Tn2009, a Tn916-Like Element Containing mef(E) in Streptococcus pneumoniae

ABSTRACT The association between the macrolide efflux gene mef(E) and the tet(M) gene was studied in two clinical strains of Streptococcus pneumoniae that belonged to serotypes 19F and 6A, respectively, and that were resistant to both tetracycline and erythromycin. The mef(E)-carrying element mega (macrolide efflux genetic assembly; 5,511 bp) was found to be inserted into a Tn916-like genetic element present in the chromosomes of the two pneumococcal strains. In both strains, mega was integrated at the same site, an open reading frame identical to orf6 of Tn916. The new composite element, Tn2009, was about 23.5 kb and, with the exception of the tet(M)-coding sequence, appeared to be identical in both strains. By sequencing of the junction fragments of Tn2009 at the site of insertion into the chromosome, it was possible to show that (i) the insertion site was identical in the two clinical strains and (ii) the integration of Tn2009 caused a 9.5 kb-deletion in the pneumococcal chromosome. It was not possible to detect the conjugal transfer of Tn2009 to a recipient pneumococcal strain; however, transfer of the whole element by transformation was shown to occur. It is possible to hypothesize that Tn2009 relies on transformation for its spread among clinical strains of S. pneumoniae.

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Organization of the Plasmid cpe Locus in Clostridium perfringens Type A Isolates

Infection and Immunity ◽

10.1128/iai.70.8.4261-4272.2002 ◽

2002 ◽

Vol 70 (8) ◽

pp. 4261-4272 ◽

Cited By ~ 51

Author(s):

Kazuaki Miyamoto ◽

Ganes Chakrabarti ◽

Yosiharu Morino ◽

Bruce A. McClane

Keyword(s):

Clostridium Perfringens ◽

Horizontal Transfer ◽

Food Poisoning ◽

Type A ◽

Gastrointestinal Diseases ◽

Open Reading Frame ◽

Enterotoxin Gene ◽

Genetic Element ◽

Reading Frame ◽

Food Borne

ABSTRACT Clostridium perfringens type A isolates causing food poisoning have a chromosomal enterotoxin gene (cpe), while C. perfringens type A isolates responsible for non-food-borne human gastrointestinal diseases carry a plasmid cpe gene. In the present study, the plasmid cpe locus of the type A non-food-borne-disease isolate F4969 was sequenced to design primers and probes for comparative PCR and Southern blot studies of the cpe locus in other type A isolates. Those analyses determined that the region upstream of the plasmid cpe gene is highly conserved among type A isolates carrying a cpe plasmid. The organization of the type A plasmid cpe locus was also found to be unique, as it contains IS1469 sequences located similarly to those in the chromosomal cpe locus but lacks the IS1470 sequences found upstream of IS1469 in the chromosomal cpe locus. Instead of those upstream IS1470 sequences, a partial open reading frame potentially encoding cytosine methylase (dcm) was identified upstream of IS1469 in the plasmid cpe locus of all type A isolates tested. Similar dcm sequences were also detected in several cpe-negative C. perfringens isolates carrying plasmids but not in type A isolates carrying a chromosomal cpe gene. Contrary to previous reports, sequences homologous to IS1470, rather than IS1151, were found downstream of the plasmid cpe gene in most type A isolates tested. Those IS1470-like sequences reside in about the same position but are oppositely oriented and defective relative to the IS1470 sequences found downstream of the chromosomal cpe gene. Collectively, these and previous results suggest that the cpe plasmid of many type A isolates originated from integration of a cpe-containing genetic element near the dcm sequences of a C. perfringens plasmid. The similarity of the plasmid cpe locus in many type A isolates is consistent with horizontal transfer of a common cpe plasmid among C. perfringens type A strains.

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Human Cytomegalovirus UL138 Open Reading Frame Is Highly Conserved in Clinical Strains

Chinese Medical Sciences Journal ◽

10.1016/s1001-9294(09)60071-7 ◽

2009 ◽

Vol 24 (2) ◽

pp. 107-111 ◽

Cited By ~ 3

Author(s):

Ying Qi ◽

Rong He ◽

Yan-ping Ma ◽

Zheng-rong Sun ◽

Yao-hua Ji ◽

...

Keyword(s):

Human Cytomegalovirus ◽

Open Reading Frame ◽

Reading Frame ◽

Clinical Strains

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Identification of the psaA Gene, Coding for Pneumococcal Surface Adhesin A, in Viridans Group Streptococci other than Streptococcus pneumoniae

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.8.5.895-898.2001 ◽

2001 ◽

Vol 8 (5) ◽

pp. 895-898 ◽

Cited By ~ 23

Author(s):

Isabel Jado ◽

Asunción Fenoll ◽

Julio Casal ◽

Amalia Pérez

Keyword(s):

Streptococcus Pneumoniae ◽

Bacterial Species ◽

Open Reading Frame ◽

Gene Encoding ◽

Reading Frame ◽

Gene Coding ◽

Pcr Products ◽

Streptococcal Species ◽

Viridans Group Streptococci ◽

High Degree

ABSTRACT The gene encoding the pneumococcal surface adhesin A (PsaA) protein has been identified in three different viridans group streptococcal species. Comparative studies of the psaA gene identified in different pneumococcal isolates by sequencing PCR products showed a high degree of conservation among these strains. PsaA is encoded by an open reading frame of 930 bp. The analysis of this fragment inStreptococcus mitis, Streptococcus oralis, andStreptococcus anginosus strains revealed a sequence identity of 95, 94, and 90%, respectively, to the corresponding open reading frame of the previously reported Streptococcus pneumoniae serotype 6B strain. Our results confirm thatpsaA is present and detectable in heterologous bacterial species. The possible implications of these results for the suitability and potential use of PsaA in the identification and diagnosis of pneumococcal diseases are discussed.

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ISCce1 and ISCce2, Two Novel Insertion Sequences in Clostridium cellulolyticum

Journal of Bacteriology ◽

10.1128/jb.185.3.714-725.2003 ◽

2003 ◽

Vol 185 (3) ◽

pp. 714-725 ◽

Cited By ~ 9

Author(s):

Hédia Maamar ◽

Pascale de Philip ◽

Jean-Pierre Bélaich ◽

Chantal Tardif

Keyword(s):

Amino Acid ◽

Insertion Site ◽

Open Reading Frame ◽

Inverted Repeats ◽

Target Sequence ◽

Insertion Sequences ◽

Reading Frame ◽

Clostridium Cellulolyticum ◽

Acid Protein ◽

Amino Acid Protein

ABSTRACT Two new insertion sequences, ISCce1 and ISCce2, were found to be inserted into the cipC gene of spontaneous mutants of Clostridium cellulolyticum. In these insertional mutants, the cipC gene was disrupted either by ISCce1 alone or by both ISCce1 and ISCce2. ISCce1 is 1,292 bp long and has one open reading frame. The open reading frame encodes a putative 348-amino-acid protein with significant levels of identity with putative proteins having unknown functions and with some transposases belonging to the IS481 and IS3 families. Imperfect 23-bp inverted repeats were found near the extremities of ISCce1. ISCce2 is 1,359 bp long, carries one open reading frame, and has imperfect 35-bp inverted repeats at its termini. The open reading frame encodes a putative 398-amino-acid protein. This protein shows significant levels of identity with transposases belonging to the IS256 family. Upon transposition, both ISCce1 and ISCce2 generate 8-bp direct repeats of the target sequence, but no consensus sequences could be identified at either insertion site. ISCce1 is copied at least 20 times in the genome, as assessed by Southern blot analysis. ISCce2 was found to be mostly inserted into ISCce1. In addition, as neither of the elements was detected in seven other Clostridium species, we concluded that they may be specific to the C. cellulolyticum strain used.

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Influenza B Virus Requires BM2 Protein for Replication

Journal of Virology ◽

10.1128/jvi.78.11.5576-5583.2004 ◽

2004 ◽

Vol 78 (11) ◽

pp. 5576-5583 ◽

Cited By ~ 25

Author(s):

Masato Hatta ◽

Hideo Goto ◽

Yoshihiro Kawaoka

Keyword(s):

Reverse Genetics ◽

Mdck Cells ◽

Open Reading Frame ◽

Initiation Codon ◽

Influenza B Virus ◽

Influenza B ◽

M Gene ◽

Reading Frame ◽

Sialidase Activity ◽

B Virus

ABSTRACT The BM2 protein of influenza B virus functions as an ion channel, which is suggested to be important for virus uncoating in endosomes of virus-infected cells. Because direct support for this function is lacking, whether BM2 plays an essential role in the viral life cycle remains unknown. We therefore attempted to generate BM2 knockout viruses by reverse genetics. Mutant viruses possessing M segments with the mutated initiation codon of BM2 protein at the stop-start pentanucleotide were viable and still expressed BM2. The introduction of multiple stop codons and a one-nucleotide deletion downstream of the stop-start pentanucleotide, in addition to disablement of the BM2 initiation codon, failed to generate viable mutant viruses, but the mutant M segments still expressed proteins that reacted with the BM2 peptide antiserum. To completely abolish BM2 expression, we generated a mutant M gene whose BM2 open reading frame was deleted. Although this mutant was not able to replicate in normal MDCK cells, it did replicate in a cell line that we established which constitutively expresses BM2. Furthermore, a virus possessing the mutant M gene lacking the BM2 open reading frame and a mutant NA gene containing the BM2 open reading frame instead of the NA open reading frame underwent multiple cycles of replication in MDCK cells, with exogenous sialidase used to supplement the deleted viral sialidase activity. These findings demonstrate that the BM2 protein is essential for influenza B virus replication.

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