scholarly journals First Staphylococcal Cassette ChromosomemecContaining amecB-Carrying Gene Complex Independent of Transposon Tn6045in a Macrococcus caseolyticus Isolate from a Canine Infection

2015 ◽  
Vol 59 (8) ◽  
pp. 4577-4583 ◽  
Author(s):  
Elena Gómez-Sanz ◽  
Sybille Schwendener ◽  
Andreas Thomann ◽  
Stefanie Gobeli Brawand ◽  
Vincent Perreten

ABSTRACTA methicillin-resistantmecB-positiveMacrococcus caseolyticus(strain KM45013) was isolated from the nares of a dog with rhinitis. It contained a novel 39-kb transposon-defective completemecB-carrying staphylococcal cassette chromosomemecelement (SCCmecKM45013). SCCmecKM45013contained 49 coding sequences (CDSs), was integrated at the 3′ end of the chromosomalorfXgene, and was delimited at both ends by imperfect direct repeats functioning as integration site sequences (ISSs). SCCmecKM45013presented two discontinuous regions of homology (SCCmeccoverage of 35%) to the chromosomal and transposon Tn6045-associated SCCmec-like element ofM. caseolyticusJCSC7096: (i) themecgene complex (98.8% identity) and (ii) theccr-carrying segment (91.8% identity). Themecgene complex, located at the right junction of the cassette, also carried the β-lactamase geneblaZm(mecRm-mecIm-mecB-blaZm). SCCmecKM45013contained two cassette chromosome recombinase genes,ccrAm2andccrBm2, which shared 94.3% and 96.6% DNA identity with those of the SCCmec-like element of JCSC7096 but shared less than 52% DNA identity with the staphylococcalccrABandccrCgenes. Three distinct extrachromosomal circularized elements (the entire SCCmecKM45013, ΨSCCmecKM45013lacking theccrgenes, and SCCKM45013lackingmecB) flanked by one ISS copy, as well as the chromosomal regions remaining after excision, were detected. An unconventional circularized structure carrying themecBgene complex was associated with two extensive direct repeat regions, which enclosed two open reading frames (ORFs) (ORF46 and ORF51) flanking the chromosomalmecB-carrying gene complex. This study revealedM. caseolyticusas a potential disease-associated bacterium in dogs and also unveiled an SCCmecelement carryingmecBnot associated with Tn6045in the genusMacrococcus.

2009 ◽  
Vol 191 (19) ◽  
pp. 5964-5975 ◽  
Author(s):  
Davida S. Smyth ◽  
D. Ashley Robinson

ABSTRACT A survey of chromosomal variation in the ST239 clonal group of methicillin-resistant Staphylococcus aureus (MRSA) revealed a novel genetic element, ICE6013. The element is 13,354 bp in length, excluding a 6,551-bp Tn552 insertion. ICE6013 is flanked by 3-bp direct repeats and is demarcated by 8-bp imperfect inverted repeats. The element was present in 6 of 15 genome-sequenced S. aureus strains, and it was detected using genetic markers in 19 of 44 diverse MRSA and methicillin-susceptible strains and in all 111 ST239 strains tested. Low integration site specificity was discerned. Multiple chromosomal copies and the presence of extrachromosomal circular forms of ICE6013 were detected in various strains. The circular forms included 3-bp coupling sequences, located between the 8-bp ends of the element, that corresponded to the 3-bp direct repeats flanking the chromosomal forms. ICE6013 is predicted to encode 15 open reading frames, including an IS30-like DDE transposase in place of a Tyr/Ser recombinase and homologs of gram-positive bacterial conjugation components. Further sequence analyses indicated that ICE6013 is more closely related to ICEBs1 from Bacillus subtilis than to the only other potential integrative conjugative element known from S. aureus, Tn5801. Evidence of recombination between ICE6013 elements is also presented. In summary, ICE6013 is the first member of a new family of active, integrative genetic elements that are widely dispersed within S. aureus strains.


2013 ◽  
Vol 79 (8) ◽  
pp. 2828-2832 ◽  
Author(s):  
Lynn El Haddad ◽  
Sylvain Moineau

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.


2020 ◽  
Vol 9 (49) ◽  
Author(s):  
John C. Mullican ◽  
Kristen M. Drescher ◽  
Nora M. Chapman ◽  
Steven Tracy

ABSTRACT The circular extrachromosomal ribosomal DNA (rDNA) element of Naegleria fowleri strain LEE was molecularly cloned and fully sequenced. The element comprises 15,786 bp and contains a single copy of the organism’s rDNA cistron. The nonribosomal sequence contains five potential open reading frames, two large direct repeat sequences, and numerous smaller repeated-sequence regions.


2014 ◽  
Vol 58 (10) ◽  
pp. 6133-6138 ◽  
Author(s):  
Juliette R. K. Wipf ◽  
Sybille Schwendener ◽  
Vincent Perreten

ABSTRACTA novel erythromycin ribosome methylase gene,erm(44), that confers resistance to macrolide, lincosamide, and streptogramin B (MLSB) antibiotics was identified by whole-genome sequencing of the chromosome ofStaphylococcus xylosusisolated from bovine mastitis milk. Theerm(44) gene is preceded by a regulatory sequence that encodes two leader peptides responsible for the inducible expression of the methylase gene, as demonstrated by cloning inStaphylococcus aureus. Theerm(44) gene is located on a 53-kb putative prophage designated ΦJW4341-pro. The 56 predicted open reading frames of ΦJW4341-pro are structurally organized into the five functional modules found in members of the familySiphoviridae. ΦJW4341-pro is site-specifically integrated into theS. xylosuschromosome, where it is flanked by two perfect 19-bp direct repeats, and exhibits the ability to circularize. The presence oferm(44) in three additionalS. xylosusstrains suggests that this putative prophage has the potential to disseminate MLSBresistance.


2017 ◽  
Vol 199 (8) ◽  
Author(s):  
Emily A. Sansevere ◽  
Xiao Luo ◽  
Joo Youn Park ◽  
Sunghyun Yoon ◽  
Keun Seok Seo ◽  
...  

ABSTRACT ICE6013 represents one of two families of integrative conjugative elements (ICEs) identified in the pan-genome of the human and animal pathogen Staphylococcus aureus. Here we investigated the excision and conjugation functions of ICE6013 and further characterized the diversity of this element. ICE6013 excision was not significantly affected by growth, temperature, pH, or UV exposure and did not depend on recA. The IS30-like DDE transposase (Tpase; encoded by orf1 and orf2) of ICE6013 must be uninterrupted for excision to occur, whereas disrupting three of the other open reading frames (ORFs) on the element significantly affects the level of excision. We demonstrate that ICE6013 conjugatively transfers to different S. aureus backgrounds at frequencies approaching that of the conjugative plasmid pGO1. We found that excision is required for conjugation, that not all S. aureus backgrounds are successful recipients, and that transconjugants acquire the ability to transfer ICE6013. Sequencing of chromosomal integration sites in serially passaged transconjugants revealed a significant integration site preference for a 15-bp AT-rich palindromic consensus sequence, which surrounds the 3-bp target site that is duplicated upon integration. A sequence analysis of ICE6013 from different host strains of S. aureus and from eight other species of staphylococci identified seven divergent subfamilies of ICE6013 that include sequences previously classified as a transposon, a plasmid, and various ICEs. In summary, these results indicate that the IS30-like Tpase functions as the ICE6013 recombinase and that ICE6013 represents a diverse family of mobile genetic elements that mediate conjugation in staphylococci. IMPORTANCE Integrative conjugative elements (ICEs) encode the abilities to integrate into and excise from bacterial chromosomes and plasmids and mediate conjugation between bacteria. As agents of horizontal gene transfer, ICEs may affect bacterial evolution. ICE6013 represents one of two known families of ICEs in the pathogen Staphylococcus aureus, but its core functions of excision and conjugation are not well studied. Here, we show that ICE6013 depends on its IS30-like DDE transposase for excision, which is unique among ICEs, and we demonstrate the conjugative transfer and integration site preference of ICE6013. A sequence analysis revealed that ICE6013 has diverged into seven subfamilies that are dispersed among staphylococci.


2016 ◽  
Vol 198 (9) ◽  
pp. 1393-1400 ◽  
Author(s):  
Guangyu E. Chen ◽  
Andrew Hitchcock ◽  
Philip J. Jackson ◽  
Roy R. Chaudhuri ◽  
Mark J. Dickman ◽  
...  

ABSTRACTThe major photopigment of the cyanobacteriumAcaryochloris marinais chlorophylld, while its direct biosynthetic precursor, chlorophylla, is also present in the cell. These pigments, along with the majority of chlorophylls utilized by oxygenic phototrophs, carry an ethyl group at the C-8 position of the molecule, having undergone reduction of a vinyl group during biosynthesis. Two unrelated classes of 8-vinyl reductase involved in the biosynthesis of chlorophylls are known to exist, BciA and BciB. The genome ofAcaryochloris marinacontains open reading frames (ORFs) encoding proteins displaying high sequence similarity to BciA or BciB, although they are annotated as genes involved in transcriptional control (nmrA) and methanogenesis (frhB), respectively. These genes were introduced into an 8-vinyl chlorophylla-producing ΔbciBstrain ofSynechocystissp. strain PCC 6803, and both were shown to restore synthesis of the pigment with an ethyl group at C-8, demonstrating their activities as 8-vinyl reductases. We propose thatnmrAandfrhBbe reassigned asbciAandbciB, respectively; transcript and proteomic analysis ofAcaryochloris marinareveal that bothbciAandbciBare expressed and their encoded proteins are present in the cell, possibly in order to ensure that all synthesized chlorophyll pigment carries an ethyl group at C-8. Potential reasons for the presence of two 8-vinyl reductases in this strain, which is unique for cyanobacteria, are discussed.IMPORTANCEThe cyanobacteriumAcaryochloris marinais the best-studied phototrophic organism that uses chlorophylldfor photosynthesis. Unique among cyanobacteria sequenced to date, its genome contains ORFs encoding two unrelated enzymes that catalyze the reduction of the C-8 vinyl group of a precursor molecule to an ethyl group. Carrying a reduced C-8 group may be of particular importance to organisms containing chlorophylld. Plant genomes also contain orthologs of both of these genes; thus, the bacterial progenitor of the chloroplast may also have contained bothbciAandbciB.


2011 ◽  
Vol 77 (10) ◽  
pp. 3443-3450 ◽  
Author(s):  
Evelien M. Adriaenssens ◽  
Pieter-Jan Ceyssens ◽  
Vincent Dunon ◽  
Hans-Wolfgang Ackermann ◽  
Johan Van Vaerenbergh ◽  
...  

ABSTRACTPantoea agglomeransis a common soil bacterium used in the biocontrol of fungi and bacteria but is also an opportunistic human pathogen. It has been described extensively in this context, but knowledge of bacteriophages infecting this species is limited. Bacteriophages LIMEzero and LIMElight ofP. agglomeransare lytic phages, isolated from soil samples, belonging to thePodoviridaeand are the firstPantoeaphages of this family to be described. The double-stranded DNA (dsDNA) genomes (43,032 bp and 44,546 bp, respectively) encode 57 and 55 open reading frames (ORFs). Based on the presence of an RNA polymerase in their genomes and their overall genome architecture, these phages should be classified in the subfamily of theAutographivirinae, within the genus of the “phiKMV-like viruses.” Phylogenetic analysis of all the sequenced members of theAutographivirinaesupports the classification of phages LIMElight and LIMEzero as members of the “phiKMV-like viruses” and corroborates the subdivision into the different genera. These data expand the knowledge ofPantoeaphages and illustrate the wide host diversity of phages within the “phiKMV-like viruses.”


2012 ◽  
Vol 78 (24) ◽  
pp. 8719-8734 ◽  
Author(s):  
Mariángeles Briggiler Marcó ◽  
Josiane E. Garneau ◽  
Denise Tremblay ◽  
Andrea Quiberoni ◽  
Sylvain Moineau

ABSTRACTWe characterized twoLactobacillus plantarumvirulent siphophages, ATCC 8014-B1 (B1) and ATCC 8014-B2 (B2), previously isolated from corn silage and anaerobic sewage sludge, respectively. Phage B2 infected two of the eightL. plantarumstrains tested, while phage B1 infected three. Phage adsorption was highly variable depending on the strain used. Phage defense systems were found in at least twoL. plantarumstrains, LMG9211 and WCSF1. The linear double-stranded DNA genome of thepac-type phage B1 had 38,002 bp, a G+C content of 47.6%, and 60 open reading frames (ORFs). Surprisingly, the phage B1 genome has 97% identity with that ofPediococcus damnosusphage clP1 and 77% identity with that ofL. plantarumphage JL-1; these phages were isolated from sewage and cucumber fermentation, respectively. The double-stranded DNA (dsDNA) genome of thecos-type phage B2 had 80,618 bp, a G+C content of 36.9%, and 127 ORFs with similarities to those ofBacillusandLactobacillusstrains as well as phages. Some phage B2 genes were similar to ORFs fromL. plantarumphage LP65 of theMyoviridaefamily. Additionally, 6 tRNAs were found in the phage B2 genome. Protein analysis revealed 13 (phage B1) and 9 (phage B2) structural proteins. To our knowledge, this is the first report describing such high identity between phage genomes infecting different genera of lactic acid bacteria.


2004 ◽  
Vol 186 (10) ◽  
pp. 3202-3213 ◽  
Author(s):  
Susan M. Bueno ◽  
Carlos A. Santiviago ◽  
Alejandro A. Murillo ◽  
Juan A. Fuentes ◽  
A. Nicole Trombert ◽  
...  

ABSTRACT The large pathogenicity island (SPI7) of Salmonella enterica serovar Typhi is a 133,477-bp segment of DNA flanked by two 52-bp direct repeats overlapping the pheU (phenylalanyl-tRNA) gene, contains 151 potential open reading frames, and includes the viaB operon involved in the synthesis of Vi antigen. Some clinical isolates of S. enterica serovar Typhi are missing the entire SPI7, due to its precise excision; these strains have lost the ability to produce Vi antigen, are resistant to phage Vi-II, and invade a human epithelial cell line more rapidly. Excision of SPI7 occurs spontaneously in a clinical isolate of S. enterica serovar Typhi when it is grown in the laboratory, leaves an intact copy of the pheU gene at its novel join point, and results in the same three phenotypic consequences. SPI7 is an unstable genetic element, probably an intermediate in the pathway of lateral transfer of such pathogenicity islands among enteric gram-negative bacteria.


2020 ◽  
Vol 9 (25) ◽  
Author(s):  
Wesley D. Rhinehart ◽  
Amanda J. Laidlaw ◽  
Alexis M. O’Neal ◽  
Jessica A. Toller ◽  
Miriam Segura-Totten ◽  
...  

ABSTRACT Novel mycobacteriophage XianYue was isolated in Northeast Georgia and infects Mycobacteria smegmatis mc2155. Actinobacteriophages which share at least 50% nucleotide identity are grouped into clusters, with XianYue in cluster A2. Its genome is 52,907 bp with 91 open reading frames (ORFs) and 62.9% GC content, and it shares 86.51% nucleotide identity with mycobacteriophage Trixie.


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