scholarly journals Genome-wide screening and characterization of genes involved in response to high dose of ciprofloxacin in Escherichia coli

2020 ◽  
Author(s):  
Rui Sun ◽  
Chunmei Zhang ◽  
Xianqi Zhao ◽  
Xue Han ◽  
Qian Zhao ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Gene Clusters ◽  
Cellular Protein ◽  
High Dose ◽  
Repair System ◽  
High Concentration ◽  
Dna Damage And Repair ◽  
Detoxification System

Abstract Background Antibiotic resistance is an urgent threat to public health. Prior to the evolution of antibiotic resistance, bacteria frequently undergo response and tend to develop a state of adaption to the antibiotic. Ciprofloxacin is a broad-spectrum antibiotic by damaging DNA. With the widespread clinical application, the resistance of bacteria to ciprofloxacin continues to increase. This study aimed to investigate the transcriptome changes under the action of high concentration of ciprofloxacin in Escherichia coli. Results We identified 773 higher expressed differentially expressed genes (DEGs) and 645 lower expressed DEGs in ciprofloxacin treated cells. Enriched biological pathways reflected the up-regulation of biological process such as DNA damage and repair system, toxin/antitoxin systems, formaldehyde detoxification system, peptide biosynthetic process and cellular protein metabolic process. With KEGG pathway analysis, higher expressed DEGs of kdsA and waa operon were associated with “LPS biosynthesis”. rfbABC operon was related to “streptomycin biosynthesis” and “polyketide sugar unit biosynthesis ”. Lower expressed DEGs of thrABC and fliL operons were associated with “flagellum-dependent cell motility” and “bacterial-type flagellum” in GO terms, and enriched into “biosynthesis of amino acids” and “flagellar assembly” in KEGG pathways. After treatment of ciprofloxacin, bacterial lipopolysacchride (LPS) release was increased by two times, and the mRNA expression level of LPS synthesis genes, waaB, waaP and waaG were elevated (P < 0.05). Conclusions Characterization of the gene clusters by RNA-seq showed high dose of ciprofloxacin not only lead to damage of bacterial macromolecules and components, but also induce protective response against antibiotic action by up-regulating the SOS system, toxin/antitoxin system and formaldehyde detoxification system. Moreover, genes related to biosynthesis of LPS were also higher expressed by the treatment indicating that ciprofloxacin can enhance the production of endotoxin on the level of transcription. These results demonstrated that transient exposure of high dose ciprofloxacin is double edged. Cautions should be taken when administering the high dose antibiotic treatment for infectious diseases.

scholarly journals In vivo characterization of the activities of novel cyclodipeptide oxidases: new tools for increasing chemical diversity of bioproduced 2,5-diketopiperazines in Escherichia coli

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Fabien Le Chevalier ◽  
Isabelle Correia ◽  
Lucrèce Matheron ◽  
Morgan Babin ◽  
Mireille Moutiez ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Biological Activities ◽  
Gene Clusters ◽  
Chemical Diversity ◽  
E Coli ◽  
Chemical Structures ◽  
In Vivo Characterization ◽  
Culture Supernatants

Abstract Background Cyclodipeptide oxidases (CDOs) are enzymes involved in the biosynthesis of 2,5-diketopiperazines, a class of naturally occurring compounds with a large range of pharmaceutical activities. CDOs belong to cyclodipeptide synthase (CDPS)-dependent pathways, in which they play an early role in the chemical diversification of cyclodipeptides by introducing Cα-Cβ dehydrogenations. Although the activities of more than 100 CDPSs have been determined, the activities of only a few CDOs have been characterized. Furthermore, the assessment of the CDO activities on chemically-synthesized cyclodipeptides has shown these enzymes to be relatively promiscuous, making them interesting tools for cyclodipeptide chemical diversification. The purpose of this study is to provide the first completely microbial toolkit for the efficient bioproduction of a variety of dehydrogenated 2,5-diketopiperazines. Results We mined genomes for CDOs encoded in biosynthetic gene clusters of CDPS-dependent pathways and selected several for characterization. We co-expressed each with their associated CDPS in the pathway using Escherichia coli as a chassis and showed that the cyclodipeptides and the dehydrogenated derivatives were produced in the culture supernatants. We determined the biological activities of the six novel CDOs by solving the chemical structures of the biologically produced dehydrogenated cyclodipeptides. Then, we assessed the six novel CDOs plus two previously characterized CDOs in combinatorial engineering experiments in E. coli. We co-expressed each of the eight CDOs with each of 18 CDPSs selected for the diversity of cyclodipeptides they synthesize. We detected more than 50 dehydrogenated cyclodipeptides and determined the best CDPS/CDO combinations to optimize the production of 23. Conclusions Our study establishes the usefulness of CDPS and CDO for the bioproduction of dehydrogenated cyclodipeptides. It constitutes the first step toward the bioproduction of more complex and diverse 2,5-diketopiperazines.

scholarly journals Antibiotic resistance and molecular characterization of bacteremia Escherichia coli isolates from newborns in the United States

PLoS ONE ◽  
2019 ◽  
Vol 14 (7) ◽  
pp. e0219352 ◽  
Author(s):  
Bryan K. Cole ◽  
Marko Ilikj ◽  
Cindy B. McCloskey ◽  
Susana Chavez-Bueno
Keyword(s):  
United States ◽  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Molecular Characterization ◽  
The United States

Further characterization of Escherichia coli O153:H45, an ETEC serotype disseminated in Chile

1988 ◽  
Vol 34 (1) ◽  
pp. 85-88 ◽  
Author(s):  
M. Elena Fernández-Beroš ◽  
Vincent Kissel ◽  
Maria E. Agüero ◽  
Guillermo Figueroa ◽  
Karen D'Ottone ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Enterotoxigenic Escherichia Coli ◽  
Plasmid Content ◽  
Enterotoxin Genes ◽  
Metabolic Properties ◽  
Factor Antigen

The newly described stable enterotoxin producing, enterotoxigenic Escherichia coli, serotype O153:H45, capable of expressing colonizing factor antigen I, is frequently isolated as a cause of diarrhea among Chilean children. Hybridization studies of five new strains confirmed previous results which indicated that the stable enterotoxin genes are contained in nonconjugative plasmids ranging in size from 81 to 87 kilobases. The strains expressed similar antibiotic resistance and metabolic properties but differed in their plasmid content.

Characterization of Antibiotic Resistance E. Coli and Antibiotic Resistance Genes in Aquatic Environment of Taihu Lake, China

2013 ◽  
Vol 295-298 ◽  
pp. 630-634 ◽  
Author(s):  
Ni Ni Han ◽  
Song He Zhang ◽  
Pei Fang Wang ◽  
Chao Wang
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Surface Water ◽  
Resistance Genes ◽  
Taihu Lake ◽  
Antibiotic Resistance Genes ◽  
Antibiotic Resistant ◽  
E Coli ◽  
Realtime Pcr

The aims of this study are to evaluate multiple antibiotic resistant Escherichia coli isolated from surface water and to investigate the presence and distribution antibiotic resistance genes (ARGs) in sediments of Taihu Lake. The results show that the presentence of four ARGs concentrations in the sediments of the lake was in sequence: strB>qnrB>strA>qnrS, as determined by realtime-PCR technique. The southwest and east areas of Taihu Lake were polluted seriously than other areas from all kinds of antibiotics. The screening Escherichia coli had a higher resistance to streptomycin, tetracycline and ampicillin than other four antibiotics, and had a lowest resistance to levofloxacin.

Genetic Organization of the Escherichia coli K10 Capsule Gene Cluster: Identification and Characterization of Two Conserved Regions in Group III Capsule Gene Clusters Encoding Polysaccharide Transport Functions

1999 ◽  
Vol 181 (7) ◽  
pp. 2279-2285 ◽  
Author(s):  
Bradley R. Clarke ◽  
Rowan Pearce ◽  
Ian S. Roberts
Keyword(s):  
Escherichia Coli ◽  
Gene Cluster ◽  
Gene Clusters ◽  
Group Iii ◽  
Genetic Organization ◽  
Conserved Regions ◽  
Cluster Identification ◽  
Capsule Production ◽  
Identification And Characterization

ABSTRACT Analysis of the Escherichia coli K10 capsule gene cluster identified two regions, regions 1 and 3, conserved between different group III capsule gene clusters. Region 1 encodes homologues of KpsD, KpsM, KpsT, and KpsE proteins, and region 3 encodes homologues of the KpsC and KpsS proteins. An rfaH mutation abolished K10 capsule production, suggesting that expression of the K10 capsule was regulated by RfaH in a manner analogous to group II capsule gene clusters. An IS3 element and a φR73-like prophage, both of which may have played a role in the acquisition of group III capsule gene clusters, were detected flanking the K10 capsule genes.

scholarly journals Characterization of Integrons and Antimicrobial Resistance in Escherichia coli Sequence Type 131 Isolates

2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Jiangqing Huang ◽  
Fangjun Lan ◽  
Yanfang Lu ◽  
Bin Li
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Sequence Type ◽  
Broth Culture ◽  
Gene Cassettes ◽  
E Coli ◽  
Class 1

Background. Escherichia coli sequence type 131 (ST131) is an important multidrug-resistant extraintestinal pathogen, which can cause many kinds of infections. Integrons may play a crucial role in the dissemination of antibiotic resistance genes. The purpose of this study was to characterize the prevelance of integrons among E. coli ST131 strains in China. Methods. Eighty-three E. coli ST131 isolates were used in this study. The antibiotic susceptibility test was performed by the disk diffusion method. The presence and characterization of class 1, 2, and 3 integrons, as well as promotor of gene cassettes and other antimicrobial resistance genes, were detected by PCR and DNA sequencing. Transfer of integrons was carried out using a broth culture mating method. Clonal relatedness of E. coli ST131 isolates was analyzed by PFGE. Results. Overall, 26.5% (22/83) of the E. coli ST131 isolates carried class 1 integrons. Class 2 and 3 integrons were not found in this study. Two types of gene cassette arrays were demonstrated in this study and were as follows: dfrA17-aadA5 and aac(6′)-Ib-cr-cmlA5. Only one type of Pc promoter variant was detected among 22 integron-positive isolates (PcW). In vivo transfer of integron was successful for 9 of integron-positive E. coli ST131 isolates harboring resistance gene cassettes. Results of PFGE demonstrated that the integron-positive E. coli ST131 isolates were grouped into 12 different PFGE clusters. Conclusions. Our study showed a low prevalence of integrons was detected in E. coli ST131. Continued surveillance of this mobile genetic element should be performed to study the evolution of antibiotic resistance among E. coli ST131.

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