All isolates possessed blaOxA-51-like and blaOxA-23-like. ISAba1
was found upstream of all blaOxA-23-like genes, and these
isolates were resistant to carbapenems. Three isolates
possessed the acquired blaOxA-58-like, and one isolate had
blaOxA-40-like. Eight isolates had only the gene encoding OXA-51
and in six of them the ISAba1 element was upstream of blaOxA-
51-like but only one was resistant to both carbapenems (Table I).
PFGE demonstrated the presence of three different clones.
Pulsotype 1 included 13 isolates that were emerging in the
hospital from February 2009 until December 2009, eight of
which were derived from respiratory tract infections. The same
clone included seven isolates from the second outbreak
episode in September 2010, five of them were from respiratory
tract infections. Pulsotype 2 comprised six isolates including
two from patients with SSI and three from patients with
pneumonia (one from the second outbreak). Pulsotype 3 consisted
of two isolates recovered in May 2009 from patients with
pneumonia.