scholarly journals Tn5406, a New Staphylococcal Transposon Conferring Resistance to Streptogramin A and Related Compounds Including Dalfopristin

2002 ◽  
Vol 46 (8) ◽  
pp. 2337-2343 ◽  
Author(s):  
Julien Haroche ◽  
Jeanine Allignet ◽  
Névine El Solh

ABSTRACT We characterized a new transposon, Tn5406 (5,467 bp), in a clinical isolate of Staphylococcus aureus (BM3327). It carries a variant of vgaA, which encodes a putative ABC protein conferring resistance to streptogramin A but not to mixtures of streptogramins A and B. It also carries three putative genes, the products of which exhibit significant similarities (61 to 73% amino acid identity) to the three transposases of the staphylococcal transposon Tn554. Like Tn554, Tn5406 failed to generate target repeats. In BM3327, the single copy of Tn5406 was inserted into the chromosomal att554 site, which is the preferential insertion site of Tn554. In three other independent S. aureus clinical isolates, Tn5406 was either present as a single plasmid copy (BM3318), as two chromosomal copies (BM3252), or both in the chromosome and on a plasmid (BM3385). The Tn5406-carrying plasmids also contain two other genes, vgaB and vatB. The insertion sites of Tn5406 in BM3252 were studied: one copy was in att554, and one copy was in the additional SCCmec element. Amplification experiments revealed circular forms of Tn5406, indicating that this transposon might be active. To our knowledge, a transposon conferring resistance to streptogramin A and related compounds has not been previously described.

2013 ◽  
Vol 79 (23) ◽  
pp. 7298-7304 ◽  
Author(s):  
Chengwei Liu ◽  
Atsushi Minami ◽  
Motoyoshi Noike ◽  
Hiroaki Toshima ◽  
Hideaki Oikawa ◽  
...  

ABSTRACTWe recently reported the function ofpaxD, which is involved in the paxilline (compound 1) biosynthetic gene cluster inPenicillium paxilli. Recombinant PaxD catalyzed a stepwise regular-type diprenylation at the 21 and 22 positions of compound 1 with dimethylallyl diphosphate (DMAPP) as the prenyl donor. In this study,atmD, which is located in the aflatrem (compound 2) biosynthetic gene cluster inAspergillus flavusand encodes an enzyme with 32% amino acid identity to PaxD, was characterized using recombinant enzyme. When compound 1 and DMAPP were used as substrates, two major products and a trace of minor product were formed. The structures of the two major products were determined to be reversely monoprenylated compound 1 at either the 20 or 21 position. Because compound 2 and β-aflatrem (compound 3), both of which are compound 1-related compounds produced byA. flavus, have the same prenyl moiety at the 20 and 21 position, respectively, AtmD should catalyze the prenylation in compound 2 and 3 biosynthesis. More importantly and surprisingly, AtmD accepted paspaline (compound 4), which is an intermediate of compound 1 biosynthesis that has a structure similar to that of compound 1, and catalyzed a regular monoprenylation of compound 4 at either the 21 or 22 position, though the reverse prenylation was observed with compound 1. This suggests that fungal indole diterpene prenyltransferases have the potential to alter their position and regular/reverse specificities for prenylation and could be applicable for the synthesis of industrially useful compounds.


1997 ◽  
Vol 41 (8) ◽  
pp. 1770-1774 ◽  
Author(s):  
T Niga ◽  
H Yoshida ◽  
H Hattori ◽  
S Nakamura ◽  
H Ito

In a study of the quinolone resistance genes in Staphylococcus aureus, a recG homolog was cloned as a gene affecting quinolone susceptibility. Sequencing analysis revealed that the gene consists of 2,061 nucleotides and encodes a 686-amino-acid polypeptide, which shows 38, 39, and 50% amino acid identity with the RecGs of Escherichia coli, Haemophilus influenzae, and Streptococcus pneumoniae, respectively. Seven helicase motifs are well conserved in the gene product. A plasmid carrying the gene complemented a recG-deficient mutant of E. coli with respect to mitomycin hypersusceptibility, demonstrating that the gene product is functionally equivalent to E. coli RecG. These results indicate that the gene is the recG gene of S. aureus. S. aureus RCM101 (recG::Tn551), designated S. aureus 3f33, is four to eight times more susceptible to quinolones than the parent strain, RCM101. The transformation of strain 3f33 with a plasmid carrying the S. aureus recG gene made it as quinolone resistant as strain RCM101. These results suggest that the recG gene is involved in the repair of DNA damage resulting from quinolone treatment in S. aureus.


1996 ◽  
Vol 42 (4) ◽  
pp. 326-334 ◽  
Author(s):  
Mark A. Farinha ◽  
Robin Mockett ◽  
Catherine J. Went ◽  
Stephanie Jardine ◽  
Lina M. Naczynski ◽  
...  

Using a series of oligonucleotides synthesized on the basis of conserved nucleotide or amino acid motifs in heat-shock genes/proteins, we have physically mapped the dnaK, lon, and hptG genes of Pseudomonas aeruginosa. Hybridization data suggest that there is a single copy of the mopBA (GroES/GroEL) operon but several additional copies of mopA. In addition, the map coordinates for the rpoD, rpoS, and rpoH genes were determined. The mopA gene from the mopBA operon was cloned and sequenced. The protein product of this gene showed 79% amino acid identity to the Escherichia coli GroEL and 98% identity to the GroEL sequence from P. aeruginosa ATCC 27853. A number of discrepancies were found with the latter sequence.Key words: Pseudomonas, heat shock, GroEL, DnaK, pulsed-field gel electrophoresis.


Development ◽  
1995 ◽  
Vol 121 (9) ◽  
pp. 2747-2754 ◽  
Author(s):  
Y. Harada ◽  
H. Yasuo ◽  
N. Satoh

Chordates are thought to have emerged from some common ancestor of deuterostomes by organizing shared anatomical and embryological features including a notochord, a dorsal nerve cord and pharyngeal gill slits. Because the notochord is the most prominent feature of chordates and because the Brachyury (T) gene is essential for notochord formation, the T gene is a key molecular probe with which to explore the origin and evolution of chordates. We investigated whether the sea urchin (echinoderm) conserves the T gene and, if so, where the sea urchin T gene is expressed. A cDNA clone for the sea urchin T (HpTa) gene contained a long open reading frame that encodes a polypeptide of 434 amino acids. Although the overall degree of amino acid identity was not very high (52%, sea urchin/mouse), in the T domain of the N terminus the amino acid identity was 73% (sea urchin/mouse). The HpTa gene is present as a single copy per haploid genome. As with the chordate T gene, the expression of HpTa is transient, being first detected in the swimming blastula, maximally transcribed in the gastrula, decreasing at the prism larval stage and barely detectable at the pluteus larval stage. HpTa transcripts were found in the secondary mesenchyme founder cells, vegetal plate of the mesenchyme blastula, extending tip of the invaginating archenteron and, finally, the secondary mesenchyme cells at the late-gastrula stage.(ABSTRACT TRUNCATED AT 250 WORDS)


2020 ◽  
Vol 70 (12) ◽  
pp. 6524-6530
Author(s):  
Craig D. Soutar ◽  
John Stavrinides

The diverse members of the Enterobacterales are agriculturally and medically relevant species that have continued to undergo taxonomic revision. To assess the current taxonomy of 64 genera of the Enterobacterales , we carried out a phylogenetic analysis using 32 single-copy core proteins. The resulting phylogeny was robust, and shows that eight genera – Biostraticola , Enterobacillus , Gibbsiella , Limnobaculum , Izhakiella , ‘Nissabacter’, Rosenbergiella and Samsonia – are currently assigned to incorrect families. Taxonomic reassignment of these genera was also supported by average amino acid identity comparisons. We propose taxonomic revision of these genera to reflect their phylogenetic position within the Enterobacterales .


2019 ◽  
Vol 5 (Supplement_1) ◽  
Author(s):  
C Torresi ◽  
F Granberg ◽  
L Bertolotti ◽  
A Oggiano ◽  
B Colitti ◽  
...  

Abstract In order to assess the molecular epidemiology of African swine fever (ASF) in Sardinia, we analyzed a wide range of isolates from wild and domestic pigs over a 31-year period (1978–2009) by genotyping sequence data from the genes encoding the p54 and the p72 proteins and the CVR. On this basis, the analysis of the B602L gene revealed a minor difference, placing the Sardinian isolates into two clusters according to their temporal distribution. As an extension of this study, in order to achieve a higher level of discrimination, three further variable genome regions, namely p30, CD2v, and I73R/I329L, of a large number of isolates collected from outbreaks in the years 2002–14 have been investigated. Sequence analysis of the CD2v region revealed a temporal subdivision of the viruses into two subgroups. These data, together with those from the B602L gene analysis, demonstrated that the viruses circulating in Sardinia belong to p72/genotype I, but since 1990 have undergone minor genetic variations in respect to its ancestor, thus making it impossible to trace isolates, enabling a more accurate assessment of the origin of outbreaks, and extending knowledge of virus evolution. To solve this problem, we have sequenced and annotated the complete genome of nine ASF isolates collected in Sardinia between 1978 and 2012. This was achieved using sequence data determined by next-generation sequencing. The results showed a very high identity with range of nucleotide similarity among isolates of 99.5 per cent to 99.9 per cent. The ASF virus (ASFV) genomes were composed of terminal inverted repeats and conserved and non-conserved ORFs. Among the conserved ORFs, B385R, H339R, and O61R-p12 showed 100 per cent amino acid identity. The same was true for the hypervariable ORFs, with regard to X69R, DP96R, DP60R, EP153R, B407L, I10L, and L60L genes. The EP402R and B602L genes showed, as expected, an amino acid identity range of 98.5 per cent to 100 per cent and 91 per cent to 100 per cent, respectively. In addition, all of the isolates displayed variable intergenic sequences. As a whole, the results from our studies confirmed a remarkable genetic stability of the ASFV/p72 genotype I viruses circulating in Sardinia.


2008 ◽  
Vol 65 (1) ◽  
pp. 21-26 ◽  
Author(s):  
Radojica Stolic ◽  
Goran Trajkovic ◽  
Vladan Peric ◽  
Aleksandar Jovanovic ◽  
Dragica Stolic ◽  
...  

Backgraund/Aim. Hemodialysis catheter, as an integral part of hemodialysis, is a catheter placed into the jugular, subclavian and femoral vein. The most common catheter-related complications are infections and thrombosis. The aim of the study was to analyze the prevalence of complications associated with differently inserted central-vein catheters for hemodialysis. Methods. The study was organized as a prospective examination during the period from December 2003 to November 2006, and included all patients who needed an active depuration by hemodialysis, hospitalized at the Clinical Center Kragujevac. The subject of the study were 464 centralvein catheters inserted during the mentioned period and there were recorded all complications related to the placement and usage of catheters. Results. The largest percent of inserted catheters was into the femoral vein ? 403 (86.8%), significantly less into the jugular vein ? 42 (9.2%), while into the subclavian vein there were placed only 19 catheters (4%). The average of femoral catheter functioning was 17 catheter days, in jugular catheters it was 17.3 days while the subclavian catheters had an average rate of functioning of 25.9 catheter days; there was found a statistically significant difference regarding the duration of functioning (p = 0.03). By microbe colonization of smear culture of the skin at the catheter insertion site, in clinically present suspicion of catheter infection, there was obtained a positive finding in 5.5% of catheters placed into the femoral vein and 7.1% of catheters instilled into the jugular vein, of which Staphylococcus aureus was the most important bacterial type, without statistically significant difference (p = 0.51). Haemoculture, done when there was a suspicion of bacteriemia, was positive in 3.7% of the patients with femoral and 4.8% with jugular catheters; Staphylococcus aureus was the most common bacteria type, but there was no statistically significant difference (p = 0.65). Colonizing the smears of the cut catheter tops, there was found a positive finding in 8.9% of femoral and 4.7% of jugular catheters in which the mentioned type of staphylococcal bacteria was prevalent, without statistically significant difference (p = 0.82). In 77% of femoral, 71.4% of jugular and 68.4% of subclavian catheters, there were no complications associated with insertion and manipulation of catheters for hemodialysis and the difference was at the limits of statistical significance (p = 0.06). Conclusion. Unconvincing rate of infections and a smaller percent of serious complications associated with the placement and use of central vein catheters instilled into the femoral vein, indicate that personal experience is sufficient recommendation to convince us that femoral vein does not represent a region with an increased risk for insertion of hemodialysis catheters.


2010 ◽  
Vol 65 (11-12) ◽  
pp. 719-725 ◽  
Author(s):  
Xiaoli Liu ◽  
Jun Chen ◽  
Zhifan Yang

Two cDNAs specific for P450 genes, CYP6AE28 and CYP6AE30, have been isolated from the rice leaf folder Cnaphalocrocis medinalis Guenée (Lepidoptera: Pyralidae). Both cDNApredicted proteins have 504 amino acid residues in length, but with molecular masses of 60177 Dalton for CYP6AE28 and 60020 Dalton for CYP6AE30, and theoretical pI values of 8.49 for CYP6AE28 and 8.56 for CYP6AE30, respectively. Both putative proteins contain the conserved structural and functional domains characteristic of all CYP6 members. CYP6AE28 and CYP6AE30 show 52% amino acid identity to each other; both of them have 49 - 56% identities with CYP6AE1, Cyp6ae12, and CYP6AE14. Phylogenetic analysis showed that the two P450s are grouped in the lineage containing some of the CYP6AE members, CYP6B P450s and CYP321A1. The transcripts of CYP6AE28 and CYP6AE30 were found to be induced in response to TKM-6, a rice variety with high resistance to C. medinalis. The results suggest that the two P450s may play important roles in adaptation to the host plant rice. This is the first report of P450 genes cloned in C. medinalis


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