Molecular epidemiology of Acinetobacter baumannii in hospitals in the Mediterranean area using pulsed-field gel electrophoresis and sequence-based typing

Abstract number: P1672

Zarrilli R., Giannouli M., Tomasone F., Agodi A., Tsakris A., Vahaboglu H., Daoud Z., Triassi M.

Objectives: To investigate the geographical distribution and genetic relatedness of outbreak isolates of Acinetobacter baumannii recovered from the intensive care units of 18 hospitals in Greece, Italy, Lebanon, and Turkey from 1999 to 2006.

Methods: Genotyping was performed by pulsed-field gel electrophoresis (PFGE) analysis of ApaI-digested genomic DNA and sequence-based typing (ST) using outer membrane protein A (ompA), pilus assembly system protein (csuE) and blaOXA-51-like gene sequences (Turton et al., Clin Microbiol Infect, 13, 807, 2007).

Results: PFGE analysis of a collection of 30 A. baumannii strains associated with epidemic episodes occurred in four different European countries of the Mediterranean area led to the identification of 12 distinct PFGE profiles. ST analysis assigned 4 of them to ST group 1, 5 to ST group 2, and 2 to ST group 4. ST group 1 and 2 corresponded to the previously identified European clone II and I, respectively, ST group 4 has not been identified before. PFGE profile A of ST group 1 predominated, being isolated in 4 distinct hospitals in Naples, Italy, and in different hospitals of Thessaloniki, Larissa, and Serres, Greece from 2002 to 2006. Additional PFGE types of ST group 1 were isolated in Greece and Italy; PFGE types of ST group 2 were isolated in Greece, Italy, and Lebanon. The two distinct PFGE profiles belonging to ST group 4 were isolated in Thessaloniki, Greece, during 2003, and in Kocaeli, Turkey, during 2005 and 2006. Ten out of 12 PFGE profiles of A. baumannii epidemic isolates showed resistance to carbapenems. The blaOXA-58 gene was identified in 9 distinct PFGE profiles of ST groups 1, 2, and 4, and in 4 additional PFGE profiles of either sporadic or micro-epidemic A. baumannii isolates from Italy and Turkey; the blaOXA-23 gene was identified only in one epidemic-associated PFGE type of ST group 4 from Kayseri, Turkey.

Conclusions:A. baumannii epidemics occurring in Mediterranean hospitals have been sustained by the spread of distinct genotypes belonging to ST group 1, 2 and 4, one single PFGE profile of ST group 1 being particularly successful in Greece and Italy since 2002. The blaOXA-58 gene was present in the majority of carbapenem resistant genotypes.

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Location: Barcelona, Spain
Presentation type:
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