Progressive Development of Cefiderocol Resistance in Escherichia coli During Therapy Is Associated with Increased blaNDM-5 Copy Number and Gene Expression

Author(s):  
Patricia J Simner ◽  
Heba H Mostafa ◽  
Yehudit Bergman ◽  
Michael Ante ◽  
Tsigereda Tekle ◽  
...  

Abstract Background As cefiderocol is increasingly being prescribed in clinical practice, it is critical that we understand key mechanisms contributing to acquired resistance to this agent. Methods We report the case of a patient with acute lymphoblastic leukemia with an NDM-5 producing Escherichia coli intra-abdominal infection where resistance to cefiderocol evolved approximately 2 weeks after initiating cefiderocol therapy. Through WGS investigations, mRNA expression studies, and EDTA inhibition analysis, we investigate the role of increased NDM-5 production and genetic mutations contributing to the development of cefiderocol resistance using 5 sequential clinical E. coli isolates obtained from the patient. Results blaNDM-5 genes were identified in all 5 isolates. Cefiderocol MICs were 2, 4, and >32 mcg/mL for isolates 1-2, 3, 4-5, respectively. WGS showed that isolates 1-3 contained a single copy of the blaNDM-5 gene, whereas isolates 4 and 5 had 5 copies and 10 copies of the blaNDM-5 gene on an IncFIA/FIB/IncFII plasmid, respectively. These findings correlated with NDM-5 mRNA expression analysis in which isolates 4 and 5 expressed NDM 1.7x and 2.8x greater than isolate 1. Synergy testing with the combination of ceftazidime-avibactam and aztreonam demonstrated expansion of the zone of inhibition between the disks for all isolates. The patient was eventually successfully treated with this combination and remained infection free 10 months later. Conclusions Our patient’s case suggests that increased copy numbers of bla NDM genes through translocation events is used by Enterobacterales to evade cefiderocol-mediated cell death. The frequency of increased NDM expression in contributing to cefiderocol resistance needs investigation.

2017 ◽  
Vol 61 (5) ◽  
Author(s):  
Erik Snesrud ◽  
Ana C. Ong ◽  
Brendan Corey ◽  
Yoon I. Kwak ◽  
Robert Clifford ◽  
...  

ABSTRACT The emergence of a transferable colistin resistance gene (mcr-1) is of global concern. The insertion sequence ISApl1 is a key component in the mobilization of this gene, but its role remains poorly understood. Six Escherichia coli isolates were cultured from the same patient over the course of 1 month in Germany and the United States after a brief hospitalization in Bahrain for an unconnected illness. Four carried mcr-1 as determined by real-time PCR, but two were negative. Two additional mcr-1-negative E. coli isolates were collected during follow-up surveillance 9 months later. All isolates were analyzed by whole-genome sequencing (WGS). WGS revealed that the six initial isolates were composed of two distinct strains: an initial ST-617 E. coli strain harboring mcr-1 and a second, unrelated, mcr-1-negative ST-32 E. coli strain that emerged 2 weeks after hospitalization. Follow-up swabs taken 9 months later were negative for the ST-617 strain, but the mcr-1-negative ST-32 strain was still present. mcr-1 was associated with a single copy of ISApl1, located on a 64.5-kb IncI2 plasmid that shared >95% homology with other mcr-1 IncI2 plasmids. ISApl1 copy numbers ranged from 2 for the first isolate to 6 for the final isolate, but ISApl1 movement was independent of mcr-1. Some movement was accompanied by gene disruption, including the loss of genes encoding proteins involved in stress responses, arginine catabolism, and l-arabinose utilization. These data represent the first comprehensive analysis of ISApl1 movement in serial clinical isolates and reveal that, under certain conditions, ISApl1 is a highly active IS element whose movement may be detrimental to the host cell.


Genetics ◽  
1998 ◽  
Vol 148 (4) ◽  
pp. 1441-1451
Author(s):  
Johan G de Boer ◽  
Barry W Glickman

Abstract The lacI gene has been used extensively for the recovery and analysis of mutations in bacteria with various DNA repair backgrounds and after exposure to a wide variety of mutagens. This has resulted in a large database of information on mutational mechanisms and specificity of many mutagens, as well as the effect of DNA repair background on mutagenicity. Most importantly, knowledge about the mutational sensitivity of the lacI gene is now available, yielding information about mutable nucleotides. This popularity and available knowledge resulted in the use of the lacI gene in transgenic rodents for the study of mutagenesis in mammals, where it resides in ~40 repeated copies. As the number of sequenced mutations recovered from these animals increases, we are able to analyze the sites at which mutations have been recovered in great detail and to compare the recovered sites between bacteria and transgenic animals. The nucleotides that code for the DNA-binding domain are nearly saturated with base substitutions. Even after determining the sequences of ~10,000 mutations recovered from the animals, however, new sites and new changes are still being recovered. In addition, we compare the nature of deletion mutations between bacteria and animals. Based on the nature of deletions in the animals, we conclude that each deletion occurs in a single copy of the gene.


2021 ◽  
Vol 9 (3) ◽  
pp. 651
Author(s):  
Alice Roedel ◽  
Szilvia Vincze ◽  
Michaela Projahn ◽  
Uwe Roesler ◽  
Caroline Robé ◽  
...  

Biocides are frequently applied as disinfectants in animal husbandry to prevent the transmission of drug-resistant bacteria and to control zoonotic diseases. Concerns have been raised, that their use may contribute to the selection and persistence of antimicrobial-resistant bacteria. Especially, extended-spectrum β-lactamase- and AmpC β-lactamase-producing Escherichia coli have become a global health threat. In our study, 29 ESBL-/AmpC-producing and 64 NON-ESBL-/AmpC-producing E.coli isolates from three German broiler fattening farms collected in 2016 following regular cleaning and disinfection were phylogenetically characterized by whole genome sequencing, analyzed for phylogenetic distribution of virulence-associated genes, and screened for determinants of and associations between biocide tolerance and antibiotic resistance. Of the 30 known and two unknown sequence types detected, ST117 and ST297 were the most common genotypes. These STs are recognized worldwide as pandemic lineages causing disease in humans and poultry. Virulence determinants associated with extraintestinal pathogenic E.coli showed variable phylogenetic distribution patterns. Isolates with reduced biocide susceptibility were rarely found on the tested farms. Nine isolates displayed elevated MICs and/or MBCs of formaldehyde, chlorocresol, peroxyacetic acid, or benzalkonium chloride. Antibiotic resistance to ampicillin, trimethoprim, and sulfamethoxazole was most prevalent. The majority of ESBL-/AmpC-producing isolates carried blaCTX-M (55%) or blaCMY-2 (24%) genes. Phenotypic biocide tolerance and antibiotic resistance were not interlinked. However, biocide and metal resistance determinants were found on mobile genetic elements together with antibiotic resistance genes raising concerns that biocides used in the food industry may lead to selection pressure for strains carrying acquired resistance determinants to different antimicrobials.


2002 ◽  
Vol 98 (4) ◽  
pp. 485-492 ◽  
Author(s):  
Matthew J. Scanlan ◽  
Claudia M. Gordon ◽  
Barbara Williamson ◽  
Sang-Yull Lee ◽  
Yao-Tseng Chen ◽  
...  

2018 ◽  
Vol 109 (2) ◽  
pp. 248-256
Author(s):  
E. Meng ◽  
J. Li ◽  
B. Tang ◽  
Y. Hu ◽  
T. Qiao ◽  
...  

AbstractAlthough parasites and microbial pathogens are both detrimental to insects, little information is currently available on the mechanism involved in how parasitized hosts balance their immune responses to defend against microbial infections. We addressed this in the present study by comparing the immune response between unparasitized and parasitized pupae of the chrysomelid beetle, Octodonta nipae (Maulik), to Escherichia coli invasion. In an in vivo survival assay, a markedly reduced number of E. coli colony-forming units per microliter was detected in parasitized pupae at 12 and 24 h post-parasitism, together with decreased phagocytosis and enhanced bactericidal activity at 12 h post-parasitism. The effects that parasitism had on the mRNA expression level of selected antimicrobial peptides (AMPs) of O. nipae pupae showed that nearly all transcripts of AMPs examined were highly upregulated during the early and late parasitism stages except defensin 2B, whose mRNA expression level was downregulated at 24 h post-parasitism. Further elucidation on the main maternal fluids responsible for alteration of the primary immune response against E. coli showed that ovarian fluid increased phagocytosis at 48 h post-injection. These results indicated that the enhanced degradation of E. coli in parasitized pupae resulted mainly from the elevated bactericidal activity without observing the increased transcripts of target AMPs. This study contributes to a better understanding of the mechanisms involved in the immune responses of a parasitized host to bacterial infections.


2019 ◽  
Author(s):  
Denise van Hout ◽  
Tess D. Verschuuren ◽  
Patricia C.J. Bruijning-Verhagen ◽  
Thijs Bosch ◽  
Anita C. Schürch ◽  
...  

ABSTRACTBackgroundKnowledge on the molecular epidemiology of Escherichia coli causing E. coli bacteremia (ECB) in the Netherlands is mostly based on extended-spectrum beta-lactamase-producing E. coli (ESBL-Ec). We determined differences in clonality and resistance and virulence gene (VG) content between non-ESBL-producing E. coli (non-ESBL-Ec) and ESBL-Ec blood isolates with different epidemiological characteristics.Materials/methodsA random selection of non-ESBL-Ec isolates as well as all available ESBL-Ec blood isolates was obtained from two Dutch hospitals between 2014 and 2016. Whole genome sequencing was performed to infer sequence types (STs), serotypes, acquired antibiotic resistance genes and VG scores, based on presence of 49 predefined putative pathogenic VG.ResultsST73 was most prevalent among the 212 non-ESBL-Ec (N=26, 12.3%) and ST131 among the 69 ESBL-Ec (N=30, 43.5%). Prevalence of ST131 among non-ESBL-Ec was 10.4% (N=22, P value < 0.001 compared to ESBL-Ec). O25:H4 was the most common serotype in both non-ESBL-Ec and ESBL-Ec. Median acquired resistance gene counts were 1 (IQR 1 – 6) and 7 (IQR 4 – 9) for non-ESBL-Ec and ESBL-Ec, respectively (P value < 0.001). Among non-ESBL-Ec, acquired resistance gene count was highest among blood isolates from a primary gastro-intestinal focus (median 4, IQR 1 – 8). Median VG scores were 13 (IQR 9 – 20) and 12 (IQR 8 – 14) for non-ESBL-Ec and ESBL-Ec, respectively (P value = 0.002). VG scores among non-ESBL-Ec from a primary urinary focus (median 15, IQR 11 – 21) were higher compared to non-ESBL-Ec from a primary gastro-intestinal (median 10, IQR 6 – 13) or hepatic-biliary focus (median 11, IQR 5 – 18) (P values = 0.007 and 0.036, respectively). VG content varied between different E. coli STs.ConclusionsNon-ESBL-Ec and ESBL-Ec blood isolates from two Dutch hospitals differed in clonal distribution, resistance gene and VG content. Also, resistance gene and VG content differed between non-ESBL-Ec from different primary foci of ECB.


2000 ◽  
Vol 182 (16) ◽  
pp. 4443-4452 ◽  
Author(s):  
Tim Zeppenfeld ◽  
Christina Larisch ◽  
Joseph W. Lengeler ◽  
Knut Jahreis

ABSTRACT In Escherichia coli K-12, the major glucose transporter with a central role in carbon catabolite repression and in inducer exclusion is the phosphoenolpyruvate-dependent glucose:phosphotransferase system (PTS). Its membrane-bound subunit, IICBGlc, is encoded by the gene ptsG; its soluble domain, IIAGlc, is encoded by crr, which is a member of the pts operon. The system is inducible by d-glucose and, to a lesser degree, byl-sorbose. The regulation of ptsG transcription was analyzed by testing the induction of IICBGlctransporter activity and of a single-copy Φ(ptsGop-lacZ) fusion. Among mutations found to affect directly ptsGexpression were those altering the activity of adenylate cyclase (cyaA), the repressor DgsA (dgsA; also called Mlc), the general PTS proteins enzyme I (ptsI) and histidine carrier protein HPr (ptsH), and the IIAGlc and IIBGlc domains, as well as several authentic and newly isolated UmgC mutations. The latter, originally thought to map in the repressor gene umgC outside theptsG locus, were found to represent ptsGalleles. These affected invariably the substrate specificity of the IICBGlc domain, thus allowing efficient transport and phosphorylation of substrates normally transported very poorly or not at all by this PTS. Simultaneously, all of these substrates became inducers for ptsG. From the analysis of the mutants, fromcis-trans dominance tests, and from the identification of the amino acid residues mutated in the UmgC mutants, a new regulatory mechanism involved in ptsG induction is postulated. According to this model, the phosphorylation state of IIBGlc modulates IICGlc which, directly or indirectly, controls the repressor DgsA and hence ptsGexpression. By the same mechanism, glucose uptake and phosphorylation also control the expression of the pts operon and probably of all operons controlled by the repressor DgsA.


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