scholarly journals Transposition of Tn1213Encoding the PER-1 Extended-Spectrum β-Lactamase

2018 ◽  
Vol 62 (3) ◽  
pp. e02453-17 ◽  
Author(s):  
Stefano Mancini ◽  
Laurent Poirel ◽  
Nicolas Kieffer ◽  
Patrice Nordmann
Keyword(s):  
Escherichia Coli ◽  
Low Frequency ◽  
Insertion Sequences ◽  
Content Type ◽  
Very Low Frequency ◽  
Extended Spectrum

ABSTRACTPER-1 is an extended-spectrum β-lactamase that is encoded by a gene located in composite transposon Tn1213made by two distinct insertion sequences, namely, ISPa12and ISPa13. In vitromobilization performed inEscherichia colishows that Tn1213is functional and is able to mobilize theblaPER-1gene, although at a very low frequency (ca. 1 × 10−9).

scholarly journals Complete Nucleotide Sequence of an IncI2 Plasmid CoharboringblaCTX-M-55andmcr-1

2016 ◽  
Vol 60 (8) ◽  
pp. 5014-5017 ◽  
Author(s):  
Jian Sun ◽  
Xing-Ping Li ◽  
Run-Shi Yang ◽  
Liang-Xing Fang ◽  
Wei Huo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Nucleotide Sequence ◽  
Complete Nucleotide Sequence ◽  
Sequence Similarity ◽  
Conjugative Plasmid ◽  
Insertion Sequences ◽  
Content Type ◽  
Extensive Sequence ◽  
Extended Spectrum ◽  
Lactamase Gene

ABSTRACTWe report the complete nucleotide sequence of a plasmid, pA31-12, carryingblaCTX-M-55andmcr-1from a chickenEscherichia coliisolate. pA31-12 has an IncI2 replicon that displays extensive sequence similarity with pHN1122-1-borneblaCTX-M-55and pHNSHP45-bornemcr-1. Insertion sequences ISEcp1and ISApl1are responsible for the mobilization ofblaCTX-M-55andmcr-1, respectively. The colocalization ofmcr-1with an extended-spectrum β-lactamase gene on a conjugative plasmid may accelerate the dissemination of both genes by coselection.

scholarly journals In Vitro Activity of Sulopenem, an Oral Penem, against Urinary Isolates of Escherichia coli

2018 ◽  
Vol 63 (1) ◽  
Author(s):  
James A. Karlowsky ◽  
Heather J. Adam ◽  
Melanie R. Baxter ◽  
Andrew J. Denisuik ◽  
Philippe R. S. Lagacé-Wiens ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Multidrug Resistant ◽  
Vitro Activity ◽  
In Vitro Activity ◽  
Broth Microdilution ◽  
Content Type ◽  
Extended Spectrum ◽  
Urinary Isolates

ABSTRACT The in vitro activity of sulopenem was assessed against a collection from 2014 to 2016 of 539 urinary isolates of Escherichia coli from Canadian patients by using CLSI-defined broth microdilution methodology. A concentration of sulopenem 0.03 µg/ml inhibited both 50% (MIC50) and 90% (MIC90) of isolates tested; sulopenem MICs ranged from 0.015 to 0.25 µg/ml. The in vitro activity of sulopenem was unaffected by nonsusceptibility to trimethoprim-sulfamethoxazole and/or ciprofloxacin, multidrug-resistant phenotypes, extended-spectrum β-lactamases, or AmpC β-lactamases.

scholarly journals In VitroActivities of 21 Antimicrobial Agents Alone and in Combination with Aminoglycosides or Fluoroquinolones against Extended-Spectrum-β-Lactamase-Producing Escherichia coli Isolates Causing Bacteremia

2015 ◽  
Vol 59 (9) ◽  
pp. 5834-5837 ◽  
Author(s):  
Min Kyeong Cha ◽  
Cheol-In Kang ◽  
So Hyun Kim ◽  
Sun Young Cho ◽  
Young Eun Ha ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Therapy ◽  
Antimicrobial Agents ◽  
Empirical Therapy ◽  
Gram Negative ◽  
Content Type ◽  
South Korean ◽  
Extended Spectrum ◽  
High Prevalence

ABSTRACTWe evaluated thein vitroactivity of various antimicrobials alone and in combination against 291 extended-spectrum-β-lactamase-producingEscherichia coli(ESBL-EC) isolates causing bacteremia in South Korean hospitals. Ceftazidime, cefepime, and piperacillin-tazobactam in combination with amikacin showed greater activity than found in combination with ciprofloxacin. In settings with a high prevalence of ESBL-producing pathogens, combination aminoglycoside antimicrobial therapy, especially with amikacin, may be considered for empirical therapy against suspected Gram-negative sepsis as a carbapenem-saving strategy.

scholarly journals Escherichia coli Probiotic Strain ED1a in Pigs Has a Limited Impact on the Gut Carriage of Extended-Spectrum-β-Lactamase-Producing E. coli

2016 ◽  
Vol 61 (1) ◽  
Author(s):  
G. Mourand ◽  
F. Paboeuf ◽  
M. A. Fleury ◽  
E. Jouy ◽  
S. Bougeard ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Probiotic Strain ◽  
Fecal Excretion ◽  
Experimental Conditions ◽  
Content Type ◽  
E Coli ◽  
Extended Spectrum ◽  
Probiotic Treatment ◽  
The Impact

ABSTRACT Four trials were conducted to evaluate the impact of Escherichia coli probiotic strain ED1a administration to pigs on the gut carriage or survival in manure of extended-spectrum-β-lactamase-producing E. coli. Groups of pigs were orally inoculated with strain E. coli M63 carrying the bla CTX-M-1 gene (n = 84) or used as a control (n = 26). In the first two trials, 24 of 40 E. coli M63-inoculated pigs were given E. coli ED1a orally for 6 days starting 8 days after oral inoculation. In the third trial, 10 E. coli M63-inoculated pigs were given either E. coli ED1a or probiotic E. coli Nissle 1917 for 5 days. In the fourth trial, E. coli ED1a was given to a sow and its 12 piglets, and these 12 piglets plus 12 piglets that had not received E. coli ED1a were then inoculated with E. coli M63. Fecal shedding of cefotaxime-resistant Enterobacteriaceae (CTX-RE) was studied by culture, and bla CTX-M-1 genes were quantified by PCR. The persistence of CTX-RE in manure samples from inoculated pigs or manure samples inoculated in vitro with E. coli M63 with or without probiotics was studied. The results showed that E. coli M63 and ED1a were good gut colonizers. The reduction in the level of fecal excretion of CTX-RE in E. coli ED1a-treated pigs compared to that in nontreated pigs was usually less than 1 log10 CFU and was mainly observed during the probiotic administration period. The results obtained with E. coli Nissle 1917 did not differ significantly from those obtained with E. coli ED1a. CTX-RE survival did not differ significantly in manure samples with or without probiotic treatment. In conclusion, under our experimental conditions, E. coli ED1a and E. coli Nissle 1917 could not durably prevent CTX-RE colonization of the pig gut.

scholarly journals Competition between Escherichia coli Populations with and without Plasmids Carrying a Gene Encoding Extended-Spectrum Beta-Lactamase in the Broiler Chicken Gut

2019 ◽  
Vol 85 (17) ◽  
Author(s):  
Egil A. J. Fischer ◽  
Cindy M. Dierikx ◽  
Alieda van Essen-Zandbergen ◽  
Dik Mevius ◽  
Arjan Stegeman ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Competitive Exclusion ◽  
Antibiotic Use ◽  
Beta Lactamase ◽  
Content Type ◽  
Extended Spectrum Beta Lactamase ◽  
E Coli ◽  
Extended Spectrum ◽  
Plasmid Carriage

ABSTRACT Extended-spectrum-beta-lactamase (ESBL)/AmpC-producing Escherichia coli strains are widely found in E. coli isolates from broiler feces, largely due to the presence of the blaCTX-M-1 gene on IncI1 plasmids. Plasmid carriage is theorized to cause fitness loss and thus should decrease under conditions of reduced antibiotic use. However, in vitro studies showed plasmid carriage to increase in the absence of antimicrobials, due to plasmid conjugation. We investigated whether this translates to increased levels of plasmid in the gastrointestinal tracts of chickens, where conjugation rates may be different and subtle differences in growth rates may have a larger impact on colonization. Eight groups of five chickens were orally inoculated at 4 days of age with a 0.5-ml volume containing 106 CFU/ml E. coli cells, of which 0%, 0.1%, 10%, or 100% carried the IncI1 plasmid with the gene blaCTX-M-1. At 13 time points during 41 days, fecal samples were taken from each chicken. E. coli strains with and without plasmids were quantified. Trends in E. coli subpopulations were analyzed using generalized linear mixed models, and population dynamics were studied by fitting to a mechanistic model. Trends in E. coli subpopulations were different between groups rather than between individual chickens, suggesting substantial levels of E. coli exchange between chickens in a group. The IncI1 plasmid carrying blaCTX-M-1 was transferred with conjugation coefficients at levels higher than those observed in vitro. Across groups, the plasmids disappeared or were established independently of the initial fraction of plasmid-carrying E. coli, but no major increase occurred as observed in vitro. Differences in growth rates were observed, but competitive exclusion of plasmid-carrying variants was counteracted by conjugation. IMPORTANCE Bacteria that produce extended-spectrum beta-lactamases are resistant to an important class of antimicrobials in human and veterinary medicine. Reduction in antibiotic use is expected to decrease the prevalence of resistance. However, resistance genes often lie on plasmids which can be copied and transferred to other bacteria by conjugation, so in vitro resistance was observed to increase in the absence of antimicrobials. We sought to determine whether this also occurs in the chicken gut and if competitive exclusion by similar E. coli variants without the resistance occurred. We studied the excretion of E. coli carrying IncI1 plasmids with the blaCTX-M-1 resistance gene in small groups of broiler chickens, after inoculating the chickens with E. coli suspensions containing different fractions of plasmid-carrying cells. Our results showed little variation between chickens within groups but large differences between groups that were independent of the ratio of variants with and without the plasmid and with persistence or extinction of the plasmid. However, there was no major plasmid increase as observed in vitro. We conclude that in vivo studies with sufficient independent replications are important for intervention studies on plasmid-mediated antimicrobial resistance.

scholarly journals Cefoxitin as an Alternative to Carbapenems in a Murine Model of Urinary Tract Infection Due to Escherichia coli Harboring CTX-M-15-Type Extended-Spectrum β-Lactamase

2012 ◽  
Vol 56 (3) ◽  
pp. 1376-1381 ◽  
Author(s):  
Raphaël Lepeule ◽  
Etienne Ruppé ◽  
Patrick Le ◽  
Laurent Massias ◽  
Françoise Chau ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Murine Model ◽  
Content Type ◽  
E Coli ◽  
Extended Spectrum ◽  
Drug Concentrations ◽  
Tract Infections

ABSTRACTWe investigated the efficiency of the cephamycin cefoxitin as an alternative to carbapenems for the treatment of urinary tract infections (UTIs) due toEscherichia coliproducing CTX-M-type extended-spectrum β-lactamases. The susceptible, UTI-inducingE. coliCFT073-RR strain and its transconjugant CFT073-RR Tc (pblaCTX-M-15), harboring ablaCTX-M-15carrying-plasmid, were used for all experiments. MICs of cefoxitin (FOX), ceftriaxone (CRO), imipenem (IMP), and ertapenem (ETP) for CFT073-RR and CFT073-RR Tc (pblaCTX-M-15) were 4 and 4, 0.125 and 512, 0.5 and 0.5, and 0.016 and 0.032 μg/ml, respectively. Bactericidal activity was similarly achievedin vitroagainst the two strains after 3 h of exposure to concentrations of FOX, IMI, and ETP that were 2 times the MIC, whereas CRO was not bactericidal against CFT073-RR Tc (pblaCTX-M-15). The frequencies of spontaneous mutants of the 2 strains were not higher for FOX than for IMP or ETP. In the murine model of UTIs, mice infected for 5 days were treated over 24 h. Therapeutic regimens in mice (200 mg/kg of body weight every 3 h or 4 h for FOX, 70 mg/kg every 6 h for CRO, 100 mg/kg every 2 h for IMP, and 100 mg/kg every 4 h for ETP) were chosen in order to reproduce the percentage of time that free-drug concentrations above the MIC are obtained in humans with standard regimens. All antibiotic regimens produced a significant reduction in bacterial counts (greater than 2 log10CFU) in kidneys and bladders for both strains (P< 0.001) without selecting resistant mutantsin vivo, but the reduction obtained with CRO against CFT073-RR Tc (pblaCTX-M-15) in kidneys was significantly lower than that obtained with FOX. In conclusion, FOX appears to be an effective therapeutic alternative to carbapenems for the treatment of UTIs due to CTX-M-producingE. coli.

scholarly journals A Rhodobacter sphaeroides Protein Mechanistically Similar to Escherichia coli DksA Regulates Photosynthetic Growth

mBio ◽  
2014 ◽  
Vol 5 (3) ◽  
Author(s):  
Christopher W. Lennon ◽  
Kimberly C. Lemmer ◽  
Jessica L. Irons ◽  
Max I. Sellman ◽  
Timothy J. Donohue ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Structure Function ◽  
Rhodobacter Sphaeroides ◽  
Fatty Acid Content ◽  
Regulatory Protein ◽  
Growth Conditions ◽  
Globular Domain ◽  
Content Type ◽  
E Coli

ABSTRACTDksA is a global regulatory protein that, together with the alarmone ppGpp, is required for the “stringent response” to nutrient starvation in the gammaproteobacteriumEscherichia coliand for more moderate shifts between growth conditions. DksA modulates the expression of hundreds of genes, directly or indirectly. Mutants lacking a DksA homolog exhibit pleiotropic phenotypes in other gammaproteobacteria as well. Here we analyzed the DksA homolog RSP2654 in the more distantly relatedRhodobacter sphaeroides, an alphaproteobacterium. RSP2654 is 42% identical and similar in length toE. coliDksA but lacks the Zn finger motif of theE. coliDksA globular domain. Deletion of the RSP2654 gene results in defects in photosynthetic growth, impaired utilization of amino acids, and an increase in fatty acid content. RSP2654 complements the growth and regulatory defects of anE. colistrain lacking thedksAgene and modulates transcriptionin vitrowithE. coliRNA polymerase (RNAP) similarly toE. coliDksA. RSP2654 reduces RNAP-promoter complex stabilityin vitrowith RNAPs fromE. coliorR. sphaeroides, alone and synergistically with ppGpp, suggesting that even though it has limited sequence identity toE. coliDksA (DksAEc), it functions in a mechanistically similar manner. We therefore designate the RSP2654 protein DksARsp. Our work suggests that DksARsphas distinct and important physiological roles in alphaproteobacteria and will be useful for understanding structure-function relationships in DksA and the mechanism of synergy between DksA and ppGpp.IMPORTANCEThe role of DksA has been analyzed primarily in the gammaproteobacteria, in which it is best understood for its role in control of the synthesis of the translation apparatus and amino acid biosynthesis. Our work suggests that DksA plays distinct and important physiological roles in alphaproteobacteria, including the control of photosynthesis inRhodobacter sphaeroides. The study of DksARsp, should be useful for understanding structure-function relationships in the protein, including those that play a role in the little-understood synergy between DksA and ppGpp.

scholarly journals Novel Conjugative Plasmid from Escherichia coli of Swine Origin That Coharbors the Multiresistance Genecfrand the Extended-Spectrum-β-Lactamase GeneblaCTX-M-14b

2014 ◽  
Vol 59 (2) ◽  
pp. 1337-1340 ◽  
Author(s):  
Wan-Jiang Zhang ◽  
Xiu-Mei Wang ◽  
Lei Dai ◽  
Xin Hua ◽  
Zhimin Dong ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Conjugative Plasmid ◽  
Content Type ◽  
Conjugative Plasmids ◽  
Extended Spectrum ◽  
Lactamase Gene

ABSTRACTTwo porcineEscherichia coliisolates harbored thecfrgene on conjugative plasmids of 38,405 bp (pGXEC6) and 41,646 bp (pGXEC3). In these two plasmids, thecfrgene was located within a 4,612-bp region containing atnpA-IS26-cfr-IS26-Δhypelement. Plasmid pGXEC3 was almost identical to pGXEC6 except for a 3,235-bp ISEcp1-blaCTX-M-14binsertion. The colocation of the multiresistancecfrgene with an extended-spectrum-β-lactamase gene on a conjugative plasmid may support the dissemination of these genes by coselection.

scholarly journals Bactericidal Activities of Meropenem and Ertapenem against Extended-Spectrum-β-Lactamase-Producing Escherichia coli and Klebsiella pneumoniae in a Neutropenic Mouse Thigh Model

2007 ◽  
Vol 51 (4) ◽  
pp. 1481-1486 ◽  
Author(s):  
C. Andrew DeRyke ◽  
Mary Anne Banevicius ◽  
Hong Wei Fan ◽  
David P. Nicolau
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Infection Model ◽  
Bacterial Reduction ◽  
Efficacy Analysis ◽  
Percent Time ◽  
Extended Spectrum ◽  
Wide Range

ABSTRACT The purpose of this study was to examine the in vivo efficacies of meropenem and ertapenem against extended-spectrum-β-lactamase (ESBL)-producing isolates with a wide range of MICs. Human-simulated dosing regimens in mice were designed to approximate the free drug percent time above the MIC (fT>MIC) observed for humans following meropenem at 1 g every 8 h and ertapenem at 1 g every 24 h. An in vivo neutropenic mouse thigh infection model was used to examine the bactericidal effects against 31 clinical ESBL Escherichia coli and Klebsiella pneumoniae isolates and 2 non-ESBL isolates included for comparison at a standard 105 inoculum. Three isolates were examined at a high 107 inoculum as well. Meropenem displayed greater in vitro potency, with a median MIC (range) (μg/ml) of 0.125 (0.03 to 32), than did ertapenem, with 0.5 (0.012 to 128). Seven of the 31 ESBL isolates were removed from the efficacy analysis due to their inability to establish infection in the mouse model. When MICs were ≤1.5 μg/ml for ertapenem (≤0.5 μg/ml for meropenem), similar reductions in CFU (≈ 2-log kill) were observed for both ertapenem (fT>MIC ≥ 23%) and meropenem (fT>MIC ≥ 75%). Ertapenem showed bacterial regrowth for seven of eight isolates, with MICs of ≥2 μg/ml (fT>MIC ≤ 20%), while meropenem displayed antibacterial potency that varied from a static effect to a 1-log bacterial reduction in these isolates (fT>MIC = 30 to 65%). At a 107 inoculum, both agents eradicated bacteria due to adequate exposures (fT>MIC = 20 to 45%). Due to low MICs, no difference in bacterial kill was noted for the majority of ESBL isolates tested. However, for isolates with raised ertapenem MICs of ≥2 μg/ml, meropenem displayed sustained efficacy due to its greater in vitro potency and higher resultant fT>MIC.

Sign in / Sign up

Export Citation Format

Share Document