# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 3049 | 0 | 1.0000 | 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 |
| 3053 | 1 | 0.9992 | 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 | 2 | 0.9992 | 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 |
| 3044 | 3 | 0.9991 | 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 |
| 3045 | 4 | 0.9991 | Plasmid-borne sulfonamide resistance determinants studied by restriction enzyme analysis. The relationship between sulfonamide resistance genes carried on different plasmids was investigated by restriction enzyme analysis and DNA-DNA hybridization. The results showed that sulfonamide resistance mediated by different plasmids is determined by the production of at least two different types of drug-resistant dihydropteroate synthase. Plasmids pGS01, pGS02, and R22259, found in bacteria isolated from patients in Swedish hospitals, contained identical sulfonamide resistance genes, which were also identical to those of plasmids R1, R100, R6, and R388. These latter plasmids, which have been well studied in different laboratories, were originally from clinical isolates from different parts of the world. Two other clinically isolated plasmids, pGS04 and pGS05, were shown to contain sulfonamide resistance determinants of a completely different type. | 1983 | 6298179 |
| 3052 | 5 | 0.9991 | Expression of antibiotic resistance genes from Escherichia coli in Bacillus subtilis. Bifunctional recombinant plasmids were constructed, comprised of the E. coli vectors pBR322, pBR325 and pACYC184 and different plasmids from Gram-positive bacteria, e.g. pBSU161-1 of B. subtilis and pUB110 and pC221 of S. aureus. The beta-lactamase (bla) gene and the chloramphenicol acetyltransferase (cat) gene from the E. coli plasmids were not transcribed and therefore not expressed in B. subtilis. However, tetracycline resistance from the E. coli plasmids was expressed in B. subtilis. Transcription of the tetracycline resistance gene(s) started in B. subtilis at or near the original E. coli promoter, the sequence of which is almost identical with the sequence recognized by sigma 55 of B. subtilis RNA polymerase. | 1983 | 6410152 |
| 361 | 6 | 0.9990 | Plasmid transfer from Escherichia coli to Bacteroides fragilis: differential expression of antibiotic resistance phenotypes. A unique shuttle plasmid, pDP1, has been constructed to mediate gene transfer between Escherichia coli and the Gram-negative anaerobe Bacteroides fragilis. pDP1 contains the pBR322 replicon and the Bacteroides clindamycin resistance plasmid pCP1 linked to the transfer origin of the broad host range plasmid RK2. pDP1 can be transferred from E. coli to B. fragilis by the RK2 conjugation system even though RK2 itself is not maintained in the Bacteroides recipients. The antibiotic resistance and replication functions of pDP1 have been mapped by deletion analysis, and a 5-kilobase portion of the plasmid has been identified as the essential region for maintenance in Bacteroides. Comparison of the resistance conferred by pDP1 on E. coli and B. fragilis shows that antibiotic resistance genes are expressed differently in aerobic and anaerobic bacteria. These results document the feasibility of gene transfer from E. coli to B. fragilis and demonstrate the usefulness of this conjugation system to study genetic structure and expression in Bacteroides. | 1984 | 6095273 |
| 3055 | 7 | 0.9990 | 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 |
| 431 | 8 | 0.9990 | 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 |
| 3046 | 9 | 0.9990 | 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 |
| 5864 | 10 | 0.9989 | Characterization of the tetracycline resistance plasmid pMD5057 from Lactobacillus plantarum 5057 reveals a composite structure. The 10,877bp tetracycline resistance plasmid pMD5057 from Lactobacillus plantarum 5057 was completely sequenced. The sequence revealed a composite structure containing DNA from up to four different sources. The replication region had homology to other plasmids of lactic acid bacteria while the tetracycline resistance region, containing a tet(M) gene, had high homology to sequences from Clostridium perfringens and Staphylococcus aureus. Within the tetracycline resistance region a Lactobacillus IS-element was found. The remaining part of the plasmid contained three open reading frames with unknown functions. The composite structure with several truncated genes suggests a recent assembly of the plasmid. This is the first sequence of an antibiotic resistance plasmid isolated from L. plantarum. | 2002 | 12383727 |
| 3043 | 11 | 0.9989 | The role of insertions, deletions, and substitutions in the evolution of R6 related plasmids encoding aminoglycoside transferase ANT-(2"). In 7% of gram-negative bacteria resistance to gentamicin is mainly mediated by plasmid-encoded aminoglycoside transferase ANT-(2"). The genome organization of 15 aadB plasmids (42-110 kb) was analyzed by restriction and hybridization techniques. They appeared to be IncFII-like replicons but were distinct from R6 by virtue of small substitutions in the transfer region. Aminoglycoside resistance genes aadB and aadA were located on Tn21 related elements. Only one of them was able to transpose its resistance genes mer sul aadA and aadB ( Tn4000 ), the other elements were naturally occurring defective transposons. In some of these structures deletions were identified at the termini, at sul, aadA , mer or transposition function--insertions adjacent to aadA or mer. The mode of these rearrangements and their site-specificity were considered with respect to the evolution of the Tn21 transposon family. | 1984 | 6328217 |
| 3050 | 12 | 0.9989 | 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 |
| 379 | 13 | 0.9989 | Broad host range DNA cloning system for gram-negative bacteria: construction of a gene bank of Rhizobium meliloti. A broad host range cloning vehicle that can be mobilized at high frequency into Gram-negative bacteria has been constructed from the naturally occurring antibiotic resistance plasmid RK2. The vehicle is 20 kilobase pairs in size, encodes tetracycline resistance, and contains two single restriction enzyme sites suitable for cloning. Mobilization is effected by a helper plasmid consisting of the RK2 transfer genes linked to a ColE1 replicon. By use of this plasmid vehicle, a gene bank of the DNA from a wild-type strain of Rhizobium meliloti has been constructed and established in Escherichia coli. One of the hybrid plasmids in the bank contains a DNA insert of approximately 26 kilobase pairs which has homology to the nitrogenase structural gene region of Klebsiella pneumoniae. | 1980 | 7012838 |
| 4499 | 14 | 0.9989 | Organization of two sulfonamide resistance genes on plasmids of gram-negative bacteria. The organization of two widely distributed sulfonamide resistance genes has been studied. The type I gene was linked to other resistance genes, like streptomycin resistance in R100 and trimethoprim resistance in R388 and other recently isolated plasmids from Sri Lanka. In R388, the sulfonamide resistance gene was transcribed from a promoter of its own, but in all other studied plasmids the linked genes were transcribed from a common promoter. This was especially established with a clone derived from plasmid R6-5, in which transposon mutagenesis showed that expression of sulfonamide resistance was completely dependent on the linked streptomycin resistance gene. The type II sulfonamide resistance gene was independently transcribed and found on two kinds of small resistance plasmids and also on large plasmids isolated from clinical material. | 1987 | 3032095 |
| 4503 | 15 | 0.9989 | Evolution and transfer of aminoglycoside resistance genes under natural conditions. 3'-Aminoglycoside phosphotransferases [APH(3')] were chosen as a model to study the evolution and the transfer of aminoglycoside resistance genes under natural conditions. Comparison of the amino acid sequences of APH(3') enzymes from transposons Tn903 (type I) and Tn5 (type II) detected in Gram-negative bacteria, from the Gram-positive Staphylococcus and Streptococcus (type III), from the butirosin-producing Bacillus circulans (type IV) and from a neomycin-producing Streptomyces fradiae (type V) indicate that they have diverged from a common ancestor. These structural data support the hypothesis that the antibiotic-producing strains were the source of certain resistance determinants. We have shown that kanamycin resistance in Campylobacter coli BM2509 was due to the synthesis of an APH(3')-III, an enzyme not detected previously in a Gram-negative bacterium. The genes encoding APH(3')-III in Streptococcus and Campylobacter are identical. These findings constitute evidence for a recent in-vivo transfer of DNA between Gram-positive and Gram-negative bacteria. | 1986 | 3027020 |
| 430 | 16 | 0.9989 | Cloning and characterization of EcoRI and HindIII restriction endonuclease-generated fragments of antibiotic resistance plasmids R6-5 and R6. DNA fragments generated by the EcoRI of HindIII endonucleases from the low copy number antibiotic resistance plasmids R6 and R6-5 were separately cloned using the high copy number ColE1 or pML21 plasmid vectors and the insertional inactivation procedure. The hybrid plasmids that were obtained were used to determine the location of the EcoRI and HindIII cleavage sites on the parent plasmid genomes by means of electron microscope heteroduplex analysis and agarose gel electrophoresis. Ultracentrifugation of the cloned fragments in caesium chloride gradients localized the high buoyant density regions of R6-5 to fragments that carry the genes for resistance to streptomycin-spectinomycin, sulfonamide, and mercury and a low buoyant density region to fragments that carry the tetracycline resistance determinant. Functional analysis of hybrid plasmids localized a number of plasmid properties such as resistances to antibiotics and mercury and several replication functions to specific regions of the R6-5 genome. Precise localisation of the genes for resistance to chloramphenicol, kanamycin, fusidic acid and tetracycline was possible due to the presence of identified restriction endonuclease cleavage sites within these determinants. Only one region competent for autonomous replication was identified on the R6-5 plasmid genome and this was localized to EcoRI fragment 2 and HindIII fragment 1. However, two additional regions of replication activity designated RepB and RepC, themselves incapable of autonomous replication but capable supporting replication of a linked ColE1 plasmid in polA- bacteria, were also identified. | 1978 | 672900 |
| 429 | 17 | 0.9989 | An integrative vector exploiting the transposition properties of Tn1545 for insertional mutagenesis and cloning of genes from gram-positive bacteria. We have constructed and used an integrative vector, pAT112, that takes advantage of the transposition properties (integration and excision) of transposon Tn1545. This 4.9-kb plasmid is composed of: (i) the replication origin of pACYC184; (ii) the attachment site (att) of Tn1545; (iii) erythromycin-and kanamycin-resistance-encoding genes for selection in Gram- and Gram+ bacteria; and (iv) the transfer origin of IncP plasmid RK2, which allows mobilization of the vector from Escherichia coli to various Gram+ recipients. Integration of pAT112 requires the presence of the transposon-encoded integrase, Int-Tn, in the new host. This vector retains the insertion specificity of the parental element Tn1545 and utilises it to carry out insertional mutagenesis, as evaluated in Enterococcus faecalis. Since pAT112 contains the pACYC184 replicon and lacks most of the restriction sites that are commonly used for molecular cloning, a gene from a Gram+ bacterium disrupted with this vector can be recovered in E. coli by cleavage of genomic DNA, intramolecular ligation and transformation. Regeneration of the gene, by excision of pAT112, can be obtained in an E. coli strain expressing the excisionase and integrase of Tn1545. The functionality of this system was illustrated by characterization of an IS30-like structure in the chromosome of En. faecalis. Derivatives pAT113 and pAT114 contain ten unique cloning sites that allow screening of recombinants having DNA inserts by alpha-complementation in E. coli carrying the delta M15 deletion of lacZ alpha. These vectors are useful to clone and introduce foreign genes into the genomes of Gram+ bacteria. | 1991 | 1657722 |
| 3040 | 18 | 0.9989 | Similarity in the Structure of tetD-Carrying Mobile Genetic Elements in Bacterial Strains of Different Genera Isolated from Cultured Yellowtail. Structure analysis was performed on the antibiotic-resistance-gene region of conjugative plasmids of four fish farm bacteria.The kanamycin resistance gene, IS26, and tetracycline resistance gene (tetA(D)) were flanked by two IS26s in opposite orientation in Citrobacter sp. TA3 and TA6, and Alteromonas sp. TA55 from fish farm A. IS26-Inner was disrupted with ISRSB101. The chloramphenicol resistance gene, IS26 and tetA (D) were flanked by two IS26s in direct orientation in Salmonella sp. TC67 from farm C. Structures of tetA (D) and IS26 were identical among the four bacteria, but there was no insertion within the IS26-Inner of Salmonella sp. TC67. Horizontal gene transfer between the strains of two different genera in fish farm A was suggested by the structure homologies of mobile genetic elements and antibiotic resistance genes. | 2016 | 27667524 |
| 3042 | 19 | 0.9988 | Aminoglycoside acetyltransferase 3-IV (aacC4) and hygromycin B 4-I phosphotransferase (hphB) in bacteria isolated from human and animal sources. Members of the family Enterobacteriaceae harboring an enzyme of the aminoglycoside acetyltransferase 3 class (AAC-3-IV) (apramycin and gentamicin resistance) and hygromycin B phosphotransferase 4 (HPH-4-I) (hygromycin B resistance) have been isolated from human clinical sources in Europe. A cluster of genes containing IS140, aacC4, and hphB was found in these strains. We demonstrate by Southern hybridization that this cluster is identical to the operon found in animals that also contains insertion sequences belonging to the ISO family. This provides another example of presumptive transfer of antibiotic resistance genes between bacteria of animal and human origin. | 1990 | 1963287 |