blaKPC Genes Research Articles

Prevalence, Antimicrobial Resistance Patterns, and Emerging Carbapenemase-Producing Enterococcus Species from Different Sources in Lagos, Nigeria

Background: Enterococcus species present significant health risks due to their widespread presence in humans, animals, and the environment. This study examined the patterns of antimicrobial resistance (AMR) and the presence of carbapenemase-producing Enterococcus species from various sources. Methods: Between November 2023 and February 2024, 500 samples were collected in Lagos State, including 350 clinical human samples, 50 environmental samples, and 100 animal samples. The samples were processed, and Enterococcus isolates were identified and subjected to antimicrobial susceptibility tests (AST) by standard methods. Furthermore, carbapenemase (blaKPC and oxa-48) and virulence genes (gelE) were detected by real-time polymerase chain reaction (RT-PCR) methods using specific primers. Results: The overall prevalence of Enterococcus isolates was 4.6% (23/500), including 18 E. faecalis and 5 E. faecium. The source prevalence was 24% (12/50) from the environmental samples, 5% (5/100) from animal sources, and 1.7% (6/350) from the clinical samples. All Enterococcus isolates were 100% resistant to ciprofloxacin, erythromycin, imipenem, vancomycin, and ampicillin. However, 91% were susceptible to gentamicin. Six (6) distinct resistance profiles were observed, with the pattern AMP-ERY-TGC-CIP-TS-VA-CHL-AUG-MEM-IMI being the most frequent in 12 E. faecalis (4 isolates from humans, 2 from animals, and 6 from the environment). Notably, 39.1% (9/23) of multiple-drug resistant Enterococcus isolates harbored the gelE virulence gene, including seven E. faecalis (five environmental and two human) and two E. faecium from animal sources. The E. faecalis strains HB003 and HB050, from human bacteremia cases carrying gelE, were the first in Nigeria to produce blaKPC and oxa-48 carbapenemase genes. Conclusions: This study revealed the emergence of carbapenemase-producing Enterococcus species in our environment. A one-health approach and further molecular studies are essential to mitigate the spread and understand the transmission dynamics.

Occurrence of ESBL and Carbapenemase-Producing Acinetobacter baumannii Isolated from Hospitalised Patients in Lagos

The detection of Acinetobacter baumannii among patients in hospitals, particularly in the Intensive Care Unit (ICU) has been a public health challenge. This study determines the prevalence, virulence, and antimicrobial-resistant determinants in extended-spectrum beta-lactamase (ESBL) and carbapenemase-pro¬ducing A. baumannii from critically ill patients. Between April 2022 and March 2023, 530 samples compris¬ing 270 from Category-A (ICUs) and 260 from Category-B (non-ICU) patients attending referral hospitals in Lagos were collected. The samples were analyzed and antibiotic susceptibility testing was performed by standard methods. RT-PCR was used to detect resistance and virulence gene markers. Sixteen A. bauman¬nii isolates were identified based on the possession of blaOXA-51-like intrinsic gene, and 93.75(15/16) isolates with OmpA virulence gene. The prevalence of 1.92% and 4.07% A. baumannii was recorded for categories A and B patients, respectively. There was no statistically significant relationship between A. baumannii detections, gender, and age. A. baumannii isolates were 93.75% susceptible to gentamicin, 87.50% piper¬acillin-tazobactam, and 75% trimethoprim-sulfamethoxazole. All the isolates were 100% resistance to ce¬fotaxime and 75% resistance to cefepime and carbapenem. Most isolates from the two categories harbored at least one of the Carbapenemase genes (blaKPC, blaIMP, and blaOXA-48) or ESBL-encoding genes (blaTEM and blaSHV) genes evaluated. Interestingly, two strains from category-A patients, LAB050 and LAU060C that harbored blaKPC and blaOXA-48 and blaSHV, developed resistance to piperacillin-tazobactam, and exhibited resistant profile CTX-TZP-CIP-CAZ-CRO-FEP-FOX-MEM-IMI-DOR. This study revealed emerging A. baumannii strains with the co-existence of ESBL and carbapenemase genes. Constant surveillance, early detection, and antibiotic stewardship are crucial to mitigate the spread.

Investigating the broad clonal diversity of β-lactamases producing Enterobacteriaceae strains recovered from bloodstream infection in five hospitals

Background: Detecting β-lactamases-producing Enterobacteriaceae is underestimated due to difficulties in clinical laboratory procedures. Objectives: Identify β-lactamases in Enterobacteriaceae recovered from bloodstream infection patients in five different hospitals. Methods: Phenotypic and genetic methods were used. PCR were used to detect blaTEM, blaSHV, blaCTX-M, blaGES, blaAmpC, blaCMY, blaFOX, blaDHA, blaKPC and blaNDM genes and ERIC-PCR investigated the genetic diversity. Findings: K. pneumoniae, Enterobacter cloacae complex, Enterobacter aerogenes, and Escherichia coli were recovered. ESBL production was detected in 56.8% (Double-Disk Synergy Test) and 55.6% (Etest) of all strains. Modified Hodge Test was positive for K. pneumoniae (39.2%) and Enterobacter spp. (11.1%). ESBL genes were observed in 79.5% of all strains, blaTEM in 61.3% and blaSHV in 42%. The simultaneous presences of ESBL-encoding genes were observed (37.5%). The gene blaKPC was detected in 45% of K. pneumoniae and 18.5% of Enterobacter strains. Main conclusions: Phenotypic and molecular tests detected several types of β-lactamases among the bacterial strains recovered. The obtained results also suggest that several clonal populations circulate among hospitals, and some strains were genetically identical, showing that cross infection practices must be used for all patients, in all healthcare services.

Assessment of the Diagnostic Accuracy of the Modified Hodge Test and Modified Carbapenem Inactivation Method for Identifying Carbapenem Resistance Mechanisms in Klebsiella pneumoniae: A Whole Genome Sequencing-Based Exploratory Study.

Carbapenem-resistant Klebsiella pneumoniae (CRKP) is a major public health concern, particularly in immunocompromised and critically ill patients. Colistin and tigecycline are among the last-resort treatment options, while the primary driver of CRKP emergence is carbapenemase production, especially Klebsiella pneumoniae carbapenemase (KPC) and metallo-β-lactamase (MBL). A thorough understanding of its resistance mechanisms is essential for selecting the most effective antimicrobial therapy. This study aimed to evaluate the diagnostic accuracy of the modified Hodge test (MHT) and modified carbapenem inactivation method (mCIM) in detecting molecular resistance mechanisms in CRKP clinical isolates. This exploratory study consisted of 65 CRKP isolates, which were identified using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) (Bruker Daltonik GmbH, Bremen, Germany). Antimicrobial susceptibility testing was performed using the BD Phoenix system. The test isolates were subjected to MHTand mCIMand later shipped to the Central Research Laboratory (CRL), Bengaluru, India, where they were subjected to polymerase chain reaction (PCR) and whole-genome sequencing (WGS). PCR detected blaOXA-48-like , blaNDM-1 , bla NDM-5, and blaKPC genes in 79.7%, 10.2%, 64.4%, and 1.7% CRKP isolates, respectively. The PCR results were concordant with WGS. The MHTdemonstrated an overall sensitivity of 60.3%, specificity of 100%, positive predictive value (PPV) of 100%, and negative predictive value (NPV) of 4.2% for detecting carbapenemase production. It showed the highest sensitivity and specificity for blaKPC (100%) and blaOXA-48-like (75%) genes, respectively, with the highest PPV for blaOXA-48-like (91.4%) and NPV for blaKPC (100%). However, agreement between MHT and PCR for carbapenemase detection was negligible (Kappa: 0.049, p=0.223). A minimal but statistically significant agreement was noted for blaOXA-48-like detection (Kappa: 0.314, p=0.007), while no significant agreement was observed for blaNDM-1 , blaNDM-5 , or blaKPC genes. The mCIMhad an overall sensitivity of 3.63%, specificity of 100%, PPV of 100%, and NPV of 1.8%. It exhibited the highest sensitivity (4.3%) and specificity (100%) for blaOXA-48-like genes, with the highest PPV for blaOXA-48-like (100%), and NPV for blaKPC (98.1%). No statistically significant agreement was found between mCIM and PCR for carbapenemase detection (Kappa: 0.001, p=0.850). Comprehensive assessment of the diagnostic accuracy of MHT and mCIM using WGS across a broad spectrum of multi-drug-resistant (MDR) organisms should be conducted at multiple centers to produce reliable data that can guide better clinical management of the patients.

Carbapenem-resistant Morganella morganii carrying blaKPC-2 or blaNDM-1 in the clinic: one-decade genomic epidemiology analysis.

Currently, infections attributable to carbapenem-resistant Morganella morganii (CRMM) isolates harboring blaKPC or blaNDM are on the rise, highlighting the increasing severity of acquired antimicrobial resistance. However, systematic phylogeographic and genetic characterization of these isolates worldwide is still lacking. In this study, we elucidated the spatial-temporal distribution and evolutionary trajectory of blaKPC and blaNDM genes within their core genetic environments. We emphasize the necessity of strengthening surveillance and controlling these organisms in clinical settings to prevent the generation of so-called "superbug" isolates.

Evaluating the Performance of Two Rapid Immunochromatographic Techniques for Detecting Carbapenemase in Carbapenem-Resistant Enterobacterales Clinical Isolates.

The rapid and accurate identification of carbapenemases in Enterobacterales isolates is of paramount importance for the selection of effective antibiotics and the control of hospital-acquired infections. This study aimed to evaluate the performance of two immunochromatographic methods, NG-Test Carba 5 (Carba 5) and Goldstream Carbapenem-resistant K.N.I.V.O. Detection K-Set (K-Set) for detecting five major carbapenemase (KPC, NDM, IMP, OXA-48-like, and VIM). Carbapenemase genes were confirmed by PCR. In this study, a total of 245 carbapenem-resistant Enterobacterales (CRE) isolates were encompassed, with an overwhelming 96.7% of these strains exhibiting the ability to produce carbapenemase. A total of 58.2% of Klebsiella pneumoniae strains that produce KPC carbapenemase were the most prevalent among carbapenem-resistant Enterobacteriaceae (CRE). NDM-producing Klebsiella pneumoniae accounted for 30.4%. Importantly, NDM-type carbapenemase emerges as the predominant form in Escherichia coli and Enterobacter cloacae strains, accounting for 46 (93.9%) and 20 (83.3%) cases, respectively. The performance of the two methods in carbapenemase detection has demonstrated remarkable outcomes, exhibiting overall specificity and sensitivity exceeding 99%. Specifically, the K-Set accurately detected a unique KPC-carbapenemase in K. pneumoniae, whereas Carba 5 was unable to identify it. This was due to the presence of a novel bla KPC gene, which harbored a specific point mutation (A to G) at nucleotide position 787, differentiating it from the bla KPC-33 gene. These two methods, characterized by their simplicity, rapidity, and accuracy, are ideally suited for detecting carbapenemases in routine microbiology laboratories. They serve as a vital foundation for the rational selection of antibiotics in clinical practice.

Plasmidome analyses of Klebsiella pneumoniae co-producing blaKPC-2 and blaNDM-1 in Southern Brazil: characterisation of mobile genetic elements.

Plasmidome analyses of Klebsiella pneumoniae co-producing blaKPC-2 and blaNDM-1 in Southern Brazil: characterisation of mobile genetic elements.

Characterization of a Multidrug-Resistant Hypovirulent ST1859-KL35 Klebsiella quasipneumoniae subsp. similipneumoniae Strain Co-harboring tmexCD2-toprJ2 and blaKPC-2.

Characterization of a Multidrug-Resistant Hypovirulent ST1859-KL35 Klebsiella quasipneumoniae subsp. similipneumoniae Strain Co-harboring tmexCD2-toprJ2 and blaKPC-2.

Whole-genome sequencing characterisation of a new KPC-245 variant-carrying Klebsiella pneumoniae strain isolated from a transplanted patient and resistant to ceftazidime/avibactam, meropenem/vaborbactam and imipenem/relebactam.

Whole-genome sequencing characterisation of a new KPC-245 variant-carrying Klebsiella pneumoniae strain isolated from a transplanted patient and resistant to ceftazidime/avibactam, meropenem/vaborbactam and imipenem/relebactam.

Epidemiology, phylogeny and genetic characterization of carbapenem-resistant Citrobacter spp. from 5 hospitals in China.

Epidemiology, phylogeny and genetic characterization of carbapenem-resistant Citrobacter spp. from 5 hospitals in China.

Characterization of a novel KPC-2 variant, KPC-228, conferring resistance to ceftazidime-avibactam in an ST11-KL64 hypervirulent Klebsiella pneumoniae.

Characterization of a novel KPC-2 variant, KPC-228, conferring resistance to ceftazidime-avibactam in an ST11-KL64 hypervirulent Klebsiella pneumoniae.

Geographic variations in distributions of carbapenemase-encoding genes, susceptibilities, and minimum inhibitory concentrations of inpatient meropenem-resistant Enterobacterales to ceftazidime-avibactam, meropenem-vaborbactam, and aztreonam-avibactam across four global regions: 2020-2022 Data from the Antimicrobial Testing Leadership and Surveillance.

Geographic variations in distributions of carbapenemase-encoding genes, susceptibilities, and minimum inhibitory concentrations of inpatient meropenem-resistant Enterobacterales to ceftazidime-avibactam, meropenem-vaborbactam, and aztreonam-avibactam across four global regions: 2020-2022 Data from the Antimicrobial Testing Leadership and Surveillance.

Evaluation of Xpert® Carba-R Assay Performance from FecalSwab™ Samples.

Background/Objectives: The emergence and spread of carbapenemase-producing Enterobacterales (CPE) represents a significant challenge prompting the need to optimize diagnostic tools to detect CPE carriers. The Xpert® Carba-R assay (Cepheid, Sunnyvale, CA, USA), a Real-Time PCR-based test, can detect the blaKPC, blaVIM, blaOXA-48, blaNDM and blaIMP carbapenemase genes directly from rectal swabs. This study assessed the performance of the Xpert® Carba-R assay using FecalSwab™ (Copan, Brescia, Italy), a liquid-based collection device. Methods: The first part of the study aimed to establish the FecalSwabTM volume which gave the most similar Ct values to those obtained by the Transystem™ double swab (Copan). The best volume was then used to assess the limit of detection (LoD) for each target and compare the accuracy of different FecalSwabTM storage conditions (room temperature or 4 °C after 16 h compared to T0). Results: The results indicated that using 200 µL of the FecalSwab™ medium provided reliable Ct values, with the lowest number of invalid samples compared to traditional methods. The average LoDs for different carbapenemases ranged from 4.7 × 103 to 6.8 × 103 CFU/mL. FecalSwab™ showed a better performance after 16 h at room temperature compared to storage at 4 °C. Conclusions: This study supports single sampling with the FecalSwab™ medium for both molecular and cultural methods, for the potential optimization of CPE screening.

Whole-Genome Sequencing of Extended-Spectrum β-Lactamase-Producing Klebsiella pneumoniae Isolated from Human Bloodstream Infections.

Klebsiella pneumoniae is a Gram-negative bacterium commonly associated with bloodstream infections (BSIs), which can lead to severe clinical outcomes, especially in immunocompromised individuals or patients with underlying health conditions. The increasing prevalence of K. pneumoniae that produces extended-spectrum β-lactamases (ESBL) poses a significant challenge for treatment and infection control, necessitating a swift diagnostic approach and tailored antimicrobial therapy to improve patient outcomes. A total of 32 K. pneumoniae isolates were recovered from BSIs from December 2021 to August 2022. Whole-genome sequencing (WGS) was performed on the 14 ESBL-producing isolates. All ESBL isolates carried the blaCTX-M-15 gene, together with other β-lactamase-encoding genes (blaTEM-1, blaSHV-28, blaSHV-26, or blaOXA-1). Three of the isolates also carried the blaKPC-3 gene. Resistance genes to quinolones, sulfonamides, tetracycline, aminoglycosides, and chloramphenicol were also detected. We can conclude that the presence of ESBL-producing isolates among K. pneumoniae of BSIs raises concerns, since these enzymes limit the available treatment options, and future research must include studies on alternative therapies for dealing with resistant bacterial infections and developing new approaches to disease treatment.

Genomic Insights into Colistin and Tigecycline Resistance in ESBL-Producing Escherichia coli and Klebsiella pneumoniae Harboring blaKPC Genes in Ecuador.

Introduction: Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) are resistant to third-generation cephalosporins (3GCs), carbapenems, colistin, and tigecycline, making them a major public health priority, mainly within the developing world. However, their genomic epidemiology and possible determinants of resistance remain to be elucidated. Thus, this study aimed to perform a genomic characterization of E. coli and K. pneumoniae, both of which are resistant to last-line antibiotics, isolated from humans, poultry, and a dairy farm environment within Ecuador. Methods: This study analyzed nine 3GC-resistant E. coli isolates harboring the mcr-1 gene (six from poultry farms, two from human infections, and one from dairy farm compost), together with ten isolated colistin- and carbapenem-resistant K. pneumoniae clinical samples. Results: The E. coli isolates of human origin belonged to ST609 and phylogroup A, while the poultry and compost isolates belonged to phylogroups A, B1, E, and F. Diverse STs of the K. pneumoniae isolates included ST13 (five isolates), ST258 (four isolates), and ST86 (one isolate). Within the E. coli isolates, blaCTX-M-55, blaCTX-M-65, blaCTX-M-15, and blaCTX-M-2 genes were identified. This study also identified blaCMY-2 and blaKPC-3 (the latter in a carbapenem-susceptible isolate). In E. coli, the plasmid-borne mcr-1.1 gene was identified across all E. coli isolates within an IncI2 plasmid. Tigecycline-reduced susceptibility or resistance was related to missense amino acid substitutions coded in the marA and acrA genes. Within K. pneumoiae, blaCTX-M-15 and blaCTX-M-65, on the one hand, and blaKPC-2 and blaKPC-3, on the other, were associated with 3GC and carbapenem resistance, respectively. The blaKPC-2 allele was identified in a ~10 kb Tn4401 transposon (tnpR-tnpA-istA-istB-blaKPC-2-tnpA). In K pneumoniae, sequence data and phenotypic analysis linked a nonsense amino acid substitution coded in the mgrB (K3*) gene and missense amino acid substitutions coded in the marA, acrA, arnB, eptA, pmrB, pmrJ, and phoQ genes to colistin resistance. Meanwhile, tigecycline resistance was linked to nonsense and missense amino acid substitutions coded within the ramR sequence. Additionally, this study identified several integron structures, including Int191 (5'CS-dfrA14-3'CS), which was the most prevalent integron (Int) among E. coli and K. pneumoniae isolates in this study, followed by Int0 (5'CS-3'CS) and Int18 (5'CS-dfrA1-3'CS). Conclusions: These results contribute to the genomic epidemiology of MDR E. coli and K. pneumoniae in our setting and to the worldwide epidemiology in the One Health approach.

An Unusual 'Gift' from Humans: Third-Generation Cephalosporin-Resistant Enterobacterales in migratory birds along the East Asian-Australasian Flyway.

An Unusual 'Gift' from Humans: Third-Generation Cephalosporin-Resistant Enterobacterales in migratory birds along the East Asian-Australasian Flyway.

Emergence and clonal dissemination of KPC-2- and NDM-1-coharboring Citrobacter freundii in China with an IncR plasmid.

The rise of carbapenem-resistant Enterobacteriaceae coharboring KPC-2 and NDM-1 poses a significant public health threat. KPC-2-NDM-1-Citrobacter freundii is rarely reported in clinical settings. In this study, we report the largest cohort of eight KPC-2-NDM-1-C. freundii isolated from children with urinary tract infections. Comprehensive characterization, including antimicrobial susceptibility testing, plasmid conjugation, whole-genome sequencing, and comparative genomics, was conducted for these clinical strains. Antimicrobial susceptibility testing indicated that all strains were resistant to meropenem [minimal inhibitory concentration (MICs) ≥ 8 µg/mL] and imipenem (MICs > 8 µg/mL). Genotyping and comparative genomics analyses identified the eight KPC-2-NDM-1- C. freundii belonging to ST523, exhibiting a close relationship characterized by 45 single nucleotide polymorphisms. Whole-genome sequencing and plasmid analysis confirmed the presence of blaKPC-2 and blaNDM-1 on an IncR plasmid named pC275-2 with 46,050 bp. The blaNDM-1 was integrated within the blaNDM-1 related region, which includes ΔISAba125, blaNDM-1, ble-MBL, trpF, dsbD, and ISCR1, while the blaKPC-2 gene was located on a novel non-Tn4401 genetic element. The blaKPC-2 genetic architectures containing blaKPC-2 differed from classical structures, underscoring the ongoing evolution of these genetic elements.IMPORTANCEOur study described the largest cohort to date of eight ST523 KPC-2-NDM-1-C. freundii isolated from children with urinary tract infections. The cooccurrence of KPC-2, a serine β-lactamases, and NDM-1, a metallo-β-lactamase on an IncR plasmid pC275-2 from a clinical carbapenem-resistant C. freundii. The conserved insertion structure mediated the blaNDM-1, and the propagation of blaKPC-2 gene with a new genetic background using IncR plasmid in clinical settings promotes the emergence of superbugs necessitating vigilant monitoring. Our research detected that ST523 KPC-2- NDM-1-C. freundii were disseminated in a children's hospital. The potential spread of an IncR plasmid within the hospital raises concerns about the pandemic potential of this clone that produces two carbapenemases: KPC-2 and NDM-1. Further investigations will be necessary to control and prevent the spread of KPC-2-NDM-1-C. freundiis.

Prevalence of β-lactam antibiotic resistance of Escherichia coli isolated from a neonatal intensive care unit

IntroductionEscherichia coli (E. coli) causes infections in neonates admitted to neonatal intensive care units (NICUs). Although β-lactam antibiotics are commonly used for neonatal infectious diseases, E. coli has exhibited resistance to them. Therefore, we investigated the resistance of E. coli strains isolated from a NICU to β-lactam antibiotics.MethodsE. coli isolates were collected from patients admitted to a NICU from 2020–2023. The clinical characteristics of the patients were analyzed. The antimicrobial susceptibility was determined using the agar dilution method, and the distribution of β-lactamase genes was analyzed using PCR. Conjugation experiments were conducted to analyze the horizontal transferability of resistance genes on plasmids. Genomic DNA was extracted for whole genome sequencing, construction of plasmid physical maps, locating resistance genes, and analyzing flanking regions and the resistance gene-related sequences.ResultsThroughout the study period, 110 distinct E. coli strains were collected. Among these, 62 cases presented strains, which were resistant against at least one of seven ß-lactam antibiotics associated with conditions such as ventilator-associated pneumonia (35/62), catheter-associated urinary tract infection (14/62), necrotizing enterocolitis (7/62), skin infection (1/62), and neonatal septicemia (5/62). Resistance of E. coli isolates to seven β-lactam antibiotics ranged from 2.73–56.36%. In 62 strains (56.36%, 62/110), six genotypes (11 sub-genotypes) of 111 β-lactamase genes were identified. Conjugation experiments revealed two transconjugants carrying the blaKPC-2 gene and two carrying the blaOXA-1 gene, exhibiting resistance to carbapenems and other β-lactams. The plasmids of four strains were successfully conjugated and transferred to recipient E. coli C600. PCR of the transconjugant resistance genes revealed that two carried a blaKPC-2 gene with a MIC increased up to 32-fold relative to the recipients, and the other two carried a blaOXA-1 gene with a 32-fold increased MIC. For isolate ECK03 carrying blaKPC-2, blaCTX-M-64, blaCTX-M-65, and blaTEM-1, sequencing results showed that blaKPC-2, blaCTX-M-64, and blaTEM-1 were harbored on a 114-kb pECK03_KPC-2 plasmid, whereas two identical blaCTX-M-64 genes were harbored in E. coli isolate ECF13. ConclusionThese findings highlight the existence of E. coli β-lactam resistance within NICU populations, emphasizing the need for continual monitoring of β-lactamase isolates to facilitate effective antibiotic selection.

Double carbapenemases in Klebsiella pneumoniae blood isolates: dissemination in a single medical center via multiple plasmids and a variety of highly efficient clones.

Acquisition of multiple carbapenemase genes by Klebsiella pneumoniae (Kp) is an emerging public health threat. Here, we aim to elucidate the population structure of Kp blood isolates carrying two different carbapenemase genes and identify the mechanism facilitating their dissemination. The study was conducted in a tertiary healthcare center between 2014 and 2022. Twenty-four patients with bacteremia caused by Kp carrying two different carbapenemase genes were identified. All 24 blood isolates were analyzed by short-read genome sequences supplemented by long reads in a selected number of isolates. All isolates carried blaKPC (23 blaKPC-2, 1 blaKPC-3) and blaVIM-1 genes, along with a variety of antimicrobial resistance determinants. The isolates were clustered in six clonal lineages (ST39, ST147, ST323, ST258, ST3035, and ST340). Long-read genome sequences demonstrated that each carbapenemase gene was located in a separate group of plasmids: the blaKPC-2 on a fusion of IncFIB(pQil) and IncFII(K) plasmids, the blaKPC-3 on IncX3, the blaVIM-1 on IncC, or a fusion of the IncFIB(pNDM-Mar) and IncHI1B(pNDM-MAR) plasmids. Comparison of plasmid content of eight isolates carrying a single carbapenemase gene from a previous study with eight isolates carrying two carbapenemase genes from the present study, matched by clonal lineages, revealed that the second carbapenemase gene was acquired by addition of another plasmid. Identical plasmids were found within the same lineage and across lineages. These findings suggest that dissemination of carbapenemase genes in our hospital setting was driven by multiple plasmids across a variety of highly efficient clones.

Distribution of beta-lactamase genes in Enterobacteriaceae from human clinical samples.

Distribution of beta-lactamase genes in Enterobacteriaceae from human clinical samples.