scholarly journals Characterization of sulphonamide-resistant Escherichia coli using comparison of sul2 gene sequences and multilocus sequence typing

Microbiology ◽  
2009 ◽  
Vol 155 (3) ◽  
pp. 831-836 ◽  
Author(s):  
Margarita Trobos ◽  
Henrik Christensen ◽  
Marianne Sunde ◽  
Steen Nordentoft ◽  
Yvonne Agersø ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Multilocus Sequence Typing ◽  
Point Mutations ◽  
Bloodstream Infections ◽  
Poultry Meat ◽  
E Coli ◽  
Pcr Products ◽  
Synonymous Change ◽  
Host Origin

The sul2 gene encodes sulphonamide resistance (SulR) and is commonly found in Escherichia coli from different hosts. We typed E. coli isolates by multilocus sequence typing (MLST) and compared the results to sequence variation of sul2, in order to investigate the relation to host origin of pathogenic and commensal E. coli strains and to investigate whether transfer of sul2 into different genomic lineages has happened multiple times. Sixty-eight E. coli isolated in Denmark and Norway from different hosts and years were MLST typed and sul2 PCR products were sequenced and compared. PFGE was performed in a subset of isolates. All isolates were divided into 45 different sequence types (STs), with clonal complexes CC10, CC23, CC168, CC350 and CC69 being the most frequent. The sul2 gene from the majority of E. coli strains had only two point mutations, at positions 159 and 197, leading to a synonymous and a non-synonymous change, respectively. Five strains had extra single mutations. All poultry, poultry meat, and Danish human blood isolates had the same sul2 ST and some of these strains clustered under the same MLST STs, indicating that they shared habitats. Most PFGE profiles clustered according to source, but some included different sources. SulR E. coli from different animals, food, human faeces and infections did not cluster according to their origin, suggesting that these habitats share E. coli and sul2 gene types. However, while pig isolates on one occasion clustered with urinary tract infection isolates, poultry isolates seemed more related to isolates from bloodstream infections in humans. Presence of mainly two types of the sul2 gene in both human and animal isolates, irrespective of date and geography, and the presence of both types in the same clonal lineages, suggest horizontal transfer of sul2.

Characteristics of Extended-Spectrum Cephalosporin-Resistant Escherichia coli Isolated from Swiss and Imported Poultry Meat

2014 ◽  
Vol 77 (1) ◽  
pp. 112-112 ◽  
Author(s):  
H. ABGOTTSPON ◽  
R. STEPHAN ◽  
C. BAGUTTI ◽  
P. BRODMANN ◽  
H. HÄCHLER ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Multilocus Sequence Typing ◽  
Multidrug Resistant ◽  
Poultry Meat ◽  
Phylogenetic Groups ◽  
E Coli ◽  
Plasmid Incompatibility ◽  
Extended Spectrum ◽  
Resistance Patterns

A worrisome phenomenon is the progressive global spread of Enterobacteriaceae in poultry and chicken meat expressing plasmid-mediated enzymes that inactivate β-lactam antibiotics, suggesting that the food chain might play a role in the epidemiology and the transmission of extended-spectrum cephalosporin-resistant Enterobacteriaceae to humans. The aim of the present study was to further characterize 24 extended-spectrum cephalosporin-resistant Enterobacteriaceae isolated from domestic and imported poultry meat by antibiotic susceptibility testing, identification of the blaESBL/blapAmpC genes, conjugation mating experiments and determination of plasmid incompatibility types, multilocus sequence typing, and analysis of the Escherichia coli phylogenetic groups. On account of their resistance patterns, 21 of the total 24 isolates were classified as multidrug resistant. Eleven isolates carried a blaCMY-2 gene, whereas 13 isolates harbored a blaCTX-M-1 gene. All isolates harbored plasmids that were assigned to 8 of the 18 described plasmid incompatibility groups, the most frequent of which were IncI1, IncFIB, IncB/O, and IncFrepB. The blaESBL/blapAmpC genes were harbored mainly by transferable IncI1 and IncB/O plasmids. Multilocus sequence typing as well as E. coli phylogenetic group typing revealed a high heterogenicity even among different isolates of the same sample.

scholarly journals Detection and Characterization of Shiga ToxigenicEscherichia coli by Using Multiplex PCR Assays forstx 1, stx 2,eaeA, Enterohemorrhagic E. coli hlyA,rfb O111, andrfb O157

1998 ◽  
Vol 36 (2) ◽  
pp. 598-602 ◽  
Author(s):  
Adrienne W. Paton ◽  
James C. Paton
Keyword(s):  
Escherichia Coli ◽  
Multiplex Pcr ◽  
Genetic Characterization ◽  
Gastrointestinal Disease ◽  
Diverse Group ◽  
E Coli ◽  
Pcr Products ◽  
Uremic Syndrome ◽  
Pcr Assays

Shiga toxigenic Escherichia coli (STEC) comprises a diverse group of organisms capable of causing severe gastrointestinal disease in humans. Within the STEC family, certain strains appear to be of greater virulence for humans, for example, those belonging to serogroups O111 and O157 and those with particular combinations of other putative virulence traits. We have developed two multiplex PCR assays for the detection and genetic characterization of STEC in cultures of feces or foodstuffs. Assay 1 utilizes four PCR primer pairs and detects the presence of stx 1,stx 2 (including variants ofstx 2), eaeA, and enterohemorrhagicE. coli hlyA, generating amplification products of 180, 255, 384, and 534 bp, respectively. Assay 2 uses two primer pairs specific for portions of the rfb (O-antigen-encoding) regions of E. coli serotypes O157 and O111, generating PCR products of 259 and 406 bp, respectively. The two assays were validated by testing 52 previously characterized STEC strains and observing 100% agreement with previous results. Moreover, assay 2 did not give a false-positive O157 reaction with enteropathogenic E. colistrains belonging to clonally related serogroup O55. Assays 1 and 2 detected STEC of the appropriate genotype in primary fecal cultures from five patients with hemolytic-uremic syndrome and three with bloody diarrhea. Thirty-one other primary fecal cultures from patients without evidence of STEC infection were negative.

scholarly journals Sequential acquisition of virulence and fluoroquinolone resistance has shaped the evolution of Escherichia coli ST131

2016 ◽  
Author(s):  
Nouri L Ben Zakour ◽  
Areej S Alsheikh-Hussain ◽  
Melinda M Ashcroft ◽  
Nguyen Thi Khanh Nhu ◽  
Leah W Roberts ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Point Mutations ◽  
Population Expansion ◽  
Bloodstream Infections ◽  
Fluoroquinolone Resistance ◽  
E Coli ◽  
Genomic Epidemiology ◽  
Epidemiology Studies ◽  
The Impact ◽  
Different Sources

Escherichia coli ST131 is the most frequently isolated fluoroquinolone resistant (FQR) E. coli clone worldwide and a major cause of urinary tract and bloodstream infections. Although originally identified through its association with the CTX-M-15 extended-spectrum β-lactamase resistance gene, global genomic epidemiology studies have failed to resolve the geographical and temporal origin of the ST131 ancestor. Here, we developed a framework for the reanalysis of publicly available genomes from different sources and used this dataset to reconstruct the evolutionary steps that led to the emergence of FQR ST131. Using Bayesian estimation, we show that point mutations in chromosomal genes that confer FQR coincide with the first clinical use of fluoroquinolone in 1986, and illustrate the impact of this pivotal event in the rapid population expansion of ST131 worldwide from an apparent origin in North America. Furthermore, we identify key virulence factor acquisition events that predate the development of FQR, suggesting that the gain of virulence-associated genes followed by the tandem development of antibiotic resistance primed the successful global dissemination of ST131.

Phenotypic and genotypic quinolone resistance in Escherichia coli underlining GyrA83/87 mutations as a target to detect ciprofloxacin resistance

2020 ◽  
Vol 75 (9) ◽  
pp. 2466-2470
Author(s):  
Anaëlle Muggeo ◽  
Emmanuelle Cambau ◽  
Marlène Amara ◽  
Maïté Micaëlo ◽  
Béatrice Pangon ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Efflux Pump ◽  
Bloodstream Infections ◽  
Blood Cultures ◽  
Quinolone Resistance ◽  
E Coli ◽  
Molecular Determinants ◽  
Ciprofloxacin Resistance ◽  
First Time

Abstract Background Quinolone resistance (QR) is one component of the MDR emerging in Escherichia coli and is of particular concern given the widespread use of fluoroquinolones. Objectives To characterize the QR phenotypes and genotypes in E. coli responsible for bloodstream infections and to propose molecular determinants that could be targeted to predict ciprofloxacin resistance. Methods E. coli isolates from blood cultures in three French hospitals were studied for quinolone MICs and characterization of genotypic QR determinants (QRg). Results Among 507 isolates tested for MICs, 148 (29.2%) were resistant to quinolones based on EUCAST breakpoints and 143 (28.2%) harboured at least one QRg. QRg were mainly mutations in the QRDR (138 isolates, 27.2%), with 55.8% of these isolates carrying at least three QRDR mutations. gyrA mutations predominated (92.8%) followed by parC (61.6%), parE (32.6%) and gyrB (1.4%) mutations. Only 4.7% of the isolates harboured a plasmid-mediated quinolone resistance (PMQR) gene: aac(6′)-Ib-cr (60.0%) or qnr (qnrS, qnrB) (32.0%). For the first time in France, we reported the qepA4 allele of the plasmid-encoded efflux pump QepA. Only five isolates carried PMQR without a QRDR mutation. The positive predictive value (PPV) for ciprofloxacin resistance was 100% for any QRg and 99.2% for gyrA mutations specifically. Conclusions QR observed in E. coli isolates involved in bloodstream infections is still mainly due to QRDR mutations, especially at codons GyrA83/87, which could be used as a molecular target to rapidly detect resistance.

scholarly journals Host-Specific Patterns of Genetic Diversity among IncI1-Iγ and IncK Plasmids Encoding CMY-2 β-Lactamase in Escherichia coli Isolates from Humans, Poultry Meat, Poultry, and Dogs in Denmark

2016 ◽  
Vol 82 (15) ◽  
pp. 4705-4714 ◽  
Author(s):  
Katrine Hartung Hansen ◽  
Valeria Bortolaia ◽  
Christine Ahl Nielsen ◽  
Jesper Boye Nielsen ◽  
Kristian Schønning ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Host Species ◽  
Multilocus Sequence Typing ◽  
Human Exposure ◽  
Resistance Determinant ◽  
Poultry Meat ◽  
Animal Origin ◽  
Nucleotide Polymorphisms ◽  
Content Type ◽  
E Coli

ABSTRACTCMY-2 is the most common plasmid-mediated AmpC β-lactamase inEscherichia coliisolates of human and animal origin. The aim of this study was to elucidate the epidemiology of CMY-2-producingE. coliin Denmark. Strain and plasmid relatedness was studied in 93 CMY-2-producing clinical and commensalE. coliisolates collected from 2006 to 2012 from humans, retail poultry meat, broilers, and dogs. Multilocus sequence typing (MLST), antimicrobial susceptibility testing, and conjugation were performed in conjunction with plasmid replicon typing, plasmid multilocus sequence typing (pMLST), restriction fragment length polymorphism (RFLP), and sequencing of selectedblaCMY-2-harboring plasmids. MLST revealed high strain diversity, with fewE. colilineages occurring in multiple host species and sample types.blaCMY-2was detected on plasmids in 83 (89%) isolates. Most (75%) of the plasmids were conjugative and did not (96%) cotransfer resistance to antimicrobials other than cephalosporins. The main replicon types identified were IncI1-Iγ (55%) and IncK (39%). Isolates from different host species mainly carried distinct plasmid subtypes. Seven of the 18 human isolates harbored IncI1-Iγ/sequence type 2 (ST2), IncI1-Iγ/ST12, or IncK plasmids highly similar to those found among animal isolates, even though highly related human and animal plasmids differed by nonsynonymous single nucleotide polymorphisms (SNPs) or insertion sequence elements. This study clearly demonstrates that the epidemiology of CMY-2 can be understood only by thorough plasmid characterization. To date, the spread of this β-lactam resistance determinant in Denmark is mainly associated with IncK and IncI1-Iγ plasmids that are generally distributed according to host-specific patterns. These baseline data will be useful to assess the consequences of the increasing human exposure to CMY-2-producingE. colivia animal sources.IMPORTANCECMY-2 is the most common plasmid-mediated AmpC β-lactamase inEscherichia coli. This β-lactamase is poorly inhibited by clavulanic acid and confers resistance to cephamycins, third-generation cephalosporins, and aztreonam. Furthermore, resistance to carbapenems has been reported inE. colias a result of production of plasmid-encoded CMY-2 β-lactamase in combination with decreased outer membrane permeability. The gene encoding CMY-2 generally resides on transferable plasmids belonging to different incompatibility groups. The prevalence of CMY-2-mediated cephalosporin resistance inE. colivaries significantly depending on the geographical region and host. This study demonstrates that the epidemiology of CMY-2 can be understood only by thorough plasmid characterization. To date, the spread of this β-lactam resistance determinant in Denmark is mainly associated with IncK and IncI1-Iγ plasmids, which are generally distributed according to host-specific patterns. These data will be useful to assess the consequences of the increasing human exposure to CMY-2-producingE. colivia animal sources.

scholarly journals L-Alanine Prototrophic Suppressors Emerge from L-Alanine Auxotroph through Stress-Induced Mutagenesis in Escherichia coli

2021 ◽  
Vol 9 (3) ◽  
pp. 472
Author(s):  
Harutaka Mishima ◽  
Hirokazu Watanabe ◽  
Kei Uchigasaki ◽  
So Shimoda ◽  
Shota Seki ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pyruvate Dehydrogenase ◽  
Pyruvate Dehydrogenase Complex ◽  
Spontaneous Mutation ◽  
Point Mutations ◽  
Whole Genome Analysis ◽  
E Coli ◽  
Clone Pair ◽  
Induced Mutagenesis ◽  
Isogenic Mutants

In Escherichia coli, L-alanine is synthesized by three isozymes: YfbQ, YfdZ, and AvtA. When an E. coli L-alanine auxotrophic isogenic mutant lacking the three isozymes was grown on L-alanine-deficient minimal agar medium, L-alanine prototrophic mutants emerged considerably more frequently than by spontaneous mutation; the emergence frequency increased over time, and, in an L-alanine-supplemented minimal medium, correlated inversely with L-alanine concentration, indicating that the mutants were derived through stress-induced mutagenesis. Whole-genome analysis of 40 independent L-alanine prototrophic mutants identified 16 and 18 clones harboring point mutation(s) in pyruvate dehydrogenase complex and phosphotransacetylase-acetate kinase pathway, which respectively produce acetyl coenzyme A and acetate from pyruvate. When two point mutations identified in L-alanine prototrophic mutants, in pta (D656A) and aceE (G147D), were individually introduced into the original L-alanine auxotroph, the isogenic mutants exhibited almost identical growth recovery as the respective cognate mutants. Each original- and isogenic-clone pair carrying the pta or aceE mutation showed extremely low phosphotransacetylase or pyruvate dehydrogenase activity, respectively. Lastly, extracellularly-added pyruvate, which dose-dependently supported L-alanine auxotroph growth, relieved the L-alanine starvation stress, preventing the emergence of L-alanine prototrophic mutants. Thus, L-alanine starvation-provoked stress-induced mutagenesis in the L-alanine auxotroph could lead to intracellular pyruvate increase, which eventually induces L-alanine prototrophy.

scholarly journals Functional expression of the eukaryotic proton pump rhodopsin OmR2 in Escherichia coli and its photochemical characterization

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Masuzu Kikuchi ◽  
Keiichi Kojima ◽  
Shin Nakao ◽  
Susumu Yoshizawa ◽  
Shiho Kawanishi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Proton Pump ◽  
Expression System ◽  
Spectroscopic Characterization ◽  
Functional Expression ◽  
Proton Pumping ◽  
E Coli ◽  
Oxyrrhis Marina ◽  
Domains Of Life

AbstractMicrobial rhodopsins are photoswitchable seven-transmembrane proteins that are widely distributed in three domains of life, archaea, bacteria and eukarya. Rhodopsins allow the transport of protons outwardly across the membrane and are indispensable for light-energy conversion in microorganisms. Archaeal and bacterial proton pump rhodopsins have been characterized using an Escherichia coli expression system because that enables the rapid production of large amounts of recombinant proteins, whereas no success has been reported for eukaryotic rhodopsins. Here, we report a phylogenetically distinct eukaryotic rhodopsin from the dinoflagellate Oxyrrhis marina (O. marina rhodopsin-2, OmR2) that can be expressed in E. coli cells. E. coli cells harboring the OmR2 gene showed an outward proton-pumping activity, indicating its functional expression. Spectroscopic characterization of the purified OmR2 protein revealed several features as follows: (1) an absorption maximum at 533 nm with all-trans retinal chromophore, (2) the possession of the deprotonated counterion (pKa = 3.0) of the protonated Schiff base and (3) a rapid photocycle through several distinct photointermediates. Those features are similar to those of known eukaryotic proton pump rhodopsins. Our successful characterization of OmR2 expressed in E. coli cells could build a basis for understanding and utilizing eukaryotic rhodopsins.

scholarly journals Virulence Properties of mcr-1-Positive Escherichia coli Isolated from Retail Poultry Meat

2021 ◽  
Vol 9 (2) ◽  
pp. 308
Author(s):  
Michaela Kubelová ◽  
Ivana Koláčková ◽  
Tereza Gelbíčová ◽  
Martina Florianová ◽  
Alžběta Kalová ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Poultry Meat ◽  
Human Populations ◽  
E Coli ◽  
Antimicrobial Resistance Genes ◽  
Mlst Type ◽  
On Line ◽  
Sequence Types

The great plasticity and diversity of the Escherichia coli genome, together with the ubiquitous occurrence, make E. coli a bacterium of world-wide concern. Of particular interest are pathogenic strains and strains harboring antimicrobial resistance genes. Overlapping virulence-associated traits between avian-source E. coli and human extraintestinal pathogenic E. coli (ExPEC) suggest zoonotic potential and safety threat of poultry food products. We analyzed whole-genome sequencing (WGS) data of 46 mcr-1-positive E. coli strains isolated from retail raw meat purchased in the Czech Republic. The investigated strains were characterized by their phylogroup—B1 (43%), A (30%), D (11%), E (7%), F (4%), B2 (2%), C (2%), MLST type, and serotype. A total of 30 multilocus sequence types (STs), of which ST744 was the most common (11%), were identified, with O8 and O89 as the most prevalent serogroups. Using the VirulenceFinder tool, 3 to 26 virulence genes were detected in the examined strains and a total of 7 (15%) strains met the pathogenic criteria for ExPEC. Four strains were defined as UPEC (9%) and 18 (39%) E. coli strains could be classified as APEC. The WGS methods and available on-line tools for their evaluation enable a comprehensive approach to the diagnosis of virulent properties of E. coli strains and represent a suitable and comfortable platform for their detection. Our results show that poultry meat may serve as an important reservoir of strains carrying both virulence and antibiotic resistance genes for animal and human populations.

Polyester Cloth–Based Hybridization Array System for Identification of Enterohemorrhagic Escherichia coli Serogroups O26, O45, O103, O111, O121, O145, and O157

2012 ◽  
Vol 75 (9) ◽  
pp. 1691-1697 ◽  
Author(s):  
BURTON W. BLAIS ◽  
MARTINE GAUTHIER ◽  
MYLÈNE DESCHÊNES ◽  
GEORGE HUSZCZYNSKI
Keyword(s):  
Escherichia Coli ◽  
Marker Gene ◽  
Enterohemorrhagic Escherichia Coli ◽  
Oligonucleotide Probes ◽  
E Coli ◽  
Polyester Cloth ◽  
Gene Profiles ◽  
Pcr Products ◽  
Different Strains ◽  
Immunoenzymatic Assay

A cloth-based hybridization array system (CHAS) was developed for the identification of foodborne colony isolates of seven priority enterohemorrhagic Escherichia coli (EHEC-7) serogroups targeted by U.S. food inspection programs. Gene sequences associated with intimin; Shiga-like toxins 1 and 2; and the antigenic markers O26, O45, O103, O111, O121, O145, and O157 were amplified in a multiplex PCR incorporating a digoxigenin label, and detected by hybridization of the PCR products with an array of specific oligonucleotide probes immobilized on a polyester cloth support, with subsequent immunoenzymatic assay of the captured amplicons. The EHEC-7 CHAS exhibited 100% inclusivity and 100% exclusivity characteristics with respect to detection of the various markers among 89 different E. coli strains, with various marker gene profiles and 15 different strains of non–E. coli bacteria.

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