scholarly journals Biological characteristics and anti-biofilm activity of a lytic phage against vancomycin-resistant Enterococcus faecium

2021 ◽  
Author(s):  
Forough Goodarzi ◽  
Masoumeh Hallajzadeh ◽  
Mohammad Sholeh ◽  
Malihe Talebi ◽  
Vahid Pirhajati Mahabadi ◽  
...  
Keyword(s):  
Enterococcus Faecium ◽  
Burst Size ◽  
Biological Properties ◽  
Lytic Phage ◽  
Wide Range ◽  
One Step ◽  
Vancomycin Resistant ◽  
Hospital Sewage ◽  
Phage Growth ◽  
And Control

Background and Objectives: An important leading cause of the emergence of vancomycin-resistant enterococci, especially Enterococcus faecium, is the inefficiency of antibiotics in the elimination of drug-resistant pathogens. Consequently, the need for alternative treatments is more necessary than ever. Materials and Methods: A highly effective bacteriophage against vancomycin-resistant E. faecium called vB-EfmS-S2 was isolated from hospital sewage. The biological properties of phage S2 and its effect on biofilm structures were determined. Results: Phage S2 was specifically capable of lysing a wide range of clinical E. faecium isolates. According to Electron mi- croscopy observations, the phage S2 belonged to the Siphoviridea family. Suitable pH spectra for phage survival was 5-11, at which the phage showed 100% activity. The optimal temperature for phage growth was 30-45°C, with the highest growth at 37°C. Based on one-step growth curve results, the latent period of phage S2 was 14 min with a burst size of 200 PFU/ml. The phage S2 was also able to tolerate bile at concentrations of 1 and 2% and required Mg2+ for an effective infection cycle. Biofilms were significantly inhibited and disrupted in the presence of the phage. Conclusion: According to the results, phage S2 could potentially be an alternative for the elimination and control of vancomycin-resistant E. faecium biofilm.  

scholarly journals Isolation and Characterization of a Phage to Control Vancomycin Resistant Enterococcus faecium

2018 ◽  
Vol 13 (1) ◽  
pp. 553-560 ◽  
Author(s):  
Taskeen Raza ◽  
Saadia Andleeb ◽  
Sidra Rahmat Ullah ◽  
Muhsin Jamal ◽  
Khalid Mehmood ◽  
...  
Keyword(s):  
Enterococcus Faecium ◽  
Burst Size ◽  
High Specificity ◽  
Sewage Water ◽  
Control Agent ◽  
Lytic Bacteriophage ◽  
Potential Control ◽  
Isolation And Characterization ◽  
One Step ◽  
Vancomycin Resistant

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.

scholarly journals Characterization and complete genome sequence analysis of novel bacteriophage IME-EFm1 infecting Enterococcus faecium

2014 ◽  
Vol 95 (11) ◽  
pp. 2565-2575 ◽  
Author(s):  
Yahui Wang ◽  
Wei Wang ◽  
Yongqiang Lv ◽  
Wangliang Zheng ◽  
Zhiqiang Mi ◽  
...  
Keyword(s):  
Genome Sequence ◽  
Complete Genome Sequence ◽  
Enterococcus Faecium ◽  
Complete Genome ◽  
Therapeutic Agent ◽  
Burst Size ◽  
Antibiotic Resistance Gene ◽  
Amino Acid Sequences ◽  
Lysis Activity ◽  
Wide Range

We isolated and characterized a novel virulent bacteriophage, IME-EFm1, specifically infecting multidrug-resistant Enterococcus faecium. IME-EFm1 is morphologically similar to members of the family Siphoviridae. It was found capable of lysing a wide range of our E. faecium collections, including two strains resistant to vancomycin. One-step growth tests revealed the host lysis activity of phage IME-EFm1, with a latent time of 30 min and a large burst size of 116 p.f.u. per cell. These biological characteristics suggested that IME-EFm1 has the potential to be used as a therapeutic agent. The complete genome of IME-EFm1 was 42 597 bp, and was linear, with terminally non-redundant dsDNA and a G+C content of 35.2 mol%. The termini of the phage genome were determined with next-generation sequencing and were further confirmed by nuclease digestion analysis. To our knowledge, this is the first report of a complete genome sequence of a bacteriophage infecting E. faecium. IME-EFm1 exhibited a low similarity to other phages in terms of genome organization and structural protein amino acid sequences. The coding region corresponded to 90.7 % of the genome; 70 putative ORFs were deduced and, of these, 29 could be functionally identified based on their homology to previously characterized proteins. A predicted metallo-β-lactamase gene was detected in the genome sequence. The identification of an antibiotic resistance gene emphasizes the necessity for complete genome sequencing of a phage to ensure it is free of any undesirable genes before use as a therapeutic agent against bacterial pathogens.

scholarly journals Bacteriophage φYeO3-12, Specific forYersinia enterocolitica Serotype O:3, Is Related to Coliphages T3 and T7

2000 ◽  
Vol 182 (18) ◽  
pp. 5114-5120 ◽  
Author(s):  
Maria Pajunen ◽  
Saija Kiljunen ◽  
Mikael Skurnik
Keyword(s):  
Physical Map ◽  
Burst Size ◽  
Restriction Enzymes ◽  
Structural Proteins ◽  
Close Relative ◽  
Lytic Phage ◽  
Serotype O ◽  
One Step ◽  
Phage Capsid ◽  
Phage Receptor

Bacteriophage φYeO3-12 is a lytic phage of Yersinia enterocolitica serotype O:3. The phage receptor is the lipopolysaccharide O chain of this serotype that consists of the rare sugar 6-deoxy-l-altropyranose. A one-step growth curve of φYeO3-12 revealed eclipse and latent periods of 15 and 25 min, respectively, with a burst size of about 120 PFU per infected cell. In electron microscopy φYeO3-12 virions showed pentagonal outlines, indicating their icosahedral nature. The phage capsid was shown to be composed of at least 10 structural proteins, of which a protein of 43 kDa was predominant. N-terminal sequences of three structural proteins were determined, two of them showing strong homology to structural proteins of coliphages T3 and T7. The phage genome was found to consist of a double-stranded DNA molecule of 40 kb without cohesive ends. A physical map of the phage DNA was constructed using five restriction enzymes. The phage infection could be effectively neutralized using serum from a rabbit immunized with whole φYeO3-12 particles. The antiserum also neutralized T3 infection, although not as efficiently as that of φYeO3-12. φYeO3-12 was found to share, in addition to the N-terminal sequence homology, several common features with T3, including morphology and nonsubjectibility to F exclusion. The evidence conclusively indicated that φYeO3-12 is the first close relative of phage T3 to be described.

Control of Transmission of Vancomycin-Resistant Enterococcus faecium in a Long-Term–Care Facility

1999 ◽  
Vol 20 (05) ◽  
pp. 312-317 ◽  
Author(s):  
Maxine Armstrong-Evans ◽  
Margaret Litt ◽  
Margaret A. McArthur ◽  
Barbara Willey ◽  
Darlene Cann ◽  
...  
Keyword(s):  
Enterococcus Faecium ◽  
Long Term Care ◽  
Care Facility ◽  
Control Measures ◽  
Term Care ◽  
Long Term Care Facility ◽  
Rectal Swabs ◽  
Vancomycin Resistant ◽  
And Control

AbstractObjectives:To describe the investigation and control of transmission of vancomycin-resistant enterococci (VRE) in a residential long-term-care (LTC) setting.Outbreak Investigation:A strain of vancomycin-resistantEnterococcus faeciumnot previously isolated in Ontario colonized five residents of a 254-bed LTC facility in Toronto. The index case was identified when VRE was isolated from a urine culture taken after admission to a local hospital. Screening of rectal swabs from all 235 residents identified four others who were colonized with the same strain ofE faecium.Control Measures:Colonized residents were cohorted. VRE precautions were established as follows: gown and gloves for resident contact, restriction of contact between colonized and noncolonized residents, no sharing of personal equipment, and daily double-cleaning of residents' rooms and wheelchairs.Outcome:Two colonized residents died of causes unrelated to VRE. Although bacitracin therapy (75,000 units four times a day X 14 days) failed to eradicate carriage in two of three surviving residents, both cleared their carriage within 7 weeks. Repeat rectal swabs from 224 residents (91%) 2 months after isolation precautions were discontinued and from 125 residents (51%) 9 months later identified no new cases. Total cost of investigation and control was $12,061 (Canadian).Conclusion:VRE may be transmitted in LTC facilities, and colonized LTC residents could become important VRE reservoirs. Control of VRE transmission in LTC facilities can be achieved even with limited resources.

Isolation, Characterization, and Application in Poultry Product of a Specific Salmonella Bacteriophage S55

2021 ◽  
Author(s):  
Haojie Ge ◽  
Yanping Xu ◽  
Kai Zhang ◽  
Shuxuan Zhang ◽  
Maozhi Hu ◽  
...  
Keyword(s):  
Prevention And Control ◽  
Burst Size ◽  
Gc Content ◽  
Skin Surface ◽  
Open Reading Frames ◽  
Lytic Phage ◽  
Trna Genes ◽  
Host Bacterium ◽  
Salmonella Pullorum ◽  
And Control

Salmonellosis occurs frequently worldwide, causing serious threats to public health safety. The abuse of antibiotics is increasing the antibiotic resistance in bacteria, thereby making the prevention and control of Salmonella more difficult. A phage can help control the spread of bacteria. In this study, S55, a lytic phage, was isolated from faecal samples obtained from poultry farms using Salmonella Pullorum ( S . Pullorum) as the host bacterium. This phage belongs to Siphoviridae and has a polyhedral head and a retraction-free tail. S55 showed a strong ability to lyse Salmonella serovars, such as S . Pullorum (58/60, 96.67%) and S . Enteritidis (97/104, 93.27%). One-step growth kinetics showed that the latent period was 10 min, burst period was 80 min and burst size was 40 pfu/cell. The optimal multiplicity of infection was 0.01, and the phage was able to survive at a pH of 4–11 and temperature of 40°C–60°C for 60 min. Complete genome sequence analysis revealed that the S55 genome length is 42,781 bp (GC content, 50.28%) and it contains 58 open reading frames (ORF), including 25 ORFs with known or assumed functions, without tRNA genes. Moreover, S55 does not carry genes that encode virulence or resistance factors. At different temperatures (4°C or 25°C), S55 was found to lower the populations of S . Pullorum and S . Enteritidis on chicken skin surface. Its bacteriostatic effect at 4°C was higher than that at 25°C. In conclusion, S55 can be considered a promising biological agent for the prevention and control of Salmonella .

scholarly journals Characterization of Bacteriophage against Enterococcus faecium Resistant to Vancomycin Isolated from Chicken Skin

2019 ◽  
pp. 1-14
Author(s):  
Hazzierah Syaffieqah An Nadiah Azlan ◽  
Muhajir Hamid ◽  
Adelene Ai-Lian Song
Keyword(s):  
Latent Period ◽  
Growth Kinetics ◽  
Enterococcus Faecium ◽  
Burst Size ◽  
Single Step ◽  
Vancomycin Resistant Enterococcus ◽  
Chicken Skin ◽  
Step Growth ◽  
Vancomycin Resistant ◽  
Faecium Strain

Aims: To characterize bacteriophages with strong in vitro lytic activity against vancomycin resistant Enterococcus faecium before testing on the chicken skin for their efficacy. Study Design: An experimental was carried out to characterize two isolated bacteriophages against Enterococcus faecium and test for their efficacy on chicken skin. Study Place: The study was carried out in Laboratory of Vaccine and Immunotherapeutics, Institue of Bioscience, Universiti Putra Malaysia in Selangor, which is the most populous state in Malaysia. Methodology: Two host specific lytic phages against vancomycin resistant Enterococcus faecium strain FM8, designated as FM8-P1 and FM8-P2 were physiological characterized. This includes determination of their adsorption rate, multiplicity of infection, and single step growth kinetics. The optimum pH and temperature for both bacteriophages activity were also determined before tested on chicken skin at 4°C and 25°C, which represent chiller and room temperature in poultry production line. Results: Based on the result of single-step growth kinetics, the latent period of FM8-P1 was 35 min with a burst size of 460 particles per infected cells, while FM8-P2 has a shorter latent period (20 min) but a smaller burst size of 60 particles. The highest adsorption rate for FM8-P1 was 83% and FM8-P2 was 90% at 2 min and 4 min respectively. Both bacteriophages also exihibited a wide range of pH and temperature for their activity. Conclusion: The specificity, lytic activity and stability of FM8-P1 and FM8-P2 emphasized their potential in effectively eliminating the vancomycin resistant Enterococcus faecium strain FM8. However, further works are required to validate their in situ reliability.

scholarly journals Isolation and Characterization of Six Vibrio parahaemolyticus Lytic Bacteriophages From Seafood Samples

2021 ◽  
Vol 12 ◽  
Author(s):  
Chia Wanq Tan ◽  
Yaya Rukayadi ◽  
Hanan Hasan ◽  
Noor-Azira Abdul-Mutalib ◽  
Nuzul Noorahya Jambari ◽  
...  
Keyword(s):  
Vibrio Parahaemolyticus ◽  
Burst Size ◽  
Foodborne Pathogen ◽  
Biological Properties ◽  
Promising Alternative ◽  
Narrow Host Range ◽  
Isolation And Characterization ◽  
Wide Range ◽  
The Stability

Vibrio parahaemolyticus is a foodborne pathogen that is frequently isolated from a variety of seafood. To control this pathogenic Vibrio spp., the implementation of bacteriophages in aquaculture and food industries have shown a promising alternative to antibiotics. In this study, six bacteriophages isolated from the seafood samples demonstrated a narrow host range specificity that infecting only the V. parahaemolyticus strains. Morphological analysis revealed that bacteriophages Vp33, Vp22, Vp21, and Vp02 belong to the Podoviridae family, while bacteriophages Vp08 and Vp11 were categorized into the Siphoviridae family. All bacteriophages were composed of DNA genome and showed distinctive restriction fragment length polymorphism. The optimal MOI for bacteriophage propagation was determined to be 0.001 to 1. One-step growth curve revealed that the latent period ranged from 10 to 20 min, and the burst size of bacteriophage was approximately 17 to 51 PFU/cell. The influence of temperature and pH levels on the stability of bacteriophages showed that all bacteriophages were optimally stable over a wide range of temperatures and pH levels. In vitro lytic activity of all bacteriophages demonstrated to have a significant effect against V. parahaemolyticus. Besides, the application of a bacteriophage cocktail instead of a single bacteriophage suspension was observed to have a better efficiency to control the growth of V. parahaemolyticus. Results from this study provided a basic understanding of the physiological and biological properties of the isolated bacteriophages before it can be readily used as a biocontrol agent against the growth of V. parahaemolyticus.

scholarly journals CHARACTERIZATION OF T4 MUTANTS THAT PARTIALLY SUPPRESS THE INABILITY OF T4rII TO GROW IN LAMBDA LYSOGENS

Genetics ◽  
1976 ◽  
Vol 83 (3) ◽  
pp. 477-487
Author(s):  
Theodore Homyk ◽  
Angel Rodriguez ◽  
Jon Weil
Keyword(s):  
Burst Size ◽  
Personal Communication ◽  
Growth Cycle ◽  
Plaque Morphology ◽  
One Step ◽  
Step Growth ◽  
The One ◽  
Phage Growth ◽  
L1 And L2

ABSTRACT In the course of isolating viable T4 deletions that affect plaque morphology (Homyk and Weil 1974), two closely linked point mutants, sip1 and sip2, were obtained. They map between genes t and 52, cause a reduction in plaque size and burst size, and partially suppress the lethality of rII mutants for growth in lambda lysogens. These characteristics demonstrate that sip1 and sip2 are similar to mutants previously reported by Freedman and Brenner (1972). In addition, D. Hall (personal communication) has shown that sip1 and sip2 are similar to the mutant farP85, which affects the regulation of a number of early genes (Chace and Hall 1975).—Sip suppression of rII mutants can be demonstrated in one-step growth experiments, even when both rII genes are completely deleted. This indicates that sip mutants do not simply reduce the level of rII gene products required for growth in a lambda lysogen. Instead, they alter the growth cycle so as to partially circumvent the need for any rII products.—Mutations at two other sites, designated L1 and L2, reverse the poor phage growth caused by sip and, in the one case tested, reverse the rII-suppressing ability of sip.

Control of Endemic Glycopeptide-Resistant Enterococci

1996 ◽  
Vol 17 (5) ◽  
pp. 286-292 ◽  
Author(s):  
Louise M. Dembry ◽  
Keke Uzokwe ◽  
Marcus J. Zervos
Keyword(s):  
Enterococcus Faecalis ◽  
Enterococcus Faecium ◽  
Control Measures ◽  
Resistant Organism ◽  
Renal Unit ◽  
Vancomycin Resistant ◽  
Enterococcus Gallinarum ◽  
Low Prevalence ◽  
And Control ◽  
Community Teaching

AbstractObjective:To evaluate the epidemiology of, and control measures for, vancomycin-resistantEnterococcus(VRE) in a renal unit.Design:A 3-month, prospective, prevalence culture survey of patients on a 24-bed renal unit.Setting:A 975-bed community teaching hospital.Patients:Patients admitted to the renal unit over a 3-month period. Patients identified with VRE were each matched with four patients without VRE isolated over the study period.Interventions/Control Measures:Resistant-organism barrier precautions. To eradicate carriage of VRE, two patients with VRE stool colonization were treated with 5 days of oral doxycycline (100 mg twice per day) and rifampin (300 mg/day).Results:Seven patients with VRE (8 isolates) were identified. Five isolates wereEnterococcus faecium(vancomycin MIC=16 to 256 μg/mL), two wereEnterococcus faecalis(MICs=16 and 124 μg/mL), and one wasEnterococcus gallinarum(MIC=8.0 μg/mL). Eradication of carriage with VRE was accomplished in two patients treated with doxycycline and rifampin. In the final 30 days of the culture survey and at 9 months, there were no further patients with VRE identified.Conclusions:Resistant-organism precautions and elimination of patient carriage may be useful measures for controlling the spread of low-prevalence endemic vancomycin-resistantEnterococcus.

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