scholarly journals Complete Genome Sequence of vB_EcoP_SU7, a Podoviridae Coliphage with the Rare C3 Morphotype

2021 ◽  
Vol 9 (8) ◽  
pp. 1576
Author(s):  
Shazeeda Koonjan ◽  
Callum J. Cooper ◽  
Anders S. Nilsson
Keyword(s):  
Host Range ◽  
Burst Size ◽  
Phylogenetic Analyses ◽  
Treatment Plant ◽  
Latency Period ◽  
Enterotoxigenic Escherichia Coli ◽  
Therapeutic Success ◽  
Significant Similarity ◽  
Narrow Host Range ◽  
E Coli

Enterotoxigenic Escherichia coli (ETEC) strains are an important cause of bacterial diarrheal illness in humans and animals. Infections arising from ETEC could potentially be treated through the use of bacteriophage (phage) therapy, as phages encode for enzymes capable of bacterial cell lysis. vB_EcoP_SU7 was isolated from the Käppala wastewater treatment plant in Stockholm, Sweden, and propagated on an ETEC strain exhibiting the O:139 serovar. Transmission electron microscopy confirmed that vB_EcoP_SU7 belongs to the Podoviridae family and has the rare C3 morphotype of an elongated head. Bioinformatic analyses showed that the genome was 76,626 base pairs long and contained 35 genes with predicted functions. A total of 81 open reading frames encoding proteins with hypothetical function and two encoding proteins of no significant similarity were also found. A putative tRNA gene, which may aid in vB_EcoP_SU7’s translation, was also identified. Phylogenetic analyses showed that compared to other Podoviridae, vB_EcoP_SU7 is a rare Kuravirus and is closely related to E. coli phages with the uncommon C3 morphotype, such as ECBP2, EK010, vB_EcoP_EcoN5, and vB_EcoP_SU10. Phage vB_EcoP_SU7 has a narrow host range, infecting 11 out of the 137 E. coli strains tested, a latency period of 30 min, a burst size of 12 PFU/cell, and an adsorption rate of 8.78 × 10−9 mL/min five minutes post infection. With a limited host range and poor infection kinetics, it is unlikely that SU7 can be a standalone phage used for therapeutic purposes; rather, it must be used in combination with other phages for broad-spectrum therapeutic success.

scholarly journals Isolation of Polyvalent Bacteriophages by Sequential Multiple-Host Approaches

2015 ◽  
Vol 82 (3) ◽  
pp. 808-815 ◽  
Author(s):  
Pingfeng Yu ◽  
Jacques Mathieu ◽  
Mengyan Li ◽  
Zhaoyi Dai ◽  
Pedro J. J. Alvarez
Keyword(s):  
Host Range ◽  
Pseudomonas Syringae ◽  
Burst Size ◽  
Broad Host Range ◽  
Ecological Significance ◽  
Content Type ◽  
Narrow Host Range ◽  
Isolation Methods ◽  
Culture Independent ◽  
K 12

ABSTRACTMany studies on phage biology are based on isolation methods that may inadvertently select for narrow-host-range phages. Consequently, broad-host-range phages, whose ecological significance is largely unexplored, are consistently overlooked. To enhance research on such polyvalent phages, we developed two sequential multihost isolation methods and tested both culture-dependent and culture-independent phage libraries for broad infectivity. Lytic phages isolated from activated sludge were capable of interspecies or even interorder infectivity without a significant reduction in the efficiency of plating (0.45 to 1.15). Two polyvalent phages (PX1 of thePodoviridaefamily and PEf1 of theSiphoviridaefamily) were characterized in terms of adsorption rate (3.54 × 10−10to 8.53 × 10−10ml/min), latent time (40 to 55 min), and burst size (45 to 99 PFU/cell), using different hosts. These phages were enriched with a nonpathogenic host (Pseudomonas putidaF1 orEscherichia coliK-12) and subsequently used to infect model problematic bacteria. By using a multiplicity of infection of 10 in bacterial challenge tests, >60% lethality was observed forPseudomonas aeruginosarelative to uninfected controls. The corresponding lethality forPseudomonas syringaewas ∼50%. Overall, this work suggests that polyvalent phages may be readily isolated from the environment by using different sequential hosts, and this approach should facilitate the study of their ecological significance as well as enable novel applications.

scholarly journals Characterization of vB_StuS_MMDA13, a Newly Discovered Bacteriophage Infecting the Agar-Degrading Species Sphingomonas turrisvirgatae

Viruses ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 894
Author(s):  
Pasquale Marmo ◽  
Maria Cristina Thaller ◽  
Gustavo Di Lallo ◽  
Lucia Henrici De Angelis ◽  
Noemi Poerio ◽  
...  
Keyword(s):  
Burst Size ◽  
Latency Period ◽  
Biosynthetic Gene Cluster ◽  
Open Reading Frames ◽  
Lytic Bacteriophage ◽  
Coding Region ◽  
Narrow Host Range ◽  
Physiological Characterization ◽  
Wide Range ◽  
Valuable Compounds

Members of Sphingomonas genus have gained a notable interest for their use in a wide range of biotechnological applications, ranging from bioremediation to the production of valuable compounds of industrial interest. To date, knowledge on phages targeting Sphingomonas spp. are still scarce. Here, we describe and characterize a lytic bacteriophage, named vB_StuS_MMDA13, able to infect the Sphingomonas turrisvirgatae MCT13 type strain. Physiological characterization demonstrated that vB_StuS_MMDA13 has a narrow host range, a long latency period, a low burst size, and it is overall stable to both temperature and pH variations. The phage has a double-stranded DNA genome of 63,743 bp, with 89 open reading frames arranged in two opposite arms separated by a 1186 bp non-coding region and shows a very low global similarity to any other known phages. Interestingly, vB_StuS_MMDA13 is endowed with an original nucleotide modification biosynthetic gene cluster, which greatly differs from those of its most closely related phages of the Nipunavirus genus. vB_StuS_MMDA13 is the first characterized lytic bacteriophage of the Siphoviridae family infecting members of the Sphingomonas genus.

scholarly journals Isolation and Physiomorphological Characterization ofEscherichia coliO157:H7-Infecting Bacteriophages Recovered from Beef Cattle Operations

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Pushpinder Kaur Litt ◽  
Divya Jaroni
Keyword(s):  
Beef Cattle ◽  
Latent Period ◽  
Host Range ◽  
Cold Storage ◽  
Growth Parameters ◽  
Burst Size ◽  
Morphological Characteristics ◽  
Lytic Activity ◽  
E Coli ◽  
The Stability

Bacteriophages, recovered from beef cattle environment and specifically targetingEscherichia coliO157:H7, were examined for their physiological and morphological characteristics. Degree of bacterial lysis and host range of isolated bacteriophages was determined against 55 isolates ofE. coliO157:H7. Morphology of phages was examined under transmission electron microscope. Phage growth parameters, particularly rate of adsorption, rise period, latent period, and burst size were also determined. The stability of isolated phages was tested at acidic and alkaline pH, at high temperatures, and in cold storage. A total of 7 phages were isolated which showed lytic activity against 50 out of 55 isolates ofE. coliO157:H7. Based on the morphology, phages were classified into Myoviridae or Siphoviridae family. Phages had a rise period between 19 and 40 min, a short latent period between 12 and 30 min, and a large burst size (89–631 virions per infected cell), indicating high lytic activity. Phages remained stable for 24 h at a wide pH (1–11) and temperature range (40–60°C) and for 90 d in cold storage. Characterization of bacteriophages, with a diverse host range ofE. coliO157:H7, could aid in the development of effective biocontrol strategies for this pathogen in the food industry.

scholarly journals Wide Host Range and Strong Lytic Activity ofStaphylococcusaureusLytic Phage Stau2

2010 ◽  
Vol 77 (3) ◽  
pp. 756-761 ◽  
Author(s):  
Sue-Er Hsieh ◽  
Hsueh-Hsia Lo ◽  
Shui-Tu Chen ◽  
Mong-Chuan Lee ◽  
Yi-Hsiung Tseng
Keyword(s):  
Host Range ◽  
Burst Size ◽  
Latency Period ◽  
Multidrug Resistant ◽  
Coagulase Negative Staphylococci ◽  
Specific Phage ◽  
Double Stranded Dna ◽  
Lethal Infection ◽  
Complete Lysis ◽  
Cell Propagation

ABSTRACTIn searching for an alternative antibacterial agent against multidrug-resistantStaphylococcusaureus, we have isolated and characterized a lytic staphylophage, Stau2. It possesses a double-stranded DNA genome estimated to be about 134.5 kb and a morphology resembling that of members of the familyMyoviridae. With an estimated latency period of 25 min and a burst size of 100 PFU/infected cell, propagation of Stau2 in liquid culture gave a lysate of ca. 6 × 1010PFU/ml. It was stable at pH 5 to 13 in normal saline at room temperature for at least 4 weeks and at −85°C for more than 2 years, while 1 × 109out of 2 × 1012PFU/ml retained infectivity after 36 months at 4°C. Stau2 could lyse 80% of theS.aureusisolates (164/205) obtained from hospitals in Taiwan, with complete lysis of most of the isolates tested within 3 h; however, it was anS.aureus-specific phage because no lytic infection could be found in the coagulase-negative staphylococci tested. Its host range amongS.aureusisolates was wider than that of polyvalent phage K (47%), which can also lyse many other staphylococcal species. Experiments with mice demonstrated that Stau2 could provide 100% protection from lethal infection when a multiplicity of infection of 10 was administered immediately after a challenge withS.aureusS23. Considering these results, Stau2 could be considered at least as a candidate for topical phage therapy or an additive in the food industry.

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
Keyword(s):  
Escherichia Coli ◽  
Burst Size ◽  
Treatment Plant ◽  
Lytic Bacteriophage ◽  
Bacterial Populations ◽  
E Coli ◽  
Isolation And Characterization ◽  
Short Latent Period ◽  
One Step ◽  
The One

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.

scholarly journals Isolation and selection of Bacillus cereus specific phages from hospital wastewater

2020 ◽  
Vol 21 (7) ◽  
Author(s):  
Anwar Rovik ◽  
SAEFUDDIN ‘AZIZ ◽  
HENDRO PRAMONO
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Bacillus Cereus ◽  
Host Range ◽  
Latency Period ◽  
Pathogenic Bacterium ◽  
Citrobacter Freundii ◽  
Hospital Wastewater ◽  
Narrow Host Range ◽  
Selection Of

Abstract. Rovik A, ‘Aziz S, Pramono H. 2020. Isolation and selection of Bacillus cereus specific phages from hospital wastewater. Biodiversitas 21: 2871-2877. Bacillus cereus (B. cereus) is a pathogenic bacterium that frequently contaminates food by producing entero and emetic toxins. B. cereus has shown resistance to various antibiotics, especially β-lactam antibiotics. An alternative to control B. cereus contamination is the use of bacteriophages. This study aimed to isolate and screen B. cereus specific phages from hospital wastewater in Banyumas District. The research was conducted descriptively through isolation, purification, titer determination, host ranges, and adsorption rate determination. A total of 29 isolates of B. cereus-phages were isolated from hospital wastewater in Banyumas with various titers, ranged from 0.14-3.76 x 107 PFU.mL-1. Isolated phages could be grouped into two, narrow host range (14 phages) and broad activity spectra (15 phages) that infect both Gram-positive and negative bacteria i.e. B. subtilis, B. fragilis, B. licheniformis, Citrobacter freundii, Klebsiella pneumoniae, Salmonella thypi, and Escherichia coli. The infections had a latency period of 60-120 minutes. The decrease of culture absorbance value ranged from 0.06 to 0.41, while the control tended to increase by 0.39. The largest decreases were showed by phage isolates RSBMS-2 and RSBMT-1 with 0.41 and 0.37, respectively.

scholarly journals Characterization of vB_Kpn_F48, a Newly Discovered Lytic Bacteriophage for Klebsiella pneumoniae of Sequence Type 101

Viruses ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 482 ◽  
Author(s):  
Nagaia Ciacci ◽  
Marco D’Andrea ◽  
Pasquale Marmo ◽  
Elisa Demattè ◽  
Francesco Amisano ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Host Range ◽  
High Throughput Sequencing ◽  
Burst Size ◽  
Antibiotic Resistance Genes ◽  
Clinical Problem ◽  
Lytic Bacteriophage ◽  
Transmission Electron Microscopy Analysis ◽  
Narrow Host Range ◽  
Physiological Characterization

Resistance to carbapenems in Enterobacteriaceae, including Klebsiella pneumoniae, represents a major clinical problem given the lack of effective alternative antibiotics. Bacteriophages could provide a valuable tool to control the dissemination of antibiotic resistant isolates, for the decolonization of colonized individuals and for treatment purposes. In this work, we have characterized a lytic bacteriophage, named vB_Kpn_F48, specific for K. pneumoniae isolates belonging to clonal group 101. Phage vB_Kpn_F48 was classified as a member of Myoviridae, order Caudovirales, on the basis of transmission electron microscopy analysis. Physiological characterization demonstrated that vB_Kpn_F48 showed a narrow host range, a short latent period, a low burst size and it is highly stable to both temperature and pH variations. High throughput sequencing and bioinformatics analysis revealed that the phage is characterized by a 171 Kb dsDNA genome that lacks genes undesirable for a therapeutic perspective such integrases, antibiotic resistance genes and toxin encoding genes. Phylogenetic analysis suggests that vB_Kpn_F48 is a T4-like bacteriophage which belongs to a novel genus within the Tevenvirinae subfamily, which we tentatively named “F48virus”. Considering the narrow host range, the genomic features and overall physiological parameters phage vB_Kpn_F48 could be a promising candidate to be used alone or in cocktails for phage therapy applications.

scholarly journals Evolution of Pig Fecal Microbiota Composition and Diversity in Response to Enterotoxigenic Escherichia coli Infection and Colistin Treatment in Weaned Piglets

2021 ◽  
Vol 9 (7) ◽  
pp. 1459
Author(s):  
Mohamed Rhouma ◽  
Charlotte Braley ◽  
William Thériault ◽  
Alexandre Thibodeau ◽  
Sylvain Quessy ◽  
...  
Keyword(s):  
Oral Treatment ◽  
Fecal Microbiota ◽  
Enterotoxigenic Escherichia Coli ◽  
Rrna Gene ◽  
Weaned Piglets ◽  
E Coli ◽  
Escherichia Coli Infection ◽  
Pig Health ◽  
Microbiota Diversity ◽  
Sampling Times

The intestinal microbiota plays several important roles in pig health and growth. The aim of the current study was to characterize the changes in the fecal microbiota diversity and composition of weaned piglets following an oral challenge with an ETEC: F4 strain and/or a treatment with colistin sulfate (CS). Twenty-eight piglets were used in this experiment and were divided into four groups: challenged untreated, challenged treated, unchallenged treated, and unchallenged untreated. Rectal swab samples were collected at five sampling times throughout the study. Total genomic DNA was used to assess the fecal microbiota diversity and composition using the V4 region of the 16S rRNA gene. The relative abundance, the composition, and the community structure of piglet fecal microbiota was highly affected by the ETEC: F4 challenge throughout the experiment, while the oral treatment with CS, a narrow spectrum antibiotic, resulted in a significant decrease of E. coli/Shigella populations during the treatment period only. This study was the first to identify some gut microbiota subgroups (e.g., Streptococcus, Lachnospiraceae) that are associated with healthy piglets as compared to ETEC: F4 challenged animals. These key findings might contribute to the development of alternative strategies to reduce the use of antimicrobials in the control of post-weaning diarrhea in pigs.

scholarly journals Deletion of FaeG alleviated Enterotoxigenic Escherichia coli F4ac-induced apoptosis in the intestine

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pengpeng Xia ◽  
Yunping Wu ◽  
Siqi Lian ◽  
Guomei Quan ◽  
Yiting Wang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Clinical Symptoms ◽  
Mucosal Damage ◽  
Enterotoxigenic Escherichia Coli ◽  
Intestinal Epithelial ◽  
Antibody Microarray ◽  
E Coli ◽  
Fimbrial Subunit ◽  
Induced Apoptosis ◽  
Weaning Piglets

AbstractEnterotoxigenic Escherichia coli (ETEC) F4ac is a major constraint to the development of the pig industry, which is causing newborn and post-weaning piglets diarrhea. Previous studies proved that FaeG is the major fimbrial subunit of F4ac E. coli and efficient for bacterial adherence and receptor recognition. Here we show that the faeG deletion attenuates both the clinical symptoms of F4ac infection and the F4ac-induced intestinal mucosal damage in piglets. Antibody microarray analysis and the detection of mRNA expression using porcine neonatal jejunal IPEC-J2 cells also determined that the absence of FaeG subunit alleviated the F4ac promoted apoptosis in the intestinal epithelial cells. Thus, targeted depletion of FaeG is still beneficial for the prevention or treatment of F4ac infection.

scholarly journals Persulfate mediated solar photo-Fenton aiming at wastewater treatment plant effluent improvement at neutral PH: emerging contaminant removal, disinfection, and elimination of antibiotic-resistant bacteria

2021 ◽  
Author(s):  
Maria Clara V. M. Starling ◽  
Elizângela P. Costa ◽  
Felipe A. Souza ◽  
Elayne C. Machado ◽  
Juliana Calábria de Araujo ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Resistant Bacteria ◽  
Antibiotic Resistant Bacteria ◽  
Antibiotic Resistant ◽  
E Coli ◽  
Effluent Quality ◽  
Neutral Ph ◽  
Wastewater Treatment Plant Effluent

AbstractThis work investigated an innovative alternative to improve municipal wastewater treatment plant effluent (MWWTP effluent) quality aiming at the removal of contaminants of emerging concern (caffeine, carbendazim, and losartan potassium), and antibiotic-resistant bacteria (ARB), as well as disinfection (E. coli). Persulfate was used as an alternative oxidant in the solar photo-Fenton process (solar/Fe/S2O82−) due to its greater stability in the presence of matrix components. The efficiency of solar/Fe/S2O82− at neutral pH using intermittent iron additions is unprecedented in the literature. At first, solar/Fe/S2O82− was performed in a solar simulator (30 W m−2) leading to more than 60% removal of CECs, and the intermittent iron addition strategy was proved effective. Then, solar/Fe/S2O82− and solar/Fe/H2O2 were compared in semi-pilot scale in a raceway pond reactor (RPR) and a cost analysis was performed. Solar/Fe/S2O82− showed higher efficiencies of removal of target CECs (55%), E. coli (3 log units), and ARB (3 to 4 log units) within 1.9 kJ L−1 of accumulated irradiation compared to solar/Fe/H2O2 (CECs, 49%; E. coli, 2 log units; ARB, 1 to 3 log units in 2.5 kJ L−1). None of the treatments generated acute toxicity upon Allivibrio fischeri. Lower total cost was obtained using S2O82− (0.6 € m−3) compared to H2O2 (1.2 € m−3). Therefore, the iron intermittent addition aligned to the use of persulfate is suitable for MWWTP effluent quality improvement at neutral pH.

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