High proportion of carbapenemase producing Escherichia coli and Klebsiella pneumoniae among extended spectrum β-lactamase producers in Nigerian
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Date
2019-09
Authors
Olalekan, A
Onwugamba, F
Iwalokun, B
Mellmann, A
Becker, K
Schaumburg, F
Journal Title
Journal ISSN
Volume Title
Publisher
Journal of Global antimicrobial Resistance
Abstract
Objectives: Carbapenem-resistant Enterobacterales are a global problem, however little is known about
the burden and origin of carbapenem resistance in Africa. The objectives of this study were to determine
the proportion of carbapenem-resistant isolates among extended-spectrum β-lactamase-producing
Enterobacterales (ESBL-E), to identify the underlying mechanisms of resistance and to assess the
population structure of carbapenem-resistant isolates from Nigeria.
Methods: ESBL-E isolates (n = 175) from infections were collected at four hospitals in Lagos, Nigeria, from
July 2016 to January 2018 and were screened for carbapenem resistance using a VITEK12 automated
system. All carbapenem-resistant ESBL-E (CRE) were screened for blaKPC, blaCTX-M, blaCMY-2, blaNDM,
blaVIM, blaIMP, blaOXA-181 and blaOXA-48 genes. Genotyping of randomly selected isolates was performed by
whole-genome sequencing.
Results: The isolates included Escherichia coli (n = 113; 64.6%) and Klebsiella pneumoniae (n = 62; 35.4%). Of
the 175 ESBL-E isolates, 48 (27.4%) were resistant to carbapenems (15 E. coli and 33 K. pneumoniae). CRE
isolates carried blaNDM (n = 30; 62.5%), blaNDM + blaOXA-181 (n = 10; 20.8%), blaOXA-181 (n = 2; 4.2%) and
blaNDM + blaOXA-48 (n = 1; 2.1%); no carbapenemase gene was detected in 5 isolates (10.4%). The isolates
showed low diversity and were mainly associated with multilocus sequence typing (MLST) sequence
types ST410 for E. coli and ST395 and ST147 for K. pneumoniae.
Conclusion: Carbapenem resistance is frequent among ESBL-E in Nigeria and is mainly associated with
blaNDM. Genotyping suggested that the observed clones possibly originated from Southeast Asia.
Description
Keywords
carbapenemase-producing Escherichia coli and Klebsiella pneumoniae