DEL CAMPO R, GALAN JC, TENORIO C, TORRES C, BAQUERO F; Interscience Conference on Antimicrobial Agents and Chemotherapy (43rd: 2003: Chicago, Ill.).

Abstr Intersci Conf Antimicrob Agents Chemother Intersci Conf Antimicrob Agents Chemother. 2003 Sep 14-17; 43: abstract no. C1-611.

Hospital Ramon y Cajal, Madrid, Spain.

BACKGROUND: Loss of synergy between aminoglycosides (tobramycin or kanamycin) and penicillin was observed in seven Enterococcus hirae and three Enterococcus durans PFGE-unrelated strains. RESULTS: An AAC(6') enzymatic activity was detected by the radioenzymatic assay in all these isolates. The aac(6') gene was amplified with degenerated primers (designed from conserved regions of other aac(6') sequences previously published) and entirely sequenced (following an inverse-PCR strategy) in three E. hirae and two E. durans strains. Novel aac(6') genes were found in isolates from each species that were denominated aac(6')-Iih (from E. hirae) and aac(6')-Iid (from E. durans), which showed an 72% and 80% of identity with the aac(6')-Ii gene of E. faecium. Comparing amino acid sequences of aac(6')-Ii, aac(6')-Iih and aac(6')-Iid genes, degenerated primers set were designed to amplify homologue genes in other enterococcal species. In this way, aac(6')-positive amplifications were obtained in strains of the species E. mundtii, E. gallinarum, E. malodoratus and E. pseudoavium. Sequences of all these amplicons were obtained and served to identify the new genes aac(6')-Iim, aac(6')-Iig, aac(6')-Iimo, and aac(6')-Iip, respectively. Interestingly, no positive amplifications were obtained in Enterococcus faecalis strains (where beta-lactam/aminoglycoside synergy is the rule). CONCLUSIONS: aac(6')-Ii related genes are highly conserved among enterococci, with the probable exception of E. faecalis. The evolutionary biology of the genus is discussed accordingly with the aac(6') genes found in each one of the different enterococcal clusters.

Publication Types:

• Meeting Abstracts

Keywords:

• Alginates
• Aluminum Hydroxide
• Aminoglycosides
• Anti-Bacterial Agents
• Base Sequence
• Drug Combinations
• Enterococcus
• Enterococcus faecalis
• Polymerase Chain Reaction
• Sodium Bicarbonate
• alginic acid compound
• genetics

Other ID:

• GWAIDS0026025

UI: 102265649

From Meeting Abstracts