scholarly journals Isolation and Characterization of ΦGF1, a Morphotype C3 Bacteriophage that InfectsEscherichia coli

2019 ◽  
Author(s):  
Renzo Punil ◽  
Miguel Talledo ◽  
Mayra Arcondo ◽  
Katherine Suárez ◽  
Kattya Zumaeta

ABSTRACTIt has been isolated a lytic bacteriophage specific toEscherichia coli, which can infect at least one different bacterial group. Phage ФGF1 was isolated from a wastewater treatment plant. It is resistant to the effect of chloroform and is stable at 40 and 50 °C. In addition, it is stable in the range of pH 5-8. Its host range is wide, infecting even strains from another genus such asShigella. The one-step growth curve yielded a short latent period of 15 minutes and a burst size of 85 PFU per infected cell. Under the electron microscope, this phage presents the C3 morphotype, extremely rare among members of the Podoviridae family. Phage ФGF1 shows some characteristics that could be considered useful in biocontrol applications againstE. coli. Keywords: Bacteriophage,Escherichia coli, morphotype C3,Podoviridae.IMPORTANCEWastewater throughout the world is a heavy carrier of potential pathogens that live in their environment along with other biological agents, such as bacteriophages, which play a controlling role of the bacterial populations there, as in soil. The description of the diversity of such bacteriophages is of paramount importance since they could be used to intentionally reduce or remove those pathogens from that environment. Our work describes a bacteriophage that lives primarily in this type of water.

2017 ◽  
Vol 25 (3) ◽  
pp. 273 ◽  
Author(s):  
J. Zhao ◽  
L. He ◽  
L. Pan ◽  
Y. Liu ◽  
H. Yao ◽  
...  

Pathogenic <em>Escherichia coli</em> (<em>E. coli</em>) is severely threatening the rabbit industry in China, and the concern over antibiotic-resistant bacteria has given rise to an urgent need for antibiotic alternatives. In this study, a member (ZRP1) of the <em>Myoviridae</em> family was isolated from rabbit faeces using a strain of rabbit atypical enteropathogenic <em>E. coli</em> (ZR1) as host. The one-step growth curve indicated that the latent period was around 25 to 30 min and the burst size was 144±31 plaque-forming unit/cell. The rate of phage-resistant mutation was 7×10<sup>–5</sup>±4×10<sup>–5</sup>. When the bacteriophage input at the multiplicity of infection (MOI) was 0.1, 1 or 10, the growth of host <em>E. coli</em> in broth was inhibited for 5 h. A single intravenous injection of ZRP1 at MOI 0.1, 1 or 10 significantly prolonged the survival time of rabbits which simultaneously received a lethal dose of ZR1.


2011 ◽  
Vol 77 (18) ◽  
pp. 6630-6635 ◽  
Author(s):  
E. J. Battaglioli ◽  
G. A. Baisa ◽  
A. E. Weeks ◽  
R. A. Schroll ◽  
A. J. Hryckowian ◽  
...  

ABSTRACTThe traditional genetic procedure for random or site-specific mutagenesis inEscherichia coliK-12 involves mutagenesis, isolation of mutants, and transduction of the mutation into a clean genetic background. The transduction step reduces the likelihood of complications due to secondary mutations. Though well established, this protocol is not tenable for many pathogenicE. colistrains, such as uropathogenic strain CFT073, because it is resistant to known K-12 transducing bacteriophages, such as P1. CFT073 mutants generated via a technique such as lambda Red mutagenesis may contain unknown secondary mutations. Here we describe the isolation and characterization of transducing bacteriophages for CFT073. Seventy-seven phage isolates were acquired from effluent water samples collected from a wastewater treatment plant in Madison, WI. The phages were differentiated by a host sensitivity-typing scheme with a panel ofE. colistrains from the ECOR collection and clinical uropathogenic isolates. We found 49 unique phage isolates. These were then examined for their ability to transduce antibiotic resistance gene insertions at multiple loci between different mutant strains of CFT073. We identified 4 different phages capable of CFT073 generalized transduction. These phages also plaque on the model uropathogenicE. colistrains 536, UTI89, and NU14. The highest-efficiency transducing phage, ΦEB49, was further characterized by DNA sequence analysis, revealing a double-stranded genome 47,180 bp in length and showing similarity to other sequenced phages. When combined with a technique like lambda Red mutagenesis, the newly characterized transducing phages provide a significant development in the genetic tools available for the study of uropathogenicE. coli.


2011 ◽  
Vol 57 (12) ◽  
pp. 1042-1051 ◽  
Author(s):  
Osvaldo López-Cuevas ◽  
Nohelia Castro-del Campo ◽  
Josefina León-Félix ◽  
Arturo González-Robles ◽  
Cristóbal Chaidez

Four phages isolated from cattle and poultry feces were analyzed for their ability to lyse Salmonella serotypes and Escherichia coli O157:H7. The phage one-step growth curves, morphology, and genetic characteristics were determined. All phages showed a lytic effect on various Salmonella serotypes and E. coli O157:H7, which lysed at least 70% of the 234 strains tested. The phages had latent periods ranging from 10 to 15 min and generation times of 30 to 45 min, while burst size fluctuated between 154 and 426 PFU/cell. Phages morphology showed isometric and elongated heads and rigid contractile tails, consistent with morphology of the Myoviridae family. Phages’ DNA dendrograms showed a distinctive RFLP when digested by HindIII and EcoRV, and SDS–PAGE profile showed distinctive proteins expression as well. In vitro phage challenge showed a total reduction of E. coli O157:H7, Salmonella Typhimurium and Saintpaul counts at 2 h, whereas for Salmonella Montevideo a reduction and retardation growth, at a multiplicity of infection (MOI) of 100, was observed; however, under a MOI of 10 000, no viable cells were detected after 4 h. The wide host ranges of these phages suggested they could be used for simultaneous biocontrol of some Salmonella serotypes and E. coli O157:H7.


2021 ◽  
Author(s):  
Krishna Kumar Haridhasapavalan ◽  
Pradeep Kumar Sundaravadivelu ◽  
Anshuman Mohapatra ◽  
Neha Joshi ◽  
Nayan Jyoti Das ◽  
...  

AbstractTranscription factor HAND2 has a significant role in vascularization, angiogenesis, and cardiac neural crest development. Also, it is one of the key cardiac factors crucial for the enhanced derivation of functional and mature myocytes from non-myocyte cells. Here, we report the generation of the recombinant human HAND2 fusion protein from the heterologous system. First, we cloned the full-length human HAND2 gene (only protein-coding sequence) after codon optimization along with the fusion tags (for cell penetration, nuclear translocation, and affinity purification) into the expression vector. We then transformed and expressed it in Escherichia coli (E. coli) strain, BL21(DE3). Next, the effect (in terms of expression) of tagging of fusion tags with this recombinant protein at two different terminals was also investigated. Notably, using affinity chromatography, we established the one-step homogeneous purification of human recombinant HAND2 protein; and through circular dichroism spectroscopy, we established that this purified protein had retained its secondary structure. Furthermore, we show that this purified human protein could transduce the human cells and translocate to its nucleus. Prospectively, the purified recombinant HAND2 protein can potentially be a safe and effective molecular tool in the direct cardiac reprogramming process and other biological applications.


1990 ◽  
Vol 53 (11) ◽  
pp. 944-947 ◽  
Author(s):  
AMY B. RONNER ◽  
DEAN O. CLIVER

Enterohemorrhagic Escherichia coli serogroup 0157:H7 is harbored by cattle and causes bloody diarrhea and hemolytic uremic syndrome in persons who consume raw milk and under-cooked beef. Samples of manure from Wisconsin dairy farms were tested for the presence of E. coli 0157:H7 as well as for bacteriophages (coliphages) specific for this microorganism. No E. coli 0157:H7 bacteria were isolated from any of the 21 manure samples taken from 12 farms. Nineteen of 20 samples yielded “nonspecific” coliphages that produced plaques both on 0157:H7 and on other E. coli. Only one sample yielded a coliphage that plaqued on 14 strains of 0157:H7 but not on other E. coli. This coliphage, designated “AR1,” is tailed and ca. 187 nm long; it produces distinct plaques ca. 0.5 mm in diameter; single-step growth experiments showed a latent period of 20 to 25 min and a burst size of 34 progeny plaque-forming units (PFU). AR1 was also tested against other enterobacteria, including: Escherichia hermanii, four species of Salmonella, four types of Yersinia enterocolitica, and a strain of Shigella dysenteriae which produces an enteric toxin similar to that produced by E. coli 0157:H7. Of these enteric bacteria, only S. dysenteriae yielded plaques, which suggests that there is a relationship between production of this toxin and susceptibility to coliphage AR1. Coliphage AR1 may be useful in detecting or identifying E. coli 0157:H7 and possibly other bacteria producing the same toxin, from human stool, animal manure, and food samples.


Antibiotics ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 74 ◽  
Author(s):  
Yen-Te Liao ◽  
Alexandra Salvador ◽  
Leslie A. Harden ◽  
Fang Liu ◽  
Valerie M. Lavenburg ◽  
...  

Shiga toxin-producing Escherichia coli (STEC) O145 is one of the most prevalent non-O157 serogroups associated with foodborne outbreaks. Lytic phages are a potential alternative to antibiotics in combatting bacterial pathogens. In this study, we characterized a Siphoviridae phage lytic against STEC O145 strains as a novel antimicrobial agent. Escherichia phage vB_EcoS-Ro145clw (Ro145clw) was isolated and purified prior to physiological and genomic characterization. Then, in vitro antimicrobial activity against an outbreak strain, E. coli O145:H28, was evaluated. Ro145clw is a double-stranded DNA phage with a genome 42,031 bp in length. Of the 67 genes identified in the genome, 21 were annotated with functional proteins, none of which were stx genes. Ro145clw had a latent period of 21 min and a burst size of 192 phages per infected cell. The phage could sustain a wide range of pH (pH 3 to pH 10) and temperatures (−80 °C to −73 °C). Ro145clw was able to reduce E. coli O145:H28 in lysogeny broth by approximately 5 log at 37 °C in four hours. These findings indicate that the Ro145clw phage is a promising antimicrobial agent that can be used to control E. coli O145 in adverse pH and temperature conditions.


2018 ◽  
Vol 13 (1) ◽  
pp. 553-560 ◽  
Author(s):  
Taskeen Raza ◽  
Saadia Andleeb ◽  
Sidra Rahmat Ullah ◽  
Muhsin Jamal ◽  
Khalid Mehmood ◽  
...  

AbstractEnterococcus faecium, is an important nosocomial pathogen with increased incidence of multidrug resistance (MDR) – specifically Vancomycin resistance.E. faeciumconstitutes the normal microbiota of the human intestine as well as exists in the hospitals and sewage, thus making the microorganism difficult to eliminate. Phage therapy has gained attention for controlling bacterial MDR infections and contaminations. We have successfully isolated from waste water and characterized a lytic bacteriophage STH1 capable of targeting Vancomycin resistantEnterococcus faecium(VREF) with high specificity. The phage was isolated from sewage water of a hospital at district Dera Ismail Khan, Pakistan. Initial characterization showed that magnesium and calcium ions significantly increased phage adsorption to the host. One step growth experiment showed a latent period of 18 min with burst size of 334 virions per cell. Optimal temperature and pH of the phage was 37°C and 7.0, respectively. Phage application to host strain grown in milk and water (treated and untreated) showed that the phage efficiently controlled bacterial growth. The study suggests that the phage STH1 can serve as potential control agent forE. faeciuminfections in medical facilities and in other environmental contaminations.


2012 ◽  
Vol 65 (4) ◽  
pp. 589-595 ◽  
Author(s):  
A. Ouali ◽  
H. Jupsin ◽  
J. L. Vasel ◽  
L. Marouani ◽  
A. Ghrabi

Korba wastewater treatment plant is a conventional activated sludge followed by three maturation ponds (MP1, MP2, MP3) in series acting as a tertiary treatment. The first study of wastewater treatment plants showed that the effluent concentration of Escherichia coli and enterococci at the outlet of the (MP3) varies between 103 and 104CFU/100 ml. After the hydrodynamic study conducted by Rhodamine WT which showed short-circuiting in the MP1, two baffles were introduced in the first maturation pond (MP1) to improve the hydrodynamic and the sanitary performances. The second hydraulic study showed that the dispersion number ‘d’ was reduced from 1.45 to 0.43 by this engineering intervention and the Peclet number was raised from 0.69 to 2.32. The hydraulic retention time was increased by 14 h. Because of well-designed baffles, the removal efficiency of E. coli and enterococci was raised between 0.2 and 0.7 log units for the first maturation pond.


2021 ◽  
Vol 2021 (11) ◽  
pp. pdb.prot101212 ◽  
Author(s):  
Michael R. Green ◽  
Joseph Sambrook

This protocol describes a convenient method for the preparation, use, and storage of competent Escherichia coli. The reported transformation efficiency of this method is ∼5 × 107 transformants/µg of plasmid DNA.


1970 ◽  
Vol 18 ◽  
pp. 99-103 ◽  
Author(s):  
S Biswas ◽  
MAK Parvez ◽  
M Shafiquzzaman ◽  
S Nahar ◽  
MN Rahman

Context: Escherichia coli is shed in the feces of warm blooded animals and humans and thus potential for public health. Detection and characterization of E. coli in the ready-to-eat (RTE) foods concerns due to their presence indicates fecal contamination of the food.   Objective: To identify, characterize and RFLP pattern analysis of E. coli isolated from RTE foods vended in Islamic University campus, Kushtia.   Materials and Methods: Fifty samples from four types of consumed foods in six student halls of residence, some temporary restaurants of Islamic University, Kushtia were assessed for bacterial contamination by standard methods. Identification and characterization of E. coli isolates were performed using IMViC tests. Genomic DNA was used to perform RFLP pattern analysis.   Results: Thirty seven out of 50 (74%) examined samples of RTE foods had E. coli contamination. The highest number of E. coli was isolated from vegetable oriented RTE foods (90.90%) and fish, meat and cereals samples were also significantly E. coli positive. RFLP profiling of two E. coli isolates were observed.   Conclusion: The results of this study provide evidence that some RTE foods had unsatisfactory levels of contamination with E. coli. Thus street vended RTE food could be important potential vehicles for food-borne diseases. Molecular characterization may be exploited to identify food borne pathogen among different species.  Keywords: Ready-to-eat foods; Escherichia coli; RFLP pattern DOI: http://dx.doi.org/10.3329/jbs.v18i0.8783 JBS 2010; 18(0): 99-103


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