Molecular Characterization of KPC-2-Producing Enterobacter cloacae Complex Isolates from Cali, Colombia

Abstract

The Enterobacter cloacae complex is an emerging opportunistic pathogen whose increased resistance to carbapenems is considered a public health problem. This is due to the loss of efficacy of beta-lactam antibiotics, which are used as the first treatment option in the management of infections caused by Gram-negative bacteria. The objective of this study was to perform the molecular characterization of 28 isolates of the E. cloacae complex resistant to cephalosporins and carbapenems isolated between 2011 and 2018 from five hospitals located in the municipality of Santiago de Cali, Colombia. Molecular detection of blaKPC, blaVIM, blaNDM and blaOXA-48-like genes was performed on these isolates and the genetic relationship between the isolates was assessed using multilocus sequence typing (MLST). Forty-three percent of the isolates carried the blaKPC-2 gene variant. MLST showed high genetic diversity among isolates, the most frequent being the sequence type ST510 with a frequency of 50%. The identification of the genes involved in carbapenem resistance and dispersing genotypes is an important step toward the development of effective prevention and epidemiological surveillance strategies in Colombian hospitals.

Novel insights related to the rise of KPC-producing Enterobacter cloacae complex strains within the nosocomial niche

“…The fact that high-risk international clones of KPC-ECC and KPC-Kp can coexist successfully within the nosocomial niche is in agreement with the steady rise of KPC-ECC observed in Argentina since 2010 (WHONET Argentina Network) and other countries like Brazil (Tavares et al, 2015), Colombia (Falco et al, 2021), USA (Annavajhala et al, 2019;Hansen, 2021), China (Jia et al, 2018), Portugal, and India (Center for Disease Dynamics, Economics & Policy). Accordingly, a decrease in KPC-ECC strains in our hospital is not expected despite the prevalence and fruitful spread of high-risk international clones of KPC-Kp ST258 and ST11.…”

“…On the other hand, E. hormaechei ST78 was identified as a high-risk clone among both extended-spectrum β-lactamase-producing ECC and CRECC ( Gomez-Simmonds et al., 2018 ; Emeraud et al., 2022 ). E. hormaechei ST45 is recognized as a high-risk clone ( Izdebski et al., 2015 ) reported in Australia ( Sidjabat et al., 2015 ), Colombia ( Falco et al., 2021 ), Chile ( Wozniak et al., 2021 ), Germany ( Heiden et al., 2020 ), Spain ( Fernández et al., 2015 ), and other countries in Europe ( Izdebski et al., 2015 ). As a whole, these results suggest that the establishment of successful high-risk clones of E. hormaechei in the nosocomial niche provides the opportunity to evolve to MDR phenotypes mediated by the acquisition and maintenance of diverse plasmids, which may have been substantial contributors to the continuous rise of CRECC.…”

“…In Argentina, carbapenem-resistant isolates rose from 10% to 32.7% in the case of K. pneumoniae and from 5% to 12% in the case of Enterobacter cloacae Complex (ECC) from 2010 until 2021 ( Red WHONET Argentina ). Accordingly, ECC has been reported as the second most common CRE in several countries ( Tavares et al., 2015 ; Jia et al., 2018 ; Annavajhala et al., 2019 ; Falco et al., 2021 ; Hansen, 2021 ), with E. cloacae and E. hormaechei being the prevalent multidrug-resistant (MDR) clinical isolates ( Annavajhala et al., 2019 ). Enterobacter hormaechei is part of the ECC together with 22 other species that are closely genotypically related, and little is known about its fitness within the nosocomial environment ( Davin-Regli et al., 2019 ).…”

Klebsiella Species and Enterobacter cloacae Isolates Harboring bla OXA-181 and bla OXA-48 : Resistome, Fitness Cost, and Plasmid Stability

“…Plasmid-borne AmpC genes usually lack genetic components required for regulation of AmpC expression, and therefore expression results from continuous transcription of the gene. Hence, as a β-lactamase that is inducible, regulation of its expression involves one of the genes ampR , which encodes a transcriptional regulator of the LysR family, ampG , which encodes a transmembrane permease, and ampD , which encodes cytosolic N -acetyl-anhydromuramyl- l -alanine amidase ( 31 , 32 ). This explains the presence of LysR immediately upstream of bla DHA-1 , as found in the 22-kb structure.…”

Clinical and molecular epidemiology of carbapenem-resistant Enterobacteriaceae in pediatric inpatients in South China

“…However, carbapenem-resistant (CR) Enterobacteriaceae (CRE) have emerged due to the widespread use of carbapenems over the past few decades and represent a threat to public health ( 2 ). Since the first identification of CR Klebsiella pneumoniae (CRKP) in 1996 in the United States, CRE has rapidly spread worldwide ( 3 – 5 ). In China, Klebsiella pneumoniae resistance to meropenem and imipenem grew from 2.9% and 3.0% in 2005 to 26.3% and 25% in 2018, an increase of more than the eightfold ( 6 , 7 ).…”