# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 3008 | 0 | 0.9969 | Sequence of conjugative plasmid pIP1206 mediating resistance to aminoglycosides by 16S rRNA methylation and to hydrophilic fluoroquinolones by efflux. Self-transferable IncFI plasmid pIP1206, isolated from an Escherichia coli clinical isolate, carries two new resistance determinants: qepA, which confers resistance to hydrophylic fluoroquinolones by efflux, and rmtB, which specifies a 16S rRNA methylase conferring high-level aminoglycoside resistance. Analysis of the 168,113-bp sequence (51% G+C) revealed that pIP1206 was composed of several subregions separated by copies of insertion sequences. Of 151 open reading frames, 56 (37%) were also present in pRSB107, isolated from a bacterium in a sewage treatment plant. pIP1206 contained four replication regions (RepFIA, RepFIB, and two partial RepFII regions) and a transfer region 91% identical with that of pAPEC-O1-ColBM, a plasmid isolated from an avian pathogenic E. coli. A putative oriT region was found upstream from the transfer region. The antibiotic resistance genes tet(A), catA1, bla(TEM-1), rmtB, and qepA were clustered in a 33.5-kb fragment delineated by two IS26 elements that also carried a class 1 integron, including the sulI, qacEDelta1, aad4, and dfrA17 genes and Tn10, Tn21, and Tn3-like transposons. The plasmid also possessed a raffinose operon, an arginine deiminase pathway, a putative iron acquisition gene cluster, an S-methylmethionine metabolism operon, two virulence-associated genes, and a type I DNA restriction-modification (R-M) system. Three toxin/antitoxin systems and the R-M system ensured stabilization of the plasmid in the host bacteria. These data suggest that the mosaic structure of pIP1206 could have resulted from recombination between pRSB107 and a pAPEC-O1-ColBM-like plasmid, combined with structural rearrangements associated with acquisition of additional DNA by recombination and of mobile genetic elements by transposition. | 2008 | 18458128 |
| 820 | 1 | 0.9967 | Nucleotide sequence analysis of a transposon (Tn5393) carrying streptomycin resistance genes in Erwinia amylovora and other gram-negative bacteria. A class II Tn3-type transposable element, designated Tn5393 and located on plasmid pEa34 from streptomycin-resistant strain CA11 of Erwinia amylovora, was identified by its ability to move from pEa34 to different sites in plasmids pGEM3Zf(+) and pUCD800. Nucleotide sequence analysis reveals that Tn5393 consists of 6,705 bp with 81-bp terminal inverted repeats and generates 5-bp duplications of the target DNA following insertion. Tn5393 contains open reading frames that encode a putative transposase (tnpA) and resolvase (tnpR) of 961 and 181 amino acids, respectively. The two open reading frames are separated by a putative recombination site (res) consisting of 194 bp. Two streptomycin resistance genes, strA and strB, were identified on the basis of their DNA sequence homology to streptomycin resistance genes in plasmid RSF1010. StrA is separated from tnpR by a 1.2-kb insertion element designated IS1133. The tnpA-res-tnpR region of Tn5393 was detected in Pseudomonas syringae pv. papulans Psp36 and in many other gram-negative bacteria harboring strA and strB. Except for some strains of Erwinia herbicola, these other gram-negative bacteria lacked insertion sequence IS1133. The prevalence of strA and strB could be accounted for by transposition of Tn5393 to conjugative plasmids that are then disseminated widely among gram-negative bacteria. | 1993 | 8380801 |
| 821 | 2 | 0.9964 | DNA probes for studying streptothricin resistance evolution in enteric bacteria. Probes for the detection of streptothricin resistance genes have been derived from recombinant plasmids. These include the streptothricin resistance gene probe sat 1/2 derived from Tn 1826 and specific for both the sat-1 determinant of Tn 1825 and the sat-2 determinant of Tn 1826, and the probe sat D derived from and specific for the sat-1 determinant of transposon Tn 1825. A third streptothricin resistance gene probe, sat 3, represents the streptothricin resistance determinant sat-3 of the IncQ R plasmid pIE639. Hybridization studies did not reveal any sequence homology between sat-3 and the transposon-localized sat-1 and sat-2 determinants. Moreover, non of the different sat-determinants isolated from plasmids of gram negative bacteria hybridized with the analogous resistance determinant of Streptomyces noursei, which had been cloned and named nat by Krügel et al. (Gene, 1988, 62, 209-214). The sat 1/2 probe in combination with the sat D probe proved to be suitable for the identification and the differentiation of sat-1 and sat-2 determinants in different genetic environments. Streptothricin resistance genes related to those present on transposons Tn 1825 and Tn 1826 have been detected by hybridization with the probe sat 1/2 on plasmids isolated a long time ago before the application of streptothricins. The sat-3 determinant appears to be exclusively associated with the IncQ plasmid pIE639. | 1990 | 2166786 |
| 818 | 3 | 0.9964 | Characterization of a staphylococcal plasmid related to pUB110 and carrying two novel genes, vatC and vgbB, encoding resistance to streptogramins A and B and similar antibiotics. We isolated and sequenced a plasmid, named pIP1714 (4,978 bp), which specifies resistance to streptogramins A and B and the mixture of these compounds. pIP1714 was isolated from a Staphylococcus cohnii subsp. cohnii strain found in the environment of a hospital where pristinamycin was extensively used. Resistance to both compounds and related antibiotics is encoded by two novel, probably cotranscribed genes, (i) vatC, encoding a 212-amino-acid (aa) acetyltransferase that inactivates streptogramin A and that exhibits 58.2 to 69.8% aa identity with the Vat, VatB, and SatA proteins, and (ii) vgbB, encoding a 295-aa lactonase that inactivates streptogramin B and that shows 67% aa identity with the Vgb lactonase. pIP1714 includes a 2,985-bp fragment also found in two rolling-circle replication and mobilizable plasmids, pUB110 and pBC16, from gram-positive bacteria. In all three plasmids, the common fragment was delimited by two direct repeats of four nucleotides (GGGC) and included (i) putative genes closely related to repB, which encodes a replication protein, and to pre(mob), which encodes a protein required for conjugative mobilization and site-specific recombination, and (ii) sequences very similar to the double- and single-strand origins (dso, ssoU) and the recombination site, RSA. The antibiotic resistance genes repB and pre(mob) carried by each of these plasmids were found in the same transcriptional orientation. | 1998 | 9661023 |
| 5865 | 4 | 0.9964 | Unusual small plasmids carrying the novel resistance genes dfrK or apmA isolated from methicillin-resistant or -susceptible staphylococci. OBJECTIVES: The aims of this study were to identify small staphylococcal plasmids that carry either the trimethoprim resistance gene dfrK or the apramycin resistance gene apmA and analyse them for their structure and organization with regard to their potential role as precursors of large multiresistance plasmids that carry these genes. METHODS: Trimethoprim- or apramycin-resistant staphylococci from the strain collections of the two participating institutions were investigated for the presence of plasmid-borne dfrK or apmA genes. The dfrK- or apmA-carrying plasmids were sequenced completely and compared with sequences deposited in the databases. RESULTS: Two small plasmids, the 4957 bp dfrK-carrying plasmid pKKS966 from porcine Staphylococcus hyicus subsp. hyicus and the 4809 bp apmA-carrying plasmid pKKS49 from porcine methicillin-resistant Staphylococcus aureus were identified. Structural analysis revealed that both plasmids had a similar organization, comprising a single resistance gene (dfrK or apmA), a plasmid replication gene (rep) and three partly overlapping genes for mobilization proteins (mobA, mobB and mobC). Comparisons showed 71%-82% amino acid identity between the Rep and Mob proteins of these two plasmids; however, distinctly lesser percentages of identity to Rep and Mob proteins of staphylococci and other bacteria deposited in the databases were detected. CONCLUSIONS: Both plasmids, pKKS966 and pKKS49, appeared not to be typical staphylococcal plasmids. The homology to larger plasmids that harbour the genes apmA and/or dfrK was limited to these resistance genes and their immediate upstream and downstream regions and thus suggested that these small plasmids were not integrated into larger plasmids. | 2012 | 22718530 |
| 5184 | 5 | 0.9963 | In silico evaluation of genomic characteristics of Streptococcus infantarius subsp. infantarius for application in fermentations. This study aims to evaluate the in silico genomic characteristics of Streptococcus infantarius subsp. infantarius, isolated from Coalho cheese from Paraíba, Brazil, with a view to application in lactic fermentations. rRNA sequences from the 16S ribosomal region were used as input to GenBank, in the search for patterns that could reveal a non-pathogenic behavior of S. infantarius subsp. infantarius, comparing mobile genetic elements, antibiotic resistance genes, pan-genome analysis and multi-genome alignment among related species. S. infantarius subsp. infantarius CJ18 was the only complete genome reported by BLAST/NCBI with high similarity and after comparative genetics with complete genomes of Streptococcus agalactiae (SAG153, NJ1606) and Streptococcus thermophilus (ST106, CS18, IDCC2201, APC151) revealed that CJ18 showed a low number of transposases and integrases, infection by phage bacteria of the Streptococcus genus, absence of antibiotic resistance genes and presence of bacteriocin, folate and riboflavin producing genes. The genome alignment revealed that the collinear blocks of S. thermophilus ST106 and S. agalactiae SAG153 have inverted blocks when compared to the CJ18 genome due to gene positioning, insertions and deletions. Therefore, the strains of S. infantarius subsp. infantarius isolated from Coalho cheese from Paraíba showed genomic similarity with CJ18 and the mobility of genes analyzed in silico showed absence of pathogenicity throughout the genome of CJ18, indicating the potential of these strains for the dairy industry. | 2022 | 36417612 |
| 3000 | 6 | 0.9963 | A large conjugative Acinetobacter baumannii plasmid carrying the sul2 sulphonamide and strAB streptomycin resistance genes. Acinetobacter baumannii is an important nosocomial pathogen that often complicates treatment because of its high level of resistance to antibiotics. Though plasmids can potentially introduce various genes into bacterial strains, compared to other Gram-negative bacteria, information about the unique A. baumannii plasmid repertoire is limited. Here, whole genome sequence data was used to determine the plasmid content of strain A297 (RUH875), the reference strain for the globally disseminated multiply resistant A. baumannii clone, global clone 1(GC1). A297 contains three plasmids. Two known plasmids were present; one, pA297-1 (pRAY*), carries the aadB gentamicin, kanamycin and tobramycin resistance gene and another is an 8.7kb cryptic plasmid often found in GC1 isolates. The third plasmid, pA297-3, is 200kb and carries the sul2 sulphonamide resistance gene and strAB streptomycin resistance gene within Tn6172 and a mer mercuric ion resistance module elsewhere. pA297-3 transferred sulphonamide, streptomycin and mercuric ion resistance at high frequency to a susceptible A. baumannii recipient, and contains several genes potentially involved in conjugative transfer. However, a relaxase gene was not found. It also includes several genes encoding proteins involved in DNA metabolism such as partitioning. However, a gene encoding a replication initiation protein could not be found. pA297-3 includes two copies of a Miniature Inverted-Repeat Transposable Element (MITE), named MITE-297, bracketing a 77.5kb fragment, which contains several IS and the mer module. Several plasmids related to but smaller than pA297-3 were found in the GenBank nucleotide database. They were found in different A. baumannii clones and are wide spread. They all contain either Tn6172 or a variant in the same position in the backbone as Tn6172 in pA297-3. Some related plasmids have lost the segment between the MITE-297 copies and retain only one MITE-297. Others have segments of various lengths between two MITE-297 copies, and these can be derived from the region in pA297-3 via a deletion adjacent to IS related to IS26 such as IS1007 or IS1007-like. pA297-3 and its relatives represent a third type of conjugative Acinetobacter plasmid that contributes to the dissemination of antibiotic resistance in this species. | 2016 | 27601280 |
| 435 | 7 | 0.9963 | Molecular analysis of closely related copper- and streptomycin-resistance plasmids in Pseudomonas syringae pv. syringae. The genetic relationship of a group of copper (Cur) and streptomycin (Smr) resistance plasmids and their Pseudomonas syringae pv. syringae hosts was examined. Each of these plasmids contained sequences homologous to the oriV and par sequences from pOSU900, a cryptic P. syringae pv. syringae plasmid. Analysis of restriction digest patterns of plasmid DNA indicated that the plasmids could be clustered into four groups; two of the groups contained multiple members which differed by only a few fragments. An analysis of the host P. syringae genotypes using the arbitrarily primed PCR technique and genomic DNA indicated that the host strains could be placed in groups similar to those resulting from analysis of plasmid DNA. Southern hybridization analyses of plasmid DNA indicated that each Smr plasmid contained sequences homologous to probes specific for the strA-strB Smr genes and the transposase and resolvase genes from Tn5393. All plasmids hybridized to two additional probes derived from P. syringae plasmid DNA, but none of the plasmids contained IS51 or IS801 sequences. Furthermore, Tn5393 was mobilized, presumably by transposition, between the incompatible plasmids pPSR5 and pPSR4 in P. syringae pv. syringae FF5. The variation in molecular structure of the closely related plasmids in this study is similar to that observed with antibiotic-resistance plasmids from clinical bacteria. | 1996 | 8700971 |
| 3012 | 8 | 0.9962 | Characterization of the IncA/C plasmid pSCEC2 from Escherichia coli of swine origin that harbours the multiresistance gene cfr. OBJECTIVES: To determine the complete nucleotide sequence of the multidrug resistance plasmid pSCEC2, isolated from a porcine Escherichia coli strain, and to analyse it with particular reference to the cfr gene region. METHODS: Plasmid pSCEC2 was purified from its E. coli J53 transconjugant and then sequenced using the 454 GS-FLX System. After draft assembly, predicted gaps were closed by PCR with subsequent sequencing of the amplicons. RESULTS: Plasmid pSCEC2 is 135 615 bp in size and contains 200 open reading frames for proteins of ≥100 amino acids. Analysis of the sequence of pSCEC2 revealed two resistance gene segments. The 4.4 kb cfr-containing segment is flanked by two IS256 elements in the same orientation, which are believed to be involved in the dissemination of the rRNA methylase gene cfr. The other segment harbours the resistance genes floR, tet(A)-tetR, strA/strB and sul2, which have previously been found on other IncA/C plasmids. Except for these two resistance gene regions, the pSCEC2 backbone displayed >99% nucleotide sequence identity to that of other IncA/C family plasmids isolated in France, Chile and the USA. CONCLUSIONS: The cfr gene was identified on an IncA/C plasmid, which is well known for its broad host range and transfer and maintenance properties. The location on such a plasmid will further accelerate the dissemination of cfr and co-located resistance genes among different Gram-negative bacteria. The genetic context of cfr on plasmid pSCEC2 underlines the complexity of cfr transfer events and confirms the role that insertion sequences play in the spread of cfr. | 2014 | 24013193 |
| 434 | 9 | 0.9962 | Homologous Streptomycin Resistance Gene Present among Diverse Gram-Negative Bacteria in New York State Apple Orchards. The streptomycin resistance gene of Pseudomonas syringae pv. papulans Psp36 was cloned into Escherichia coli and used to develop a 500-bp DNA probe that is specific for streptomycin resistance in P. syringae pv. papulans. The probe is a portion of a 1-kb region shared by three different DNA clones of the resistance gene. In Southern hybridizations, the probe hybridized only with DNA isolated from streptomycin-resistant strains of P. syringae pv. papulans and not with the DNA of streptomycin-sensitive strains. Transposon insertions within the region of DNA shared by the three clones resulted in loss of resistance to streptomycin. Colony hybridization of bacteria isolated from apple leaves and orchard soil indicated that 39% of 398 streptomycin-resistant bacteria contained DNA that hybridized to the probe. These included all strains of P. syringae pv. papulans and some other fluorescent pseudomonads and nonfluorescent gram-negative bacteria, but none of the gram-positive bacteria. The same-size restriction fragments hybridized to the probe in P. syringae pv. papulans. Restriction fragment length polymorphism of this region was occasionally observed in strains of other taxonomic groups of bacteria. In bacteria other than P. syringae pv. papulans, the streptomycin resistance probe hybridized to different-sized plasmids and no relationship between plasmid size and taxonomic group or between plasmid size and orchard type, soil association, or leaf association could be detected. | 1991 | 16348415 |
| 5224 | 10 | 0.9962 | The novel macrolide resistance genes mef(F) and msr(G) are located on a plasmid in Macrococcus canis and a transposon in Macrococcus caseolyticus. OBJECTIVES: To analyse macrolide resistance in a Macrococcus canis strain isolated from a dog with an ear infection, and determine whether the resistance mechanism is also present in other bacteria, and associated with mobile genetic elements. METHODS: The whole genome of M. canis Epi0082 was sequenced using PacBio and Illumina technologies. Novel macrolide resistance determinants were identified through bioinformatic analysis, and functionality was demonstrated by expression in Staphylococcus aureus. Mobile genetic elements containing the novel genes were analysed in silico for strain Epi0082 as well as in other bacterial strains deposited in GenBank. RESULTS: M. canis Epi0082 contained a 3212 bp operon with the novel macrolide resistance genes mef(F) and msr(G) encoding a efflux protein and an ABC-F ribosomal protection protein, respectively. Cloning in S. aureus confirmed that both genes individually confer resistance to the 14- and 15-membered ring macrolides erythromycin and azithromycin, but not the 16-membered ring macrolide tylosin. A reduced susceptibility to the streptogramin B pristinamycin IA was additionally observed when msr(G) was expressed in S. aureus under erythromycin induction. Epi0082 carried the mef(F)-msr(G) operon together with the chloramphenicol resistance gene fexB in a novel 39 302 bp plasmid pMiCAN82a. The mef(F)-msr(G) operon was also found in macrolide-resistant Macrococcus caseolyticus strains in the GenBank database, but was situated in the chromosome as part of a novel 13 820 bp or 13 894 bp transposon Tn6776. CONCLUSIONS: The identification of mef(F) and msr(G) on different mobile genetic elements in Macrococcus species indicates that these genes hold potential for further dissemination of resistance to the clinically important macrolides in the bacterial population. | 2021 | 33118027 |
| 3016 | 11 | 0.9962 | Complete nucleotide sequence of the conjugative tetracycline resistance plasmid pFBAOT6, a member of a group of IncU plasmids with global ubiquity. This study presents the first complete sequence of an IncU plasmid, pFBAOT6. This plasmid was originally isolated from a strain of Aeromonas caviae from hospital effluent (Westmorland General Hospital, Kendal, United Kingdom) in September 1997 (G. Rhodes, G. Huys, J. Swings, P. McGann, M. Hiney, P. Smith, and R. W. Pickup, Appl. Environ. Microbiol. 66:3883-3890, 2000) and belongs to a group of related plasmids with global ubiquity. pFBAOT6 is 84,748 bp long and has 94 predicted coding sequences, only 12 of which do not have a possible function that has been attributed. Putative replication, maintenance, and transfer functions have been identified and are located in a region in the first 31 kb of the plasmid. The replication region is poorly understood but exhibits some identity at the protein level with replication proteins from the gram-positive bacteria Bacillus and Clostridium. The mating pair formation system is a virB homologue, type IV secretory pathway that is similar in its structural organization to the mating pair formation systems of the related broad-host-range (BHR) environmental plasmids pIPO2, pXF51, and pSB102 from plant-associated bacteria. Partitioning and maintenance genes are homologues of genes in IncP plasmids. The DNA transfer genes and the putative oriT site also exhibit high levels of similarity with those of plasmids pIPO2, pXF51, and pSB102. The genetic load region encompasses 54 kb, comprises the resistance genes, and includes a class I integron, an IS630 relative, and other transposable elements in a 43-kb region that may be a novel Tn1721-flanked composite transposon. This region also contains 24 genes that exhibit the highest levels of identity to chromosomal genes of several plant-associated bacteria. The features of the backbone of pFBAOT6 that are shared with this newly defined group of environmental BHR plasmids suggest that pFBAOT6 may be a relative of this group, but a relative that was isolated from a clinical bacterial environment rather than a plant-associated bacterial environment. | 2004 | 15574953 |
| 405 | 12 | 0.9962 | Characterization of a small plasmid (pMBCP) from bovine Pseudomonas pickettii that confers cadmium resistance. This is the first report of isolation of Pseudomonas pickettii from a normal adult bovine duodenum. This organism was one of several bacteria isolated as part of a study to examine cadmium resistance genes (cad(r)) for use in generating transgenic plants to reclaim cadmium-contaminated soils in Kansas. P. pickettii containing a plasmid of 2.2kb (designated pMBCP) grew in Luria-Bertani broth and agar containing up to 800 microM of cadmium chloride and was resistant to 16 antibiotics. Curing the organism of plasmid revealed that antibiotic resistances were not plasmid-mediated. Low-level cadmium resistance was conferred by the plasmid because uncured organism grew significantly better (P<0.05) at 55 microM compared to cured organism. Both plasmid and chromosomal DNA were probed by DNA-DNA hybridization for the presence of known cadmium resistance genes (cadA, cadC, and cadD from Gram-positive (Staphylococcus aureus), but none were detected. The plasmid had one restriction site each for BamHI, PstI, SmaI, and XhoI; two sites each for HincII, SacI, and SphI; and multiple sites for AluI and XcmI. DNA sequence analyses of the cloned and original plasmids showed a GC content of greater than 60% and no homology to any published sequences in the GenBank, European Bioinformatics Institute, or Japanese Genome Net databases. The DNA sequence is contained in GenBank accession number AF144733. Thus, pMBCP offers low-level cadmium resistance to P. picketttii. | 2003 | 12651180 |
| 448 | 13 | 0.9961 | Gene-for-gene interactions of five cloned avirulence genes from Xanthomonas campestris pv. malvacearum with specific resistance genes in cotton. A total DNA clone bank of a strain of Xanthomonas campestris pv. malvacearum (Xcm) was constructed in the cosmid vector pSa747 and transfected into Escherichia coli. The Xcm strain carries at least nine identifiable avirulence (A) genes. Clones in E. coli were mated individually into a recombination-proficient Xcm isolate carrying no known A genes. Screening was for incompatibility on congenic cotton host lines that differ by single specific resistance (R) genes. Ten different cosmid clones conferring race-specific avirulence were recovered. In most cases, the same A gene clone was recovered independently several times. Using the congenic host lines and the merodiploid transconjugant pathogen strains, five of the A genes were shown to specifically interact, gene-for-gene, with individual R genes in the congenic cotton lines. Some A/R gene interactions appeared qualitatively different from others, suggesting that the physiological mechanism(s) of gene-for-gene specified incompatibility may be unique to the interactive gene pair. All A genes appeared to be chromosomally determined, three were found linked on a single 32-kilobase clone, and the rest were spaced more than 31 kilobases apart. Colinearity of the cosmid inserts with the Xcm recipient (carrying no known A genes) chromosome was demonstrated in two of the three tested. This and other evidence suggests that at least some A genes in bacteria may have the equivalent of virulence (a) alleles. The genetics of race specificity in this phytopathogenic bacterium appeared in all respects to be identical to that found in phytopathogenic fungi. | 1986 | 16593751 |
| 3018 | 14 | 0.9961 | The large Bacillus plasmid pTB19 contains two integrated rolling-circle plasmids carrying mobilization functions. Plasmid pTB19 is a 27-kb plasmid originating from a thermophilic Bacillus species. It was shown previously that pTB19 contains an integrated copy of the rolling-circle type plasmid pTB913. Here we describe the analysis of a 4324-bp region of pTB19 conferring resistance to tetracycline. The nucleotide sequence of this region revealed all the characteristics of a second plasmid replicating via the rolling-circle mechanism. This sequence contained (i) the tetracycline resistance marker of pTB19, which is highly similar to other tetL-genes of gram-positive bacteria; (ii) a hybrid mob gene, which bears relatedness to both the mob-genes of pUB110 and pTB913; (iii) a palU type minus origin identical to those of pUB110 and pTB913; and (iv) a plus origin of replication similar to that of pTB913. A repB-type replication initiation gene sequence identical to that of pTB913 was present, which lacked the middle part (492 bp), thus preventing autonomous replication of this region. The hybrid mob gene was functional in conjugative mobilization of plasmids between strains of Bacillus subtilis. | 1991 | 1946749 |
| 5846 | 15 | 0.9961 | Distribution of tetracycline resistance genes and transposons among phylloplane bacteria in Michigan apple orchards. The extent and nature of tetracycline resistance in bacterial populations of two apple orchards with no or a limited history of oxytetracycline usage were assessed. Tetracycline-resistant (Tc(r)) bacteria were mostly gram negative and represented from 0 to 47% of the total bacterial population on blossoms and leaves (versus 26 to 84% for streptomycin-resistant bacteria). A total of 87 isolates were screened for the presence of specific Tc(r) determinants. Tc(r) was determined to be due to the presence of Tet B in Pantoea agglomerans and other members of the family Enterobacteriacae and Tet A, Tet C, or Tet G in most Pseudomonas isolates. The cause of Tc(r) was not identified in 16% of the isolates studied. The Tc(r) genes were almost always found on large plasmids which also carried the streptomycin resistance transposon Tn5393. Transposable elements with Tc(r) determinants were detected by entrapment following introduction into Escherichia coli. Tet B was found within Tn10. Two of eighteen Tet B-containing isolates had an insertion sequence within Tn10; one had IS911 located within IS10-R and one had Tn1000 located upstream of Tet B. Tet A was found within a novel variant of Tn1721, named Tn1720, which lacks the left-end orfI of Tn1721. Tet C was located within a 19-kb transposon, Tn1404, with transposition genes similar to those of Tn501, streptomycin (aadA2) and sulfonamide (sulI) resistance genes within an integron, Tet C flanked by direct repeats of IS26, and four open reading frames, one of which may encode a sulfate permease. Two variants of Tet G with 92% sequence identity were detected. | 1999 | 10543801 |
| 407 | 16 | 0.9961 | Molecular cloning and characterization of two lincomycin-resistance genes, lmrA and lmrB, from Streptomyces lincolnensis 78-11. Two different lincomycin-resistance determinants (lmrA and lmrB) from Streptomyces lincolnensis 78-11 were cloned in Streptomyces lividans 66 TK23. The gene lmrA was localized on a 2.16 kb fragment, the determined nucleotide sequence of which encoded a single open reading frame 1446 bp long. Analysis of the deduced amino acid sequence suggested the presence of 12 membrane-spanning domains and showed significant similarities to the methylenomycin-resistance protein (Mmr) from Streptomyces coelicolor, the QacA protein from Staphylococcus aureus, and several tetracycline-resistance proteins from both Gram-positive and Gram-negative bacteria, as well as to some sugar-transport proteins from Escherichia coli. The lmrB gene was actively expressed from a 2.7 kb fragment. An open reading frame of 837 bp could be localized which encoded a protein that was significantly similar to 23S rRNA adenine(2058)-N-methyltransferases conferring macrolide-lincosamide-streptogramin resistance. LmrB also had putative rRNA methyltransferase activity since lincomycin resistance of ribosomes was induced in lmrB-containing strains. Surprisingly, both enzymes, LmrA and LmrB, had a substrate specificity restricted to lincomycin and did not cause resistance to other lincosamides such as celesticetin and clindamycin, or to macrolides. | 1992 | 1328813 |
| 3046 | 17 | 0.9961 | Presence of STRA-STRB linked streptomycin-resistance genes in clinical isolate of Escherichia coil 2418. The streptomycin resistance of Escherichia coli 2418 strain has been shown to be associated with a 1.2-kb DNA fragment found in the naturally occurring plasmid R2418S. Here, nucleotide sequence analysis of the 1.2-kb DNA fragment revealed the presence of the strB gene which is located immediately downstream of the strA gene. Both sequences are identical to those of strA and strB genes in plasmid RSF1010. Thus, the observed resistance in the clinical isolate is due to the presence of strA-strB genes encoding streptomycin-modifying enzymes. The sequence downstream of strB gene showed a perfect homology with that of RSF1010. In addition, it contained the right inverted repeat of the transposon Tn5393 that has been suggested to be a relic of this transposon found in DNA plasmids isolated from human- and animal-associated bacteria. | 2010 | 21598829 |
| 3013 | 18 | 0.9961 | Nucleotide sequence and organization of the multiresistance plasmid pSCFS1 from Staphylococcus sciuri. OBJECTIVES: The multiresistance plasmid pSCFS1 from Staphylococcus sciuri was sequenced completely and analysed with regard to its gene organization and the putative role of a novel ABC transporter in antimicrobial resistance. METHODS: Plasmid pSCFS1 was transformed into Staphylococcus aureus RN4220, overlapping restriction fragments were cloned into Escherichia coli plasmid vectors and sequenced. For further analysis of the ABC transporter, a approximately 3 kb EcoRV-HpaI fragment was cloned into the staphylococcal plasmid pT181MCS and the respective S. aureus RN4220 transformants were subjected to MIC determination. RESULTS: A total of 14 ORFs coding for proteins of >100 amino acids were detected within the 17 108 bp sequence of pSCFS1. Five of them showed similarity to recombination/mobilization genes while another two were similar to plasmid replication genes. In addition to the previously described genes cfr for chloramphenicol/florfenicol resistance and erm(33) for inducible resistance to macrolide-lincosamide-streptogramin B resistance, a Tn554-like spectinomycin resistance gene and Tn554-related transposase genes were identified. Moreover, a novel ABC transporter was detected and shown to mediate low-level lincosamide resistance. CONCLUSION: Plasmid pSCFS1 is composed of various parts which show similarity to sequences known to occur on plasmids or transposons of Gram-positive, but also Gram-negative bacteria. It is likely that pSCFS1 represents the result of inter-plasmid recombination events also involving the truncation of a Tn554-like transposon. | 2004 | 15471995 |
| 3044 | 19 | 0.9961 | RSF1010 and a conjugative plasmid contain sulII, one of two known genes for plasmid-borne sulfonamide resistance dihydropteroate synthase. The nucleotide sequence of the type II sulfonamide resistance dihydropteroate synthase (sulII) gene was determined. The molecular weight determined by maxicells was 30,000, and the predicted molecular weight for the polypeptide was 28,469. Comparison with the sulI gene encoded by Tn21 showed 57% DNA similarity. The sulII-encoded polypeptide has 138 of 271 amino acids in common with the polypeptide encoded by sulI. The sulII gene is located on various IncQ (broad-host-range) plasmids and other small nonconjugative resistance plasmids. Detailed restriction maps were constructed to compare the different plasmids in which sulII is found. The large conjugative plasmid pGS05 and the IncQ plasmid RSF1010 contained identical nucleotide sequences for the sulII gene. This type of sulfonamide resistance is very frequently found among gram-negative bacteria because of its efficient spread to various plasmids. | 1988 | 3075438 |