scholarly journals A Novel Polyvalent Bacteriophage vB_EcoM_swi3 Infects Pathogenic Escherichia coli and Salmonella enteritidis

2021 ◽  
Vol 12 ◽  
Author(s):  
Bingrui Sui ◽  
Lili Han ◽  
Huiying Ren ◽  
Wenhua Liu ◽  
Can Zhang
Keyword(s):  
Escherichia Coli ◽  
Salmonella Enteritidis ◽  
Burst Size ◽  
Large Subunit ◽  
Gc Content ◽  
Multidrug Resistant ◽  
Open Reading Frames ◽  
Morphological Observation ◽  
E Coli

A novel virulent bacteriophage vB_EcoM_swi3 (swi3), isolated from swine feces, lyzed 9% (6/65) of Escherichia coli and isolates 54% (39/72) of Salmonella enteritidis isolates, which were all clinically pathogenic multidrug-resistant strains. Morphological observation showed that phage swi3 belonged to the Myoviridae family with an icosahedral head (80 nm in diameter) and a contractile sheathed tail (120 nm in length). At the optimal multiplicity of infection of 1, the one-step growth analysis of swi3 showed a 25-min latent period with a burst size of 25-plaque-forming units (PFU)/infected cell. Phage swi3 remained stable both at pH 6.0–8.0 and at less than 50°C for at least 1 h. Genomic sequencing and bioinformatics analysis based on genomic sequences and the terminase large subunit showed that phage swi3 was a novel member that was most closely related to Salmonella phages and belonged to the Rosemountvirus genus. Phage swi3 harbored a 52-kb double-stranded DNA genome with 46.02% GC content. Seventy-two potential open reading frames were identified and annotated, only 15 of which had been assigned to functional genes. No gene associated with pathogenicity and virulence was identified. The effects of phage swi3 in treating pathologic E. coli infections in vivo were evaluated using a mouse model. The administration of a single intraperitoneal injection of swi3 (106 PFU) at 2 h after challenge with the E. coli strain (serotype K88) (108 colony-forming units) sufficiently protected all mice without toxic side effects. This finding highlighted that phage swi3 might be used as an effective antibacterial agent to prevent E. coli and S. enteritidis infection.

scholarly journals T4-Like Phage Bp7, a Potential Antimicrobial Agent for Controlling Drug-Resistant Escherichia coli in Chickens

2013 ◽  
Vol 79 (18) ◽  
pp. 5559-5565 ◽  
Author(s):  
Can Zhang ◽  
Wenli Li ◽  
Wenhua Liu ◽  
Ling Zou ◽  
Chen Yan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Burst Size ◽  
Multidrug Resistant ◽  
Open Reading Frames ◽  
Attractive Alternative ◽  
Drug Resistant ◽  
Animal Cells ◽  
Content Type ◽  
E Coli ◽  
Chicken Feces

ABSTRACTChicken-pathogenicEscherichia coliis severely endangering the poultry industry in China and worldwide, and antibiotic therapy is facing an increasing problem of antibiotic resistance. Bacteriophages can kill bacteria with no known activity in human or animal cells, making them an attractive alternative to antibiotics. In this study, we present the characteristics of a novel virulent bacteriophage, Bp7, specifically infecting pathogenic multidrug-resistantE. coli. Phage Bp7 was isolated from chicken feces. Bp7 belongs to the familyMyoviridae, possessing an elongated icosahedral head and contractile sheathed tail. It has a 168-kb double-stranded DNA genome. For larger yields, its optimal multiplicity of infection (MOI) to infectE. coliwas about 0.001. The latent period was 10 to 15 min, and the burst size was 90 PFU/infected cell. It was stable both at pH 5.0 to 10.0 and at 40°C or 50°C for at least 1 h. Bp7 could infect 46% of pathogenic clinicalE. colistrains. Bp7 harbored 791 open reading frames (ORFs) and 263 possible genes. Among the 263 genes, 199 possessed amino acid sequence identities with ORFs of phage T4, 62 had identities with other T4-like phages, and only one lacked any database match. The genome of Bp7 manifested obvious division and rearrangement compared to phages T4, JS98, and IME08. Bp7 is a new member of the “T4-like” genus, familyMyoviridae. Its wide host range, strong cell-killing activity, and high stability to pH make it an alternative to antimicrobials for controlling drug-resistantE. coliin chickens.

scholarly journals ISOLATION, CHARACTERIZATION AND GENOME ANALYSIS OF A NOVEL VIRULENT ESCHERICHIA COLI BACTERIOPHAGE VB_ECOM_011D4

2021 ◽  
Vol 6 ◽  
pp. 27-35
Keyword(s):  
High Throughput ◽  
High Throughput Sequencing ◽  
Phage Therapy ◽  
Burst Size ◽  
Large Subunit ◽  
Alternative Therapy ◽  
Gc Content ◽  
Open Reading Frames ◽  
Promising Alternative ◽  
E Coli

Phage therapy is a promising alternative therapy for the treatment of E. coli infection. Although the total number of phages on the earth is as high as 10 31 , the reported phages and thoroughly studied are very limited. Therefore, the continuous discovery of new phages and in-depth research will provide materials for the wide application of phage therapy in the future. In this study, a novel E. coli phage vB_EcoM_011D4 was isolated from sewage samples, and the biological characteristics were studied. Electron microscopy and homology analysis results showed that vB_EcoM_011D4 belongs to the family Myoviridae. One-step growth curve showing the latent period of vB_EcoM_011D4 was 10 min, with the burst size of 115 PFU/cell. Additionally, Phage vB_EcoM_011D4 was highly stabled under different temperatures (range 4 – 70 ℃) and pH conditions (range 6 – 10). At the same time, its genome was subjected to high-throughput sequencing and compared with the reported phages. The results of high-throughput sequencing assembly showed that vB_EcoM_011D4 is a linear, double-stranded DNA virus containing 163764 bp, with an average GC content of 40.50%, and a total of 273 open reading frames (ORFs). Genomic comparison analysis revealed that most of the ORFs were similar to Enterobacteria phage Phi1 and RB49. However, ORF147 and ORF148 putative DNA methylase family protein is less than 67% homology with already published phages. In addition, the phylogenetic analysis of terminates large subunit showed that it belongs to a new branch and shows less than 50 similarities to reported phages. There is no lysogenic, toxin or antibiotic-resistant related gene was found in the genome of vB_EcoM_011D4. In summary, vB_EcoM_011D4 is a newly discovered phage, which can be further studied for elucidating the phage diversity and it is benefits for the wide application of phage therapy.

Molecular Characterization and Genomic Analysis of Novel Phage vB_ ShiP-A7 Infecting Multidrug-Resistant Shiglla Fexneri and Escherichia Coli

2020 ◽  
Author(s):  
Jing Xu ◽  
Yu Gu ◽  
Xinyan Yu ◽  
Ruiyang Zhang ◽  
Xuesen Zhang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Case Reports ◽  
Burst Size ◽  
Shigella Flexneri ◽  
Genomic Analysis ◽  
Multidrug Resistant ◽  
Open Reading Frames ◽  
Mass Spectrometry Analysis ◽  
Spectrometry Analysis ◽  
Spherical Head

Abstract BackgroundPhage therapy has regained more attention due to the rise of multidrug-resistant (MDR) bacteria. Several case reports demonstrated clinical application of phage in resolving infections caused by MDR bacteria in recent years. ResultsWe isolated a new phage, vB_ShiP-A7, and then investigated its characteristics. Phage vB_ShiP-A7 is a member of Podoviridae that has an icosahedral spherical head and a short tail. vB_ShiP-A7 has large burst size and short replication time. vB_ShiP-A7’s genome is linear double stranded DNA composed of 40058 bp, encoding forty-three putative open reading frames. Comparative genome analysis demonstrated vB_ShiP-A7’s genome sequence is closely related to fifteen different phages (coverage 74-88%, identity 86-93%). Mass Spectrometry analysis revealed that twelve known proteins and six hypothetical proteins exist in particles of vB_ShiP-A7. Genome and proteome analyses confirmed the absence of lysogen-related proteins and toxic proteins in this phage. In addition, phage vB_ShiP-A7 can significantly reduce the growth of clinical MDR stains of Shigella flexneri and Escherichia coli in liquid culture. Furthermore, vB_ShiP-A7 can disrupt biofilms formed by Shigella flexneri or Escherichia coli in vitro. ConclusionPhage vB_ShiP-A7 is a stable novel phage, which has a strong application potential to inhibit MDR stains of Shigella flexneri and Escherichia coli. Comparing the genomes between vB_ShiP-A7 and other closely-related phages will help us better understand the evolutionary mechanism of phages.

scholarly journals Genomic Analysis of a Novel Phage Infecting the Turkey Pathogen Escherichia coli APEC O78 and Its Endolysin Activity

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1034
Author(s):  
Sangsang Deng ◽  
Qiang Xu ◽  
Yajuan Fu ◽  
Leiqin Liang ◽  
Yan Wu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Gene Annotation ◽  
Gc Content ◽  
Multidrug Resistant ◽  
Dimensional Structure ◽  
Resistant Bacteria ◽  
Local Alignment ◽  
Glycoside Hydrolase Family ◽  
E Coli ◽  
Tract Infections

Due to the increasing spread of multidrug-resistant (MDR) bacteria, phage therapy is considered one of the most promising methods for addressing MDR bacteria. Escherichia coli lives symbiotically in the intestines of humans and some animals, and most strains are beneficial in terms of maintaining a healthy digestive tract. However, some E. coli strains can cause serious zoonotic diseases, including diarrhea, pneumonia, urinary tract infections, and hemolytic uremic syndrome. In this study, we characterized a newly isolated Myoviridae phage, vB_EcoM_APEC. The phage vB_EcoM_APEC was able to infect E. coli APEC O78, which is the most common MDR E. coli serotype in turkeys. Additionally, the phage’s host range included Klebsiella pneumoniae and other E. coli strains. The genome of phage vB_EcoM_APEC (GenBank accession number MT664721) was 35,832 bp in length, with 52 putative open reading frames (ORFs) and a GC content of 41.3%. The genome of vB_EcoM_APEC exhibited low similarity (79.1% identity and 4.0% coverage) to the genome of Acinetobacter phage vB_AbaM_IME284 (GenBank no. MH853787.1) according to the nucleotide Basic Local Alignment Search Tool (BLASTn). Phylogenetic analysis revealed that vB_EcoM_APEC was a novel phage, and its genome sequence showed low similarity to other available phage genomes. Gene annotation indicated that the protein encoded by orf11 was an endolysin designated as LysO78, which exhibited 64.7% identity (91.0% coverage) with the putative endolysin of Acinetobacter baumannii phage vB_AbaM_B9. The LysO78 protein belongs to glycoside hydrolase family 19, and was described as being a chitinase class I protein. LysO78 is a helical protein with 12 α-helices containing a large domain and a small domain in terms of the predicted three-dimensional structure. The results of site-directed mutagenesis indicated that LysO78 contained the catalytic residues E54 and E64. The purified endolysin exhibited broad-spectrum bacteriolytic activity against Gram-negative strains, including the genera Klebsiella, Salmonella, Shigella, Burkholderia, Yersinia, and Pseudomonas, as well as the species Chitinimonas arctica, E. coli, Ralstonia solanacearum, and A. baumannii. An enzymatic assay showed that LysO78 had highly lytic peptidoglycan hydrolases activity (64,620,000 units/mg) against E. coli APEC O78, and that LysO78 had lytic activity in the temperature range of 4–85 °C, with an optimal temperature of 28 °C and optimal pH of 8.0, and was active at pH 3.0–12.0. Overall, the results suggested that LysO78 might be a promising therapeutic agent for controlling MDR E. coli APEC O78 and nosocomial infections caused by multidrug-resistant bacteria.

scholarly journals The complete genome and comparative analysis of the phage phiC120 infecting multidrug-resistant Escherichia coli and Salmonella strains

2021 ◽  
Vol 11 (2) ◽  
Author(s):  
Luis Amarillas ◽  
Claudia Villicaña ◽  
Luis Lightbourn-Rojas ◽  
Arturo González-Robles ◽  
Josefina León-Félix
Keyword(s):  
Escherichia Coli ◽  
Comparative Analysis ◽  
Foodborne Pathogens ◽  
Complete Genome ◽  
Multidrug Resistant ◽  
Open Reading Frames ◽  
E Coli ◽  
Protein Levels ◽  
Double Stranded Dna ◽  
Genes Encoding

Abstract Phages infecting Salmonella and Escherichia coli are promising agents for therapeutics and biological control of these foodborne pathogens, in particular those strains with resistance to several antibiotics. In an effort to assess the potential of the phage phiC120, a virulent phage isolated from horse feces in Mexico, we characterized its morphology, host range and complete genome. Herein, we showed that phiC120 possesses strong lytic activity against several multidrug-resistant E. coli O157: H7 and Salmonella strains, and its morphology indicated that is a member of Myoviridae family. The phiC120 genome is double-stranded DNA and consists of 186,570 bp in length with a 37.6% G + C content. A total of 281 putative open reading frames (ORFs) and two tRNAs were found, where 150 ORFs encoded hypothetical proteins with unknown function. Comparative analysis showed that phiC120 shared high similarity at nucleotide and protein levels with coliphages RB69 and phiE142. Detailed phiC120 analysis revealed that ORF 94 encodes a putative depolymerase, meanwhile genes encoding factors associated with lysogeny, toxins, and antibiotic resistance were absent; however, ORF 95 encodes a putative protein with potential allergenic and pro-inflammatory properties, making needed further studies to guarantee the safety of phiC120 for human use. The characterization of phiC120 expands our knowledge about the biology of coliphages and provides novel insights supporting its potential for the development of phage-based applications to control unwanted bacteria.

scholarly journals Peptidoglycan sensing prevents quiescence and promotes quorum-independent growth of uropathogenic Escherichia coli

2019 ◽  
Author(s):  
Eric C. DiBiasio ◽  
Hilary J. Ranson ◽  
James R. Johnson ◽  
David C. Rowley ◽  
Paul S. Cohen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Structural Integrity ◽  
Recurrent Infection ◽  
Multidrug Resistant ◽  
Quiescent State ◽  
E Coli ◽  
Tract Infections ◽  
Patients Experience

AbstractThe layer of peptidoglycan surrounding bacteria provides structural integrity for the bacterial cell wall. Many organisms, including human cells and diverse bacteria, detect peptidoglycan fragments that are released as bacteria grow. Uropathogenic Escherichia coli (UPEC) strains are the leading cause of human urinary tract infections (UTIs) and many patients experience recurrent infection after successful antibiotic treatment. The source of recurrent infections may be persistent bacterial reservoirs in vivo that are in a quiescent state and, thus, are not susceptible to antibiotics. Here, we show that multiple UPEC strains require a quorum to proliferate in vitro with glucose as the sole carbon source; at low density, the bacteria remain viable but enter a quiescent, non-proliferative state. Of all clinical UPEC isolates tested to date, 35% (51/145) enter this quiescent state, including archetypal strains CFT073 (from classic endemic lineage ST73) and JJ1886 (from recently emerged, multidrug-resistant pandemic lineage ST131). We further show that quorum-dependent UPEC quiescence is prevented and reversed by small molecules, called proliferants, that stimulate growth, such as L-lysine, L-methionine, and peptidoglycan (PG) stem peptides, including an isolated PG pentapeptide from Staphylococcus aureus. Together, our results indicate that (i) uptake of L-lysine and (ii) PG peptide sensing by UPEC modulate the quorum-regulated decision to proliferate and further demonstrate that PG fragments are important for intra- and interspecies signaling in pathogenic E. coli.

scholarly journals Next generation sequencing and in vivo pathogenicity study of multidrug-resistance efflux pump genesoqxAB-encoding plasmids in Escherichia coli

2020 ◽  
Vol 2 (7A) ◽  
Author(s):  
Andes Lau ◽  
Huiluo Cao ◽  
Melissa Chun-Jian Liu ◽  
Man-Ki Tong ◽  
Kin-Hung Chow ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Hong Kong ◽  
Galleria Mellonella ◽  
Efflux Pump ◽  
Antibiotic Resistance Genes ◽  
Multidrug Resistant ◽  
E Coli ◽  
Pathogenic Factors ◽  
Health Deterioration

Background: Multidrug-resistant efflux pump genes oqxAB-encoding plasmids are wildly disseminated in livestock, and also identified in human samples. Giving the high presence in environment and multidrug-resistant nature of oqxAB, deeper understanding of oqxAB-encoding plasmids is necessary. Objective: To investigate the prevalence, virulence, and phylogenetic of oqxAB-encoding plasmids. Method: A total of 43 oqxAB carrying Escherichia coli were isolated from human and livestock from China and Hong Kong, these isolates were characterised by disc-diffusion susceptibility test and PCR. The 43 samples were sequenced using PacBio or Illumina platforms, and analysied with five oqxAB-encoding plasmid sequences extracted from Genbank. in vivo pathogenicity study performed by injecting E. coli J53 transconjugants containing oqxAB plasmid into Galleria mellonella larvae. Result: Among the 48 oqxAB-encoding plasmids, 27 were IncFII F18 plasmids, 12 F16 plasmids, six F33 plasmids, two F24 plasmids, and one F14 plasmid. Virulence regions in plasmids with same Inc group encoded similar set of virulence factors and antibiotic resistance genes. Co-existence of blaCTX-M, fosA3, and oqxAB genes was identified in all F33 plasmids and one F18 plasmid. in vivo pathogenicity study suggested oqxAB plasmids caused significant health deterioration in larvae but no significant increase in death. Conclusion: Our data shows similar sets of pathogenic factors are frequently co-carried by oqxAB plasmids of same Inc group, suggesting high correlation between plasmids identified from China and Hong Kong. Co-existence of fosA3, blaCTX-M, and oqxAB suggests resistance to most clinical antibiotics. in vivo test indicates oqxAB plasmid can increase pathogenicity of the host bacteria.

scholarly journals Conversion of Methylglyoxal to Acetol by Escherichia coli Aldo-Keto Reductases

2005 ◽  
Vol 187 (16) ◽  
pp. 5782-5789 ◽  
Author(s):  
Junsang Ko ◽  
Insook Kim ◽  
Seokho Yoo ◽  
Bumchan Min ◽  
Kyungmin Kim ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Biochemical Study ◽  
Cell Types ◽  
Open Reading Frames ◽  
Toxic Metabolite ◽  
E Coli ◽  
H Nmr ◽  
Crude Extracts

ABSTRACT Methylglyoxal (MG) is a toxic metabolite known to accumulate in various cell types. We detected in vivo conversion of MG to acetol in MG-accumulating Escherichia coli cells by use of 1H nuclear magnetic resonance (1H-NMR) spectroscopy. A search for homologs of the mammalian aldo-keto reductases (AKRs), which are known to exhibit activity to MG, revealed nine open reading frames from the E. coli genome. Based on both sequence similarities and preliminary characterization with 1H-NMR for crude extracts of the corresponding mutant strains, we chose five genes, yafB, yqhE, yeaE, yghZ, and yajO, for further study. Quantitative assessment of the metabolites produced in vitro from the crude extracts of these mutants and biochemical study with purified AKRs indicated that the yafB, yqhE, yeaE, and yghZ genes are involved in the conversion of MG to acetol in the presence of NADPH. When we assessed their in vivo catalytic activities by creating double mutants, all of these genes except for yqhE exhibited further sensitivities to MG in a glyoxalase-deficient strain. The results imply that the glutathione-independent detoxification of MG can occur through multiple pathways, consisting of yafB, yqhE, yeaE, and yghZ genes, leading to the generation of acetol.

scholarly journals Synergy between Florfenicol and Aminoglycosides against Multidrug-Resistant Escherichia coli Isolates from Livestock

Antibiotics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 185 ◽  
Author(s):  
Shukho Kim ◽  
Jung Hwa Woo ◽  
So Hyun Jun ◽  
Dong Chan Moon ◽  
Suk-Kyung Lim ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Synergistic Effect ◽  
Antimicrobial Agents ◽  
Alternative Therapy ◽  
Multidrug Resistant ◽  
Combination Regimen ◽  
E Coli ◽  
Effective Combination

The increasing prevalence of antimicrobial resistance and the laborious development of novel antimicrobial agents have limited the options for effective antimicrobial therapy. The combination of previously used antimicrobial agents represents an alternative therapy for multidrug-resistant (MDR) pathogens. The objective of this study was to investigate the synergistic effect of a florfenicol (FFL)-based combination with other antimicrobial agents against MDR Escherichia coli isolates from livestock using checkerboard assays and murine infection models. The FFL/amikacin (AMK) and FFL/gentamicin (GEN) combinations showed synergy against 10/11 and 6/11 MDR E. coli isolates in vitro, respectively. The combination of FFL with aminoglycosides (AMK or GEN) exhibited a better synergistic effect against MDR E. coli isolates than the cephalothin (CEF)/GEN or FFL/CEF combinations. The combination of FFL with AMK or GEN could reduce the emergence of resistant mutants in vitro. The FFL/AMK combination showed a higher survival rate of mice infected with MDR E. coli isolates than FFL or AMK alone. In summary, the combination of FFL with aminoglycosides (AMK or GEN) is highly effective against MDR E. coli isolates both in vitro and in vivo. Our findings may contribute to the discovery of an effective combination regimen against MDR E. coli infections in veterinary medicine.

scholarly journals Hydroxycinnamate (hca) Catabolic Genes from Acinetobacter sp. Strain ADP1 Are Repressed by HcaR and Are Induced by Hydroxycinnamoyl-Coenzyme A Thioesters

2003 ◽  
Vol 69 (9) ◽  
pp. 5398-5409 ◽  
Author(s):  
Donna Parke ◽  
L. Nicholas Ornston
Keyword(s):  
Escherichia Coli ◽  
Sequence Analysis ◽  
Genetic Background ◽  
Open Reading Frames ◽  
Aldehyde Dehydrogenases ◽  
E Coli ◽  
Catabolic Genes ◽  
Coa Thioesters ◽  
Reading Frames

ABSTRACT Hydroxycinnamates are plant products catabolized through the diphenol protocatechuate in the naturally transformable bacterium Acinetobacter sp. strain ADP1. Genes for protocatechuate catabolism are central to the dca-pca-qui-pob-hca chromosomal island, for which gene designations corresponding to catabolic function are dca (dicarboxylic acid), pca (protocatechuate), qui (quinate), pob (p-hydroxybenzoate), and hca (hydroxycinnamate). Acinetobacter hcaC had been cloned and shown to encode a hydroxycinnamate:coenzyme A (CoA) SH ligase that acts upon caffeate, p-coumarate, and ferulate, but genes for conversion of hydroxycinnamoyl-CoA to protocatechuate had not been characterized. In this investigation, DNA from pobS to an XbaI site 5.3 kb beyond hcaC was captured in the plasmid pZR8200 by a strategy that involved in vivo integration of a cloning vector near the hca region of the chromosome. pZR8200 enabled Escherichia coli to convert p-coumarate to protocatechuate in vivo. Sequence analysis of the newly cloned DNA identified five open reading frames designated hcaA, hcaB, hcaK, hcaR, and ORF1. An Acinetobacter strain with a knockout of HcaA, a homolog of hydroxycinnamoyl-CoA hydratase/lyases, was unable to grow at the expense of hydroxycinnamates, whereas a strain mutated in HcaB, homologous to aldehyde dehydrogenases, grew poorly with ferulate and caffeate but well with p-coumarate. A chromosomal fusion of lacZ to the hcaE gene was used to monitor expression of the hcaABCDE promoter. LacZ was induced over 100-fold by growth in the presence of caffeate, p-coumarate, or ferulate. The protein deduced to be encoded by hcaR shares 28% identity with the aligned E. coli repressor, MarR. A knockout of hcaR produced a constitutive phenotype, as assessed in the hcaE::lacZ-Kmr genetic background, revealing HcaR to be a repressor as well. Expression of hcaE::lacZ in strains with knockouts in hcaA, hcaB, or hcaC revealed unambiguously that hydroxycinnamoyl-CoA thioesters relieve repression of the hcaABCDE genes by HcaR.

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