Spread of Plasmids Carrying Multiple GES Variants

Abstract

e Five GES-producing Enterobacteriaceae isolates that displayed an extended-spectrum ␤-lactamase (ESBL) phenotype harbored two GES variants: GES-7 ESBL and GES-6 carbapenemase. In all isolates, the two GES alleles were located on the same integron that was inserted into an 80-kb IncM1 self-conjugative plasmid. Whole-genome sequencing suggested in vivo horizontal gene transfer of the plasmid along with clonal diffusion of Enterobacter cloacae. To our knowledge, this is the first description in Europe of clustered Enterobacteriaceae isolates carrying two GES ␤-lactamases, of which one has extended activity toward carbapenems. GES-type extended-spectrum ␤-lactamases (ESBLs) are increasingly reported in Pseudomonas aeruginosa, Acinetobacter baumannii, Escherichia coli, and Klebsiella pneumoniae (1, 2, 3). More than 27 GES variants have now been identified throughout the world (3). One feature of these enzymes is that they may modify their spectrum of hydrolysis by point mutations. GES-2 was the first described example of an ESBL that extended its spectrum of activity against carbapenems through a single point mutation (4). To date, at least 12 variants possess a substitution at position 170 and are theoretically able to hydrolyze carbapenems. Some variants also have the ability to hydrolyze cefoxitin (GES-4, GES-5, GES-6, and GES-11) and/or aztreonam (GES-9 and GES-14) (3). The bla GES genes have been essentially described as gene cassettes associated with class 1 or class 3 integrons on plasmids with different types of replicases (3, 5).Here, we describe enterobacterial isolates recovered from a Belgian hospital that harbored two variants of bla GES genes that were inserted back to back in the same integron, one coding for an ESBL and the second one coding for a carbapenemase.In May 2007, an ESBL-producing Enterobacter cloacae isolate (EB-1) was isolated from the stool sample of a two-year-old girl who was hospitalized in the pediatric surgical ward of a Belgian hospital for a follow-up after a second liver transplantation. This patient underwent a first transplantation in Israel in January 2006 and was transferred to Belgium for a second transplantation. During initial hospitalization, all of the stool samples obtained for screening of ESBL carriage remained negative. The child left the hospital in May 2006 and did not travel until rehospitalization in May 2007. One week after the first case, an ESBL-producing Citrobacter youngae isolate (EB-2), displaying a similar resistance pattern, was cultured from the urine sample of a 1-year-old girl who was hospitalized for acute pyelonephritis in the same ward. A third child, a 3-year-old boy transferred from Macedonia for a liver transplant in November 2007, was negative for ESBL carriage at admission. He was found to be colonized with ESBL-producing Enterobacteriaceae in December 2007, first with an E. cloacae isolate (EB-3) and then with another E. cloacae isolate (EB-4) and a K. pneumoniae isolate (EB-5).Antibiograms performed by disk diffusion and interpreted accord...

Plasmid evolution in carbapenemase‐producing Enterobacteriaceae: a review

“…In 2016, Cuzon and colleagues reported an L/M plasmid carrying GES‐5 and GES‐6 on the same plasmid (Table ). This plasmid harbored additional ARGs, including aadA1 and sul 1; bla GES‐5 and bla GES‐6 were located on a class 1 integron, and both sides were flanked by IS 26 and IS 6100 . This pEB‐1 plasmid was compared with other L/M plasmids, pEL60 and pNDM‐OM, and similar characteristics were observed, except that the integration site of the ARGs array was different .…”

“…This plasmid harbored additional ARGs, including aadA1 and sul 1; bla GES‐5 and bla GES‐6 were located on a class 1 integron, and both sides were flanked by IS 26 and IS 6100 . This pEB‐1 plasmid was compared with other L/M plasmids, pEL60 and pNDM‐OM, and similar characteristics were observed, except that the integration site of the ARGs array was different . In South Africa, bla GES‐5 was reported on an IncQ plasmid but still within a class 1 integron, with an additional aadA4 on an integron mobilization unit …”

Engineering a bioluminescent bioreporter from an environmentally sourced mercury‐resistantEnterobacter cloacaestrain for the detection of bioavailable mercury

“…A number of mercury‐resistant bacterial strains were isolated from Daroghawala dumping site soil, with strain DWH4 demonstrating resistance to mercury at concentration as high as 60 mg HgCl 2 l −1 . Strain DWH4 was identified as E. cloacae , which has been previously reported as a mercury‐resistant soilborne bacterium with an identified mer ‐like chromosomal gene sequence (Cuzon et al ; Mobeen and Latif ; Rahman et al ). A 527‐bp merR ‐like gene and associated promoter were subsequently identified that showed 99% similarity to merR ‐like sequences from E. agglomerans , A. calcoaciticus , P. aeruginosa and another E. cloacae strain (Fig.…”

“…RLU; relative light units. (Cuzon et al 2016;Mobeen and Latif 2016;Rahman et al 2017). A 527-bp merR-like gene and associated promoter were subsequently identified that showed 99% similarity to merR-like sequences from E. agglomerans, A. calcoaciticus, P. aeruginosa and another E. cloacae strain (Fig.…”

Hairpin Assembly Amplified Electrochemical Biosensor for Highly Sensitive and Specific Detection of DNA

“…Due to the importance of DNA as biological target, highly sensitive and specific determination of sequence‐specific DNA is crucial in clinical diagnosis, environmental monitoring, gene profiling and pathogen detection . In recent years, a variety of techniques have been used for DNA detection, such as DNA microarray , chemiluminiscence ,, colorimetry , surface plasmon resonance , electrochemistry , and so on. Among these techniques, the electrochemical techniques have received great interests owing to its superior characteristics of rapid response, low‐cost, small‐size, simple operation, and good selectivity .…”