PER-1-type extended-spectrum beta-lactamase producing acinetobacter baumannii isolated from clinical specimens in Tabriz, Iran

To determine the prevalence of PER-1 gene type ESBLs producing isolates of A. baumannii in clinical specimens. During March 2008 to June 2009, a total of 100 A. baumannii isolates were recovered from clinical specimens of hospitalized patients in Imam Reza hospital in Tabriz. These isolates were subjected to susceptibility tests using five selected cephalosporins according to CLSI guidelines. Screening for ESBL production was carried out by confirmatory tests including DDST and CDM. The prevalence of PER-1 gene in these isolates was also determined by using PCR. All of A. baumannii isolates in this study were resistant at least to one of the selected cephalosporins. Sixty four percent of isolates exhibited a>5 mm zone size enhancement in the CDM test, whereas 53% of them gave positive results by DDST as ESBL producer. Collectively CD method and DDST showed 70% of A. baumannii as ESBLs producer, of which 51% had PER-1 gene. This research shows high prevalence of PER-1 gene type ESBLs producing A. baumannii isolates in Tabriz which is strong evidence for their resistance to cephalosporins