Presence of the KPC carbapapenemase in Klebsiella pneumoniae and Pseudomonas aeruginosa isolated from 6 hospitals in Colombia

Abstract number: P1685

Leal A.L., Saavedra S.Y., Saavedra C.H., Olarte N., Ovalle M.V., Cortes J.A., Buitrago G., Castillo J.S., Alvarez C.A.

Objective: To determine microbiological and molecular presence of the carbapenemases from isolates carbapenem-resistant K. pneumoniae and P. aeruginosa.

Methods: A total of thirty-six isolates resistant to carbapenems were sent to the laboratory, 34 isolates of K. pneumoniae from 6 hospitals of different cities (Bogota: 4 hospitals, Medellin: 1 hospital, Barranquilla: 1 hospital) and 2 isolates of P. aeruginosa from an institution the city of Tunja. The isolates were re-identificated with MicroScan and meropenem, imipenem, and ertapenem susceptibilities were determined by disk diffusion method. For detection of carbapenemases we used the modified Hodge test (using disks imipenem and ertapenem) and for detection of metallo-carbapenemases was performed double-disk synergy tests (DDSTs) using an IPM disk and an EDTA + mercaptoacetic acid (SMA) disk. The identification of genes encoding of carbapenemases KPC and metallo-carbapenemases was performed by PCR.

Results: We observed variability of resistant profiles to carbapenems. Resistance to the three carbapenems tested (23 isolates of K. pneumoniae and 1 isolate of P. aeruginosa), resistance to ertapenem and meropenem and intermediate susceptibility to imipenem (3 isolates of K. pneumoniae and 1 isolate of P. aeruginosa), resistance to ertapenem and imipenem and susceptibility to meropenem (1 isolate of K. pneumoniae), resistance to ertapenem and meropenem and susceptibility to imipenem (1 isolate of K. pneumoniae), resistance to ertapenem, intermediate susceptibility to meropenem and susceptibility to imipenem (1 isolate of K. pneumoniae) and finally resistance to ertapenem and susceptibility to meropenem and imipenem (5 isolates of K. pneumoniae). All isolates were positive for the Hodge test and no difference was observed when using a disk of imipenem and ertapenem. We founded that all isolates were negative for metallo-b-lactamases by PCR and DDST and all isolates were positive for carbapenemase KPC by PCR. Sequencing from amplification products confirmed the presence from KPC-3 in the vast majority of isolates.

Conclusions: Despite the variability in resistance profiles, all isolates were resistant to carbapenems. Our results indicate spread of KPC in isolates in different cities from Colombia. This is the fist report of KPC-3 from Colombia.