scholarly journals Two Phages, phiIPLA-RODI and phiIPLA-C1C, Lyse Mono- and Dual-Species Staphylococcal Biofilms

2015 ◽  
Vol 81 (10) ◽  
pp. 3336-3348 ◽  
Author(s):  
Diana Gutiérrez ◽  
Dieter Vandenheuvel ◽  
Beatriz Martínez ◽  
Ana Rodríguez ◽  
Rob Lavigne ◽  
...  
Keyword(s):  
Phage Therapy ◽  
Gene Organization ◽  
Open Reading Frames ◽  
Group I Introns ◽  
High Similarity ◽  
Content Type ◽  
Staphylococcal Infections ◽  
Group I ◽  
Genes Encoding ◽  
Reading Frames

ABSTRACTPhage therapy is a promising option for fighting against staphylococcal infections. Two lytic phages, vB_SauM_phiIPLA-RODI (phiIPLA-RODI) and vB_SepM_phiIPLA-C1C (phiIPLA-C1C), belonging to theMyoviridaefamily and exhibiting wide host ranges, were characterized in this study. The complete genome sequences comprised 142,348 bp and 140,961 bp and contained 213 and 203 open reading frames, respectively. The gene organization was typical ofSpounavirinaemembers, with long direct terminal repeats (LTRs), genes grouped into modules not clearly separated from each other, and several group I introns. In addition, four genes encoding tRNAs were identified in phiIPLA-RODI. Comparative DNA sequence analysis showed high similarities with two phages, GH15 and 676Z, belonging to theTwort-like virusgenus (nucleotide identities of >84%); for phiIPLA-C1C, a high similarity with phage phiIBB-SEP1 was observed (identity of 80%). Challenge assays of phages phiIPLA-RODI and phiIPLA-C1C against planktonic staphylococcal cells confirmed their lytic ability, as they were able to remove 5 log units in 8 h. Exposure of biofilms to phages phiIPLA-RODI and phiIPLA-C1C reduced the amount of adhered bacteria to about 2 log units in both monospecies and dual-species biofilms, but phiIPLA-RODI turned out to be as effective as the mixture of both phages. Moreover, the frequencies of bacteriophage-insensitive mutants (BIMs) ofStaphylococcus aureusandS. epidermidiswith resistance to phiIPLA-RODI and phiIPLA-C1C were low, at 4.05 × 10−7± 2.34 × 10−9and 1.1 × 10−7± 2.08 × 10−9, respectively. Overall, a generally reduced fitness in the absence of phages was observed for BIMs, which showed a restored phage-sensitive phenotype in a few generations. These results confirm that lytic bacteriophages can be efficient biofilm-disrupting agents, supporting their potential as antimicrobials against staphylococcal infections.

scholarly journals Tn6350, a Novel Transposon Carrying Pyocin S8 Genes Encoding a Bacteriocin with Activity against Carbapenemase-Producing Pseudomonas aeruginosa

2017 ◽  
Vol 61 (5) ◽  
Author(s):  
Helena Turano ◽  
Fernando Gomes ◽  
Gesiele A. Barros-Carvalho ◽  
Ralf Lopes ◽  
Louise Cerdeira ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Type A ◽  
Sequence Type ◽  
Open Reading Frames ◽  
Hypothetical Proteins ◽  
Immunity Protein ◽  
Content Type ◽  
Commensal Strain ◽  
Genes Encoding ◽  
Reading Frames

ABSTRACT A novel transposon belonging to the Tn3-like family was identified on the chromosome of a commensal strain of Pseudomonas aeruginosa sequence type 2343 (ET02). Tn6350 is 7,367 bp long and harbors eight open reading frames (ORFs), an ATPase (IS481 family), a transposase (DDE catalytic type), a Tn3 resolvase, three hypothetical proteins, and genes encoding the new pyocin S8 with its immunity protein. We show that pyocin S8 displays activity against carbapenemase-producing P. aeruginosa, including IMP-1, SPM-1, VIM-1, GES-5, and KPC-2 producers.

scholarly journals The Concerted Action of Two B3-Like Prophage Genes Excludes Superinfecting Bacteriophages by Blocking DNA Entry into Pseudomonas aeruginosa

2020 ◽  
Vol 94 (15) ◽  
Author(s):  
Marco Antonio Carballo-Ontiveros ◽  
Adrián Cazares ◽  
Pablo Vinuesa ◽  
Luis Kameyama ◽  
Gabriel Guarneros
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Pathogenic Bacteria ◽  
Phage Therapy ◽  
Alternative Therapy ◽  
Multidrug Resistant ◽  
Open Reading Frames ◽  
Resistant Bacteria ◽  
Content Type ◽  
Secondary Infections ◽  
Genes Encoding

ABSTRACT In this study, we describe seven vegetative phage genomes homologous to the historic phage B3 that infect Pseudomonas aeruginosa. Like other phage groups, the B3-like group contains conserved (core) and variable (accessory) open reading frames (ORFs) grouped at fixed regions in their genomes; however, in either case, many ORFs remain without assigned functions. We constructed lysogens of the seven B3-like phages in strain Ps33 of P. aeruginosa, a novel clinical isolate, and assayed the exclusion phenotype against a variety of temperate and virulent superinfecting phages. In addition to the classic exclusion conferred by the phage immunity repressor, the phenotype observed in B3-like lysogens suggested the presence of other exclusion genes. We set out to identify the genes responsible for this exclusion phenotype. Phage Ps56 was chosen as the study subject since it excluded numerous temperate and virulent phages. Restriction of the Ps56 genome, cloning of several fragments, and resection of the fragments that retained the exclusion phenotype allowed us to identify two core ORFs, so far without any assigned function, as responsible for a type of exclusion. Neither gene expressed separately from plasmids showed activity, but the concurrent expression of both ORFs is needed for exclusion. Our data suggest that phage adsorption occurs but that phage genome translocation to the host’s cytoplasm is defective. To our knowledge, this is the first report on this type of exclusion mediated by a prophage in P. aeruginosa. IMPORTANCE Pseudomonas aeruginosa is a Gram-negative bacterium frequently isolated from infected immunocompromised patients, and the strains are resistant to a broad spectrum of antibiotics. Recently, the use of phages has been proposed as an alternative therapy against multidrug-resistant bacteria. However, this approach may present various hurdles. This work addresses the problem that pathogenic bacteria may be lysogenized by phages carrying genes encoding resistance against secondary infections, such as those used in phage therapy. Discovering phage genes that exclude superinfecting phages not only assigns novel functions to orphan genes in databases but also provides insight into selection of the proper phages for use in phage therapy.

scholarly journals Two group I introns with long internal open reading frames in the chloroplastpsbAgene ofChlamydomonas moewusii

1989 ◽  
Vol 17 (10) ◽  
pp. 3875-3887 ◽  
Author(s):  
Monique Turmel ◽  
Jean Boulanger ◽  
Claude Lemieux
Keyword(s):  
Open Reading Frames ◽  
Group I Introns ◽  
Group I ◽  
Reading Frames

scholarly journals The tet39 Determinant and the msrE-mphE Genes in Acinetobacter Plasmids Are Each Part of Discrete Modules Flanked by Inversely Oriented pdif (XerC-XerD) Sites

2017 ◽  
Vol 61 (8) ◽  
Author(s):  
Grace A. Blackwell ◽  
Ruth M. Hall
Keyword(s):  
Insertion Sequence ◽  
Insertion Site ◽  
Tetracycline Resistance ◽  
Open Reading Frames ◽  
Gene Encoding ◽  
Content Type ◽  
System A ◽  
Genes Encoding ◽  
Putative Toxin ◽  
Reading Frames

ABSTRACT The tet39 tetracycline resistance determinant and the macrolide resistance genes msrE and mphE were found in an 18.2-kb plasmid, pS30-1, recovered from a global clone 2 (GC2) Acinetobacter baumannii isolate from Singapore, that conferred resistance to tetracycline and erythromycin. pS30-1 also contains mobA and mobC genes encoding MOBQ family proteins, but attempts to mobilize pS30-1 utilizing a coresident conjugative repAci6 plasmid were unsuccessful. Eight pdif sites, consisting of inversely oriented binding sites for the XerC and XerD recombinases separated by 6 bp, were detected in pS30-1. The tet39 determinant and the msrE-mphE gene pair are each surrounded by two pdif sites in inverse orientation. Identical regions in different contexts and many previously unnoticed pdif sites were found in a number of different plasmids in GenBank, showing that the tet39 and msrE-mphE dif modules are mobile. A putative toxin/antitoxin system, a gene encoding a serine recombinase, and open reading frames of unknown function were also part of dif modules in pS30-1. In general, modules with internal XerC or XerD sites alternate. Two copies of ISAjo2-1 (94% identical to ISAjo2) in pS30-1 were inserted 5 bp from a XerC site, and this appears to be the preferred insertion site for this insertion sequence (IS) group. Apparently, Acinetobacter plasmids exploit the Acinetobacter XerC-XerD recombinases to mobilize DNA units containing resistance and other genes, via an uncharacterized mechanism. The tet39 and msrE-mphE dif modules add to the oxa24 module and the oxa58 module redefined here, bringing the total of resistance gene-containing dif modules in Acinetobacter plasmids to four.

scholarly journals Characterization of a Novel Panton-Valentine Leukocidin (PVL)-Encoding Staphylococcal Phage and Its Naturally PVL-Lacking Variant

2013 ◽  
Vol 79 (8) ◽  
pp. 2828-2832 ◽  
Author(s):  
Lynn El Haddad ◽  
Sylvain Moineau
Keyword(s):  
Raw Milk ◽  
Open Reading Frames ◽  
Direct Repeats ◽  
Content Type ◽  
Genes Encoding ◽  
Tail Protein ◽  
Reading Frames ◽  
Panton Valentine Leukocidin ◽  
Valentine Leukocidin

ABSTRACTA new siphophage (LH1) was isolated from raw milk using aStaphylococcus aureusST352 host. Its genome (46,048 bp, 57 open reading frames) includes the two genes encoding Panton-Valentine leukocidin (PVL), a virulence factor usually harbored byS. aureusprophages. Nine structural proteins were identified, including a tail protein generated through a +1 frameshift. A phage lytic mutant was isolated, and its analysis revealed the deletion of genes coding for the PVL and an integrase. The deletion likely occurred through recombination between direct repeats.

scholarly journals vanO, a New Glycopeptide Resistance Operon in Environmental Rhodococcus equi Isolates

2013 ◽  
Vol 58 (3) ◽  
pp. 1768-1770 ◽  
Author(s):  
Dereje Dadi Gudeta ◽  
Arshnee Moodley ◽  
Valeria Bortolaia ◽  
Luca Guardabassi
Keyword(s):  
Unknown Function ◽  
Regulatory System ◽  
Rhodococcus Equi ◽  
Gene Organization ◽  
Open Reading Frames ◽  
Glycopeptide Resistance ◽  
Content Type ◽  
Clinical Interest ◽  
Direction Opposite ◽  
Reading Frames

ABSTRACTWe describe here the sequence and gene organization of a new glycopeptide resistance operon (vanO) inRhodococcus equifrom soil. ThevanOoperon has low homology to enterococcalvanoperons and harbors avanHOXcluster transcribed in the direction opposite that of thevanS-vanRregulatory system and composed of three open reading frames with unknown function. This finding has clinical interest, since glycopeptides are used to treatR. equiinfections and resistance has been reported in clinical isolates.

scholarly journals Nucleolar introns fromPhysarum flavicomumcontain insertion elements that may explain how mobile group I introns gained their open reading frames

1994 ◽  
Vol 22 (22) ◽  
pp. 4553-4559 ◽  
Author(s):  
Anna Vader ◽  
Jørund Naess ◽  
Kari Haugli ◽  
Finn Haugli ◽  
Steinar Johansen
Keyword(s):  
Open Reading Frames ◽  
Group I Introns ◽  
Group I ◽  
Insertion Elements ◽  
Reading Frames

scholarly journals Characterization of Bacteriophages Cp1 and Cp2, the Strain-Typing Agents for Xanthomonas axonopodis pv. citri

2013 ◽  
Vol 80 (1) ◽  
pp. 77-85 ◽  
Author(s):  
Abdelmonim Ali Ahmad ◽  
Megumi Ogawa ◽  
Takeru Kawasaki ◽  
Makoto Fujie ◽  
Takashi Yamada
Keyword(s):  
Genomic Sequence ◽  
Genomic Analysis ◽  
Citrus Canker ◽  
Open Reading Frames ◽  
Class Iii ◽  
Content Type ◽  
Xanthomonas Axonopodis ◽  
Group I ◽  
Initial Stage ◽  
Reading Frames

ABSTRACTThe strains ofXanthomonas axonopodispv. citri, the causative agent of citrus canker, are historically classified based on bacteriophage (phage) sensitivity. Nearly allX. axonopodispv. citri strains isolated from different regions in Japan are lysed by either phage Cp1 or Cp2; Cp1-sensitive (Cp1s) strains have been observed to be resistant to Cp2 (Cp2r) andvice versa. In this study, genomic and molecular characterization was performed for the typing agents Cp1 and Cp2. Morphologically, Cp1 belongs to theSiphoviridae. Genomic analysis revealed that its genome comprises 43,870-bp double-stranded DNA (dsDNA), with 10-bp 3′-extruding cohesive ends, and contains 48 open reading frames. The genomic organization was similar to that ofXanthomonasphage phiL7, but it lacked a group I intron in the DNA polymerase gene. Cp2 resembles morphologicallyEscherichia coliT7-like phages ofPodoviridae. The 42,963-bp linear dsDNA genome of Cp2 contained terminal repeats. The Cp2 genomic sequence has 40 open reading frames, many of which did not show detectable homologs in the current databases. By proteomic analysis, a gene cluster encoding structural proteins corresponding to the class III module of T7-like phages was identified on the Cp2 genome. Therefore, Cp1 and Cp2 were found to belong to completely different virus groups. In addition, we found that Cp1 and Cp2 use different molecules on the host cell surface as phage receptors and that host selection ofX. axonopodispv. citri strains by Cp1 and Cp2 is not determined at the initial stage by binding to receptors.

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