Whole genome characterization of Trichophyton indotineae isolated in Singapore.

Complete genome sequences from two Trichophyton indotineae isolates were obtained from a 23-year-old male presenting with tinea cruris after an overseas recreational water exposure and from a 53-year-old female patient with unknown travel history. Analysis of the squalene epoxidase gene and the cyp51 gene family showed an absence of mutations, correlating with phenotypic drug susceptibility. The Single Nucleotide Polymorphisms (SNPs) distance between both isolates was 92. Within the T. indotineae cluster, SNPs ranged from 7 to 182, suggesting a high genetic relatedness with other South Asian isolates. This study suggests that the prevalence of T. indotineae is under-reported and more widespread than previously thought.

Trichophyton indotineae, is a fungus causing difficult to treat ringworm infections. Two isolates were sequenced and their relationship and to other isolates was characterized. We also studied the genes responsible for first-line antifungal treatment.

A hydrophilic polyimidazolium antibiotic targeting the membranes of Gram-negative bacteria.

OBJECTIVES: The rise of MDR Gram-negative bacteria (GNB), especially those resistant to last-resort drugs such as carbapenems and colistin, is a global health risk and calls for increased efforts to discover new antimicrobial compounds. We previously reported that polyimidazolium (PIM) compounds exhibited significant antimicrobial activity and minimal mammalian cytotoxicity. However, their mechanism of action is relatively unknown. We examined the efficacy and mechanism of action of a hydrophilic PIM (PIM5) against colistin- and meropenem-resistant clinical isolates. METHODS: MIC and time-kill testing was performed for drug-resistant Escherichia coli and Klebsiella pneumoniae clinical isolates. N-phenyl-1-naphthylamine and propidium iodide dyes were employed to determine membrane permeabilization. Spontaneous resistant mutants and single deletion mutants were generated to understand potential resistance mechanisms to the drug. RESULTS: PIM5 had the same effectiveness against colistin- and meropenem-resistant strains as susceptible strains of GNB. PIM5 exhibited a rapid bactericidal effect independent of bacterial growth phase and was especially effective in water. The polymer disrupts both the outer and cytoplasmic membranes. PIM5 binds and intercalates into bacterial genomic DNA upon entry of cells. GNB do not develop high resistance to PIM5. However, the susceptibility and uptake of the polymer is moderately affected by mutations in the two-component histidine kinase sensor BaeS. PIM5 has negligible cytotoxicity on human cells at bacterial-killing concentrations, comparable to the commercial antibiotics polymyxin B and colistin. CONCLUSIONS: PIM5 is a potent broad-spectrum antibiotic targeting GNB resistant to last-resort antibiotics.

Dominant Carbapenemase-Encoding Plasmids in Clinical Enterobacterales Isolates and Hypervirulent Klebsiella pneumoniae, Singapore.

Dissemination of carbapenemase-encoding plasmids by horizontal gene transfer in multidrug-resistant bacteria is the major driver of rising carbapenem-resistance, but the conjugative mechanics and evolution of clinically relevant plasmids are not yet clear. We performed whole-genome sequencing on 1,215 clinical Enterobacterales isolates collected in Singapore during 2010-2015. We identified 1,126 carbapenemase-encoding plasmids and discovered pKPC2 is becoming the dominant plasmid in Singapore, overtaking an earlier dominant plasmid, pNDM1. pKPC2 frequently conjugates with many Enterobacterales species, including hypervirulent Klebsiella pneumoniae, and maintains stability in vitro without selection pressure and minimal adaptive sequence changes. Furthermore, capsule and decreasing taxonomic relatedness between donor and recipient pairs are greater conjugation barriers for pNDM1 than pKPC2. The low fitness costs pKPC2 exerts in Enterobacterales species indicate previously undetected carriage selection in other ecological settings. The ease of conjugation and stability of pKPC2 in hypervirulent K. pneumoniae could fuel spread into the community.

Azithromycin-Resistant Salmonella enterica Serovar Typhi AcrB-R717Q/L, Singapore.

Global travel has led to intermittent importation of multidrug-resistant Salmonella enterica serovar Typhi into industrialized countries. We detected azithromycin-resistant Salmonella Typhi in Singapore, of which 2 isolates were likely locally acquired. Ongoing vigilance and surveillance to minimize the public health risk for this serious pathogen is needed.

Genomic Characterization of Klebsiella quasipneumoniae from Clinical Specimens in Singapore.

A total of 1,281 specimens from 1,024 patients were screened. Phylogenetic analysis classified 44 of these isolates as Klebsiella quasipneumoniae subsp. similipneumoniae (44/1,281 [3.4%]) and the remaining three as K. quasipneumoniae subsp. quasipneumoniae. The most common specimen source was urine (21/47 [44.7%]) followed by blood (14/47 [29.8%]). K. quasipneumoniae isolates were nonclonal. Carbapenemase-encoding genes (blaNDM and blaOXA-181) were detected in only two isolates (2/47 [4.3%]). K. quasipneumoniae appears to cause a spectrum of infections similar to those of K. pneumoniae, although higher rates of susceptibility to many commonly tested antimicrobials and low prevalence of virulence genes were demonstrated.

In vitro susceptibility of Mycobacterium abscessus complex and feasibility of standardizing treatment regimens.

OBJECTIVES: To determine the in vitro susceptibility of members of the Mycobacterium abscessus complex to routinely tested antibiotics and to an extended antibiotic panel. METHODS: Non-duplicate isolates for which susceptibility testing results were available were included in this study. Retrospective laboratory records were reviewed, including tigecycline susceptibility results, and testing was performed with additional drugs, including vancomycin, dalbavancin, telavancin, oritavancin, rifabutin, delafloxacin, eravacycline, clofazimine and bedaquiline using broth microdilution (Sensititre, Thermo Fisher). RESULTS: A total of 218 M. abscessus complex isolates were included for retrospective review, of which 151 were respiratory isolates. Of these 218 isolates, 211 were available for additional testing with the extended antibiotic panel. Of these, 146 were respiratory isolates. One isolate had a vancomycin MIC of 2 mg/L and MICs of all other isolates were >8 mg/L. All isolates had MICs of >8 mg/L for oritavancin, dalbavancin and telavancin. One isolate had a delafloxacin MIC of 4 mg/L and MICs of all other isolates were >8 mg/L. The MIC50/MIC90s of rifabutin, tigecycline, eravacycline, clofazimine and bedaquiline were 16/32, 0.5/1, 0.12/0.25, 0.12/0.25 and 0.06/0.12 mg/L, respectively. CONCLUSIONS: In vitro activity was demonstrated for clofazimine, bedaquiline and eravacycline, indicating potential for inclusion as standardized therapy for M. abscessus complex infections.

Staphylococcus singaporensis sp. nov., a new member of the Staphylococcus aureus complex, isolated from human clinical specimens.

Staphylococcus argenteus and Staphylococcus schweitzeri are the newest members of the Staphylococcus aureus complex. The number of clinical reports attributed to these new S. aureus complex members is limited. In a retrospective clinical laboratory study conducted over a 4-month period investigating the prevalence of S. argenteus and S. schweitzeri, a total of 43 isolates were selected. Phylogeny based on core-gene multilocus sequence typing (MLST) analysis confirmed that 37 were S. argenteus but a genetically distinct clade of six isolates was identified. Digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) analyses further supported the classification of these six isolates as a separate species. When compared to S. aureus complex reference genomes, the ANI values were ≤94 % and the dDDH values were <53 %. Based on the seven-gene S. aureus MLST scheme, the six isolates belong to five novel allelic profiles (ST6105, ST6106, ST6107, ST6108 and ST109). Their clinical infection features were similar to S. aureus. Skin and soft tissue infections presented in four out of the six cases. Routine clinical diagnostic identification using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and biochemical profiling does not differentiate these new members from the rest of the complex. Genotypic analysis suggests that the six isolates belong to a novel species, Staphylococcus singaporensis sp. nov. with isolate SS21T (=DSM 111408T=NCTC14419T) designated as the type strain.

First isolation of Candida oceani from a clinical specimen.

We describe to our knowledge, the first documentation of Candida oceani isolate from human skin punch biopsy. Susceptibility testing was performed using Sensititre YeastOne YO10 microplate method and all common clinical antifungals appeared to have good activity against the isolate. Whole genome sequencing was also performed to provide a C. oceani draft genome.

Oral vs Intravenous Antibiotics for Patients With Klebsiella pneumoniae Liver Abscess: A Randomized, Controlled Noninferiority Study.

BACKGROUND: Klebsiella pneumoniae liver abscess (KLA) is emerging worldwide due to hypermucoviscous strains with a propensity for metastatic infection. Treatment includes drainage and prolonged intravenous antibiotics. We aimed to determine whether oral antibiotics were noninferior to continued intravenous antibiotics for KLA. METHODS: This noninferiority, parallel group, randomized, clinical trial recruited hospitalized adults with liver abscess and K. pneumoniae isolated from blood or abscess fluid who had received ≤7 days of effective antibiotics at 3 sites in Singapore. Patients were randomized 1:1 to oral (ciprofloxacin) or intravenous (ceftriaxone) antibiotics for 28 days. If day 28 clinical response criteria were not met, further oral antibiotics were prescribed until clinical response was met. The primary endpoint was clinical cure assessed at week 12 and included a composite of absence of fever in the preceding week, C-reactive protein <20 mg/L, and reduction in abscess size. A noninferiority margin of 12% was used. RESULTS: Between November 2013 and October 2017, 152 patients (mean age, 58.7 years; 25.7% women) were recruited, following a median 5 days of effective intravenous antibiotics. A total of 106 (69.7%) underwent abscess drainage; 71/74 (95.9%) randomized to oral antibiotics met the primary endpoint compared with 72/78 (92.3%) randomized to intravenous antibiotics (risk difference, 3.6%; 2-sided 95% confidence interval, -4.9% to 12.8%). Effects were consistent in the per-protocol population. Nonfatal serious adverse events occurred in 12/72 (16.7%) in the oral group and 13/77 (16.9%) in the intravenous group. CONCLUSIONS: Oral antibiotics were noninferior to intravenous antibiotics for the early treatment of KLA. CLINICAL TRIALS REGISTRATION: NCT01723150.

Acquisition of Plasmid with Carbapenem-Resistance Gene blaKPC2 in Hypervirulent Klebsiella pneumoniae, Singapore.

The convergence of carbapenem-resistance and hypervirulence genes in Klebsiella pneumoniae has led to the emergence of highly drug-resistant superbugs capable of causing invasive disease. We analyzed 556 carbapenem-resistant K. pneumoniae isolates from patients in Singapore hospitals during 2010-2015 and discovered 18 isolates from 7 patients also harbored hypervirulence features. All isolates contained a closely related plasmid (pKPC2) harboring blaKPC-2, a K. pneumoniae carbapenemase gene, and had a hypervirulent background of capsular serotypes K1, K2, and K20. In total, 5 of 7 first patient isolates were hypermucoviscous, and 6 were virulent in mice. The pKPC2 was highly transmissible and remarkably stable, maintained in bacteria within a patient with few changes for months in the absence of antimicrobial drug selection pressure. Intrapatient isolates were also able to acquire additional antimicrobial drug resistance genes when inside human bodies. Our results highlight the potential spread of carbapenem-resistant hypervirulent K. pneumoniae in Singapore.

Genomic Study of blaIMI-Positive Enterobacter cloacae Complex in Singapore over a Five-Year Study Period.

The blaIMI gene is rarely detected outside the Enterobacter genus. Genomic characterization of 87 blaIMI-positive Enterobacter cloacae complex members revealed that the largest phylogenomic clade was made up of E. cloacae subsp. cloacae (71.3%), followed by the newly described species E. bugandensis (13.8%), E. sichuanensis (10.3%), and E. roggenkampii (4.6%). IMI-1 was the predominant carbapenemase variant (86/87, 98.9%). All the blaIMI genes were associated with chromosomally integrated Xer-dependent integrative mobile elements (IMEXs), with two new variants detected.

Identification of AbaR4 Acinetobacter baumannii resistance island in clinical isolates of blaOXA-23-positive Proteus mirabilis.

OBJECTIVES: bla OXA-23 is a class D carbapenemase-encoding gene typical of the Acinetobacter genus. However, its occurrence in the Enterobacteriaceae is uncommon. Here we provide the genome characterization of blaOXA-23-positive Proteus mirabilis. METHODS: In Singapore, a national surveillance of carbapenem non-susceptible clinical Enterobacteriaceae has enabled the collection of OXA-23 bearing isolates. Three clinical P. mirabilis were whole-genome sequenced using Oxford Nanopore MinION and Illumina platforms. The sequence accuracy of MinION long-read contigs was enhanced by polishing with Illumina-derived short-read data. RESULTS: In two P. mirabilis genomes, blaOXA-23 was detected as two copies, present on the chromosome and on a 60018 bp plasmid. blaOXA-23 was associated with the classic Acinetobacter composite transposon Tn2006, bounded by two copies of ISAba1 bracketing the carbapenemase gene. The Tn2006 itself was embedded within an Acinetobacter baumannii AbaR4 resistance island. In the chromosome, the AbaR4 was found integrated into the comM gene, which is also the preferred 'hotspot' in A. baumannii. In the plasmid, AbaR4 integrated into a putative colicin gene. CONCLUSIONS: Our description of an A. baumannii AbaR4 encoding blaOXA-23 in P. mirabilis is to our knowledge the first description of an Acinetobacter resistance island in Proteus and suggests that P. mirabilis may be a reservoir for this class D carbapenemase gene.

Complete Genome Sequence of Candida theae from Hickman Line Infection in an Immunocompromised Child.

We present the first whole-genome-sequencing data of a rare fungal species, Candida theae isolated in the context of a Hickman line infection in a patient with juvenile myelomonocytic leukaemia. To our knowledge, this is the first instance of publicly available genomic data for this species. Loci associated with antifungal resistance were referenced against its closely related members of the Candida parapsilosis complex.

Antecedent Carbapenem Exposure as a Risk Factor for Non-Carbapenemase-Producing Carbapenem-Resistant Enterobacteriaceae and Carbapenemase-Producing Enterobacteriaceae.

Carbapenem-resistant Enterobacteriaceae (CRE) can be mechanistically classified into carbapenemase-producing Enterobacteriaceae (CPE) and non-carbapenemase-producing carbapenem nonsusceptible Enterobacteriaceae (NCPCRE). We sought to investigate the effect of antecedent carbapenem exposure as a risk factor for NCPCRE versus CPE. Among all patients with CRE colonization and infection, we conducted a case-control study comparing patients with NCPCRE (cases) and patients with CPE (controls). The presence of carbapenemases was investigated with phenotypic tests followed by PCR for predominant carbapenemase genes. We included 843 unique patients with first-episode CRE, including 387 (45.9%) NCPCRE and 456 (54.1%) CPE. The resistance genes detected in CPEs were blaNDM (42.8%), blaKPC (38.4%), and blaOXA-48-like (12.1%). After adjusting for confounders and clustering at the institutional level, the odds of prior 30-day carbapenem exposure was three times higher among NCPCRE than CPE patients (adjusted odds ratio [aOR], 3.48; 95% confidence interval [CI], 2.39 to 5.09; P < 0.001). The odds of prior carbapenem exposure and NCPCRE detection persisted in stratified analyses by Enterobacteriaceae species (Klebsiella pneumoniae and Escherichia coli) and carbapenemase gene (blaNDM and blaKPC). CPE was associated with male gender (aOR, 1.45; 95% CI, 1.07 to 1.97; P = 0.02), intensive care unit stay (aOR, 1.84; 95% CI, 1.24 to 2.74; P = 0.003), and hospitalization in the preceding 1 year (aOR, 1.42; 95% CI, 1.01 to 2.02; P = 0.05). In a large nationwide study, antecedent carbapenem exposure was a significant risk factor for NCPCRE versus CPE, suggesting a differential effect of antibiotic selection pressure.

Challenge of drug resistance in Pseudomonas aeruginosa: clonal spread of NDM-1-positive ST-308 within a tertiary hospital.

OBJECTIVES: MDR Pseudomonas aeruginosa is a serious global threat to healthcare institutions. The mechanism by which drug resistance can be acquired is variable, but acquired carbapenemase production has been reported in P. aeruginosa. An investigation was performed to determine the rate and genomic epidemiology of New Delhi MBL (NDM) in ß-lactam-non-susceptible isolates. METHODS: P. aeruginosa isolates from a tertiary hospital in Singapore between January 2015 and February 2018 were investigated for the presence of NDM genes. RESULTS: Out of 298 pan-ß-lactam-non-susceptible isolates, 31 were found to be NDM positive (10.4%). WGS demonstrated that all 31 NDM-positive isolates were clonal, belonging to ST-308. blaNDM was chromosomally inserted within an integrative and conjugative element (ICE), ICETn43716385. The NDM-P. aeruginosa isolates possessed an extensive repertoire of both cell-associated [flagella, pili, alginate/biofilm, LPS, type III secretion system (T3SS) and type VI secretion system (T6SS)] and secreted virulence factors. Antibiograms revealed higher rates of drug resistance in NDM-positive isolates compared with their non-NDM counterparts. The NDM isolates remained 100% susceptible only to colistin. CONCLUSIONS: The combination of chromosomal mutations, acquired resistance genes and virulence factors likely facilitated the persistent and ongoing spread of the ST-308 clade of P. aeruginosa within the hospital. Our study illustrates the particular threat of NDM-positive P. aeruginosa in a tertiary hospital setting in the era of antimicrobial resistance.

In vitro activity of apramycin against multidrug-, carbapenem- and aminoglycoside-resistant Enterobacteriaceae and Acinetobacter baumannii.

OBJECTIVES: Widespread antimicrobial resistance often limits the availability of therapeutic options to only a few last-resort drugs that are themselves challenged by emerging resistance and adverse side effects. Apramycin, an aminoglycoside antibiotic, has a unique chemical structure that evades almost all resistance mechanisms including the RNA methyltransferases frequently encountered in carbapenemase-producing clinical isolates. This study evaluates the in vitro activity of apramycin against multidrug-, carbapenem- and aminoglycoside-resistant Enterobacteriaceae and Acinetobacter baumannii, and provides a rationale for its superior antibacterial activity in the presence of aminoglycoside resistance determinants. METHODS: A thorough antibacterial assessment of apramycin with 1232 clinical isolates from Europe, Asia, Africa and South America was performed by standard CLSI broth microdilution testing. WGS and susceptibility testing with an engineered panel of aminoglycoside resistance-conferring determinants were used to provide a mechanistic rationale for the breadth of apramycin activity. RESULTS: MIC distributions and MIC90 values demonstrated broad antibacterial activity of apramycin against Escherichia coli, Klebsiella pneumoniae, Enterobacter spp., Morganella morganii, Citrobacter freundii, Providencia spp., Proteus mirabilis, Serratia marcescens and A. baumannii. Genotypic analysis revealed the variety of aminoglycoside-modifying enzymes and rRNA methyltransferases that rendered a remarkable proportion of clinical isolates resistant to standard-of-care aminoglycosides, but not to apramycin. Screening a panel of engineered strains each with a single well-defined resistance mechanism further demonstrated a lack of cross-resistance to gentamicin, amikacin, tobramycin and plazomicin. CONCLUSIONS: Its superior breadth of activity renders apramycin a promising drug candidate for the treatment of systemic Gram-negative infections that are resistant to treatment with other aminoglycoside antibiotics.

Klebsiella pneumoniae and Klebsiella quasipneumoniae define the population structure of blaKPC-2Klebsiella: a 5 year retrospective genomic study in Singapore.

OBJECTIVES: To describe the population structure, molecular epidemiology and genetic context of blaKPC-2-bearing Klebsiella pneumoniae. METHODS: Isolates (n = 157) were retrospective, phenotypically carbapenem-resistant blaKPC-positive K. pneumoniae, collected from public hospitals. WGS was performed on the Illumina platform. Phylogenomic analysis, screening of resistance and virulence genes, and comparison of the genetic environment of blaKPC were carried out. RESULTS: Based on core-tree phylogeny, 67.5% of the isolates were K. pneumoniae and the remainder comprised Klebsiella quasipneumoniae. No Klebsiella variicola strains were observed. Only a single K. pneumoniae carbapenemase (KPC) variant type, blaKPC-2, was seen. MLSTs were diverse and did not comprise the 'traditional' KPC clonal group (CG) 258. blaKPC-2 was associated with a non-Tn4401 element (NTE) in >99% of genomes. Screening for four key virulence loci: yersiniabactin (ybt), aerobactin (iuc), salmochelin (iro) and colibactin (clb) as well as ICEKp (virulence-associated integrative conjugative element of K. pneumoniae), revealed the lack of virulence factors and ICEKp within K. quasipneumoniae. Amongst the K. pneumoniae, there were 32 ybt+ isolates (32/106, 30.2%) and, of these, 8 isolates were also clb+ (7.5%). K. pneumoniae serotypes K1 and K2, the majority of capsular serotype seen in patients with invasive liver abscess syndrome, were detected at 4.5% (7/157). CONCLUSIONS: Results suggest that dissemination of blaKPC-2 is driven by NTEKPC in non-ST258 isolates. The detection of blaKPC-2K. pneumoniae serotypes K1/K2 carrying virulence factors, albeit in low numbers, reflects the worrisome convergence of carbapenem resistance and hypervirulence in K. pneumoniae.

Putative Integrative Mobile Elements That Exploit the Xer Recombination Machinery Carrying blaIMI-Type Carbapenemase Genes in Enterobacter cloacae Complex Isolates in Singapore.

Whole-genome sequencing was performed on 16 isolates of the carbapenemase-producing Enterobacter cloacae complex to determine the flanking regions of blaIMI-type genes. Phylogenetic analysis of multilocus sequence typing (MLST) targets separated the isolates into 4 clusters. The blaIMI-type genes were all found on Xer-dependent integrative mobile elements (IMEX). The IMEX elements of 5 isolates were similar to those described in Canada, while the remainder were novel. Five isolates had IMEX elements lacking a resolvase and recombinase.

2015 Epidemic of Severe Streptococcus agalactiae Sequence Type 283 Infections in Singapore Associated With the Consumption of Raw Freshwater Fish: A Detailed Analysis of Clinical, Epidemiological, and Bacterial Sequencing Data.

BACKGROUND: Streptococcus agalactiae (group B Streptococcus [GBS]) has not been described as a foodborne pathogen. However, in 2015, a large outbreak of severe invasive sequence type (ST) 283 GBS infections in adults epidemiologically linked to the consumption of raw freshwater fish occurred in Singapore. We attempted to determine the scale of the outbreak, define the clinical spectrum of disease, and link the outbreak to contaminated fish. METHODS: Time-series analysis was performed on microbiology laboratory data. Food handlers and fishmongers were screened for enteric carriage of GBS. A retrospective cohort study was conducted to assess differences in demographic and clinical characteristics of patients with invasive ST283 and non-ST283 infections. Whole-genome sequencing was performed on human and fish ST283 isolates from Singapore, Thailand, and Hong Kong. RESULTS: The outbreak was estimated to have started in late January 2015. Within the study cohort of 408 patients, ST283 accounted for 35.8% of cases. Patients with ST283 infection were younger and had fewer comorbidities but were more likely to develop meningoencephalitis, septic arthritis, and spinal infection. Of 82 food handlers and fishmongers screened, none carried ST283. Culture of 43 fish samples yielded 13 ST283-positive samples. Phylogenomic analysis of 161 ST283 isolates from humans and fish revealed they formed a tight clade distinguished by 93 single-nucleotide polymorphisms. CONCLUSIONS: ST283 is a zoonotic GBS clone associated with farmed freshwater fish, capable of causing severe disease in humans. It caused a large foodborne outbreak in Singapore and poses both a regional and potentially more widespread threat.

Clinical and Molecular Epidemiology of Carbapenem-Resistant Enterobacteriaceae Among Adult Inpatients in Singapore.

BACKGROUND: Since 2010, the incidence of carbapenem-resistant Enterobacteriaceae (CRE) has been increasing in Singapore. We analyzed the clinical and molecular epidemiology of CRE among adult inpatients in Singapore. METHODS: Quarterly incidence of unique subjects (per 100000 patient-days) with positive clinical and surveillance cultures for CRE were estimated based on mandatory data submitted to the National Public Health Laboratory by public hospitals between 2010 and 2015. CRE-positive adult inpatients were prospectively recruited from 6 public sector hospitals between December 2013 and April 2015. Subjects answered a standardized epidemiologic questionnaire and provided samples for this study. Further clinical information was extracted from subjects' electronic medical records. Whole-genome sequencing was performed on study isolates to determine transmission clusters. RESULTS: Incidence of CRE clinical cultures among adult inpatients plateaued from 2013 (range: 7.73 to 10.32 per 100000 patient-days) following an initial increase between 2010 and end-2012. We prospectively recruited 249 subjects. Their median age was 65 years, 108 (43%) were female, and 161 (64.7%) had carbapenemase-producing Enterobacteriaceae (CPE). On multivariate analysis, prior carbapenem exposure (OR: 3.23; 95% CI: 1.67-6.25) and hematological malignancies (OR: 2.85; 95% CI: 1.10-7.41) were associated with non-carbapenemase-producing CRE (NCPE) (n = 88) compared with CPE (n = 161) subjects. Among 430 CRE isolates from the 249 subjects, 307(71.3%) were CPE, of which 154(50.2%) were blaKPC-positive, 97(31.6%) blaNDM-positive, and 42 (13.7%) blaOXA-positive. Klebsiella pneumoniae (n = 180, 41.9%), Escherichia coli (n = 129, 30.0%) and Enterobacter cloacae (n = 62, 14.4%) were the main Enterobacteriaceae species. WGS (n = 206) revealed diverse bacterial strain type (STs). The predominant blaKPC-positive plasmid was pHS102707 (n = 62, 55.4%) and the predominant blaNDM-positive plasmid was pNDM-ECS01 (n = 46, 48.9%). Five transmission clusters involving 13 subjects were detected. CONCLUSIONS: Clinical CRE trend among adult inpatients showed stabilization following a rapid rise since introduction in 2010 potentially due to infection prevention measures and antimicrobial stewardship. More work is needed on understanding CPE transmission dynamics.