Project description:Generation of hybrid MDR plasmids accelerated the evolution and transmission of resistance genes. In this study, we characterized a blaKPC-2- and blaIMP-4-coharboring conjugative hybrid plasmid constituted of an IncHI5 plasmid-like region, an IncFII(Yp)/IncFIA plasmid-like region, and a KPN1344 chromosome-like region from a clinical ST852-KL18 Klebsiella quasipneumoniae strain. The blaIMP-4 gene was captured by a novel integron In1965, and the blaKPC-2 gene was located on a new non-Tn4401 group I NTEKPC element. Both blaKPC-2- and blaIMP-4-containing genetic architectures were distinguished from classical structures, highlighting the constant evolution of these genetic elements. IMPORTANCE The emergence of carbapenem-resistant Enterobacterales (CRE) that coexpress serine- and metallo-carbapenemases is a severe threat to the efficacy of ceftazidime-avibactam (CZA), which has been proven to be extremely effective against KPC-producing Enterobacterales strains. Our study described the cooccurrence of KPC-2, a serine β-lactamase, and IMP-4, a metallo-β-lactamase (MBL), on a conjugative hybrid plasmid from a clinical carbapenem-resistant K. quasipneumoniae strain, and it revealed an alternative route for IncHI5 plasmid to evolve by recombining with other plasmids to form a hybrid plasmid. Moreover, this hybrid plasmid can be transferred into other Klebsiella species and stably persist during passage. The propagation of two important carbapenemase genes with a new genetic background using well-evolved plasmids in the clinical setting promotes the emergence of superbugs that require careful monitoring.
Project description:We report two KPC-producing Citrobacter freundii isolates from unrelated patients. In one case, bla KPC-2 was harbored on a novel variant of a Tn4401 transposon of an IncN plasmid conjugated together with a coresident IncA plasmid, whereas in the other one, bla KPC-3 was on a Tn4401a transposon located on an IncX3-IncA self-conjugative plasmid fusion. The interplay among plasmids carrying bla KPC and the coresident IncA plasmids offers new information on plasmids coresident within clinically relevant enterobacteria.
Project description:IntroductionThe increase in clinical Enterobacteriaceae with dual carbapenemase has become a serious healthcare concern. It is essential to characterize the transferability and potential dissemination of blaKPC-2- and blaNDM-1-coharboring carbapenem-resistant Citrobacter freundii (CRCF).MethodsFour blaKPC-2- and blaNDM-1-coharboring CRCF strains were collected from our surveillance of the prevalence of carbapenem-resistant Enterobacteriaceae. The isolates were assessed using species identification, antimicrobial susceptibility testing, conjugation assays, whole-genome sequencing, plasmid stability, and fitness costs. Clonality, genome, plasmidome, and phylogeny were analyzed to reveal potential dissemination.ResultsThree ST523 blaKPC-2- and blaNDM-1-coharboring CRCF strains, collected from the same hospital within 1 month, exhibited high homology (both identity and coverage >99%), implying clonal dissemination and a small-scale outbreak. Moreover, the blaKPC-2 and blaNDM-1 genes were coharbored on an IncR plasmid, probably generated by a blaKPC-2-harboring plasmid acquiring blaNDM-1, in these three strains. Importantly, the IncR plasmid may form a transferable hybrid plasmid, mediated by IS6100 via transposition, with another IncFII plasmid included in the same C. freundii strain. Furthermore, the blaKPC-2 and blaNDM-1 of the fourth CRCF strain are located on two different non-transferable plasmids lacking complete transfer elements. Additionally, throughout the course of the 10-day continuous passage, the genetic surroundings of blaNDM-1 in four CRCF strains were gradually excised from their plasmids after the 8th day, whereas they maintained 100% retention for blaKPC-2. Genome and plasmidome analyses revealed that blaKPC-2- or blaNDM-1-harboring C. freundii were divergent, and these plasmids have high homology to plasmids of other Enterobacteriaceae.ConclusionClonal dissemination of ST523 blaKPC-2- and blaNDM-1-coharboring CRCF strains was detected, and we first reported blaKPC-2 and blaNDM-1 concomitantly located on one plasmid, which could be transferred with mediation by IS6100 via transposition. Continued surveillance should urgently be implemented.
Project description:Klebsiella pneumoniae carbapenemase (KPC) producers are an emerging threat to global health, and the hospital water environment is considered an important reservoir of these life-threatening bacteria. We characterized plasmids of KPC-2-producing Citrobacter freundii and Klebsiella variicola isolates recovered from hospital sewage in Japan. Antimicrobial susceptibility testing, whole-genome sequencing analysis, bacterial conjugation, and transformation experiments were performed for both KPC-2 producers. The blaKPC-2 gene was located on the Tn3 transposon-related region from an IncP-6 replicon plasmid that could not be transferred via conjugation. Compared to the blaKPC-2-encoding plasmid of the C. freundii isolate, alignment analysis of plasmids with blaKPC-2 showed that the blaKPC-2-encoding plasmid of the K. variicola isolate was a novel IncP-6/IncF-like hybrid plasmid containing a 75,218-bp insertion sequence composed of IncF-like plasmid conjugative transfer proteins. Carbapenem-resistant transformants harboring blaKPC-2 were obtained for both isolates. However, no IncF-like insertion region was found in the K. variicola donor plasmid of the transformant, suggesting that this IncF-like region is not readily functional for plasmid conjugative transfer and is maintained depending on the host cells. The findings on the KPC-2 producers and novel genetic content emphasize the key role of hospital sewage as a potential reservoir of pathogens and its linked dissemination of blaKPC-2 through the hospital water environment. Our results indicate that continuous monitoring for environmental emergence of antimicrobial-resistant bacteria might be needed to control the spread of these infectious bacteria. Moreover, it will help elucidate both the evolution and transmission pathways of these bacteria harboring antimicrobial resistance. IMPORTANCE Antimicrobial resistance is a significant problem for global health, and the hospital environment has been recognized as a reservoir of antimicrobial resistance. Here, we provide insight into the genomic features of blaKPC-2-harboring isolates of Citrobacter freundii and Klebsiella variicola obtained from hospital sewage in Japan. The findings of carbapenem-resistant bacteria containing this novel genetic context emphasize that hospital sewage could act as a potential reservoir of pathogens and cause the subsequent spread of blaKPC-2 via horizontal gene transfer in the hospital water environment. This indicates that serial monitoring for environmental bacteria possessing antimicrobial resistance may help us control the spread of infection and also lead to elucidating the evolution and transmission pathways of these bacteria.
Project description:The emergence of carbapenem-resistant Klebsiella pneumoniae (CRKP) isolates in Egyptian hospitals has been reported. However, the genetic basis and analysis of the plasmids associated with carbapenem-resistant hypervirulent K. pneumoniae (CR-HvKP) in Egypt have not been presented. Therefore, we attempted to decipher the plasmid sequences that are responsible for transferring the determinants of carbapenem resistance, particularly bla NDM-1 and bla KPC-2 Out of 34 K. pneumoniae isolates collected from two tertiary hospitals in Egypt, 31 were CRKP. Whole-genome sequencing revealed that our isolates were related to 13 different sequence types (STs). The most prevalent ST was ST101, followed by ST383 and ST11. Among the CRKP isolates, one isolate named EBSI036 has been reassessed by Nanopore sequencing. Genetic environment analysis showed that EBSI036 carried 20 antibiotic resistance genes and was identified as a CR-HvKP strain: it harbored four plasmids, namely, pEBSI036-1-NDM-VIR, pEBSI036-2-KPC, pEBSI036-3, and pEBSI036-4. The two carbapenemase genes bla NDM-1 and bla KPC-2 were located on plasmids pEBSI036-1-NDM-VIR and pEBSI036-2-KPC, respectively. The IncFIB:IncHI1B hybrid plasmid pEBSI036-1-NDM-VIR also carried some virulence factors, including the regulator of the mucoid phenotype (rmpA), the regulator of mucoid phenotype 2 (rmpA2), and aerobactin (iucABCD and iutA). Thus, we set out in this study to analyze in depth the genetic basis of the pEBSI036-1-NDM-VIR and pEBSI036-2-KPC plasmids. We report a high-risk clone ST11 KL47 serotype of a CR-HvKP strain isolated from the blood of a 60-year-old hospitalized female patient from the intensive care unit (ICU) in a tertiary care hospital in Egypt, which showed the cohabitation of a novel hybrid plasmid coharboring the bla NDM-1 and virulence genes and a bla KPC-2-carrying plasmid.IMPORTANCE CRKP has been registered in the critical priority tier by the World Health Organization and has become a significant menace to public health. The emergence of CR-HvKP is of great concern in terms of both disease and treatment. In-depth analysis of the carbapenemase-encoding and virulence plasmids may provide insight into ongoing recombination and evolution of virulence and multidrug resistance in K. pneumoniae Thus, this study serves to alert contagious disease clinicians to the presence of hypervirulence in CRKP isolates in Egyptian hospitals.
Project description:PurposeTo explore the genetic characteristics of the IMP-4, NDM-1, OXA-1, and KPC-2 co-producing multidrug-resistant (MDR) clinical isolate, Citrobacter freundii wang9.MethodsMALDI-TOF MS was used for species identification. PCR and Sanger sequencing analysis were used to identify resistance genes. In addition to agar dilution, broth microdilution was used for antimicrobial susceptibility testing (AST). We performed whole genome sequencing (WGS) of the strains and analyzed the resulting data for drug resistance genes and plasmids. Phylogenetic trees were constructed with maximum likelihood, plotted using MAGA X, and decorated by iTOL.ResultsCitrobacter freundii carrying blaKPC-2, blaIMP-4, blaOXA-1, and blaNDM-1 are resistant to most antibiotics, intermediate to tigecycline, and only sensitive to polymyxin B, amikacin, and fosfomycin. The blaIMP-4 coexists with the blaNDM-1 and the blaOXA-1 on a novel transferable plasmid variant pwang9-1, located on the integron In1337, transposon TnAS3, and integron In2054, respectively. The gene cassette sequence of integron In1337 is IntI1-blaIMP-4-qacG2-aacA4'-catB3Δ, while the gene cassette sequence of In2054 is IntI1-aacA4cr-blaOXA-1-catB3-arr3-qacEΔ1-sul1. The blaNDM-1 is located on the transposon TnAS3, and its sequence is IS91-sul-ISAba14-aph (3')-VI-IS30-blaNDM-1-ble-trpF-dsbD-IS91. The blaKPC-2 is located on the transposon Tn2 of plasmid pwang9-1, and its sequence is klcA-korC-ISkpn6-blaKPC-2-ISkpn27-tnpR-tnpA. Phylogenetic analysis showed that most of the 34\u00B0C. freundii isolates from China were divided into three clusters. Among them, wang1 and wang9 belong to the same cluster as two strains of C. freundii from environmental samples from Zhejiang.ConclusionWe found C. freundii carrying blaIMP-4, blaNDM-1, blaOXA-1, and blaKPC-2 for the first time, and conducted in-depth research on its drug resistance mechanism, molecular transfer mechanism and epidemiology. In particular, we found that blaIMP-4, blaOXA-1, and blaNDM-1 coexisted on a new transferable hybrid plasmid that carried many drug resistance genes and insertion sequences. The plasmid may capture more resistance genes, raising our concern about the emergence of new resistance strains.
Project description:The complete and annotated nucleotide sequence of a 54,036-bp plasmid harboring a blaKPC-2 gene that is clonally present in Citrobacter isolates from different species is presented. The plasmid belongs to incompatibility group N (IncN) and harbors the class A carbapenemase KPC-2 in a unique genetic environment.
Project description:To date, blaNDM and blaKPC genes have been found predominantly in clinical settings around the world. In contrast, bacteria harbouring these two genes from natural environments are relatively less well studied compared to those found in clinical settings. In this study, a carbapenem-resistant Raoultella ornithinolytica strain, WLK218, was isolated from urban river sediment in Zhengzhou City, Henan Province, China. This isolate was subjected to PCR and antimicrobial susceptibility testing. PCR results showed that this isolate was positive for both the blaNDM-1 and blaKPC-2 genes. The antimicrobial susceptibility testing results showed that this isolate exhibited resistance or intermediate resistance to all the antibiotics tested except for streptomycin (susceptible) and cefepime (susceptible-dose dependent). The complete genome sequence of the WLK218 isolate was then determined by using a combination of the PacBio and Illumina sequencing technologies. The de novo assembly of the genome generated one chromosome and six plasmids. Among the six plasmids, the blaNDM-1 gene was carried on the IncX3 plasmid pWLK-NDM, while the blaKPC-2 gene was located on the untypeable plasmid pWLK-KPC. This is the first report of an environmental Raoultella ornithinolytica isolate co-harbouring the blaNDM-1 and blaKPC-2 genes.
Project description:PurposeNDM-1-producing Citrobacter portucalensis and Citrobacter freundii simultaneously occurred in a hospital. This study aims to characterize the bla NDM-1-carrying plasmids in these Citrobacter strains.MethodsCf7303, Cf7308, and Cf7313 were recovered from three patients in a teaching hospital from September 24 to October 1, 2021. Bacteria were identified by MALDI-TOF mass spectrometry, and antibiotics susceptibility tests were determined by VITEK® 2 compact system. Whole-genome sequencing (WGS) was performed using the HiSeq Illumina and QNome platform to characterize the genomes.ResultsCf7303 was identified as C. portucalensis Sequence Type 328 by WGS, and harbored two plasmids, namely pCf7303 and a novel IncFIB pNDM-Cf7303 on which antibiotic-resistant genes (bla TEM-1, bla CTX-M-14, bla NDM-1, aac (3)-IId, aadA2, fosA3, sul1, sul2, catA2, tetD, dfrA12, qacEdelta1, mph(A), and ble MBL) are located. C. freundii strain Cf7308 and Cf7313 belonged to the same Sequence Type 98. Cf7308 contained two plasmids, pCf7308, and an IncN1 pNDM-Cf7308 with homology to pNDM-BTR in E. coli and pNDM-CWH001 in C. freundii.ConclusionWe characterized a putatively novel IncFIB plasmid carrying bla NDM-1 in C. portucalensis. In addition, the closely related bla NDM-1-carrying IncN1 plasmids in E. coli and C. freundii suggest that interspecies or intraspecies horizontal transfer occurs in China.
Project description:Carbapenemase-producing Klebsiella pneumoniae emerged as a nosocomial pathogen causing morbidity and mortality in patients. For infection prevention it is important to track the spread of K. pneumoniae and its plasmids between patients. Therefore, the major aim was to recapitulate the contents and diversity of the plasmids of genetically related K. pneumoniae strains harboring the beta-lactamase gene blaKPC-2 or blaKPC-3 to determine their dissemination in the Netherlands and the former Dutch Caribbean islands from 2014 to 2019. Next-generation sequencing was combined with long-read third-generation sequencing to reconstruct 22 plasmids. wgMLST revealed five genetic clusters comprised of K. pneumoniae blaKPC-2 isolates and four clusters consisted of blaKPC-3 isolates. KpnCluster-019 blaKPC-2 isolates were found both in the Netherlands and the Caribbean islands, while blaKPC-3 cluster isolates only in the Netherlands. Each K. pneumoniae blaKPC-2 or blaKPC-3 cluster was characterized by a distinct resistome and plasmidome. However, the large and medium plasmids contained a variety of antibiotic resistance genes, conjugation machinery, cation transport systems, transposons, toxin/antitoxins, insertion sequences and prophage-related elements. The small plasmids carried genes implicated in virulence. Thus, implementing long-read plasmid sequencing analysis for K. pneumoniae surveillance provided important insights in the transmission of a KpnCluster-019 blaKPC-2 strain between the Netherlands and the Caribbean.