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 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 A Novel Putative Enterococcal Pathogenicity Island Linked to the esp Virulence Gene of Enterococcus faecium and Associated with Epidemicity

2004 ◽  
Vol 186 (3) ◽  
pp. 672-682 ◽  
Author(s):  
Helen Leavis ◽  
Janetta Top ◽  
Nathan Shankar ◽  
Katrine Borgen ◽  
Marc Bonten ◽  
...  
Keyword(s):  
Enterococcus Faecium ◽  
Virulence Gene ◽  
Surface Protein ◽  
Pathogenicity Island ◽  
Open Reading Frames ◽  
Regulation Of Transcription ◽  
Genetic Element ◽  
Virulence Regulation ◽  
Flanking Regions ◽  
Reading Frames

ABSTRACT Enterococcus faecalis harbors a virulence-associated surface protein encoded by the esp gene. This gene has been shown to be part of a 150-kb putative pathogenicity island. A gene similar to esp has recently been found in Enterococcus faecium isolates recovered from hospitalized patients. In the present study we analyzed the polymorphism in the esp gene of E. faecium, and we investigated the association of esp with neighboring chromosomal genes. The esp gene showed considerable sequence heterogeneity in the regions encoding the nonrepeat N- and C-terminal domains of the Esp protein as well as differences in the number of repeats. DNA sequencing of chromosomal regions flanking the esp gene of E. faecium revealed seven open reading frames, representing putative genes implicated in virulence, regulation of transcription, and antibiotic resistance. These flanking regions were invariably associated with the presence or absence of the esp gene in E. faecium, indicating that esp in E. faecium is part of a distinct genetic element. Because of the presence of virulence genes in this gene cluster, the lower G+C content relative to that of the genome, and the presence of esp in E. faecium isolates associated with nosocomial outbreaks and clinically documented infections, we conclude that this genetic element constitutes a putative pathogenicity island, the first one described in E. faecium. Except for the presence of esp and araC, this pathogenicity island is completely different from the esp-containing pathogenicity island previously disclosed in E. faecalis.

scholarly journals Identification and Characterization of Conjugative Transposons CTn86 and CTn9343 in Bacteroides fragilis Strains

2006 ◽  
Vol 73 (1) ◽  
pp. 53-63 ◽  
Author(s):  
Simy L. Buckwold ◽  
Nadja B. Shoemaker ◽  
Cynthia L. Sears ◽  
Augusto A. Franco
Keyword(s):  
Dna Hybridization ◽  
Bacteroides Fragilis ◽  
Pathogenicity Island ◽  
Division I ◽  
Pcr Analysis ◽  
Genetic Element ◽  
Genetic Elements ◽  
Conjugative Transposons ◽  
Identification And Characterization

ABSTRACT The related genetic elements flanking the Bacteroides fragilis pathogenicity island (PAI) in enterotoxigenic B. fragilis (ETBF) 86-5443-2-2 and also present in pattern III nontoxigenic B. fragilis (NTBF) NCTC 9343 were defined as putative conjugative transposons (CTns), designated CTn86 and CTn9343, respectively (A. A. Franco, J. Bacteriol. 181:6623-6633, 2004). CTn86 and CTn9343 have the same basic structures except that their encoded transposases have low similarity and CTn9343 lacks the B. fragilis PAI and contains an extra 7-kb region not present in CTn86. In this study, using DNA hybridization and PCR analysis, we characterized the genetic element flanking the PAI in a collection of ETBF strains and the related genetic elements in a collection of NTBF pattern III strains. We found that in all 123 ETBF strains, the PAI is contained in a genetic element similar to CTn86. Of 73 pattern III strains, 26 (36%) present a genetic element similar to CTn9343, 38 (52%) present a genetic element similar to CTn9343 but lack the 7-kb region that is also absent in CTn86 (CTn9343-like element), and 9 (12%) present a genetic element similar to CTn86 but lacking the PAI (CTn86-like element). In addition to containing CTn86, ETBF strains can also contain CTn9343, CTn9343-like, or CTn86-like elements. CTn86, CTn9343, CTn86-like, and CTn9343-like elements were found exclusively in B. fragilis strains and predominantly in division I, cepA-positive strains.

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 Mapping the regions carrying the three contiguous antibiotic resistance genes aadE, sat4, and aphA-3 in the genomes of staphylococci.

1997 ◽  
Vol 41 (5) ◽  
pp. 1024-1032 ◽  
Author(s):  
A Derbise ◽  
S Aubert ◽  
N El Solh
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Unknown Function ◽  
Antibiotic Resistance Genes ◽  
Open Reading Frames ◽  
Restriction Fragments ◽  
Internal Part ◽  
Reading Frames ◽  
Related Element

Tn5405 (12 kb) is a staphylococcal composite transposon delimited by two inverted copies of IS1182, one of which contains IS1181. The internal part of this transposon carries three antibiotic resistance genes, aphA-3, aadE, and sat4, and three open reading frames (ORFs), orfx, orfy, and orfz, of unknown function. The dispersion of Tn5405 and the genes and ORFs included in this transposon were investigated in 50 epidemiologically unrelated staphylococci carrying aphA-3. Twenty-three maps, distinguishable by the presence or absence of the investigated genes or ORFs and/or by the sizes of the restriction fragments carrying them, were identified. Four isolates carried Tn5405, and 15 other isolates contained a Tn5405-related element. IS1182 was not detected in the aphA-3 regions mapped in 31 isolates which carried the following combinations: orfx, orfy, aadE, sat4, and aphA-3 +/- orfz; orfy, aadE, sat4, and aphA-3 +/- orfz; and aadE, sat4, aphA-3, and orfz. In all isolates, the genes and ORFs investigated were in relative positions similar to those in Tn5405. Thus, the internal part of Tn5405 appeared to be partially conserved with the maintenance, in all of the isolates, of at least the three antibiotic resistance genes.

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 Complete Genome Sequence of a Bacteroides fragilis Bacteriophage, vB_BfrS_NCTC

2021 ◽  
Vol 10 (29) ◽  
Author(s):  
Mohammad A. Tariq ◽  
Simon R. Carding
Keyword(s):  
Genome Sequence ◽  
Complete Genome Sequence ◽  
Complete Genome ◽  
Bacteroides Fragilis ◽  
Opportunistic Pathogen ◽  
Open Reading Frames ◽  
Obligate Anaerobe ◽  
Commensal Bacterium ◽  
Content Type ◽  
Reading Frames

Bacteroides fragilis is an obligate anaerobe and a common gut commensal bacterium that is also an important opportunistic pathogen. Here, we present the complete genome sequence of the circularly permuted B. fragilis bacteriophage vB_BfrS_NCTC. It comprises 47,160 bp, with 69 open reading frames.

scholarly journals A Novel Pathogenicity Island Integrated Adjacent to the thrW tRNA Gene of Avian Pathogenic Escherichia coli Encodes a Vacuolating Autotransporter Toxin

2003 ◽  
Vol 71 (9) ◽  
pp. 5087-5096 ◽  
Author(s):  
V. R. Parreira ◽  
C. L. Gyles
Keyword(s):  
Escherichia Coli ◽  
Serine Protease ◽  
Trna Gene ◽  
Signal Sequence ◽  
Sequence Similarity ◽  
Pathogenicity Island ◽  
Open Reading Frames ◽  
Integrase Gene ◽  
E Coli ◽  
Reading Frames

ABSTRACT We report the complete nucleotide sequence and genetic organization of the Vat-encoding pathogenicity island (PAI) of avian pathogenic Escherichia coli strain Ec222. The 22,139-bp PAI is situated adjacent to the 3′ terminus of the thrW tRNA gene, has a G+C content of 41.2%, and includes a bacteriophage SfII integrase gene, mobile genetic elements, two open reading frames with products exhibiting sequence similarity to known proteins, and several other open reading frames of unknown function. The PAI encodes an autotransporter protein, Vat (vacuolating autotransporter toxin), which induces the formation of intracellular vacuoles resulting in cytotoxic effects similar to those caused by the VacA toxin from Helicobacter pylori. The predicted 148.3-kDa protein product possesses the three domains that are typical of serine protease autotransporters of Enterobacteriaceae: an N-terminal signal sequence of 55 amino acids, a 111.8-kDa passenger domain containing a modified serine protease site (ATSGSG), and a C-terminal outer membrane translocator of 30.5 kDa. Vat has 75% protein homology with the hemagglutinin Tsh, an autotransporter of avian pathogenic E. coli. A vat deletion mutant of Ec222 showed no virulence in respiratory and cellulitis infection models of disease in broiler chickens. We conclude that the newly described PAI and Vat may be involved in the pathogenicity of avian septicemic E. coli strain Ec222 and other avian pathogenic E. coli strains.

Detection of potential suberinase-encoding genes in Streptomyces scabiei strains and other actinobacteria

2013 ◽  
Vol 59 (5) ◽  
pp. 294-303 ◽  
Author(s):  
Doaa Komeil ◽  
Anne-Marie Simao-Beaunoir ◽  
Carole Beaulieu
Keyword(s):  
Esterase Activity ◽  
Common Scab ◽  
Blot Hybridization ◽  
Southern Blot Hybridization ◽  
Open Reading Frames ◽  
Streptomyces Scabiei ◽  
Polymerase Chain ◽  
Encoding Genes ◽  
Reading Frames ◽  
Important Disease

Streptomyces scabiei causes common scab, an economically important disease of potato tubers. Some authors have previously suggested that S. scabiei penetration into host plant tissue is facilitated by secretion of esterase enzymes degrading suberin, a lipidic biopolymer of the potato periderm. In the present study, S. scabiei EF-35 showed high esterase activity in suberin-containing media. This strain also exhibited esterase activity in the presence of other biopolymers, such as lignin, cutin, or xylan, but at a much lower level. In an attempt to identify the esterases involved in suberin degradation, translated open reading frames of S. scabiei 87-22 were examined for the presence of protein sequences corresponding to extracellular esterases of S. scabiei FL1 and of the fungus Coprinopsis cinerea VTT D-041011, which have previously been shown to be produced in the presence of suberin. Two putative extracellular suberinase genes, estA and sub1, were identified. The presence of these genes in several actinobacteria was investigated by Southern blot hybridization, and both genes were found in most common-scab-inducing strains. Moreover, reverse transcription – polymerase chain reaction performed with S. scabiei EF-35 showed that estA was expressed in the presence of various biopolymers, including suberin, whereas the sub1 gene appeared to be specifically expressed in the presence of suberin and cutin.

scholarly journals A New Bacteroides Conjugative Transposon That Carries an ermB Gene

2003 ◽  
Vol 69 (11) ◽  
pp. 6455-6463 ◽  
Author(s):  
Anamika Gupta ◽  
Hera Vlamakis ◽  
Nadja Shoemaker ◽  
Abigail A. Salyers
Keyword(s):  
Antibiotic Resistance Genes ◽  
Open Reading Frames ◽  
Rrna Gene ◽  
Erythromycin Resistance ◽  
Gram Positive ◽  
Amino Acid Sequence Level ◽  
Conjugative Transposon ◽  
Pulsed Field ◽  
Gram Positive Bacteria ◽  
Ermb Gene

ABSTRACT The erythromycin resistance gene ermB has been found in a variety of gram-positive bacteria. This gene has also been found in Bacteroides species but only in six recently isolated strains; thus, the gene seems to have entered this genus only recently. One of the six Bacteroides ermB-containing isolates, WH207, could transfer ermB to Bacteroides thetaiotaomicron strain BT4001 by conjugation. WH207 was identified as a Bacteroides uniformis strain based on the sequence of its 16S rRNA gene. Results of pulsed-field gel electrophoresis experiments demonstrated that the transferring element was normally integrated into the Bacteroides chromosome. The element was estimated from pulsed-field gel data to be about 100 kb in size. Since the element appeared to be a conjugative transposon (CTn), it was designated CTnBST. CTnBST was able to mobilize coresident plasmids and the circular form of the mobilizable transposon NBU1 to Bacteroides and Escherichia coli recipients. A 13-kb segment that contained ermB was cloned and sequenced. Most of the open reading frames in this region had little similarity at the amino acid sequence level to any proteins in the sequence databases, but a 1,723-bp DNA segment that included a 950-bp segment downstream of ermB had a DNA sequence that was virtually identical to that of a segment of DNA found previously in a Clostridium perfringens strain. This finding, together with the finding that ermB is located on a CTn, supports the hypothesis that CTnBST could have entered Bacteroides from some other genus, possibly from gram-positive bacteria. Moreover, this finding supports the hypothesis that many transmissible antibiotic resistance genes in Bacteroides are carried on CTns.

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