# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 812 | 0 | 0.9708 | Characterization of plQ5 plasmid originating fromKlebsiella pneumoniae. plQ5 plasmid consists of a group of genes specifying resistance to ampicillin, chloramphenicol, carbencillin, kanamycin and trimethoprim-sulphamethoxazole. It is isolated inKlebslella pneumoniae ZD532, is about 26.8 Kb and is freely transmissible to various bacterial species of Gram-negative bacteria. Physical characterization revealed that plQ5 plasmid has a single site forHindill,BamHI,EcoRI and two sites forBglII restriction enzyme. | 1990 | 24429982 |
| 826 | 1 | 0.9661 | Sequence identity with type VIII and association with IS176 of type IIIc dihydrofolate reductase from Shigella sonnei. An uncommon dihydrofolate reductase (DHFR), type IIIc, was coded for by Shigella sonnei that harbors plasmid pBH700 and that was isolated in North Carolina. The trimethoprim resistance gene carried on pBH700 was subcloned and sequenced. The nucleotide sequence of the gene encoding type IIIc DHFR was identical to the gene encoding type VIII DHFR. The type IIIc amino acid sequence was approximately 50% similar to those of DHFRs commonly found in enteric bacteria. Furthermore, this gene was flanked by IS176 (IS26), an insertion sequence usually associated with those of aminoglycoside resistance genes. The gene for type IIIc DHFR was located by hybridization within a 1,993-bp PstI fragment in each of eight conjugative plasmids from geographically diverse strains of S. sonnei. Each plasmid also conferred resistance to ampicillin, streptomycin, and sulfamethoxazole and belonged to incompatibility group M. Plasmids carrying this new trimethoprim resistance gene, which is uniquely associated with IS176, have disseminated throughout the United States. | 1995 | 7695291 |
| 534 | 2 | 0.9657 | Plasmid shuttle vector with two insertionally inactivable markers for coryneform bacteria. A new shuttle vector pCEM500 replicating in Escherichia coli and in Brevibacterium flavum was constructed. It carries two antibiotic resistance determinants (Kmr/Gmr from plasmid pSa of Gram-negative bacteria and Smr/Spr from plasmid pCG4 of Corynebacterium glutamicum) which are efficiently expressed in both hosts and can be inactivated by insertion of DNA fragments into the unique restriction endonuclease sites located within them. This vector was found to be stably maintained in B. flavum and can be used for transfer of the cloned genes into this amino-acid-producing coryneform bacterium. | 1990 | 2148164 |
| 819 | 3 | 0.9657 | Trimethoprim resistance transposon Tn4003 from Staphylococcus aureus encodes genes for a dihydrofolate reductase and thymidylate synthetase flanked by three copies of IS257. Trimethoprim resistance mediated by the Staphylococcus aureus multi-resistance plasmid pSK1 is encoded by a structure with characteristics of a composite transposon which we have designated Tn4003. Nucleotide sequence analysis of Tn4003 revealed it to be 4717 bp in length and to contain three copies of the insertion element IS257 (789-790 bp), the outside two of which are flanked by directly repeated 8-bp target sequences. IS257 has imperfect terminal inverted repeats of 27-28 bp and encodes for a putative transposase with two potential alpha-helix-turn-alpha-helix DNA recognition motifs. IS257 shares sequence similarities with members of the IS15 family of insertion sequences from Gram-negative bacteria and with ISS1 from Streptococcus lactis. The central region of the transposon contains the dfrA gene that specifies the S1 dihydrofolate reductase (DHFR) responsible for trimethoprim resistance. The S1 enzyme shows sequence homology with type I and V trimethoprim-resistant DHFRs from Gram-negative bacteria and with chromosomally encoded DHFRs from Gram-positive and Gram-negative bacteria. 5' to dfrA is a thymidylate synthetase gene, designated thyE. | 1989 | 2548057 |
| 530 | 4 | 0.9646 | Location of the genes for anthranilate synthase in Streptomyces venezuelae ISP5230: genetic mapping after integration of the cloned genes. The anthranilate synthase (trpEG) genes in Streptomyces venezuelae ISP5230 were located by allowing a segregationally unstable plasmid carrying cloned S. venezuelae trpEG DNA and a thiostrepton resistance (tsr) marker to integrate into the chromosome. The integrated tsr was mapped by conjugation and transduction to a location close to tyr-2, between arg-6 and trpA13. A genomic DNA fragment containing trpC from S. venezuelae ISP5230 was cloned by complementation of a trpC mutation in Streptomyces lividans. Evidence from restriction enzyme analysis of the cloned DNA fragments, from Southern hybridization using the cloned trp DNA as probes, and from cotransduction frequencies, placed trpEG at a distance of 12-45 kb from the trpCBA cluster. The overall arrangement of tryptophan biosynthesis genes in the S. venezuelae chromosome differs from that in other bacteria examined so far. | 1993 | 8515229 |
| 3053 | 5 | 0.9641 | Expression in Escherichia coli of cryptic tetracycline resistance genes from bacteroides R plasmids. The putative clindamycin resistance region of the Bacteroides fragilis R plasmid pBF4 was cloned in the vector R300B in Escherichia coli. This 3.8-kb EcoRI D fragment from pBF4 expressed noninducible tetracycline resistance in E. coli under aerobic but not anaerobic growth conditions. The fragment does not express tetracycline resistance in Bacteroides, a strict anaerobe. The separate tetracycline resistance transfer system in the Bacteroides host strain V479-1 has no homology to the cryptic determinant on pBF4. In addition, this aerobic tetracycline resistance determinant is not homologous to the three major plasmid mediated tetracycline resistance regions found in facultative gram-negative bacteria, represented by R100, RK2, and pBR322. A similar cryptic tetracycline resistance fragment was cloned from pCP1, a separate clindamycin resistance plasmid from Bacteroides that shares homology with the EcoRI D fragment of pBF4. This study identifies cryptic drug resistance determinants in Bacteroides that are expressed when inserted into an aerobically growing organism. | 1984 | 6379711 |
| 3054 | 6 | 0.9636 | Acquisition by a Campylobacter-like strain of aphA-1, a kanamycin resistance determinant from members of the family Enterobacteriaceae. A Campylobacter-like organism, BM2196, resistant to kanamycin and streptomycin-spectinomycin was isolated from the feces of a patient with acute enteritis. The kanamycin and streptomycin-spectinomycin resistances were not transferable to Camplylobacter sp. or to Escherichia coli, and no plasmid DNA was detected in this strain. The resistance genes were therefore tentatively assigned to a chromosomal locality. Analysis by the phosphocellulose paper-binding assay of extracts from BM2196 indicated that resistance to kanamycin and structurally related antibiotics was due to the synthesis of 3'-aminoglycoside phosphotransferase type I [APH(3')-I], an enzyme specific for gram-negative bacteria, and that resistance to streptomycin-spectinomycin was secondary to the presence of a 3",9-aminoglycoside adenylyltransferase. Homology between BM2196 and an APH(3')-I probe was detected by DNA-DNA hybridization. A 2.2-kilobase BM2196 DNA fragment conferring resistance to kanamycin was cloned in E. coli and was sequenced partially. The resistance gene appeared nearly identical to that of Tn903 from E. coli and was adjacent to IS15-delta, an insertion sequence widespread in gram-negative bacteria, thus indicating that Campylobacter species can act as a recipient for genes originating in members of the family Enterobacteriaceae. | 1987 | 2821885 |
| 3049 | 7 | 0.9633 | Characterisation of plasmids purified from Acetobacter pasteurianus 2374. Four cryptic plasmids pAP1, pAP2, pAP3, and pAP4 with their replication regions AP were isolated from Gram-negative bacteria Acetobacter pasteurianus 2374 and characterised by sequence analyses. All plasmids were carrying the kanamycin resistance gene. Three of four plasmids pAP2, pAP3, and pAP4 encode an enzyme that confers ampicillin resistance to host cells. Moreover, the tetracycline resistance gene was identified only in pAP2 plasmid. All plasmids are capable to coexist with each other in Acetobacter cells. On the other hand, the coexistence of more than one plasmid is excluded in Escherichia coli. The nucleotide sequence of replication regions showed significant homology. The nucleotide and protein sequence analyses of resistance genes of all plasmids were compared with transposons Tn3, Tn10, and Tn903 which revealed significant differences in the primary structure, however no functional changes of gene were obtained. | 2003 | 14511653 |
| 820 | 8 | 0.9632 | 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 |
| 3038 | 9 | 0.9631 | Biotinylated probes for epidemiological studies of drug resistance in Salmonella krefeld. A gene probe for ampicillin resistance and one for sulphonamide resistance were prepared to study the origin and the relation of multiple drug resistances in Salmonella krefeld. The resistance genes were cloned into the pACYC184 vector of Escherichia coli from a common plasmid of S. krefeld that encoded for resistance to ampicillin, chloramphenicol, kanamycin, streptomycin, sulphonamide and tetracycline resistance. Restriction map analysis and deletion analysis of a recombinant plasmid (pACSS1) showed that the gene determining ampicillin resistance was located on a 1.34 and 1.12 kb PstI fragment, and that the gene for sulphonamide resistance was located on a 0.85 kb PstI fragment. These fragments were used as probes. Their specificity was tested by colony hybridization with various bacterial species, including sensitive and resistance S. krefeld isolates. Further study indicated that the ampicillin resistance gene probe reacted with the gene for TEM-1 beta-lactamase and that the gene probe for sulphonamide resistance reacted with the gene for type II dihydropteroate synthase. The two probes were sufficiently specific to allow study of the epidemiology of resistance in S. krefeld and other enteric bacteria. | 1990 | 2190970 |
| 3050 | 10 | 0.9629 | The type VII dihydrofolate reductase: a novel plasmid-encoded trimethoprim-resistant enzyme from gram-negative bacteria isolated in Britain. Plasmid pUN835 was identified in an Escherichia coli strain isolated from an outbreak of porcine diarrhoea on a farm near Nottingham, UK. The trimethoprim resistance gene did not hybridize with any of the gene probes derived from known plasmid-encoded trimethoprim resistance genes. The trimethoprim resistance gene of pUN835 was shown to encode the production of a dihydrofolate reductase which confers high-level resistance on its host. This enzyme was smaller than most plasmid-encoded dihydrofolate reductases (molecular mass = 11,500) and was labile to heat. It had relatively low affinity for the substrate dihydrofolate (Km = 20 microM) and it was resistant to competitive inhibition by trimethoprim (Ki = 7.0 microM). We classify this novel enzyme as type VII. | 1989 | 2676936 |
| 407 | 11 | 0.9629 | 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 |
| 431 | 12 | 0.9628 | Nucleotide sequence analysis of the complement resistance gene from plasmid R100. The multiple antibiotic resistance plasmid R100 renders Escherichia coli resistant to the bactericidal action of serum complement. We constructed a plasmid (pOW3) consisting of a 1,900-base-pair-long restriction fragment from R100 joined to a 2,900-base-pair-long fragment of pBR322 carrying ampicillin resistance. E. coli strains carrying pOW3 or R100 were up to 10,000-fold less sensitive to killing by serum complement than were plasmid-free bacteria or bacteria carrying pBR322. Nucleotide sequencing revealed that 875 of the 1,900 bases from R100 correspond exactly to part of the bacterial insertion sequence IS2. The remaining 1,075 bases contained only one sizeable open reading frame; it covered 729 base pairs (243 amino acids) and was preceded by nucleotide sequences characteristic of bacterial promoters and ribosome binding sites. The first 20 amino acids of the predicted protein showed features characteristic of a signal sequence. The remainder of the predicted protein showed an amino acid composition almost identical with that determined for the traT protein from the E. coli F factor. Southern blot analysis showed that the resistance gene from R100 does not hybridize to the serum resistance gene from ColV,I-K94 isolated by Binns et al.; we concluded that these genes are distinct. | 1982 | 6284713 |
| 533 | 13 | 0.9627 | Construction of broad-host-range cosmid cloning vectors: identification of genes necessary for growth of Methylobacterium organophilum on methanol. Four new cloning vectors have been constructed from the broad-host-range cloning vector pRK290. These vectors, pLA2901, pLA2905, pLA2910, and pLA2917, confer resistance to kanamycin and tetracycline. The latter two are cosmid derivatives of pLA2901. The new vectors can be mobilized into, and are stably maintained in, a variety of gram-negative bacteria. A Sau3A genomic bank of Methylobacterium organophilum strain xx DNA has been constructed in pLA2917, and complementation analysis, with a variety of mutants unable to grow on methanol, revealed at least five separate regions necessary for growth on methanol. Complementation analysis and Tn5 mutagenesis data suggest that at least three genes are responsible for expression of active methanol dehydrogenase. | 1985 | 2982796 |
| 3051 | 14 | 0.9625 | Nucleotide sequence of the bacterial streptothricin resistance gene sat3. The nucleotide sequence of the sat3 gene which encodes resistance of enteric bacteria to the antibiotic streptothricin is reported. A protein with a molecular mass of about 23 kDa is expressed from this gene. The sat3 gene is not obviously related to any one of the streptothricin resistance determinants identified so far among Gram-negative or Gram-positive bacteria. | 1995 | 7640311 |
| 359 | 15 | 0.9625 | Construction of shuttle cloning vectors for Bacteroides fragilis and use in assaying foreign tetracycline resistance gene expression. Shuttle vectors capable of replication in both Escherichia coli and Bacteroides fragilis have been developed. Conjugal transfer of these plasmids from E. coli to B. fragilis is facilitated by inclusion of the origin of transfer of the IncP plasmid RK2. The vectors pDK1 and pDK2 provide unique sites for cloning selectable markers in Bacteroides. pOA10 is a cosmid vector containing the replication region of pCP1 necessary for maintenance in Bacteroides. pDK3, pDK4.1, and pDK4.2 contain the Bacteroides clindamycin resistance gene allowing selection and maintenance in B. fragilis of plasmids containing inserted DNA fragments. pDK3 was used to test the expression in B. fragilis of five foreign tetracycline resistance (TcR) genes. The tetA, -B, and -C markers from facultative gram-negative bacteria, as well as a TcR determinant from Clostridium perfringens, did not express TcR in B. fragilis. The tetM gene, originally described in streptococci, encoded a small but reproducible increase of TcR in Bacteroides. These studies demonstrate the utility of shuttle vectors for introducing cloned genes into Bacteroides and underscore the differences in gene expression in these anaerobes. | 1988 | 3071818 |
| 360 | 16 | 0.9624 | Broad host range cloning vectors for gram-negative bacteria. A series of cloning vectors has been constructed based on the broad-host-range plasmid R300B. One of these vectors, pGSS33, has a size of 13.4 kb and carries four antibiotic resistance genes [ampicillin (Apr), chloramphenicol (Cmr), streptomycin (Smr) and tetracycline (Tcr)], all of which have restriction sites for insertional inactivation. The derivation, structure and uses of the plasmids are described. | 1984 | 6092235 |
| 503 | 17 | 0.9624 | Interaction of the chromosomal Tn 551 with two thermosensitive derivatives, pS1 and p delta D, of the plasmid pI9789 in Staphylococcus aureus. The plasmid pI9789::Tn552 carries genes conferring resistance to penicillins and to cadmium, mercury and arsenate ions. The presence of Tn551 at one location in the chromosome of Staphylococcus aureus enhances the frequency of suppression of thermosensitivity of replication of the plasmids pS1 and p delta D which are derivatives of pI9789::Tn552. Bacteriophage propagated on the bacteria in which thermosensitivity of replication had been suppressed was used to transduce cadmium resistance to S. aureus PS80N. The cadmium-resistant transductants obtained carried plasmid pS1 or p delta D with a copy of Tn551 inserted into a specific site on pS1 but into several different sites on p delta D. The possible mechanisms of the suppression are discussed. | 1995 | 7758929 |
| 369 | 18 | 0.9623 | A gene fusion system using the aminoglycoside 3'-phosphotransferase gene of the kanamycin-resistance transposon Tn903: use in the yeast Kluyveromyces lactis and Saccharomyces cerevisiae. The aminoglycoside 3'-phosphotransferase type I (APHI)-coding gene of the bacterial transposon Tn903 confers resistance to kanamycin on bacteria and resistance to geneticin (G418) on many eukaryotes. We developed an APHI fusion system that can be used in the study of gene expression in these organisms, particularly in yeasts. The first 19 codons of the KmR (APHI) gene can be deleted, and replaced by other genes in a continuous reading frame, without loss of APH activity. Examples of vector constructions are given which are adapted to the yeast Kluyveromyces lactis transformation system. Their derivatives containing the 2 mu origin of replication can also be used in Saccharomyces cerevisiae. | 1988 | 2853096 |
| 3055 | 19 | 0.9623 | Tn1545: a conjugative shuttle transposon. Tn1545, from Streptococcus pneumoniae BM4200, confers resistance to kanamycin (aphA-3), erythromycin (ermAM) and tetracycline (tetM). The 25.3 kb element is self-transferable to various Gram-positive bacterial genera where it transposes. Tn1545 was cloned in its entirety in the recombination deficient Escherichia coli HB101 where it was unstable. The three resistance genes aphA-3, ermAM and tetM were expressed but were not transferable to other E. coli cells. Tn1545 transposed from the hybrid plasmid to multiple sites of the chromosome of its new host. The element re-transposed, at a frequency of 5 X 10(-9), from the chromosome to various sites of a conjugative plasmid where it could be lost by apparently clean excision. The element transformed and transposed to the chromosome of Bacillus subtilis. The properties of the conjugative shuttle transposon Tn1545 may account for the recent emergence of genes from Gram-positive bacteria in Gram-negative organisms. | 1987 | 3035335 |