Evolution of antimicrobial resistance in Gram negative bacilli from intensive care units in Colombia

Abstract

Introduction: The continuous evolution of antimicrobial resistance poses a major threat to public health worldwide. Molecular biology techniques have been integrated to epidemiological surveillance systems to improve the control strategies of this phenomenon.

Objective: To describe the phenotypic and molecular profiles of the most important Gram negative bacilli from intensive care units in 23 Colombian hospitals during the study period 2009-2012.

Materials and methods: A descriptive study was conducted in 23 hospitals belonging to the Colombian Nosocomial Resistance Study Group. A total of 38.048 bacterial isolates were analyzed using WHONET over a four-year period. The antimicrobial resistant profiles were described for Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii. Polymerase chain reaction was performed in 1.248 strains to detect the most clinically relevant carbapenemases.

Results: Escherichia coli was the most frequently isolated organism (mean=14.8%). Frequency of K. pneumoniae increased significantly from 11% in 2009 to 15% in 2012 (p<0.001). All screened isolates had rising trends of multidrug-resistant profiles. KPC (Klebsiella pneumoniae carbapenemase) 

was detected in 68.4% of K. pneumoniae isolates while VIM (Verona integron-encoded metallo-betalactamase) was present in 46.5% of them.
Conclusion: In this study, an increase in the trend of multidrug-resistant organisms and a wide distribution of carbapenemases was observed. The integration of molecular biology to surveillance systems allowed the compilation of this data, which will aid in the construction of guidelines on antimicrobial stewardship for prevention in Colombia.