scholarly journals Prevalence and Molecular Characterization of mcr-1-Positive Salmonella Strains Recovered from Clinical Specimens in China

2017 ◽  
Vol 61 (5) ◽  
Author(s):  
Mingquan Cui ◽  
Jinfei Zhang ◽  
Zhen Gu ◽  
Ruichao Li ◽  
Edward Wai-chi Chan ◽  
...  
Keyword(s):  
Pulsed Field Gel Electrophoresis ◽  
Clinical Settings ◽  
Colistin Resistance ◽  
Content Type ◽  
Transmission Potential ◽  
Conjugative Plasmids ◽  
Plasmid Analysis ◽  
Antimicrobial Resistance Genes ◽  
Pfge Profiles

ABSTRACT The recently discovered colistin resistance element, mcr-1, adds to the list of antimicrobial resistance genes that rapidly erode the antimicrobial efficacy of not only the commonly used antibiotics but also the last-line agents of carbapenems and colistin. This study investigated the prevalence of the mobile colistin resistance determinant mcr-1 in Salmonella strains recovered from clinical settings in China and the transmission potential of mcr-1-bearing mobile elements harbored by such isolates. The mcr-1 gene was recoverable in 1.4% of clinical isolates tested, with the majority of them belonging to Salmonella enterica serotype Typhimurium. These isolates exhibited diverse pulsed-field gel electrophoresis (PFGE) profiles and high resistance to antibiotics other than colistin and particularly to cephalosporins. Plasmid analysis showed that mcr-1 was carried on a variety of plasmids with sizes ranging from ∼30 to ∼250 kb, among which there were conjugative plasmids of ∼30 kb, ∼60 kb, and ∼250 kb and nonconjugative plasmids of ∼140 kb, ∼180 kb, and ∼240 kb. Sequencing of representative mcr-1-carrying plasmids revealed that all conjugative plasmids belonged to the IncX4, IncI2, and IncHI2 types and were highly similar to the corresponding types of plasmids reported previously. Nonconjugative plasmids all belonged to the IncHI2 type, and the nontransferability of these plasmids was attributed to the loss of a region carrying partial or complete tra genes. Our data revealed that, similar to the situation in Escherichia coli, mcr-1 transmission in Salmonella was accelerated by various plasmids, suggesting that transmission of mcr-1-carrying plasmids between different species of Enterobacteriaceae may be a common event.

scholarly journals Conjugal Transfer, Whole-Genome Sequencing, and Plasmid Analysis of Four mcr-1-Bearing Isolates from U.S. Patients

2019 ◽  
Vol 63 (4) ◽  
Author(s):  
Wenming Zhu ◽  
Adrian Lawsin ◽  
Rebecca L. Lindsey ◽  
Dhwani Batra ◽  
Kristen Knipe ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Genome Sequencing ◽  
Resistance Genes ◽  
Whole Genome ◽  
Colistin Resistance ◽  
Content Type ◽  
Plasmid Analysis ◽  
Antimicrobial Resistance Genes

ABSTRACT Four Enterobacteriaceae clinical isolates bearing mcr-1 gene-harboring plasmids were characterized. All isolates demonstrated the ability to transfer colistin resistance to Escherichia coli; plasmids were stable in conjugants after multiple passages on nonselective media. mcr-1 was located on an IncX4 (n = 3) or IncN (n = 1) plasmid. The IncN plasmid harbored 13 additional antimicrobial resistance genes. Results indicate that the mcr-1-bearing plasmids in this study were highly transferable in vitro and stable in the recipients.

scholarly journals In Vitro Isolation and Characterization of Oxazolidinone-Resistant Mycobacterium tuberculosis

2017 ◽  
Vol 61 (10) ◽  
Author(s):  
Matthew B. McNeil ◽  
Devon D. Dennison ◽  
Catherine D. Shelton ◽  
Tanya Parish
Keyword(s):  
Mycobacterium Tuberculosis ◽  
23S Rrna ◽  
Clinical Settings ◽  
Content Type ◽  
Isolation And Characterization ◽  
Mutant Strains ◽  
Ribosomal Protein L3 ◽  
Resistant Strains

ABSTRACT Oxazolidinones are promising candidates for the treatment of Mycobacterium tuberculosis infections. We isolated linezolid-resistant strains from H37Rv (Euro-American) and HN878 (East-Asian) strains; resistance frequencies were similar in the two strains. Mutations were identified in ribosomal protein L3 (RplC) and the 23S rRNA (rrl). All mutant strains were cross resistant to sutezolid; a subset was cross resistant to chloramphenicol. Mutations in rrl led to growth impairment and decreased fitness that may limit spread in clinical settings.

scholarly journals Pulsed-Field Gel Electrophoresis and PCR Characterization of Environmental Vibrio parahaemolyticus Strains of Different Origins

2011 ◽  
Vol 77 (17) ◽  
pp. 6301-6304 ◽  
Author(s):  
E. Suffredini ◽  
C. Lopez-Joven ◽  
L. Maddalena ◽  
L. Croci ◽  
A. Roque
Keyword(s):  
Gel Electrophoresis ◽  
Vibrio Parahaemolyticus ◽  
Genetic Relationships ◽  
Pulsed Field Gel Electrophoresis ◽  
Environmental Isolates ◽  
Content Type ◽  
Pulsed Field ◽  
Intraspecies Variability ◽  
Different Origins

ABSTRACTThe present study used pulsed-field gel electrophoresis (PFGE) characterization to examine the intraspecies variability and genetic relationships among environmental isolates ofVibrio parahaemolyticusfrom different European countries. This is first study performed on environmentalV. parahaemolyticusthat included more than one European country.

scholarly journals Characterization of Extended-Spectrum β-Lactamase-Producing Salmonella typhimurium by Phenotypic and Genotypic Typing Methods

1999 ◽  
Vol 37 (11) ◽  
pp. 3769-3773 ◽  
Author(s):  
Rajaa Ait Mhand ◽  
Naima Brahimi ◽  
Najat Moustaoui ◽  
Naima El Mdaghri ◽  
Hamid Amarouch ◽  
...  
Keyword(s):  
Salmonella Typhimurium ◽  
Pulsed Field Gel Electrophoresis ◽  
Randomly Amplified Polymorphic Dna ◽  
Antibiotic Susceptibility Pattern ◽  
Extended Spectrum ◽  
Plasmid Analysis ◽  
Rapd Pattern ◽  
Typing Methods ◽  
Pattern Determination

During 1994, 10 isolates of extended-spectrum β-lactamase-producing Salmonella typhimurium were recovered from children transferred to our hospital from two different centers. Two additional isolates were recovered from two nurses from one of these centers. The aim of this study was to determine if there is any relationship between these isolates. The characterization was done by phenotypic and genotypic methods: biotyping, phage typing, antibiotic susceptibility pattern determination, plasmid analysis, ribotyping (by the four endonucleases EcoRI,SmaI, BglII, and PvuII), pulsed-field gel electrophoresis (PFGE) of genome macrorestriction patterns with XbaI, and randomly amplified polymorphic DNA (RAPD) pattern determination (with the three primers 217 d2, B1, and A3). The same biotype, the same serotype, and an identical antibiotype were found. All isolates were resistant to oxyimino-β-lactams, gentamicin, tobramycin, and sulfamethoxazole-trimethoprim. All isolates showed an indistinguishable pattern by ribotyping and very similar patterns by PFGE and RAPD. The overall results indicated the spread of a closely related strain of S. typhimurium in children and nurses.

scholarly journals Molecular Characterization of IMP-1-Producing Enterobacter cloacae Complex Isolates in Tokyo

2018 ◽  
Vol 62 (3) ◽  
Author(s):  
Kotaro Aoki ◽  
Sohei Harada ◽  
Koji Yahara ◽  
Yoshikazu Ishii ◽  
Daisuke Motooka ◽  
...  
Keyword(s):  
Enterobacter Cloacae ◽  
Asia Pacific ◽  
Single Nucleotide ◽  
Content Type ◽  
Plasmid Analysis ◽  
Enterobacter Hormaechei ◽  
Clade 1 ◽  
Genetic Structures ◽  
Sequence Types

ABSTRACT Although KPC enzymes are most common among carbapenemases produced by Enterobacter cloacae complex globally, the epidemiology varies from one country to another. While previous studies have suggested that IMP enzymes are most common in Japan, detailed analysis has been scarce thus far. Here, we carried out a molecular epidemiological study and plasmid analysis of IMP-1-producing E. cloacae complex isolates collected from three hospitals in central Tokyo using whole-genome sequencing. Seventy-one isolates were classified into several sequence types (STs), and 49 isolates were identified as Enterobacter hormaechei ST78. Isolates of ST78 were divided into three clades by core-genome single nucleotide polymorphism (SNP)-based phylogenetic analysis. Whereas isolates of clade 3 were isolated from only one hospital, isolates of clade 1 and 2 were identified from multiple hospitals. Ten of 12 clade 1 isolates and 1 of 4 clade 2 isolates carried bla IMP-1 on IncHI2 plasmids, with high similarity of genetic structures. In addition, these plasmids shared backbone structures with IncHI2 plasmids carrying bla IMP reported from other countries of the Asia-Pacific region. All isolates of clade 3 except one carried bla IMP-1 in In1426 on IncW plasmids. An isolate of clade 3, which lacked IncW plasmids, carried bla IMP-1 in In1426 on an IncFIB plasmid. These observations suggest that IMP-producing E. cloacae complex isolates with a diversity of host genomic backgrounds have spread in central Tokyo, and they indicate the possible contribution of IncHI2 plasmids toward this phenomenon.

scholarly journals Whole-Genome Sequences of Two Listeria monocytogenes Serovar 1/2a Strains Responsible for a Severe Listeriosis Outbreak in Central Italy

2018 ◽  
Vol 6 (24) ◽  
Author(s):  
Massimiliano Orsini ◽  
Alessandra Cornacchia ◽  
Claudio Patavino ◽  
Marina Torresi ◽  
Patrizia Centorame ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Gel Electrophoresis ◽  
Central Italy ◽  
Pulsed Field Gel Electrophoresis ◽  
Single Band ◽  
Whole Genome ◽  
Genome Sequences ◽  
Content Type ◽  
Pulsed Field ◽  
Pfge Profiles

ABSTRACT We report the whole-genome sequences of two Listeria monocytogenes strains responsible for a severe invasive listeriosis outbreak in central Italy that occurred in 2015 and 2016. These two strains differ by a single band in their pulsed-field gel electrophoresis (PFGE) profiles.

scholarly journals Study ofStaphylococcus aureuscollected at slaughter from dairy cows with chronic mastitis

2012 ◽  
Vol 79 (2) ◽  
pp. 249-255 ◽  
Author(s):  
Renata Piccinini ◽  
Riccardo Tassi ◽  
Valentina Daprà ◽  
Rachel Pilla ◽  
Jackie Fenner ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Gel Electrophoresis ◽  
Bovine Mastitis ◽  
Pulsed Field Gel Electrophoresis ◽  
Mammary Tissue ◽  
Molecular Characteristics ◽  
Dairy Herds ◽  
Staph Aureus ◽  
Pfge Profiles

Staphylococcus aureusis one of the most important pathogens associated with bovine mastitis. Recent studies have shown thatStaph. aureusstrains may differ in virulence, and in their ability to disseminate across commercial dairy herds. The goal of this study was to determine whetherStaph. aureusisolates differed in their ability to colonize mammary tissue, and whether such differences could be related to molecular characteristics. Quarter milk and mammary tissues of 22 cows from two dairy herds, were collected at slaughter and bacteriological analysis was performed. AllStaph. aureusisolates were characterized by Pulsed Field Gel Electrophoresis (PFGE) and microarray. Overall 45 mammary quarters were infected and 20Staph. aureusisolates were identified. The bacteria were mostly recovered from both milk and tissue of the same quarter in significantly higher numbers from herd A cows compared with herd B. Molecular characterization of the isolates showed distinct PFGE profiles for isolates from each herd. Differences in virulence factors between herds A and B isolates were evidenced The genes for enterotoxin D, J and R were present in herd A, those for G, I, N, M, O and U were shown in herd B, whilst both components of the leukocidinlukD/Egenes were only carried by herd A isolates. Furthermore, all herd A isolates showed β-haemolysin activity, which was absent in all but one isolate from herd B. Therefore our data indicate thatStaph. aureusisolates showing differences in their ability to disseminate and colonize across quarters, also have significantly different virulence characteristics.

scholarly journals Detection of Five mcr-9-Carrying Enterobacterales Isolates in Four Czech Hospitals

mSphere ◽  
2020 ◽  
Vol 5 (6) ◽  
Author(s):  
Ibrahim Bitar ◽  
Costas C. Papagiannitsis ◽  
Lucie Kraftova ◽  
Katerina Chudejova ◽  
Vittoria Mattioni Marchetti ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Resistance Mechanisms ◽  
Mobile Elements ◽  
Citrobacter Freundii ◽  
Colistin Resistance ◽  
Content Type ◽  
Resistance Determinants ◽  
Enterobacter Hormaechei ◽  
First Time

ABSTRACT The aim of this study was to report the characterization of the first mcr-positive Enterobacterales isolated from Czech hospitals. In 2019, one Citrobacter freundii and four Enterobacter isolates were recovered from Czech hospitals. The production of carbapenemases was examined by a matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) imipenem hydrolysis assay. Additionally, bacteria were screened for the presence of carbapenemase-encoding genes and plasmid-mediated colistin resistance genes by PCR. To define the genetic units carrying mcr genes, the genomic DNAs of mcr-carrying clinical isolates were sequenced on the PacBio Sequel I platform. Results showed that all isolates carried blaVIM- and mcr-like genes. Analysis of whole-genome sequencing (WGS) data revealed that all isolates carried mcr-9-like alleles. Furthermore, the three sequence type 106 (ST106) Enterobacter hormaechei isolates harbored the blaVIM-1 gene, while the ST764 E. hormaechei and ST95 C. freundii included blaVIM-4. Analysis of plasmid sequences showed that, in all isolates, mcr-9 was carried on IncHI2 plasmids. Additionally, at least one multidrug resistance (MDR) region was identified in each mcr-9-carrying IncHI2 plasmid. The blaVIM-4 gene was found in the MDR regions of p48880_MCR_VIM and p51929_MCR_VIM. In the three remaining isolates, blaVIM-1 was localized on plasmids (∼55 kb) exhibiting repA-like sequences 99% identical to the respective gene of pKPC-CAV1193. In conclusion, to the best of our knowledge, these 5 isolates were the first mcr-9-positive bacteria of clinical origin identified in the Czech Republic. Additionally, the carriage of the blaVIM-1 on pKPC-CAV1193-like plasmids is described for the first time. Thus, our findings underline the ongoing evolution of mobile elements implicated in the dissemination of clinically important resistance determinants. IMPORTANCE Infections caused by carbapenemase-producing bacteria have led to the revival of polymyxins as the “last-resort” antibiotic. Since 2016, several reports describing the presence of plasmid-mediated colistin resistance genes, mcr, in different host species and geographic areas were published. Here, we report the first detection of Enterobacterales carrying mcr-9-like alleles isolated from Czech hospitals in 2019. Furthermore, the three ST106 Enterobacter hormaechei isolates harbored blaVIM-1, while the ST764 E. hormaechei and ST95 Citrobacter freundii isolates included blaVIM-4. Analysis of WGS data showed that, in all isolates, mcr-9 was carried on IncHI2 plasmids. blaVIM-4 was found in the MDR regions of IncHI2 plasmids, while blaVIM-1 was localized on pKPC-CAV1193-like plasmids, described here for the first time. These findings underline the ongoing evolution of mobile elements implicated in dissemination of clinically important resistance determinants. Thus, WGS characterization of MDR bacteria is crucial to unravel the mechanisms involved in dissemination of resistance mechanisms.

scholarly journals Characterization of the Complete Nucleotide Sequences of IMP-4-Encoding Plasmids, Belonging to Diverse Inc Families, Recovered from Enterobacteriaceae Isolates of Wildlife Origin

2018 ◽  
Vol 62 (5) ◽  
Author(s):  
Monika Dolejska ◽  
Costas C. Papagiannitsis ◽  
Matej Medvecky ◽  
Lenka Davidova-Gerzova ◽  
Adam Valcek
Keyword(s):  
Nucleotide Sequences ◽  
Sequencing Data ◽  
Content Type ◽  
Plasmid Analysis

ABSTRACT The complete nucleotide sequences of six IMP-4-encoding plasmids recovered from Enterobacteriaceae isolates of wildlife origin were characterized. Sequencing data showed that plasmids of different incompatibility groups (IncM, IncI1, IncF, and nontypeable [including an IncX5_2 and two pPrY2001-like]) carried the bla IMP-4 -carrying integrons In809 or In1460. Most of the plasmids carried an mph (A) region, and chrA -like, aac(3)-IId , and bla TEM-1b genes. Finally, plasmid analysis revealed the involvement of two different IS 26 - and Tn 1696 -associated mechanisms in the mobilization of IMP-4-encoding integrons.

scholarly journals Emergence of OXA-48-Type Carbapenemase-Producing Enterobacteriaceae in German Hospitals

2012 ◽  
Vol 56 (4) ◽  
pp. 2125-2128 ◽  
Author(s):  
Yvonne Pfeifer ◽  
Kathrin Schlatterer ◽  
Elisabeth Engelmann ◽  
Reinhold A. Schiller ◽  
Hans Reiner Frangenberg ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Gel Electrophoresis ◽  
Insertion Sequence ◽  
Pulsed Field Gel Electrophoresis ◽  
Mutant Form ◽  
Content Type ◽  
Point Mutant ◽  
Pulsed Field ◽  
Conjugative Plasmids ◽  
Carbapenem Resistant

ABSTRACTNine carbapenem-resistantEnterobacteriaceaeisolates collected from eight patients in five German hospitals were investigated. Six isolates produced the OXA-48 carbapenemase, and three isolates produced OXA-162, which is a point mutant form of OXA-48. Both carbapenemase genes were located on IncL/M-type conjugative plasmids. Insertion sequence IS1999(truncated or not by IS1R) was located upstream of theblaOXA-48andblaOXA-162genes in all of the isolates. Pulsed-field gel electrophoresis typing indicated the clonal transmission of an OXA-48-producingKlebsiella pneumoniaestrain in two hospitals.

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