virulence tests were slime and hemolysin production, gelatinase and protease activity, biofilm formation, and Caco2 cell adhesion. RAPD analysis was also performed with ERIC primers.

Results: None of the strains was positive for slime or hemolysin production and gelatinase or protease activity. A total of 16 strains, five of which were PER-1 gene negative, formed a biofilm on polymer surfaces. There was no relation between the presence of the PER gene and biofilm formation. On the other hand, nine strains (all PER-1 gene positive) were positive in adhesion experiments to Caco2 cell lines. All PER-negative strains were negative for cell adhesion.

Conclusions: This study indicates the existence of a relation between PER-1 gene and cell adhesion in Acinetobacter strains.