Abstract
Fluoroquinolone (FQ) agents are a potential resort to treat infection due to Enterobacteriaceae producing extended spectrum β-lactamase and susceptible to FQ. In a context of increase of non-susceptibility to carbapenems among Enterobacteriaceae, we characterized FQ resistance mechanisms in 75 Enterobacter cloacae isolates non-susceptible to ertapenem in North-Eastern France in 2012 and describe the population structure by pulsed field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST). Among them, 14.7% (12/75) carried a carbapenemase-encoding gene. Except one isolate producing VIM-1, the carbapenemase-producing isolates carried the well-known IncL/M pOXA48a plasmid. Most of the isolates (59/75) harbored at least a FQ-R determinant. qnr genes were predominant (40%, 30/75). The MLST study revealed that E. cloacae isolates’ clonality was wide [24 different sequence types (STs)]. The more widespread STs were ST74, ST101, ST110, ST114, and ST133. Carbapenem MICs were higher for E. cloacae ST74 than for other E. cloacae isolates. Plasmid-mediated quinolone resistance determinants were more often observed in E. cloacae ST74 isolates. These findings showed that (i) pOXA-48a is spreading in North-Eastern France, (ii) qnr is preponderant in E. cloacae, (iii) E. cloacae comprised a large amount of lineages spreading in North-Eastern France, and (iv) FQ as an alternative to β-lactams to treat ertapenem non-susceptible Enterobacteriaceae are compromised.
Highlights
Enterobacter cloacae complex is, together with Escherichia coli, very common human Enterobacteriaceae pathogens
Focusing on plasmid-mediated quinolone resistances (PMQR) harbored by the E. cloacae isolates, we showed that only qnr genes and aac(6’)-Ib-cr were detected. qnr genes were predominant (40%, 30/75) compared to aac(6’)-Ib-cr (23%, 17/75), (P < 0.02)
Focusing on PMQR harbored by the E. cloacae isolates, we showed that only qnr genes and aac(6’)-Ib-cr were detected. qnr genes were predominant (40%, 30/75) and qnrB was the most predominant family
Summary
Enterobacter cloacae complex is, together with Escherichia coli, very common human Enterobacteriaceae pathogens. They can be a reservoir for infection due to their intestine colonization in patients upon long-term hospitalization and antimicrobial treatment. Due to the β-lactams antibiotic intensive use, rate of Enterobacteriaceae resistant to lactams-lactams highly. FQ-resistance and MLST in E. cloacae increased these last years in French hospitals (Carbonne et al, 2013). Carbapenems are one of the last lines to treat patients infected with multidrug resistant Enterobacteriaceae. Decreased susceptibility to carbapenems represents a threat of therapeutic dead ends. Two main mechanisms lead to decrease the susceptibility to carbapenems in Enterobacteriaceae isolates: (i) production of carbapenemase or (ii) production of other β-lactamase in combination with decreased permeability (Nordmann et al, 2011)
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.
