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1.
J Chem Phys ; 158(19)2023 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-37184019

RESUMEN

We investigate quasi-two-dimensional buckled colloidal monolayers on a triangular lattice with tunable depletion interactions. Without depletion attraction, the experimental system provides a colloidal analog of the well-known geometrically frustrated Ising antiferromagnet [Y. Han et al., Nature 456, 898-903 (2008)]. In this contribution, we show that the added depletion attraction can influence both the magnitude and sign of an Ising spin coupling constant. As a result, the nearest-neighbor Ising "spin" interactions can be made to vary from antiferromagnetic to para- and ferromagnetic. Using a simple theory, we compute an effective Ising nearest-neighbor coupling constant, and we show how competition between entropic effects permits for the modification of the coupling constant. We then experimentally demonstrate depletion-induced modification of the coupling constant, including its sign, and other behaviors. Depletion interactions are induced by rod-like surfactant micelles that change length with temperature and thus offer means for tuning the depletion attraction in situ. Buckled colloidal suspensions exhibit a crossover from an Ising antiferromagnetic to paramagnetic phase as a function of increasing depletion attraction. Additional dynamical experiments reveal structural arrest in various regimes of the coupling-constant, driven by different mechanisms. In total, this work introduces novel colloidal matter with "magnetic" features and complex dynamics rarely observed in traditional spin systems.

2.
Emerg Infect Dis ; 28(7): 1437-1441, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35731181

RESUMEN

Unidentified Mycobacterium species are sometimes detected in respiratory specimens. We identified a novel Tsukamurella species (Tsukamurella sp. TY48, RIMD 2001001, CIP 111916T), Tsukamurella toyonakaense, from a patient given a misdiagnosis of nontuberculous mycobacterial pulmonary disease caused by unidentified mycobacteria. Genomic identification of this Tsukamurella species helped clarify its clinical characteristics and epidemiology.


Asunto(s)
Enfermedades Pulmonares , Infecciones por Mycobacterium no Tuberculosas , Mycobacterium , Humanos , Enfermedades Pulmonares/diagnóstico , Enfermedades Pulmonares/epidemiología , Enfermedades Pulmonares/microbiología , Mycobacterium/genética , Infecciones por Mycobacterium no Tuberculosas/diagnóstico , Infecciones por Mycobacterium no Tuberculosas/epidemiología , Infecciones por Mycobacterium no Tuberculosas/microbiología , Micobacterias no Tuberculosas/genética
3.
J Antimicrob Chemother ; 77(5): 1237-1246, 2022 04 27.
Artículo en Inglés | MEDLINE | ID: mdl-35137119

RESUMEN

OBJECTIVES: Carbapenemase-producing Enterobacterales (CPE) pose serious threats to public health. Compared with clinical CPE, the genetic characteristics of environmental CPE are not well understood. This study aimed to characterize the genetic determinants of carbapenem resistance in CPE isolated from environmental waters in Japan. METHODS: Eighty-five water samples were collected from rivers and a lake in Japan. CPE were identified using selective media, and genome sequencing was performed for the obtained isolates (n = 21). RESULTS: Various rare/novel carbapenemases were identified: GES-5 in Raoultella planticola (n = 1), FRI-8 and FRI-11 in Enterobacter spp. (n = 8), IMI-22 and IMI-23 in Serratia ureilytica (n = 3), and SFC-1, SFC-2 and SFH-1 in Serratia fonticola (n = 9). Genomes of 11 isolates could be closed, allowing the elucidation of the genetic contexts of the carbapenemase genes. The blaGES-5 gene was located within a class 1 integron, In2071 (cassette array, blaGES-5-aacA3-aadA16), on a 33 kb IncP6 plasmid. The blaFRI-8 genes were carried on IncFII(Yp) plasmids ranging in size from 191 kb to 244 kb, and the blaFRI-11 genes were carried on 70 kb and 74 kb IncFII(pECLA)/IncR plasmids. The blaIMI-22 and blaIMI-23 genes were co-located on a 107 kb plasmid. The blaSFC and blaSFH-1 genes were found on putative genomic islands inserted at tRNA-Phe genes in chromosomes. CONCLUSIONS: This study revealed the presence of rare/novel carbapenemases among CPE in aquatic environments, suggesting that the environment may act as a potential reservoir of these minor carbapenemases.


Asunto(s)
Proteínas Bacterianas , beta-Lactamasas , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Japón , Pruebas de Sensibilidad Microbiana , Plásmidos , beta-Lactamasas/genética
4.
Virol J ; 19(1): 24, 2022 02 03.
Artículo en Inglés | MEDLINE | ID: mdl-35115008

RESUMEN

INTRODUCTION: In this work, six SARS-CoV-2-specific antibody assays were evaluated, namely, two pan-immunoglobulin (pan-Ig) assays [Roche Elecsys Anti-SARS-CoV-2 (named "Elecsys" in this study) and the PerkinElmer SuperFlex™ Anti-SARS-CoV-2 Ab Assay (SuperFlex_Ab)], two IgM assays [SuperFlex™ Anti-SARS-CoV-2 IgM Assay (SuperFlex_IgM) and YHLO iFlash-SARS-CoV-2 IgM (iFlash_IgM)], and two IgG assays [SuperFlex™ Anti-SARS-CoV-2 IgG Assay (SuperFlex_IgG) and iFlash-SARS-CoV-2 IgG (iFlash_IgG)]. Combination assays of SuperFlex™ (SuperFlex_any) and iFlash (iFlash_any) were also evaluated. METHODS: A total of 438 residual serum samples from 54 COVID-19 patients in the COVID-19 group and 100 samples from individuals without evidence of SARS-CoV-2 infection in the negative control group were evaluated. RESULTS: In the early stage of COVID-19 infection, within 14 days of symptom onset, the seropositive rate was lower than that of the late stage 15 days after onset (65.4% vs 99.6%). In the total period, the pan-Ig and IgG assays had higher sensitivity (90.8-95.3%) than the IgM assays (36.5-40.7%). SuperFlex_Ab and SuperFlex_any had higher sensitivity than Elecsys and SuperFlex_IgG (p < 0.05). The specificity of all the assays was 100%, except for SuperFlex_IgM (99.0%). The concordance rate between each assay was higher (96.4-100%) in the late stage than in the early stage (77.4-98.1%). CONCLUSION: For the purpose of COVID-19 diagnosis, antibody testing should be performed 15 days after onset. For the purpose of epidemiological surveillance, highly sensitive assays should be used as much as possible, such as SuperFlex_Ab, iFlash_IgG and their combination. IgM assays were not suitable for these purposes.


Asunto(s)
Anticuerpos Antivirales/análisis , Prueba Serológica para COVID-19/métodos , COVID-19 , COVID-19/diagnóstico , Humanos , Inmunoglobulina G/análisis , Inmunoglobulina M/análisis , SARS-CoV-2/inmunología , Sensibilidad y Especificidad
5.
Artículo en Inglés | MEDLINE | ID: mdl-35604945

RESUMEN

A slowly growing mycobacteria, identified as strain TY59T, was isolated from sputum of an elderly man with pneumonia. Sequencing of the 16S rRNA gene indicated that this strain was similar to members of the Mycobacterium avium complex and closely related species. Strain TY59T has highest 16S rRNA gene sequence similarities to the type strains of Mycobacterium colombiense (99.80 % sequence similarity), Mycobacterium vulneris (99.74 %), Mycobacterium timonense (99.54 %), Mycobacterium avium subsp. avium (99.54 %) and Mycobacterium avium subsp. silvaticum (99.54 %). Analysis of the internal transcribed spacer (ITS) and DNA-directed RNA polymerase subunit beta (rpoB) sequences gave similar results to the 16S rRNA gene analysis. The closest species to strain TY59T were M. colombiense and M. vulneris with 97.90-98.25 % identity in ITS and 96.4-96.6 % in rpoB. The strain's 65 kDa heat shock protein (hsp65) gene was different from those of M. vulneris, M. colombiense and M. avium subsp. silvaticum with 72.4-74.2 % identity. Average nucleotide identity results showed a 93.4 % match to M. vulneris as the maximum value. Phenotypically, the non-chromogenicity, rough colonies, growth at 42 °C, negative results for nitrate reduction, ß-glucosidase and Tween 80 hydrolysis, and positive results for catalase activity set this strain apart from closely related species. We propose that Mycobacterium senriense sp. nov. is a novel species of slowly growing mycobacteria. The type strain is TY59T (RIMD 1371001T=CIP 111917T).


Asunto(s)
Infecciones por Mycobacterium , Mycobacterium , Anciano , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , ARN Polimerasas Dirigidas por ADN/genética , Ácidos Grasos/química , Humanos , Masculino , Infecciones por Mycobacterium/diagnóstico , Infecciones por Mycobacterium/microbiología , Complejo Mycobacterium avium , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Esputo/microbiología
6.
J Infect Chemother ; 27(3): 503-506, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33214070

RESUMEN

INTRODUCTION: The real-time PCR assay Xpert Carba-R and the lateral flow immunoassay NG-Test CARBA5 were developed to detect 5 types of carbapenemase genes (blaIMP, blaKPC, blaVIM, blaOXA-48, and blaNDM). METHODS: We compared the diagnostic performance, turn-around time, and cost of these assays. Carbapenemase genes were defined using the Carba NP test, modified Carbapenem Inactivation Methods (mCIM), multiplex PCR, and whole-genome sequencing. We included clinical Enterobacterales isolates (n = 36) and nonfermenting gram-negative bacilli isolates (n = 17) collected from 16 acute-care hospitals in the Kinki region of Japan. RESULTS: Twenty-six of these 53 isolates were positive according to both of the Carba NP test and mCIM and, contained the following carbapenemase genes: blaIMP-1 (n = 3), blaIMP-6 (n = 1), blaIMP-19 (n = 12), blaIMP-26 (n = 1), blaIMP-41 (n = 2), blaIMP-66 (n = 2), blaNDM-1 (n = 3), and blaVIM-2 (n = 2). All of the remaining 27 isolates were negative according to the Carba NP test, mCIM, and multiplex PCR. The specificities of both assays were 100%. The sensitivity of the Xpert Carba-R assay was as low as 53.8% and that of the NG-Test CARBA5 was 92.3% because the former failed to detect all isolates with blaIMP-19 (n = 12) and the latter failed to detect isolates with blaIMP-66 (n = 2). Both assays can easily be performed in less than 5 min. CONCLUSIONS: The NG-Test CARBA5 assay was superior with regard to assay time and cost per sample. We propose the use of the NG-Test CARBA5 assay in clinical laboratories where IMP-type carbapenemases are endemic.


Asunto(s)
beta-Lactamasas , Humanos , Proteínas Bacterianas/genética , beta-Lactamasas/genética , Japón , Sensibilidad y Especificidad
7.
Artículo en Inglés | MEDLINE | ID: mdl-30455244

RESUMEN

We investigated the epidemiology and resistance mechanisms of ampicillin-sulbactam-nonsusceptible Escherichia coli, focusing on the role of the TEM-1 ß-lactamase. We collected all nonduplicate E. coli clinical isolates at 10 Japanese hospitals during December 2014 and examined their antimicrobial susceptibility, ß-lactamases, TEM-1 transferability, TEM-1 ß-lactamase activity, outer membrane protein profile, membrane permeability, and clonal genotypes. Among the 329 isolates collected, 95 were ampicillin-sulbactam nonsusceptible. Of these ampicillin-sulbactam-nonsusceptible isolates, ß-lactamases conferring resistance to sulbactam, such as AmpC, were present in 33%. Hyperproduction of sulbactam-susceptible ß-lactamases, TEMs with a strong promoter, were rare (5%). The remaining 59 isolates (62%) had only sulbactam-susceptible ß-lactamases, including TEM-1 with a wild-type promoter (n = 28), CTX-Ms (n = 13), or both (n = 17). All 45 transconjugants from 96 donors with TEM-1 had higher ampicillin-sulbactam MICs (4 to 96 mg/liter) than the recipient (2 mg/liter). In donors with only TEM-1, TEM-1 activity correlated with the 50% inhibitory concentration of sulbactam and ampicillin-sulbactam MICs. The decreased membrane permeation of sulbactam was associated with an increased ampicillin-sulbactam MIC. The reduced permeation was partly attributable to deficient outer membrane proteins, which were observed in 57% of the ampicillin-sulbactam-nonsusceptible isolates with only TEM-1 and a wild-type promoter. Sequence type 131 (ST131) was the most common clonal type (52%). TEM-1 with a wild-type promoter primarily contributed to ampicillin-sulbactam nonsusceptibility in E. coli, with the partial support of other mechanisms, such as reduced permeation. Conjugative TEM-1 and the clonal spread of ST131 may contribute to the prevalence of Japanese ampicillin-sulbactam-nonsusceptible isolates.


Asunto(s)
Ampicilina/farmacología , Antibacterianos/farmacología , Escherichia coli/metabolismo , Sulbactam/farmacología , beta-Lactamasas/metabolismo , Escherichia coli/efectos de los fármacos , Japón , Pruebas de Sensibilidad Microbiana , beta-Lactamasas/genética
8.
Med Mycol ; 57(8): 997-1003, 2019 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-30690480

RESUMEN

The prevalence of azole-resistant Aspergillus fumigatus (ARAF) in Japan is unclear. We aimed to investigate the epidemiology of clinically isolated Aspergillus species and the frequency of azole resistance in Aspergillus species, particularly Aspergillus fumigatus, in the Kyoto and Shiga regions of Japan. Strains of clinically isolated Aspergillus species were prospectively collected from nine acute care hospitals. Species identification was performed by DNA sequence analysis, and all strains were subjected to antifungal susceptibility testing. Sequencing of the Aspergillus cyp51A gene and promoter region and genotyping by short tandem repeats were performed for ARAF isolates. A total of 149 strains were collected, and 130 strains were included for the subsequent analysis after the exclusion of duplicate isolates. The most commonly isolated species was Aspergillus fumigatus, accounting for 43.1% (56 isolates) overall, and seven (12.7%) of 55 strains of A. fumigatus were azole-resistant. Azole-resistance of other Aspergillus species were also found that two (22.2%) of nine strains of A. tubingensis and two (28.6%) of seven strains of A. flavus were azole-resistant. DNA sequence analysis of the ARAF strains revealed that two carried the cyp51A TR34/L98H mutation, one carried G448S, one carried M220I, and three had no relevant mutations (wild type). Genotyping and phylogenetic analyses showed that the TR34/L98H strains were clustered with the strains from the Netherlands and France. These data suggest the emergence of ARAF with TR34/L98H in Japan, and continuous surveillance will be important to identify trends in resistance.


Asunto(s)
Antifúngicos/farmacología , Aspergilosis/epidemiología , Aspergilosis/microbiología , Aspergillus/efectos de los fármacos , Azoles/farmacología , Farmacorresistencia Fúngica , Mutación , Aspergillus/clasificación , Aspergillus/aislamiento & purificación , Análisis por Conglomerados , Monitoreo Epidemiológico , Genotipo , Humanos , Japón/epidemiología , Epidemiología Molecular , Filogenia , Prevalencia , Estudios Prospectivos , Análisis de Secuencia de ADN
9.
Artículo en Inglés | MEDLINE | ID: mdl-29784850

RESUMEN

A multidrug-resistant (MDR) Pseudomonas fulva strain was isolated in 2006 from a urine sample. The isolate harbored the blaIMP-1 gene, which was located in a chromosomal Tn402-like class 3 integron as a gene cassette array of aacA31-fosE-blaIMP-1 Two mutations in gyrA and one mutation in parC were detected in quinolone-resistance-determining regions (QRDRs). We report a full-length, novel, blaIMP-1-carrying class 3 integron. This integron, together with mutations in QRDRs, could have influenced the MDR phenotype.


Asunto(s)
Integrones/genética , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/genética , beta-Lactamasas/genética , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Farmacorresistencia Bacteriana Múltiple/genética , Pruebas de Sensibilidad Microbiana , Mutación/genética
10.
Artículo en Inglés | MEDLINE | ID: mdl-29483120

RESUMEN

Wastewater is considered a major source of antibiotic-resistant bacteria released into the environment. Here, we characterized carbapenemase-producing Enterobacteriaceae (CPE) in wastewater by whole-genome analysis. Wastewater samples (n = 40) were collected from municipal wastewater treatment plants and hospital wastewater in Japan and Taiwan. Samples were screened for CPE using selective media, and the obtained isolates were sequenced using an Illumina MiSeq. The isolates (n = 45) included the following microorganisms: Klebsiella quasipneumoniae (n = 12), Escherichia coli (n = 10), Enterobacter cloacae complex (n = 10), Klebsiella pneumoniae (n = 8), Klebsiella variicola (n = 2), Raoultella ornithinolytica (n = 1), Citrobacter freundii (n = 1), and Citrobacter amalonaticus (n = 1). Among the 45 isolates, 38 harbored at least one carbapenemase-encoding gene. Of these, the blaGES (blaGES-5, blaGES-6, and blaGES-24) genes were found in 29 isolates. The genes were situated in novel class 1 integrons, but the integron structures were different between the Japanese (In1439 with blaGES-24 and In1440 with blaGES-5) and Taiwanese (In1441 with blaGES-5 and In1442 with blaGES-6) isolates. Other carbapenemase-encoding genes (blaVIM-1, blaNDM-5, blaIMP-8, blaIMP-19, and blaKPC-2) were found in one to three isolates. Notably, class 1 integrons previously reported among clinical isolates obtained in the same regions as the present study, namely, In477 with blaIMP-19 and In73 with blaIMP-8, were found among the Japanese and Taiwanese isolates, respectively. The results indicate that CPE with various carbapenemase-encoding genes in different genetic contexts were present in biologically treated wastewater, highlighting the need to monitor for antibiotic resistance in wastewater.


Asunto(s)
Proteínas Bacterianas/metabolismo , Enterobacteriaceae/enzimología , beta-Lactamasas/metabolismo , Proteínas Bacterianas/genética , Enterobacteriaceae/genética , Integrones/genética , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/aislamiento & purificación , Pruebas de Sensibilidad Microbiana , Aguas Residuales/microbiología , beta-Lactamasas/genética
11.
J Infect Chemother ; 24(6): 443-448, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29501469

RESUMEN

The early detection of Shiga toxin-producing Escherichia coli (STEC) is important for early diagnosis and preventing the spread of STEC. Although the confirmatory test for STEC should be based on the detection of Shiga toxin using molecular analysis, isolation permits additional characterization of STEC using a variety of methods, including O:H serotyping. The conventional slide agglutination O-antigen serogrouping used in many clinical laboratories is laborious and time-consuming. Surface plasmon resonance (SPR)-based immunosensors are commonly used to investigate a large variety of bio-interactions such as antibody/antigen, peptide/antibody, DNA/DNA, and antibody/bacteria interactions. SPR imaging (SPRi) is characterized by multiplexing capabilities for rapidly screening (approximately 100 to several hundred sensorgrams in parallel) molecules. SPRi-based O-antigen serogrouping method for STEC was recently developed by detecting the interactions between O-antigen-specific antibodies and bacterial cells themselves. The aim of this study was to evaluate its performance for E. coli serogrouping using clinical STEC isolates by comparing the results of slide agglutination tests. We tested a total of 188 isolates, including O26, O45, O91, O103, O111, O115, O121, O128, O145, O157, and O159. The overall sensitivity of SPRi-based O-antigen serogrouping was 98.9%. Only two O157 isolates were misidentified as nontypeable and O121. The detection limits of all serotypes were distributed between 1.1 × 106 and 17.6 × 106 CFU/ml. Pulsed-field gel electrophoresis (PFGE) revealed the heterogeneity of the examined isolates. In conclusion, SPRi is a useful method for the O-antigen serogrouping of STEC isolates, but the further evaluation of non-O157 minor serogroups is needed.


Asunto(s)
Infecciones por Escherichia coli/diagnóstico , Antígenos O/inmunología , Escherichia coli Shiga-Toxigénica/clasificación , Escherichia coli Shiga-Toxigénica/inmunología , Resonancia por Plasmón de Superficie , Anticuerpos Antibacterianos/inmunología , Diagnóstico Precoz , Humanos , Límite de Detección , Serogrupo , Serotipificación , Toxina Shiga/análisis
12.
Artículo en Inglés | MEDLINE | ID: mdl-28630184

RESUMEN

Contamination of environmental waters by extended-spectrum-ß-lactamase (ESBL)-producing Escherichia coli (ESBLEC) is of great concern. Wastewater treatment plants (WWTPs) and hospitals release large amounts of ESBLEC into the environment. In the present study, we isolated ESBLEC strains from wastewater collected from a WWTP and a hospital in Japan and performed whole-genome sequencing to characterize these strains. Genomic analysis of 54 strains (32 from the WWTP and 22 from hospital wastewater) revealed the occurrence of clinically important clonal groups with extraintestinal pathogenic E. coli status in the WWTP and hospital wastewater. Fine-scale phylogenetic analysis was performed to further characterize 15 sequence type 131 (ST131) complex strains (11 from the WWTP and 4 from hospital wastewater). These ST131 complex strains were comprised of the following different subgroups: clade A (n = 2), C1-M27 (n = 8), and C1 (non-C1-M27) (n = 1) for strains from the WWTP and clade A (n = 2), C1-M27 (n = 1), and C1 (non-C1-M27) (n = 1) for strains from hospital wastewater. The results indicate that ESBLEC strains belonging to clinically important lineages, including the C1-M27 clade, may disseminate into the environment through wastewater, highlighting the need to monitor for antibiotic resistance in wastewater.


Asunto(s)
Escherichia coli/efectos de los fármacos , Escherichia coli/genética , Aguas Residuales/microbiología , Resistencia betalactámica/genética , beta-Lactamasas/genética , Escherichia coli/clasificación , Escherichia coli/metabolismo , Genoma Bacteriano/genética , Hospitales , Humanos , Pruebas de Sensibilidad Microbiana , Filogenia , Microbiología del Agua , beta-Lactamasas/biosíntesis
13.
Artículo en Inglés | MEDLINE | ID: mdl-28584160

RESUMEN

Escherichia coli sequence type 131 (ST131) is a pandemic clonal lineage that is responsible for the global increase in fluoroquinolone resistance and extended-spectrum-ß-lactamase (ESBL) producers. The members of ST131 clade C, especially subclades C2 and C1-M27, are associated with ESBLs. We developed a multiplex conventional PCR assay with the ability to detect all ST131 clades (A, B, and C), as well as C subclades (C1-M27, C1-nM27 [C1-non-M27], and C2). To validate the assay, we used 80 ST131 global isolates that had been fully sequenced. We then used the assay to define the prevalence of each clade in two Japanese collections consisting of 460 ESBL-producing E. coli ST131 (2001-12) and 329 E. coli isolates from extraintestinal sites (ExPEC) (2014). The assay correctly identified the different clades in all 80 global isolates: clades A (n = 12), B (n = 12), and C, including subclades C1-M27 (n = 16), C1-nM27 (n = 20), C2 (n = 17), and other C (n = 3). The assay also detected all 565 ST131 isolates in both collections without any false positives. Isolates from clades A (n = 54), B (n = 23), and C (n = 483) corresponded to the O serotypes and the fimH types of O16-H41, O25b-H22, and O25b-H30, respectively. Of the 483 clade C isolates, C1-M27 was the most common subclade (36%), followed by C1-nM27 (32%) and C2 (15%). The C1-M27 subclade with blaCTX-M-27 became especially prominent after 2009. Our novel multiplex PCR assay revealed the predominance of the C1-M27 subclade in recent Japanese ESBL-producing E. coli isolates and is a promising tool for epidemiological studies of ST131.


Asunto(s)
Antibacterianos/farmacología , Infecciones por Escherichia coli/microbiología , Escherichia coli/clasificación , Fluoroquinolonas/farmacología , beta-Lactamasas/genética , Escherichia coli/efectos de los fármacos , Escherichia coli/enzimología , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Humanos , Pruebas de Sensibilidad Microbiana , Filogenia , Secuenciación Completa del Genoma
14.
J Antimicrob Chemother ; 72(4): 1040-1049, 2017 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-28077674

RESUMEN

Objectives: To define the population structure of extraintestinal pathogenic Escherichia coli (ExPEC) in Japan and its relationship with antimicrobial resistance and the major resistance mechanisms for fluoroquinolones and ß-lactams, we designed a multicentre prospective study. Methods: A total of 329 ExPEC isolates were collected at 10 Japanese acute-care hospitals during December 2014. We defined the clonal groups of ExPEC by fumC and fimH sequencing (CH typing). Antimicrobial susceptibility testing of 18 agents and the detection of mutations in quinolone resistance-determining regions (QRDRs) and ß-lactamases were performed. Results: Among the study isolates, 103 CH types were found, and CH40-30 (25%) and another 10 CH types (35% in total) constituted the major ExPEC population. Ciprofloxacin non-susceptibility, ESBLs and MDR phenotypes were found in 34%, 22% and 33%, respectively. CH40-30, corresponding to the C/H30 clade of the global pandemic ST131 clone, was associated with four QRDR mutations (100%) and bla CTX-M (60%) and was the most frequent type in 15 antimicrobial-non-susceptible populations (dominating 39%-75% of each population, the highest prevalence for ciprofloxacin), the ESBL producers (70%) and the MDR isolates (59%). Isolates that were non-susceptible to nalidixic acid and low-level resistant to ciprofloxacin with one or two QRDR mutations represented 16% of the study isolates and were distributed among the eight major and non-major CH types. Conclusions: More than half of the ExPEC population in Japan consisted of 11 major clones. Of these clones, the CH40-30-ST131-C/H30 clone was the predominant antimicrobial-resistant population. The presence of major clones with low-level ciprofloxacin resistance supports the potential future success of a non-ST131 fluoroquinolone-resistant clone.


Asunto(s)
Farmacorresistencia Bacteriana , Infecciones por Escherichia coli/microbiología , Escherichia coli Patógena Extraintestinal/clasificación , Escherichia coli Patógena Extraintestinal/efectos de los fármacos , Variación Genética , Genotipo , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Antibacterianos/farmacología , Niño , Preescolar , Infecciones por Escherichia coli/epidemiología , Proteínas de Escherichia coli/genética , Escherichia coli Patógena Extraintestinal/genética , Escherichia coli Patógena Extraintestinal/aislamiento & purificación , Femenino , Hospitales , Humanos , Lactante , Recién Nacido , Japón/epidemiología , Masculino , Persona de Mediana Edad , Epidemiología Molecular , Tipificación Molecular , Estudios Prospectivos , Análisis de Secuencia de ADN , Adulto Joven
15.
Appl Environ Microbiol ; 83(5)2017 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-27986723

RESUMEN

Contamination of surface waters by antimicrobial-resistant bacteria and pathogenic bacteria is a great concern. In this study, 531 Escherichia coli isolates obtained from the Yamato River in Japan were evaluated phenotypically for resistance to 25 antimicrobials. Seventy-six isolates (14.3%) were multidrug resistant (MDR), 66 (12.4%) were nonsusceptible to one or two classes of agents, and 389 (73.3%) were susceptible. We performed whole-genome sequencing of selected strains by using Illumina technology. In total, the genome sequences of 155 strains were analyzed for antibiotic resistance determinants and phylogenetic characteristics. More than 50 different resistance determinants, including acquired resistance genes and chromosomal resistance mutations, were detected. Among the sequenced MDR strains (n = 66), sequence type 155 (ST155) complex (n = 9), ST10 complex (n = 9), and ST69 complex (n = 7) were prevalent. Among extraintestinal pathogenic E. coli (ExPEC) strains (n = 58), clinically important clonal groups, namely, ST95 complex (n = 18), ST127 complex (n = 8), ST12 complex (n = 6), ST14 complex (n = 6), and ST131 complex (n = 6), were prevalent, demonstrating the clonal distribution of environmental ExPEC strains. Typing of the fimH (type 1 fimbrial adhesin) gene revealed that ST131 complex strains carried fimH22 or fimH41, and no strains belonging to the fimH30 subgroup were detected. Fine-scale phylogenetic analysis and virulence gene content analysis of strains belonging to the ST95 complex (one of the major clonal ExPEC groups causing community-onset infections) revealed no significant differences between environmental and clinical strains. The results indicate contamination of surface waters by E. coli strains belonging to clinically important clonal groups.IMPORTANCE The prevalence of antimicrobial-resistant and pathogenic E. coli strains in surface waters is a concern because surface waters are used as sources for drinking water, irrigation, and recreational purposes. In this study, MDR and ExPEC strains in river water were characterized by genomic sequencing and analysis. We detected more than 50 resistance determinants and identified clonal groups specific to MDR and ExPEC strains. This study showed contamination of surface waters by E. coli strains belonging to clinically important clonal groups. Overall, this study advances our understanding of environmental MDR and ExPEC strains.


Asunto(s)
Farmacorresistencia Bacteriana Múltiple/genética , Microbiología Ambiental , Escherichia coli Patógena Extraintestinal/genética , Escherichia coli Patógena Extraintestinal/aislamiento & purificación , Genoma Bacteriano , Ríos/microbiología , Microbiología del Agua , Animales , Biodiversidad , ADN Bacteriano/genética , Infecciones por Escherichia coli/microbiología , Escherichia coli Patógena Extraintestinal/clasificación , Genes Bacterianos/genética , Genotipo , Humanos , Japón , Pruebas de Sensibilidad Microbiana , Tipificación Molecular , Mutación , Filogenia , Análisis de Secuencia de ADN , Virulencia/genética , Factores de Virulencia/genética , Contaminación del Agua
16.
Biochim Biophys Acta Proteins Proteom ; 1865(7): 828-836, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28341603

RESUMEN

Desmin-related cardiomyopathy is a heterogeneous group of myofibrillar myopathies characterized by aggregates of desmin and related proteins in myocytes. It has been debated how the expression and protein structure are altered in the aggregates and other parts of myocytes in patients. To address this question, we investigated the proteome quantification as well as localization in formalin-fixed and paraffin-embedded specimens of the heart of patients by imaging mass spectrometry and liquid chromatography-mass spectrometry analyses. Fifteen tryptic peptide signals were enriched in the desmin-related cardiomyopathy myocardium, twelve of which were identified as desmin peptides with 14.3- to 27.3-fold increase compared to normal hearts. High-intensity signals at m/z 1032.5 and 1002.5, which were desmin peptides 59-70 at the head portion and 213-222 at the 1B domain, were with infrequent colocalization distributed not only in desmin-positive intracytoplasmic aggregates but also in histologically normal cytoplasm, indicating that desmin protein is fragmented and different types of naturally-occurring truncated proteins ectopically assemble throughout the heart of patients. Thus, in addition to conventional histological identification of protein aggregates, specific desmin peptides show a marked difference in quantity and localization in a tissue section of desmin-related cardiomyopathy and differentiate from other cardiomyopathies. This article is part of a Special Issue entitled: MALDI Imaging, edited by Dr. Corinna Henkel and Prof. Peter Hoffmann.


Asunto(s)
Cardiomiopatías/metabolismo , Cardiomiopatías/patología , Citoplasma/metabolismo , Desmina/metabolismo , Miocardio/metabolismo , Péptidos/metabolismo , Agregado de Proteínas/fisiología , Adulto , Cromatografía Liquida/métodos , Femenino , Humanos , Filamentos Intermedios/metabolismo , Masculino , Persona de Mediana Edad , Células Musculares/metabolismo , Células Musculares/patología , Enfermedades Musculares/metabolismo , Enfermedades Musculares/patología , Miocardio/patología , Proteoma/metabolismo , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Adulto Joven
17.
Anaerobe ; 48: 215-223, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28935196

RESUMEN

This prospective multicenter surveillance study was designed to provide antimicrobial susceptibility profiles of clinical anaerobic bacteria with genetic species identification in Japan. In 2014, a total of 526 non-duplicate clinical anaerobic isolates were collected from 11 acute-care hospitals in the Kyoto and Shiga regions of Japan. Genetic identification was performed using 16S rRNA sequencing. Minimum inhibitory concentrations were determined in the central laboratory and were interpreted using the CLSI criteria. Genetic analysis provided species-level identification for 496 isolates (83 species in 40 genera) and genus-level identification for 21 isolates (13 genera). Among these 517 isolates, the most frequent anaerobes were Bacteroides spp. (n = 207), Prevotella spp. (n = 43), Clostridium spp. (n = 40), and Peptoniphilus spp. (n = 40). B. fragilis was the most common species (n = 107) and showed 91.6%-97.2% susceptibility to ß-lactam/ß-lactamase inhibitor combinations (BLBLIs; ampicillin-sulbactam, amoxicillin-clavulanate, and piperacillin-tazobactam) and carbapenems (imipenem and meropenem) as well as 100% susceptibility to metronidazole. Gram-negative anaerobes were highly susceptible to metronidazole (99.0%) followed by BLBLIs and carbapenems (>90% each). BLBLIs or carbapenems also retained activity against Gram-positive anaerobes (99.5%-100%) except Clostridioides difficile. All isolates were susceptible to combinations of metronidazole with BLBLIs or carbapenems. Thus, BLBLIs or carbapenems are first choices for empirical therapy of anaerobic infections in Japan, and these antimicrobials in combination with metronidazole should be reserved for very severe infections and targeted therapy.


Asunto(s)
Antibacterianos/farmacología , Bacterias Anaerobias/efectos de los fármacos , Bacterias Anaerobias/genética , Infecciones Bacterianas/epidemiología , Infecciones Bacterianas/microbiología , Vigilancia en Salud Pública , Bacterias Anaerobias/clasificación , Bacterias Anaerobias/aislamiento & purificación , Femenino , Humanos , Japón/epidemiología , Masculino , Pruebas de Sensibilidad Microbiana , ARN Ribosómico 16S
18.
Emerg Infect Dis ; 22(11): 1900-1907, 2016 11.
Artículo en Inglés | MEDLINE | ID: mdl-27767006

RESUMEN

The Escherichia coli sequence type (ST) 131 C2/H30Rx clade with the blaCTX-M-15 gene had been most responsible for the global dissemination of extended-spectrum ß-lactamase (ESBL)-producing E. coli. ST131 C1/H30R with blaCTX-M-27 emerged among ESBL-producing E. coli in Japan during the late 2000s. To investigate the possible expansion of a single clade, we performed whole-genome sequencing for 43 Japan and 10 global ST131 isolates with blaCTX-M-27 (n = 16), blaCTX-M-14 (n = 16), blaCTX-M-15 (n = 13), and others (n = 8). We also included 8 ST131 genomes available in public databases. Core genome-based analysis of 61 isolates showed that ST131 with blaCTX-M-27 from 5 countries formed a distinct cluster within the C1/H30R clade, named C1-M27 clade. Accessory genome analysis identified a unique prophage-like region, supporting C1-M27 as a distinct clade. Our findings indicate that the increase of ESBL-producing E. coli in Japan is due mainly to emergence of the C1-M27 clade.


Asunto(s)
Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/microbiología , Proteínas de Escherichia coli/genética , Escherichia coli/clasificación , Escherichia coli/genética , Genotipo , beta-Lactamasas/genética , Salud Global , Humanos
19.
Antimicrob Agents Chemother ; 60(9): 5412-9, 2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-27381397

RESUMEN

Carbapenemase-producing Gram-negative bacilli have been a global concern over the past 2 decades because these organisms can cause severe infections with high mortality rates. Carbapenemase genes are often carried by mobile genetic elements, and resistance plasmids can be transferred through conjugation. We conducted whole-genome sequencing (WGS) to demonstrate that the same plasmid harboring a metallo-ß-lactamase gene was detected in two different species isolated from a single patient. Metallo-ß-lactamase-producing Achromobacter xylosoxidans (KUN4507), non-metallo-ß-lactamase-producing Klebsiella pneumoniae (KUN4843), and metallo-ß-lactamase-producing K. pneumoniae (KUN5033) were sequentially isolated from a single patient and then analyzed in this study. Antimicrobial susceptibility testing, molecular typing (pulsed-field gel electrophoresis and multilocus sequence typing), and conjugation analyses were performed by conventional methods. Phylogenetic and molecular clock analysis of K. pneumoniae isolates were performed with WGS, and the nucleotide sequences of plasmids detected from these isolates were determined using WGS. Conventional molecular typing revealed that KUN4843 and KUN5033 were identical, whereas the phylogenetic tree analysis revealed a slight difference. These two isolates were separated from the most recent common ancestor 0.74 years before they were isolated. The same resistance plasmid harboring blaIMP-19 was detected in metallo-ß-lactamase-producing A. xylosoxidans and K. pneumoniae Although this plasmid was not self-transferable, the conjugation of this plasmid from A. xylosoxidans to non-metallo-ß-lactamase-producing K. pneumoniae was successfully performed. The susceptibility patterns for metallo-ß-lactamase-producing K. pneumoniae and the transconjugant were similar. These findings supported the possibility of the horizontal transfer of plasmid-borne blaIMP-19 from A. xylosoxidans to K. pneumoniae in a single patient.


Asunto(s)
Achromobacter denitrificans/genética , Transferencia de Gen Horizontal , Genoma Bacteriano , Klebsiella pneumoniae/genética , Plásmidos/química , beta-Lactamasas/genética , Achromobacter denitrificans/metabolismo , Antibacterianos/farmacología , Conjugación Genética , Farmacorresistencia Bacteriana Múltiple , Electroforesis en Gel de Campo Pulsado , Expresión Génica , Humanos , Klebsiella pneumoniae/metabolismo , Masculino , Persona de Mediana Edad , Tipificación de Secuencias Multilocus , Filogenia , Plásmidos/clasificación , Plásmidos/metabolismo , beta-Lactamasas/metabolismo
20.
Cereb Cortex ; 25(11): 4535-50, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25962920

RESUMEN

Previous neurophysiological studies performed in macaque monkeys have shown that the secondary somatosensory cortex (SII) is essentially engaged in the processing of somatosensory information and no other sensory input has been reported. In contrast, recent human brain-imaging studies have revealed the effects of visual and auditory stimuli on SII activity, which suggest multisensory integration in the human SII. To determine whether multisensory responses of the SII also exist in nonhuman primates, we recorded single-unit activity in response to visual and auditory stimuli from the SII and surrounding regions in 8 hemispheres from 6 awake monkeys. Among 1157 recorded neurons, 306 neurons responded to visual stimuli. These visual neurons usually responded to rather complex stimuli, such as stimulation of the peripersonal space (40.5%), observation of human action (29.1%), and moving-object stimulation outside the monkey's reach (23.9%). We occasionally applied auditory stimuli to visual neurons and found 10 auditory-responsive neurons that exhibited somatosensory responses. The visual neurons were distributed continuously along the lateral sulcus covering the entire SII, along with other somatosensory neurons. These results highlight the need to investigate novel functional roles-other than somesthetic sensory processing-of the SII.


Asunto(s)
Potenciales de Acción/fisiología , Red Nerviosa/fisiología , Neuronas/fisiología , Corteza Somatosensorial/citología , Vigilia/fisiología , Estimulación Acústica , Animales , Femenino , Miembro Anterior/fisiología , Lateralidad Funcional , Humanos , Macaca fascicularis , Masculino , Percepción de Movimiento/fisiología , Neuronas/clasificación , Estimulación Luminosa , Desempeño Psicomotor/fisiología
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