RESUMEN
Colistin is a last resort antibiotic for the treatment of carbapenemase producing Klebsiella pneumoniae. The disruption of the mgrB gene by insertion sequences (ISs) is a mechanism mediating colistin resistance. Plasmids encode mobilizable IS elements which integrate into the mgrB gene in K. pneumoniae causing gene inactivation and colistin resistance. The species prevalence of mgrB-gene disrupting insertion elements ISL3 (ISKpn25), IS5 (ISKpn26), ISKpn14, and IS903B present on plasmids were assessed. IS containing plasmids were also scanned for antimicrobial resistance genes, including carbapenem resistant genes. Plasmids encoding ISs are abundant in K. pneumoniae. IS903B was found in 28 unique Inc groups, while ISKpn25 was largely carried by IncFIB(pQil) plasmids. ISKpn26 and ISKpn14 were most often found associated with IncFII(pHN7A8) plasmids. Of the 34 unique countries which contained any of the IS elements, ISKpn25 was identified from 26. ISKpn26, ISKpn14, and IS903B ISs were identified from 89.3%, 44.9%, and 23.9% plasmid samples from China. Plasmids carrying ISKpn25, ISKpn14, and ISKpn26 IS have a 4.6-, 6.0-, and 6.6-fold higher carbapenemase gene count, respectively, relative to IS903B-carrying plasmids. IS903B bearing plasmids have a 20-, 5-, and 5-fold higher environmental source isolation count relative to ISKpn25, ISKpn14, and ISKpn26 bearing plasmids. ISKpn25 present on IncFIB(pQil) sourced from clinical settings is established across multiple countries, while ISKpn26, ISKpn14, and IS903B appear most often in China. Carbapenemase presence in tandem with IS elements may help promote an extensively drug resistant profile in K. pneumoniae limiting already narrow treatment options.
Asunto(s)
Antibacterianos/farmacología , Colistina/farmacología , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/genética , Factores R/genética , Animales , Proteínas Bacterianas/genética , Elementos Transponibles de ADN/genética , Farmacorresistencia Bacteriana/genética , Humanos , PrevalenciaRESUMEN
The pandemic of antibiotic resistance represents a major human health threat demanding new antimicrobial strategies. Multiple peptide resistance factor (MprF) is the synthase and flippase of the phospholipid lysyl-phosphatidylglycerol that increases virulence and resistance of methicillin-resistant Staphylococcus aureus (MRSA) and other pathogens to cationic host defense peptides and antibiotics. With the aim to design MprF inhibitors that could sensitize MRSA to antimicrobial agents and support the clearance of staphylococcal infections with minimal selection pressure, we developed MprF-targeting monoclonal antibodies, which bound and blocked the MprF flippase subunit. Antibody M-C7.1 targeted a specific loop in the flippase domain that proved to be exposed at both sides of the bacterial membrane, thereby enhancing the mechanistic understanding of bacterial lipid translocation. M-C7.1 rendered MRSA susceptible to host antimicrobial peptides and antibiotics such as daptomycin, and it impaired MRSA survival in human phagocytes. Thus, MprF inhibitors are recommended for new antivirulence approaches against MRSA and other bacterial pathogens.
Asunto(s)
Aminoaciltransferasas/genética , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Daptomicina/farmacología , Staphylococcus aureus/efectos de los fármacos , Aminoaciltransferasas/metabolismo , Proteínas Bacterianas/metabolismo , Factores R/genética , Factores R/metabolismo , Staphylococcus aureus/enzimología , Staphylococcus aureus/genéticaRESUMEN
Corneal hysteresis and corneal resistance factor are parameters that reflect the dynamic biomechanical properties of the cornea and have been shown to be biomarkers of corneal disease. In this genome-wide association study of over 100 000 participants, we identified over 200 genetic loci, all but eight novel, significantly associated with either one or both of these traits. In addition to providing key insights into the genetic architecture underlying normal corneal function, these results identify many candidate loci in the study of corneal diseases that lead to severe visual impairment. Additionally, using Mendelian randomization, we were able to identify causal relationships between corneal biomechanics and intraocular pressure measurements, which help elucidate the relationship between corneal properties and glaucoma.
Asunto(s)
Enfermedades de la Córnea/genética , Predisposición Genética a la Enfermedad , Glaucoma de Ángulo Abierto/genética , Factores R/genética , Adulto , Anciano , Fenómenos Biomecánicos , Enfermedades de la Córnea/patología , Femenino , Estudio de Asociación del Genoma Completo , Glaucoma de Ángulo Abierto/diagnóstico por imagen , Glaucoma de Ángulo Abierto/patología , Humanos , Presión Intraocular/genética , Masculino , Persona de Mediana Edad , Tonometría OcularRESUMEN
Carbapenem-resistant Enterobacteriaceae (CRE) represent an urgent threat to human health. Here we report the application of several complementary whole-genome sequencing (WGS) technologies to characterise a hospital outbreak of blaIMP-4 carbapenemase-producing E. hormaechei. Using Illumina sequencing, we determined that all outbreak strains were sequence type 90 (ST90) and near-identical. Comparison to publicly available data linked all outbreak isolates to a 2013 isolate from the same ward, suggesting an environmental source in the hospital. Using Pacific Biosciences sequencing, we resolved the complete context of the blaIMP-4 gene on a large IncHI2 plasmid carried by all IMP-4-producing strains across different hospitals. Shotgun metagenomic sequencing of environmental samples also found evidence of ST90 E. hormaechei and the IncHI2 plasmid within the hospital plumbing. Finally, Oxford Nanopore sequencing rapidly resolved the true relationship of subsequent isolates to the initial outbreak. Overall, our strategic application of three WGS technologies provided an in-depth analysis of the outbreak.
Asunto(s)
Proteínas Bacterianas/biosíntesis , Proteínas Bacterianas/genética , Enterobacteriaceae Resistentes a los Carbapenémicos/enzimología , Enterobacteriaceae Resistentes a los Carbapenémicos/genética , Brotes de Enfermedades , Enterobacter/enzimología , Enterobacter/genética , Infecciones por Enterobacteriaceae/epidemiología , beta-Lactamasas/biosíntesis , beta-Lactamasas/genética , Quemaduras/microbiología , Enterobacteriaceae Resistentes a los Carbapenémicos/patogenicidad , Infección Hospitalaria/epidemiología , Infección Hospitalaria/microbiología , Farmacorresistencia Bacteriana Múltiple/genética , Enterobacter/aislamiento & purificación , Infecciones por Enterobacteriaceae/microbiología , Genoma Bacteriano , Humanos , Queensland/epidemiología , Factores R/genética , Ingeniería Sanitaria , Centros de Atención Terciaria , Secuenciación Completa del Genoma/métodos , Resistencia betalactámica/genéticaRESUMEN
Despite the sporadic detection of fluoroquinolone-resistant Shigella in Asia in the early 2000s and the subsequent global spread of ciprofloxacin-resistant (cipR) Shigella sonnei from 2010, fluoroquinolones remain the recommended therapy for shigellosis1-7. The potential for cipR S. sonnei to develop resistance to alternative second-line drugs may further limit future treatment options8. Here, we aim to understand the evolution of novel antimicrobial resistant (AMR) S. sonnei variants after introduction into Vietnam. We found that cipR S. sonnei displaced the resident ciprofloxacin-susceptible (cipS) lineage while rapidly acquiring additional resistance to multiple alternative antimicrobial classes. We identified several independent acquisitions of extensively drug-resistant/multidrug-resistant-inducing plasmids, probably facilitated by horizontal transfer from commensals in the human gut. By characterizing commensal Escherichia coli from Shigella-infected and healthy children, we identified an extensive array of AMR genes and plasmids, including an identical multidrug-resistant plasmid isolated from both S. sonnei and E. coli in the gut of a single child. We additionally found that antimicrobial usage may impact plasmid transfer between commensal E. coli and S. sonnei. These results suggest that, in a setting with high antimicrobial use and a high prevalence of AMR commensals, cipR S. sonnei may be propelled towards pan-resistance by adherence to outdated international treatment guidelines.
Asunto(s)
Farmacorresistencia Bacteriana Múltiple/genética , Escherichia coli/genética , Fluoroquinolonas/farmacología , Factores R/genética , Shigella sonnei/efectos de los fármacos , Shigella sonnei/genética , Niño , Ciprofloxacina/farmacología , Sistema Digestivo/microbiología , Reservorios de Enfermedades/microbiología , Disentería Bacilar/tratamiento farmacológico , Disentería Bacilar/epidemiología , Disentería Bacilar/microbiología , Epidemias , Escherichia coli/aislamiento & purificación , Genes Bacterianos , Humanos , Filogenia , Shigella sonnei/clasificación , Simbiosis/genética , Vietnam/epidemiologíaRESUMEN
Antimicrobial resistance (AMR) is currently one of the most important challenges to the treatment of bacterial infections. A critical issue to combat AMR is to restrict its spread. In several instances, bacterial plasmids are involved in the global spread of AMR. Plasmids belonging to the incompatibility group (Inc)HI are widespread in Enterobacteriaceae and most of them express multiple antibiotic resistance determinants. They play a relevant role in the recent spread of colistin resistance. We present in this report novel findings regarding IncHI plasmid conjugation. Conjugative transfer in liquid medium of an IncHI plasmid requires expression of a plasmid-encoded, large-molecular-mass protein that contains an Ig-like domain. The protein, termed RSP, is encoded by a gene (ORF R0009) that maps in the Tra2 region of the IncHI1 R27 plasmid. The RSP protein is exported outside the cell by using the plasmid-encoded type IV secretion system that is also used for its transmission to new cells. Expression of the protein reduces cell motility and enables plasmid conjugation. Flagella are one of the cellular targets of the RSP protein. The RSP protein is required for a high rate of plasmid transfer in both flagellated and nonflagellated Salmonella cells. This effect suggests that RSP interacts with other cellular structures as well as with flagella. These unidentified interactions must facilitate mating pair formation and, hence, facilitate IncHI plasmid conjugation. Due to its location on the outer surfaces of the bacterial cell, targeting the RSP protein could be a means of controlling IncHI plasmid conjugation in natural environments or of combatting infections caused by AMR enterobacteria that harbor IncHI plasmids.
Asunto(s)
Conjugación Genética/genética , Dominios de Inmunoglobulinas/genética , Factores R/genética , Secuencia de Aminoácidos , Antibacterianos/farmacología , Bacterias/genética , Proteínas Bacterianas/genética , Farmacorresistencia Microbiana/genética , Dominios de Inmunoglobulinas/fisiología , Plásmidos/genética , Salmonella/genéticaRESUMEN
No disponible
Asunto(s)
Humanos , Proteínas Bacterianas/fisiología , Carbapenémicos/farmacología , Enterobacteriaceae Resistentes a los Carbapenémicos/efectos de los fármacos , Resistencia betalactámica/genética , beta-Lactamasas/fisiología , Proteínas Bacterianas/análisis , Proteínas Bacterianas/genética , Programas de Optimización del Uso de los Antimicrobianos , Carbapenémicos/uso terapéutico , Enterobacteriaceae Resistentes a los Carbapenémicos/enzimología , Enterobacteriaceae Resistentes a los Carbapenémicos/genética , Infecciones por Enterobacteriaceae/tratamiento farmacológico , Infecciones por Enterobacteriaceae/microbiología , Factores R/genética , Infección HospitalariaRESUMEN
PURPOSE: Multidrug-resistant Klebsiella pneumoniae strains are regularly involved in hospital outbreaks. This study describes an ESBL-producing K. pneumoniae clone (ST607-K25) responsible for a nosocomial outbreak in a neonatal intensive care unit. METHODOLOGY: Fourteen strains isolated from 13 patients were included. Antimicrobial susceptibility testing was performed by the agar diffusion method. A clonal link was first investigated by fingerprinting (ERIC-PCR and REP-PCR) then confirmed by MLST. Characterization was performed by molecular detection and identification of several drug resistance and virulence determinants. RESULTS: All strains expressed the same antibiotype, combining ESBL production, fluoroquinolones and aminoglycoside resistance, except for one which remained susceptible to fluoroquinolones. Fingerprinting methods confirmed the clonal link and MLST identified a ST607 clone. Molecular investigations revealed: (I) genes encoding for two narrow-spectrum beta-lactamases (SHV-1 and TEM-1) and an ESBL (CTX-M-15); (II) absence of any chromosomal mutation in quinolone resistance-determining- regions (QRDR) of gyrA/gyrB and parC/parE genes; (III) genes encoding for three plasmid-mediated quinolone-resistance (PMQR) determinants: oqxAB (14/14), aac(6')-Ib-cr (14/14) and qnrB (13/14); (IV) production of a K25 capsule; and (V) carriage of three genes encoding for virulence factors: mrkD (type 3 fimbriae) (14/14), ybts (yersiniabactin) (12/14) and entB (enterobactin) (14/14). CONCLUSION: We described a multidrug-resistant Kp ST607 clone responsible for a nosocomial outbreak in vulnerable and premature newborns. Molecular investigations allowed us to identify several resistance factors responsible for ESBL production (CTX-M-15) and quinolone resistance (three PMQR determinants). The detection of a gene (ybtS) belonging to the high-pathogenicity island yersiniabactin could partly explain its high colonization and diffusion potential.
Asunto(s)
Antibacterianos/farmacología , Infección Hospitalaria/microbiología , Farmacorresistencia Bacteriana Múltiple , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae/aislamiento & purificación , Aminoglicósidos/farmacología , Proteínas Bacterianas/genética , Infección Hospitalaria/epidemiología , Brotes de Enfermedades , Fluoroquinolonas/farmacología , Humanos , Recién Nacido , Unidades de Cuidado Intensivo Neonatal , Infecciones por Klebsiella/epidemiología , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/enzimología , Klebsiella pneumoniae/genética , Pruebas de Sensibilidad Microbiana , Tipificación de Secuencias Multilocus , Factores R/genética , beta-Lactamasas/efectos de los fármacosAsunto(s)
Proteínas Bacterianas/fisiología , Enterobacteriaceae Resistentes a los Carbapenémicos/efectos de los fármacos , Carbapenémicos/farmacología , Resistencia betalactámica , beta-Lactamasas/fisiología , Programas de Optimización del Uso de los Antimicrobianos , Proteínas Bacterianas/análisis , Proteínas Bacterianas/genética , Enterobacteriaceae Resistentes a los Carbapenémicos/enzimología , Enterobacteriaceae Resistentes a los Carbapenémicos/genética , Carbapenémicos/uso terapéutico , Infección Hospitalaria/tratamiento farmacológico , Infección Hospitalaria/microbiología , Infecciones por Enterobacteriaceae/tratamiento farmacológico , Infecciones por Enterobacteriaceae/epidemiología , Infecciones por Enterobacteriaceae/microbiología , Humanos , Factores R/genética , Resistencia betalactámica/genética , beta-Lactamasas/análisis , beta-Lactamasas/genéticaRESUMEN
INTRODUCTION: To characterize OXA-48 carbapenemase-producing Klebsiella pneumoniae strains isolated after an increase in carbapenem resistance in Catalonia. METHODOLOGY: K. pneumoniae identification, antimicrobial susceptibility studies, the Modified Hodge Test method, amplification of antimicrobial resistance genes (against ß-lactamases, quinolones and aminoglycosides), molecular typing (by PFGE and MLST), conjugation assays, plasmid characterization (PBRT-PCR and Southern blot), a description of mobile genetic elements and statistical analysis were done. RESULTS: OXA-48 was the only carbapenemase detected, with a prevalence of 1.9%. The blaOXA-48 gene was located in an IncL conjugative plasmid of 62kb and integrated into the transposons Tn1999.2 (91.7%) or Tn1999.1. Five PFGE profiles (A to E) were found, which exactly matched the MLST: ST101, ST17, ST1233, ST14 and ST405, respectively. ST1233 is described here for the first time. K. pneumoniae OXA-48-producing strains were also CTX-M-15 carriers, some producing OXA-1 and TEM-1 penicillinases. The acquired qnrB66 and qnrB1 and aac(3')-IIa, aac(6')-Ib genes were also identified. CONCLUSION: The K. pneumoniae ST405 clone has played an important role in the growing prevalence of OXA-48 in Catalonia. All clones described preserved the blaOXA-48 genetic environment and mobile genetic elements (Tn1999). Notably, the three strains with minor sequence types in this study are not multiresistant strains. These strains are expanding in elderly patients (average age of 76 years) with serious underlying diseases, mainly women (61.2%).
Asunto(s)
Farmacorresistencia Bacteriana Múltiple/genética , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae/genética , Resistencia betalactámica/genética , beta-Lactamasas/genética , Infecciones Comunitarias Adquiridas/epidemiología , Infecciones Comunitarias Adquiridas/microbiología , Conjugación Genética , Infección Hospitalaria/epidemiología , Infección Hospitalaria/microbiología , Elementos Transponibles de ADN/genética , Humanos , Infecciones por Klebsiella/epidemiología , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/enzimología , Klebsiella pneumoniae/aislamiento & purificación , Pruebas de Sensibilidad Microbiana , Epidemiología Molecular , Estudios Prospectivos , Factores R/genética , España/epidemiología , beta-Lactamasas/análisisRESUMEN
Objectives: To identify the prevalence and the types of Neisseria gonorrhoeae (NG) resistance plasmids-mediated penicillin (PPNG) and tetracycline (TRNG), the ciprofloxacin resistance (CRNG), and related risk factors of each types of resistance. Methods: The beta-lactamase-producing plasmid types (Africa, Asia, and Toronto), tetM tetracycline resistance plasmid types (America and Dutch), and the determination of the Ser-91 mutation of GyrA were detected by specifics PCRs on 149 diagnosed NG positives samples followed by Hinf1 digestion for tetM and gyrA mutation. Results: 135 (90.1%) samples showed a profile of molecular resistance to at least one antibiotic with predominance of ciprofloxacin resistance. In fact, 36 (24.2%) and 69 (46.3%) cases harbored PPNG and TRNG, respectively, and 116 (77.9%) cases showed the mutation Ser-91 of GyrA (CRNG). From a total of 36 PPNG isolates, the Toronto, Asian, and Toronto/Asian types were detected in 13 (36.1%), 10 (27.8%), and 13 (36.1%) cases, respectively, whereas the African type was not detected. In addition, the American type of TRNG was detected in 92.8% (64/69) of cases, while the Dutch type was detected in 7.2% (5/69) of cases. The association of demographics and clinical variables with NG resistance to ciprofloxacin, penicillin, and tetracycline was studied and the risk factors have been determined. Conclusion: Resistance to penicillin, tetracycline, and ciprofloxacin among NG samples positives remained at high levels in Morocco as determined by molecular profile. So, the use of molecular tools for NG antimicrobial resistance detection can help in the management and spread limitation of this infection.
Asunto(s)
Antibacterianos/farmacología , Farmacorresistencia Bacteriana/genética , Neisseria gonorrhoeae/efectos de los fármacos , Neisseria gonorrhoeae/genética , Adulto , Anciano , Femenino , Gonorrea/tratamiento farmacológico , Gonorrea/microbiología , Humanos , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Marruecos/epidemiología , Mutación , Neisseria gonorrhoeae/enzimología , Resistencia a las Penicilinas/genética , Penicilinas/farmacología , Plásmidos/genética , Reacción en Cadena de la Polimerasa , Prevalencia , Factores R/genética , Resistencia a la Tetraciclina/genética , Adulto Joven , beta-Lactamasas/genéticaRESUMEN
The aim of this study was to use single-molecule, nanopore sequencing to explore the genomic environment of the resistance determinants in a multidrug-resistant (MDR) strain of enteroaggregative Escherichia coli serotype O51â:âH30, sequence type (ST) 38. Sequencing was performed on the MinION Flow cell MIN-106 R9.4. Nanopore raw FAST5 reads were base-called using Albacore v1.2.1, converted to FASTA and FASTQ formats using Poretools v0.6.0, and assembled using Unicycler v0.4.2, combining the long-read sequencing data with short-read data produced by Illumina sequencing. The genome was interrogated against an antimicrobial resistance (AMR) gene reference database using blast. The majority of the 12 AMR determinants identified were clustered together on the chromosome at three separate locations flanked by integrases and/or insertion elements [region 1 -catA, blaOXA-1, aac(6')-Ib-cr, tetA and blaCTX-M-15; region 2 - dfrA1 and aadA1; region 3 - catA, blaTEM-1, tetA and sul2]. AMR determinants located outside these three regions were a chromosomally encoded blaCMY-16, mutations in gyrA and parC, and two plasmid-encoded AMR determinants, blaOXA-181 and qnrS1 located on the same IncX3 plasmid. Long-read analysis of whole genome sequencing data identified mobile genetic elements on which AMR determinants were located and revealed the combination of different AMR determinants co-located on the same mobile element. These data contribute to a better understanding of the transmission of co-located AMR determinants in MDR E. coli causing gastrointestinal and extra-intestinal infections.
Asunto(s)
Farmacorresistencia Bacteriana Múltiple/genética , Proteínas de Escherichia coli/genética , Escherichia coli/genética , Genoma Bacteriano , Nanoporos , Análisis de Secuencia de ADN , Escherichia coli/patogenicidad , Factores R/genéticaRESUMEN
The first extensively drug resistant (XDR) Neisseria gonorrhoeae strain with high resistance to the extended-spectrum cephalosporin ceftriaxone was identified in 2009 in Japan, but no other strain with this antimicrobial-resistance profile has been reported since. However, surveillance to date has been based on phenotypic methods and sequence typing, not genome sequencing. Therefore, little is known about the local population structure at the genomic level, and how resistance determinants and lineages are distributed and evolve. We analysed the whole-genome sequence data and the antimicrobial-susceptibility testing results of 204 strains sampled in a region where the first XDR ceftriaxone-resistant N. gonorrhoeae was isolated, complemented with 67 additional genomes from other time frames and locations within Japan. Strains resistant to ceftriaxone were not found, but we discovered a sequence type (ST)7363 sub-lineage susceptible to ceftriaxone and cefixime in which the mosaic penA allele responsible for reduced susceptibility had reverted to a susceptible allele by recombination. Approximately 85â% of isolates showed resistance to fluoroquinolones (ciprofloxacin) explained by linked amino acid substitutions at positions 91 and 95 of GyrA with 99â% sensitivity and 100â% specificity. Approximately 10â% showed resistance to macrolides (azithromycin), for which genetic determinants are less clear. Furthermore, we revealed different evolutionary paths of the two major lineages: single acquisition of penA X in the ST7363-associated lineage, followed by multiple independent acquisitions of the penA X and XXXIV in the ST1901-associated lineage. Our study provides a detailed picture of the distribution of resistance determinants and disentangles the evolution of the two major lineages spreading worldwide.
Asunto(s)
Antibacterianos , Farmacorresistencia Bacteriana Múltiple/genética , Evolución Molecular , Genoma Bacteriano , Neisseria gonorrhoeae/genética , Factores R/genética , Gonorrea/genética , Humanos , JapónRESUMEN
OBJECTIVES: Shewanella algae is an environmental marine bacterium and an emerging opportunistic human pathogen. Moreover, there are increasing reports of strains showing multidrug resistance, particularly carbapenem-resistant isolates. Although S. algae has been found in bivalve shellfish aquaculture, there is very little genome-wide data on resistance determinants in S. algae from shellfish. The aim of this study was to determine the whole genome sequence of carbapenem-resistant S. algae strain AC isolated from small abalone in Taiwan. METHODS: Bacterial genomic DNA was sequenced using an Illumina MiSeq platform with 250-bp paired-end reads. De novo genome assembly was performed using Velvet v.1.2.07. The whole genome was annotated and several candidate genes for antimicrobial resistance were identified. RESULTS: The genome size was calculated at 4751156bp, with a mean G+C content of 53.09%. A total of 4164 protein-coding sequences, 7 rRNAs, 85 tRNAs and 5 non-coding RNAs were identified. The genome contains genes associated with resistance to ß-lactams, trimethoprim, tetracycline, colistin and quinolones. Multiple efflux pump genes were also detected. CONCLUSION: Small abalone is a potential source of foodborne drug-resistant S. algae. The genome sequence of carbapenem-resistant S. algae strain AC isolated from small abalone will provide valuable information for further study of the dissemination of resistance genes at the human-animal interface.
Asunto(s)
Antibacterianos/farmacología , Carbapenémicos/farmacología , Farmacorresistencia Bacteriana Múltiple/genética , Genoma Bacteriano , Mariscos/microbiología , Shewanella/efectos de los fármacos , Shewanella/genética , Animales , ADN Bacteriano/genética , Pruebas de Sensibilidad Microbiana , Factores R/genética , Análisis de Secuencia de ADN , Taiwán , Secuenciación Completa del Genoma , beta-Lactamasas/genéticaRESUMEN
The capture of antimicrobial resistance genes (ARGs) by mobile genetic elements (MGEs) plays a critical role in resistance acquisition for human-associated bacteria. Although aquaculture environments are recognized as important reservoirs of ARGs, intra- and intercellular mobility of MGEs discovered in marine organisms is poorly characterized. Here, we show a new pattern of interspecies ARGs transfer involving a 'non-conjugative' integrative element. To identify active MGEs in a Vibrio ponticus isolate, we conducted whole-genome sequencing of a transconjugant obtained by mating between Escherichia coli and Vibrio ponticus. This revealed integration of a plasmid (designated pSEA1) into the chromosome, consisting of a self-transmissible plasmid backbone of the MOBH group, ARGs, and a 13.8-kb integrative element Tn6283. Molecular genetics analysis suggested a two-step gene transfer model. First, Tn6283 integrates into the recipient chromosome during suicidal plasmid transfer, followed by homologous recombination between the Tn6283 copy in the chromosome and that in the newly transferred pSEA1. Tn6283 is unusual among integrative elements in that it apparently does not encode transfer function and its excision barely generates unoccupied donor sites. Thus, its movement is analogous to the transposition of insertion sequences rather than to that of canonical integrative and conjugative elements. Overall, this study reveals the presence of a previously unrecognized type of MGE in a marine organism, highlighting diversity in the mode of interspecies gene transfer.
Asunto(s)
Organismos Acuáticos/fisiología , Farmacorresistencia Bacteriana/genética , Escherichia coli/fisiología , Factores R/genética , Vibrio/fisiología , Acuicultura , Organismos Acuáticos/efectos de los fármacos , Organismos Acuáticos/genética , Escherichia coli/efectos de los fármacos , Escherichia coli/genética , Transferencia de Gen Horizontal , Vibrio/efectos de los fármacos , Vibrio/genética , Secuenciación Completa del GenomaAsunto(s)
Proteínas Bacterianas/genética , Colistina/farmacología , Infección Hospitalaria/transmisión , Contaminación de Medicamentos , Etanolaminofosfotransferasa/genética , Desinfectantes para las Manos , Transmisión de Enfermedad Infecciosa de Paciente a Profesional , Transmisión de Enfermedad Infecciosa de Profesional a Paciente , Infecciones por Klebsiella/transmisión , Klebsiella pneumoniae/aislamiento & purificación , Anciano de 80 o más Años , Células Clonales , Trazado de Contacto , Infección Hospitalaria/epidemiología , Infección Hospitalaria/microbiología , Farmacorresistencia Bacteriana Múltiple/genética , Femenino , Francia/epidemiología , Genes Bacterianos , Higiene de las Manos , Humanos , Infecciones por Klebsiella/epidemiología , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae/enzimología , Klebsiella pneumoniae/genética , Persona de Mediana Edad , Factores R/genéticaRESUMEN
OBJECTIVE: Colistin resistance has emerged worldwide and has been threatening the efficacy of one of the last-resort antimicrobials used for treatment of multidrug resistant Gram-negative bacteria. While five colistin resistance genes (mcr-1, mcr-2, mcr-3, mcr-4 and mcr-5) have been described, few data are available on the prevalence of mcr-genes other than mcr-1 in human samples. RESULTS: In this study, the presence of five currently described colistin resistance genes (mcr 1-5) in vaginal swabs of women undergoing infertility evaluation was reported. Most samples were found to be positive for the mcr-4 (12.7%), followed by two for the mcr-2 (1.5%), two for the mcr-3 (1.5%), one for the mcr-1 (0.7%), and one for the mcr-5 (0.7%). Phylogenetic comparison demonstrated identical (mcr-1, mcr-2, mcr-3, mcr-5) or similar (mcr-4) nucleotide sequences of human samples and those of animal origins from the same city, suggesting the potential transmission of mcr genes from animals to humans. This is the first detection of mcr-2, mcr-4 and mcr-5 genes in human samples, and warrants further research to determine the spread of the mcr genes and elucidate the full epidemiology of colistin resistance genes in humans.
Asunto(s)
Antibacterianos/farmacología , Colistina/farmacología , Farmacorresistencia Bacteriana/genética , Genes Bacterianos/genética , Factores R/genética , Vagina/microbiología , Adulto , Femenino , HumanosRESUMEN
In order to expedite the discovery of genes coding for either drug targets or antibiotic resistance, we have developed a functional genomic strategy termed Plas-Seq. This technique involves coupling a multicopy suppressor library to next-generation sequencing. We generated an Escherichia coli plasmid genomic library that was transformed into E. coli. These transformants were selected step by step using 0.25× to 2× minimum inhibitory concentrations for ceftriaxone, gentamicin, levofloxacin, tetracycline or trimethoprim. Plasmids were isolated at each selection step and subjected to Illumina sequencing. By searching for genomic loci whose sequencing coverage increased with antibiotic pressure we were able to detect 48 different genomic loci that were enriched by at least one antibiotic. Fifteen of these loci were studied functionally, and we showed that 13 can decrease the susceptibility of E. coli to antibiotics when overexpressed. These genes coded for drug targets, transcription factors, membrane proteins and resistance factors. The technique of Plas-Seq is expediting the discovery of genes associated with the mode of action or resistance to antibiotics and led to the isolation of a novel gene influencing drug susceptibility. It has the potential for being applied to novel molecules and to other microbial species.
Asunto(s)
Antibacterianos/farmacología , Farmacorresistencia Bacteriana Múltiple/genética , Escherichia coli/efectos de los fármacos , Escherichia coli/genética , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Sistemas CRISPR-Cas , Ceftriaxona/farmacología , Proteínas de Unión al ADN/genética , Proteínas de Escherichia coli/genética , Técnicas de Silenciamiento del Gen , Genes Bacterianos/genética , Gentamicinas/farmacología , Levofloxacino/farmacología , Proteínas de la Membrana/genética , Pruebas de Sensibilidad Microbiana , Plásmidos/genética , Factores R/genética , Tetraciclina/farmacología , Factores de Transcripción/genética , Trimetoprim/farmacologíaAsunto(s)
Antiportadores/genética , Proteínas Bacterianas/genética , Farmacorresistencia Bacteriana Múltiple/genética , Pseudomonas aeruginosa/genética , Factores R/genética , beta-Lactamasas/genética , Antibacterianos/farmacología , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Pancreatitis/microbiología , Infecciones por Pseudomonas/microbiología , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/aislamiento & purificación , Resistencia a la Tetraciclina/genéticaRESUMEN
The objective of this study was to investigate the molecular mechanisms explaining the multidrug-resistant (MDR) phenotype found in a novel clinical Shewanella sp. strain (Shew256) recovered from a diabetic patient. Whole-genome shotgun sequencing was performed using Illumina MiSeq-I and Nextera XT DNA library. De novo assembly was performed with SPAdes. RAST Server was used to predict the open-reading frames and the predictions were confirmed using BLAST. Further genomic analysis was carried out using average nucleotide identity (ANI), ACT (Artemis), OrthoMCL, ARG-ANNOT, ISfinder, PHAST, tRNAscan-SE, plasmidSPAdes, PlasmidFinder and MAUVE. PCR and plasmid extraction were also performed. Genomic analysis revealed a total of 456 predicted genes unique to Shew256 compared with other Shewanella genomes. Moreover, the presence of different resistance genes, including blaPER-2, was found. A complex class 1 integron containing the ISCR1 gene, disrupted by two putative transposase genes, was identified. Furthermore, other resistance genes, a transposon containing aph(3'), insertion sequences, phages and non-coding RNAs were also found. In conclusion, evidence of acquisition of resistance genes and mobile elements that could explain the MDR phenotype were observed. This Shewanella sp. represents a prime example of how antibiotic resistance determinants can be acquired by uncommon pathogens.