scholarly journals Integrative and Sequence Characteristics of a Novel Genetic Element, ICE6013, in Staphylococcus aureus

2009 ◽  
Vol 191 (19) ◽  
pp. 5964-5975 ◽  
Author(s):  
Davida S. Smyth ◽  
D. Ashley Robinson
Keyword(s):  
Staphylococcus Aureus ◽  
Integration Site ◽  
Open Reading Frames ◽  
Bacterial Conjugation ◽  
Genetic Element ◽  
Direct Repeats ◽  
New Family ◽  
Integrative Conjugative Element ◽  
Sequence Characteristics ◽  
Reading Frames

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.

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
Keyword(s):  
Integration Site ◽  
Direct Repeat ◽  
Open Reading Frames ◽  
Gene Complex ◽  
Direct Repeats ◽  
Content Type ◽  
Canine Infection ◽  
The Right ◽  
Lactamase Gene ◽  
Reading Frames

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.

scholarly journals A New Class of Genetic Element, Staphylococcus Cassette Chromosome mec, Encodes Methicillin Resistance in Staphylococcus aureus

2000 ◽  
Vol 44 (6) ◽  
pp. 1549-1555 ◽  
Author(s):  
Y. Katayama ◽  
T. Ito ◽  
K. Hiramatsu
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistance ◽  
Open Reading Frames ◽  
Multicopy Plasmid ◽  
Sequence Determination ◽  
New Class ◽  
New Family ◽  
Partial Homology ◽  
Reading Frames

ABSTRACT We have previously shown that the methicillin-resistance genemecA of Staphylococcus aureus strain N315 is localized within a large (52-kb) DNA cassette (designated the staphylococcal cassette chromosome mec[SCCmec]) inserted in the chromosome. By sequence determination of the entire DNA, we identified two novel genes (designated cassette chromosome recombinase genes [ccrAand ccrB]) encoding polypeptides having a partial homology to recombinases of the invertase/resolvase family. The open reading frames were found to catalyze precise excision of the SCCmec from the methicillin-resistant S. aureuschromosome and site-specific as well as orientation-specific integration of the SCCmec into the S. aureuschromosome when introduced into the cells as a recombinant multicopy plasmid. We propose that SCCmec driven by a novel set of recombinases represents a new family of staphylococcal genomic elements.

scholarly journals The Bacteroides fragilis Pathogenicity Island Is Contained in a Putative Novel Conjugative Transposon

2004 ◽  
Vol 186 (18) ◽  
pp. 6077-6092 ◽  
Author(s):  
Augusto A. Franco
Keyword(s):  
Blot Hybridization ◽  
Bacteroides Fragilis ◽  
Antibiotic Resistance Genes ◽  
Pathogenicity Island ◽  
Open Reading Frames ◽  
Genetic Element ◽  
Conjugative Transposon ◽  
Conjugative Transposons ◽  
New Family ◽  
Reading Frames

ABSTRACT The genetic element flanking the Bacteroides fragilis pathogenicity island (BfPAI) in enterotoxigenic B. fragilis (ETBF) strain 86-5443-2-2 and a related genetic element in NCTC 9343 were characterized. The results suggested that these genetic elements are members of a new family of conjugative transposons (CTns) not described previously. These putative CTns, designated CTn86 and CTn9343 for ETBF 86-5443-2-2 and NCTC 9343, respectively, differ from previously described Bacteroides species CTns in a number of ways. These new transposons do not carry tetQ, and the excision from the chromosome to form a circular intermediate is not regulated by tetracycline; they are predicted to differ in their mechanism of transposition; and their sequences have very limited similarity with CTnDOT or other described CTns. CTn9343 is 64,229 bp in length, contains 61 potential open reading frames, and both ends contain IS21 transposases. Colony blot hybridization, PCR, and sequence analysis indicated that CTn86 has the same structure as CTn9343 except that CTn86 lacks a ∼7-kb region containing truncated integrase (int2) and rteA genes and it contains the BfPAI integrated between the mob region and the bfmC gene. If these putative CTns were to be demonstrated to be transmissible, this would suggest that the bft gene can be transferred from ETBF to nontoxigenic B. fragilis strains by a mechanism similar to that for the spread of antibiotic resistance genes.

scholarly journals Characterization and Genome Analysis of Staphylococcus aureus Podovirus CSA13 and Its Anti-Biofilm Capacity

Viruses ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 54 ◽  
Author(s):  
Yoyeon Cha ◽  
Jihwan Chun ◽  
Bokyung Son ◽  
Sangryeol Ryu
Keyword(s):  
Staphylococcus Aureus ◽  
Biocontrol Agent ◽  
Genomic Analysis ◽  
Open Reading Frames ◽  
Experimental Setting ◽  
Human Pathogens ◽  
Bacteriophage Therapy ◽  
Chromosomal Structure ◽  
Inhibition Effect ◽  
Reading Frames

Staphylococcus aureus is one of the notable human pathogens that can be easily encountered in both dietary and clinical surroundings. Among various countermeasures, bacteriophage therapy is recognized as an alternative method for resolving the issue of antibiotic resistance. In the current study, bacteriophage CSA13 was isolated from a chicken, and subsequently, its morphology, physiology, and genomics were characterized. This Podoviridae phage displayed an extended host inhibition effect of up to 23 hours of persistence. Its broad host spectrum included methicillin susceptible S. aureus (MSSA), methicillin resistant S. aureus (MRSA), local S. aureus isolates, as well as non-aureus staphylococci strains. Moreover, phage CSA13 could successfully remove over 78% and 93% of MSSA and MRSA biofilms in an experimental setting, respectively. Genomic analysis revealed a 17,034 bp chromosome containing 18 predicted open reading frames (ORFs) without tRNAs, representing a typical chromosomal structure of the staphylococcal Podoviridae family. The results presented here suggest that phage CSA13 can be applicable as an effective biocontrol agent against S. aureus.

scholarly journals Transposase-Mediated Excision, Conjugative Transfer, and Diversity of ICE6013 Elements in Staphylococcus aureus

2017 ◽  
Vol 199 (8) ◽  
Author(s):  
Emily A. Sansevere ◽  
Xiao Luo ◽  
Joo Youn Park ◽  
Sunghyun Yoon ◽  
Keun Seok Seo ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Sequence Analysis ◽  
Integration Site ◽  
Consensus Sequence ◽  
Open Reading Frames ◽  
Conjugative Plasmid ◽  
Site Preference ◽  
Conjugative Transfer ◽  
Content Type ◽  
Integrative Conjugative Elements

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.

scholarly journals Precise Excision of the Large Pathogenicity Island, SPI7, in Salmonella enterica Serovar Typhi

2004 ◽  
Vol 186 (10) ◽  
pp. 3202-3213 ◽  
Author(s):  
Susan M. Bueno ◽  
Carlos A. Santiviago ◽  
Alejandro A. Murillo ◽  
Juan A. Fuentes ◽  
A. Nicole Trombert ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Pathogenicity Island ◽  
Open Reading Frames ◽  
Epithelial Cell Line ◽  
Direct Repeats ◽  
Salmonella Enterica Serovar Typhi ◽  
Precise Excision ◽  
Join Point ◽  
Reading Frames ◽  
Vi Antigen

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.

scholarly journals Characterization of a Genetic Element Carrying the Macrolide Efflux Gene mef(A) in Streptococcus pneumoniae

2000 ◽  
Vol 44 (9) ◽  
pp. 2585-2587 ◽  
Author(s):  
Maria Santagati ◽  
Francesco Iannelli ◽  
Marco R. Oggioni ◽  
Stefania Stefani ◽  
Gianni Pozzi
Keyword(s):  
Streptococcus Pneumoniae ◽  
Resistance Gene ◽  
Clinical Isolate ◽  
Open Reading Frames ◽  
Genetic Element ◽  
Reading Frames

ABSTRACT The mef(A) gene from a clinical isolate ofStreptococcus pneumoniae exhibiting the M-type resistance to macrolides was found to be part of the 7,244-bp chromosomal element Tn1207.1, which contained 8 open reading frames.orf2 encodes a resolvase/invertase, and orf5 is a homolog of the macrolide-streptogramin B resistance genemsr(SA).

scholarly journals The Insertion Sequences of Anabaena sp. Strain PCC 7120 and Their Effects on Its Open Reading Frames

2010 ◽  
Vol 192 (20) ◽  
pp. 5289-5303 ◽  
Author(s):  
C. Peter Wolk ◽  
Sigal Lechno-Yossef ◽  
Karin M. Jäger
Keyword(s):  
Transposable Elements ◽  
Open Reading Frames ◽  
Insertion Sequences ◽  
Direct Repeats ◽  
Homologous Sequences ◽  
Anabaena Sp ◽  
Pcc 7120 ◽  
Flanking Regions ◽  
Adaptive Role ◽  
Reading Frames

ABSTRACT Anabaena sp. strain PCC 7120, widely studied, has 145 annotated transposase genes that are part of transposable elements called insertion sequences (ISs). To determine the entirety of the ISs, we aligned transposase genes and their flanking regions; identified the ISs' possible terminal inverted repeats, usually flanked by direct repeats; and compared IS-interrupted sequences with homologous sequences. We thereby determined both ends of 87 ISs bearing 110 transposase genes in eight IS families (http://www-is.biotoul.fr/ ) and in a cluster of unclassified ISs, and of hitherto unknown miniature inverted-repeat transposable elements. Open reading frames were then identified to which ISs contributed and others—some encoding proteins of predictable function, including protein kinases, and restriction endonucleases—that were interrupted by ISs. Anabaena sp. ISs were often more closely related to exogenous than to other endogenous ISs, suggesting that numerous variant ISs were not degraded within PCC 7120 but transferred from without. This observation leads to the expectation that further sequencing projects will extend this and similar analyses. We also propose an adaptive role for poly(A) sequences in ISs.

scholarly journals Structural Comparison of Three Types of Staphylococcal Cassette Chromosome mec Integrated in the Chromosome in Methicillin-Resistant Staphylococcus aureus

2001 ◽  
Vol 45 (5) ◽  
pp. 1323-1336 ◽  
Author(s):  
Teruyo Ito ◽  
Yuki Katayama ◽  
Kazumi Asada ◽  
Namiko Mori ◽  
Kanae Tsutsumimoto ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Integration Site ◽  
Direct Repeats ◽  
Methicillin Resistant ◽  
Genetic Elements ◽  
The World ◽  
Different Types ◽  
Junction Points ◽  
Mrsa Strains ◽  
Staphylococcal Cassette Chromosome

ABSTRACT The β-lactam resistance gene mecA ofStaphylococcus aureus is carried by a novel mobile genetic element, designated staphylococcal cassette chromosome mec(SCCmec), identified in the chromosome of a Japanese methicillin-resistant S. aureus (MRSA) strain. We now report identification of two additional types ofmecA-carrying genetic elements found in the MRSA strains isolated in other countries of the world. There were substantial differences in the size and nucleotide sequences between the elements and the SCCmec. However, new elements shared the chromosomal integration site with the SCCmec. Structural analysis of the new elements revealed that they possessed all of the salient features of the SCCmec: conserved terminal inverted repeats and direct repeats at the integration junction points, conserved genetic organization around the mecA gene, and the presence of cassette chromosome recombinase (ccr) genes responsible for the movements of SCCmec. The elements, therefore, were considered to comprise the SCCmec family of staphylococcal mobile genetic elements together with the previously identified SCCmec. Among 38 epidemic MRSA strains isolated in 20 countries, 34 were shown to possess one of the three typical SCCmec elements on the chromosome. Our findings indicated that there are at least three distinct MRSA clones in the world with different types of SCCmec in their chromosome.

scholarly journals Evolution of the Major Pilus Gene Cluster ofHaemophilus influenzae

1998 ◽  
Vol 180 (17) ◽  
pp. 4693-4703 ◽  
Author(s):  
Tendai Mhlanga-Mutangadura ◽  
Gregory Morlin ◽  
Arnold L. Smith ◽  
Abraham Eisenstark ◽  
Miriam Golomb
Keyword(s):  
Insertion Site ◽  
Data Bank ◽  
Open Reading Frames ◽  
Direct Repeats ◽  
Chromosomal Locus ◽  
Human Respiratory Tract ◽  
Small Proteins ◽  
Ofhaemophilus Influenzae ◽  
Hypothetical Ancestor ◽  
Reading Frames

ABSTRACT Haemophilus influenzae is a ubiquitous colonizer of the human respiratory tract and causes diseases ranging from otitis media to meningitis. Many H. influenzae isolates express pili (fimbriae), which mediate adherence to epithelial cells and facilitate colonization. The pilus gene (hif) cluster of H. influenzae type b maps between purE andpepN and resembles a pathogenicity island: it is present in invasive strains, absent from the nonpathogenic Rd strain, and flanked by direct repeats of sequence at the insertion site. To investigate the evolution and role in pathogenesis of the hif cluster, we compared the purE-pepN regions of various H. influenzae laboratory strains and clinical isolates. Unlike Rd, most strains had an insert at this site, which usually was the only chromosomal locus of hif DNA. The inserts are diverse in length and organization: among 20 strains, nine different arrangements were found. Several nontypeable isolates lack hif genes but have two conserved open reading frames (hicA andhicB) upstream of purE; their inferred products are small proteins with no data bank homologs. Other isolates havehif genes but lack hic DNA or have combinations of hif and hic genes. By comparing these arrangements, we have reconstructed a hypothetical ancestral genotype, the extended hif cluster. The hif region of INT1, an invasive nontypeable isolate, resembles the hypothetical ancestor. We propose that a progenitor strain acquired the extended cluster by horizontal transfer and that other variants arose as deletions. The structure of the hif cluster may correlate with colonization site or pathogenicity.

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