# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 830 | 0 | 0.9769 | Detection and characterisation of 16S rRNA methyltransferase-producing Pseudomonas aeruginosa from the UK and Republic of Ireland from 2003-2015. 16S rRNA methyltransferase (16S RMTase) genes confer high-level aminoglycoside resistance, reducing treatment options for multidrug-resistant Gram-negative bacteria. Pseudomonas aeruginosa isolates (n = 221) exhibiting high-level pan-aminoglycoside resistance (amikacin, gentamicin and tobramycin MICs ≥64, ≥32 and ≥32 mg/L, respectively) were screened for 16S RMTase genes to determine their occurrence among isolates submitted to a national reference laboratory from December 2003 to December 2015. 16S RMTase genes were identified using two multiplex PCRs, and whole-genome sequencing (WGS) was used to identify other antibiotic resistance genes, sequence types (STs) and the genetic environment of 16S RMTase genes. 16S RMTase genes were found in 8.6% (19/221) of isolates, with rmtB4 (47.4%; 9/19) being most common, followed by rmtD3 (21.1%; 4/19), rmtF2 (15.8%; 3/19) and single isolates harbouring rmtB1, rmtC and rmtD1. Carbapenemase genes were found in 89.5% (17/19) of 16S RMTase-positive isolates, with bla(VIM) (52.9%; 9/17) being most common. 16S RMTase genes were found in 'high-risk' clones known to harbour carbapenemase genes (ST233, ST277, ST357, ST654 and ST773). Analysis of the genetic environment of 16S RMTase genes identified that IS6100 was genetically linked to rmtB1; IS91 to rmtB4, rmtC or rmtD3; ISCR14 to rmtD1; and rmtF2 was linked to Tn3, IS91 or Tn1721. Although 16S RMTase genes explained only 8.6% of pan-aminoglycoside resistance in the P. aeruginosa isolates studied, the association of 16S RMTase genes with carbapenemase-producers and 'high-risk' clones highlights that continued surveillance is required to monitor spread as well as the importance of suppressing the emergence of dually-resistant clones in hospital settings. | 2022 | 35176475 |
| 1740 | 1 | 0.9768 | MDR Escherichia coli carrying CTX-M-24 (IncF[F-:A1:B32]) and KPC-2 (IncX3/IncU) plasmids isolated from community-acquired urinary trainfection in Brazil. Acquired antibiotic resistance in bacteria has become an important worldwide challenge. Currently, several bacteria, including Escherichia coli, have multidrug resistance profiles. Genes such as bla CTX-M-24 and bla KPC-2 (carbapenemase) are widespread. This research letter reports about a genomic surveillance study where multidrug-resistant E. coli containing CTX-M-24(IncF [F-:A1:B32]) and KPC-2(IncX3/IncU) plasmids were obtained from community- acquired urinary tract infection in Brazil. | 2022 | 36228665 |
| 1390 | 2 | 0.9766 | Oxacillinase-484-Producing Enterobacterales, France, 2018-2023. We examined the emergence and characteristics of oxacillinase-484-producing Enterobacterales in France during 2012-2023. Genomic analysis identified 2 predominant sequence types in Escherichia coli: ST410 and ST1722. Plasmid analysis revealed that bla(OXA-484) genes were carried mostly on an IncX3-type plasmid associated with genetic elements including insertion sequences IS3000 and ISKpn19. | 2024 | 39320334 |
| 1391 | 3 | 0.9766 | Faecal carriage of extended-spectrum β-lactamase-producing and AmpC β-lactamase-producing bacteria among Danish army recruits. During May and June 2008, 84 Danish army recruits were tested for faecal carriage of extended-spectrum β-lactamase (ESBL)-producing and AmpC β-lactamase-producing bacteria. Three ESBL-producing (CTX-M-14a) Escherichia coli isolates, two AmpC-producing (CMY-2) E. coli isolates and one AmpC-producing (CMY-34) Citrobacter freundii isolate were detected. Two of the CTX-M-14a E. coli isolates had similar pulsed-field gel electrophoresis and multilocus sequence typing profiles, indicating the same origin or transmission between the two army recruits. The bla(CTX-M-14a) genes were transferable to an E. coli recipient. These commensal bacteria therefore constitute a reservoir of resistance genes that can be transferred to other pathogenic bacteria in the intestine. | 2011 | 20718802 |
| 1990 | 4 | 0.9764 | Genomic Analysis of Aeromonas veronii C198, a Novel Mcr-3.41-Harboring Isolate from a Patient with Septicemia in Thailand. The resistance of Gram-negative bacteria to colistin, mediated by plasmid-borne mcr genes, is an emerging public health concern. The complete genome sequence (4.55 Mb) of a clinical isolate of Aeromonas veronii biovar veronii obtained from a patient with septicemia was determined using short-read and long-read platforms. This isolate (C198) was found to harbor a novel mcr-3 gene, designated mcr-3.41. Isolate C198 revealed adjacent mcr-3.41 and mcr-3-like genes. It contained one chromosome and two plasmids, both of which encoded a RepB replication protein. Other antimicrobial resistance genes, including bla(cphA3), bla(OXA-12), tetA, rsmA, and adeF, were also present. Isolate C198 was resistant to amoxicillin-clavulanate, ampicillin-sulbactam and tetracycline, and showed intermediate resistance to trimethoprim-sulfamethoxazole. The isolate was susceptible to piperacillin-tazobactam, carbapenem, third-generation cephalosporins, fluoroquinolones, chloramphenicol, and aminoglycosides. Putative virulence genes in the C198 genome encoded type II, III, and VI secretion systems; type IV Aeromonas pili; and type I fimbria, flagella, hemagglutinin, aerolysin, and hemolysins. Multilocus sequence typing revealed a novel sequence type (ST), ST720 for C198. Phylogenetic analysis of the single nucleotide polymorphisms in C198 demonstrated that the strain was closely related to A. veronii 17ISAe. The present study provides insights into the genomic characteristics of human A. veronii isolates. | 2020 | 33317051 |
| 1408 | 5 | 0.9764 | Six Extensively Drug-Resistant Bacteria in an Injured Soldier, Ukraine. Blood and surveillance cultures from an injured service member from Ukraine grew Acinetobacter baumannii, Klebsiella pneumoniae, Enterococcus faecium, and 3 distinct Pseudomonas aeruginosa strains. Isolates were nonsusceptible to most antibiotics and carried an array of antibiotic resistant genes, including carbapenemases (bla(IMP-1), bla(NDM-1), bla(OXA-23), bla(OXA-48), bla(OXA-72)) and 16S methyltransferases (armA and rmtB4). | 2023 | 37406356 |
| 1401 | 6 | 0.9761 | Molecular Surveillance of Multidrug-Resistant Bacteria among Refugees from Afghanistan in 2 US Military Hospitals during Operation Allies Refuge, 2021. In 2021, two US military hospitals, Landstuhl Regional Medical Center in Landstuhl, Germany, and Walter Reed National Military Medical Center (WRNMMC) in Bethesda, Maryland, USA, observed a high prevalence of multidrug-resistant bacteria among refugees evacuated from Afghanistan during Operation Allies Refuge. Multidrug-resistant isolates collected from 80 patients carried an array of antimicrobial resistance genes, including carbapenemases (bla(NDM-1), bla(NDM-5), and bla(OXA-23)) and 16S methyltransferases (rmtC and rmtF). Considering the rising transmission of antimicrobial resistance and unprecedented population displacement globally, these data are a reminder of the need for robust infection control measures and surveillance. | 2024 | 39530854 |
| 837 | 7 | 0.9760 | Diversity of Carbapenem Resistance Mechanisms in Clinical Gram-Negative Bacteria in Pakistan. Antibiotic resistance is a health challenge worldwide. Carbapenem resistance in Gram-negative bacteria is a major problem since treatment options are very limited. Tigecycline and colistin are drugs of choice in this case, but resistance to these drugs is also high. The aim of this study was to describe the diversity of resistance mechanisms in carbapenem-resistant clinical Gram-negative bacteria from Pakistan. Carbapenem-hydrolyzing enzyme-encoding genes were detected using PCR and DNA sequencing and clonal types determined by multilocus sequence typing (MLST). Forty-four carbapenem-resistant isolates were collected from the microbiology laboratory of Fauji Foundation Hospital and Al-Syed Hospital, Rawalpindi, Pakistan, including Klebsiella spp., Escherichia coli, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter cloacae, and Achromobacter xylosoxidans. bla(NDM-1), bla(NDM-4,) bla(NDM-5,) bla(NDM-7), bla(OXA-48), and bla(OXA-181) were detected in Enterobacteriaceae; bla(OXA-23,) bla(OXA-72), and bla(NDM-1) in A. baumannii, and bla(VIM-6) and bla(VIM-11) in P. aeruginosa. MLST analysis revealed several predominant clonal types: ST167 in E. coli, ST147 in Klebsiella pneumoniae, ST2 in Acinetobacter, and ST664 in P. aeruginosa. In Acinetobacter, a new clonal type was observed for the first time. To the best of our knowledge, this is the first study describing the clonality and resistance mechanisms of carbapenem-resistant Gram-negative bacteria in Pakistan. | 2021 | 33211640 |
| 1530 | 8 | 0.9759 | OXA-204 Carbapenemase in Clinical Isolate of Pseudomonas guariconensis, Tunisia. We report an OXA-204-producing Pseudomonas guariconensis clinical isolate in Tunisia, proving the spread of OXA-48 variants beyond Enterobacterales. The bla(OXA-204) gene was carried on a 119-kb chromosomally integrated plasmid fragment, along with multiple additional resistance genes. Surveillance, diagnostic tools, and antimicrobial drug access are needed to mitigate spread of carbapenem-resistant pathogens. | 2025 | 40439456 |
| 952 | 9 | 0.9759 | Molecular Surveillance of ESBL and Carbapenemase Genes in Gram-Negative Bacterial Pathogens Isolated from Various Clinical Samples Collected from Northern Region of United Arab Emirates. The aim of this study was to explore the prevalence of ESBL and carbapenemase genes in Gram-negative bacteria isolated from various clinical samples collected from northern regions of UAE. In total 3670 clinical samples were obtained from patients attending various hospitals and clinics in the northern regions of the UAE. All the samples underwent routine bacterial culture examination, and their antibiotic sensitivity patterns mainly on beta-lactam and carbapenem resistance in Gram-negative bacteria. Molecular detection of ESBL and carbapenemase genes (bla(CTX-M), bla(TEM), bla(SHV), bla(NDM), bla(IMP), and bla(OXA-48)) was performed on them. A total of 249 MDR Gram-negative bacteria (E. coli, K. pneumoniae, P. aeruginosa, P. mirabilis and A. baumannii) were isolated. The genes bla(CTX-M), bla(TEM), and bla(SHV) were detected in all the MDR isolates. Among them, the bla(CTX-M) was predominant especially in E. coli. The bla(NDM) and bla(IMP) were detected in a few K. pneumoniae and A. baumannii. The genes combination bla(CTX-M+TEM) and bla(CTX-M+SHV), bla(CTX-M+SHV), bla(TEM+SHV), and bla(TEM+NDM) were detected mostly in K. pneumoniae and E. coli, and few A. baumannii. The gene combination bla(CTX-M+TEM+SHV) and bla(CTX-M+TEM+SHV+IMP) were also detected in few E. coli, P. aeruginosa, and A. baumannii. The current findings highlight the importance of molecular detection of ESBL and carbapenemase genes to emphasize monitoring and controlling the development of MDR bacterial pathogens. | 2025 | 40871384 |
| 1389 | 10 | 0.9759 | Whole-Genome Sequencing of Gram-Negative Bacteria Isolated From Bovine Mastitis and Raw Milk: The First Emergence of Colistin mcr-10 and Fosfomycin fosA5 Resistance Genes in Klebsiella pneumoniae in Middle East. Antimicrobial resistance is a major concern in the dairy industry. This study investigated the prevalence, antimicrobial resistance phenotypes, and genome sequencing of Gram-negative bacteria isolated from clinical (n = 350) and subclinical (n = 95) bovine mastitis, and raw unpasteurized milk (n = 125). Klebsiella pneumoniae, Aeromonas hydrophila, Enterobacter cloacae (100% each), Escherichia coli (87.78%), and Proteus mirabilis (69.7%) were the most prevalent multidrug-resistant (MDR) species. Extensive drug-resistance (XDR) phenotype was found in P. mirabilis (30.30%) and E. coli (3.33%) isolates. Ten isolates (four E. coli, three Klebsiella species and three P. mirabilis) that displayed the highest multiple antibiotic resistance (MAR) indices (0.54-0.83), were exposed to whole-genome sequencing (WGS). Two multilocus sequence types (MLST): ST2165 and ST7624 were identified among the sequenced E. coli isolates. Three E. coli isolates (two from clinical mastitis and one from raw milk) belonging to ST2165 showed similar profile of plasmid replicon types: IncFIA, IncFIB, IncFII, and IncQ1 with an exception to an isolate that contained IncR, whereas E. coli ST7624 showed a different plasmid profile including IncHI2, IncHI2A, IncI1α, and IncFII replicon types. ResFinder findings revealed the presence of plasmid-mediated colistin mcr-10 and fosfomycin fosA5 resistance genes in a K. pneumoniae (K1) isolate from bovine milk. Sequence analysis of the reconstructed mcr-10 plasmid from WGS of K1 isolate, showed that mcr-10 gene was bracketed by xerC and insertion sequence IS26 on an IncFIB plasmid. Phylogenetic analysis revealed that K1 isolate existed in a clade including mcr-10-harboring isolates from human and environment with different STs and countries [United Kingdom (ST788), Australia (ST323), Malawi (ST2144), Myanmar (ST705), and Laos (ST2355)]. This study reports the first emergence of K. pneumoniae co-harboring mcr-10 and fosA5 genes from bovine milk in the Middle East, which constitutes a public health threat and heralds the penetration of the last-resort antibiotics. Hence, prudent use of antibiotics in both humans and animals and antimicrobial surveillance plans are urgently required. | 2021 | 34956131 |
| 1399 | 11 | 0.9758 | Nationwide Stepwise Emergence and Evolution of Multidrug-Resistant Campylobacter jejuni Sequence Type 5136, United Kingdom. We examined whole-genome-sequenced Campylobacter jejuni and C. coli from 2012-2015 isolated from birds and human stool samples in North East Scotland for the presence of antimicrobial resistance genes. We found that sequence type (ST) 5136 (clonal complex 464) was the most prevalent multidrug-resistant strain of C. jejuni exclusively associated with poultry host reservoirs and recovered from human cases of campylobacteriosis. Tetracycline resistance in ST5136 isolates was due to a tet(O/32/O) mosaic gene, ampicillin resistance was conferred by G → T transversion in the -10 promoter region of bla(OXA-193), fluoroquinolone resistance was due to C257T change in gyrA, and aminoglycoside resistance was conferred by aac. Whole-genome analysis showed that the strain ST5136 evolved from ST464. The nationwide emergence of ST5136 was probably due to stepwise acquisition of antimicrobial resistance genes selected by high use of β-lactam, tetracycline, fluoroquinolone, and aminoglycoside classes of drugs in the poultry industry. | 2019 | 31211671 |
| 1524 | 12 | 0.9757 | Characterization of a Novel mcr-8.2-Bearing Plasmid in ST395 Klebsiella pneumoniae of Chicken Origin. The emergence of mobile colistin resistance mcr genes undermines the efficacy of colistin as the last-resort drug for multi-drug resistance infections and constitutes a great public health concern. Plasmids play a critical role in the transmission of mcr genes among bacteria. One colistin-resistant Klebsiella pneumoniae strain of chicken origin was collected and analyzed by antimicrobial susceptibility testing, PCR, conjugation assay and S1-PFGE. Whole-genome sequencing (WGS) approach combining Illumina and MinION platforms was utilized to decipher the underlying colistin resistance mechanism and genetic context. A novel mcr-8.2-bearing plasmid p2019036D-mcr8-345kb with 345 655 bp in size encoding various resistance genes including floR, sul1, aadA16, aadA2, bla (CTX-M-27), bla (DHA-1), tet(D), dfrA12 and qnrB4 was identified responsible for the colistin resistance phenotype. Plasmid comparison has shown that the mcr-8.2-bearing plasmid differed from other reported plasmids positive for mcr-8.2 but shared the same core mcr-8.2-bearing conserved region. This study demonstrates the emergence of mcr-8.2-bearing K. pneumoniae of animal origin is a potential risk to humans. | 2020 | 32606828 |
| 1240 | 13 | 0.9757 | Prevalence and characterization of quinolone resistance and integrons in clinical Gram-negative isolates from Gaza strip, Palestine. BACKGROUND: Gram-negative bacteria with quinolone resistance and extended-spectrum beta-lactamases (ESBLs) present significant treatment challenges. This study evaluated the prevalence and characteristics of quinolone resistance in Gram-negative strains, investigating the relationship between plasmid-mediated quinolone resistance (PMQR), ESBLs, and integrons. METHODS AND RESULTS: We collected 146 Gram-negative isolates from patients in three Palestinian hospitals. For quinolone resistance isolates, the presence and characterization of PMQR, β-lactamase genes and integrons were studied by PCR and sequencing. Out of 146 clinical isolates, 64 (43.8%) were resistant to quinolones, with 62 (97%) being multidrug-resistant (MDR) and 33 (51.5%) ESBL-producers. PMQR-encoding genes were present in 45 (70.3%) isolates, including aac(6')-Ib-cr (26.6%), qnrA (18.8%), qnrS1 (20.8%), and qnrB (6.4%). Bla(CTX-M) genes were detected in 50% (32/64) of isolates, with bla(CTX-M-15) being the most common. Bla(TEM-1), bla(SHV-1) and bla(VIM) genes were found in 13, 6, and 4 isolates, respectively. Class I integrons were found in 31/64 (48%) of isolates, with 14 containing gene cassettes conferring resistance to trimethoprim (dhfr17, dfrA12, dfrA1) and aminoglycosides resistance genes (aadA1, aadA2, aadA5, and aadA6). CONCLUSIONS: This study found a high rate of quinolone resistance, ESBL and integrons in clinical Gram-negative isolates from our hospitals. Urgent measures are crucial, including implementing an antimicrobial resistance surveillance system, to control and continuously monitor the development of antimicrobial resistance. | 2024 | 39066817 |
| 1235 | 14 | 0.9757 | Characterization of integrons and antimicrobial resistance genes in clinical isolates of Gram-negative bacteria from Palestinian hospitals. Sixty Gram-negative bacterial isolates were collected from Palestinian hospitals in 2006. Thirty-two (53.3%) isolates showed multidrug resistance phenotypes. PCR and DNA sequencing were used to characterize integrons and antimicrobial resistance genes. PCR screening showed that 19 (31.7%) and five (8.3%) isolates were positive for class 1 and class 2 integrons, respectively. DNA-sequencing results for the captured antimicrobial resistance gene cassettes within class 1 integrons identified the following genes: dihydrofolate reductases, dfrA1, dfrA5, dfrA7, dfrA12, dfrA17 and dfrA25; aminoglycoside adenyltransferases, aadA1, aadA2, aadA5, aadA12 and aadB; aminoglycoside acetyltransferase, aac(6')-Ib; and chloramphenicol resistance gene, cmlA1. ESBL were identified in 25 (41.7%) isolates. The identified ESBL were bla(CTX-M-15), bla(CTX-M-56), bla(OXA-1), bla(SHV-1), bla(SHV-12), bla(SHV-32) and bla(TEM-1) genes. Moreover, we characterized the plasmid-mediated quinolone resistance genes, aac(6')-Ib-cr and qnrB2, which were detected in seven (11.7%) and two (3.3%) isolates, respectively. In this study various types of antibiotic resistance genes have been identified in Gram-negative bacteria from Palestinian hospitals, many of which are reported in the Middle East area for the first time. | 2009 | 19903259 |
| 1505 | 15 | 0.9757 | New insights on mcr-1-harboring plasmids from human clinical Escherichia coli isolates. Mobile colistin resistance (mcr) genes were described recently in Gram-negative bacteria including carbapenem-resistant Enterobacterales. There are ten mcr genes described in different Gram-negative bacteria, however, Escherichia coli harboring mcr-1 gene is by far the most frequent combination. In Argentina, mcr-1 gene was characterized only on plasmids belonging to IncI2 group. The aim of this work was to get new insights of mcr-1-harboring plasmids from E. coli. Eight E. coli isolates from a larger collection of 192 clinical E. coli isolates carrying the mcr-1 gene were sequenced using next generation technologies. Three isolates belonged to ST131 high-risk clone, and five to single ST, ST38, ST46, ST226, ST224, and ST405. Eight diverse mcr-1-harboring plasmids were analyzed: IncI2 (1), IncX4 (3), IncHI2/2A (3) and a hybrid IncFIA/HI1A/HI1B (1) plasmid. Plasmids belonging to the IncI2 (n = 1) and IncX4 (n = 3) groups showed high similarity with previously described plasmids. Two IncHI2/HI2A plasmids, showed high identity between them, while the third, showed several differences including additional resistance genes like tet(A) and floR. One IncFIA/H1A/H1B hybrid plasmid was characterized, highly similar to pSRC27-H, a prototype plasmid lacking mcr genes. mcr-1.5 variant was found in four plasmids with three different Inc groups: IncI2, IncHI2/HI2A and the hybrid FIA/HI1A/HI1B plasmid. mcr-1.5 variant is almost exclusively described in our country and with a high frequency. In addition, six E. coli isolates carried three allelic variants codifying for CTX-M-type extended-spectrum-β-lactamases: blaCTX-M-2 (3), blaCTX-M-65 (2), and blaCTX-M-14 (1). It is the first description of mcr-1 harboring plasmids different to IncI2 group in our country. These results represents new insights about mcr-1 harboring plasmids recovered from E. coli human samples from Argentina, showing different plasmid backbones and resistance gene combinations. | 2024 | 38408071 |
| 1136 | 16 | 0.9757 | Multidrug-Resistant Shigella Infections in Patients with Diarrhea, Cambodia, 2014-2015. We observed multidrug resistance in 10 (91%) of 11 Shigella isolates from a diarrheal surveillance study in Cambodia. One isolate was resistant to fluoroquinolones and cephalosporins and showed decreased susceptibility to azithromycin. We found mutations in gyrA, parC, β-lactamase, and mphA genes. Multidrug resistance increases concern about shigellosis treatment options. | 2016 | 27532684 |
| 1528 | 17 | 0.9757 | First Report of Coexistence of bla (SFO-1) and bla (NDM-1) β-Lactamase Genes as Well as Colistin Resistance Gene mcr-9 in a Transferrable Plasmid of a Clinical Isolate of Enterobacter hormaechei. Many antimicrobial resistance genes usually located on transferable plasmids are responsible for multiple antimicrobial resistance among multidrug-resistant (MDR) Gram-negative bacteria. The aim of this study is to characterize a carbapenemase-producing Enterobacter hormaechei 1575 isolate from the blood sample in a tertiary hospital in Wuhan, Hubei Province, China. Antimicrobial susceptibility test showed that 1575 was an MDR isolate. The whole genome sequencing (WGS) and comparative genomics were used to deeply analyze the molecular information of the 1575 and to explore the location and structure of antibiotic resistance genes. The three key resistance genes (bla (SFO-1), bla (NDM-1), and mcr-9) were verified by PCR, and the amplicons were subsequently sequenced. Moreover, the conjugation assay was also performed to determine the transferability of those resistance genes. Plasmid files were determined by the S1 nuclease pulsed-field gel electrophoresis (S1-PFGE). WGS revealed that p1575-1 plasmid was a conjugative plasmid that possessed the rare coexistence of bla (SFO-1), bla (NDM-1), and mcr-9 genes and complete conjugative systems. And p1575-1 belonged to the plasmid incompatibility group IncHI2 and multilocus sequence typing ST102. Meanwhile, the pMLST type of p1575-1 was IncHI2-ST1. Conjugation assay proved that the MDR p1575-1 plasmid could be transferred to other recipients. S1-PFGE confirmed the location of plasmid with molecular weight of 342,447 bp. All these three resistant genes were flanked by various mobile elements, indicating that the bla (SFO-1), bla (NDM-1), and mcr-9 could be transferred not only by the p1575-1 plasmid but also by these mobile elements. Taken together, we report for the first time the coexistence of bla (SFO-1), bla (NDM-1), and mcr-9 on a transferable plasmid in a MDR clinical isolate E. hormaechei, which indicates the possibility of horizontal transfer of antibiotic resistance genes. | 2021 | 34220761 |
| 1514 | 18 | 0.9756 | Widespread prevalence and molecular epidemiology of tet(X4) and mcr-1 harboring Escherichia coli isolated from chickens in Pakistan. The emergence and spread of plasmid-mediated tigecycline resistance gene tet(X4) and colistin resistance gene mcr-1 in Escherichia coli (E. coli) pose a potential threat to public health, due to the importance of colistin and tigecycline for treating serious clinical infections. However, the characterization of bacteria coharboring both genes was few reported. Here, we described the molecular epidemiology of tet(X4) and mcr-1 harboring E. coli strains of chicken origin in Pakistan, with methods including PCR, antimicrobial susceptibility testing, DNA transfer assays, plasmid replicon typing, whole-genome sequencing and bioinformatics analysis. The tet(X4) gene was identified in 36 isolates exhibiting high levels of tigecycline resistance (MICs, 16-128 mg/L). Worryingly, 24 of the 36 tet(X4)-bearing isolates were confirmed as colistin resistance, positive for plasmid-borne mcr-1. We observed the prevalence of tet(X4)-bearing IncFII plasmid with mcr-1-bearing IncI2 plasmid in 12 E. coli isolates, with a high co-transfer frequency except for one strain PK8233, in which tet(X4)- and mcr-1-bearing plasmids were non-transferable. Coexistence of tet(X4)-bearing IncFII plasmid with mcr-1-carrying multidrug-resistant (MDR) IncHI2 plasmid was also identified in 10 E. coli isolates, and a relatively low co-transfer frequency was obtained except PK8575, in which mcr-1 was non-transferable. The transferability of pPK8275-tetX in PK8275 and pPK8233-tetX in PK8233, that could transfer from E. coli J53 to C600 by conjugation, was interfered by certain factors in PK8275 and PK8233. This may provide new insights to prevent and control the spread of antibiotic resistance genes. Two strains were reported to co-carry tet(X4)-positive IncQ1 plasmid and mcr-1-positive IncI2 plasmid. Convergence of tet(X4) and mcr-1 genes in E. coli by conjugative or mobilizable plasmids may lead to potentially widespread transmission of such resistance genes, which may incur antibiotic-resistance crisis globally. | 2022 | 34599956 |
| 838 | 19 | 0.9756 | KPC and NDM-1 genes in related Enterobacteriaceae strains and plasmids from Pakistan and the United States. To characterize the genomic context of New Delhi metallo-β-lactamase-1 (NDM-1) and Klebsiella pneumoniae carbapenemase (KPC), we sequenced 78 Enterobacteriaceae isolates from Pakistan and the United States encoding KPC, NDM-1, or no carbapenemase. High similarities of the results indicate rapid spread of carbapenem resistance between strains, including globally disseminated pathogens. | 2015 | 25988236 |