Unusual codon bias occurring within insertion sequences in Escherichia coli

Genetica ◽  
1991 ◽  
Vol 84 (1) ◽  
pp. 23-29 ◽  
Author(s):  
J. G. Lawrence ◽  
D. L. Hartl
2018 ◽  
Vol 62 (3) ◽  
pp. e02453-17 ◽  
Author(s):  
Stefano Mancini ◽  
Laurent Poirel ◽  
Nicolas Kieffer ◽  
Patrice Nordmann

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).


Author(s):  
Madubuike Umunna Anyanwu ◽  
Ishmael Festus Jaja ◽  
Obichukwu Chisom Nwobi

The emergence and spread of mobile colistin (COL) resistance (mcr) genes jeopardize the efficacy of COL, a last resort antibiotic for treating deadly infections. COL has been used in livestock for decades globally. Bacteria have mobilized mcr genes (mcr-1 to mcr-9). Mcr-gene-containing bacteria (MGCB) have disseminated by horizontal/lateral transfer into diverse ecosystems, including aquatic, soil, botanical, wildlife, animal environment, and public places. The mcr-1, mcr-2, mcr-3, mcr-5, mcr-7, and mcr-8 have been detected in isolates from and/or directly in environmental samples. These genes are harboured by Escherichia coli, Enterobacter, Klebsiella, Proteus, Salmonella, Citrobacter, Pseudomonas, Acinetobacter, Kluyvera, Aeromonas, Providencia, and Raulotella isolates. Different conjugative and non-conjugative plasmids form the backbones for mcr in these isolates, but mcr have also been integrated into the chromosome of some strains. Insertion sequences (IS) (especially ISApl1) located upstream or downstream of mcr, class 1–3 integrons, and transposons are other drivers of mcr in the environment. Genes encoding multi-/extensive-drug resistance and virulence are often co-located with mcr on plasmids in environmental isolates. Transmission of mcr to/among environmental strains is clonally unrestricted. Contact with the mcr-containing reservoirs, consumption of contaminated animal-/plant-based foods or water, international animal-/plant-based food trades and travel, are routes for transmission of MGCB.


Biochimie ◽  
1991 ◽  
Vol 73 (11) ◽  
pp. 1361-1374 ◽  
Author(s):  
I MOSZER ◽  
P GLASER ◽  
A DANCHIN

2007 ◽  
Vol 51 (8) ◽  
pp. 2855-2860 ◽  
Author(s):  
Marie-Frédérique Lartigue ◽  
Catherine Zinsius ◽  
Aline Wenger ◽  
Jacques Bille ◽  
Laurent Poirel ◽  
...  

ABSTRACT The epidemiology of clavulanic acid-inhibited extended-spectrum β-lactamases (ESBLs) was investigated among infection-associated enterobacterial isolates at the University Hospital in Lausanne, Switzerland, from January 2004 to June 2005. Out of 57 nonrepetitive ESBL producers (prevalence rate of 0.7%), 45 produced CTX-M-like ESBLs. CTX-M enzymes were mostly from clonally nonrelated Escherichia coli isolates, from urinary infections and community-acquired infections. Pediatric patients (20 out of 57) accounted for a large number of CTX-M producers. CTX-M-15 was the most frequent CTX-M-type enzyme. The plasmid-located bla CTX-M genes were associated with either ISEcp1 or ISCR1 insertion sequences. This study is the first published report of CTX-M-type β-lactamases in Switzerland.


2016 ◽  
Vol 60 (8) ◽  
pp. 5014-5017 ◽  
Author(s):  
Jian Sun ◽  
Xing-Ping Li ◽  
Run-Shi Yang ◽  
Liang-Xing Fang ◽  
Wei Huo ◽  
...  

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.


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