Colombia is an endemic country for carbapenemase-producing Gram negative organisms. Genes encoded the carbapenemase enzyme are widely distributed in the country both in Enterobacteriaceae and non-fermenting Gram negative bacilli. Colonized patients can readily disseminate these bacteria in hospitals. We aimed to characterize the population structure of carbapenemase-producing Gram-negative organisms in colonized and infected patients in order to evaluate the mechanisms of carbapenemase spread in hospitals located in the Antioquia region of Colombia.
We performed a descriptive study in three hospitals of Antioquia, between November 2013 and October 2015. Patients infected or colonized whit carbapenem-resistant Gram negative bacilli were included in the study, according to inclusion criteria. Isolates were characterized by standard microbiological methods and blaKPC, blaIMP, blaVIM and blaNDM were detected by PCR. Genetic relationships was established by molecular typing using rep-PCR.
Seventy five isolates were collected. Pseudomonas aeruginosa (28%) and Klebsiella pneumoniae (25%) were the most common bacteria. The most frequent carbapenemases in Enterobacteriaceae and P. aeruginosa were KPC (79%), VIM (16%) and VIM plus KPC in combination (5%) (Table 1). Only one common clonal group of carbapenemase-producing K.pneumoniae and Eschericia coli was identified in both infected and colonized patients but in the majority of cases a high degree of heterogeneity was observed. The population structure of Enterobacter cloacae and P. aeruginosa was more homogeneous harboring 4 and 5 clonal groups, respectively, shared between colonized and infected patients and between patients located in similar wards at the time of hospitalization.
The heterogeneity of the population structure of carbapenem-producing K. pneumoniae and E. coli in Colombia suggest that horizontal gene transfer caused by selective antibiotic pressure is the main mechanism of dissemination. In contrast, in P. aeruginosa and E. cloacae, transmission of successful clones is likely to play a major role in the spread of the latter two organisms. These information is key to design infection control strategies and antibiotic policies among the hospitals.
A. M. Rada,
C. Agudelo Restrepo, None
C. Capataz, None
C. Hernandez, None
C. Pallares, None
E. De La Cadena, None
M. N. Perenguez, None
A. Correa, None
C. Arias, None
M. V. Villegas, None
E. Restrepo, COLCIENCIAS: Investigator , Research support
See more of: Poster Abstract Session