Abstract
The most widely distributed blaCTX-M gene on a global scale is blaCTX-M-15. The dissemination has been associated with clonal spread and different types of mobile genetic elements. The objective of this review was to describe the genetic environments of the blaCTX-M-15 gene detected from Enterobacteriaceae in published literature from Africa. A literature search for relevant articles was performed through PubMed, AJOL, and Google Scholar electronic databases; 43 articles from 17 African countries were included in the review based on the eligibility criteria. Insertion sequences were reported as part of the genetic environment of blaCTX-M-15 gene in 32 studies, integrons in 13 studies, and plasmids in 23 studies. In this review, five insertion sequences including ISEcp1, IS26, orf447, IS903, and IS3 have been detected which are associated with the genetic environment of blaCTX-M-15 in Africa. Seven different genetic patterns were seen in the blaCTX-M-15 genetic environment. Insertion sequence ISEcp1 was commonly located upstream of the end of the blaCTX-M-15 gene, while the insertion sequence orf477 was located downstream. In some studies, ISEcp1 was truncated upstream of blaCTX-M-15 by insertion sequences IS26 and IS3. The class 1 integron (Intl1) was most commonly reported to be associated with blaCTX-M-15 (13 studies), with Intl1/dfrA17–aadA5 being the most common gene cassette array. IncFIA-FIB-FII multi-replicons and IncHI2 replicon types were the most common plasmid replicon types that horizontally transferred the blaCTX-M-15 gene. Aminoglycoside-modifying enzymes, and plasmid-mediated quinolone resistance genes were commonly collocated with the blaCTX-M-15 gene on plasmids. This review revealed the predominant role of ISEcp1, Intl1 and IncF plasmids in the mobilization and continental dissemination of the blaCTX-M-15 gene in Africa.
Highlights
The most widely distributed blaCTX-M gene on a global scale is blaCTX-M-15, especially in the enterobacterial species such as Escherichia coli, Klebsiella spp. and Salmonella enterica [1,2].The global dissemination of the blaCTX-M-15 gene has been associated with the clonal spread of E. coli O25: H4-ST131 strains and different types of mobile genetic elements (MGEs) such as insertion sequences, transposons, integrons, phage elements, and conjugative plasmids [1,2,3]
Most of the studies in this review were from human clinical settings, which suggests that blaCTX-M-15 -producing
The blaCTX-M-15 gene has been associated with the pandemic-initiating E. coli O25: H4 ST131 clone that causes both community and human healthcare infections globally [2]
Summary
The global dissemination of the blaCTX-M-15 gene has been associated with the clonal spread of E. coli O25: H4-ST131 strains and different types of mobile genetic elements (MGEs) such as insertion sequences, transposons, integrons, phage elements, and conjugative plasmids [1,2,3]. Of these MGEs, insertion sequences (IS) are of special concern because this mobile element can facilitate the independent transposition with insertion mutation and genetic rearrangements in Enterobacteriaceae [4,5,6]. ISEcp is a member of the IS1380 family and was first identified on the plasmid pST01 in E. coli strain 79 but has been globally disseminated in association with different blaCTX-M phylogenetic clusters [8]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
