scholarly journals Characterization of the Escherichia coli Virulent Myophage ST32

Viruses ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 616 ◽  
Author(s):  
Honghui Liu ◽  
Hany Geagea ◽  
Geneviève Rousseau ◽  
Simon Labrie ◽  
Denise Tremblay ◽  
...  

The virulent phage ST32 that infects the Escherichia coli strain ST130 was isolated from a wastewater sample in China and analyzed. Morphological observations showed that phage ST32 belongs to the Myoviridae family, as it has an icosahedral capsid and long contractile tail. Host range analysis showed that it exhibits a broad range of hosts including non-pathogenic and pathogenic E. coli strains. Interestingly, phage ST32 had a much larger burst size when amplified at 20 °C as compared to 30 °C or 37 °C. Its double-stranded DNA genome was sequenced and found to contain 53,092 bp with a GC content of 44.14%. Seventy-nine open reading frames (ORFs) were identified and annotated as well as a tRNA-Arg. Only nineteen ORFs were assigned putative functions. A phylogenetic tree using the large terminase subunit revealed a close relatedness with four unclassified Myoviridae phages. A comparative genomic analysis of these phages showed that the Enterobacteria phage phiEcoM-GJ1 is the closest relative to ST32 and shares the same new branch in the phylogenetic tree. Still, these two phages share only 47 of 79 ORFs with more than 90% identity. Phage ST32 has unique characteristics that make it a potential biological control agent under specific conditions.

2021 ◽  
Vol 10 (8) ◽  
Author(s):  
Jacob R. Elder ◽  
Yanhong Liu ◽  
Siddhartha Kanrar ◽  
Andrew Gehring ◽  
Aixia Xu ◽  
...  

ABSTRACT Escherichia coli strain FEX669 was isolated from retail ground chicken and shown to contain the extraintestinal pathogenic E. coli (ExPEC) virulence genes sfaD, focC, and iutA. Because this presumptive ExPEC strain was isolated from a retail food item and it was a weak biofilm former, it was characterized using whole-genome sequencing using the PacBio RS II platform. Genomic analysis showed that the FEX669 chromosome is 4,973,943 bp long, with a GC content of 50.47%, and is accompanied by a ColV plasmid that is 237,102 bp long, with a GC content of 50.49%.


2011 ◽  
Vol 78 (1) ◽  
pp. 58-69 ◽  
Author(s):  
Minjung Park ◽  
Ju-Hoon Lee ◽  
Hakdong Shin ◽  
Minsik Kim ◽  
Jeongjoon Choi ◽  
...  

ABSTRACTSalmonella entericaandEscherichia coliO157:H7 are major food-borne pathogens causing serious illness. Phage SFP10, which revealed effective infection of bothS. entericaandE. coliO157:H7, was isolated and characterized. SFP10 contains a 158-kb double-stranded DNA genome belonging to the Vi01 phage-like familyMyoviridae.In vitroadsorption assays showed that the adsorption constant rates to bothSalmonella entericaserovar Typhimurium andE. coliO157:H7 were 2.50 × 10−8ml/min and 1.91 × 10−8ml/min, respectively. One-step growth analysis revealed that SFP10 has a shorter latent period (25 min) and a larger burst size (>200 PFU) than ordinaryMyoviridaephages, suggesting effective host infection and lytic activity. However, differential development of resistance to SFP10 inS.Typhimurium andE. coliO157:H7 was observed; bacteriophage-insensitive mutant (BIM) frequencies of 1.19 × 10−2CFU/ml forS.Typhimurium and 4.58 × 10−5CFU/ml forE. coliO157:H7 were found, indicating that SFP10 should be active and stable for control ofE. coliO157:H7 with minimal emergence of SFP10-resistant pathogens but may not be forS.Typhimurium. Specific mutation ofrfaLinS.Typhimurium andE. coliO157:H7 revealed the O antigen as an SFP10 receptor for both bacteria. Genome sequence analysis of SFP10 and its comparative analysis with homologousSalmonellaVi01 andShigellaphiSboM-AG3 phages revealed that their tail fiber and tail spike genes share low sequence identity, implying that the genes are major host specificity determinants. This is the first report identifying specific infection and inhibition ofSalmonellaTyphimurium andE. coliO157:H7 by a single bacteriophage.


2013 ◽  
Vol 80 (2) ◽  
pp. 515-524 ◽  
Author(s):  
Hyun Sung Lee ◽  
Slae Choi ◽  
Hakdong Shin ◽  
Ju-Hoon Lee ◽  
Sang Ho Choi

ABSTRACTA novelVibrio vulnificus-infecting bacteriophage, SSP002, belonging to theSiphoviridaefamily, was isolated from the coastal area of the Yellow Sea of South Korea. Host range analysis revealed that the growth inhibition of phage SSP002 is relatively specific toV. vulnificusstrains from both clinical and environmental samples. In addition, a one-step growth curve analysis and a bacteriophage stability test revealed a latent period of 65 min, a burst size of 23 ± 2 PFU, as well as broad temperature (20°C to 60°C) and pH stability (pH 3 to 12) ranges. A Tn5random transposon mutation ofV. vulnificusand partial DNA sequencing of the inserted Tn5regions revealed that theflhA,flhB,fliF, andfleQmutants are resistant to SSP002 phage infection, suggesting that the flagellum may be the host receptor for infection. The subsequent construction of specific gene-inactivated mutants (flhA,flhB,fliF, andfleQ) and complementation experiments substantiated this. Previously, the genome of phage SSP002 was completely sequenced and analyzed. Comparative genomic analysis of phage SSP002 andVibrio parahaemolyticusphage vB_VpaS_MAR10 showed differences among their tail-related genes, supporting different host ranges at the species level, even though their genome sequences are highly similar. An additional mouse survival test showed that the administration of phage SSP002 at a multiplicity of infection of 1,000 significantly protects mice from infection byV. vulnificusfor up to 2 months, suggesting that this phage may be a good candidate for the development of biocontrol agents againstV. vulnificusinfection.


2021 ◽  
Vol 53 (4) ◽  
Author(s):  
Jean N. Hakizimana ◽  
Jean B. Ntirandekura ◽  
Clara Yona ◽  
Lionel Nyabongo ◽  
Gladson Kamwendo ◽  
...  

AbstractSeveral African swine fever (ASF) outbreaks in domestic pigs have been reported in Burundi and Malawi and whole-genome sequences of circulating outbreak viruses in these countries are limited. In the present study, complete genome sequences of ASF viruses (ASFV) that caused the 2018 outbreak in Burundi (BUR/18/Rutana) and the 2019 outbreak in Malawi (MAL/19/Karonga) were produced using Illumina next-generation sequencing (NGS) platform and compared with other previously described ASFV complete genomes. The complete nucleotide sequences of BUR/18/Rutana and MAL/19/Karonga were 176,564 and 183,325 base pairs long with GC content of 38.62 and 38.48%, respectively. The MAL/19/Karonga virus had a total of 186 open reading frames (ORFs) while the BUR/18/Rutana strain had 151 ORFs. After comparative genomic analysis, the MAL/19/Karonga virus showed greater than 99% nucleotide identity with other complete nucleotides sequences of p72 genotype II viruses previously described in Tanzania, Europe and Asia including the Georgia 2007/1 isolate. The Burundian ASFV BUR/18/Rutana exhibited 98.95 to 99.34% nucleotide identity with genotype X ASFV previously described in Kenya and in Democratic Republic of the Congo (DRC). The serotyping results classified the BUR/18/Rutana and MAL/19/Karonga ASFV strains in serogroups 7 and 8, respectively. The results of this study provide insight into the genetic structure and antigenic diversity of ASFV strains circulating in Burundi and Malawi. This is important in order to understand the transmission dynamics and genetic evolution of ASFV in eastern Africa, with an ultimate goal of designing an efficient risk management strategy against ASF transboundary spread.


2020 ◽  
Author(s):  
Jing Xu ◽  
Yu Gu ◽  
Xinyan Yu ◽  
Ruiyang Zhang ◽  
Xuesen Zhang ◽  
...  

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.


2019 ◽  
Vol 87 (10) ◽  
Author(s):  
Tracy H. Hazen ◽  
David A. Rasko

ABSTRACT Enteropathogenic Escherichia coli (EPEC) is a leading cause of moderate to severe diarrhea among young children in developing countries, and EPEC isolates can be subdivided into two groups. Typical EPEC (tEPEC) bacteria are characterized by the presence of both the locus of enterocyte effacement (LEE) and the plasmid-encoded bundle-forming pilus (BFP), which are involved in adherence and translocation of type III effectors into the host cells. Atypical EPEC (aEPEC) bacteria also contain the LEE but lack the BFP. In the current report, we describe the complete genome of outbreak-associated aEPEC isolate E110019, which carries four plasmids. Comparative genomic analysis demonstrated that the type III secreted effector EspT gene, an autotransporter gene, a hemolysin gene, and putative fimbrial genes are all carried on plasmids. Further investigation of 65 espT-containing E. coli genomes demonstrated that different espT alleles are associated with multiple plasmids that differ in their overall gene content from the E110019 espT-containing plasmid. EspT has been previously described with respect to its role in the ability of E110019 to invade host cells. While other type III secreted effectors of E. coli have been identified on insertion elements and prophages of the chromosome, we demonstrated in the current study that the espT gene is located on multiple unique plasmids. These findings highlight a role of plasmids in dissemination of a unique E. coli type III secreted effector that is involved in host invasion and severe diarrheal illness.


2020 ◽  
Vol 14 (6) ◽  
pp. e0008373 ◽  
Author(s):  
Rodrigo T. Hernandes ◽  
Tracy H. Hazen ◽  
Luís F. dos Santos ◽  
Taylor K. S. Richter ◽  
Jane M. Michalski ◽  
...  

2012 ◽  
Vol 78 (7) ◽  
pp. 2264-2271 ◽  
Author(s):  
Allan L. Delisle ◽  
Ming Guo ◽  
Natalia I. Chalmers ◽  
Gerard J. Barcak ◽  
Geneviève M. Rousseau ◽  
...  

ABSTRACTM102AD is the new designation for aStreptococcus mutansphage described in 1993 as phage M102. This change was necessitated by the genome analysis of anotherS. mutansphage named M102, which revealed differences from the genome sequence reported here. Additional host range analyses confirmed thatS. mutansphage M102AD infects only a few serotype c strains. Phage M102AD adsorbed very slowly to its host, and it cannot adsorb to serotype e and f strains ofS. mutans. M102AD adsorption was blocked by c-specific antiserum. Phage M102AD also adsorbed equally well to heat-treated and trypsin-treated cells, suggesting carbohydrate receptors. Saliva and polysaccharide production did not inhibit plaque formation. The genome of this siphophage consisted of a linear, double-stranded, 30,664-bp DNA molecule, with a GC content of 39.6%. Analysis of the genome extremities indicated the presence of a 3′-overhangcossite that was 11 nucleotides long. Bioinformatic analyses identified 40 open reading frames, all in the same orientation. No lysogeny-related genes were found, indicating that phage M102AD is strictly virulent. No obvious virulence factor gene candidates were found. Twelve proteins were identified in the virion structure by mass spectrometry. Comparative genomic analysis revealed a close relationship betweenS. mutansphages M102AD and M102 as well as withStreptococcus thermophilusphages. This study also highlights the importance of conducting research with biological materials obtained from recognized microbial collections.


2009 ◽  
Vol 55 (5) ◽  
pp. 587-598 ◽  
Author(s):  
Hailang Luo ◽  
Li Shen ◽  
Huaqun Yin ◽  
Qian Li ◽  
Qijiong Chen ◽  
...  

Acidithiobacillus ferrooxidans is an important microorganism used in biomining operations for metal recovery. Whole-genomic diversity analysis based on the oligonucleotide microarray was used to analyze the gene content of 12 strains of A. ferrooxidans purified from various mining areas in China. Among the 3100 open reading frames (ORFs) on the slides, 1235 ORFs were absent in at least 1 strain of bacteria and 1385 ORFs were conserved in all strains. The hybridization results showed that these strains were highly diverse from a genomic perspective. The hybridization results of 4 major functional gene categories, namely electron transport, carbon metabolism, extracellular polysaccharides, and detoxification, were analyzed. Based on the hybridization signals obtained, a phylogenetic tree was built to analyze the evolution of the 12 tested strains, which indicated that the geographic distribution was the main factor influencing the strain diversity of these strains. Based on the hybridization signals of genes associated with bioleaching, another phylogenetic tree showed an evolutionary relationship from which the co-relation between the clustering of specific genes and geochemistry could be observed. The results revealed that the main factor was geochemistry, among which the following 6 factors were the most important: pH, Mg, Cu, S, Fe, and Al.


Sign in / Sign up

Export Citation Format

Share Document