Exopolysaccharide is the potential effector of Lactobacillus fermentum PS150, a hypnotic psychobiotic strain.

Psychobiotics are a class of probiotics that confer beneficial effects on the mental health of the host. We have previously reported hypnotic effects of a psychobiotic strain, Lactobacillus fermentum PS150 (PS150), which significantly shortens sleep latency in experimental mice, and effectively ameliorate sleep disturbances caused by either caffeine consumption or a novel environment. In the present study, we discovered a L. fermentum strain, GR1009, isolated from the same source of PS150, and found that GR1009 is phenotypically distinct but genetically similar to PS150. Compared with PS150, GR1009 have no significant hypnotic effects in the pentobarbital-induced sleep test in mice. In addition, we found that heat-killed PS150 exhibited hypnotic effects and altered the gut microbiota in a manner similar to live bacteria, suggesting that a heat-stable effector, such as exopolysaccharide (EPS), could be responsible for these effects. Our comparative genomics analysis also revealed distinct genetic characteristics in EPS biosynthesis between GR1009 and PS150. Furthermore, scanning electron microscopy imaging showed a sheet-like EPS structure in PS150, while GR1009 displayed no apparent EPS structure. Using the phenol-sulfate assay, we found that the sugar content value of the crude extract containing EPS (C-EPS) from PS150 was approximately five times higher than that of GR1009, indicating that GR1009 has a lower EPS production activity than PS150. Through the pentobarbital-induced sleep test, we confirmed the hypnotic effects of the C-EPS isolated from PS150, as evidenced by a significant reduction in sleep latency and recovery time following oral administration in mice. In summary, we utilized a comparative approach to delineate differences between PS150 and GR1009 and proposed that EPS may serve as a key factor that mediates the observed hypnotic effect.

Integrative and Conjugative Element-Mediated Azithromycin Resistance in Multidrug-Resistant Salmonella enterica serovar Albany.

We identified an erm42-carrying integrative and conjugative element, ICE_erm42, in 26.4% of multidrug-resistant Salmonella enterica serovar Albany isolates recovered from human salmonellosis between 2014 and 2019 in Taiwan. ICE_erm42-carrying strains displayed high-level resistance to azithromycin and the element could move into the phylogenetically distant Vibrio cholerae via conjugation.

Novel Paired Cell Lines for the Study of Lipid Metabolism and Cancer Stemness of Hepatocellular Carcinoma.

There are few well-characterized syngeneic murine models for hepatocellular carcinoma (HCC), which limits immunological studies and the development of immunotherapies for HCC. We previously established an oncogene-induced spontaneous HCC mouse model based on transposon-mediated oncogene (AKT and NRASV12) insertion into the genome of hepatocytes to induce tumorigenesis. Two tumor clones with different levels of lipid droplets (LDs) showed similar in vitro growth but distinctive in vivo phenotypes, including divergent proliferative capability and varying induction of myeloid-derived suppressor cells (MDSCs). The two clones showed distinct gene expression related to lipid metabolism, glycolysis, and cancer stemness. Endogenous fatty acid (FA) synthesis and exogenous monounsaturated fatty acid (MUFA) consumption promoted both tumor proliferation and cancer stemness, and upregulated c-Myc in the HCC cell lines. Moreover, the LDhi HCC cell line expressed a higher level of type II IL-4 receptor, which promoted tumor proliferation through binding IL-4 or IL-13. The chromosomal DNA of two tumor clones, NHRI-8-B4 (LDhi) and NHRI-1-E4 (LDlo) showed five identical AKT insertion sites in chromosomes 9, 10, 13, 16 and 18 and two NRAS integration sites in chromosomes 2 and 3. Herein, we describe two novel HCC cell lines with distinct features of lipid metabolism related to cancer stemness and differential interplay with the immune system, and present this syngeneic HCC mouse model as a practical tool for the study of cancer stemness and discovery of new therapies targeting liver cancers.

The Evolutionary Trend and Genomic Features of an Emerging Lineage of Elizabethkingia anophelis Strains in Taiwan.

The incidence of Elizabethkingia anophelis bacteremia increased significantly in a tertiary hospital, Changhua Christian Hospital (CCH) since 2013. The infection density was 1.3 and 8.1 cases per 100,000 patient-days between 2005 and 2012 and 2013 and 2020, respectively (P < 0.05). During an outbreak investigation, a specific lineage of E. anophelis strains was identified by the pulsed-field gel electrophoresis analysis. To evaluate the evolution of the specific E. anophelis lineage, whole-genome sequencing was performed, and unique genomic features (GRs) were determined by comparative genomic analysis. The specific E. anophelis lineage was novel compared to worldwide strains ever reported by cg-MLST phylogenic and whole-genome comparative analysis. Multiplex PCR using primers designed from unique GRs were performed for prevalence screening among isolates from the CCH and nationwide isolates from the Taiwan surveillance of Antimicrobial Resistance (TSAR) Program. The proportion of the specific E. anophelis lineage increased from 7.9% (3/38) during 2005-2012 to 89.2% (223/250) during 2013-2020 (P < 0.05). Although E. anophelis usually confers resistance to multiple antibiotics with limited therapeutic options, the E. anophelis strains in the specific lineage had higher ciprofloxacin resistance (100% [226/226] versus 27.4% [17/62], P < 0.05) and was associated with a higher 14-day mortality rates (33.2% [37/226] versus 16.1% [10/62], P < 0.05) than other strains at CCH. A similarly increasing trend was also found in the national TSAR program during 2002-2018 (p for trend <0.05). We concluded that a novel lineage of E. anophelis strains has emerged dominantly in Taiwan. The genomic features are important for further investigations of epidemiology, resistance, virulence, and appropriate treatment. IMPORTANCE Elizabethkingia anophelis is an emerging multidrug resistant pathogen caused several global outbreaks recently. E. anophelis was frequently misidentified as E. meningoseptica in the past by conventional culture methods; therefore, the prevalence was often underestimated. Through revised identification, an increasing trend of E. anophelis infection was noted in a tertiary hospital and a dominant lineage of strains was recognized by genotyping. To our best knowledge, the dominant lineage of E. anophelis is novel in comparison to other worldwide strains by whole-genome comparative analysis and several unique genomic regions were found. The whole-genome sequencing data also demonstrated multiple putative virulence factors and genes associated with multidrug resistance. In our study, we identified a specially evolved E. anophelis in Taiwan with increasing nationwide dominance. This study will assist in further epidemiology surveillance and developing corresponsive infection control policies to restrain it potential of global dissemination.

RamAp Is an Efflux Pump Regulator Carried by an IncHI2 Plasmid.

In investigating the epidemiological trends of Salmonella enterica serovar Goldcoast, we previously identified several closely related strains with different MICs to azithromycin and quinolones. Genome sequencing and comparison of two very similar multidrug-resistant (MDR) strains, R18.0877 and R18.1656, has led to the identification of an extra plasmid-borne ramA gene, ramAp, on the large IncHI2 plasmid carried by R18.0877. The ramAp gene is located in a 953-bp region on the plasmid, which is identical to that of the Klebsiella quasipneumoniae chromosomal ramA loci. A truncated ISEcp1 located at the adjacent upstream area of the putative regulatory region of ramAp may likely contribute to its mobilization and expression. Introducing the ramAp gene and the truncated ISEcp1 into Escherichia coli has resulted in elevated expression of efflux pump genes and elevated MICs to chloramphenicol, azithromycin, nalidixic acid, ciprofloxacin, sulfamethoxazole, trimethoprim, tetracycline, and tigecycline. The ramAp is an extra efflux pump activator gene that potentially could be transmitted with the IncHI2 plasmid among bacteria. It is plausible that, with high interspecific conservation, the plasmid-encoded regulator reduces drug susceptibility by activating existing efflux pump systems of the host and thus can be regarded as a new type of auxiliary antimicrobial resistance determinant. Sequences of similar plasmids were found worldwide. Its impact on the emergence of antimicrobial resistance among bacterial pathogens is worrisome.

Increasing New Delhi metallo-ß-lactamase-positive Escherichia coli among carbapenem non-susceptible Enterobacteriaceae in Taiwan during 2016 to 2018.

New Delhi metallo-ß-lactamase (NDM) had been reported to be the predominant carbapenemase among Escherichia coli in Taiwan. However, studies focusing on the clonal background and epidemiology of plasmids carrying NDM genes were limited. Between 2016 and 2018, all clinical E. coli and Klebsiella pneumoniae isolates that were non-susceptible to ertapenem, meropenem, and imipenem were tested for carbapenemase-encoding genes (CEGs) and antimicrobial susceptibilities. Molecular typing was performed on all carbapenemase-producing isolates. Whole genome sequencing (WGS) was performed on all NDM-positive E. coli isolates. Twenty-three (29.5%) of 78 carbapenem non-susceptible E. coli and 108 (35.3%) of 306 carbapenem non-susceptible K. pneumoniae isolates carried CEGs. The most prevalent CEGs in carbapenemase-producing E. coli (CPEc) were blaNDM (39.1%) and blaIMP-8 (30.4%), while that in carbapenemase-producing K. pneumoniae was Klebsiella pneumoniae carbapenemase (KPC) (72.2%). Fifteen sequence types were identified among 23 CPEc, and 55.6% of NDM-positive E. coli isolates belonged to ST410. WGS showed ST410 isolates were highly clonal and similar to those from other countries. All NDM-5-positive E. coli isolates carried identical IncX3 plasmid harboring blaNDM-5 but no other antimicrobial resistance (AMR) genes. In each of the four NDM-1-positive E. coli isolates, the blaNDM-1 was present in a ∼ 300 kb IncHI2/IncHI2A plasmid which carried an array of AMR genes. NDMs are the most prevalent carbapenemase among CPEc in Taiwan. Awareness should be raised as the prevalence of NDM-positive E. coli might increase rapidly with IncX3 plasmid and globally distributed strain ST410 being the potential vectors for wide dissemination.

Transmission and evolution of OXA-48-producing Klebsiella pneumoniae ST11 in a single hospital in Taiwan.

OBJECTIVES: Epidemic spread of OXA-48-producing Klebsiella pneumoniae, mainly mediated by the transmission of a blaOXA-48-carrying plasmid, has threatened global health during the last decade. Since its introduction to Taiwan in 2013, OXA-48 has become the second most common carbapenemase. We described the transmission and evolution of an OXA-producing K. pneumoniae clone in a single hospital. METHODS: Twenty-two OXA-48 K. pneumoniae were isolated between October 2013 and December 2015. Comparative genomic analysis was performed based on the WGS data generated with Illumina and MinION techniques. RESULTS: Seventeen of the 22 OXA-48 K. pneumoniae that belonged to ST11, with the same capsular genotype, KL64, and differed from each other by seven or fewer SNPs, were considered outbreak strains. Eight of the 17 outbreak strains harboured a 65499 bp blaOXA-48-carrying IncL plasmid (called pOXA48). pOXA48 was absent from the remaining nine strains. Instead, a 24.9 kb blaOXA-48-carrying plasmid fragment was integrated into a prophage region of their chromosomes. Transmission routes of the ST11_KL64 K. pneumoniae sublineages, which carried either pOXA48 or chromosomally integrated blaOXA-48, were reconstructed. CONCLUSIONS: Clonal expansion of ST11_KL64 sublineages contributed to the nosocomial outbreak of OXA-48 K. pneumoniae. The chromosome-borne blaOXA-48 lineage emerged during a 2 year period in a single hospital. Dissemination of OXA-48, which is vertically transmitted in K. pneumoniae even in the absence of selective pressure from antimicrobials, deserves public health attention.

Complete Genome Sequencing of Elizabethkingia sp. Strain 2-6.

Elizabethkingia sp. strain 2-6 was collected from a water faucet in the intensive care unit of a medical center in Taiwan. The complete genome sequence and annotation are reported. Analysis of the genetic relatedness to the known Elizabethkingia genomes indicated that strain 2-6 may be a new genomospecies of Elizabethkingia.

Lineage-specific SNPs for genotyping of Mycobacterium tuberculosis clinical isolates.

Tuberculosis (TB) is a severe infectious disease worldwide. Genetic variation of the causative agent, Mycobacterium tuberculosis (MTB), determines the outcomes of infection and anti-TB treatment. Until recently, there has been no effective and convenient way for classifying clinical isolates based on the DNA sequences of the divergent lineages of MTB infecting human populations. Here, we identified single nucleotide polymorphisms (SNPs) of six representative strains from Taiwan by whole-genome sequencing and comparing the results to the sequence of the H37Rv reference strain. One hundred and ten SNPs, each unique to one of the six strains, were used to genotype 150 additional isolates by applying DNA mass spectrometry. Lineage-specific SNPs were identified that could distinguish the major lineages of the clinical isolates. A subset including 32 SNPs was found to be sufficient to type four major groups of MTB isolates in Taiwan (ancient Beijing, modern Beijing, East African-Indian, and Latin-American Mediterranean). However, there was high genetic homozygosity within the Euro-American lineage, which included spoligotype-classified Haarlem and T strains. By whole-genome sequencing of 12 representative Euro-American isolates, we identified multiple subtype-specific SNPs which allowed us to distinguish two major branches within the Euro-American lineage.

Colibactin Contributes to the Hypervirulence of pks+ K1 CC23 Klebsiella pneumoniae in Mouse Meningitis Infections.

Klebsiella pneumoniae is the most common pathogen of community-acquired meningitis in Taiwan. However, the lack of a physiologically relevant meningitis model for K. pneumoniae has impeded research into its pathogenesis mechanism. Based on the core genome MLST analyses, the hypervirulent K1 K. pneumoniae strains, which are etiologically implicated in adult meningitis, mostly belong to a single clonal complex, CC23. Some K1 CC23 K. pneumoniae strains carry a gene cluster responsible for colibactin production. Colibactin is a small genotoxic molecule biosynthesized by an NRPS-PKS complex, which is encoded by genes located on the pks island. Compared to other hypervirulent K. pneumoniae which primarily infect the liver, the colibactin-producing (pks+) K1 CC23 strains had significant tropism toward the brain of BALB/c mice. We aimed in this study to develop a physiologically relevant meningitis model with the use of pks+ K1 CC23 K. pneumoniae. Acute meningitis was successfully induced in adult BALB/c male mice through orogastric, intranasal, and intravenous inoculation of pks+ K1 CC23 K. pneumoniae. Besides the typical symptoms of bacterial meningitis, severe DNA damages, and caspase 3-independent cell death were elicited by the colibactin-producing K1 CC23 K. pneumoniae strain. The deletion of clbA, which abolished the production of colibactin, substantially hindered K. pneumoniae hypervirulence in the key pathogenic steps toward the development of meningitis. Our findings collectively demonstrated that colibactin was necessary but not sufficient for the meningeal tropism of pks+ K1 CC23 K. pneumoniae, and the mouse model established in this study can be applied to identify other virulence factors participating in the development of this life-threatening disease.

Dissemination of mcr-1-Carrying Plasmids among Colistin-Resistant Salmonella Strains from Humans and Food-Producing Animals in Taiwan.

We detected the colistin resistance gene mcr-1 in four Salmonella serovars isolated from humans and animals with diarrhea. The resistance gene was carried on different plasmids. One mcr-1-carrying conjugative plasmid, a variant of pHNSHP45, was disseminated among Salmonella isolates recovered from humans, pigs, and chickens.

Prevalence and characteristics of pks genotoxin gene cluster-positive clinical Klebsiella pneumoniae isolates in Taiwan.

The pks gene cluster encodes enzymes responsible for the synthesis of colibactin, a genotoxin that has been shown to induce DNA damage and contribute to increased virulence. The present study investigated the prevalence of pks in clinical K. pneumoniae isolates from a national surveillance program in Taiwan, and identified microbiological and molecular factors associated with pks-carriage. The pks gene cluster was detected in 67 (16.7%) of 400 isolates from various specimen types. Multivariate analysis revealed that isolates of K1, K2, K20, and K62 capsular types (p < 0.001), and those more susceptible to antimicrobial agents (p = 0.001) were independent factors strongly associated with pks-carriage. Phylogenetic studies on the sequence type (ST) and pulsed-field gel electrophoresis patterns indicated that the pks-positive isolates belong to a clonal group of ST23 in K1, a locally expanding ST65 clone in K2, a ST268-related K20 group, and a highly clonal ST36:K62 group. Carriage of rmpA, iutC, and ybtA, the genes associated with hypervirulence, was significantly higher in the pks-positive isolates than the pks-negative isolates (95.5% vs. 13.2%, p < 0.001). Further studies to determine the presence of hypervirulent pks-bearing bacterial populations in the flora of community residents and their association with different disease entities may be warranted.

Genomics Study of Mycobacterium tuberculosis Strains from Different Ethnic Populations in Taiwan.

To better understand the transmission and evolution of Mycobacterium tuberculosis (MTB) in Taiwan, six different MTB isolates (representatives of the Beijing ancient sublineage, Beijing modern sublineage, Haarlem, East-African Indian, T1, and Latin-American Mediterranean (LAM)) were characterized and their genomes were sequenced. Discriminating among large sequence polymorphisms (LSPs) that occur once versus those that occur repeatedly in a genomic region may help to elucidate the biological roles of LSPs and to identify the useful phylogenetic relationships. In contrast to our previous LSP-based phylogeny, the sequencing data allowed us to determine actual genetic distances and to define precisely the phylogenetic relationships between the main lineages of the MTB complex. Comparative genomics analyses revealed more nonsynonymous substitutions than synonymous changes in the coding sequences. Furthermore, MTB isolate M7, a LAM-3 clinical strain isolated from a patient of Taiwanese aboriginal origin, is closely related to F11 (LAM), an epidemic tuberculosis strain isolated in the Western Cape of South Africa. The PE/PPE protein family showed a higher dn/ds ratio compared to that for all protein-coding genes. Finally, we found Haarlem-3 and LAM-3 isolates to be circulating in the aboriginal community in Taiwan, suggesting that they may have originated with post-Columbus Europeans. Taken together, our results revealed an interesting association with historical migrations of different ethnic populations, thus providing a good model to explore the global evolution and spread of MTB.

A Common Flanking Region in Promiscuous Plasmids Encoding blaNDM-1 in Klebsiella pneumoniae Isolated in Singapore.

Bacteria encoding the New Delhi metallo-ß-lactamase gene (blaNDM-1) are regarded as superbugs for their resistance to multiple antibiotics. Plasmids encoding blaNDM-1 have been observed to be spreading among gram-negative bacteria around the world. Previous studies have demonstrated that multiple modifications of blaNDM-1-harboring plasmids might contribute to the spread of the gene. In this study, we analyzed blaNDM-1-encoding plasmids from two Klebsiella pneumoniae isolates, DU7433 and DU1301, found to be unrelated by pulsed field gel electrophoresis and multilocus sequencing typing (DU7433: ST14 and DU1301: ST11), and compared them with previously published plasmids. Although strains DU1301, DU7433, and previously published strain DU43320 carried unrelated plasmids, their transconjugants exhibited similar antimicrobial resistance profiles. Transconjugants lacked the resistance to aztreonam, ciprofloxacin, gentamicin, tetracycline, and trimethoprim/sulfamethoxazole when compared with the corresponding clinical isolates. Plasmids pTR1 from DU1301 and pTR2 from DU7433 had completely different plasmid backbones except a short conserved region of blaNDM-1 and ble flanked with truncated or nontruncated ISAba125 and trpF. The presence of this common region among known blaNDM-1-carrying plasmids implies that the dissemination of blaNDM-1 may be facilitated by mobilization of this conserved immediate region among different plasmids. Control measures should be strictly enforced whenever increasing incidences of epidemiological unrelated strains were identified.

Effective transfer of a 47 kb NDM-1-positive plasmid among Acinetobacter species.

OBJECTIVES: To investigate the link between two NDM-1-positive Acinetobacter isolates from the same hospital, the plasmid profiles of the isolates were examined. These two isolates were found from a surveillance programme within 3 months from two patients without obvious physical contact or hospitalization time overlap. METHODS: Antimicrobial susceptibility tests, genome sequencing of both isolates and plasmid transfer experiments were performed. A comparative study of similar plasmids was performed using BLAST analysis. RESULTS: The antimicrobial susceptibility of the isolates (Acinetobacter soli M131 and Acinetobacter pittii MS32) and their Escherichia coli transconjugants revealed a conjugative plasmid that carried the carbapenem resistance determinant. Eleven plasmids were observed in M131 and three in MS32. Each isolate shared an identical plasmid that carried the blaNDM-1 gene. This 47 271 bp plasmid harbours a conserved blaNDM-1-containing region that is flanked by ISAba125 and ISAba11 elements, and also contains a Ti-type conjugative operon. The plasmid is nearly identical in sequence to those of Acinetobacter isolates from China. In contrast to the mobilization of the blaNDM-1 sequence in Enterobacteriaceae, which is mainly by transposition, this plasmid moves as a whole among Acinetobacter species. Consistently, this plasmid was found to transfer effectively by in vitro conjugation to several Acinetobacter species. CONCLUSIONS: The clinical and laboratory findings suggest that Acinetobacter species may serve as a reservoir of this blaNDM-1 plasmid. Our study demonstrates the potential of applying genome sequencing to the surveillance of antimicrobial-resistant bacteria.

Early radiographic response to epidermal growth factor receptor-tyrosine kinase inhibitor in non-small cell lung cancer patients with epidermal growth factor receptor mutations: A prospective study.

BACKGROUND: The time schedules for response evaluation of epidermal growth factor receptor-tyrosine kinase Inhibitor (EGFR-TKI) in non-small cell lung cancer (NSCLC) patients are still ill-defined. METHODS: Stage IIIB/IV patients with histologically proven NSCLC were enrolled in this study if the tumor cells bore EGFR mutations other than T790M. Eligible patients were treated with either 250 mg of gefitinib or 150 mg of erlotinib once daily. The early response rate [computed tomography (CT) scan on Day 14], definitive response rate determined on Day 56, progression-free survival (PFS), overall survival (OS), and toxicity profile were assessed prospectively. RESULTS: Thirty-nine patients were enrolled in this study. A total of 29 patients (29/39, 74.4%) achieved partial response (PR). Twenty-one patients (21/39, 53.8%) had early radiological response on Day 14. The early radiological response rate in patients with PR was 72.4% (21/29). Only eight patients without a PR on early CT still ended with PR. Among the 29 patients with PR, the PFS (8.1 months) and OS (18.3 months) of the 21 patients with early CT response were shorter than those of the 8 patients without early CT response (11.9 and 24.0 months for PFS and OS, respectively). But the survival differences were statistically non-significant. CONCLUSIONS: A very high percentage (72.4%, 21/29) of NSCLC patients with EGFR mutations with PR demonstrates early radiological response to EGFR-TKIs, which would advocate early radiological examination for EGFR-TKI therapy in NSCLC patients.

Identification of the first imported KPC-3 Klebsiella pneumoniae from the USA to Taiwan.

Establishment of KPC-associated genes into a new region usually requires travellers with hospital admission and their carriage into the communities. In this report, a worldwide spreading clone carrying KPC-3 was isolated from the sputum of a hospitalised patient with a serious infection who had just come from the USA and had been admitted to a New York hospital. By genetic comparison with a strain isolated from New Jersey (NJ-KPC-21), this isolate from the traveller was genetically related. The blaKPC-3 gene was harboured on a large plasmid with a complex structure of a Tn3-based transposon, Tn4401a. The KPC-3-carrying plasmid was very similar (>99.9% identity) to the 113 637-bp blaKPC-3-encoding plasmid pKpQIL that originated from the 2006 epidemic carbapenem-resistant Klebsiella pneumoniae outbreak in Israel. With the first recognition of KPC-2 in 2011 and continuing spread, physicians should be aware of the coming of KPC-3 K. pneumoniae in Taiwan.

Closely related NDM-1-encoding plasmids from Escherichia coli and Klebsiella pneumoniae in Taiwan.

OBJECTIVE: Two plasmids carrying blaNDM-1 isolated from carbapenem-resistant Klebsiella pneumoniae (CR-KP) and carbapenem-resistant Escherichia coli (CR-EC) were sequenced. CR-KP and CR-EC were isolated from two Taiwanese patients without travel histories. METHODS: Complete sequencing of the plasmids (pLK75 and pLK78) was conducted using a shotgun approach. Annotation of the contigs was performed using the RAST Server, followed by manual inspection and correction. RESULTS: These similar plasmids were obtained from two patients with overlapping stays at the same hospital. The pLK75 and pLK78 plasmids were 56,489-bp and 56,072-bp in length, respectively. Plasmid annotation revealed a common backbone similar to the IncN plasmid pR46. The regions flanking the blaNDM-1 genes in these plasmids were very similar to plasmid pNDM-HU01 in Japan, which contains a complex class 1 integron located next to an ISCR1 element. The ISCR1 element has been suggested to provide a powerful mechanism for mobilising antibiotic resistance genes. CONCLUSION: Two indigenous NDM-1-producing Enterobacteriaceae cases were identified for the first time in Taiwan, highlighting the alarming introduction of NDM-1-producing Enterobacteriaceae in this region.