[Short communication: prevalence of extended spectrum beta-lactamases in gram negative rods: data of 2001-2004 period].

This study was undertaken to determine the prevalence of extended spectrum beta-lactamase (ESBL) production by Gram negative rods (GNRs) isolated from various clinical specimens (3.240 urine, 336 pus, 277 feces, 83 blood, 38 sputum) sent to our hospital laboratory, between 2001-2004. Of isolated bacteria 71.4% were identified as Escherichia coli, 11.1% were Klebsiella spp, 4.2% were Salmonella spp, 3.7% were Pseudomonas spp, 3.5% were Proteus spp, 2.9% were Shigella spp, 2.3% were Enterobacter spp, 0.5% were Acinetobacter spp, 0.12% of each Serratia spp, and Stenotrophomonas maltophilia, 0.1% were Citrobacter spp, and one of each Providencia spp and Pantoeae spp. (0.02%). ESBL production were screened by using the double disk synergy test. Of a total of 3.974 isolates, 269 (6.8%) were found to be ESBL producers. Klebsiella spp had the highest rate (14.3%) which was followed by Enterobacter spp (8.6%) and E.coli (6.7%). All of the S.maltophilia isolates were resistant to carbapenems. One of the Shigella spp was found to be an ESBL producer, being the first case from Turkey and the fifth from the world. There was statistically significant difference in distribution of ESBL producing isolates between hospitalized (16%) and non-hospitalized patients (5%) (p<0.01). A significant increase in ESBL production rates (from 3.8% in 2001 to 10.6% in 2004) was observed over time (p<0.05). The increasing trend (about 300% in four years) in ESBL production rates, should be considered as an indicator for expansion propensity and speed of the threat against the effective treatment of infections, and possible preventive strategies should be established.